Systems Microbiology and Biomanufacturing
·
2021
·Vol. 2
·期 3
·473-486
·
IF 0
Wu Aiai,Bai Yajun,Fan TaiPing,Zheng Xiaohui,Cai Yujie
l -Lactate dehydrogenases can reduce alpha-keto carboxylic acids asymmetrically and generally have a broad substrate spectrum. l -Lactate dehydrogenase gene (LF- l -LDH0845) with reducing activity towards 3,4-dihydroxyphenylpyruvate and phenylpyruvate was obtained from Lactobacillus fermentum JN248. To change the substrate specificity of LDH0845 and improve its catalytic activity towards large substrates, site-directed mutation of Tyr221 was performed by analyzing the amino acids in the active center. Kinetic parameters show that the k cat values of Y221F mutant on 3,4-dihydroxyphenylpyruvate, 4-methyl-2-oxopentanoate, and glyoxylate are 1.21 s −1 , 1.35 s −1 , and 0.72 s −1 , respectively, which are 420%, 150% and 130% of the wild-type LDH0845. This study shows that the mutations of Y221 can significantly change the substrate specificity of LDH0845, making it become a potential tool enzyme for the reduction of alpha-keto carboxylic acids with large functional groups.
研究领域:
生物化学
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分子生物学
·
酶工程
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DOI
Frontiers in Nutrition
·
2022
·
IF 6.59
Weifang Wang,Yunfeng Li,Guojing Han,Aimin Li,Xiaomei Kong
Background Asthma is a chronic disease, which is harmful to the health of the body and the quality of life. Supplementation of Lactobacillus can affect the immune environment of the lungs through the gut-lung axis. This study aimed to explore the potential regulatory targets of Lactobacillus to relieve inflammation in asthma and determine a new approach for improving asthma. Methods A mouse ovalbumin (OVA)-induced model was constructed. OVA mice were supplemented with Lactobacillus fermentum CECT5716 by gavage. The gut microbiota composition of normal and OVA mice was analyzed using 16S ribosomal DNA identification. BALF, serum, lung tissues, and duodenal tissues were collected. Wright’s staining was performed to determine the cell content of the alveolar lavage fluid. Hematoxylin-eosin staining, Masson staining, and periodic acid-Schiff staining were performed to observe the improvement in the lungs of OVA mice supplemented with Lactobacillus . Immunofluorescence was performed to measure the severity of the intestinal barrier leakage. Enzyme-linked immunosorbent assay was carried out to determine the expression levels of inflammatory cell factors, while quantitative reverse transcription-polymerase chain reaction and western blotting were performed to detect the levels of toll-like receptor 2 (TLR2)/TLR4 expression and cell adhesion factors. Results Compared with Control mice, OVA mice exhibited malignant conditions, such as intestinal leakage and lung edema. After supplementation with Lactobacillus , the inflammatory cell content in the bronchoalveolar lavage fluid decreased, and the inflammatory response was alleviated. The level of TLR2/TLR4 expression was reduced. The inflammatory cell infiltration in the airway mucosa of OVA mice was improved, alveolar swelling was reduced and the basement membrane appeared thinner. Conclusion The Lactobacillus inhibited the TLR2/TLR4 expression in OVA mice. Supplementation with Lactobacillus can alleviate the inflammatory response in OVA mice, inhibit pulmonary fibrosis, and treat asthma.
