Biotechnology for Biofuels最新文献

{"title":"Combining transcriptomic and metabolomic insights into carbohydrate utilization by Ruminiclostridium papyrosolvens DSM2782","authors":"Mengcheng You,&nbsp;Zhenxing Ren,&nbsp;Letian Ye,&nbsp;Qiuyun Zhao,&nbsp;Ziyi Liu,&nbsp;Houhui Song,&nbsp;Chenggang Xu","doi":"10.1186/s13068-025-02619-4","DOIUrl":"10.1186/s13068-025-02619-4","url":null,"abstract":"<div><h3>Background</h3><p>Lignocellulose is the most abundant renewable bioresource on earth, and its biodegradation and utilization would contribute to the sustainable development of the global environment. <i>Ruminiclostridium papyrosolvens</i>, an anaerobic, mesophilic, and cellulolytic bacterium, produces an enzymatic complex known as the cellulosome. As one of the most highly evolved species among <i>Ruminiclostridium</i>-type species, <i>R. papyrosolvens</i> is particularly relevant for understanding how cellulolytic clostridia modulate their biomass degradation mechanisms in response to diverse carbon sources.</p><h3>Results</h3><p>Our study investigates the transcriptional responses of <i>Ruminiclostridium papyrosolvens</i> to different carbon sources to understand its lignocellulose utilization. Using RNA-seq, we analyzed gene expression under glucose, cellobiose, xylan, cellulose, and corn stover, identifying distinct metabolic preferences and regulatory responses. We found significant gene expression changes under corn stover compared to other carbon sources, with enrichment in ABC transporters and cell growth pathways. CAZyme gene expression was regulated by TCSs, affecting sugar transporter systems. Metabolic profiling showed <i>R. papyrosolvens</i> produced more complex metabolites during corn stover fermentation, revealing its adaptability to various carbon sources and implications for metabolic engineering.</p><h3>Conclusion</h3><p>This study not only uncovers the intricate response mechanisms of <i>R. papyrosolvens</i> to lignocellulose and its hydrolysates, but it also outlines the strategy for using <i>R. papyrosolvens</i> as a cellulolytic chassis in genetic engineering.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-025-02619-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471947","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":"Discovery of a novel translation-machinery-associated protein that positively correlates with cellulase production","authors":"Kexuan Ma,&nbsp;Panpan Zhang,&nbsp;Jian Zhao,&nbsp;Yuqi Qin","doi":"10.1186/s13068-025-02624-7","DOIUrl":"10.1186/s13068-025-02624-7","url":null,"abstract":"<div><h3>Background</h3><p>The production of cellulases by filamentous fungi is a crucial aspect of sustainable bioproduction from renewable lignocellulosic biomass. Following the transcription of cellulase genes in the nucleus, a complex pathway involving translation, folding, and secretion is required to produce extracellular cellulases. Most studies about cellulase production have focused on examining transcriptional regulatory mechanisms and enhancement of enzyme gene levels; comparatively, little is known about protein translation and secretion for cellulase production.</p><h3>Results</h3><p>A translation-machinery-associated (TMA) protein PoTma15 was identified in cellulosic <i>Penicillium oxalicum</i>. The PoTma15 is conserved in various filamentous fungi, but not in yeast, plants, or animals. All homologous proteins of PoTma15 have previously been uncharacterized. PoTma15 was initially thought to be one of the putative interactors of transcription factor PoXlnR, as it was preyed by tandem affinity purification (TAP) coupled with the mass spectrometry (TAP–MS) technique using PoXlnR as the bait. Subsequent research revealed that PoTma15 is associated with the translation machinery. The top three proteins associated with PoTma15 are orthologs of <i>Saccharomyces cerevisiae</i> translation-machinery-associated protein (Tma19), translation elongation factor eIF5A, and ribosomal protein S28, respectively. PoTma15 is widely distributed in fungal hyphae and positively correlates with the production of cellulases and extracellular proteins. Deleting the Po<i>tma15</i> gene (Δ<i>tma15</i>) decreased cellulase production, while overexpressing the Po<i>tma15</i> gene (OE<i>tma15</i>) increased cellulase production. However, the Δ<i>tma15</i> mutant was not observed to have