M. Mihai, A. Holban, C. Giurcaneanu et al.

Current Topics in Medicinal Chemistry • 2015

The majority of chronic infections are associated with mono- or polymicrobial biofilms, having a significant impact on the patients' quality of life and survival rates. Although the use of medical devices revolutionized health care services and significantly improved patient outcomes, it also led to complications associated with biofilms and to the emergence of multidrug resistant bacteria. Immunocompromised patients, institutionalized or hospitalized individuals, elderly people are at greater risk due to life-threatening septic complications, but immunocompetent individuals with predisposing genetic or acquired diseases can also be affected, almost any body part being able to shelter persistent biofilms. Moreover, chronic biofilm-related infections can lead to the occurrence of systemic diseases, as in the case of chronic periodontitis, linked to atherosclerosis, cardiovascular disease and diabetes. The more researchers discover, new unknown issues add up to the complexity of biofilm infections, in which microbial species establish relationships of cooperation and competition, and elaborate phenotypic differentiation into functional, adapted communities. Their interaction with the host's immune system or with therapeutic agents contributes to the complex puzzle that still misses a lot of pieces. In this comprehensive review we aimed to highlight the microbial composition, developmental stages, architecture and properties of medical biofilms, as well as the diagnostic tools used in the management of biofilm related infections. Also, we present recently acquired knowledge on the etiopathogenesis, diagnosis and treatment of four chronic diseases associated with biofilm development in tissues (chronic periodontitis, chronic lung infection in cystic fibrosis, chronic wounds) and artificial substrata (medical devices-related infections).

R. Žalnėravičius, A. Paškevičius, U. Samukaite-Bubniene et al.

Biosensors • 2022

In this study, the nitrogen-fixing, Gram-negative soil bacteria Rhizobium anhuiense was successfully utilized as the main biocatalyst in a bacteria-based microbial fuel cell (MFC) device. This research investigates the double-chambered, H-type R. anhuiense-based MFC that was operated in modified Norris medium (pH = 7) under ambient conditions using potassium ferricyanide as an electron acceptor in the cathodic compartment. The designed MFC exhibited an open-circuit voltage (OCV) of 635 mV and a power output of 1.07 mW m−2 with its maximum power registered at 245 mV. These values were further enhanced by re-feeding the anode bath with 25 mM glucose, which has been utilized herein as the main carbon source. This substrate addition led to better performance of the constructed MFC with a power output of 2.59 mW m−2 estimated at an operating voltage of 281 mV. The R. anhuiense-based MFC was further developed by improving the charge transfer through the bacterial cell membrane by applying 2-methyl-1,4-naphthoquinone (menadione, MD) as a soluble redox mediator. The MD-mediated MFC device showed better performance, resulting in a slightly higher OCV value of 683 mV and an almost five-fold increase in power density to 4.93 mW cm−2. The influence of different concentrations of MD on the viability of R. anhuiense bacteria was investigated by estimating the optical density at 600 nm (OD600) and comparing the obtained results with the control aliquot. The results show that lower concentrations of MD, ranging from 1 to 10 μM, can be successfully used in an anode compartment in which R. anhuiense bacteria cells remain viable and act as a main biocatalyst for MFC applications.

T. Kremer, Jeff Felgar, Neil Rowen et al.

Biomedical Instrumentation & Technology • 2023

The identification of worst-case device (or device set) features has been a well-established validation approach in many areas (e.g., terminal sterilization) for determining process effectiveness and requirements, including for reusable medical devices. A device feature approach for cleaning validations has many advantages, representing a more conservative approach compared with the alternative compendial method of testing the entirety of the device. By focusing on the device feature(s), the most challenging validation variables can be isolated to and studied at the most difficult-to-clean feature(s). The device feature approach can be used to develop a design feature database that can be used to design and validate device cleanliness. It can also be used to commensurately develop a quantitative cleaning classification system that will augment and innovate the effectiveness of the Spaulding classification for microbial risk reduction. The current study investigated this validation approach to verify the efficacy of device cleaning procedures and mitigate patient risk. This feature categorization approach will help to close the existing patient safety gap at the important interface between device manufacturers and healthcare facilities for the effective and reliable processing of reusable medical devices. A total of 56,000 flushes of the device features were conducted, highlighting the rigor associated with the validation. Generating information from design features as a critical control point for cleaning and microbiological quality will inform future digital transformation of the medical device industry and healthcare delivery, including automation.

P. L. Chong, Joon Huang Chuah, C. Chow et al.

International Journal of Green Energy • 2024

ABSTRACT This review delves into the multifaceted landscape of plant microbial fuel cells (PMFCs), investigating the affecting factors, configurations, applications, challenges, and prospects that shape their design. A thorough exploration of the affecting factors covering natural factors such as type of living plants, type of microbes and environmental factors as well as man-made factors such as electrode material and design, addition of additives and the diverse array of PMFC configurations are investigated here. The configurations cover the tubular design, flat plate design, sediment type, green rooftop design, constructed wetland and bryophyte PMFC are analyzed for performance comparison, offering insights for researchers. Applications of PMFC for powering ultra-low power remote devices and sensors, biosensing purposes, wastewater treatment, to bioremediation of polluted sites, are showcased to show the versatility of PMFCs. Despite their promise, challenges such as low power output, plant selection and growth, control over microbial species, diversity and electron transfer mechanisms, the long-term stability and durability of PMFC as well as scalability and cost for wide implementation of PMFC, are conversed here as it necessitates innovative solutions. In addition, this paper also provides recommendation of prospects to be considered by future researchers to enhance the development of PMFC.

Yuvraj Maphrio Mao, Aarya Garg, Khairunnisa Amreen et al.

2023 16th International Conference on Sensing Technology (ICST) • 2023

Fiber-based Microbial Fuel Cells (MFCs) are emerging as promising technology in the field of fuel cells. Due, to the features like its inexpensive nature, naivety in fabrication, and its abundance of availability they manifest an upper edge over the other fluidic-based MFCs. Fiber-based MFCs are the epitome of an electrochemical system that uses bacteria for power generation and wastewater treatment in the paper substrate. Fiber-based miniaturized devices have gained significant attention over the last few years due to their flexible application in medical science, biosensors, etc. This work fabricated paper-based miniaturized MFCs using a 3D printer. Carbon Cloth was used as the working electrode and Pseudomonas Aeruginosa (Pseudomonas A) as the fuel to generate power. A comparative study showed that the fiber treated in oxygen plasma showed an optimized power output of around 345.40 µW/cm2 and a current output of 20.95 µA/cm2.

