Biotechnology for Biofuels最新文献

{"title":"Engineering of the fast-growing cyanobacterium Synechococcus sp. PCC 11901 to synthesize astaxanthin","authors":"Nico Betterle,&nbsp;Eliana Gasparotto,&nbsp;Elia Battagini,&nbsp;Edoardo Ceschi,&nbsp;Francesco Bellamoli,&nbsp;Peter J. Nixon,&nbsp;Matteo Ballottari","doi":"10.1186/s13068-025-02626-5","DOIUrl":"10.1186/s13068-025-02626-5","url":null,"abstract":"<div><h3>Background</h3><p>Astaxanthin is a red pigment required by feed, nutraceutical, and cosmetic industries for its pigmentation and antioxidant properties. This carotenoid is one of the main high-value products that can nowadays be derived from microalgae cultivation, raising important industrial interest. However, state-of-the-art astaxanthin production is the cultivation of the green alga <i>Haematococcus pluvialis</i> (or <i>lacustris</i>), which faces high costs and low production yield. Hence, alternative and efficient sources for astaxanthin need to be developed, and novel biotechnological solutions must be found. The recently discovered cyanobacterium, <i>Synechococcus</i> sp. PCC 11901 is a promising photosynthetic platform for the large-scale production of high-value products, but its potential has yet to be thoroughly tested.</p><h3>Results</h3><p>In this study, the cyanobacterium <i>Synechococcus</i> sp. PCC 11901 was engineered for the first time to our knowledge to produce astaxanthin, a high-value ketocarotenoid, by expressing recombinant β-ketolase (bKT) and a β-hydroxylase enzymes (CtrZ). During photoautotrophic growth, the bKT-CtrZ transformed strain (called BC) accumulated astaxanthin to above 80% of the total carotenoid. Moreover, BC cells grew faster than wild-type (WT) cells in high light and continuous bubbling with CO₂-enriched air. The engineered strain reached stationary phase after only 4 days of growth in an airlift 80-mL photobioreactor, producing 7 g/L of dry biomass, and accumulated ~ 10 mg/L/day of astaxanthin, which is more than other CO₂-consuming multi-engineered systems. In addition, BC cells were cultivated in a 330-L photobioreactor to link lab-scale experiments to the industrial scale-up.</p><h3>Conclusions</h3><p>The astaxanthin volumetric productivity achieved, 10 mg/L/day, exceeds that previously reported for <i>Haematococcus pluvialis,</i> the standard microalgal species nowadays used at the industrial level for astaxanthin production, or for other microalgal strains engineered to produce ketocarotenoids. Overall, this work identifies a new route to produce astaxanthin on an industrial scale.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-025-02626-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143521575","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":"Design and characterization of allantoin-inducible expression systems in budding yeast","authors":"Junyi Wang,&nbsp;Jiaxue Ma,&nbsp;Xueyi Luo,&nbsp;Shuo Wang,&nbsp;Xinning Cai,&nbsp;Jifeng Yuan","doi":"10.1186/s13068-025-02630-9","DOIUrl":"10.1186/s13068-025-02630-9","url":null,"abstract":"<div><h3>Background</h3><p><i>Saccharomyces cerevisiae</i> has been extensively employed as a host for the production of various biochemicals and recombinant proteins. The expression systems employed in <i>S. cerevisiae</i> typically rely on constitutive or galactose-regulated promoters, and the limited repertoire of gene expression regulations imposes constraints on the productivity of microbial cell factories based on budding yeast.</p><h3>Results</h3><p>In this study, we designed and characterized a series of allantoin-inducible expression systems based on the endogenous allantoin catabolic system (DAL-related genes) in <i>S. cerevisiae</i>. We first characterized the expression profile of a set of DAL promoters induced by allantoin, and further combined with the galactose-inducible (GAL) system to create a highly responsive genetic switch that efficiently amplifies the output signals. The resulting allantoin–GAL system could give a ON/OFF ratio of 68.6, with 6.8-fold higher signal output over that of direct P_DAL2-controlled gene expression. Additionally, when a centromeric plasmid was used for EGFP expression, the ON/OFF ratio was increased to &gt; 67.2, surpassing the EGFP expression levels driven by the DAL2 promoter. Subsequently, we successfully demonstrated that allantoin–GAL system can be used to effectively regulate carotenoid production and cell flocculation in <i>S. cerevisiae</i>.