Biotechnology for Biofuels最新文献

{"title":"Off-gas capture: a promising strategy for removal and recovery of toxic bioproducts in aerobic fermentation","authors":"Carolina Araujo Barcelos,&nbsp;Daniel Mendez-Perez,&nbsp;Taek Soon Lee,&nbsp;Eric Sundstrom","doi":"10.1186/s13068-026-02764-4","DOIUrl":"10.1186/s13068-026-02764-4","url":null,"abstract":"<div><p>In many bioprocesses, maximum achievable titers are limited below economically viable levels by toxic accumulation of the primary end-product. To combat end-product inhibition, a variety of in situ product removal technologies have been developed to selectively remove or partition toxic bioproducts, thereby prolonging fermentation and improving overall process efficiency. Use of an in situ organic overlay to partition toxic hydrophobic products is a commonly employed approach, but this technique occupies valuable space in the fermentor, imposes replacement costs for unrecovered solvent, and increases downstream separation due to formation of stable emulsions. In addition, for many volatile hydrophobic products produced under aerobic conditions—including medium-chain alcohols, esters, monoterpenes, and other aviation fuel precursors—a significant fraction of the product is volatilized to the fermentor off-gas and must be recovered separately to maximize product yield. To address these challenges, we explore the viability of leveraging existing aeration energy to fully strip and recover volatile products from the fermentor off-gas. We compare two strategies of in situ product removal—liquid–liquid extraction and direct recovery from fermentation off-gas—for the production and recovery of intermediates used to generate isoprene and DMCO (1,4-dimethylcyclooctane), a high-performance jet fuel. We evaluate product toxicity, solvent toxicity, solvent partitioning, and the impact of aeration and internal overlay configurations on product volatilization rates. We then optimize product recovery from fermentor off-gas via condensation in chilled solvent, achieving 84% capture efficiency. In addition to greatly simplifying downstream processing, relying on aeration for product volatilization in the absence of an internal overlay enables continuous removal of toxic fermentation products up to maximum isoprenol titers of 20.4 g/L, the highest reported to date.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s13068-026-02764-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147792088","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":"Advances, challenges, and future directions towards a cellulolytic Escherichia coli","authors":"Eliseo R. Molina-Vázquez,&nbsp;Ricardo Oropeza,&nbsp;Alfredo Martinez","doi":"10.1186/s13068-026-02769-z","DOIUrl":"10.1186/s13068-026-02769-z","url":null,"abstract":"<div><h3>Background</h3><p><i>Escherichia coli</i> has been widely engineered as a microbial chassis for the biosynthesis of a broad spectrum of products ranging from basic building blocks and biocommodities to high-value fine chemicals and drugs. However, most current bioprocesses still rely on conventional feedstocks such as corn-derived glucose and sugarcane-derived sucrose, which are also demanded by established food and industrial supply chains. Consequently, allocating these sugars to the production of biocommodities, which are required in large quantities and at low cost, may exacerbate concerns about food security and undermine the long-term sustainability of large-scale biomanufacturing relative to low-cost petrochemical routes, particularly for bulk chemicals.</p><h3>Main text</h3><p>Lignocellulosic biomass, derived from agricultural residues and urban waste, presents a low-cost, renewable, and abundant alternative source of fermentable sugars. Composed of an intricate matrix of cellulose, hemicellulose, and lignin, lignocellulose exhibits a high degree of structural recalcitrance. To access its fermentable components, biomass typically needs physicochemical pretreatment and enzymatic saccharification using commercial cellulases. Unfortunately, these enzymes are expensive, and their optimal catalytic properties are typically achieved under conditions incompatible with those required by conventional <i>E. coli</i> production strains, thereby complicating the integration of saccharification and fermentation processes. To overcome this barrier, significant efforts have been made to engineer recombinant cellulolytic <i>E. coli</i> strains capable of degrading cellulose. Strategies explored include intracellular expression of cellulases followed by induced lysis, enzyme secretion via signal peptides, and surface display of cellulolytic enzymes, among others.