A. Mohamed, T. Ewing, S. Lindemann et al.

Journal of The Electrochemical Society • 2017

The performance of sediment microbial fuel cells (SMFCs) in the field must be evaluated prior to their being relied on as a power source for sensor networks. Currently, the ability to perform such evaluation is limited. The goal of this work was to develop an autonomous, battery-powered, low-cost device (a remote sediment microbial fuel cell tester, or RSMFCT) that can evaluate the field performance of SMFCs charging capacitors in remote areas. The developed RSMFCT allows an SMFC to charge a capacitor between preset charge and discharge potentials and monitors anode and cathode potentials, capacitor potential, and temperature. The RSMFCT was tested at a remote location in the Hot Lake Research Natural Area, near Oroville,WA, USA and used to evaluate the optimum conditions for operating an SMFC. Using the recorded data, the average power and frequency of cycle were determined. We found that SMFCs deployed in Hot Lake operated optimally when charging a 5-F capacitor from 300 mV to 400 mV. Under these conditions, the SMFCs produced an average daily power of 10.28 μW and required an average capacitor charging time of 3.08 hours. We conclude that the RSMFCT is practical for: 1) determining the optimum operation parameters, those that maximize the power output of SMFCs in field operation, and 2) reliably incorporating individual SMFCs as power sources for remote sensor networks by allowing the prediction of their power output and frequency of charge cycles. © The Author(s) 2016. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. [DOI: 10.1149/2.0041703jes] All rights reserved.

I. Sulaiman, P. Banerjee, Ying-hsin Hsieh et al.

Journal of AOAC INTERNATIONAL • 2018

Staphylococcus spp. is considered as one of the most common human-pathogenic bacteria, causing illnesses ranging from nonthreatening skin infections to lethal diseases, including sepsis, pneumonia, bloodstream infections, and food poisoning. The emergence of methicillin-resistant Staphylococcus aureus strains has increased morbidity and mortality and resulted in a major healthcare burden worldwide. Single and multilocus sequence typing have been extensively used in the identification of Staphylococcus species. Nevertheless, these assays are relatively time-consuming and require high-quality DNA. Matrix-assisted laser desorption ionization-time-of-flight has been used recently for the rapid identification of several bacterial species. In this study, we have examined 47 Staphylococcus isolates recovered from food, environment, clinical samples, cosmetic products, and a medical device and 3 American Type Culture Collection Staphylococcus reference isolates using bioMérieux VITEK MS and VITEK 2 systems to determine isolate identity. Sequencing of the 16S ribosomal RNA gene was performed to confirm and compare the species identification data generated by VITEK 2 and VITEK MS systems. Although the VITEK 2 system could not identify one of the isolates, VITEK MS identified all 50 Staphylococcus spp. isolates tested. Results of this study clearly suggest that VITEK MS can be used in the rapid identification of Staphylococcus isolates of public health importance.

Shi-Hang Wang, Jian-Wei Wang, Li-ting Zhao et al.

Biosensors • 2023

Soil microbial fuel cells (SMFCs) are an innovative device for soil-powered biosensors. However, the traditional SMFC sensors relied on anodic biosensing which might be unstable for long-term and continuous monitoring of toxic pollutants. Here, a carbon-felt-based cathodic SMFC biosensor was developed and applied for soil-powered long-term sensing of heavy metal ions. The SMFC-based biosensor generated output voltage about 400 mV with the external load of 1000 Ω. Upon the injection of metal ions, the voltage of the SMFC was increased sharply and quickly reached a stable output within 2~5 min. The metal ions of Cd2+, Zn2+, Pb2+, or Hg2+ ranging from 0.5 to 30 mg/L could be quantified by using this SMFC biosensor. As the anode was immersed in the deep soil, this SMFC-based biosensor was able to monitor efficiently for four months under repeated metal ions detection without significant decrease on the output voltage. This finding demonstrated the clear potential of the cathodic SMFC biosensor, which can be further implemented as a low-cost self-powered biosensor.

Roszita Ibrahim, N. Shaari, Azana Hafizah Mohd Aman

International Journal of Energy Research • 2021

Fuel cells efficiently turn chemicals in fuel into electricity by chemical reaction and have been described as among the most recent advances in the upcoming cleaner energy sector. In recent times, fuel cells are being used in medicine, including experimental studies and current and potential goods, having numerous benefits over previous batteries, such as the convenience of recharging, eco‐sustainable character, and high safety. This article highlights the up‐to‐date development of this energy system focusing on biofuel cells in implantable medical devices (IMDs) that use microbes, enzymes, and noble metals as catalysts. Furthermore, a diversity of fuel cell applications on the vitro medical kit (including alcohol tester, wound treatment instrument, blood glucose meter) was also described. The integration of fuel cells into implementable medical devices is at an initial phase of research, but this technology's possibility and potency is a reward. Obviously, after successfully integrating fuel cells into the patient's psyche, civilization will move throughout an innovative diagnostic transition.

Mummaka Harshavardhan, Prashant Sakhavalkar, Attarde Viren Bhaskar

International Journal of Medical and Biomedical Studies • 2024

Background: Medical device-associated infections (MDAIs) are a major healthcare concern due to their high morbidity, mortality, and rising prevalence of MDR and XDR bacteria. This study examined the microbiological composition, antimicrobial susceptibility, and prevalence of MDR/XDR infections in MDAI patients at Dr. D.Y. Patil Medical College, Pune. Methods: One-year retrospective research included 100 MDAI patients. Antimicrobial susceptibility testing was done on microbial isolates from blood, urine, and wound swabs according to CLSI standards. The prevalence of MDR and XDR pathogens was determined. Results: Escherichia coli (30%) and Klebsiella pneumoniae (20%) caused most infections, while Staphylococcus aureus (25%) was the most common Gram-positive bacteria. Antimicrobial susceptibility testing showed that 40% of the isolates were MDR and 15% were XDR. Klebsiella pneumoniae had the highest resistance rate (70%), followed by Pseudomonas aeruginosa. Conclusion: The study shows that MDAIs are dominated by MDR and XDR infections, mainly Gram-negative bacteria, making therapy difficult. These findings highlight the critical need for improved infection control, antimicrobial stewardship, and regular surveillance to address medical device-associated resistance infections. Keywords: Medical device infections, multidrug-resistant, extensively drug-resistant organisms, antimicrobial susceptibility, microbiological profile, healthcare-associated infections.

