Molecular Catalysis
·
2023
·
IF 4.6
Nan Jiang,Xiaotong Du,Liangyu Zheng
In this study, a series of chiral lactams were successfully prepared by one-pot two-step reactions. It included a transamination reaction catalyzed by a ω -transaminase from Bacillus megaterium ( ω -TA Bm ), and subsequent spontaneous cyclisation. The different amine donors were firstly screened with ethyl levulinate as an amine acceptor, and both the excellent conversion and enantiomeric excess ( e.e. p ) of >99% could be achieved with 4-bromophenylethylamine as an amine donor, however, the long reaction time of 24 h was unfavorable for its application. After the amino acid residue Thr120 situated in the small pocket was mutated to Ser, the T120S variant could exhibit 10.6-fold higher activity comparing to that of wild type, and achieve the reaction with both conversion and e.e. p of >99% within 3 h. The T120S variant could also be applied to prepare the other chiral γ- and δ-lactams with excellent conversion and e.e. p . Furthermore, the inclusion bodies of ω -TA Bm and its variants could be aggregated as “native-like structures” to continuously prepare the chiral lactam for 18 h. The aim of the study is to provide a simply and efficiently biocatalytic route for preparing chiral lactams.
研究领域:
生物化学
·
酶工程
·
有机合成
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DOI
高影响因子
CATALYSIS COMMUNICATIONS
·
2014
·
IF 3.32
Jian-yong Zheng,Yu-qiang Wang,Wei-feng Luo,Sha-sha Zhou,Qing Zhu,Xiang-xian Ying,Zhao Wang
A new esterase-producing strain ( Bacillus amyloliquefaciens WZZ002) that exhibits high hydrolytic activity, excellent enantioselectivity, and high substrate tolerance on Boc- dl -Alanine methyl ester was isolated from soil samples. The reaction temperature, pH, and neutralizer optima of the cell-mediated biocatalysis were 35 °C, pH 8.0, and NH 3 ·H 2 O, respectively. The optimal substrate concentration was 2 M, with a biocatalyst loading of 50 g/L. Results showed that the enantiomeric excess values of substrate and product were both greater than 99%. Thus, bioprocessing with the use of the isolated strain is a promising route for the commercial production of Boc- d -Ala-OMe.
研究领域:
生物化学
·
微生物学
·
制药工程
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DOI
高影响因子
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2019
·Vol. 104
·期 2
·765-774
·
IF 3.67
Tang Dandan,Liu Wei,Huang Lei,Cheng Leming,Xu Zhinan
25-hydroxyvitamin D 3 has attracted considerable attention due to its great medical value and huge market demand in animal husbandry. Microbial production of 25-hydroxyvitamin D 3 has been recognized as an alternative superior to traditional chemical synthesis. In this study, a Gram-positive bacteria zju 4-2 (CCTCC M 2019385) was isolated from the soil using vitamin D 3 as the sole carbon source and was identified as Bacillus cereus according to its physiological characteristics and 16S rRNA analysis, which also showed a relatively high capacity for 25-hydroxyvitamin D 3 production. Through systematic optimization of different catalytic conditions, the optimal solvent system of vitamin D 3 , vitamin D 3 addition time and concentration, temperature, and pH were shown to be propylene glycol/ethanol (v/v = 9:1), early stationary phase, 2 g/L, 37 °C, and pH 7.2, respectively. With these optimal conditions, 796 mg/L of 25-hydroxyvitamin D 3 was achieved after 48 h bioconversion with zju 4-2 at the shake flask level. Finally, up to 830 mg/L 25-hydroxyvitamin D 3 with a yield of 41.5% was obtained in a 5 L fermentation tank. Our developed biotransformation process with this newly isolated strain provides a platform to produce 25-hydroxyvitamin D 3 efficiently at industrialization scale.
研究领域:
微生物学
·
生物技术
·
医药科学
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DOI
PubMed
高影响因子
Microorganisms
·
2025
·Vol. 13
·期 4
·798
·
IF 4.2
Xiaoyu Cao,Yu Zhang,Qianqian Xu,Hai Yan
Hyperuricemia is a metabolic disorder owing to the underexcretion and/or overproduction of uric acid (UA). Recent studies have shown that probiotics have many potential applications as functional foods to ameliorate hyperuricemia. In this study, we have successfully isolatedBacillus paranthracisYC03 with urate-lowering potential from Jiangshui. The in vitro results indicated that YC03 exhibited strong biodegradation capacities toward UA and its precursors (inosine and guanosine). Meanwhile, the cell-free extracts of YC03 were also found to catalyze and remove inosine and guanosine. To further explore the application potential of this strain in developing functional foods, we evaluated its probiotic properties through in vitro assays and whole genome analysis.B.paranthracisYC03 has excellent abilities, with tolerance to acid and bile salt and good adhesion. In addition, hemolytic assays, along with antibiotic resistance and biogenic amine production tests, have also preliminarily confirmed the safety of using YC03 in food. We have also annotated the key enzyme genes, includingauaG,hpt,rih,punAanddeoD, which are involved in the biodegradation of UA and nucleosides. The results of nucleoside biodegradation product detection will be valuable for exploring the metabolic pathway for biodegrading nucleosides with YC03. These findings provide meaningful insights for the development of functional foods to improve hyperuricemia usingB.paranthracisYC03.
