Journal of microbiology and biotechnology最新文献

{"title":"Research Progress on Pharmacological Effects of Key Pharmacodynamic Material Basis Components of <i>Schisandrae chinensis</i> Fructus.","authors":"Hang Pan, Hongxuan Yu, Rui Liu, Liru Zhou, Zehua Wang, Qiong Liu, Guizhen Wang","doi":"10.4014/jmb.2602.02009","DOIUrl":"https://doi.org/10.4014/jmb.2602.02009","url":null,"abstract":"<p><p><i>Schisandra chinensis</i> Baill. and its dried ripe fruit, <i>Schisandrae chinensis</i> Fructus, are typical medicinal and edible resources in traditional Chinese medicine. Modern studies indicate that this medicinal material contains lignans, polysaccharides, volatile oils, triterpenoids, flavonoids, and other constituents, among which lignans are the most characteristic pharmacodynamic material basis. Based on the literature covered in this review, this paper summarizes the main bioactive components and structural features of <i>S. chinensis</i> and reviews the pharmacological evidence for antioxidation, anti-inflammatory activity, anti-tumor activity, sedative-hypnotic effects, hepatoprotection, neuroprotection, and metabolic regulation. The currently direct compound-specific evidence is relatively clearer for schisandrin B, schisandrol A/B, and schisanhenol in selected experimental models, whereas several other reported activities still rely mainly on extract-level studies, network pharmacology, or indirect inference. This review aims to provide an evidence-based reference for clarifying the pharmacodynamic material basis, improving quality evaluation, and guiding further mechanistic and clinical studies of <i>S. chinensis</i> Fructus.</p>","PeriodicalId":16481,"journal":{"name":"Journal of microbiology and biotechnology","volume":"36 ","pages":"e2602009"},"PeriodicalIF":3.4,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13481209/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148794401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular Access Engineering for Microbial Biocatalysis: from Enzyme Tunnels to Microbial Cell Factories.","authors":"Suk Min Kim","doi":"10.4014/jmb.2607.07018","DOIUrl":"10.4014/jmb.2607.07018","url":null,"abstract":"<p><p>Microbial biocatalysis spans biological platforms ranging from purified enzymes and multienzyme assemblies to electroenzymatic systems, whole-cell biocatalysts, and genetically programmable microbial cell factories. Yet despite their biological diversity, functional biocatalytic performance is often influenced by both catalytic activity and molecular accessibility. This recurring constraint highlights molecular accessibility as a common engineering consideration across microbial biocatalysis. Accordingly, this Review presents the concept of molecular access engineering as the rational control of molecular accessibility to improve functional biocatalytic performance across biological scales. The concept encompasses three complementary strategies governing molecular entry, intermediate transfer, and molecular exchange throughout biological systems. Examples from gas-converting enzymes, multienzyme assemblies, electroenzymatic systems, catalytic cascades, whole-cell biocatalysts, and microbial cell factories illustrate how engineering molecular accessibility can improve catalytic robustness, pathway efficiency, biological compatibility, and systems-level productivity. These examples therefore suggest that molecular access engineering has the potential to broaden the design space for microbial biocatalysis by complementing catalytic engineering.</p>","PeriodicalId":16481,"journal":{"name":"Journal of microbiology and biotechnology","volume":"36 ","pages":"e2607018"},"PeriodicalIF":3.4,"publicationDate":"2026-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13430250/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148604246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Key Safety Criteria for Novel Microbial Food Ingredients: A Comparative Analysis of International Regulatory Frameworks.","authors":"Yejin Choi, Ji-Seon Hwang, Hyunok Doo, Jinok Kwak, Juyoun Kang, Haram Kim, Yeongjae Chae, Suyoung Lee, Sheena Kim, Ju-Hoon Lee, Hyeun Bum Kim","doi":"10.4014/jmb.2605.05032","DOIUrl":"10.4014/jmb.2605.05032","url":null,"abstract":"<p><p>In the context of the research on food ingredients, \"novel microorganisms (NMs)\" refers to microorganisms without a documented history of safe consumption. The utilization of these novel microorganism-derived ingredients is expanding rapidly within the food and nutrition sectors, and such ingredients are broadly classified into three categories, live microorganisms, non-viable bacteria, and purified