Akanksha Mishra, Ashish Aggarwal, Fazlurrahman Khan

Antibiotics • 2024

Hospital-acquired infections, also known as nosocomial infections, include bloodstream infections, surgical site infections, skin and soft tissue infections, respiratory tract infections, and urinary tract infections. According to reports, Gram-positive and Gram-negative pathogenic bacteria account for up to 70% of nosocomial infections in intensive care unit (ICU) patients. Biofilm production is a main virulence mechanism and a distinguishing feature of bacterial pathogens. Most bacterial pathogens develop biofilms at the solid-liquid and air-liquid interfaces. An essential requirement for biofilm production is the presence of a conditioning film. A conditioning film provides the first surface on which bacteria can adhere and fosters the growth of biofilms by creating a favorable environment. The conditioning film improves microbial adherence by delivering chemical signals or generating microenvironments. Microorganisms use this coating as a nutrient source. The film gathers both inorganic and organic substances from its surroundings, or these substances are generated by microbes in the film. These nutrients boost the initial growth of the adhering bacteria and facilitate biofilm formation by acting as a food source. Coatings with combined antibacterial efficacy and antifouling properties provide further benefits by preventing dead cells and debris from adhering to the surfaces. In the present review, we address numerous pathogenic microbes that form biofilms on the surfaces of biomedical devices. In addition, we explore several efficient smart antiadhesive coatings on the surfaces of biomedical device-relevant materials that manage nosocomial infections caused by biofilm-forming microbial pathogens.

D. Roxby, Nham Tran, Pak-Lam Yu et al.

2016 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) • 2016

Implanted biomedical devices typically last a number of years before their batteries are depleted and a surgery is required to replace them. A Microbial Fuel Cell (MFC) is a device which by using bacteria, directly breaks down sugars to generate electricity. Conceptually there is potential to continually power implanted medical devices for the lifetime of a patient. To investigate the practical potential of this technology, H-Cell Dual Chamber MFCs were evaluated with two different growth solutions and measurements recorded for maximum power output both of individual MFCs and connected MFCs. Using Luria-Bertani media and connecting MFCs in a hybrid series and parallel arrangement with larger membrane sizes showed the highest power output and the greatest potential for replacing implanted batteries.

Guey-Horng Wang, Chiu-Yu Cheng, Man-Hai Liu et al.

Sensors • 0

<jats:p>Fast hexavalent chromium (Cr(VI)) determination is important for environmental risk and health-related considerations. We used a microbial fuel cell-based biosensor inoculated with a facultatively anaerobic, Cr(VI)-reducing, and exoelectrogenic Ochrobactrum anthropi YC152 to determine the Cr(VI) concentration in water. The results indicated that O. anthropi YC152 exhibited high adaptability to pH, temperature, salinity, and water quality under anaerobic conditions. The stable performance of the microbial fuel cell (MFC)-based biosensor indicated its potential as a reliable biosensor system. The MFC voltage decreased as the Cr(VI) concentration in the MFC increased. Two satisfactory linear relationships were observed between the Cr(VI) concentration and voltage output for various Cr(VI) concentration ranges (0.0125–0.3 mg/L and 0.3–5 mg/L). The MFC biosensor is a simple device that can accurately measure Cr(VI) concentrations in drinking water, groundwater, and electroplating wastewater in 45 min with low deviations (&lt;10%). The use of the biosensor can help in preventing the violation of effluent regulations and the maximum allowable concentration of Cr(VI) in water. Thus, the developed MFC biosensor has potential as an early warning detection device for Cr(VI) determination even if O. anthropi YC152 is a possible opportunistic pathogen.</jats:p>

Siyang Shen, Yen‐Han Lin, Chenguang Liu

The Canadian Journal of Chemical Engineering • 2024

<jats:title>Abstract</jats:title><jats:p>In this work, we demonstrate a novel design that integrates a modified Nernst equation and readings from a microbial fuel cell (MFC)‐based device, facilitating real‐time monitoring of microbial growth. The MFC‐based device is comprised of an H‐shaped double‐chamber MFC, specifically designed to incorporate an oxidation–reduction potential (ORP) sensor, allowing for simultaneous measurements of both parameters. The Nernst equation was adjusted to assimilate readings from both the ORP sensor and the MFC device, ultimately deriving a unitless curve that represents the online dynamics of microbial growth. This curve exhibits two distinct peaks: the first peak indicates the initiation of the exponential phase, while the second peak signals its termination. The proposed design can be seamlessly integrated into fermentation processes to continually monitor progress, boost productivity, develop tailored control strategies that meet specific objectives, and so on.</jats:p>

Dawid Zawadzki, Paulina Pędziwiatr, Karina Michalska

Acta Innovations • 2018

<jats:p>Research about exploitation the potential of waste and sludge increased drastically in the recent years. One of the most promising alternative methods of waste management is Microbial Fuel Cell (MFC), which generate clean bio-electricity using microorganisms. Organic compounds, sewage, municipal solid waste could be used as a source for microbial nutrition. The construction of MFC is one of the most important parameter in laboratory studies and during scale-up. The efficiency of MFC depends on many factors including type of membrane. To obtain optimization in terms of various operating conditions, a prototype of Microbial Fuel Cell with exchangeable membrane was projected and fabricated by additive manufacturing (AM) technology. This novel device allows to research effects of different types of separator membranes. Preliminary research showed possibility to produce 3D printed MFC systems.</jats:p>

