Biotechnology for Biofuels最新文献

{"title":"Enhancement of non-oleaginous green microalgae Ulothrix for bio-fixing CO2 and producing biofuels by ARTP mutagenesis","authors":"Mingshan Yin,&nbsp;Yuliang An,&nbsp;Feng Qi,&nbsp;Ruimin Mu,&nbsp;Guixia Ma,&nbsp;Feiyong Chen","doi":"10.1186/s13068-024-02577-3","DOIUrl":"10.1186/s13068-024-02577-3","url":null,"abstract":"<div><p>Oleaginous green microalgae are often mentioned in algae-based biodiesel industry, but most of them belong to specific genus (<i>Chlorella</i>, <i>Scenedesmus</i>, <i>Botryococcus</i> and <i>Desmodesmus</i>). Thus, the microalgal germplasm resources for biodiesel production are limited. Mutagenesis is regarded as an important technology for expanding germplasm resources. The main purpose of this study is to screen microalgae strains with high carbon dioxide tolerance and high lipid content from mutants derived from indigenous non-oleaginous green microalgae species—<i>Ulothrix</i> SDJZ-17. Two mutants with high CO₂ tolerance and high lipid content genetic stability were obtained from the mutants by high-throughput screening, named <i>Ulothrix</i> SDJZ-17-A20 and <i>Ulothri</i>x SDJZ-17-A23. In order to evaluate the potential of CO₂ fixation and biofuel production, A20 and A23 were cultured under air and 15% CO₂ (v/v) conditions, and their wild-type strains (WT) were used as controls. Under the condition of high CO₂ concentration, the growth performance and lipid production capacity of mutant strains A20 and A23 were not only significantly better than those of wild strains, but also better than those of their own cultured under air conditions. Among them, A23 obtained the highest LCE (light conversion efficiency) (14.79%), <i>Fv/Fm </i>(maximal photochemical efficiency of photosystem II) (71.04%) and biomass productivity (81.26 mg L⁻¹ d⁻¹), while A20 obtained the highest lipid content (22.45%). Both mutants can be used as candidate strains for CO₂ fixation and biofuel production. By ARTP (atmospheric and room temperature plasma) mutagenesis with high-throughput screening, the mutants with higher CO₂ tolerance, photosynthetic efficiency and lipid productivity can be obtained, even if they are derived from non-oleaginous microalgae, which is of great significance for enriching the energy microalgae germplasm bank, alleviating the global warming and energy crisis.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"17 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-024-02577-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142634232","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":"Correction: A high-throughput dual system to screen polyphosphate kinase mutants for efficient ATP regeneration in l-theanine biocatalysis","authors":"Hui Gao,&nbsp;Mengxuan Li,&nbsp;Qing Wang,&nbsp;Tingting Liu,&nbsp;Xian Zhang,&nbsp;Taowei Yang,&nbsp;Meijuan Xu,&nbsp;Zhiming Rao","doi":"10.1186/s13068-023-02390-4","DOIUrl":"10.1186/s13068-023-02390-4","url":null,"abstract":"","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"16 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10504775/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10307065","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":"Ethanol tolerance in engineered strains of Clostridium thermocellum","authors":"Daniel G. Olson,&nbsp;Marybeth I. Maloney,&nbsp;Anthony A. Lanahan,&nbsp;Nicholas D. Cervenka,&nbsp;Ying Xia,&nbsp;Angel Pech-Canul,&nbsp;Shuen Hon,&nbsp;Liang Tian,&nbsp;Samantha J. Ziegler,&nbsp;Yannick J. Bomble,&nbsp;Lee R. Lynd","doi":"10.1186/s13068-023-02379-z","DOIUrl":"10.1186/s13068-023-02379-z","url":null,"abstract":"<div><p><i>Clostridium thermocellum</i> is a natively cellulolytic bacterium that is promising candidate for cellulosic biofuel production, and can produce ethanol at high yields (75–80% of theoretical) but the ethanol titers produced thus far are too low for commercial application. In several strains of <i>C. thermocellum</i> engineered for increased ethanol yield, ethanol titer seems to be limited by ethanol tolerance. Previous work to improve ethanol tolerance has focused on the WT organism. In this work, we focused on understanding ethanol tolerance in several engineered strains of <i>C. thermocellum</i>. We observed a tradeoff between ethanol tolerance and production. Adaptation for increased ethanol tolerance decreases ethanol production. Second, we observed a consistent genetic response to ethanol stress involving mutations at the AdhE locus. These mutations typically reduced NADH-linked ADH activity. About half of the ethanol tolerance phenotype could be attributed to the elimination of NADH-linked activity based on a targeted deletion of <i>adhE</i>. Finally, we observed that rich growth medium increases ethanol tolerance, but this effect is eliminated in an <i>adhE</i> deletion strain. Together, these suggest that ethanol inhibits growth and metabolism via a redox-imbalance mechanism. The improved understanding of mechanisms of ethanol tolerance described here lays a foundation for developing strains of <i>C. thermocellum</i> with improved ethanol production.