研究领域:
免疫学
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微生物学
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呼吸病学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
Foods
·
2024
·Vol. 13
·期 8
·1183
·
IF 4.7
Qin Li,Ke Xiao,Chi Yi,Fan Yu,Wenyue Wang,Junhui Rao,Menglin Liu,Lin Zhang,Yang Mu,Chao Wang,Qian Wu,Dongsheng Li,Mengzhou Zhou
Lactobacillus fermentum(L. fermentum) was first evaluated as a potential advanced glycation end-product (AGE) formation inhibitor by establishing a bovine serum albumin (BSA) + glucose (glu) glycation model in the present study. The results showed that the highest inhibition rates of pentosidine and total fluorescent AGEs byL. fermentumwere approximately 51.67% and 77.22%, respectively, which were higher than that of aminoguanidine (AG). Mechanistic analysis showed thatL. fermentumcould capture methylglyoxal and glyoxal, inhibit carbonyl and sulfhydryl oxidation, reduce the binding of glucose and amino groups, increase total phenolic content and antioxidant activity, and release intracellular substances to scavenge free radicals; these abilities were the basis of the antiglycation mechanism ofL. fermentum. In addition,L. fermentumsignificantly prevented conformational changes in proteins during glycation, reduced protein cross-linking by 35.67%, and protected the intrinsic fluorophore. Therefore, the inhibition ofL. fermentumon glycation mainly occurs through antioxidation, the capture of dicarbonyl compounds, and the protection of the BSA structure. These findings collectively suggest thatLactobacillusis an inhibitor of protein glycation and AGE formation and has the potential for nutraceutical applications.
研究领域:
食品科学
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生物化学
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DOI
PubMed
高影响因子
Frontiers in Nutrition
·
2021
·
IF 6.576
Yang Dongting,Lyu Wentao,Hu Ziyi,Gao Jiting,Zheng Zhiyao,Wang Weijun,Firrman Jenni,Ren Daxi
Hypercholesteremia or high cholesterol is one of the important factors leading to atherosclerosis and other cardiovascular diseases. The application of probiotics with cholesterol-lowering characteristics has become increasingly popular over the past decade due to their contribution to human health. This study aimed to evaluate the probiotic effects of Lactobacillus fermentum ZJUIDS06 and Lactobacillus plantarum ZY08 on hyperlipidemic golden hamsters. A hyperlipidemic model was established through a high cholesterol diet in golden hamsters, after which lyophilized Lactobacillus fermentum ZJUIDS06 and Lactobacillus plantarum ZY08 were orally administered individually for 8 weeks. The physiological characteristics of golden hamsters and short chain fatty acid (SCFA) in the colon were assessed by automatic Biochemical Analyzer and gas choromatograph, respectively. A MiSeq sequencing-based analysis of the bacterial 16S rRNA gene (V3–V4 region) in the cecum content was performed to analyze the cecum microbiota. Correlations between sets of these variables were also investigated using the R package “corrplot.” Results showed that neither Lactobacillus fermentum ZJUIDS06 nor Lactobacillus plantarum ZY08 inhibited body weight increase. However, supplementation with Lactobacillus fermentum ZJUIDS06 for 8 weeks increased colon SCFA levels (P < 0.05), decreased serum low-density lipoprotein, total cholesterol, and triglycerides levels, and also induced changes in the cecum microbiota of hyperlipidemic golden hamsters. Remarkably, oral administration of Lactobacillus fermentum ZJUIDS06 increased the relative abundance of Parabacteroides in the cecum, which served as a biomarker for colon SCFA production and improvement of serum cholesterol levels. In a word, Lactobacillus fermentum ZJUIDS06 improved hyperlipidemia in golden hamsters, which correlated with an increase in SCFA levels and relative abundance of Parabacteroides, indicating its potential importance in functional foods that can help lower cholesterol.