</p><h3>Conclusions</h3><p>Key advances toward achieving saccharolytic <i>E. coli</i> have been achieved. Proof-of-concept studies have demonstrated simultaneous saccharification and fermentation using pretreated lignocellulosic biomass, and high-throughput platforms for evolving cellulolytic enzymes have been established. Despite substantial progress, knowledge in this field remains fragmented across diverse studies. This review consolidates key advancements in the development of cellulolytic <i>E. coli</i> strains, emphasizing the molecular, metabolic, and physiological engineering strategies employed. It also highlights key challenges and future directions for integrating lignocellulose utilization into industrial <i>E. coli</i>-based bioprocesses.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s13068-026-02769-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147792055","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":"Biotechnological applications of D-xylose-fermenting autochthonous yeasts in lignocellulosic biorefineries","authors":"Demitreo Duarte Machado,&nbsp;Carolina Backhaus Martinez,&nbsp;Vinícius Pellini Souza,&nbsp;Mariana Machado Linck,&nbsp;Diego Bonatto","doi":"10.1186/s13068-026-02765-3","DOIUrl":"10.1186/s13068-026-02765-3","url":null,"abstract":"<div><p>The efficient fermentation of D-xylose by yeasts remains a major bottleneck for the sustainable production of second-generation bioethanol, as this pentose represents a substantial fraction of hemicellulosic sugars in lignocellulosic biomass. While conventional industrial yeasts show limited native capacity for D-xylose utilization, numerous autochthonous (native or wild-derived) yeasts isolated from natural environments harbor metabolic traits that have been naturally selected and enable effective pentose assimilation under challenging conditions. Understanding and harnessing this diversity is essential for advancing lignocellulosic biorefineries. This review synthesizes current knowledge on D-xylose-fermenting yeasts from natural ecosystems, with emphasis on their ecological diversity, taxonomic classification, physiological traits, and biotechnological relevance. Yeasts in genera such as <i>Scheffersomyces,</i> <i>Spathaspora,</i> <i>Candida,</i> and <i>Meyerozyma</i> exhibit efficient D-xylose metabolism via distinct enzymatic strategies, although redox balance, cofactor regeneration, and sugar transport remain key constraints. Many of these yeasts exhibit intrinsic tolerance to inhibitors derived from biomass pretreatment and adaptability to variations in oxygen availability, temperature, and osmotic stress, which are critical attributes for industrial applications. In addition, several species produce hydrolytic enzymes that partially degrade lignocellulosic substrates during fermentation, thereby supporting process integration and consolidation. Beyond ethanol production, D-xylose metabolism in yeasts can be redirected toward value-added bioproducts such as xylitol and organic acids, broadening the economic potential of lignocellulosic feedstocks. Advances in molecular taxonomy, adaptive evolution, metabolic engineering, and omics-based analyses have substantially improved fermentation performance and robustness, enabling more rational strain selection and targeted improvement. By combining phylogenetic-guided strain identification, adaptive and genetic improvement, systems-level characterization, and industrial process integration, this review provides a comprehensive framework for translating natural yeast diversity into efficient platforms for second-generation bioethanol and diversified bioprocesses. Such an integrated perspective is essential for overcoming current technical limitations and for advancing sustainable, biomass-based biorefineries.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s13068-026-02765-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147792108","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":"Prospective life-cycle assessment of CORSIA sustainable aviation fuels under evolving electricity and hydrogen carbon intensities","authors":"Uisung Lee,&nbsp;Matteo Prussi,&nbsp;Alessandro Martulli,&nbsp;Michael Wang,&nbsp;Robert Malina","doi":"10.1186/s13068-026-02763-5","DOIUrl":"10.1186/s13068-026-02763-5","url":null,"abstract":"<div><p>Most life-cycle assessments (LCAs) of alternative fuels evaluate electricity and hydrogen inputs using static or scenario-based carbon intensity assumptions. This study quantifies the impact of electricity and hydrogen on the life-cycle greenhouse gas (GHG) emissions of sustainable aviation fuels (SAFs). By coupling emission intensity projections for electricity grids and hydrogen production with Argonne National Laboratory’s R&amp;D GREET model, and following the life-cycle assessment (LCA) method of the International Civil Aviation Organization, we estimate life-cycle GHG emissions effects for two SAF pathways with comparatively high technology readiness levels: hydroprocessed esters and fatty acids (HEFA) from waste fats (tallow) and alcohol-to-jet (ATJ) from corn grain ethanol. Under the assumed trajectories for electricity