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"16 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2023-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10503014/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10267592","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":"Enhancement of hemostatic properties of Cyclotella cryptica frustule through genetic manipulation","authors":"Lulu Wang,&nbsp;Yan Sun,&nbsp;Ruihao Zhang,&nbsp;Kehou Pan,&nbsp;Yuhang Li,&nbsp;Ruibing Wang,&nbsp;Lin Zhang,&nbsp;Chengxu Zhou,&nbsp;Jian Li,&nbsp;Yun Li,&nbsp;Baohua Zhu,&nbsp;Jichang Han","doi":"10.1186/s13068-023-02389-x","DOIUrl":"10.1186/s13068-023-02389-x","url":null,"abstract":"<div><h3>Background</h3><p>The silicified cell wall of diatoms, also known as frustule, shows huge potential as an outstanding bio-nanomaterial for hemostatic applications due to its high hemostatic efficiency, good biocompatibility, and ready availability. As the architectural features of the frustule determine its hemostatic performance, it is of great interest to develop an effective method to modify the frustule morphology into desired patterns to further improve hemostatic efficiency.</p><h3>Results</h3><p>In this study, the gene encoding Silicalemma Associated Protein 2 (a silicalemma-spanning protein) of <i>Cyclotella cryptica</i> (<i>CcSAP2</i>) was identified as a key gene in frustule morphogenesis. Thus, it was overexpressed and knocked down, respectively. The frustule of the overexpress lines showed no obvious alteration in morphology compared to the wild type (WT), while the size, specific surface area (BET), pore volume, and pore diameter of the knockdown strains changed greatly. Particularly, the knockdown frustules achieved a more pronounced coagulation effect and in vivo hemostatic performance than the WT strains. Such observations suggested that silicalemma proteins are ideal genetic encoding targets for manipulating frustule morphology associated hemostatic properties. Furthermore, the Mantel test was adopted to identify the key morphologies associated with <i>C. cryptica</i> bleeding control. Finally, based on our results and recent advances, the mechanism of frustule morphogenesis was discussed.</p><h3>Conclusion</h3><p>This study explores a new strategy for enhancing the hemostatic efficiency of the frustule based on genetic morphology modification and may provide insights into a better understanding of the frustule morphogenesis mechanism.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"16 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2023-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10503012/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10268532","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 Thermoanaerobacterium AK17 for increased ethanol production in seaweed hydrolysate","authors":"Antoine Moenaert,&nbsp;Bryndís Bjornsdottir,&nbsp;Einar Baldvin Haraldsson,&nbsp;Leila Allahgholi,&nbsp;Anna Zieri,&nbsp;Isabella Zangl,&nbsp;Sigríður Sigurðardóttir,&nbsp;Jóhann Örlygsson,&nbsp;Eva Nordberg Karlsson,&nbsp;Ólafur H. Friðjónsson,&nbsp;Guðmundur Óli Hreggviðsson","doi":"10.1186/s13068-023-02388-y","DOIUrl":"10.1186/s13068-023-02388-y","url":null,"abstract":"<div><p>Sustainably produced renewable biomass has the potential to replace fossil-based feedstocks, for generation of biobased fuels and chemicals of industrial interest, in biorefineries. In this context, seaweeds contain a large fraction of carbohydrates that are a promising source for enzymatic and/or microbial biorefinery conversions. The thermoanaerobe <i>Thermoanaerobacterium</i> AK17 is a versatile fermentative bacterium producing ethanol, acetate and lactate from various sugars. In this study, strain AK17 was engineered for more efficient production of ethanol by knocking out the lactate and acetate side-product pathways. This was successfully achieved, but the strain reverted to acetate production by recruiting enzymes from the butyrate pathway. Subsequently this pathway was knocked out and the resultant strain AK17_M6 could produce ethanol close to the maximum theoretical yield (90%), leading to a 1.5-fold increase in production compared to the wild-type strain. Strain AK17 was also shown to successfully ferment brown seaweed hydrolysate from <i>Laminaria digitata</i> to ethanol in a comparatively high yield of 0.45 g/g substrate, with the primary carbon sources for the fermentations being mannitol, laminarin-derived glucose and short laminari-oligosaccharides. As strain AK17 was successfully engineered and has a wide carbohydrate utilization range that includes mannitol from brown seaweed, as well as hexoses and pentoses found in both seaweeds and lignocellulose, the new strain AK17_M6 obtained in this study is an interesting candidate for production of ethanol from both second and third generations biomass.