downregulated transcript levels of major (hemi)cellulase and amylase genes, compared to the <i>P</i>. <i>oxalicum</i> wild type (WT). The production of extracellular cellulases and extracellular proteins of the Δ<i>tma15</i> mutant was less affected by cycloheximide, an inhibitor of eukaryotic translation elongation, compared to the WT strain and OE<i>tma15</i> mutant<i>,</i> suggesting a stronger resistance to the translation-inhibiting effects of cycloheximide in the Δ<i>tma15</i> mutant. The results demonstrate that PoTma15 is a translation-machinery-associated protein that affects translation elongation and, consequently, the production of enzyme proteins.</p><h3>Conclusions</h3><p>PoTma15 is the first TMA protein characterized in cellulosic filamentous fungi and the first TMA protein used in fungi to increase cellulase production. PoTma15’s role in the production of cellulases and total extracellular proteins suggests that not only can it be used to widen the cellulase production pathway, but can even be engineered as a target to improve the production of other heterologous protein or bioproducts using filamentous fungi as cell factories in the future.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-025-02624-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471946","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":"Structural changes and cellulose ultrastructure mapped with electron microscopy and SAXS after enzymatic hydrolysis of mildly steam pretreated Norway spruce","authors":"Maria E. F. Brollo,&nbsp;Fabio Caputo,&nbsp;Polina Naidjonoka,&nbsp;Lisbeth Olsson,&nbsp;Eva Olsson","doi":"10.1186/s13068-025-02616-7","DOIUrl":"10.1186/s13068-025-02616-7","url":null,"abstract":"<div><h3>Background</h3><p>The efficient use of softwood in biorefineries requires harsh pretreatment conditions to overcome biomass recalcitrance. While this allows the solubilization of hemicellulose, it also leads to the formation of compounds that act inhibitory against microorganisms during the fermentation step. To improve the efficacy of biomass utilization and identify optimal processing conditions, we evaluated the microstructural alterations occurring during pretreatment and enzymatic hydrolysis in Norway spruce. The biomass was steam pretreated at six different severities defined by two different temperatures (180 °C and 210 °C), with and without the addition of various acids (HAc, H₃PO₄, H₂SO₄, SO₂). After pretreatment, the materials were enzymatically hydrolysed using a cellulolytic cocktail (Celluclast + Novozym188) supplemented with a hemicellulolytic cocktail (Ultraflo). Scanning electron microscopy and small angle X-ray scattering were utilized to evaluate the structural changes, of the differently steam pretreated materials, before and after the enzymatic hydrolysis.</p><h3>Results</h3><p>Scanning electron microscopy revealed increased surface roughness and pore enlargement in all the materials after enzymatic hydrolysis. The higher the severity of the pretreatment, the more the surface was rough since it was easier for the enzymes to access the binding site. As revealed by small angle X-ray scattering (SAXS), increasing the enzymatic hydrolysis of hemicellulose did not result in further collapse of cellulose. In line with the SAXS result, a qualitative evaluation of the cellulose surface using Congo red showed a larger exposed cellulose surface area after enzymatic hydrolysis.</p><h3>Conclusions</h3><p>The present study reports the microstructural changes caused by pretreatment and enzymatic hydrolysis of Norway spruce. By enzymatically increasing the hemicellulose hydrolysis, the exposed cellulose surface area increases meaning that the cellulose might be easier to access for the enzymes. Structural analysis of biomass after enzymatic hydrolysis can direct the choice of enzymes for improved saccharification efficiency.