Biotechnology for Biofuels最新文献

{"title":"Improving silage fermentation of distilled grain waste-based spent mushroom substrate using indigenous lactic acid bacteria: metagenomic insights","authors":"Xinlei Zhang,&nbsp;Diao Yin,&nbsp;Pengyu Liu,&nbsp;Jialun Song,&nbsp;Zemin Fang,&nbsp;Juanjuan Liu","doi":"10.1186/s13068-026-02803-0","DOIUrl":"10.1186/s13068-026-02803-0","url":null,"abstract":"<div><h3>Background</h3><p>Rising global mushroom production calls for recycling spent mushroom substrate (SMS). However, its high moisture content, susceptibility to spoilage, and low abundance of indigenous lactic acid bacteria (LAB) limit its use as silage. In this study, an effective silage inoculation strategy was developed to transform SMS derived from composted distilled grain waste (DGW) and colonized by <i>Pleurotus ostreatus</i>.</p><h3>Results</h3><p>Three indigenous lactic acid bacteria, including <i>Limosilactobacillus fermentum</i> L2, <i>Weissella paramesenteroides</i> W1, and <i>Pediococcus acidilactici</i> P1, were isolated and selected for their rapid growth and acidification capacity, and applied individually or in combination at different stages of fungal colonization. Compared with a commercial inoculant, all indigenous lactic acid bacteria (LAB) treatments, especially a combination of <i>L. fermentum</i> L2 and <i>P. acidilactici</i> P1, significantly enhanced silage fermentation, as evidenced by lower pH (4.04–4.73), 31-fold and 1.87-fold increases in lactic acid and acetic acid production, respectively, improved crude protein retention, and preserved dry matter contents. KEGG enrichment analysis demonstrated that carbon metabolic flux was markedly redirected toward lactic acid fermentation, while pathways related to protein degradation and biosafety were significantly suppressed in LAB-treated SMS silage. Weighted metabolic analysis revealed that LAB contributed most to fermentative processes, thereby enriching <i>Pediococcus</i>, <i>Weissella</i>, and <i>Lactobacillus</i>, whereas the contributions of non-LAB and potentially harmful microorganisms were substantially reduced.</p><h3>Conclusion</h3><p>These results indicate that indigenous LAB enhance the ensiling efficiency of SMS by driving functional reallocation and pathway-level dominance, thereby improving fermentation efficiency, stability, and nutritional quality, highlighting their potential for promoting SMS silage as a high-quality ruminant feed resource.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13715123/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149290653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Host-dependent activities of prenyltransferases in yeast and tobacco for cell-free cannflavin biosynthesis","authors":"Sung-eun Lee,&nbsp;Saet Buyl Lee,&nbsp;Hyun Ju Jung,&nbsp;Ji-Su Kim,&nbsp;Hyoseon Choi,&nbsp;Sangchul Choi,&nbsp;Beom-Gi Kim","doi":"10.1186/s13068-026-02800-3","DOIUrl":"10.1186/s13068-026-02800-3","url":null,"abstract":"<div><p>Cannflavins are prenylated flavones found in <i>Cannabis sativa</i> that exhibit potent anti-inflammatory activities, but their low natural abundance limits pharmacological exploitation. Biotechnological strategies are therefore needed to support cannflavin production. Here, we evaluated yeast (<i>Saccharomyces cerevisiae</i>) and <i>Nicotiana benthamiana</i> as heterologous platforms for cell-free cannflavin biosynthesis. Six plant- and microbe-derived prenyltransferases (PTs) were expressed in both hosts and assessed for apparent cannflavin-forming activity using cell-free enzyme assays. In yeast-derived microsomal assays, CsPT3 from <i>C. sativa</i> produced cannflavin A (CFL-A) and cannflavin B (CFL-B), and removal of its predicted N-terminal transit peptide enhanced apparent CFL-A and CFL-B formation. By contrast, CsPT3 and cytCsPT3 did not produce detectable cannflavins in <i>N. benthamiana</i>-derived crude extract assays. Instead, the soluble microbial PT NphB supported CFL-A formation in <i>N. benthamiana</i>-derived enzyme preparations. We further established a crude extract-based one-pot assay in <i>N. benthamiana</i> and examined the effects of codon optimization of NphB, assay pH, and <i>Agrobacterium</i> inoculum density on apparent CFL-A formation. These results demonstrate that cannflavin-forming PT activity is highly dependent on host context and expression conditions. This comparative cell-free approach identifies suitable enzyme–host combinations for cannflavin biosynthesis and provides a practical platform for screening and improving prenylated flavonoid production.