grid decarbonization and hydrogen production carbon intensities, life-cycle GHG emissions of tallow HEFA and corn grain ATJ are estimated to be 7.7–12.5 <span>(textrm{gCO}_2)</span>e/MJ_fuel lower in 2035 and 9.6–13.7 <span>(textrm{gCO}_2)</span>e/MJ_fuel lower in 2050 relative to 2022 values. Additional facility-level mitigation measures, including carbon capture and waste heat utilization, could further reduce emissions per unit SAF. The work provides a prospective assessment by replacing static pathway intensities with a prospective LCA that couples SAF pathways to time-evolving electricity/hydrogen CIs and facility-level mitigation, quantifying dynamic GHG reductions to 2050. These findings underscore the importance of incorporating prospective energy system changes into SAF LCAs to more accurately capture future mitigation potential and inform effective aviation climate strategies.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s13068-026-02763-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147619318","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":"Flavin-dependent monooxygenases as versatile biocatalysts in biomanufacturing: mechanisms, engineering, and applications","authors":"Yong Li,&nbsp;Ling Zhao,&nbsp;Xin Pu,&nbsp;Biao Geng,&nbsp;Wei Liu,&nbsp;Jie Gao,&nbsp;Xiaowei Peng,&nbsp;Yejun Han","doi":"10.1186/s13068-026-02755-5","DOIUrl":"10.1186/s13068-026-02755-5","url":null,"abstract":"<div><p>Flavin-dependent monooxygenases (FMOs) are versatile oxidative biocatalysts that catalyze a wide array of oxygenation reactions, such as hydroxylation, epoxidation, Baeyer–Villiger oxidation, and halogenation. These enzymes utilize flavin adenine dinucleotide (FAD) or flavin mononucleotide (FMN) as cofactors to mediate selective incorporation of oxygen into diverse substrates. Owing to their remarkable chemo-, regio-, and stereoselectivity, FMOs have attracted increasing attention as powerful tools for biomanufacturing. Recent advances in enzyme engineering, structural biology, and computational design have expanded the catalytic diversity of FMOs and enabled their integration into biocatalysis frameworks. Moreover, developments in cofactor regeneration, directed evolution, and cell-free biotransformation have improved FMOs’ catalytic efficiency and scalability. Despite these advances, challenges such as limited thermostability, oxygen transfer efficiency, and substrate scope remain obstacles for industrial applications of FMOs. This review summarizes the structural characteristics, catalytic mechanisms, and engineering strategies of FMOs, highlights recent progress in their integration into biocatalysis platforms, and discusses current limitations and possible solutions. Insights into improving FMO catalytic performance and expanding their potential as next-generation biocatalysts for biosynthesis will be provided.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s13068-026-02755-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147617198","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":"Metabolic engineering of Bacillus subtilis for high-yield surfactin production","authors":"Yong Wang,&nbsp;Hanqing Li,&nbsp;Yue Mao,&nbsp;Pengfei Li,&nbsp;Haizhen Wu,&nbsp;Jiang Ye,&nbsp;Huizhan Zhang","doi":"10.1186/s13068-026-02762-6","DOIUrl":"10.1186/s13068-026-02762-6","url":null,"abstract":"<div><p>The industrial application of surfactin has been constrained by the low production capacity of <i>Bacillus subtilis</i>. This study developed a high-yield, high-tolerance surfactin-producing strain through a multi-level metabolic engineering strategy. First, we constructed an enhanced P43 promoter (P43LN) by extending its upstream region from 260 to 520 bp and pairing it with a cognate 5′ UTR, which exhibited more than threefold higher activity than the commonly used core P43 promoter, providing a versatile tool for stable and high-level expression of key genes. Based on this, the native <i>srfA</i> promoter in the oilfield-derived <i>B. subtilis</i> TD7 was replaced with the P43 promoter, yielding the engineered strain TP1. Subsequently, systematic knockout of competing antimicrobial peptide synthesis gene clusters (<i>pps</i>, <i>bac</i>, and <i>pks</i>) increased surfactin titer to 2.78 g/L. Further synergistic enhancement of NADPH regeneration (via <i>zwf</i> overexpression) and cellular tolerance (via efflux pump gene <i>yerP</i> overexpression) resulted in the final strain TS8, which achieved a shake-flask surfactin titer of 3.51 g/L, representing a 102.7% increase in per-OD₆₀₀ productivity. This work successfully integrates promoter engineering, metabolic flux redistribution, and tolerance modules, not only significantly improving surfactin production but also providing a powerful expression and systematic optimization toolkit for <i>B. subtilis</i>, laying a technical foundation for the efficient biomanufacturing of complex natural products.