Journal of microbiology and biotechnology最新文献

{"title":"Comparative Effects of <i>Leuconostoc lactis</i> and <i>Leuconostoc mesenteroides</i> Starters on Kimchi Fermentation Dynamics and Metabolite Profiles.","authors":"Yura Moon, Sojeong Heo, Gawon Lee, Junghyun Park, Seung-Eun Oh, Sumin Lee, Minkyeong Kim, Do-Won Jeong","doi":"10.4014/jmb.2609.09002","DOIUrl":"10.4014/jmb.2609.09002","url":null,"abstract":"<p><p>This study evaluated the effects of two <i>Leuconostoc</i> starter-<i>Leuconostoc</i> (<i>Leu.</i>) <i>lactis</i> DMLL10 and <i>Leu. mesenteroides</i> KACC 12312^T-on kimchi fermentation characteristics, microbial dynamics, and metabolite production. Kimchi samples were fermented at 4°C for 20 days, and changes in pH, titratable acidity, viable cell counts, organic acids, amino acids, and volatile compounds were analyzed using GC-MS, HPLC, and multivariate statistical methods. Both starters successfully initiated fermentation, but clear differences in metabolic patterns were observed. <i>Leu. lactis</i> DMLL10-inoculated kimchi showed a lower relative abundance of <i>Latilactobacillus sakei</i>, a homofermentative LAB associated with excessive acidification, than the control. Compared with <i>Leu. mesenteroides</i>, <i>Leu. lactis</i> DMLL10-inoculated kimchi showed a relatively lower final titratable acidity and generated a broader range of organic acids, amino acids, and volatile compounds. In particular, it produced higher levels of glutamic acid, contributing to umami taste, as well as unique volatiles such as octanoic acid and specific aldehydes, enhancing flavor complexity. In contrast, <i>Leu. mesenteroides</i> KACC 12312^T showed faster acidification and a comparatively narrower metabolite profile. Multivariate and correlation analyses (PCA, OPLS-DA, and network mapping) revealed distinct fermentation patterns between the two tested starter strains. These findings support <i>Leu. lactis</i> DMLL10 as a promising alternative starter candidate for diversifying kimchi fermentation profiles, although further studies using multiple strains are required to determine whether the observed differences are species-specific or strain-dependent differences.</p>","PeriodicalId":16481,"journal":{"name":"Journal of microbiology and biotechnology","volume":"36 ","pages":"e2609002"},"PeriodicalIF":3.4,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13655590/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149109838","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":"Isolation and Characterization of <i>Levilactobacillus brevis</i> FBL-3 from Godeulppaegi Kimchi and Screening of Medium Components for γ-Aminobutyric Acid Production.","authors":"Eun-Ju Jang, Veeranjaneya Reddy Lebaka, Young-Min Kim, Young-Jung Wee","doi":"10.4014/jmb.2608.08011","DOIUrl":"10.4014/jmb.2608.08011","url":null,"abstract":"<p><p><i>γ</i>-Aminobutyric acid (GABA) is an amino acid with a variety of biological functions and is now becoming an essential food ingredient. In this work, a GABA-producing lactic acid bacterium was isolated from godeulppaegi kimchi and characterized by phenotypic, biochemical and molecular parameters. The isolate was identified as FBL-3, which produced acid colonies in MRS agar containing CaCO₃ and L-glutamic acid, was Gram positive, catalase-negative and rod-shaped, and had 99.1% similarity to <i>Levilactobacillus brevis</i> by API 50 CHL analysis and 100% 16S rRNA gene sequence similarity to <i>Lvb. brevis</i> ATCC 14869. Further, sequence analysis of 16S rRNA gene confirmed that it was <i>Lvb. brevis</i> FBL-3. The effects of carbon source, nitrogen source, and L-glutamic acid concentration on cell growth and TLC-densitometrically estimated GABA production were evaluated sequentially using a one-factor-at-a-time approach. Of the carbon sources tested, xylose had the highest GABA production (12.2 ± 2.34 g/L) and dry cell weight (0.75 ± 0.00 g/L) and 10 g/L xylose was selected as a good concentration for GABA production. Yeast extract was the most promising for nitrogen sources producing 4.65 ± 0.45 g/L GABA, and 20 g/L yeast extract was selected as a practical concentration since it produced 9.12 ± 1.48 g/L GABA with lower nitrogen input than 50 g/L yeast extract. L-Glutamic acid was a necessary precursor to GABA production. Although the highest GABA titer in the L-glutamic acid concentration experiment was found for 50 g/L L-glutamic acid (19.6 ± 1.03 g/L), 10 g/L L-glutamic acid supported the highest cell growth and was considered as a more balanced precursor.