</p><h3>Conclusions</h3><p>In summary, we characterized several allantoin-inducible DAL promoters from budding yeast and further developed a layered allantoin–GAL system that utilizes the DAL2 promoter to regulate the galactose regulon in budding yeast. The resulting allantoin–GAL system could give an impressive ON/OFF ratio that surpassed the traditional P_DAL2-controlled gene expression. It is anticipated that utilizing our allantoin-inducible system in budding yeast with allantoin as the alternative nitrogen source might favor the low-cost production of biochemicals and pharmaceuticals.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-025-02630-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143521577","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":"SANS investigation of fungal loosenins reveals substrate-dependent impacts of protein action on the inter-microfibril arrangement of cellulosic substrates","authors":"Deepika Dahiya,&nbsp;Zsuzsanna Péter-Szabó,&nbsp;Manjula Senanayake,&nbsp;Sai Venkatesh Pingali,&nbsp;Wellington C. Leite,&nbsp;James Byrnes,&nbsp;Garry W. Buchko,&nbsp;Pramod Sivan,&nbsp;Francisco Vilaplana,&nbsp;Emma R. Master,&nbsp;Hugh O’Neill","doi":"10.1186/s13068-025-02618-5","DOIUrl":"10.1186/s13068-025-02618-5","url":null,"abstract":"<div><h3>Background</h3><p>Microbial expansin-related proteins include fungal loosenins, which have been previously shown to disrupt cellulose networks and enhance the enzymatic conversion of cellulosic substrates. Despite showing beneficial impacts to cellulose processing, detailed characterization of cellulosic materials after loosenin treatment is lacking. In this study, small-angle neutron scattering (SANS) was used to investigate the effects of three recombinantly produced loosenins that originate from <i>Phanerochaete carnosa</i>, <i>Pca</i>LOOL7, <i>Pca</i>LOOL9, and <i>Pca</i>LOOL12, on the organization of holocellulose preparations from Eucalyptus and Spruce wood samples.</p><h3>Results</h3><p>Whereas the SANS analysis of Spruce holocellulose revealed an increase in inter-microfibril spacing of neighboring cellulose microfibrils following treatment with <i>Pca</i>LOOL12 and to a lesser extent <i>Pca</i>LOOL7, the analysis of Eucalyptus holocellulose revealed a reduction in the ordered arrangement of microfibrils following treatment with <i>Pca</i>LOOL12 and to a lesser extent <i>Pca</i>LOOL9. Parallel SEC-SAXS characterization of <i>Pca</i>LOOL7, <i>Pca</i>LOOL9, and <i>Pca</i>LOOL12 indicated the proteins likely function as monomers; moreover, all appear to retain a flexible disordered N-terminus and folded C-terminal region. The comparatively high impact of <i>Pca</i>LOOL12 motivated its NMR structural characterization, revealing a double-<i>psi</i> β-barrel (DPBB) domain surrounded by three α-helices—the largest nestled against the DPBB core and the other two part of loops extending from the core.</p><h3>Conclusions</h3><p>The SANS analysis of <i>Pca</i>LOOL action on holocellulose samples confirms their ability to disrupt cellulose fiber networks and suggests a progression from reducing regular order in the microfibril arrangement to increasing inter-microfibril spacing. The most impactful <i>Pca</i>LOOL, <i>Pca</i>LOOL12, was previously observed to be the most highly expressed loosenin in <i>P. carnosa</i>. Its structural characterization herein reveals its stabilization through two disulfide linkages, and an extended N-terminal region distal to a negatively charged and surface accessible polysaccharide binding groove.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-025-02618-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143521576","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 Cortinarius O-methyltransferases for the heterologous production of dermolutein and physcion","authors":"Pradhuman Jetha,&nbsp;Dominik Mojzita,&nbsp;Natalia Maiorova,&nbsp;Jorg C. de Ruijter,&nbsp;Hannu Maaheimo,&nbsp;Satu Hilditch,&nbsp;Gopal Peddinti,&nbsp;Sandra Castillo,&nbsp;Mervi Toivari,&nbsp;Merja Penttilä,&nbsp;István Molnár","doi":"10.1186/s13068-025-02625-6","DOIUrl":"10.1186/s13068-025-02625-6","url":null,"abstract":"<div><h3>Background</h3><p>Anthraquinones in the emodin family are produced by bacteria, fungi, and plants. They display various biological activities exploited, e.g., for crop protection, and may also be utilized as sustainable, bio-based colorants for the textile, paints, electronics, and cosmetic industries. Anthraquinone pigments from <i>Cortinarius</i> mushrooms have been used for artisan dyeing because they are stable, colorfast, and compatible with various dyeing methods. However, their chemical synthesis is complex and uneconomical, and harvesting wild mushrooms from forests in commercial quantities is not feasible.