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-025-02616-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465986","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":"Characterization of microalgal β-carotene and astaxanthin: exploring their health-promoting properties under the effect of salinity and light intensity","authors":"Aditi,&nbsp;Rupesh Bhardwaj,&nbsp;Ankush Yadav,&nbsp;Prashant Swapnil,&nbsp;Mukesh Meena","doi":"10.1186/s13068-025-02612-x","DOIUrl":"10.1186/s13068-025-02612-x","url":null,"abstract":"<div><p>Microalgae are promising sources of valuable carotenoids like β-carotene and astaxanthin with numerous health benefits. This review summarizes recent studies on producing these carotenoids in microalgae under different salinity and light-intensity conditions, which are key factors influencing their biosynthesis. The carotenoid biosynthesis pathways in microalgae, involving the methylerythritol phosphate pathway in chloroplasts, are described in detail. The effects of high salinity and light stress on stimulating astaxanthin accumulation in species like <i>Haematococcus pluvialis</i> and <i>Chromochloris zofingiensis</i> and their synergistic impact are discussed. Similarly, the review covers how high light and salinity induce β-carotene production in <i>Dunaliella salina</i> and other microalgae. The diverse health-promoting properties of astaxanthin and β-carotene, such as their antioxidant, antiinflammatory, and anticancer activities, are highlighted. Strategies to improve carotenoid yields in microalgae through environmental stresses, two-stage cultivation, genetic engineering, and metabolic engineering approaches are evaluated. Overall, this review highlights advancements in β-carotene and astaxanthin production reporting the different microalgal capability to produce carotenoids under different stress level like 31.5% increase in β-carotene accumulation in <i>Dunaliella salina</i> and astaxanthin productivity reaching 18.1 mg/L/day in <i>Haematococcus lacustris</i>. It also explores novel biotechnological strategies, including CRISPR–Cas9, for enhancing carotenoid yield.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-025-02612-x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143423152","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":"Lactic whey as a potential feedstock for exopolysaccharide production by microalgae strain Neochloris oleoabundans UTEX 1185","authors":"Daniel Moisés Paredes-Molina,&nbsp;Miguel A. Cervantes-López,&nbsp;Domancar Orona-Tamayo,&nbsp;Nancy E. Lozoya-Pérez,&nbsp;Flora I. Beltrán-Ramírez,&nbsp;Juan Vázquez-Martínez,&nbsp;Karla L. Macias-Sánchez,&nbsp;Sergio Alonso-Romero,&nbsp;Elizabeth Quintana-Rodríguez","doi":"10.1186/s13068-024-02595-1","DOIUrl":"10.1186/s13068-024-02595-1","url":null,"abstract":"<div><h3>Background</h3><p>Lactic whey, a significant agro-industrial byproduct, poses environmental risks due to its chemical composition. Despite various valorization efforts, effective utilization remains a challenge. This study explores the potential of <i>Neochloris oleoabundans</i>, a microalgae known for its metabolic versatility and resilience to adverse conditions, to produce exopolysaccharides (EPS) using lactic whey as a substrate. We compared EPS production from lactose, the primary sugar in whey, with whole lactic whey. Characterization of the EPS was performed using Fourier transform infrared spectroscopy (FT-IR) and gas chromatography–mass spectrometry (GC–MS), while morphological analysis was conducted via scanning electron microscopy (SEM). This research aims to assess the feasibility of converting lactic whey into valuable EPS, providing a sustainable approach to managing this agro-industrial waste.</p><h3>Results</h3><p>Lactic whey has produced the highest EPS and the FT-IR spectra revealed structural variations in the monomers which compose these polymers. Galactose and glucose were shown to be the primary monomers, according to GC–MS EPS analysis. SEM revealed a homogenous matrix and <i>N. oleoabundans</i>'s bioflocculant characteristics.</p><h3>Conclusions</h3><p>Microalgae <i>N. oleoabundans</i> can produce EPS using lactic whey as feedstock and it has the potential to be employed as a wastewater treatment.