</p>","PeriodicalId":16481,"journal":{"name":"Journal of microbiology and biotechnology","volume":"36 ","pages":"e2608011"},"PeriodicalIF":3.4,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13673089/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149182481","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":"Dual Evidence of <i>Trichoderma pleuroti</i> Antagonism against <i>Pleurotus pulmonarius</i>: Direct Inhibition and Volatile-Mediated Bioassays with Volatilome Fingerprinting.","authors":"Wan Swan Shan, Kah Hin Low, Yingying Wu, Yee Shin Tan","doi":"10.4014/jmb.2605.05010","DOIUrl":"10.4014/jmb.2605.05010","url":null,"abstract":"<p><p><i>Trichoderma</i> is known to cause green mold contamination, which severely threatens <i>Pleurotus pulmonarius</i> cultivation in tropical regions, including Malaysia, and can lead to major yield and economic losses. In this study, the contact-dependent and contactless antagonistic interactions between <i>Trichoderma pleuroti</i> and <i>P. pulmonarius</i> were investigated, and associated morphological changes and volatile profiles were characterized. Dual-culture assays recorded rapid overgrowth of <i>P. pulmonarius</i> by <i>T. pleuroti</i>, leading to growth suppression and mycelial discoloration. Light and scanning electron microscopy demonstrated aggressive mycoparasitism in <i>T. pleuroti</i>, which showed hyphal deformation and specialized structure attachment at the interaction interface. Inverted and tripartite plate methods were used to evaluate volatile-mediated effects. In <i>P. pulmonarius</i>, exposure to <i>T. pleuroti</i> volatiles induced abnormal mycelial thickening and growth inhibition, consistent with a contribution of fungal volatiles to contactless antagonism. Headspace gas chromatography-ion mobility spectrometry revealed distinct volatilome patterns and identified several candidate VOC features associated with <i>T. pleuroti</i>, including 1-octanol, 1-octen-3-ol, 3-octanol, (E)-2-hexenal, (E)-2-heptenal, (E)-2-octenal, acetic acid and butanoic acids. Overall, <i>T. pleuroti</i> exhibited both contact-dependent and contactless antagonistic effects against <i>P. pulmonarius</i> mycelium, involving mycoparasitic interactions and volatile-mediated inhibition. These findings provide insights into the development of green mold disease in <i>Pleurotus</i> cultivation and contribute to a better understanding of fungus-fungus interactions in mushroom production.</p>","PeriodicalId":16481,"journal":{"name":"Journal of microbiology and biotechnology","volume":"36 ","pages":"e2605010"},"PeriodicalIF":3.4,"publicationDate":"2026-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13669513/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149168825","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":"Predatory Mechanisms of Myxobacteria and Their Potential in the Development of Biocontrol Agents.","authors":"Bongsoo Lee","doi":"10.4014/jmb.2608.08010","DOIUrl":"10.4014/jmb.2608.08010","url":null,"abstract":"<p><p>Climate change, environmental degradation, and the depletion of finite resources are intensifying the search for sustainable, bio-based solutions across agriculture, environmental management, and chemical production. Against this backdrop, myxobacteria have emerged as a valuable but still underused microbial resource, distinguished by their ecological versatility, multicellular behavior, predatory lifestyle, and biosynthetic capacity. This review integrates the mechanistic basis of myxobacterial predation with its translational potential in biocontrol, linking microbial ecology to applied biotechnology. The available evidence indicates that predation is not a single process but a coordinated program built from swarm behavior, gliding motility, contact-dependent killing, secreted hydrolytic enzymes, outer membrane vesicle (OMV)-mediated interference, nutrient competition, and specialized metabolites. Through these layers, myxobacteria antagonize phylogenetically diverse targets, including bacteria, fungi, oomycetes, and ciliates, with more limited evidence extending to cyanobacteria and nematodes. Unlike recent reviews that address either the cellular and genetic mechanisms of predation or antagonism against plant pathogens in isolation, this review connects mechanism with application and compares the maturity of the available evidence across target classes. Within this framework, selected bacterial and fungal plant-disease systems have field-level support; oomycetes are mechanistically well supported but have limited field validation; ciliates provide direct mechanistic predation evidence without biocontrol validation; cyanobacteria remain emerging with laboratory-based evidence; and nematodes remain preliminary, with evidence restricted to <i>in vitro</i> studies using <i>Caenorhabditis elegans</i>. Myxobacteria therefore merit continued investigation not only as model organisms for microbial ecology and natural product discovery but also as multifunctional platforms for sustainable biocontrol and broader biotechnological applications.