研究领域:
微生物学
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营养学
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分子生物学
·
胃肠病学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL DAIRY JOURNAL
·
2026
·
IF 3.1
Ximeng Wang,Yanyan Li,Wenhao Zou,Yuanxuan Jiang,Yongqi Yang,Qin Wang,Zhangguo Ma,Rodrigo Ledesma-Amaro,Liping Wang
To improve the storage stability and antioxidant activity of yogurt, an exopolysaccharide (EPS)-producing strain, Lactobacillus fermentum SN4-1, was isolated from traditional Qinghai yak yogurt, and the EPS biosynthetic pathway was analyzed via whole-genome sequencing. A novel EPS (EPS-2) from SN4-1 was purified by anion-exchange chromatography and characterized by HPLC, HPGPC, and FT-IR. SN4-1 was combined with a commercial starter, and its effects on yogurt quality during cold storage were evaluated. Results showed that EPS-2 mainly consisted of mannose, glucose, and galactose (molar ratio 5.93:1.19:1) with an average molecular weight of 40.3 kDa. SN4-1 contained an EPS gene cluster ( eps-2 ) and multiple probiotic-related genes. During cold storage, the EPS content in yogurt with SN4-1 peaked at 144.21 mg kg -1 on day 5. Accordingly, the yogurt exhibited higher hardness, adhesiveness, cohesiveness, and viscosity, with adhesiveness increasing by 198.81%. Its water-holding capacity was 10.35% higher than that of the control on day 15. Moreover, the yogurt demonstrated strong radical scavenging capacities (DPPH 89.49%, ·OH 76.32%, O 2 - 63.23%, ABTS ∙+ 90.14%). These findings highlight the potential of SN4-1 in developing stable, clean-label probiotic yogurt.
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DOI
高影响因子
MEAT SCIENCE
·
2020
·
IF 3.644
Huiting Luo,Peijun Li,Hongwei Zhang,Xinping Diao,Baohua Kong
The objective of this study was to clarify whether formation of nitrosylmyoglobin (MbFe II NO) by Lactobacillus fermentum AS1.1880 in meat is due to nitric oxide synthase (NOS) activity. Confocal laser scanning microscopy exhibited strong green fluorescence in the L . fermentum sample treated with a nitric oxide (NO)-specific probe, directly indicating that NO was produced. Furthermore, determination of NOS activity based on the presence of NO metabolites indicated the existence of NOS in L.fermentum . A NOS inhibitor, N G -nitro-L-arginine methyl ester, significantly inhibited the activity of NOS in L.fermentum ( P < 0.05). Futhermore, NOS protein was detected in L.fermentum by Western blot analysis. L-arginine addition largely increased the NOS activity of L.fermentum ( P < 0.05). In meat batters , the redness of a sample inoculated with L.fermentum was higher than that of the control and colour was significantly improved with the addition of L-arginine ( P < 0.05), indicating that more MbFe II NO was formed.
研究领域:
食品科学
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微生物学
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生物化学
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产品关联
DOI
PubMed
高影响因子
Frontiers in Microbiology
·
2022
·
IF 6.064
Le Su,Feifan Ma,Zaiyong An,Xiuyu Ji,Ping Zhang,Qiulin Yue,Chen Zhao,Xin Sun,Kunlun Li,Baojun Li,Xinli Liu,Lin Zhao
Because of the increased incidence and prevalence, ulcerative colitis (UC) has become a global health issue in the world. Current therapies for UC are not totally effective which result in persistent and recurrent symptom of many patients. Lactobacillus with anti-inflammatory effects might be beneficial to the prevention or treatment for UC. Here, we examined the ameliorative effects of the metabolites of Lactobacillus fermentum F-B9-1 (MLF) in Caco-2 cells and dextran sodium sulfate (DSS)-induced UC model mice. MLF displayed intestinal barrier-protective activities in Caco-2 cells by increasing the expression of Occludin and ZO-1. They also showed anti-inflammatory potential in interleukin (IL)-1β and IL-6. In order to further examine the in vivo anti-inflammatory effect of MLF, the MLF was gavaged in the DSS-induced UC model mice. The intragastric administration of MLF effectively alleviated colitis symptoms of weight loss, diarrhea, colon shortening, and histopathological scores, protected intestinal barrier function by increasing Occludin and ZO-1, and attenuated colonic and systemic inflammation by suppressing production of IL-1β and IL-6. Finally, the use of MLF remodeled the diversity of the gut microbiota and increased the number of beneficial microorganisms. Overall, the results demonstrated that MLF relieved DSS-induced UC in mice. And MLF might be an effective therapy method to UC in the clinic in the future.