</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":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-024-02595-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143396713","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":"Newly isolated halotolerant Gordonia terrae S-LD serves as a microbial cell factory for the bioconversion of used soybean oil into polyhydroxybutyrate","authors":"Song Xu,&nbsp;Ruiqin Han,&nbsp;Lidan Tao,&nbsp;Zhipeng Zhang,&nbsp;Junfei Gao,&nbsp;Xinyuan Wang,&nbsp;Wei Zhao,&nbsp;Xiaoxia Zhang,&nbsp;Zhiyong Huang","doi":"10.1186/s13068-025-02613-w","DOIUrl":"10.1186/s13068-025-02613-w","url":null,"abstract":"<div><p>Polyhydroxybutyrate (PHB) is a class of biodegradable polymers generally used by prokaryotes as carbon sources and for energy storage. This study explored the feasibility of repurposing used soybean oil (USO) as a cost-effective carbon substrate for the production of PHB by the strain <i>Gordonia terrae</i> S-LD, marking the first report on PHB biosynthesis by this rare actinomycete species. This strain can grow under a broad range of temperatures (25–40 ℃), initial pH values (4–10), and salt concentrations (0–7%). The findings indicate that this strain can synthesize PHB at a level of 2.63 ± 0.6 g/L in a waste-containing medium containing 3% NaCl within a 3 L triangular flask, accounting for 66.97% of the cell dry weight. Furthermore, ¹H NMR, ¹³C NMR, and GC–MS results confirmed that the polymer was PHB. The thermal properties of PHB, including its melting (T_m) and crystallization (T_c) temperatures of 176.34 °C and 56.12 °C respectively, were determined via differential scanning calorimetry analysis. The produced PHB was characterized by a weight-average molecular weight (M_w) of 5.43 × 10⁵ g/mol, a number-average molecular weight (M_n) of 4.00 × 10⁵ g/mol, and a polydispersity index (PDI) of 1.36. In addition, the whole genome was sequenced, and the PHB biosynthetic pathway and quantitative expression of key genes were delineated in the novel isolated strain. In conclusion, this research introduces the first instance of polyhydroxyalkanoate (PHA) production by <i>Gordonia terrae</i> using used soybean oil as the exclusive carbon source, which will enrich strain resources for future PHB biosynthesis.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-025-02613-w","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143361981","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":"Insight into the role of antioxidant in microbial lignin degradation: Ascorbic acid as a fortifier of lignin-degrading enzymes","authors":"Aipeng Li,&nbsp;Weimin Wang,&nbsp;Shuqi Guo,&nbsp;Changzhi Li,&nbsp;Xinying Wang,&nbsp;Qiang Fei","doi":"10.1186/s13068-025-02614-9","DOIUrl":"10.1186/s13068-025-02614-9","url":null,"abstract":"<div><h3>Background</h3><p>Microbial-driven lignin depolymerization has emerged as a promising approach for lignin degradation. However, this process is hindered by the limited activity of lignin-degrading enzymes. Antioxidants are crucial for maintaining redox homeostasis in living cells, which can impact the efficiency of enzymes. Ascorbic acid (AA) is well-known for its antioxidant properties, while <i>Trametes versicolor</i> is a commonly used lignin-degrading fungus capable of secreting laccase (Lac) and manganese peroxidase (MnP). Thus, AA was selected as model antioxidant and added into the culture medium of <i>T. versicolor</i> to examine the effect of antioxidants on the activity of lignin-degrading enzymes in the fungus.</p><h3>Results</h3><p>The presence of AA resulted in a 4.9-fold increase in the Lac activity and a 3.9-fold increase in the MnP activity, reaching 10736 U/L and 8659 U/L, respectively. This increase in enzyme activity contributed to a higher lignin degradation rate from 17.5% to 35.2%, consistent with observed morphological changes in the lignin structure. Furthermore, the addition of AA led to a reduction in the molecular weights of lignin and an increase in the content of degradation products with lower molecular weight, indicating more thorough degradation of lignin. Proteomics analysis suggested that the enhancement in enzyme activity was more likely to attributed to the reinforcement of AA on oxidative protein folding and transportation, rather than changes in enzyme expression.</p><h3>Conclusions</h3><p>The addition of AA enhanced the performance of enzymes responsible for lignin degradation in terms of enzyme activity, degradation rate, lignin structural change, and product mapping. This study offers a feasible strategy for enhancing the activity of lignin-degrading enzymes in the fungus and provides insights into the role of antioxidant in microbial lignin degradation.