Enzyme and Microbial Technology最新文献

{"title":"Genetic Engineering of Yarrowia lipolytica for 1,8-cineole production: A sustainable approach","authors":"Krutika Bhoir,&nbsp;Gunjan Prakash,&nbsp;Annamma Odaneth","doi":"10.1016/j.enzmictec.2025.110659","DOIUrl":"10.1016/j.enzmictec.2025.110659","url":null,"abstract":"<div><div>1,8-Cineole, a monoterpene with diverse industrial and pharmaceutical applications, has garnered significant interest due to its unique properties. This study aims to achieve sustainable production of 1,8-cineole from <em>Yarrowia lipolytica</em> through metabolic and media engineering strategies. The heterologous 1,8-cineole synthase from <em>Streptomyces clavuligerus</em> was integrated through CRISPR-Cas9, along with overexpression of key genes in the mevalonate pathway and a double mutation in the Erg20p to enhance flux towards geranyl pyrophosphate. The modified strain was further investigated for varying carbon and nitrogen sources with MgSO₄ addition. The above approaches achieved a titer of 4.68 mg/L of 1,8-cineole along with 1108.53 mg/L of intracellular squalene when grown on 5 % WCO, marking the first report of genetic engineering of <em>Y. lipolytica</em> for 1,8-cineole production. Further studies are in progress to redirect internal fluxes to 1,8-cineole for improvising yields and productivities. This work shows a sustainable and innovative approach to biotechnology improvements in terpene biosynthesis and waste valorization.</div></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"189 ","pages":"Article 110659"},"PeriodicalIF":3.4,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Functional analysis of cytochrome P450 monooxygenases from the white-rot basidiomycete Trametes versicolor: CYP502B15 decorates cadinane-type sesquiterpenoids","authors":"Hirofumi Ichinose,&nbsp;Megumu Honda ,&nbsp;Tsuyoshi Isogai ,&nbsp;Chen Chen ,&nbsp;Takuya Kitaoka","doi":"10.1016/j.enzmictec.2025.110658","DOIUrl":"10.1016/j.enzmictec.2025.110658","url":null,"abstract":"<div><div>Cytochrome P450 monooxygenases (P450) play crucial roles in the diversification of secondary metabolic systems in living organisms. Basidiomycetes produce a wide variety of natural products as secondary metabolites, with their relevance to pharmaceutical and agricultural applications garnering significant interest. Thus, the functional characterization of fungal P450s is essential for basic and applied research of basidiomycetes. We herein describe the identification and functional characterization of P450 in the white-rot basidiomycete <em>Trametes versicolor</em> (TvCYP)<em>.</em> A total of 182 TvCYP genes were identified in the <em>T. versicolor</em> genome. Moreover, 145 cDNAs encoding possible mature open reading frames were isolated/generated. Furthermore, we constructed a library of TvCYPs using a yeast expression system that allowed for the semi-comprehensive screening of latent TvCYP functions. Notably, we used this library to identify TvCYPs responsible for the metabolism of cadinane-type sesquiterpenoids. CYP502B15 was revealed to have significant activities against γ-cadinene and epicubenol. On the basis of NMR and X-ray crystal structure experiments, CYP502B15 was observed to catalyze the 3α-hydroxylation of γ-cadinene and epicubenol. To the best of our knowledge, this is the first report of the identification of basidiomycetous P450s responsible for the metabolism of cadinane-type sesquiterpenoids.</div></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"189 ","pages":"Article 110658"},"PeriodicalIF":3.4,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143867665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fungal tyrosinase immobilized on chitosan, calcium alginate, and silica gel for phenol elimination and dye decolorization","authors":"Hamed M. El-Shora ,&nbsp;Nahla T. Elazab ,&nbsp;Abdulaziz Al-Anazi ,&nbsp;Gharieb S. El-Sayyad ,&nbsp;Mohsen E. Ibrahim ,&nbsp;Mohammad W. Alfakharany","doi":"10.1016/j.enzmictec.2025.110655","DOIUrl":"10.1016/j.enzmictec.2025.110655","url":null,"abstract":"<div><div><em>Aspergillus nidulans</em> (AUMC No. 7147) was utilized for tyrosinase (EC 1.14.18.1) production. In this study, we purified the enzyme, immobilized it on various beads, analyzed its kinetics, and applied it for phenol removal and dye decolorization, including Crystal Violet (CV), Congo Red (CR), Methyl Red (MR), and Malachite Green (MG). Tyrosinase was isolated from <em>Aspergillus nidulans</em> (AUMC No. 7147) with a specific activity of 230.76 units mg⁻¹ protein. The purified enzyme was then immobilized on chitosan, Ca-alginate, and