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13700126/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149278643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Methane production from the co-digestion of banana crop residues and the organic fraction of municipal solid waste: influence of steam explosion","authors":"Diana Marcela Durán Hernández,&nbsp;Juan Luis Ramos-Suárez,&nbsp;Nely Carreras,&nbsp;Zulma Lorena Durán Hernández,&nbsp;Mario Enrique Velásquez Lozano","doi":"10.1186/s13068-026-02794-y","DOIUrl":"10.1186/s13068-026-02794-y","url":null,"abstract":"<div><h3>Background</h3><p>Anaerobic digestion of residual biomass is of great interest due to its contribution to the circular economy and the reduction of greenhouse gas emissions. The biogas sector is focused on the identification of new feedstocks and the application of innovative technologies to improve biogas production and process efficiency. Colombia is one of the major banana producers and exporters worldwide, generating large amounts of agricultural waste. This study investigates the use of banana crop residues (BCR), specifically rachis (R) and pseudostem (P), and their co-digestion with the organic fraction of municipal solid waste (OFMSW) in the anaerobic digestion process.</p><h3>Results</h3><p>Due to their high lignocellulose content, BCR were pretreated by steam explosion (SE). R was pretreated at 180 and 200 °C for 10 min, while P was pretreated at 160 and 180 °C for 10 min. Biochemical methane potential (BMP) tests showed methane yields of 534.5, 363.3 and 202.2 L_CH4/kg_VS (on a volatile solids (VS) basis) for OFMSW, raw P and raw R, respectively. SE pretreatment increased biodegradability and methane yield in co-digestion assays. SE at 180 ºC for P (P180) and R (R180) increased biodegradability by 25% in a mixture composed of OFMSW, P and R (70%, 20% and 2% on a VS basis, respectively). This mixture (OFMSW-P180-R180) exhibited the highest methane yield, with 457.5 L_CH4/kg_VS, equivalent to 201.85 kWh_e/t of wet biomass.</p><h3>Conclusions</h3><p>The results demonstrate that SE pretreatment, when applied within an optimal severity window, enhances the synergistic co-digestion of lignocellulosic agricultural residues with urban organic waste. This integrated approach demonstrates promising potential as a technically viable strategy, under controlled laboratory BMP conditions, to improve methane production and supports the development of circular bioeconomy systems in regions with high availability of both waste streams. Nevertheless, the methane yields reported in this study correspond to laboratory-scale BMP assays under optimized batch conditions and should therefore be interpreted as maximum biomethane potentials rather than direct industrial-scale performance values.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s13068-026-02794-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149339232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Formate-driven in situ CO2 recycling for efficient succinic acid bioproduction in engineered Actinobacillus succinogenes","authors":"Mingyang Zhao,&nbsp;Li Wang,&nbsp;Yuanming Ye,&nbsp;Yaqin Sun,&nbsp;Zhilong Xiu","doi":"10.1186/s13068-026-02799-7","DOIUrl":"10.1186/s13068-026-02799-7","url":null,"abstract":"<div><h3>Background</h3><p>Succinic acid (SA) biosynthesis presents a promising sustainable alternative to petrochemical routes, yet industrial potential is often hampered by inefficient CO₂ fixation and redox imbalances.</p><h3>Results</h3><p>To systematically address these bottlenecks, a synergistic metabolic engineering strategy was developed in <i>Actinobacillus succinogenes</i> by co-expressing the endogenous gene of formate dehydrogenase (FdoG) and the heterologous gene of phosphoenolpyruvate carboxylase (PPC). This design established a self-reinforcing metabolic loop where FdoG-mediated formate oxidation generated in situ CO₂ and NADH, which were immediately channeled into the PPC-driven carboxylation pathway. Physiological characterizations, utilizing real-time off-gas analysis, demonstrated that this pathway effectively functions as an endogenous CO₂ generator, decoupling production from external mass transfer limitations. Furthermore, carbon flux distribution analysis confirmed the synergistic efficacy, revealing a 12.11% increase in succinate-directed flux and a significant reduction in byproduct accumulation compared to the wild type. To fully exploit this formate-utilization potential, an optimized fed-batch fermentation with pulsed formate feeding was implemented. Consequently, the engineered strain AS-PF achieved a remarkable succinate titer of 96.64 g/L, with a productivity of 1.38 g/ (L·h), corresponding to an overall product yield of 0.78 g/g based on the total consumed mixed carbon source (glucose and formate).