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-025-02614-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143361980","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":"Resourceful and economical designing of fermentation medium for lab and commercial strains of yeast from alternative feedstock: ‘transgenic oilcane’","authors":"Shraddha Maitra,&nbsp;Bruce Dien,&nbsp;Kristen Eilts,&nbsp;Nurzhan Kuanyshev,&nbsp;Yoel R. Cortes-Pena,&nbsp;Yong-Su Jin,&nbsp;Jeremy S. Guest,&nbsp;Vijay Singh","doi":"10.1186/s13068-025-02606-9","DOIUrl":"10.1186/s13068-025-02606-9","url":null,"abstract":"<div><h3>Background</h3><p>Sugarcane plant engineered to accumulate lipids in its vegetative tissue is being developed as a new bioenergy crop. The new crop would be a source of juice, oil, and cellulosic sugars. However, limited tolerance of industrially recognized yeasts towards inhibitors generated during the processing of lignocellulosic biomass to produce fermentable sugars is a major challenge in developing scalable processes for second-generation drop-in fuel production. To this end, hydrolysates generated from engineered sugarcane—‘oilcane’ bagasse contain added phenolics and fatty acids that further restrict the growth of fermenting microorganisms and necessitate nutrient supplementation and/or detoxification of hydrolysate which makes the fermentation process expensive. Herein, we propose a resourceful and economical approach for growing lab and commercial strains of <i>S. cerevisiae</i> on unrefined cellulosic sugars aerobically and fermentatively.</p><h3>Results</h3><p>An equal ratio of hydrolysate and juice was found optimum for growth and fermentation by lab and commercial strains of <i>Saccharomyces cerevisiae</i> engineered for xylose fermentation. The industrial strain grew and fermented efficiently under low aeration conditions having an ethanol titer, yield, specific and volumetric productivities of 46.96 ± 0.19 g/l, 0.51 ± 0.00 g/g, 0.27 ± 0.02 g/g.h and 1.95 ± 0.01 g/l.h, respectively, while the lab strain grew better under higher aeration conditions having the ethanol titer, yield, specific and volumetric productivities of 24.93 ± 0.09, 0.27 ± 0.00 g/g, 0.17 ± 0.00 g/g.h and 1.04 ± 0.00 g/l.h, respectively. Acclimation of cultures in a blended medium significantly improved the performance of the yeast strains.</p><h3>Conclusions</h3><p>The addition of transgenic oilcane juice, which is inedible and rich in amino acids, to the hydrolysate averted the need for expensive nutrient supplementation and detoxification steps of hydrolysate. The approach provides an economical solution to reduce the cost of fermentation at an industrial scale for second-generation drop-in fuel production.</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":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11786580/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143076707","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":"Synergetic effect of fungal pretreatment and lignin modification on delignification and saccharification: a case study of a natural lignin mutant in mulberry","authors":"James Paul T. Madigal,&nbsp;Masami Terasaki,&nbsp;Masatsugu Takada,&nbsp;Shinya Kajita","doi":"10.1186/s13068-025-02611-y","DOIUrl":"10.1186/s13068-025-02611-y","url":null,"abstract":"<div><h3>Background</h3><p>Fungal pretreatment for partial separation of lignocellulosic components may reduce lignocellulose recalcitrance during the production of biofuels and biochemicals. Quantitative and qualitative modification of plant lignin through genetic engineering or traditional breeding may also reduce the recalcitrance. This study was conducted to examine the effects of combining these two approaches using three white rot fungi and mulberry wood with an altered lignin structure.</p><h3>Results</h3><p>Mulberry wood prepared from homozygotes or heterozygotes with a loss-of-function in the cinnamyl alcohol dehydrogenase gene (<i>CAD</i>) was pretreated with three fungal species. Both heterozygous (<i>CAD</i>/<i>cad</i>) and homozygous (<i>cad</i>/<i>cad</i>, null mutant) mulberry plants were derived from the same parents via backcrossing between Sekizaisou (<i>cad</i>/<i>cad</i>, seed parent), a natural lignin mutant, and its F1 progeny (<i>CAD</i>/<i>cad</i>, pollen parent). Homozygote wood and the isolated lignin exhibited an abnormal color. Lignin in homozygotes without fungal pretreatment exhibited a lower syringyl/guaiacyl ratio, molar mass, and thioacidolysis product yield than those in heterozygotes. Pretreatment with <i>Phanerochaete chrysosporium</i> achieved the highest delignification efficiency with a significant reduction in the cellulose content in both mulberry genotypes. In contrast, <i>Ceriporiopsis subvermispora</i> selectively removed lignin, with a weaker reduction in the cellulose content. The degree of delignification by <i>C. subvermispora</i> was significantly higher in homozygotes than in heterozygotes. <i>Trametes versicolor</i> tended to have a lower delignification capacity and smaller effect of subsequent enzymatic sugar release toward the wood from both genotypes than the other two fungi, making it less suitable for fungal pretreatment. Thioacidolysis assays indicated that cinnamaldehyde β-O-4, a typical subunit in the homozygote lignin, did not contribute to the high degradability of the lignin. The saccharification efficiency tended to be higher in homozygote wood than in heterozygote wood under all fungal pretreatment conditions.</p><h3>Conclusions</h3><p>Although further optimization of various system conditions is required, our findings suggest that CAD deficiency promotes delignification and subsequent enzymatic saccharification and may improve the biorefining efficiency of wood when combined with fungal pretreatment.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11776243/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143070142","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":"Biphasic lipid extraction from microalgae after PEF-treatment reduces the energy demand of the downstream process","authors":"Ioannis Papachristou,&nbsp;Natalja Nazarova,&nbsp;Rüdiger Wüstner,&nbsp;Robin Lina,&nbsp;Wolfgang Frey,&nbsp;Aude Silve","doi":"10.1186/s13068-025-02608-7","DOIUrl":"10.1186/s13068-025-02608-7","url":null,"abstract":"<div><h3>Background</h3><p>The gradual extrusion of water-soluble intracellular components (such as proteins) from microalgae after pulsed electric field (PEF) treatment is a well-documented phenomenon. This could be utilized in biorefinery applications with lipid extraction taking place after such an ‘incubation’ period, i.e., a post-PEF-treatment step during which the biomass is left undisturbed before any further processing. The goal of this work was to further explore how this incubation could improve lipid extraction.</p><h3>Results</h3><p>Experiments were conducted on wet, freshly harvested <i>Auxenochlorella protothecoides</i>, treated with 0.25 or 1.5 MJ/kg_DW and incubated for 24 h. Lipid extraction took place with a monophasic ethanol:hexane:water, 1:0.41:0.04 vol/vol/vol mixture with a 75.6 mL solvent per 1 g of dry biomass ratio. The kinetics of the extraction were studied with samples taken between 10 and 1080 min from fresh and incubated biomass. The yields at 10 min were significantly increased with incubation compared to without (31.2% dry weight compared to 1.81%, respectively). The experimental data were fitted with the Patricelli model where extraction occurs in two steps, a rapid washing of immediate available lipids and a slower diffusion one. During Nile-Red staining of microalgae and microscopy imaging, a shift of emission from both GFP and RFP channels to mostly RFP was observed indicating an increase in the polarity of the environment of Nile-Red. These led to an adaption of a biphasic ethanol:hexane:water 1:6:0.4 vol/vol/vol solvent with 37 mL solvent per 1 g of dry biomass ratio which while ineffective on fresh biomass, achieved a 27% dry weight yield from incubated microalgae. The extraction efficiency in the biphasic route was lower compared to the monophasic (i.e., 69% and 95%, respectively). It was compensated however, by the significant solvent reduction (37 mL to 75.6 mL respectively), in particular the ethanol minimization. For the extraction of 1 L lipids, it was estimated that the energy consumption ratio for the biphasic process was 1.6 compared to 9.9 for monophasic, making clearly the most preferential one.</p><h3>Conclusions</h3><p>This biphasic approach significantly reduces solvent consumption and the respective energy requirement for solvent recovery. Incubation thus could majorly improve the commercialization prospects of the process.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11776281/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143061638","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}