INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Fei-Long Li,Qiang Zhou,Wei Wei,Jian Gao,Ye-Wang Zhang
Enzymatic NADP + regeneration is a promising approach to produce valuable chemicals under economic conditions. Among all the enzymatic routes, using water-forming NADH oxidase is an ideal one because there is no by-product. However, most NADH oxidases have a low specific activity to NADPH. In this work, a thermostable NADH oxidase from Lactobacillus rhamnosus (LrNox) was rationally engineered to switch its specificity from NADH to NADPH. The results show that mutants D177A, G178R, D177A/G178R, D177A/G178R/L179S improved the NADPH activity by a factor of 4–6. The highest NADPH catalytic efficiency ( K cat /K m 223.71 S −1 μm −1 , 47.6-fold higher than wild-type LrNox) and 51% of NADH activity retention were achieved by replacing the single amino acid Leu179 for serine (L179S) in LrNox. Modeling of L179S-NADPH complex reveals that the phosphate group of NADPH interacts with the hydroxyl of Ser179 with a strong hydrogen bond and several shorter hydrogen bonds with the amino group of Lys185 could stabilize the binding of NADPH in the L179S mutant. This work provides an efficient method for converting NAD(P)H specificity and shows that L179S mutant is a potential and efficient auxiliary enzyme for NADP + regeneration.
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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.
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高影响因子
CARBOHYDRATE POLYMERS
·
2019
·
IF 6.044
Wei Li,Liming Liu,Huafeng Tian,Xiaogang Luo,Shilin Liu
Probiotics are believed to provide benefits to human health; however, a good storage stability is the prerequisite for the probiotic products making function. Herein, we reported a pathway to fabricate the Ca-alginate/cryoprotectants/cellulose composite (ACFP) capsules to protect L. plantarum cells, which showed the minimal loss of viability during the vacuum freeze-drying process. The trehalose and whey protein isolate (WPI) ingredients in the cryoprotectants prolonged the dissolution time of Ca-alginate shell, which contributed to controlling the release of cells in the desired region. The dry ACFP capsules exhibited gradual release of L. plantarum cells in simulated intestinal fluid (SIF), 2.6 × 10 6 cfu/mL at 210 min. In addition, 0.1 g of the dry ACFP capsules showed the viable release amount of 3.3 × 10 6 cfu/mL after the storage of 160 days at 4 °C. The promising results provided a strategy of encapsulating probiotic cells to achieve long-term storage stability and enhanced controlled release behavior in simulated intestinal fluid in the meantime.
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高影响因子
Biology-Basel
·
2020
·Vol. 9
·期 7
·171
·
IF 3.796
Jianming Zhang,Yushan Bu,Chengcheng Zhang,Huaxi Yi,Daqun Liu,Jingkai Jiao
At present, De Man, Rogosa and Sharpe (MRS) broth is the medium of choice for promoting bacteriocin production. However, this medium is expensive and not applicable for large-scale production. Therefore, a low-cost and high-efficiency culture medium for bacteriocin Lac-B23 production byLactobacillus plantarumJ23 was developed. First, the effects of the composition of MRS broth on bacteriocin Lac-B23 production and bacterial growth were researched by a one variable at a time approach. Then, a Plackett-Burman design was used to screen significant components for production. Finally, the steepest ascent and central composite designs were used to obtain an optimum medium. The final composition of the modified MRS was much simpler than MRS broth, and the modified MRS contained only glucose, yeast extract, dipotassium phosphate, manganese sulfate monohydrate, Tween 80 and sodium acetate anhydrous. The highest bacteriocin Lac-B23 production reached 2560 activity units (AU)/mL in the modified MRS, which is nine times higher than that in MRS broth (280 AU/mL). Meanwhile, the cost per liter of the modified MRS (8.56 Ren Min Bi (RMB)/L) is 34.70% the cost of MRS broth (13.11 RMB/L), and the cost per arbitrary units of bacteriocin Lac-B23 in the modified MRS is approximately fourteen times more convenient (3.34 RMB/106AU) than in the MRS broth (46.82 RMB/106AU).Keywords:bacteriocin Lac-B23;low-cost;high-efficiency;culture medium
研究领域:
微生物学
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食品科学
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PubMed
高影响因子
Nanomaterials
·
2021
·Vol. 11
·期 3
·803
·
IF 5.076
Penghui Nie,Mengqi Wang,Yu Zhao,Shanji Liu,Ling Chen,Hengyi Xu