</p><h3>Conclusion</h3><p>This study establishes a sustainable and efficient platform for SA bioproduction by synergistically integrating formate metabolism-driven CO₂ recycling with enhanced biosynthetic pathways, thereby advancing the valorization of C1 compounds.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s13068-026-02799-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149229260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Valorization of sorghum stalk lignocellulose for xylooligosaccharide production: process optimization and chromatographic characterization","authors":"Nisha Nisha,&nbsp;Sumit Arora,&nbsp;Richa Singh,&nbsp;Ashis Kumar Samanta,&nbsp;Nepolean Thirunavukkarasu,&nbsp;Tara C. Satyavathi,&nbsp;Sachin Kumar","doi":"10.1186/s13068-026-02798-8","DOIUrl":"10.1186/s13068-026-02798-8","url":null,"abstract":"<div><p>Sorghum stalk (<i>Sorghum bicolor</i>) represents an abundant and underutilized lignocellulosic biomass with significant potential for the generation of value-added bioproducts within biorefinery systems. In the present study, sorghum stalk (SS) biomass was valorized for the production of xylooligosaccharides (XOS) through alkaline extraction of xylan, followed by enzymatic hydrolysis. SS was treated with alkali to extract high-purity xylan, where increasing NaOH concentrations significantly (<i>p</i> &lt; 0.05) enhanced xylan recovery. Fourier-transform infrared spectroscopy indicated that xylan extracted using 3 M NaOH contained minimal lignin and represented a higher recovery (87.17 ± 0.32%). Enzymatic hydrolysis of extracted xylan, as optimized using Design-Expert software, resulted in maximum XOS production at pH 5.5, 45.45 °C, 24 h incubation, and an enzyme dose of 20 IU per 200 mg xylan. Analytical characterization revealed that the hydrolysates predominantly contained XOS with a degree of polymerization ranging from 2 to 6, primarily composed of xylohexaose. The produced XOS exhibited promising prebiotic potential for <i>Lactobacillus salivarius</i>, as evidenced by a higher prebiotic index (1.74 ± 0.04) than galacto-oligosaccharides (1.12 ± 0.03) and inulin (1.27 ± 0.08), together with the highest prebiotic activity score (13.42 ± 0.27) under the experimental conditions evaluated. The XOS also demonstrated concentration-dependent gradual increase in DPPH scavenging capacity, ranging from 23.02% at 0.125 mg/mL to 75.83% at 4 mg/mL. Furthermore, the XOS showed a higher resistance to simulated gastric conditions (pH 1–5), with less than 6% hydrolysis after 6 h. Overall, the findings highlight SS as a promising lignocellulosic biomass for the sustainable production of XOS and support their potential as high-value bioproducts derived from agricultural residues.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s13068-026-02798-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149229456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A 2-pyrone-4,6-dicarboxylic acid biosensor for lignin valorization based on a newly identified transcriptional regulatory system","authors":"Kenta Tanatani,&nbsp;Hyo Suzuki,&nbsp;Masaya Fujita,&nbsp;Takuma Araki,&nbsp;Yuzo Suzuki,&nbsp;Tsuyoshi Michinobu,&nbsp;Yuichiro Otsuka,&nbsp;Masaya Nakamura,&nbsp;Eiji Masai,&nbsp;Naofumi Kamimura","doi":"10.1186/s13068-026-02797-9","DOIUrl":"10.1186/s13068-026-02797-9","url":null,"abstract":"<div><h3>Background</h3><p>Lignin is the most abundant renewable aromatic resource on Earth, yet its efficient conversion into value-added chemicals through biological funneling remains a key challenge. <i>Sphingobium lignivorans</i> SYK-6 exhibits broad metabolic capacity for lignin-derived aromatic compounds, ranging from monomers to dimers, making it a suitable host for biological funneling. Production systems for the polymer building block 2-pyrone-4,6-dicarboxylic acid (PDC) from lignin-derived aromatic compounds have been constructed using SYK-6. In this study, we developed a PDC-responsive biosensor to facilitate high-throughput screening of improved PDC-producing strains.