silica gel, achieving immobilization efficiencies of 89.6 %, 75.0 %, and 69.4 %, respectively. After 10 reuse cycles, the immobilized tyrosinase on chitosan and Ca-alginate retained 41 % and 15 % of its initial activity, respectively. The K_m values were determined to be 0.23, 0.37, and 0.38 mM, while the V_max values were 32.5, 33.3-, and 27.5-units mg⁻¹ protein for the free enzyme and the two immobilized forms, respectively. After 30 days of storage at 25°C, the residual activities of tyrosinase immobilized on silica gel, alginate, and chitosan were 14 %, 27 %, and 52 %, respectively. The optimal temperatures for the free and immobilized tyrosinase were 40°C and 50°C, respectively. The activation energies were calculated as 59.66, 54.43, and 48.86 KJ mol⁻¹ . The free tyrosinase exhibited an optimal pH of 7.0, which shifted to pH 8.0 upon immobilization. The enzyme could be reused for at least eight cycles. Phenol was effectively removed by chitosan-immobilized tyrosinase; however, the removal efficiency declined in subsequent cycles. The highest removal percentage was achieved using the chitosan-immobilized enzyme at pH 8.0, and Temp., 50°C, after 2 hours. Additionally, the immobilized enzyme was effective in decolorizing the dyes Crystal Violet (CV), Congo Red (CR), Methyl Red (MR), and Malachite Green (MG). These findings support bioremediation strategies for the safe environmental removal of toxic dyes, and phenol from wastewater.</div></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"189 ","pages":"Article 110655"},"PeriodicalIF":3.4,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143851998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comprehensive insights into carbonic anhydrase inhibition: A triad of In vitro, In silico, and In vivo perspectives","authors":"Ahmed A. Allam ,&nbsp;Hassan A. Rudayni ,&nbsp;Noha A. Ahmed ,&nbsp;Faris F. Aba Alkhayl ,&nbsp;Al Mokhtar Lamsabhi ,&nbsp;Emadeldin M. Kamel","doi":"10.1016/j.enzmictec.2025.110657","DOIUrl":"10.1016/j.enzmictec.2025.110657","url":null,"abstract":"<div><div>Carbonic anhydrases (CAs) are zinc-dependent metalloenzymes essential for sustaining physiological balance by facilitating the reversible conversion of carbon dioxide to its hydrated form. Their biological significance, coupled with their involvement in a wide array of pathological conditions, makes them attractive targets for therapeutic intervention. This review presents a comprehensive analysis of carbonic anhydrase inhibition through an integrated triad of <em>in vitro</em>, <em>In silico</em>, and <em>In vivo</em> perspectives. <em>In vitro</em> studies provide critical insights into the mechanisms of enzyme inhibition, enabling the identification and optimization of potent inhibitors while elucidating their structure-activity relationships. <em>In silico</em> methodologies, including docking, molecular dynamics (MD) simulation, virtual screening, ADMET, and QSAR analyses, have emerged as invaluable tools in rational drug design, streamlining the discovery and development of isoform-specific inhibitors. Complementing these efforts, <em>In vivo</em> investigations validate the pharmacokinetics, pharmacodynamics, and therapeutic efficacy of CA inhibitors (CAIs) in disease models, bridging the gap between laboratory findings and clinical applications. The therapeutic relevance of CAIs extends across multiple domains, including glaucoma, epilepsy, cancer, metabolic disorders, and infectious diseases. Emerging applications, such as their potential use in combating antimicrobial resistance and modulating immune responses, further underscore their versatility. However, challenges such as achieving isoform selectivity, minimizing off-target effects, and translating preclinical findings into clinical success persist. Advances in fragment-based drug design, artificial intelligence-driven discovery, and innovative experimental techniques are poised to address these limitations, paving the way for the next generation of CAIs.