The potential toxicity of titanium dioxide nanoparticles (TiO2NPs) to mammals has become a widespread concern. Young individuals exposed to TiO2NPs have a higher risk than adults. In this study, the protective effects ofLactobacillus rhamnosusGG (LGG) on liver toxicity in young rats induced by TiO2NPs were explored. Results show that the four-week-old rats that underwent LGG after the oral intake of TiO2NPs could prevent weight loss, reduce hematological indicators (WBC and NEUT) and serum biochemical indicators (AST, ALT, AST/ALT, and ALP). Moreover, it alleviated the pathological damage of the liver (as indicated by the disordered hepatocytes, more eosinophilic, ballooning degeneration, and accompany with blood cells), but it did not reduce the Ti contents in the liver. In addition, RT-qPCR results indicated that LGG restored the expression of anti-oxidative stress-related genes, such asSOD1,SOD2,CAT,HO-1,GSH,GCLC, andGCLMin the liver. In summary, the hepatotoxicity of TiO2NPs in young rats is closely related to oxidative stress, and the antioxidant effect of LGG might protect the harmful effects caused by TiO2NPs.Keywords:titanium dioxide nanoparticles;Lactobacillus rhamnosusGG;liver;toxicity;oxidative stress
研究领域:
毒理学
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微生物学
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分子生物学
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PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2022
·
IF 8.025
Zhiwen Ge,Xuan Bao,Zhiyu Li,Xiaohong Chen,Wei Li,Xin Rui,Junjun Wu,Qiuqin Zhang,Mingsheng Dong
In order to study the mechanism of high viscosity of Sayram ketteki yoghurt, the growth, acidification properties, in situ exopolysaccharides (EPS) production of Lactobacillus helveticus MB2-1 in milk medium were investigated. The microstructure of the yoghurt was analyzed. The characteristics of in situ EPS produced by this strain in yoghurt were studied by high-performance liquid chromatography (HPLC), Fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV–vis) analysis. The amount of in situ EPS produced could be up to 689.47 mg/L. The micrographs of Sayram ketteki yoghurt demonstrated that the in situ EPS secreted by ropy L. helveticus MB2-1 were closely connected with proteins, effectively filling the three-dimensional network structure of casein clusters, thereby resulting in high viscosity of yoghurt. Besides, the molecular weight of in situ EPS was 9.34 × 10 4 Da, and the in situ EPS was determined to be a new heteropolysaccharide, containing fucose, which made it unique. Moreover, the set yoghurts added with in situ EPS were demonstrated fine effects on the texture improvement. These results illustrated that L. helveticus MB2-1 could be set as a good starter and the in situ EPS could be considered as a probiotic stabilizer substitute for fermented dairy products.
研究领域:
食品科学
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微生物学
·
乳品科学
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DOI
PubMed
高影响因子
Food Bioscience
·
2021
·
IF 4.24
Jiao Yuan,Yuvaraj Ravikumar,Guoyan Zhang,Junhua Yun,Yufei Zhang,Hossain M. Zabed,Xianghui Qi
l -arabinose isomerases (L-AIS) are enzymes that mediate the conversion of l -arabinose into l -ribulose and D-galactose into D-tagatose. The potential of L-AI from Lactobacillus parabuchneri CICC 6004 (LPAI) in D-galactose biotransformation using E. coli whole-cells was studied. The parameters investigated in this study were 1) the optimum pH, temperature, and cofactor specificity for maximum enzyme activity ; 2) the D-tagatose biosynthesis from D-galactose using whole-cells containing LPAI. The results showed that with D-galactose, the purified LPAI showed the highest activity, 15.52 U/mg at pH 6.7, 45 °C, and necessitates 3 mM Ca 2+ as its cofactor. The K m , V max and K cat /K m values of LPAI for D-galactose were 5.4 mM, 35.5 U/mg and 2.8 mM −1 min −1 , respectively, while the respective values for l -arabinose were found to be 4.3 mM, 63.1 U/mg and 5.9 mM −1 min −1 .The applicability of LPAI for D-tagatose synthesis was shown by using whole-cell biocatalyst approach. Under the optimum conditions, during one-stage biotransformation of D-galactose by E. coli whole cells, 39.0 g/L of D-tagatose was produced from 140 g/L of D-galactose after 50 h, which corresponded to the yield and productivity of 0.28 g/g and 0.78 g/L/h, respectively. Further addition of new cells into the reaction mixture in the second stage produced 54.0 g/L of D-tagatose after 100 h. The D-tagatose total yield and productivity were 0.39 g/g and 0.54 g/L/h, respectively. The results attained in this study showed LPAI as a potential candidate for the industrial production of D-tagatose.