</p><h3>Results</h3><p>PDC-assimilating bacteria were isolated from environmental samples, and their genomes were analyzed to obtain candidate PDC-responsive transcriptional regulatory systems. Among these, the LysR-type transcriptional regulator PdcR and its target promoter P_PDC from <i>Cupriavidus</i> sp. 8B were identified and characterized as a PDC-responsive system, in which PdcR is suggested to act as both a repressor and an activator. A reporter plasmid pCup1 carrying these components was introduced into a PDC hydrolase gene-deficient strain (Δ<i>ligI</i>) of SYK-6 to construct the PDC biosensor Δ<i>ligI</i>(pCup1). The biosensor was specific for PDC, with no response observed for its upstream metabolites. When vanillic acid or protocatechuic acid was supplied as a substrate, concentration-dependent fluorescence responses were observed over a range of 0.1–5 mM, demonstrating that PDC production from lignin-derived aromatic compounds can be monitored. Fluorescence increased synchronously with PDC accumulation, suggesting real-time monitoring of PDC production. Furthermore, the biosensor responded to PDC produced from aromatic compounds in softwood black liquor extract.</p><h3>Conclusions</h3><p>Δ<i>ligI</i>(pCup1) enables real-time, specific detection of PDC produced from lignin-derived aromatic compounds, including those in black liquor extract derived from lignocellulosic biomass, demonstrating applicability to screening for lignin valorization. Integration of this biosensor with diverse strain engineering approaches, including random mutagenesis, adaptive laboratory evolution, and metagenomics-based enzyme discovery, would provide a platform for efficient selection of SYK-6 strains with enhanced PDC production capability.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13681972/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149225627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genome-level insights into coordinated ethanol production and chaperone-driven stress tolerance in Bacillus cereus strain GRJBSBT-1 isolated from petroleum refinery sludge","authors":"Janayita Biswa Sarma,&nbsp;Anurabh Chakravarty,&nbsp;Lingaraj Sahoo,&nbsp;Preetom Regon,&nbsp;Kunal Boro,&nbsp;Hemen Deka,&nbsp;Bhaben Tanti,&nbsp;Saurov Mahanta","doi":"10.1186/s13068-026-02791-1","DOIUrl":"10.1186/s13068-026-02791-1","url":null,"abstract":"<div><p>Petroleum hydrocarbon contamination creates specialized ecological niches that present a source for mining microorganisms with exceptional metabolic flexibility and stress resilience. In this study, we performed a comprehensive genome-level analysis of <i>Bacillus cereus</i> strain GRJBSBT-1, isolated from petroleum refinery sludge, to elucidate the molecular coordination between ethanol production and stress tolerance, two important traits associated with microbial adaptation to ethanol-rich environments. Whole-genome sequencing revealed a 5.41-Mb circular genome with 35.3% GC content, comprising 5393 coding sequences and complete glycolytic and fermentative pathways. Functional annotation and KEGG pathway mapping identified genes associated with ethanol metabolism and protein quality-control systems involved in stress adaptation. Although several ethanol-related enzymes were detected, a complete canonical AdhE/PFOR ethanol fermentation pathway was not reconstructed. Quantitative gene expression analysis (qRT-PCR) under fermentative and ethanol-stress conditions showed significant upregulation of key fermentative genes (<i>adhE</i>, <i>pdhA</i>) and protein quality-control genes (<i>groEL</i>, <i>groES</i>), whereas the small heat-shock protein <i>hsp20</i> was selectively downregulated. This transcriptional expression profile suggests differential involvement of chaperone systems during ethanol stress adaptation. Moderate ethanol exposure (5%) was associated with increased expression of <i>groEL</i> and selected metabolic genes, indicating a potential relationship between protein quality-control processes and ethanol-associated adaptation. The contrasting regulation of <i>hsp20</i> and <i>groES</i> suggests differential transcriptional responses to ethanol exposure. However, these observations are based on targeted gene expression analyses and should be considered preliminary until validated through broader functional and systems-level investigations. Comparative analysis with supported possibilities of ethanologens underscores the metabolic versatility and robust stress-management capacity of strain GRJBSBT-1. These findings provide genomic and transcriptional insights into ethanol-associated metabolism and stress adaptation in <i>B. cereus</i> GRJBSBT-1 and may serve as a foundation for future investigations aimed at evaluating its biotechnological potential.