</div></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"189 ","pages":"Article 110657"},"PeriodicalIF":3.4,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143845267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biochemical and structural characterization of a family-9 glycoside hydrolase bioprospected from the termite Syntermes wheeleri gut bacteria metagenome","authors":"Raul Alcântara Teixeira Lima ,&nbsp;Aisel Valle Garay ,&nbsp;Tayná Diniz Frederico ,&nbsp;Gideane Mendes de Oliveira ,&nbsp;Betania Ferraz Quirino ,&nbsp;João Alexandre Ribeiro Gonçalves Barbosa ,&nbsp;Sonia Maria de Freitas ,&nbsp;Ricardo Henrique Krüger","doi":"10.1016/j.enzmictec.2025.110654","DOIUrl":"10.1016/j.enzmictec.2025.110654","url":null,"abstract":"<div><div>Glycosyl hydrolases (GH) are enzymes involved in the degradation of plant biomass. They are important for biorefineries that aim at the sustainable utilization of lignocellulosic residues to generate value-added products. The termite <em>Syntermes wheeleri</em> gut microbiota showed an abundance of bacteria from the phylum Firmicutes, a phylum with enzymes capable of breaking down cellulose and degrading lignin, facilitating the use of plant materials as a food source for termites. Using bioinformatics techniques, cellobiohydrolases were searched for in the gut metagenome of the termite <em>Syntermes wheeleri</em>, endemic to the Cerrado. After selecting sequences of the target enzymes, termite gut microbiome metatranscriptome data were used as the criteria to choose the GH9 enzyme sequence Exo8574. Here we present the biochemical and structural characterization of Exo8574, a GH9 enzyme that showed activity with the substrate p-nitrophenyl-D-cellobioside (pNPC), consistent with cellobiohydrolase activity. Bioinformatics tools were used to perform phylogeny studies of Exo8574 and to identify conserved families and domains. Exo8574 showed 48.8 % homology to a protein from a bacterium belonging to the phylum Firmicutes. The high-quality three-dimensional (3D) model of Exo8574 was obtained by protein structure prediction AlphaFold 2, a neural network-based method. After the heterologous expression of Exo8574 and its purification, biochemical experiments showed that the optimal activity of the enzyme was at a temperature of 55 ºC and pH 6.0, which was enhanced in the presence of metal ions, especially Fe^2 +. The estimated kinetic parameters of Exo8574 using the synthetic substrate p-nithrophenyl-beta-D-cellobioside (pNPC) were: V_max = 9.14 ± 0.2 x10⁻⁵ μmol/min and <em>K</em>_m = 248.27 ± 26.35 μmol/L. The thermostability test showed a 50 % loss of activity after 1 h incubation at 55 °C. The secondary structure contents of Exo8574 evaluated by Circular Dichroism were pH dependent, with greater structuring of protein in β-antiparallel and α-helices at pH 6.0. The similarity between the CD results and the Ramachandran plot of the 3D model suggests that a reliable model has been obtained. Altogether, the results of the biochemical and structural characterization showed that Exo8574 is capable of acting on p-nithrophenyl-beta-D-cellobioside (pNPC), a substrate that mimics bonds cleaved by cellobiohydrolases. These findings have significant implications for advancing in the field of biomass conversion while also contributing to efforts aimed at overcoming challenges in developing more efficient cellulase cocktails.</div></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"189 ","pages":"Article 110654"},"PeriodicalIF":3.4,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143851999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rhamnosyltransferases: Biochemical activities, potential biotechnology for production of natural products and their applications","authors":"Nguyen Huy Thuan ,&nbsp;Bui Dinh Lam ,&nbsp;Nguyen Thanh Trung","doi":"10.1016/j.enzmictec.2025.110656","DOIUrl":"10.1016/j.enzmictec.2025.110656","url":null,"abstract":"<div><div>Rhamnosyltransferase is an enzyme that catalyzes the transfer of rhamnose moieties from an activated donor molecule, typically nucleotide diphosphate-rhamnose (NDP-rhamnose), to a wide range of acceptor molecules, including proteins, lipids, saccharides, glycoproteins, glycans, and glycolipids. This enzymatic process, known as rhamnosylation, plays a fundamental role in the biosynthesis of critical biomolecules, such as components of the cell wall, plasma membrane channels, receptors, antigens, signaling molecules, antibiotics, and other secondary metabolites. Due to its essential involvement in both primary and secondary metabolic pathways, rhamnosyltransferase is indispensable for various biological processes and exhibits significant potential for applications in human health and industrial biotechnology. In recent years, this enzyme has garnered substantial attention from the scientific community, owing to its unique biochemical properties and its utility in diverse sectors, including medicine, food technology, and cosmetics. This review aims to synthesize recent advancements in the study of rhamnosyltransferase, with a focus on its catalytic mechanisms, biological significance, and emerging applications in biotechnological innovation.