</p>","PeriodicalId":16481,"journal":{"name":"Journal of microbiology and biotechnology","volume":"36 ","pages":"e2608010"},"PeriodicalIF":3.4,"publicationDate":"2026-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13669512/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149127790","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":"<i>Lactobacillus helveticus</i> HY7801 Attenuates Inflammatory Edema and Vascular Leakage while Modulating Endothelial Barrier Responses.","authors":"Daehyeop Lee, Haeryn Jeong, Hyeonjun Gwon, Jimin Baik, Joo-Yun Kim, Jae-Jung Shim, Jae-Hwan Lee","doi":"10.4014/jmb.2608.08031","DOIUrl":"10.4014/jmb.2608.08031","url":null,"abstract":"<p><p>Tissue edema results from excessive interstitial fluid accumulation driven by inflammatory responses and increased vascular leakage. This study investigated the protective effects of <i>Lactobacillus helveticus</i> HY7801 (HY7801) against inflammatory activation, endothelial barrier dysfunction, and edema formation <i>in vitro</i> and <i>in vivo</i>. In lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages, HY7801 reduced nitrite accumulation and <i>iNOS</i> expression. In tumor necrosis factor-α (TNF-α)-stimulated human umbilical vein endothelial cells (HUVECs), HY7801 increased nitrite accumulation and <i>eNOS</i> expression, suppressed the expression of endothelial adhesion molecules (<i>ICAM1</i>, <i>VCAM1</i>, and <i>SELE</i>) and <i>CXCL8</i>, and enhanced the expression of the tight junction-associated genes (<i>TJP1</i> and <i>CLDN5</i>). Furthermore, HY7801 partially restored transendothelial electrical resistance (TEER), an indicator of endothelial barrier integrity, following TNF-α-induced impairment. In a λ-carrageenan-induced mouse paw edema model, HY7801 treatment attenuated paw swelling, histological tissue thickening, and vascular leakage. These effects were accompanied by increased junction-associated gene expression in inflamed paw tissue and reduced circulating inflammatory mediators. Based on these anti-inflammatory and endothelial barrier-protective effects, HY7801-derived extracellular vesicles (HY7801 EVs) were further evaluated <i>in vitro</i> as a candidate bioactive component of HY7801. HY7801 EVs enhanced <i>TJP1</i> and <i>CLDN5</i> expression while suppressing <i>ICAM1</i>, <i>VCAM1</i>, and <i>SELE</i> expression. Collectively, our findings suggest that HY7801 attenuates inflammation-associated tissue edema and vascular leakage through coordinated modulation of inflammatory and endothelial barrier responses, and support a potential role for HY7801 EVs as a bioactive component contributing to these effects.</p>","PeriodicalId":16481,"journal":{"name":"Journal of microbiology and biotechnology","volume":"36 ","pages":"e2608031"},"PeriodicalIF":3.4,"publicationDate":"2026-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13630528/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149016964","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":"High-Yield and High-Titer Production of Levulinic Acid from Red Macroalgae via Sulfuric Acid-Catalyzed Hydrolysis: Optimization by Response Surface Methodology and Application to Actual Biomass.","authors":"Im Su Kang, Seon Hui Kim, Jun Hee Jang, Kyoung Heon Kim, Dong Hyun Kim","doi":"10.4014/jmb.2606.06033","DOIUrl":"10.4014/jmb.2606.06033","url":null,"abstract":"<p><p>Levulinic acid (LA) is a versatile bio-based platform chemical with wide-ranging applications in biofuels, solvents, and biodegradable materials. To establish an efficient LA production strategy, red macroalgae were selected as the biomass feedstock due to their high carbohydrate content-particularly galactan, which is rich in 3,6-anhydro-L-galactose (AHG), a sugar that readily converts to LA under acidic conditions. In this study, a response surface methodology (RSM) based on a Box-Behnken design was used to optimize LA production from agar, the primary polysaccharide