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture><span>The alternative text for this image may have been generated using AI.</span></div></div></figure></div></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s13068-026-02762-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147617252","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":"Frequency-dependent modulation of functional single cell oils in Rhodotorula sp. and Aspergillus flavus under alternating current stimulation","authors":"Hadeel El-Shall,&nbsp;Afaf A. Gliwan,&nbsp;Mamdouh M. Shawki,&nbsp;Marwa M. Eltarahony,&nbsp;Moataz M. Fahmy","doi":"10.1186/s13068-026-02757-3","DOIUrl":"10.1186/s13068-026-02757-3","url":null,"abstract":"<div><p>Microbial lipid metabolism can be modulated by non-invasive physical stimuli, offering a sustainable route to tailor functional biomaterials. Here, we report for the first time the frequency-dependent modulation of single cell oils (SCOs) in the oleaginous yeast <i>Rhodotorula</i> sp. and the filamentous fungus <i>Aspergillus flavus</i> through alternating current (AC) electrostimulation during exponential and stationary growth phases. Cultures were exposed to AC frequencies ranging from 100 Hz to 1 MHz under nitrogen-limited conditions, and lipid yield, fatty acids (FAs) composition, and ultrastructural changes were assessed via gravimetric analysis, GC–MS, FTIR spectroscopy, and TEM imaging. Low-frequency stimulation (100 Hz–1 kHz) significantly enhanced lipid accumulation (up to 2.7-fold above controls) with enrichment in oleic acid, a monounsaturated fatty acid (MUFA). Mid-frequency exposure (10–100 kHz) favored MUFAs accumulation at early stages but later suppressed unsaturation, implying transient desaturase modulation. High-frequency treatment (1 MHz) selectively enriched polyunsaturated fatty acids (PUFAs), particularly linoleic acid (ω-6), during prolonged cultivation, linking oxidative stress responses to lipid remodeling. TEM revealed frequency-specific ultrastructural adaptations, including lipid droplet enlargement, membrane invaginations, and autophagic activity. Together, these results demonstrate that AC frequency acts as a tunable “metabolic switch” capable of enhancing both the quantity and quality of microbial lipids. This strategy offers strong potential for scalable production of biofunctional lipids relevant to biofuels, nutraceuticals, biomedical, and advanced biomaterial applications, which aligns with various United Nations Sustainable Development Goals (SDGs) including zero hunger (SDG 2), good health and well-being (SDG 3), and affordable and clean energy (SDG 7).</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s13068-026-02757-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147610857","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":"Evidencing the capability of Debaryomyces hansenii for using VFAs from organic digestates as feedstock","authors":"Mònica Estrada,&nbsp;Elia Tomás-Pejó,&nbsp;José L. Martínez","doi":"10.1186/s13068-026-02761-7","DOIUrl":"10.1186/s13068-026-02761-7","url":null,"abstract":"<div><h3>Background</h3><p>Volatile fatty acids (VFAs) have emerged as promising alternative substrates to replace sugars (such as glucose) for microbial production, which can help reduce production costs. Moreover, VFAs can be sustainably produced through anaerobic fermentation (AF) of organic waste streams, revalorizing these by-products and thus contributing to the transition toward a circular bio-based economy. However, finding microorganisms able to tolerate and consume VFAs is a crucial need to achieve this goal. This study assesses, for the first time, the ability of the halotolerant and oleaginous non-conventional yeast <i>Debaryomyces hansenii</i> (<i>D. hansenii</i>) to metabolize VFAs as the sole carbon and energy source, using different total VFAs concentrations and acid profiles in synthetic media as well as microalgae VFAs-rich digestates.</p><h3>Results</h3><p><i>D. hansenii</i> was able to grow with up to 15 g/L of total VFAs and metabolize all of them when acetic acid was the main acid present in the medium. An improved growth of the yeast was observed when using an organic VFAs-rich digestate as a feedstock derived from the AF of microalgae biomass, compared to growth in synthetic media. In this case, a biomass yield of 0.43 g/g was achieved. Finally, the capability of <i>D. hansenii</i> to produce and accumulate lipids from VFAs was assessed, showing that when the C:N ratio of the medium was increased to 200, the yeast accumulated up to 20.87% w/w of lipids, being oleic, palmitic, and linoleic acids the primary fatty acids produced. Interestingly, the odd-chain fatty acid C17 was also detected.