</div></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"189 ","pages":"Article 110656"},"PeriodicalIF":3.4,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143828747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A lateral flow biosensor based on duplex-specific nuclease and novel isothermal amplification for detection of influenza virus","authors":"Xiaoying Zhang ,&nbsp;Qianyu Zhou ,&nbsp;Shengjun Bu ,&nbsp;Yuqi Yang ,&nbsp;Lingling Wang ,&nbsp;Chuanna Xu ,&nbsp;Zhuo Hao ,&nbsp;Guijuan Qu ,&nbsp;Jiayu Wan","doi":"10.1016/j.enzmictec.2025.110653","DOIUrl":"10.1016/j.enzmictec.2025.110653","url":null,"abstract":"<div><div>Here, we describe a lateral flow biosensor capable of detecting H1N1 virus by integrating duplex-specific nuclease (DSN) and a novel isothermal amplification, two probe isothermal amplification (TPIA). Probe A and probe B of TPIA form DNAs of varying lengths by repeated polymerization and displacement of each other. Probe A extends into single-stranded DNA (ssDNA) of varying lengths containing multiple hairpin structures. Probe B extends into double-stranded DNA hairpins of different lengths. Both the 5′ end of the single strand DNA (ssDNA) probe A and probe B were joined by a ssDNA tail via a C3 spacer. These tails were designed to be complementary to capture sequence of probe C (5 'end modifies fluorescein [FAM]) immobilized on magnetic beads. Cyclical DSN cleavage of probe C was triggered by target H1N1 RNA to release a capture sequence to capture TPIA product DNA with multiple biotins. The TPIA product/capture sequence complex of FAM can be captured by anti-FAM in the test strip test area, and the accumulation of gold nanoparticles causes a red band to appear in the test area. The limit of detection of specific RNA was as low as 829 fM with a linear range from 1 pM to 100 nM. This visual detection system is suitable for influenza A H1N1 virus point-of-care diagnosis in non-specialist personnel and low-resource settings.</div></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"188 ","pages":"Article 110653"},"PeriodicalIF":3.4,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143808019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advances in engineering and applications of microbial glutamate decarboxylases for gamma-aminobutyric acid production","authors":"Yuanrong Lu ,&nbsp;Feng Zhang ,&nbsp;Leli Wang ,&nbsp;Zhide Tian ,&nbsp;Yaojun Li ,&nbsp;Zhouyang Li ,&nbsp;Jingbai Wen","doi":"10.1016/j.enzmictec.2025.110652","DOIUrl":"10.1016/j.enzmictec.2025.110652","url":null,"abstract":"<div><div>Gamma-aminobutyric acid (GABA) is a key neurotransmitter with significant health benefits, including anxiolytic and anti-hypertensive effects, and potential use in biodegradable material synthesis. The increasing market demand for GABA has intensified the search for cost-effective production methods. The key enzyme involved in GABA production is glutamate decarboxylase (GAD), which catalyzes the conversion of L-glutamate to GABA. GAD plays a central role in various production approaches, such as enzyme-based catalysis, whole-cell catalysis, and microbial fermentation. Although microbial GADs are preferred for their high catalytic activity, their low pH and thermal stability present significant challenges for large-scale GABA production. Wild-type GADs typically have an optimal pH range of 4–5, and their activity sharply declines as the pH increases, thereby reducing production efficiency. Furthermore, GADs' poor thermal stability makes them vulnerable to temperature fluctuations during industrial processes, further limiting GABA production. Recent research has focused on engineering GAD variants with improved stability and performance through rational design, directed evolution, and semi rational approaches. These advancements not only expand the potential applications of GAD in biocatalysis but also offer promising solutions for sustainable GABA production. This paper provides an in-depth review of the engineering of GADs, applications of GAD in GABA production, and strategies to overcome limitations, offering a comprehensive overview of the current state and future prospects of GAD modification in enhancing GABA production.