in red algae. The RSM model predicted an optimum of 172.5°C, 67.4 min, 8% H₂SO₄, with a predicted LA yield of 32.45%, and independent experimental validation under these conditions resulted in an LA yield of 33.23%. The validated reaction conditions were subsequently applied to two species of red macroalgae, <i>Gracilaria verrucosa</i> and <i>Gelidium amansii</i>. At 1% (w/v) biomass loading, carbohydrate-based LA yields of 52.9% and 48.4% were obtained, with corresponding titers of 3.1 and 3.0 g/L, respectively. Increasing the biomass loading to 25% (w/v) increased the LA titers to 49.8 and 48.6 g/L, while the corresponding carbohydrate-based yields decreased to 34.6% and 31.3%, respectively. These findings highlight the potential of high-solids processing as a practical approach for LA production from marine biomass and provide a basis for further process development toward sustainable biorefinery applications.</p>","PeriodicalId":16481,"journal":{"name":"Journal of microbiology and biotechnology","volume":"36 ","pages":"e2606033"},"PeriodicalIF":3.4,"publicationDate":"2026-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13630533/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149069613","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":"Evaluation of Antimicrobial Activity, Toxicity, and Stability of <i>Andrographis paniculata</i> Intimate Wash Formulation.","authors":"Nur Rina Alissa Razian, Anis Amiera Muhamad Alojid, Khong Ling Huey, Tuan Nadrah Naim Tuan Ismail, Tuan Noorkorina Tuan Kub","doi":"10.4014/jmb.2602.02037","DOIUrl":"10.4014/jmb.2602.02037","url":null,"abstract":"<p><p>Vaginal infections are commonly treated with antibiotics but increasing antimicrobial resistance and side effects of commercial intimate wash have encouraged the search for safer herbal alternatives. This study aimed to develop and evaluate an intimate wash formulated with <i>Andrographis paniculata</i> extract against selected pathogens; <i>Candida albicans</i>, <i>Neisseria gonorrhoeae</i>, <i>Escherichia coli</i> and <i>Streptococcus agalactiae</i>. The antimicrobial activity of <i>A. paniculata</i> intimate wash was assessed by using the agar well diffusion method to observe inhibition zones. Toxicity evaluations were conducted, including heavy metal detection for the intimate wash and the brine shrimp lethality assay for the extract. Stability and sterility testing of intimate wash were also conducted to determine the product's shelf-life. The results showed that the intimate wash exhibited optimum inhibition at 3.125 mg/mL. Heavy metals were below the permissible limits, and the extract also demonstrated non-cytotoxic effect towards brine shrimp. The intimate wash showed good stability and remained free from contamination throughout 24 months of storage. In conclusion, <i>A. paniculata</i> intimate wash is acceptable for preliminary safety findings and has potential as herbal alternative for the management of vaginal infections. However, further <i>in vivo</i> and clinical studies are required to confirm its safety and efficacy.</p>","PeriodicalId":16481,"journal":{"name":"Journal of microbiology and biotechnology","volume":"36 ","pages":"e2602037"},"PeriodicalIF":3.4,"publicationDate":"2026-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13669509/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149127812","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":"Dietary <i>Magnolia kobus</i> DC. Attenuates Age-Associated Hippocampal Alterations in Mice in Association with Modulation of Iron Metabolism- and Ferroptosis-Related Markers.","authors":"Jong Min Kim, Hyun-Jin Na, Yiseul Kim, Sang-Hee Lee, Mi Jeong Sung","doi":"10.4014/jmb.2606.06032","DOIUrl":"10.4014/jmb.2606.06032","url":null,"abstract":"<p><p>Brain aging is a major contributor to cognitive decline and neurodegenerative disorders. Ferroptosis, a regulated form of cell death driven by iron-dependent lipid peroxidation, has emerged as a key mechanism associated with age-related hippocampal dysfunction. Here, we investigated whether dietary supplementation of <i>Magnolia kobus</i> DC. (MO) attenuates age-related hippocampal alterations in mice in association with changes in iron metabolism- and ferroptosis-related markers. Behavioral tests combined with molecular and histological analyses of hippocampal tissues from young and aged mice demonstrated that MO significantly attenuated age-associated behavioral alterations, including Y-maze spontaneous alternation performance, and modulated