S. Abou Fayssal, Z. El Sebaaly, Y. Sassine

Foods • 2023

The short shelf-life of mushrooms, due to water loss and microbial spoilage, is the main constraint for commercialization and consumption. The effect of substrate type combined with different temperatures and packaging conditions on the shelf-life of fresh Pleurotus ostreatus is scantily researched. The current study investigated the shelf-life of fresh oyster mushrooms grown on low (0.3, 0.3, 0.17) and high (0.7, 0.7, 0.33) rates of olive pruning residues (OLPR), spent coffee grounds (SCG), and both combined residues (OLPR/SCG) with wheat straw (WS), respectively, at ambient (20 °C) and 4 °C temperatures under no packaging, polyethylene plastic bag packaging (PBP), and polypropylene vacuum bag packaging (VBP). Results showed that at ambient temperature OLPR/SCG mushrooms PBP-bagged had an increased shelf-life by 0.5–1.2 days in comparison with WS ones. The predictive models adopted to optimize mushroom shelf-life at ambient temperature set rates of 0.289 and 0.303 of OLPR and OLPR/SCG, respectively, and PBP as the most suitable conditions (9.18 and 9.14 days, respectively). At 4 °C, OLPR/SCG mushrooms VBP-bagged had a longer shelf-life of 2.6–4.4 days compared to WS ones. Predictive models noted a maximized shelf-life of VBP-bagged mushrooms (26.26 days) when a rate of 0.22 OLPR/SCG is incorporated into the initial substrate. The combination of OLPR and SCG increased the shelf-life of fresh Pleurotus ostreatus by decreasing the total microbial count (TMC) while delaying weight loss and veil opening, and maintaining carbohydrate content, good firmness, and considerable protein, in comparison with WS regardless the storage temperature and packaging type.

M. S. Santos, M. Nogueira, M. Hungria

AMB Express • 2019

More than one hundred years have passed since the development of the first microbial inoculant for plants. Nowadays, the use of microbial inoculants in agriculture is spread worldwide for different crops and carrying different microorganisms. In the last decades, impressive progress has been achieved in the production, commercialization and use of inoculants. Nowadays, farmers are more receptive to the use of inoculants mainly because high-quality products and multi-purpose elite strains are available at the market, improving yields at low cost in comparison to chemical fertilizers. In the context of a more sustainable agriculture, microbial inoculants also help to mitigate environmental impacts caused by agrochemicals. Challenges rely on the production of microbial inoculants for a broader range of crops, and the expansion of the inoculated area worldwide, in addition to the search for innovative microbial solutions in areas subjected to increasing episodes of environmental stresses. In this review, we explore the world market for inoculants, showing which bacteria are prominent as inoculants in different countries, and we discuss the main research strategies that might contribute to improve the use of microbial inoculants in agriculture.

Kevin Tian Xiang Tong, I. Tan, H. Foo et al.

Bioengineered • 2023

ABSTRACT The imminent need for transition to a circular biorefinery using microbial fuel cells (MFC), based on the valorization of renewable resources, will ameliorate the carbon footprint induced by industrialization. MFC catalyzed by bioelectrochemical process drew significant attention initially for its exceptional potential for integrated production of biochemicals and bioenergy. Nonetheless, the associated costly bioproduct production and slow microbial kinetics have constrained its commercialization. This review encompasses the potential and development of macroalgal biomass as a substrate in the MFC system for L-lactic acid (L-LA) and bioelectricity generation. Besides, an insight into the state-of-the-art technological advancement in the MFC system is also deliberated in detail. Investigations in recent years have shown that MFC developed with different anolyte enhances power density from several µW/m2 up to 8160 mW/m2. Further, this review provides a plausible picture of macroalgal-based L-LA and bioelectricity circular biorefinery in the MFC system for future research directions. Graphical Abstract

Dileep Sai Kumar Palur, Shannon R Pressley, S. Atsumi

Molecules • 2023

Human milk oligosaccharides (HMOs) are complex nonnutritive sugars present in human milk. These sugars possess prebiotic, immunomodulatory, and antagonistic properties towards pathogens and therefore are important for the health and well-being of newborn babies. Lower prevalence of breastfeeding around the globe, rising popularity of nutraceuticals, and low availability of HMOs have inspired efforts to develop economically feasible and efficient industrial-scale production platforms for HMOs. Recent progress in synthetic biology and metabolic engineering tools has enabled microbial systems to be a production system of HMOs. In this regard, the model organism Escherichia coli has emerged as the preferred production platform. Herein, we summarize the remarkable progress in the microbial production of HMOs and discuss the challenges and future opportunities in unraveling the scope of production of complex HMOs. We focus on the microbial production of five HMOs that have been approved for their commercialization.

Claire S. Baker, David C. Sands, H. Nzioki

Pest Management Science • 2023

The high-level view of global food systems identifies three all-encompassing barriers to the adoption of food systems solutions: knowledge, policy, and finance. These barriers, and the siloed characteristics of each of these, have hindered the development and adoption of microbial herbicides. How knowledge, policy, and finance are related to the Toothpick Project's path of commercializing a new bioherbicide, early in the scope of the industry, is discussed here. The Toothpick Project's innovation, developed over four decades and commercialized in 2021, uses strains of Fusarium oxysporum f.sp. strigae selected for overproduction and excretion of specific amino acids, killing the parasitic weed Striga hermonthica (Striga or witchweed), Africa's worst pest threat to food security. Historically, bioherbicides have not been a sufficient alternative to the dominant use of synthetic chemical herbicides. To be used safely as bioherbicides, plant pathogens need to be host specific, non-toxic, and yet sufficiently virulent to control a specific weed. For commercialization, bioherbicides must be affordable and require a sufficient shelf life for distribution. Given the current triple storm encountered by the chemical herbicide industry (herbicide-resistant weeds, lawsuits, and consumer pushback), there exists an opportunity to use certain plant pathogens as bioherbicides by enhancing their virulence. By discussing barriers in the scope of knowledge, policy, and finance in the development of the Toothpick Project's new microbial bioherbicide, we hope to help others to anticipate the challenges and provide change-leaders, particularly in policy and finance, a ground level perspective of bioherbicide development. This article is protected by copyright. All rights reserved.

Sebastian J. Ross, Gareth R Owen, James Hough et al.