</div></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"188 ","pages":"Article 110652"},"PeriodicalIF":3.4,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143791679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancement of the start-up and performance of an upflow anaerobic sludge blanket (UASB) reactor using electrochemically-enriched biofilm","authors":"Mohamad Abdallah ,&nbsp;Stephanie Greige ,&nbsp;Christina F. Webster ,&nbsp;Moustapha Harb ,&nbsp;Haluk Beyenal ,&nbsp;Mahmoud Wazne","doi":"10.1016/j.enzmictec.2025.110651","DOIUrl":"10.1016/j.enzmictec.2025.110651","url":null,"abstract":"<div><div>A novel approach was developed to accelerate the start-up of a 20-L UASB reactor under mesophilic conditions. Two runs were conducted, where the first run (Run I) was inoculated with anaerobic sludge, and the second run (Run II) was inoculated with the same sludge supplemented with enriched electro-active biofilms collected from the working and counter electrodes of anodic and cathodic bio-electrochemical systems (BESs). Reactors’ performance and microbial dynamics were monitored over 41 days. Methane production in Run II exceeded 200 mL-CH₄/g-COD within 10 days, compared to 29 days in Run I. Run II achieved 80 % removal of soluble COD after 13 days as compared to 23 days in Run I. Sludge washout in Run II stabilized after 3 days, achieving 70 % VSS removal, whereas Run I required 17 days. Greater extracellular polymeric substance (EPS) values and higher protein-to-polysaccharide ratios in Run II may indicate accelerated granules formation mediated by EPS. 16S rRNA gene sequencing analysis results revealed shared genera between both runs but different relative abundances. <em>Methanothrix</em> dominated in Run I, while other archaeal genera, mainly <em>Methanosarcina</em> and <em>Methanobacterium</em> increased in abundance in the Run II. The <em>Enterobacteriaceae</em> family was prevalent in both reactors, with three genera, <em>Citrobacter</em>, <em>Klebsiella</em>, and <em>Enterobacter</em> distinctly dominating at different time points, suggesting potential links with the initial seed sludge or enriched biofilm consortia. The addition of electrochemically grown biofilm in Run II likely enhanced the microbial diversity, contributed to the rapid development of granular syntrophic communities, and improved reactor performance.</div></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"188 ","pages":"Article 110651"},"PeriodicalIF":3.4,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143808020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microbial community analysis of the biofilms of both working and counter electrodes in single-chamber microbial electrolysis cells","authors":"Stephanie Greige ,&nbsp;Mohamad Abdallah ,&nbsp;Christina F. Webster ,&nbsp;Moustapha Harb ,&nbsp;Haluk Beyenal ,&nbsp;Mahmoud Wazne","doi":"10.1016/j.enzmictec.2025.110650","DOIUrl":"10.1016/j.enzmictec.2025.110650","url":null,"abstract":"<div><div>This study was conducted to delineate microbial community development and composition on both working and counter electrodes in single-chamber microbial electrolysis cells (MECs) using synthetic wastewater. Two separate bioelectrochemical reactors were inoculated with anaerobic sludge. The first was operated at an anodic potential poised at + 0.4 V and the second one at a cathodic potential poised at −0.7 V, both vs. an Ag/AgCl reference electrode. The performance of the MECs, including current generation, bioelectrochemical activity of the biofilms on both the working and counter electrodes, and chemical oxygen demand (COD) depletion were monitored over the last 45 days of operation. Scanning electron microscopy (SEM) and 16S rRNA gene sequencing were performed to delineate the development and morphology of the microbial communities on both the working and the counter electrodes. The current generated at the anodic working electrode provided evidence of the growth of anode-respiring exoelectrogens (<em>Clostridium sensu stricto</em>). Similarly, the Faradaic current data at the cathodic working electrode confirmed the formation of an electroactive biofilm dominated by acetoclastic and hydrogenotrophic methanogens (<em>Methanothrix</em> and <em>Methanobacterium</em>). Microbial communities on the counter electrodes were found to be richer but less diverse compared to those on the working electrodes. These communities were likely influenced by the fluctuating potentials at the counter electrodes. SEM observations were consistent with the microbial analysis. These findings demonstrate the ability of a mixed inoculum to shift towards anode-reducing and cathode methanogenic communities using a complex substrate on a constant working electrode and varying counter electrode potentials.</div></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"188 ","pages":"Article 110650"},"PeriodicalIF":3.4,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143808021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}