</p><h3>Results</h3><p>Here, we use genomics, transcriptomics, and synthetic biology to uncover the biosynthesis of the anthraquinone scaffold compounds emodin and endocrocin, and their methylation to the yellow pigments physcion and dermolutein in <i>Cortinarius semisanguineus</i> and <i>C.</i> sp. KIS-3. Both the nonreducing polyketide synthases (nrPKSs), and the regiospecific, fastidious <i>O-</i>methyltransferases (OMTs) are non-orthologous to their Ascomycete counterparts, suggesting a parallel evolutionary origin for the pathway in Basidiomycetes. The genes for the nrPKS and the OMTs are not all clustered in <i>Cortinarius</i>, revealing metabolic crosstalk among paralogous nrPKS biosynthetic gene clusters.</p><h3>Conclusions</h3><p>Heterologous biosynthesis of physcion and dermolutein in <i>Saccharomyces cerevisiae</i> opens the way to produce specific <i>Cortinarius</i> anthraquinones, and to modify these scaffolds to tune their chemistry towards their various applications.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-025-02625-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143489606","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":"Compatible traits of oleaginous Mucoromycota fungi for lignocellulose-based simultaneous saccharification and fermentation","authors":"Cristian Bolaño Losada,&nbsp;Ondrej Slaný,&nbsp;Dana Byrtusová,&nbsp;Boris Zimmermann,&nbsp;Svein Jarle Horn,&nbsp;Achim Kohler,&nbsp;Volha Shapaval","doi":"10.1186/s13068-025-02621-w","DOIUrl":"10.1186/s13068-025-02621-w","url":null,"abstract":"<div><h3>Background</h3><p>Mucoromycota fungi are promising for the production of second-generation biofuel from single-cell oils (SCOs) using lignocellulose biomass. Despite the lack of enzymatic capability for efficiently degrading lignocellulose in Mucoromycota fungi, simultaneous saccharification and fermentation (SSF) offers an attractive solution by combining enzymatic hydrolysis and fermentation in the same procedure. This study explored specific traits of various Mucoromycota species to evaluate their suitability for SSF, due to the frequent and significant gap between the microorganism and enzyme optimal conditions.</p><h3>Results</h3><p>The suitability of nine oleaginous fungal strains from the Mucoromycota phylum for use in lignocellulose-based simultaneous saccharification and fermentation was evaluated. Several traits, such as thermal tolerance, biochemical composition changes in response to incubation temperature, cellobiose and cellulose response and induction of β-glucosidase and endoglucanase, were evaluated. <i>Lichtheimia corymbifera</i> was the most suitable species for SSF due to its ability to grow up to 45 °C, with a consequent decrease in lipid unsaturation, and good uptake of cellobiose with induction of β-glucosidase and endoglucanase expression. The <i>Cunninghamella blackesleeana</i> and <i>Mucor circinelloides</i> strains were also considered good candidates; despite the cultivation should not exceed 35 °C, their good uptake of cellobiose and the expression of extracellular β-glucosidase induced by cellobiose indicated that they could increase the enzymatic hydrolysis efficiency. <i>C. blakesleeana</i> outperformed all the other tested strains in terms of β-glucosidase activity expression. In addition, both endoglucanase and β-glucosidase activities of <i>Rhizopus stolonifer</i> and <i>M. circinelloides</i> were induced by cellobiose. <i>Mortierella alpina</i> and <i>Mortierella hyalina</i> were not considered suitable for simultaneous saccharification and fermentation due to their reduced tolerance to high temperatures and poor response to cellobiose utilization.</p><h3>Conclusions</h3><p>This study identified beneficial traits of Mucoromycota species for simultaneous saccharification and fermentation using lignocellulose, contributing to an optimal selection for producing lipid-derived second-generation biofuels.