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13656417/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148474878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"TrLPMO9A drives oxidative cellulose depolymerization in Trichoderma reesei and is enhanced by heterologous cellobiose dehydrogenase expression","authors":"Priscila Thihara Rodrigues,&nbsp;César Rafael Fanchini Terrasan,&nbsp;Nathalia Rodrigues Bulka,&nbsp;Evandro Antonio de Lima,&nbsp;Jose Alberto Diogo,&nbsp;Renan Yuji Miyamoto,&nbsp;Felipe Jun Fuzita,&nbsp;Joaquim Martins Junior,&nbsp;Lucia Daniela Wolf,&nbsp;Adriano Freitas Lima,&nbsp;Douglas Alvaredo Paixão,&nbsp;Meiski Maria Vedovatto,&nbsp;Lara de Oliveira Arinelli,&nbsp;William Godoy,&nbsp;Gabriela Felix Persinoti,&nbsp;Fernanda Mandelli,&nbsp;Mario Tyago Murakami","doi":"10.1186/s13068-026-02788-w","DOIUrl":"10.1186/s13068-026-02788-w","url":null,"abstract":"<div><h3>Background</h3><p>One of the most prominent mechanisms for plant cell wall deconstruction in nature, and widely employed in industry, relies on the coordinated action of hydrolytic and oxidative enzymes. However, how redox networks sustain synergistic biomass deconstruction remains incompletely understood, particularly in the industrial workhorse <i>Trichoderma reesei</i>. This fungus lacks a cellobiose dehydrogenase (CDH), a pivotal redox partner for lytic polysaccharide monooxygenases (LPMOs) in many fungal systems. Here, we investigated the oxidative machinery of <i>T. reesei</i> and the contribution of key redox-active enzymes to lignocellulose deconstruction.</p><h3>Results</h3><p>We demonstrate that the oxidative capacity of the <i>T. reesei</i> secretome is largely driven by a single enzyme, <i>Tr</i>LPMO9A, the most abundant oxidoreductase in the secretome. Proteomic analyses also revealed a lower abundance of other redox-active enzymes, including <i>Tr</i>LPMO9B and AA5 oxidase. Although deletion of <i>Tr</i>LPMO9B and <i>Tr</i>AA5 had a less pronounced impact on saccharification efficiency compared with <i>Tr</i>LPMO9A, the secretome remodeling triggered by their deletion, along with the associated decrease in saccharification performance, indicates that these redox enzymes play distinct, non-redundant roles. They likely play a system-level role within a cooperative redox network that fuels oxidative cellulose deconstruction, potentially extending beyond direct catalysis to processes associated with redox balance or protein secretion. Finally, we challenged the CDH-lacking paradigm by heterologously expressing a CDH in <i>T. reesei</i>. In vivo reconstitution of this redox duet increased biomass saccharification by 13–19%, demonstrating a strong synergistic relationship between LPMOs and CDHs even in a native CDH-lacking host.</p><h3>Conclusion</h3><p>These findings define the core oxidative machinery underlying biomass deconstruction in <i>T. reesei</i>, revealing the major cellulose-oxidative role of <i>Tr</i>LPMO9A and the importance of a cooperative redox network for efficient lignocellulose depolymerization. Moreover, successful reconstitution of CDH activity in a naturally CDH-deficient host establishes redox engineering as a promising strategy to enhance industrial biomass conversion.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s13068-026-02788-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148450972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparing deconstruction of sugarcane bagasse by a coculture of thermophilic bacteria and a fungal cellulase system","authors":"Melque Natã Silva,&nbsp;Lee R. Lynd,&nbsp;Evert K. Holwerda","doi":"10.1186/s13068-026-02787-x","DOIUrl":"10.1186/s13068-026-02787-x","url":null,"abstract":"<div><h3>Background</h3><p>Lignocellulosic biomass is a promising feedstock for sustainable bioethanol production due to its abundance, renewability, and high carbohydrate content. Among these feedstocks, sugarcane bagasse (SCB), a fibrous byproduct of sugar and ethanol mills, is particularly abundant in Brazil. However, the complex and recalcitrant structure of lignocellulose hinders its biological conversion into biofuels. There are different enzymatic architectures to overcome this challenge. Fungal enzyme systems rely on non-complexed cellulase components that act independently and are often used in combination with yeast fermentation in a simultaneous saccharification and fermentation (SSF) configuration. By contrast, thermophilic bacteria such as <i>Clostridium thermocellum</i> employ complexed cellulosome systems capable of highly efficient biomass deconstruction, which enables their application in Consolidated Bioprocessing (CBP). Although previous studies have compared these systems on various lignocellulosic feedstocks, no direct comparison exists for unpretreated sugarcane bagasse. This study aimed to compare carbohydrate solubilization between CBP with a coculture of thermophilic bacteria and SSF with a fungal enzyme–yeast system for the conversion of unpretreated SCB, and to assess the effect of particle size.