age-related molecular and histological alterations in the hippocampus. MO supplementation was associated with reduced expression of cellular senescence and neuroinflammatory markers and modulation of blood-brain barrier-associated tight junction proteins. Furthermore, MO supplementation was associated with partial normalization of age-associated alterations in iron metabolism-related proteins and modulation of ferroptosis-related markers, including lipid peroxidation-related markers. MO supplementation was also associated with increased cholinergic and synaptic protein expression and lower β-amyloid-related immunoreactivity and p-Tau (Ser404) levels in the aged hippocampus. These findings suggest that dietary MO attenuates age-associated hippocampal dysfunction in association with modulation of iron metabolism- and ferroptosis-related markers, highlighting its potential as a functional dietary intervention for promoting healthy brain aging.</p>","PeriodicalId":16481,"journal":{"name":"Journal of microbiology and biotechnology","volume":"36 ","pages":"e2606032"},"PeriodicalIF":3.4,"publicationDate":"2026-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13630537/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149016982","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":"Correction to: <i>Vibrio phycocola</i> sp. nov. and <i>Vibrio phycohabitans</i> sp. nov., Isolated from the Phycosphere of Marine Algae.","authors":"Jeong Min Kim, Byeong Jun Choi, Hülya Bayburt, Jae Kyeong Lee, Ju Hye Baek, Baolei Jia, Che Ok Jeon","doi":"10.4014/jmb.2026.3605.C05","DOIUrl":"10.4014/jmb.2026.3605.C05","url":null,"abstract":"","PeriodicalId":16481,"journal":{"name":"Journal of microbiology and biotechnology","volume":"36 ","pages":"e36005"},"PeriodicalIF":3.4,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13558041/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148911997","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":"Non-Proliferative Immune Restoration by <i>Euglena gracilis</i> EK Powder in Cyclophosphamide-Induced Immunosuppressed Mice.","authors":"Seung Woo Ahn, Yun Hwan Park, Chang Ho Cho, Seung Woo Jo, Mi Gyeong Lee, Yoon-E Choi","doi":"10.4014/jmb.2607.07031","DOIUrl":"10.4014/jmb.2607.07031","url":null,"abstract":"<p><p>Cytotoxic chemotherapy frequently induces immunosuppression, impairing the innate cellular and humoral immune responses. Therefore, immunomodulatory agents that restore immune function without indiscriminate leukocyte expansion are required. This study examined whether <i>Euglena gracilis</i> EK powder (EKP), a paramylon-rich β-1,3-glucan preparation, supports immune recovery under cyclophosphamide (CPA)-induced immunosuppression. Male BALB/c mice received EKP (80, 200, or 500 mg/kg/day for 21 days) under a dual-temporal CPA design: acute phase (days 7 and 9) and established phase (days 14 and 17). The immune status was assessed using peripheral hematology, splenocyte viability, cytokine profiling, natural killer (NK) cell-associated activity, serum immunoglobulin levels, and splenic histopathology. EKP did not restore the peripheral leukocyte counts in either model, indicating that its immunological effects were independent of hematopoietic recovery. However, EKP treatment improved the levels of functional immune markers in a dose-dependent manner. EKP increased basal splenocyte viability without enhancing mitogen-induced proliferation, restored IFN-γ and TNF-α production, and suppressed excessive IL-6 levels. NK cell-associated activity recovered across all EKP doses (<i>p</i> < 0.05-0.01), consistent with the increase in IL-12 p70 levels at the highest dose. Serum IgG levels were restored at all doses (<i>p</i> < 0.05-0.01); however, IgM and IgA showed class-specific recovery at 200 and 500 mg/kg, respectively, with IgA recovery suggesting possible gut-associated lymphoid tissue involvement. Splenic histopathology confirmed the dose-dependent recovery of white pulp organization and germinal center formation. These findings support a framework wherein EKP improves immune functional markers by preserving existing immune components and cytokine rebalancing, rather than increasing circulating leukocytes.</p>","PeriodicalId":16481,"journal":{"name":"Journal of microbiology and biotechnology","volume":"36 ","pages":"e2607031"},"PeriodicalIF":3.4,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13655588/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149110565","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}