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"16 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10496261/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10240120","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":"Sustainable production of photosynthetic isobutanol and 3-methyl-1-butanol in the cyanobacterium Synechocystis sp. PCC 6803","authors":"Hao Xie,&nbsp;Jarl Kjellström,&nbsp;Peter Lindblad","doi":"10.1186/s13068-023-02385-1","DOIUrl":"10.1186/s13068-023-02385-1","url":null,"abstract":"<div><h3>Background</h3><p>Cyanobacteria are emerging as green cell factories for sustainable biofuel and chemical production, due to their photosynthetic ability to use solar energy, carbon dioxide and water in a direct process. The model cyanobacterial strain <i>Synechocystis</i> sp. PCC 6803 has been engineered for the isobutanol and 3-methyl-1-butanol production by introducing a synthetic 2-keto acid pathway. However, the achieved productions still remained low. In the present study, diverse metabolic engineering strategies were implemented in <i>Synechocystis</i> sp. PCC 6803 for further enhanced photosynthetic isobutanol and 3-methyl-1-butanol production.</p><h3>Results</h3><p>Long-term cultivation was performed on two selected strains resulting in maximum cumulative isobutanol and 3-methyl-1-butanol titers of 1247 mg L⁻¹ and 389 mg L⁻¹, on day 58 and day 48, respectively. Novel <i>Synechocystis</i> strain integrated with a native 2-keto acid pathway was generated and showed a production of 98 mg isobutanol L⁻¹ in short-term screening experiments. Enhanced isobutanol and 3-methyl-1-butanol production was observed when increasing the <i>kivd</i>^<i>S286T</i> copy number from three to four. Isobutanol and 3-methyl-1-butanol production was effectively improved when overexpressing selected genes of the central carbon metabolism. Identified genes are potential metabolic engineering targets to further enhance productivity of pyruvate-derived bioproducts in cyanobacteria.</p><h3>Conclusions</h3><p>Enhanced isobutanol and 3-methyl-1-butanol production was successfully achieved in <i>Synechocystis</i> sp. PCC 6803 strains through diverse metabolic engineering strategies. The maximum cumulative isobutanol and 3-methyl-1-butanol titers, 1247 mg L⁻¹ and 389 mg L⁻¹, respectively, represent the current highest value reported. The significantly enhanced isobutanol and 3-methyl-1-butanol production in this study further pave the way for an industrial application of photosynthetic cyanobacteria-based biofuel and chemical synthesis from CO₂.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"16 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2023-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10492371/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10211823","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":"Functional characterization of fungal lytic polysaccharide monooxygenases for cellulose surface oxidation","authors":"Yann Mathieu,&nbsp;Olanrewaju Raji,&nbsp;Annie Bellemare,&nbsp;Marcos Di Falco,&nbsp;Thi Truc Minh Nguyen,&nbsp;Alexander Holm Viborg,&nbsp;Adrian Tsang,&nbsp;Emma Master,&nbsp;Harry Brumer","doi":"10.1186/s13068-023-02383-3","DOIUrl":"10.1186/s13068-023-02383-3","url":null,"abstract":"<div><h3>Background</h3><p>Microbial lytic polysaccharide monooxygenases (LPMOs) cleave diverse biomass polysaccharides, including cellulose and hemicelluloses, by initial oxidation at C1 or C4 of glycan chains. Within the Carbohydrate-Active Enzymes (CAZy) classification, Auxiliary Activity Family 9 (AA9) comprises the first and largest group of fungal LPMOs, which are often also found in tandem with non-catalytic carbohydrate-binding modules (CBMs). LPMOs originally attracted attention for their ability to potentiate complete biomass deconstruction to monosaccharides. More recently, LPMOs have been applied for selective surface modification of insoluble cellulose and chitin.