</p><h3>Results</h3><p>CBP consistently achieved higher carbohydrate solubilization than SSF across all particle sizes, with improvements ranging from 1.9- to 3.7-fold. CBP was also less affected by particle size variation, showing a drop of 0.52-fold in solubilization for particles sized 0.2–4.00 mm, compared to a 2.2-fold for SSF. A strong linear correlation between C₆ and C₅ sugar solubilization was observed for both strategies. Despite differences in solubilization, residual sugar concentrations were similar between systems. Neither increased enzyme loading nor improved conditions significantly improved SSF performance, indicating intrinsic limitations in the enzymatic hydrolysis of unpretreated SCB.</p><h3>Conclusions</h3><p>This study provides the first direct comparison of unpretreated SCB deconstruction mediated by a thermophilic bacterial culture to a fungal cellulase preparation in the presence of yeast. Higher carbohydrate solubilization is seen for the bacterial system regardless of particle size. These findings highlight the potential of CBP with thermophilic bacteria as an alternative to conventional strategies. The results also reinforce the importance of standardized metrics, such as fractional carbohydrate solubilization, for cross-study comparison.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s13068-026-02787-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148450977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A characterized promoter suite enables metabolic rewiring of the acetogen Acetobacterium woodii toward ethanol production","authors":"Renaud Eynard,&nbsp;Sephora Justine,&nbsp;Rémi Hocq,&nbsp;Stefan Pflügl","doi":"10.1186/s13068-026-02790-2","DOIUrl":"10.1186/s13068-026-02790-2","url":null,"abstract":"<div><p>Acetogenic bacteria are promising platforms for converting gaseous and liquid one-carbon (C1) substrates such as carbon monoxide, carbon dioxide (CO₂), formate and methanol into fuels and chemicals, but their application is limited by sparse genetic tools and poor control over metabolic fluxes. Here, we developed a modular plasmid assembly platform and a suite of characterized native, heterologous and methanol-inducible promoters for the model acetogen <i>Acetobacterium woodii</i>, enabling rapid and tunable control of gene expression together with CRISPR-based genome editing. Using an anaerobe-compatible fluorescent reporter (pFAST), promoter strength was quantified, from medium to high expression levels. Subsequently, a minimal promoter replacement at the native <i>adhE</i> (bifunctional aldehyde-alcohol dehydrogenase) locus along with deletion of the neighboring LysR-type regulator was done employing the newly characterized promoters, demonstrating that a single promoter replacement in the genome was sufficient to shift <i>A. woodii</i> from a primarily acetogenic toward a partly ethanologenic phenotype. The engineered strain was able to produce ethanol not only from fructose but also from the C1 substrates methanol + CO₂ and formate + syngas. Together with the promoter replacement strategy, these findings underline that ethanol formation in <i>A. woodii</i> is constrained both by energy conservation and by endogenous transcriptional control. Relieving energetic bottlenecks through the choice of energetically favorable C1 substrates and decoupling <i>adhE</i> expression from its native promoter suffices to enable ethanol production from methanol + CO₂ and formate + syngas, directly linking the Wood–Ljungdahl pathway to ethanol formation. These results illustrate how small, targeted genome edits can significantly reshape carbon flux in acetogens and positions <i>A. woodii</i> as a viable chassis for C1-based bioproduction.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s13068-026-02790-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148440082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}