研究领域:
胃肠病学
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微生物学
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免疫学
·
药理学
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DOI
PubMed
高影响因子
PROCESS BIOCHEMISTRY
·
2019
·
IF 2.883
Kun Wang,Meng-meng Niu,Yue Wu,Rui-fang Zhu,Jing Zhao,Bao-xin Lu,Guang-cai Niu
This study investigated the physicochemical characteristics and antioxidant activities of cell-bound exopolysaccharides (c-EPS) from Lactobacillus fermentum S1 extracted using either phenol (CFP) or ethylenediaminetetraacetic acid (CFE). The extraction products, CFP and CFE, were homogeneous polysaccharides with molecular weights of 2.89 × 10 5 and 2.44 × 10 5 Da, respectively. Both CFP and CFE were composed of five kinds of monosaccharides. They had a main chain of β-D-Glc p -(1→2), α-L-Rha p -(1→2), β-D-Gal p -(1→3), α-D-Glc p- (1→3), α-D-Gal p -(1→3) and β-L-Rha p- (1→3,4) residues, and a tail of α-D-Man p -(1→) residue, but with different molar ratios. Trace amounts of D-Gal p- (1→) and L-Ara f -(1→2,5) residues were randomly distributed in the sugar chains. Although both CFP and CFE were in triple-helical conformation, they differed from each other in relation to surface morphology and thermal properties. The two c-EPS had different performances in radical scavenging and ferric reducing antioxidant power assays in vitro . The antioxidant capacity of both c-EPS extracts was confirmed in vivo using Caenorhabditis elegans , whose total antioxidant capacity and total superoxide dismutase activity increased after c-EPS treatment. Overall, the extraction method significantly affected the structure and biological activity of c-EPS. Moreover, the potent antioxidant activities of CFP and CFE support their use as natural antioxidants in dietary supplements or food additives.
研究领域:
微生物学
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食品科学
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生物化学
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产品关联
DOI
高影响因子
Food & Function
·
2020
·Vol. 11
·期 4
·3235-3244
·
IF 4.171
Yujin Liu,Minhao Xie,Peng Wan,Guijie Chen,Chunxu Chen,Dan Chen,Shijie Yu,Xiaoxiong Zeng,Yi Sun
Dicaffeoylquinic acids (DiCQAs), the main components of kudingcha made from the leaves of Ilex kudingcha, could be transformed by gut microbiota. However, the information about the related microorganisms and enzymes involved in the biotransformation of DiCQAs in the human gut is limited. Therefore, a strain of bacteria that could hydrolyze DiCQAs, belonging to Lactobacillus fermentum named L. fermentum LF-12, was isolated from human feces in the present study. Furthermore, an esterase for the hydrolysis of DiCQAs was purified from L. fermentum LF-12 and heterogeneously expressed in Escherichia coli. The esterase could be induced to exert superior hydrolytic activity in the presence of lactose as the carbon source. The molecular weight of the purified esterase was determined to be 31.9 kDa, and the isoelectric point, optimal pH and temperature for the esterase were 4.71, 6.5 and 45 °C, respectively. The enzyme activity was improved by Mg2+ and Ca2+, and reduced by Co2+, Cu2+, EDTA and some kinds of organic solvents. The present results provide new insights into the metabolism of DiCQAs by the human gut.