</p><h3>Results</h3><p>To further explore the catalytic diversity of AA9 LPMOs, over 17,000 sequences were extracted from public databases, filtered, and used to construct a sequence similarity network (SSN) comprising 33 phylogenetically supported clusters. From these, 32 targets were produced successfully in the industrial filamentous fungus <i>Aspergillus niger</i>, 25 of which produced detectable LPMO activity. Detailed biochemical characterization of the eight most highly produced targets revealed individual C1, C4, and mixed C1/C4 regiospecificities of cellulose surface oxidation, different redox co-substrate preferences, and CBM targeting effects. Specifically, the presence of a CBM correlated with increased formation of soluble oxidized products and a more localized pattern of surface oxidation, as indicated by carbonyl-specific fluorescent labeling. On the other hand, LPMOs without native CBMs were associated with minimal release of soluble products and comparatively dispersed oxidation pattern.</p><h3>Conclusions</h3><p>This work provides insight into the structural and functional diversity of LPMOs, and highlights the need for further detailed characterization of individual enzymes to identify those best suited for cellulose saccharification versus surface functionalization toward biomaterials applications.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"16 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2023-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10486138/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10195545","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":"Engineering a marine microalga Chlorella sp. as the cell factory","authors":"Xinping Gu,&nbsp;Ying Deng,&nbsp;Aoqi Wang,&nbsp;Qinhua Gan,&nbsp;Yi Xin,&nbsp;Kalyanee Paithoonrangsarid,&nbsp;Yandu Lu","doi":"10.1186/s13068-023-02384-2","DOIUrl":"10.1186/s13068-023-02384-2","url":null,"abstract":"<div><p>The use of marine microalgae in industrial systems is attractive for converting CO₂ into value-added products using saline water and sunlight. The plant nature and demonstrated industrial potential facilitate <i>Chlorella</i> spp. as excellent model organisms for both basic research and commercial application. However, the transformation method has not been developed in marine <i>Chlorella</i> spp., thus genetic engineering is hindered in exploiting the industrial potentialities of these strains. In this study, we provided a transformation protocol for the marine <i>Chlorella</i> strain MEM25, which showed robust characteristics, including high production of proteins and polyunsaturated fatty acids in multiple cultivation systems over various spatial–temporal scales. We showed that transformants could be obtained in a dramatically time-saving manner (comparable to <i>Saccharomyces cerevisiae</i>) with four functional proteins expressed properly<i>.</i> The transgenes are integrated into the genome and can be successfully inherited for more than two years. The development of a marine <i>Chlorella</i> transformation method, in combination with the complete genome, will greatly facilitate more comprehensive mechanism studies and provide possibilities to use this species as chassis for synthetic biology to produce value-added compounds with mutual advantage in neutralization of CO₂ in commercial scales.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"16 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2023-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10485975/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10198317","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":"Biotechnologies for bulk production of microalgal biomass: from mass cultivation to dried biomass acquisition","authors":"Song Qin,&nbsp;Kang Wang,&nbsp;Fengzheng Gao,&nbsp;Baosheng Ge,&nbsp;Hongli Cui,&nbsp;Wenjun Li","doi":"10.1186/s13068-023-02382-4","DOIUrl":"10.1186/s13068-023-02382-4","url":null,"abstract":"<div><p>Microalgal biomass represents a sustainable bioresource for various applications, such as food, nutraceuticals, pharmaceuticals, feed, and other bio-based products. For decades, its mass production has attracted widespread attention and interest. The process of microalgal biomass production involves several techniques, mainly cultivation, harvesting, drying, and pollution control. These techniques are often designed and optimized to meet optimal growth conditions for microalgae and to produce high-quality biomass at acceptable cost. Importantly, mass production techniques are important for producing a commercial product in sufficient amounts. However, it should not be overlooked that microalgal