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-025-02621-w","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143481243","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":"Seed-specific expression of phosphatidate phosphohydrolases increases soybean oil content and seed weight","authors":"Beibei Chen,&nbsp;Jianwu Li,&nbsp;Shuaibing Yao,&nbsp;Geliang Wang,&nbsp;Xuemin Wang","doi":"10.1186/s13068-025-02620-x","DOIUrl":"10.1186/s13068-025-02620-x","url":null,"abstract":"<div><h3>Background</h3><p>Soybean is a major oil crop and a primary protein source for livestock, and soybean oil is the most common input for biodiesel. Identifying genes that enhance soybean yield and oil content is crucial for breeding programs. Phosphatidic acid (PA) phosphohydrolase (PAH), which dephosphorylates PA to diacylglycerol (DAG), plays a critical role in lipid synthesis, and yet their potential in improving agronomic traits of oil crops remains unexplored.</p><h3>Results</h3><p>This study shows that seed-specific expression of <i>AtPAH1/2</i> enhances PA turnover into DAG and triacylglycerol (TAG) accumulation in soybean seeds. <i>PAH</i> overexpression upregulated the expression of DAG acyltransferase (<i>DGAT</i>) but suppressed phospholipid: DAG acyltransferase (<i>PDAT</i>). In addition, seed-specific expression of <i>AtPAH1/2</i> increases soybean seed size and weight. Furthermore, analysis of the variation of the soybean PAHs in 4414 soybean accessions indicated that the advantageous effects of <i>GmPAH</i>s on oil content and seed weight were selected during domestication.</p><h3>Conclusion</h3><p>These findings suggest that targeting <i>PAH</i>s represents a promising strategy for enhancing soybean seed oil content and yield in current cultivars and landraces soybeans.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-025-02620-x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143475294","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":"Target of Rapamycin is a crucial regulator of photosynthesis and nutrient metabolism partitioning in Nannochloropsis gaditana","authors":"Zhengying Zhang,&nbsp;Yanyan Li,&nbsp;Shu Yang,&nbsp;Shuting Wen,&nbsp;Hongmei Zhu,&nbsp;Hantao Zhou","doi":"10.1186/s13068-025-02617-6","DOIUrl":"10.1186/s13068-025-02617-6","url":null,"abstract":"<div><p>Utilizing microalgae as “photosynthetic cell factories” for compound production holds significant potential for sustainable carbon neutrality. However, the inherent inefficiency of algal photosynthesis, a limiting factor for productivity, represents a critical area for enhancement. Among the key regulatory mechanisms, the Target of Rapamycin (TOR), essential for cell growth regulation and known for its conserved structure across eukaryotes, remains underexplored in <i>Nannochloropsis gaditana</i>. In this study, we identified conserved component of the TOR complex in <i>N. gaditana</i>. Rapamycin (RAP) effectively inhibited photosynthetic growth and enhanced lipid accumulation in <i>N. gaditana</i>, as demonstrated by sensitivity tests. Transcriptomic analysis revealed that NgTOR modulates multiple intracellular metabolic and signaling pathways. Specifically, genes associated with photosynthesis and chlorophyll synthesis were significantly down-regulated following NgTOR inhibition. Additionally, genes involved in carbon metabolism, the TCA cycle, and amino acid biosynthesis were markedly reduced, while those related to lipid metabolism were up-regulated, resulting in stunted cell growth and increased lipid accumulation. Furthermore, blocking photosynthesis with DCMU significantly reduced the transcriptional activity of TOR-related complexes, highlighting a bidirectional regulatory interaction. These findings underscore the pivotal role of the TOR signaling pathway in regulating photosynthesis, carbon metabolism, and lipid metabolism in <i>N. gaditana</i>, setting the stage for further studies on photosynthetic autotrophy and lipid metabolic pathways in this species.</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/s13068-025-02617-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471945","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":"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}