metabolites, each characterized by distinct risk profiles and unique regulatory requirements. Despite their growing prevalence, a globally harmonized protocol for safety assessment is currently lacking, leading individual nations to implement disparate safety frameworks within their respective regulatory systems. Consequently, this review aimed to provide a scientific foundation for the standardization of safety criteria by performing a comparative analysis of established guidelines from the European Union (EFSA), United States (FDA), Canada (Health Canada), Brazil (ANVISA), Thailand (Thai FDA), India (FSSAI), Japan (FSCJ), and Australia/New Zealand (FSANZ). Our analysis identified several universal safety parameters for live NMs, including hemolytic activity, antimicrobial resistance (AMR), toxigenic potential, the production of antimicrobial substances, metabolic profiling, and toxicological assessment. While toxicological evaluation, the production of antimicrobial substances, and the absence of live NMs were the consensus criteria for the safety evaluation of non-viable bacteria and purified microbial metabolites, an allergenicity evaluation is additionally required for purified microbial metabolites. Based on our analysis, this review proposed safety standards for novel microbial food ingredients including live microorganisms, non-viable bacteria, and purified metabolites by synthesizing these diverse regulatory landscapes.</p>","PeriodicalId":16481,"journal":{"name":"Journal of microbiology and biotechnology","volume":"36 ","pages":"e2605032"},"PeriodicalIF":3.4,"publicationDate":"2026-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13402210/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148578974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kimchi Probiotic <i>Weissella cibaria</i> Wikim0187 Attenuates Age-Related Muscle Loss: Association with Gut Microbiota Remodeling in Mice.","authors":"Sulhee Lee, Ga Hee Choi, Sang-Pil Choi, Namhee Kim, Young Seo Jang, Min-Sung Kwon, Young Joon Oh, Jeong Hyun Seo, Hwayeon Sun, Ji Ye Mok, Sang Min Park, Byungwook Lee, Hak-Jong Choi","doi":"10.4014/jmb.2607.07010","DOIUrl":"10.4014/jmb.2607.07010","url":null,"abstract":"<p><p>Sarcopenia, characterized by an age-related progressive decline in skeletal muscle mass and strength, is emerging as a major public health concern in aging societies. Despite growing insights into sarcopenia pathophysiology, effective and targeted therapeutic strategies for preventing or treating age-related muscle loss remain limited. Here, we aimed to examine the effects of <i>Weissella cibaria</i> Wikim0187, a probiotic strain isolated from kimchi, on age-related sarcopenia. Male C57BL/6J mice aged 18 months received oral administration of Wikim0187 (1 × 10⁹ CFU per mouse) for 4 months. Wikim0187 supplementation induced significant increases in gastrocnemius muscle mass and quadriceps muscle mass, absolute grip strength, and mean muscle fiber cross-sectional area. At the molecular level, MuRF-1 and Atrogin-1 expression was substantially reduced, whereas that of MyoD and Myogenin was markedly elevated, particularly in the quadriceps muscle. Western blot analysis confirmed a reduction in Atrogin-1 protein levels and an increase in phosphorylated Akt. In addition, gut microbiota analysis revealed significant alterations in microbial composition, with positive correlations between enriched bacterial taxa and improved clinical parameters. Taken together, these findings support the therapeutic potential of Wikim0187 as a safe and effective intervention for the prevention and treatment of sarcopenia in elderly populations.</p>","PeriodicalId":16481,"journal":{"name":"Journal of microbiology and biotechnology","volume":"36 ","pages":"e2607010"},"PeriodicalIF":3.4,"publicationDate":"2026-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13402211/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148579106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of HY7602-Fermented Deer Antler Extract on Selected Muscle-Related Outcomes and Fermentation-Associated Metabolomic Profiles.","authors":"Dong-Ki Hong, Soomin Jeon, Man Young Jo, Soo-Dong Park, Il-Dong Choi, Jae-Jung Shim, Do Yup Lee, Jae-Hwan Lee","doi":"10.4014/jmb.2604.04018","DOIUrl":"10.4014/jmb.2604.04018","url":null,"abstract":"<p><p>Age-related loss of muscle strength is closely associated with frailty, reduced mobility, and loss of independence. In this study, we investigated the clinical and metabolomic features of deer antler extract fermented with <i>Latilactobacillus curvatus</i> HY7602. A 12-week randomized, double-blind, placebo-controlled trial was conducted