研究领域:
生物化学
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生物技术
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酶学
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微生物学
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DOI
高影响因子
Foods
·
2025
·Vol. 14
·期 15
·2733
·
IF 5.1
Di Yuan,Shan Zhang,Bin Hong,Shan Shan,Jingyi Zhang,Dixin Sha,Shiwei Gao,Qing Liu,Shuwen Lu,Chuanying Ren
Growing demand for plant-based nutraceuticals drives the need for innovative bioprocessing strategies. This study developed an integrated approach combining germination and Lactobacillus-mediated fermentation to produce a γ-aminobutyric acid (GABA)-enriched functional beverage from brown rice. Systematic screening identified an optimal rice cultivar for germination. Sequential enzymatic liquefaction and saccharification were optimized to generate a suitable hydrolysate. Screening of 13 probiotic strains revealed that a 10-strainLactobacillus–Bifidobacteriumconsortium maximized GABA synthesis (12.2 mg/100 g). Fermentation parameters were optimized to 0.25% monosodium glutamate, 4% inoculum, 10 μmol/L pyridoxine hydrochloride, 37 °C, and 24 h. The resulting beverage achieved significantly elevated GABA concentrations while exhibiting low fat (0.2 g/100 g), reduced caloric content (233.6 kJ/100 g), and high viable probiotic counts (2 × 108CFU/g). This strategy demonstrates significant potential for the scalable production of multifunctional, plant-based nutraceuticals with targeted bioactive components.
研究领域:
食品科学与技术
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生物加工工程
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功能性食品
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微生物发酵
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营养保健品
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DOI
PubMed
高影响因子
Probiotics and Antimicrobial Proteins
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2025
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IF 4.4
Niu Lingdi,Li Hai,Guo Junjie,Jia Zheng,Chang Qingru,Liu Ning,Zhang Shuhe,Ge Junwei
The gut microbiota plays a complex role in immune system maturation and function. The induction of memory in innate immune cells appears to be part of a co-adaptation between the host and microbiome. As important gut commensals, certain Lactobacillus have been shown to induce innate immune memory. However, the universality, phenotypic characteristics, mechanisms of Lactobacillus -induced innate immune memory, and its potential applications in vaccine immunology remain poorly understood. Here, we discovered that specific strains of the gut commensal Lactobacillus can induce innate immune memory, resulting in a more balanced trained immunity phenotype through SOCS activation. Upon secondary stimulation, macrophages exhibited increased expression of IL-6 , IL-1β , IL-10 , IL-12 , IFN-β , and TGF-β . Peptidoglycan and components in the secretome sensitive to pancreatic enzymes were identified as key elements in inducing trained immunity. Furthermore, mice that underwent training demonstrated rapid resistance to S. aureus infection. Additionally, Lactobacillus -induced trained immunity significantly enhanced the protective efficacy of vaccines against MRSA. Our findings demonstrate that certain Lactobacillus strains can activate non-classical trained immunity, offering potential for enhancing vaccine efficacy. Our study provides new insights into the role of some gut commensals in immune modulation and suggests a novel approach to vaccine enhancement through trained immunity induced by specific gut commensals.