</p><h3>Conclusions</h3><p>Our study shows the potential of <i>D. hansenii</i> for bioconversion of VFAs, particularly from organic digestates, into industrially high-value compounds such as lipids. This particular yeast exhibits a preference for acetic acid and the ability to metabolize a wide range of VFAs when this acid is supplied in higher concentrations than the others. Our research moreover highlights the importance of C:N ratio and VFA composition for lipid accumulation in <i>Debaryomyces and</i> furthermore provides a foundation for further exploration of <i>D. hansenii</i> as a suitable candidate for sustainable bioproduction of microbial oils.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s13068-026-02761-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147596843","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":"Fungal–bacterial interaction networks in lignocellulose degradation: an integrated ecological and mechanistic perspective","authors":"Yun-Yeong Lee,&nbsp;Jeonghee Yun","doi":"10.1186/s13068-026-02760-8","DOIUrl":"10.1186/s13068-026-02760-8","url":null,"abstract":"<div><p>Lignocellulosic biomass (LCB) degradation is the process by which fungi and bacteria contribute complementarily at multiple organizational levels. This review integrates their enzymatic, ecological, and metabolic roles, and suggests the linkage structure between the microbial community dynamics and the design of synthetic microbial consortia. Fungi and bacteria form functionally coordinated interactions involving structural modification of substrates, microenvironmental regulation, and the continuity of metabolic pathways. These interactions enable degradation efficiencies that are not achievable under monoculture conditions. Recent omics-based studies conducted in LCB-rich environments show that this cooperative relationship is commonly observed in natural ecosystems. Furthermore, analyses of enzyme gene distributions and functional roles further indicate that key microbial members can be selected to construct simplified consortia without reproducing the full complexity of natural communities. Therefore, this review highlights a shift from viewing LCB degradation as a set of isolated enzymatic steps or single-strain activities to understanding it as a network-level biological process shaped by fungal–bacterial interactions. This perspective can provide a theoretical foundation for the rational design and optimization of microbial consortia in future bioconversion applications.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13159211/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147596860","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":"In situ product removal via reactive extraction in itaconic acid fermentation with Ustilago cynodontis","authors":"Katharina Maria Saur,&nbsp;Luca Antonia Grebe,&nbsp;Lina Wilke,&nbsp;Fabian Roweda,&nbsp;Pia Ergezinger,&nbsp;Robert Kiefel,&nbsp;Jørgen Barsett Magnus,&nbsp;Andreas Jupke","doi":"10.1186/s13068-026-02753-7","DOIUrl":"10.1186/s13068-026-02753-7","url":null,"abstract":"<div><p>Bio-based carboxylic acids are key platform chemicals for a circular economy, offering sustainable alternatives to fossil-derived products. Yet, high substrate and processing costs, along with narrow profit margins, restrict industrial-scale bioproduction. <i>In situ</i> product removal (ISPR) holds the potential to increase productivity and yield in fermentations by circumventing product inhibition. Thus, it presents a promising process intensification measure to bridge the commercial gap between bio-based and petrochemical platform chemicals. One effective method for product recovery is reactive extraction with trioctylamine. In the present study, this method was applied to itaconic acid (ITA) fermentations with <i>Ustilago cynodontis</i>. First, the successful operation of dispersion-based apparatuses for reactive extraction was proven using small-scale mixer–settlers, with 1-octanol and the biocompatible 2-octanone as diluents. We then developed an improved feeding profile, lowering byproduct formation by 72 %. Subsequently, we demonstrated the feasibility of ISPR using a perfusion bioreactor with an external membrane coupled to reactive extraction and back-extraction. After 233 h of fermentation, the total amount of ITA produced was increased by 26 %, and productivity was 21 % higher compared to extended-batch fermentations. However, the yield was only slightly improved by 5 %. Ultimately, we identified product toxicity far below the maximum titer of 80 g <span>(hbox {L}^{-1})</span> as a key bottleneck in ISPR fermentations with <i>U. cynodontis</i>. The results underscore the potential of ISPR and warrant further investigation in this field.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"19 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2026-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1186/s13068-026-02753-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147535044","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}