in adults with reduced muscle function to evaluate the effects of daily intake of the fermented extract on muscle-related outcomes and functional performance. In parallel, exploratory untargeted LC-MS/MS-based metabolomic profiling was performed to examine biochemical changes during fermentation at three stages: extract (E), HY7602-supplemented extract (L), and fermented extract (F). After 12 weeks, the fermented deer antler extract group showed improvements in selected muscle-related outcomes compared with the placebo group, including bilateral and unilateral hand grip strength, right quadriceps strength, and Short Physical Performance Battery chair-stand performance. Metabolomic profiling revealed stage-dependent differences among the three preparation stages. Principal component analysis showed distinct clustering of E, L, and F, with the largest separation observed between E and F. Trajectory analysis suggested progressive changes in polyamine-related metabolites, amino acid derivatives, and γ-glutamyl peptides. Pathway analysis further indicated coordinated differences in nitrogen and amine metabolism, polyamine metabolism, glutathione-related metabolism, nucleotide metabolism, and central carbon metabolism. HY7602-fermented deer antler extract may support selected strength-related outcomes in adults with reduced muscle function. Metabolomic profiling characterized the fermented product and provides a foundation for future mechanistic studies.</p>","PeriodicalId":16481,"journal":{"name":"Journal of microbiology and biotechnology","volume":"36 ","pages":"e2604018"},"PeriodicalIF":3.4,"publicationDate":"2026-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13442422/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148673713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative Evaluation of NR Locus-Targeted Nuclear Transformation in <i>Chlorella vulgaris</i> Using eGFP and Flow Cytometry.","authors":"Min-Kwan Sung, So-Hyeon Jo, Tae-Jin Choi","doi":"10.4014/jmb.2605.05007","DOIUrl":"10.4014/jmb.2605.05007","url":null,"abstract":"<p><p><i>Chlorella vulgaris</i> is a haploid green microalga with cost-effective cultivation, high biomass productivity, and heterotrophic growth capability, making it an attractive platform for food, pharmaceutical, and recombinant protein production. However, development of efficient nuclear transformation systems has been limited by its rigid cell wall and intrinsically low homologous recombination (HR) activity. Here, we established an antibiotic-free nuclear transformation strategy targeting the endogenous nitrate reductase (NR) locus in <i>C. vulgaris</i> PKVL7422 using donor constructs designed to promote homologous recombination. Transformation outcomes were quantitatively evaluated by flow cytometry based on GFP-positive frequency. A codon-optimized GFP expression cassette driven by the heterologous CaMV 35S promoter and terminated by the <i>RBCS2</i> 3' untranslated region was flanked by <i>NR</i> homology arms and introduced as linear donor DNA via electroporation. GFP-positive frequency was quantified by flow cytometry. GFP-positive cells were detected at frequencies of 5.1-6.3%. Optimization of homology arm length, donor DNA amount, and electroporation voltage enabled reproducible enrichment of targeted GFP integration events. Junction PCR confirmed precise insertion at the <i>NR</i> locus. Compared with previous reports, the GFP-positive frequencies observed in this study were substantially higher under our experimental conditions. Disruption of the endogenous <i>NR</i> gene enabled antibiotic-free selection based on nitrate metabolism, while GFP fluorescence allowed rapid quantitative screening. These results provide a basis for HR-mediated nuclear genome engineering and recombinant protein expression in <i>C. vulgaris</i>.</p>","PeriodicalId":16481,"journal":{"name":"Journal of microbiology and biotechnology","volume":"36 ","pages":"e2605007"},"PeriodicalIF":3.4,"publicationDate":"2026-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13430251/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148630567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anti-Cariogenic Potential of Lyophilized Cell-Free Supernatant of Probiotic <i>Pediococcus pentosaceus</i> GS4 against <i>Streptococcus mutans</i> and <i>Streptococcus anginosus</i>.","authors":"Sudaarsan Aruna Senthil Kumar, Asit Ranjan Ghosh","doi":"10.4014/jmb.2604.04005","DOIUrl":"10.4014/jmb.2604.04005","url":null,"abstract":"<p><p><i>Streptococcus</i> species, particularly <i>Streptococcus mutans</i> and <i>Streptococcus anginosus</i>, are recognized globally for their role in