Biotechnology and Bioengineering • 2024

Crop pests and pathogens annually cause over $220 billion in global crop damage, with insects consuming 5%–20% of major grain crops. Current crop pest and disease control strategies rely on insecticidal and fungicidal sprays, plant genetic resistance, transgenes, and agricultural practices. Double‐stranded RNA (dsRNA) is emerging as a novel sustainable method of plant protection as an alternative to traditional chemical pesticides. Successful commercialization of dsRNA‐based biocontrols requires the economical production of large quantities of dsRNA combined with suitable delivery methods to ensure RNAi efficacy against the target pest. In this study, we have optimized the design of plasmid DNA constructs to produce dsRNA biocontrols in Escherichia coli, by employing a wide range of alternative synthetic transcriptional terminators before measurement of dsRNA yield. We demonstrate that a 7.8‐fold increase of dsRNA was achieved using triple synthetic transcriptional terminators within a dual T7 dsRNA production system compared to the absence of transcriptional terminators. Moreover, our data demonstrate that batch fermentation production dsRNA using multiple transcriptional terminators is scalable and generates significantly higher yields of dsRNA generated in the absence of transcriptional terminators at both small‐scale batch culture and large‐scale fermentation. In addition, we show that application of these dsRNA biocontrols expressed in E. coli cells results in increased insect mortality. Finally, novel mass spectrometry analysis was performed to determine the precise sites of transcriptional termination at the different transcriptional terminators providing important further mechanistic insight.

A.K. Singh, Agendra Gangwar, Sanjay Kumar

Biofuels • 2024

Abstract Biofuels, including bioethanol, biogas, biohydrogen, and biodiesel, as well as microbial fuel cells, are extensively recognized as sustainable energy alternatives to fossil fuels. Nonetheless, their commercialization is constrained by various limitations, including economic and technological challenges. The integration of nanoparticles into biofuel production and microbial fuel cell fabrication has demonstrated significant benefits over time due to their nanoscale dimensions and distinctive structural properties. Their use enhances operational efficiency, increases yield, and accelerates the conversion of biomass into biofuels. This review presents a comprehensive global analysis of biofuels and includes a bibliometric analysis of research related to biofuels incorporating nanoparticles. It details the current production methods for various types of biofuels, their specific characteristics, production statistics, and existing gaps in their commercialization. This is followed by an in-depth examination of the role of nanotechnology in biofuel production and microbial fuel cell fabrication, supported by recent studies. The review thoroughly addresses the impact of nanotechnology from multiple perspectives, including environmental and human health considerations, scalability, effects on microbial communities, economic feasibility, and regulatory and ethical challenges. Mitigation strategies for these challenges are also discussed. Additionally, biofuels enhanced with nanoparticles are compared with other advanced technologies currently available. . .

João Vitor de Oliveira Barreto, L. Casanova, Athayde Neves Junior et al.

Microorganisms • 2023

Microbial pigments have many structures and functions with excellent characteristics, such as being biodegradable, non-toxic, and ecologically friendly, constituting an important source of pigments. Industrial production presents a bottleneck in production cost that restricts large-scale commercialization. However, microbial pigments are progressively gaining popularity because of their health advantages. The development of metabolic engineering and cost reduction of the bioprocess using industry by-products opened possibilities for cost and quality improvements in all production phases. We are thus addressing several points related to microbial pigments, including the major classes and structures found, the advantages of use, the biotechnological applications in different industrial sectors, their characteristics, and their impacts on the environment and society.

Ana Paula, Honrado Pinto, Jorge M. S. Faria et al.

Journal of Xenobiotics • 2023

Microbes hold immense potential, based on the fact that they are widely acknowledged for their role in mitigating the detrimental impacts of chemical fertilizers and pesticides, which were extensively employed during the Green Revolution era. The consequence of this extensive use has been the degradation of agricultural land, soil health and fertility deterioration, and a decline in crop quality. Despite the existence of environmentally friendly and sustainable alternatives, microbial bioinoculants encounter numerous challenges in real-world agricultural settings. These challenges include harsh environmental conditions like unfavorable soil pH, temperature extremes, and nutrient imbalances, as well as stiff competition with native microbial species and host plant specificity. Moreover, obstacles spanning from large-scale production to commercialization persist. Therefore, substantial efforts are underway to identify superior solutions that can foster a sustainable and eco-conscious agricultural system. In this context, attention has shifted towards the utilization of cell-free microbial exudates as opposed to traditional microbial inoculants. Microbial exudates refer to the diverse array of cellular metabolites secreted by microbial cells. These metabolites enclose a wide range of chemical compounds, including sugars, organic acids, amino acids, peptides, siderophores, volatiles, and more. The composition and function of these compounds in exudates can vary considerably, depending on the specific microbial strains and prevailing environmental conditions. Remarkably, they possess the capability to modulate and influence various plant physiological processes, thereby inducing tolerance to both biotic and abiotic stresses. Furthermore, these exudates facilitate plant growth and aid in the remediation of environmental pollutants such as chemicals and heavy metals in agroecosystems. Much like live microbes, when applied, these exudates actively participate in the phyllosphere and rhizosphere, engaging in continuous interactions with plants and plant-associated microbes. Consequently, they play a pivotal role in reshaping the microbiome. The biostimulant properties exhibited by these exudates position them as promising biological components for fostering cleaner and more sustainable agricultural systems.

Ashti Hosseini, Mahmoud Koushesh Saba, C. Watkins

Critical Reviews in Food Science and Nutrition • 2023

Abstract Postharvest waste due to decay of fruits and vegetables negatively affects food security, while at the same time control of decay and therefore waste can be limited because of consumer concerns about use of synthetic chemicals. Use of antagonistic microorganisms is an eco-friendly technique that represents a promising alternative approach to the use of chemical methods. Understanding the interactions between antagonists and the fruit microbiome will enable the discovery of new methods to reduce postharvest waste. This article reviews different microbial agents, fungi, bacteria and yeasts that could control decay. Recent developments in the use of microorganisms for preserving postharvest fruit quality, formulation of effective antagonists, and the commercialization steps are also discussed. Antagonists control decay through either direct or indirect mechanisms while preserving the appearance, flavor, texture and nutritional value of horticultural products. Microorganisms do not fully control pathogens, and therefore they are usually used with other treatments or have their biocontrol ability modified through genetic manipulations. Despite of these limitations, commercialization of biocontrol products based on antagonists with required stability and biocontrol potential is occurring. Biocontrol of postharvest decay and waste agent is promising technology for fruit and vegetable industries. Further study is necessary to better understand mechanisms and increasing efficiency of this method.

Shengtong Wan, Xin Liu, W. Sun et al.