研究领域:
免疫学
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微生物组研究
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疫苗学
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固有免疫
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分子生物学
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宿主-微生物相互作用
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高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Zhen Wang,Sijie Zhang,Huiping Wang,Jihong Huang,Luyang Wang
Hyaluronic acid (HA), as a multifunctional hydrophilic polysaccharide , is potentially beneficial in improving the thermal stability of fermented modified starches, but relevant insights at the molecular level are lacking. The aim of this study was to investigate the effect of different levels (0 %, 3 %, 6 %, 9 %, 12 % and 15 %) of HA on the structural, thermal and pasting properties of wheat starch co-fermented with Saccharomyces cerevisiae and Lactobacillus plantarum . We found that the addition of HA increased the median particle size of fermented starch granules from 16.387 to 17.070 μm. Meanwhile, the crystallinity of fermented starch was negatively correlated with the HA content, decreasing from 14.70 % to 12.80 % ( p < 0.05). Fourier transform infrared spectroscopy results confirmed that HA interacted with starch granules and water molecules mainly through hydrogen bonding. Thermal analyses showed that the thermal peak of the composite correlated with the HA concentration, reaching a maximum of 73.17 °C at 12 % HA. In addition, HA increases the pasting temperature, reduces the peak, breakdown and setback viscosities of starch. This study demonstrates the role of HA in improving the thermal stability of fermented starch, providing new insights for traditional fermented food research and the application of HA in food processing.
研究领域:
食品科学
·
分子生物学
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DOI
PubMed
高影响因子
Food & Function
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2024
·
IF 5.1
Jiayi Zhang,Chengcheng Zhang,Leilei Yu,Fengwei Tian,Wei Chen,Qixiao Zhai
Gastrointestinal inflammation and intestinal barrier function have important effects on human health. Alcohol, an important foodborne hazard factor, damages intestinal barrier, increasing risk of disease. Lactobacillus reuteri strains have been reported to reduce gastrointestinal inflammation and strengthen the intestinal barrier. In this study, we selected three ant-inflammation L. reuteri strains to evaluate their role in the protection of the intestinal barrier and their immunomodulatory activity in a mouse model of gradient alcohol intake. Among the three strains tested (FSCDJY33M3, FGSZY33L6, and FCQHCL8L6), L. reuteri FSCDJY33M3 was found to protect the intestinal barrier most effectively, possibly due to its reduction on the expression of interleukin (IL)-1β, IL-6, and tumor necrosis factor-alpha (TNF-α) and increase on the expression of tight junction proteins (occludin, claudin-3). Genomic analysis suggested that the protective effects of L. reuteri FSCDJY33M3 may be related to functional genes and glycoside hydrolases associated with energy production and conversion; amino acid transport and metabolism; carbohydrate transport and metabolism; and DNA replication, recombination, and repair. These genes include COG2856, COG1804, COG2071, and COG1061, which encode adenine deaminase; acyl-CoA transferases; glutamine amidotransferase; RNA helicase; and glycoside hydrolases, including GH13_20, GH53, and GH70. Our results identified functional genes that may related to protection of alcohol-induced intestinal barrier damage, which might be useful for screening lactic acid strains that can protect the intestinal barrier.
研究领域:
微生物学
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免疫学
·
胃肠病学
·
基因组学
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PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Yan Hu,Shengpeng Zhu,Xuexin Ye,Zhijie Wen,Hudie Fu,Jiasi Zhao,Mohan Zhao,Xinxi Li,Yuqing Wang,Xiaojun Li,Li Kang,Ainiwaer Aikemu,Xinzhou Yang
Probiotics regulate intestinal flora balance and enhance the intestinal barrier, which is useful in preventing and treating colitis. However, they have strict storage requirements. In addition, they degrade in a strongly acidic environment, resulting in a significant decrease in their activity when used as microbial agents. Lactobacillus rhamnosus GG (LGG) was loaded into acid-resistant and colon-targeting double-layer microgels. The inner layer consists of guar gum (GG) and low methoxyl pectin (LMP), which can achieve retention and degradation in the colon. To achieve colon localization, the outer layer was composed of chitosan (CS) and sodium alginate (SA). The formulation demonstrated favorable bio-responses across various pH conditions in vitro and sustained release of LGG in the colon lesions. Bare LGG survival decreased by 52.2 % in simulated gastric juice (pH 1.2) for 2 h, whereas that of encapsulated LGG decreased by 18.5 %. In the DSS-induced inflammatory model, LGG-loaded microgel significantly alleviated UC symptoms in mice and reduced inflammatory factor levels in the colon. Encapsulation of LGG improved its stability in acidic conditions, thus increasing its content at the colon lesions and reducing pathogenic bacteria. These findings provide an experimental basis and a technical reference for developing and applying probiotic microgel preparations.
研究领域:
药理学
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微生物学
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胃肠病学
·
药物递送系统
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）