causing dental caries and other dental issues. Current treatments using fluoride products and conventional antibiotics are often ineffective due to the resilience of biofilms on tooth surfaces. To overcome these challenges, novel approaches that eliminate these pathogens are much needed. In this regard, we have prepared CFS (cell-free supernatant), a postbiotic preparation of our probiotic strain <i>Pediococcus pentosaceus</i> GS4, and investigated the anticariogenic properties of its lyophilized form (LCFS). A quantity of LCFS (400 mg/mL) demonstrated bactericidal, antibiofilm, and anti-caries properties against <i>S. mutans</i> and <i>S. anginosus</i>. The physiological effectiveness of the LCFS was assessed in a simulated artificial salivary fluid (ASF), which showed biofilm inhibition of more than and around 65% for single-pathogen biofilms and above 60% for both-species biofilms, whereas the biofilm formation was inhibited by more than 65% and 60%, respectively, in the growth medium (BHIB). Again, mature biofilm disruption was higher in ASF than in the growth medium. These observations were confirmed by using light microscopy, scanning electron microscopy, and confocal microscopy. Additionally, LCFS reduced the cariogenic properties of these pathogens by lowering acid tolerance, reducing EPS production, and increasing sensitivity to H₂O₂. These findings suggest that such a simple, functional postbiotic preparation could be a promising anticariogenic agent for treating dental caries.</p>","PeriodicalId":16481,"journal":{"name":"Journal of microbiology and biotechnology","volume":"36 ","pages":"e2604005"},"PeriodicalIF":3.4,"publicationDate":"2026-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13550011/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148900789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wound-Healing and Antibacterial Activities of <i>Caryopteris mongolica</i> Bunge Root Extract Ointment in an Experimental Animal Model.","authors":"Tuyajargal Iimaa, Tsenguun Tuyajargal, Namuunaa Ganbayar, Undarmaa Otgonbaatar, Stipan Nurbyek, Undrakhbayar Tserendorj, Soyolmaa Gurdorj, Altanchimeg Adilbish, Byambajav Tseesuren, Batkhuu Javzan, Davaapurev Bekh-Ochir","doi":"10.4014/jmb.2605.05002","DOIUrl":"https://doi.org/10.4014/jmb.2605.05002","url":null,"abstract":"<p><p><i>Caryopteris mongolica</i> Bunge is a medicinal plant native to Mongolia with a long history of use in traditional medicine for treating skin infections and inflammatory conditions. Recent phytochemical investigations have identified potent antibacterial constituents in its root extracts, particularly active against Gram-positive bacteria. The present study aimed to develop a novel topical ointment formulation incorporating ethanolic extract of <i>C. mongolica</i> roots, Vaseline, and lavender oil, and to evaluate both its antibacterial activity and wound-healing efficacy within an integrated experimental framework. Antibacterial activity was assessed using disk diffusion method against four Gram-positive strains (<i>Staphylococcus aureus</i>, <i>Staphylococcus epidermidis</i>, <i>Enterococcus faecalis</i>, and <i>Micrococcus luteus</i>). Activity was first observed at 3.0 mg/mL, and consistent inhibition at 5.0 mg/mL, which was selected as the working concentration. Physicochemical evaluation showed that all ointment parameters were within USP 30 standards, and microbiological testing indicated the absence of pathogenic contaminants. Wound-healing efficacy was evaluated using eight-week-old BALB/c mice randomly divided into three groups (n = 15 per group): untreated control, vehicle ointment control, and <i>C. mongolica</i> ointment-treated group. Topical application every two days for 14 days resulted in higher wound closure in the <i>C. mongolica</i>-treated group (97.1%) compared with vehicle (92.96%) and untreated (92.35%) controls. Statistically significant differences were observed during the early phase of healing (days 3 and 5; <i>p</i> < 0.05), whereas no significant differences were detected at later time points. Histopathological analyses showed improved epidermal regeneration (794.65 ± 75.27 μm vs. 394.59 ± 58.5 μm), granulation tissue thickness, collagen deposition, and neovascularization in treated wounds, along with minimal inflammatory cell infiltration by day 14. These findings suggest that <i>C. mongolica</i> root extract ointment is associated with antibacterial activity and improved wound-healing outcomes in an experimental animal model, though a direct causal relationship between these two properties was not established.