Bioresources and Bioprocessing • 2023

Currently, microbial manufacturing is widely used in various fields, such as food, medicine and energy, for its advantages of greenness and sustainable development. Process optimization is the committed step enabling the commercialization of microbial manufacturing products. However, the present optimization processes mainly rely on experience or trial-and-error method ignoring the intrinsic connection between cellular physiological requirement and production performance, so in many cases the productivity of microbial manufacturing could not been fully exploited at economically feasible cost. Recently, the rapid development of omics technologies facilitates the comprehensive analysis of microbial metabolism and fermentation performance from multi-levels of molecules, cells and microenvironment. The use of omics technologies makes the process optimization more explicit, boosting microbial manufacturing performance and bringing significant economic benefits and social value. In this paper, the traditional and omics technologies-guided process optimization of microbial manufacturing are systematically reviewed, and the future trend of process optimization is prospected.

Rachel Backer, J. Rokem, Gayathri Ilangumaran et al.

Frontiers in Plant Science • 2018

Microbes of the phytomicrobiome are associated with every plant tissue and, in combination with the plant form the holobiont. Plants regulate the composition and activity of their associated bacterial community carefully. These microbes provide a wide range of services and benefits to the plant; in return, the plant provides the microbial community with reduced carbon and other metabolites. Soils are generally a moist environment, rich in reduced carbon which supports extensive soil microbial communities. The rhizomicrobiome is of great importance to agriculture owing to the rich diversity of root exudates and plant cell debris that attract diverse and unique patterns of microbial colonization. Microbes of the rhizomicrobiome play key roles in nutrient acquisition and assimilation, improved soil texture, secreting, and modulating extracellular molecules such as hormones, secondary metabolites, antibiotics, and various signal compounds, all leading to enhancement of plant growth. The microbes and compounds they secrete constitute valuable biostimulants and play pivotal roles in modulating plant stress responses. Research has demonstrated that inoculating plants with plant-growth promoting rhizobacteria (PGPR) or treating plants with microbe-to-plant signal compounds can be an effective strategy to stimulate crop growth. Furthermore, these strategies can improve crop tolerance for the abiotic stresses (e.g., drought, heat, and salinity) likely to become more frequent as climate change conditions continue to develop. This discovery has resulted in multifunctional PGPR-based formulations for commercial agriculture, to minimize the use of synthetic fertilizers and agrochemicals. This review is an update about the role of PGPR in agriculture, from their collection to commercialization as low-cost commercial agricultural inputs. First, we introduce the concept and role of the phytomicrobiome and the agricultural context underlying food security in the 21st century. Next, mechanisms of plant growth promotion by PGPR are discussed, including signal exchange between plant roots and PGPR and how these relationships modulate plant abiotic stress responses via induced systemic resistance. On the application side, strategies are discussed to improve rhizosphere colonization by PGPR inoculants. The final sections of the paper describe the applications of PGPR in 21st century agriculture and the roadmap to commercialization of a PGPR-based technology.

A. Fadiji, Chao Xiong, Eleonora Egidi et al.

Journal of Sustainable Agriculture and Environment • 2024

Sustainable increase in agriculture productivity is confronted by over‐reliance and over‐use of synthetic chemical fertilizers. With a market projection of $5.02 billion by 2030, biofertilizers are gaining momentum as a supplement and, in some cases, as an alternative to chemical fertilizers. Biofertilizers can improve the nutritional supply to the plant and simultaneously can improve soil health, reduce greenhouse emissions, and hence directly contribute towards environmental sustainability. Plant growth‐promoting microbes (PGPMs) are particularly receiving significant attention as biofertilizers. They are widely known for their ability to improve plant growth via increasing nutrient availability and use efficiency. However, except for a few successful cases, the commercialization of PGPM‐based inoculants is still limited, mainly due to lack of field efficacy and consistency. Lack of effective formulation technologies that keep microbial inoculants viable during storage, transport and field application is considered one of the key factors that drive inconsistent efficacy of microbial biofertilizers. In this review, we identify current challenges associated with the application and formulation of microbial inoculants. We propose future paths, including advancement in formulation technologies that are potentially efficient, eco‐friendly and cost‐effective. We argue that to enhance the global adoption of biofertilizers, new innovations based on transdisciplinary approaches are indispensable. The emerging framework should encompass a robust quality control system at all stages. Additionally, the active partnership between the academic and industry stakeholders will pave the way for enhanced global adoption of microbial fertilizers.

Anurag Yadav, Kusum Yadav

SVOA Microbiology • 2024

As eco-friendly alternative to chemical fertilizers, biofertilizers have gained significance in the quest for sustainable farming. While challenges exist, such as regulatory hurdles and technical complexities, the opportunities in this field are substantial. Understanding rhizosphere engineering can enhance biofertilizers' efficiency, ensuring they provide maximum crop benefits. Genetic engineering of bioinoculants offers a pathway to tailor biofertilizers to specific crop needs, potentially increasing their effectiveness. Multi-trait, multi-strain, and multi-nutrient microbial formulations have the potential to revolutionize the biofertilizer market, allowing for customized solutions that address a range of agricultural needs. These innovations are complemented by market dynamics and the integration of nanotechnology, which can further enhance biofertilizer performance and reach. Such opportunities indicate a bright future for biofertilizer commercialization, where sustainable agriculture can benefit from advanced formulations with an improved understanding of soil-plant interactions. Biofertilizers' prospects are promising, offering a more sustainable and environmentally friendly approach to nourishing the world's growing population.

Pema Lhamo, S. Behera, B. Mahanty

Biotechnology Journal • 2021

Microbial polyhydroxyalkanoates (PHAs) produced using renewable resources could be the best alternative for conventional plastics. Despite their incredible potential, commercial production of PHAs remains very low. Nevertheless, sincere attempts have been made by researchers to improve the yield and economic viability of PHA production by utilizing low‐cost agricultural or industrial wastes. In this context, the use of efficient microbial culture or consortia, adoption of experimental design to trace ideal growth conditions, nutritional requirements, and intervention of metabolic engineering tools have gained significant attention.

Hari Koneru, Safiatou Bamba, Aksel Bell et al.