研究领域:
食品科学
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微生物学
·
生物化学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Chenglong Lv,Xiangfei Li,Jie Liu,Jiayan Gu,Fei Gao,Jing Sun,Xinyi Pang,Yingjian Lu
In this study, we aimed to develop microcapsules using sodium caseinate (NaCas)-oligosaccharides (OS) Maillard reaction conjugates (MRCs) to enhance the stability of Lactobacillus fermentum Q11 (LfQ11) in gastrointestinal fluids and food processing environments. Xylooligosaccharide (XOS), fructooligosaccharide (FOS), and inulin (INU) were conjugated with NaCas via the Maillard reaction to form MRCs for the microencapsulation of LfQ11. The characterization revealed that NaCas-XOS3h exhibited the highest grafting degree (24.97 %) and superior emulsifying activity, while NaCas-INU4h demonstrated enhanced prebiotic activity. Characterization of the microcapsules indicated that LfQ11@NaCas-XOS, LfQ11@NaCas-FOS, and LfQ11@NaCas-INU achieved high encapsulation efficiency (above 90 %) and were stabilized by hydrophobic interactions. Moreover, LfQ11@NaCas-XOS maintained higher viability than free LfQ11 after exposure to gastrointestinal fluids (82.46 %), heat stress at 70 °C (3.95 Log CFU/mL), and storage at 25 °C for 28 days (7.42 Log CFU/mL) than other microcapsules. All three MRCs-based microcapsules provided enhanced protection against ionic stress and acidic stress. Furthermore, all microcapsules exhibited low cytotoxicity and excellent biocompatibility. Notably, LfQ11@NaCas-XOS significantly reduced cholesterol levels in RAW264.7 foam cells more effectively than other treatments. These findings offer valuable insights into the application of different OS-protein conjugates as microencapsulated wall materials and the development of probiotic agents with cholesterol-lowering functions.
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Kun Wang,Mengmeng Niu,Di Yao,Jing Zhao,Yue Wu,Baoxin Lu,Xiqun Zheng
A cell-bound exopolysaccharide (c-EPS) from Lactobacillus fermentum S1 was isolated and purified to near homogeneity by anion exchange and gel filtration chromatography. The c-EPS is a homogeneous heteropolysaccharide with an average molecular weight of 7.19 × 10 5 Da and comprises mainly mannose, rhamnose, glucose, and galactose. Fourier transform infrared spectroscopy spectrum of the c-EPS exhibited typical characteristic absorption peaks of polysaccharides. Methylation and NMR analyses showed that the c-EPS had a backbone of α-D-Gal p -(1 → 3), α-L-Rha p -(1 → 2), α-D-Glc p -(1 → 3), β-D-Gal p -(1 → 3), β-D-Glcl p -(1 → 2), and β-L-Rha p -(1 → 3,4) residues, terminated with α-D-Man p -(1 → residue. The advanced structure study indicated the c-EPS not to have a triple-helical conformation, while the microstructural study revealed a hollow porous structure for c-EPS. Further, the thermal analysis showed that the degradation temperature for the c-EPS was 288.0 °C; its peak temperature was 89.4 °C with an enthalpy value of 273.1 J/g. Moreover, the c-EPS exhibited potent DPPH, hydroxyl, and ABTS + radicals scavenging activities, as well as FRAP in a dose-dependent manner, which could significantly enhance the T-AOC and SOD activity and reduce MDA level in Caenorhabditis elegans. Therefore, this c-EPS could be utilized as a promising natural antioxidant for application in functional foods.
研究领域:
食品科学
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生物化学
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微生物学
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产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2023
·
IF 8.8
Yueqin Li,Yunzhen Zhang,Lezhen Dong,Ying Li,Yahui Liu,Yang Liu,Lingyi Liu,Lianliang Liu
In this study, strains producing feruloyl esterase were screened by Oxford Cup clear zones method and by evaluating the ability to decompose hydroxycinnamoyl esters. The strain was identified by 16S rDNA molecular biology. The contents of dietary fiber, reducing sugar, water-extractable arabinoxylans, phytic acid, total phenolics, total flavonoid, phenolic compounds composition, microstructure and antioxidant activity in bran before and after fermentation were studied. Eight strains producing feruloyl esterase were screened, among which strain P 1 had the strongest ability to decompose hydroxycinnamoyl esters. The strain was identified and named L. fermentum NB02. Compared with unfermented bran, fermented bran exhibited higher contents of soluble dietary fiber, reducing sugar, water-extractable arabinoxylans, total phenolics, total flavonoid, and lower insoluble dietary fiber and phytic acid content. The dense surface structure of bran was destroyed, forming a porous structure. The release of phenolic compounds increased significantly. L. fermentum NB02 fermentation improved the antioxidant capacity of bran.
研究领域:
食品科学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）