</p>","PeriodicalId":16481,"journal":{"name":"Journal of microbiology and biotechnology","volume":"36 ","pages":"e2605002"},"PeriodicalIF":3.4,"publicationDate":"2026-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13481211/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148794417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Protective Effects of <i>Komagataeibacter rhaeticus</i> SLAM-JS1B Derived Metabolites in High-Fat Diet-Induced Obesity.","authors":"Daniel Junpyo Lee, Jiseong Mun, Youbin Choi, Min-Geun Kang, Anna Kang, Eunsol Seo, Seon-Hui Son, Sangnam Oh, Younghoon Kim","doi":"10.4014/jmb.2604.04041","DOIUrl":"10.4014/jmb.2604.04041","url":null,"abstract":"<p><p>This study aimed to investigate the anti-obesity properties of <i>Komagataeibacter rhaeticus</i> SLAM-JS1B derived metabolites, a bacterial strain isolated from kombucha. The effects were assessed in mice with obesity induced by a high-fat diet. Supplementation with <i>K. rhaeticus</i> SLAM-JS1B derived metabolites significantly attenuated body weight gain without altering food intake. Serum total cholesterol, triglyceride, and low-density lipoprotein levels were significantly reduced, together with improved indicators of hepatic damage. In addition, hepatic steatosis and adipose tissue accumulation were markedly attenuated. These metabolic improvements were linked to lower hepatic expression of genes related to lipogenesis and cholesterol production. In the colon, supplementation with <i>K. rhaeticus</i> SLAM-JS1B derived metabolites increased the expression of genes related to intestinal barrier integrity and lowered the expression of pro-inflammatory cytokine genes. Fecal metabolomic analysis further revealed increased fecal cholesterol excretion following <i>K. rhaeticus</i> SLAM-JS1B derived metabolites supplementation. Moreover, gut microbial composition was altered in a manner consistent with improved metabolic status. Collectively, these findings suggest that <i>K. rhaeticus</i> SLAM-JS1B derived metabolites may represent a promising dietary strategy for the prevention or management of obesity and related metabolic disorders, particularly in contexts where the use of live microorganisms is undesirable.</p>","PeriodicalId":16481,"journal":{"name":"Journal of microbiology and biotechnology","volume":"36 ","pages":"e2604041"},"PeriodicalIF":3.4,"publicationDate":"2026-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13430252/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148630217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Purification, Characterization, and Oil-Displacement Performance of Rhamnolipid Biosurfactant Produced by <i>Bacillus</i> sp. DQ-4.","authors":"Jing Wei, Xiaojun Sun, Liping Pang, Xin Shao, Di Yang, Hongrui Fu, Jinren Lu, Mutai Bao","doi":"10.4014/jmb.2601.01038","DOIUrl":"10.4014/jmb.2601.01038","url":null,"abstract":"<p><p>Rhamnolipids are attractive biosurfactants for enhanced oil recovery, but the commonly used producing strains may raise biosafety concerns. In this study, a rhamnolipid-producing isolate, designated <i>Bacillus</i> sp. DQ-4, was obtained from oily sludge and cultivated in a glucose-based fermentation medium. The purified product, DQ-Rha, was characterized by TLC, FTIR, MALDI-TOF MS, and 1D/2D NMR (¹H, ¹³C, ¹H-¹H COSY, ¹H-¹³C HSQC, and HMBC). The combined spectroscopic results were consistent with a rhamnolipid structure, and no obvious conflicting signals were detected. DQ-Rha reduced the surface tension to 33.4 mN/m, and the DQ-4 supernatant showed an oil-spreading diameter of 89.3 mm and an emulsification index of 72.3% against diesel. In oil-displacement-related evaluations, DQ-Rha gave an oil-washing efficiency of 54.62%. In etched micromodel experiments, the total recovery factor reached 60.06%, which was comparable to that of commercial rhamnolipid (59.53%). In core flooding experiments at 85°C, injection of DQ-Rha after primary water flooding further increased the recovery factor by 10.56%, again showing performance comparable to commercial rhamnolipid. Acute oral toxicity testing in ICR mice showed no mortality or obvious toxic symptoms at 5040.6 mg/kg, and the acute oral LD₅₀ was greater than 5000 mg/kg under the test conditions. These results suggested that DQ-Rha was a rhamnolipid biosurfactant with favorable oil-displacement-related performance and low acute oral toxicity.</p>","PeriodicalId":16481,"journal":{"name":"Journal of microbiology and biotechnology","volume":"36 ","pages":"e2601038"},"PeriodicalIF":3.4,"publicationDate":"2026-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13373720/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148456150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}