Frontiers in Microbiology • 0

<jats:p>Microalgae are increasingly recognized for their potential in wastewater treatment and the sustainable production of feedstock for fuel, feed, food, and other bioproducts. Like conventional agricultural systems, algal cultivation involves complex microbial communities. However, despite their pivotal role in cultivation outcomes, especially at the commodity-scale, the critical interactions between microalgae and their microbiomes are often overlooked. Here we synthesize current knowledge on the taxonomic diversity, ecological roles, and biotechnological potential of algal microbiomes, with a focus on their interactions with algal hosts through nutrient exchange, growth modulation, pathogen defense, and environmental conditioning. We also examine how environmental factors such as nutrient availability, salinity, and temperature influence these interactions. Advances in microbiome engineering, including synthetic biology and ecological approaches, offer opportunities to enhance beneficial algal-microbiome interactions, thereby improving growth, resilience, and yield. These advancements could lead to more sustainable and economically viable microalgae cultivation, with far-reaching implications for environmental management and biotechnological innovation. By addressing key economic and environmental barriers, microbiome engineering holds transformative potential to revolutionize large-scale algae cultivation and provide sustainable solutions to global challenges.</jats:p>

Di Min, Lei Cheng, Feng Zhang et al.

Environmental Science &amp; Technology • 2017

Dissimilatory metal reducing bacteria (DMRB) are capable of extracellular electron transfer (EET) to insoluble metal oxides, which are used as external electron acceptors by DMRB for their anaerobic respiration. The EET process has important contribution to environmental remediation mineral cycling, and bioelectrochemical systems. However, the low EET efficiency remains to be one of the major bottlenecks for its practical applications for pollutant degradation. In this work, Shewanella oneidensis MR-1, a model DMRB, was used to examine the feasibility of enhancing the EET and its biodegradation capacity through genetic engineering. A flavin biosynthesis gene cluster ribD-ribC-ribBA-ribE and metal-reducing conduit biosynthesis gene cluster mtrC-mtrA-mtrB were coexpressed in S. oneidensis MR-1. Compared to the control strain, the engineered strain was found to exhibit an improved EET capacity in microbial fuel cells and potentiostat-controlled electrochemical cells, with an increase in maximum current density by approximate 110% and 87%, respectively. The electrochemical impedance spectroscopy (EIS) analysis showed that the current increase correlated with the lower interfacial charge-transfer resistance of the engineered strain. Meanwhile, a three times more rapid removal rate of methyl orange by the engineered strain confirmed the improvement of its EET and biodegradation ability. Our results demonstrate that coupling of improved synthesis of mediators and metal-reducing conduits could be an efficient strategy to enhance EET in S. oneidensis MR-1, which is essential to the applications of DMRB for environmental remediation, wastewater treatment, and bioenergy recovery from wastes.

M. Angelaalincy, R. Navanietha Krishnaraj, Ganeshan Shakambari et al.

Frontiers in Energy Research • 2018

Microbial fuel cells (MFCs) are emerging as a promising future technology for a wide range of applications such as bioremediation, desalination, production of biofuels/value-added products in addition to sustainable electricity generation. Electroactive (EA) biofilms are the key players in any bioelectrochemical systems including MFCs. They are involved in the catalyzing oxidation/reduction reactions as well as mediating the electron transfer at electrode-electrolyte interfaces. Low power output of the MFCs remains a major limitation in MFCs and biofilm engineering is an ideal option for improving the rates of microbial electrocatalysis. Herein, we critically address the biofilm formation mechanisms in electroactive microorganisms, strategies for improving the biofilm formation leading to improved electrocatalytic rates for applications in bioelectrochemical systems.

A. Ayol, L. Peixoto, T. Keskin et al.

International Journal of Environmental Research and Public Health • 2021

Microbial C1 gas conversion technologies have developed into a potentially promising technology for converting waste gases (CO2, CO) into chemicals, fuels, and other materials. However, the mass transfer constraint of these poorly soluble substrates to microorganisms is an important challenge to maximize the efficiencies of the processes. These technologies have attracted significant scientific interest in recent years, and many reactor designs have been explored. Syngas fermentation and hydrogenotrophic methanation use molecular hydrogen as an electron donor. Furthermore, the sequestration of CO2 and the generation of valuable chemicals through the application of a biocathode in bioelectrochemical cells have been evaluated for their great potential to contribute to sustainability. Through a process termed microbial chain elongation, the product portfolio from C1 gas conversion may be expanded further by carefully driving microorganisms to perform acetogenesis, solventogenesis, and reverse β-oxidation. The purpose of this review is to provide an overview of the various kinds of bioreactors that are employed in these microbial C1 conversion processes.

Oluwadamilola Oluwatoyin Hazzan, Biyi Zhao, Yong Xiao

Applied Sciences • 2023

Extracellular electron transfer (EET) is a biological mechanism that plays a crucial role in various bioelectrochemical systems (BESs) and has substantial implications for renewable energy production. By utilizing the metabolic capacities of exoelectrogens, BESs offer a viable and environmentally friendly approach to electricity generation and chemical production; however, the diminished effectiveness of EET remains a hindrance to their optimal application in practical contexts. This paper examines the various strategies that have the potential to be employed to enhance the efficiency of EET systems and explores the potential for the integration of BESs technology with contemporary technologies, resulting in the development of an enhanced and sustainable system. It also examines how quorum sensing, electrode modifications, electron shuttles, and mediators can aid in improving EET performance. Many technological innovations, such as additive manufacturing, the science of nanotechnology, the technique of genetic engineering, computational intelligence, and other combinations of technologies that can be used to augment the efficacy of BESs are also discussed. Our findings will help readers understand how BESs, though an evolving technology, can play an important role in addressing our environmental concerns. Technical constraints are identified, and future directions in the field of EET are suggested.

Yan Tian, Jing Wu, Dandan Liang et al.

Environmental Science &amp; Technology • 2023

Bioelectrochemical-based biogas upgrading is a promising technology for the storage of renewable energy and reduction of the global greenhouse gas emissions. Understanding the electron transfer behavior between the electrodes and biofilm is crucial for the development of this technology. Herein, the electron transfer pathway of the biofilm and its catalytic capability that responded to the cathode potential during the electromethanogenesis process were investigated. The result suggested that the dominant electron transfer pathway shifted from a direct (DET) to indirect (IDET) way when decreasing the cathode potential from -0.8 V (Bio-0.8 V) to -1.0 V (Bio-1.0 V) referred to Ag/AgCl. More IDET-related redox substances and high content of hydrogenotrophic methanogens (91.9%) were observed at Bio-1.0 V, while more DET-related redox substances and methanogens (82.3%) were detected at Bio-0.8 V. H2, as an important electron mediator, contributed to the electromethanogenesis up to 72.9% of total CH4 yield at Bio-1.0 V but only ∼17.3% at Bio-0.8 V. Much higher biogas upgrading performance in terms of CH4 production rate, final CH4 content, and carbon conversion rate was obtained with Bio-1.0 V. This study provides insight into the electron transfer pathway in the mixed culture constructed biofilm for biogas upgrading.