biotechnology still faces challenges, in particular the high cost of production, the lack of knowledge about biological contaminants and the challenge of loss of active ingredients during biomass production. These issues involve the research and development of low-cost, standardized, industrial-scale production equipment and the optimization of production processes, as well as the urgent need to increase the research on biological contaminants and microalgal active ingredients. This review systematically examines the global development of microalgal biotechnology for biomass production, with emphasis on the techniques of cultivation, harvesting, drying and control of biological contaminants, and discusses the challenges and strategies to further improve quality and reduce costs. Moreover, the current status of biomass production of some biotechnologically important species has been summarized, and the importance of improving microalgae-related standards for their commercial applications is noted.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"16 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10466707/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10124969","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":"Whole genome sequencing and the lignocellulose degradation potential of Bacillus subtilis RLI2019 isolated from the intestine of termites","authors":"Gongwei Liu,&nbsp;Ke Zhang,&nbsp;Hanxuan Gong,&nbsp;Kaiyao Yang,&nbsp;Xiaoyu Wang,&nbsp;Guangchen Zhou,&nbsp;Wenyuan Cui,&nbsp;Yulin Chen,&nbsp;Yuxin Yang","doi":"10.1186/s13068-023-02375-3","DOIUrl":"10.1186/s13068-023-02375-3","url":null,"abstract":"<div><h3>Background</h3><p>Lignocellulosic biomass is the most abundant and renewable terrestrial raw material for conversion into bioproducts and biofuels. However, the low utilization efficiency of lignocellulose causes environmental pollution and resource waste, which limits the large-scale application of bioconversion. The degradation of lignocellulose by microorganisms is an efficient and cost-effective way to overcome the challenge of utilizing plant biomass resources. This work aimed to screen valuable cellulolytic bacteria, explore its molecular mechanism from genomic insights, and investigate the ability of the strain to biodegrade wheat straw.</p><h3>Results</h3><p><i>Bacillus subtilis</i> (<i>B. subtilis</i>) RLI2019 was isolated from the intestine of <i>Reticulitermes labralis</i>. The strain showed comprehensive enzyme activities related to lignocellulose degradation, which were estimated as 4.06, 1.97, 4.12, 0.74, and 17.61 U/mL for endoglucanase, β-glucosidase, PASC enzyme, filter paper enzyme, and xylanase, respectively. Whole genome sequencing was performed to better understand the genetic mechanism of cellulose degradation. The genome size of <i>B. subtilis</i> RLI2019 was 4,195,306 bp with an average GC content of 43.54%, and the sequence characteristics illustrated an extremely high probability (99.41%) as a probiotic. The genome contained 4,381 protein coding genes with an average GC content of 44.20%, of which 145 genes were classified into six carbohydrate-active enzyme (CAZyme) families and 57 subfamilies. Eight cellulose metabolism enzyme-related genes and nine hemicellulose metabolism enzyme-related genes were annotated by the CAZyme database. The starch and sucrose metabolic pathway (ko00500) was the most enriched with 46 genes in carbohydrate metabolism. <i>B. subtilis</i> RLI2019 was co-cultured with wheat straw for 7 days of fermentation, the contents of neutral detergent fiber, acid detergent fiber, hemicellulose, and lignin were significantly reduced by 5.8%, 10.3%, 1.0%, and 4.7%, respectively. Moreover, the wheat straw substrate exhibited 664.9 μg/mL of reducing sugars, 1.22 U/mL and 6.68 U/mL of endoglucanase and xylanase activities, respectively. Furthermore, the fiber structures were effectively disrupted, and the cellulose crystallinity was significantly reduced from 40.2% to 36.9%.</p><h3>Conclusions</h3><p>The complex diversity of CAZyme composition mainly contributed to the strong cellulolytic attribute of <i>B. subtilis</i> RLI2019. These findings suggest that <i>B. subtilis</i> RLI2019 has favorable potential for biodegradation applications, thus it can be regarded as a promising candidate bacterium for lignocellulosic biomass degradation.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"16 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2023-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10439612/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10050566","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}