Nils Rohbohm, Tianran Sun, Ramiro Blasco-Gómez et al.

• 2023

Microbial electrosynthesis is an emerging biosynthesis technology that produces value-added chemicals and fuels and, at the same time, reduces the environmental carbon footprint. However, constraints, such as low current densities and high inner resistance, disfavor this technology for industrial-scale purposes. The cathode performance has been strongly improved in recent years, while the anode performance has not been given enough attention despite its importance in closing the electric circuit. For traditional water electrolysis, O2 is produced at the anode, which is toxic to the anaerobic autotrophs that engage in microbial electrosynthesis. To overcome O2 toxicity in conventional microbial electrosynthesis, the anode and the cathode chamber have been separated by an ion-exchange membrane to avoid contact between the microbes and O2. However, ion-exchange membranes increase the maintenance costs and compromise the production efficiency by introducing an additional internal resistance. Furthermore, O2 is inevitably transferred to the catholyte due to diffusion and electro-osmotic fluxes that occur within the membrane. Here, we proved the concept of integrating carbon oxidation with sacrificial anodes and microbes to simultaneously inhibit the O2 evolution reaction (OER) and circumvent membrane application, which allows microbial electrosynthesis to proceed in a single chamber. The carbon-based anodes performed carbon oxidation as the alternative reaction to the OER. This enables microbial electrosynthesis to be performed with cell voltages as low as 1.8-2.1 V at 10 A·m-2. We utilized Methanothermobacter thermautotrophicus ΔH in a single-chamber Bioelectrochemical system (BES) with the best performing carbon-based anode (i.e., activated-carbon anode with soluble iron) to achieve a maximum cathode-geometric CH4 production rate of 27.3 L·m-2·d-1, which is equal to a volumetric methane production rate of 0.11 L·L-1·d-1 in our BES, at a coulombic efficiency of 99.4%. In this study, Methanothermobacter thermautotrophicus ΔH was majorly limited by sulfur that inhibited electromethanogenesis. However, this proof-of-concept study allows microbial electrosynthesis to be performed more energy-efficiently and can be immediately utilized for research purposes in microbial electrosynthesis.

Shen Wang, Xinglei Zhuang, W. Dong et al.

Fermentation • 2023

Bioelectrochemical systems (BESs) are an emerging technology for wastewater treatment and resource recovery. These systems facilitate electron transfer between microorganisms and electrodes, enabling their application in various fields, such as electricity production, bioremediation, biosensors, and biocatalysis. However, electrode biofilms, which play a critical role in BESs, face several challenges (e.g., a long acclimation period, low attached biomass, high electron transfer resistance, and poor tolerance and stability) that limit the development of this technology. Quorum sensing (QS) is a communication method among microorganisms that can enhance the performance of BESs by regulating electrode biofilms. QS regulation can positively impact electrode biofilms by enhancing extracellular electron transfer (EET), biofilm formation, cellular activity, the secretion of extracellular polymeric substances (EPS), and the construction of microbial community. In this paper, the characteristics of anode electrogenic biofilms and cathode electrotrophic biofilms in BESs, EET mechanisms, and the main factors affecting biofilm formation were summarized. Additionally, QS regulation mechanisms for biofilm formation, strategies for enhancing and inhibiting QS, and the application of QS regulation for electrode biofilms in BESs were systematically reviewed and discussed. This paper provides valuable background information and insights for future research and development of BES platforms based on QS regulation of electrode biofilms.

Yan Tian, Dandan Liang, Da Li et al.

Environmental Science &amp; Technology • 2023

The metal-based current collector has been adopted as an essential component of cathodes for electron delivery in microbial electrosynthesis (MES) cells, while the effect of its corrosion on biofilm development and electromethanogenesis activity was overlooked. In this study, the corrosion of the Fe-based current collector was identified to in situ decorate cathode naturally which substantially boosted the performance of CO2 electromethanogenesis in terms of taking over two-thirds less time starting up MES and increasing the CH4 production rate by 3.5 times. Despite the low concentration of Fe (0.13 at%), the electrochemical analysis indicated that it was possible for these Fe deposits to act as electron shuttles and catalysts for H2 production to benefit methanogenesis. The Fe aggregates weakened the dependence of methanogens on electroactive bacteria (EABs) to conduct methanogenesis via interspecies electron transfer as the proportion of EABs on Bio FeCF (with Fe current collector, where CF is carbon felt) was only 25.5% of that on Bio CF (without Fe current collector). On the contrary, the abundance of genes encoding the proteins to uptake extracellular electrons of methanogens on Bio FeCF was 2.3 times higher than that on Bio CF. The enhanced energy transfer maintained high amounts of methanogens and live microorganisms. This study comprehensively explored the multiple roles of Fe-based current collectors in enhancing CO2 electromethanogenesis.

Qun Xue, Zhihui Chen, Wenjing Xie et al.

Molecules • 2024

Bioelectrochemical systems (BESs) are an innovative technology for the efficient degradation of antibiotics. Shewanella oneidensis (S. oneidensis) MR-1 plays a pivotal role in degrading sulfamethoxazole (SMX) in BESs. Our study investigated the effect of BES conditions on SMX degradation, focusing on microbial activity. The results revealed that BESs operating with a 0.05 M electrolyte concentration and 2 mA/cm2 current density outperformed electrolysis cells (ECs). Additionally, higher electrolyte concentrations and elevated current density reduced SMX degradation efficiency. The presence of nutrients had minimal effect on the growth of S. oneidensis MR-1 in BESs; it indicates that S. oneidensis MR-1 can degrade SMX without nutrients in a short period of time. We also highlighted the significance of mass transfer between the cathode and anode. Limiting mass transfer at a 10 cm electrode distance enhanced S. oneidensis MR-1 activity and BES performance. In summary, this study reveals the complex interaction of factors affecting the efficiency of BES degradation of antibiotics and provides support for environmental pollution control.