研究领域:
微生物学
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营养学
·
医学
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DOI
PubMed
高影响因子
WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY
·
2025
·Vol. 41
·期 4
·1-15
·
IF 4.2
Zhao Jing-yi,Gao Fan,Wu Mengru,Li Yang,Chen Yong,Xiao Zijun
Enantiopure ( S )-2-methylbutanoic acid [( S )-2-MBA] is a high-value chiral compound with applications in fragrances, pharmaceuticals, and agrochemicals. However, conventional chemical synthesis lacks stereoselectivity, while existing biosynthetic methods suffer from low yield and purity. Here, we report a novel microbial process using Bacillus spizizenii ATCC 6633 for efficient ( S )-2-MBA production via L-isoleucine catabolism. Through targeted screening of rhizospheric soil isolates and Bacillaceae strains, ATCC 6633 demonstrated superior performance, producing 3.67 g/L ( S )-2-MBA with 99.32% enantiomeric excess ( ee ) under optimized conditions (45 °C, 8% inoculation, 5 g/L glucose, and 8 g/L L-isoleucine). A 58.92% conversion efficiency was achieved, and a simplified purification process recovered 63.90% product with 97.32% purity. Mechanistic studies suggested glucose depletion triggered ( S )-2-MBA accumulation, aligning with starvation-induced secondary metabolism. This cost-effective, eco-friendly approach eliminates racemic separation steps and harsh reagents, positioning ATCC 6633 as a promising biocatalyst for sustainable ( S )-2-MBA production.
研究领域:
生物化学
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微生物学
·
有机化学
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DOI
PubMed
高影响因子
BIOLOGICAL CONTROL
·
2023
·
IF 4.2
Chengxian Wang,Xingling Zhao,Kai Wu,Chengyue Liang,Jing Liu,Hong Yang,Changmei Wang,Bin Yang,Fang Yin,Wudi Zhang
Medicine plants such as Panax notoginseng (Sanqi) frequently experience replant failure owing to the accumulation of soilborne pathogens and autotoxins in continuous cropping soil. Bacillus sp. is a commonly used biocontrol agent to combat soilborne pathogens, but further research is needed to understand its impact on controlling Sanqi root rot and the underlying mechanisms. Here, we isolated and screened a Bacillus strain, B19, from Sanqi rhizosphere soil that exhibited potential for inhibiting Sanqi root rot pathogens. We then tested the strain's effect on the incidence of Sanqi root rot in continuous cropping soil, along with its motility/chemotaxis and biofilm formation ability (i.e., potential for root colonization). We also analyzed the strain's genomic characteristics, including potential secondary metabolite synthesis gene clusters. Our results showed that the strain B19 exhibited high inhibitory activity against fungal pathogens ( F. solani and F. oxysporum ) and could metabolize saponins as a sole carbon source. The application of B19 to continuous cropping soil significantly reduced the incidence of root rot in Sanqi seedlings. B19 was identified as B. velezensis through morphological characteristics, 16S rRNA and gyrA gene sequence analysis, and genome-level annotation. Notably, B19′s genome encodes many genes associated with functions such as motility/chemotaxis and biofilm formation, as well as 13 biosynthetic gene clusters that could encode secondary metabolites, including surfactin, fengycin, and siderophore. Additionally, B19 demonstrated the capability to produce volatile organic compounds that inhibit pathogenic fungi. The motility/chemotaxis and biofilm-forming ability of B19 were enhanced by saponins. Collectively, these properties could enhance B19′s biocontrol ability, thereby reducing the incidence of root rot.
研究领域:
植物病理学
·
微生物学
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DOI
高影响因子
Food Bioscience
·
2025
·
IF 5.9
Xiaoting Song,Changzheng Shi,Huan Chen,Fanqiang Meng,Zhaoxin Lu,Xiaomei Bie
Detection of foodborne pathogens is of great significance for ensuring food safety and human health. Therefore, we developed a new detection method, which combined strand exchange isothermal amplification (SEA) with lateral flow assay strip (LFS), for the rapid and simple detection of Bacillus cereus in food. SEA technique is an isothermal nucleic acid amplification method based on the respiration of DNA denatured bubble to achieve a dynamic dissociation state of DNA double strand. The reaction requires only a pair of primers and DNA polymerase. The primers involved in the reaction were modified with biotin and 6-carboxyfluorescein (6-FAM) respectively, which could combine the reaction system with lateral flow assay strip to achieve the result of visualization of reaction results. In this reaction system, the detection sensitivity of B . cereus pure bacterial solution could reach 7.5×10 2 CFU/mL, and the specificity of the reaction system was good. Without enrichment treatment, the detection sensitivity of artificially contaminated rice cake samples and milk samples could reach 8.3×10 3 CFU/mL and 8.3×10 2 CFU/mL, respectively. The results of test strip and amplification were identical, which proved that the system was suitable for the detection of real samples. In addition, the established detection system has great potential as a preliminary detection tool in resource-limited areas.
研究领域:
微生物学
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分子生物学
·
食品科学
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DOI
高影响因子
BIOPROCESS AND BIOSYSTEMS ENGINEERING
·
2020
·Vol. 44
·期 4
·727-735
·
IF 2.419
Wang Hongrao,Han Shuran,Wang Jiayi,Yu Shuyu,Li Xiaoyan,Lu Lei
Laccases are versatile oxidases that are capable of decolorizing various synthetic dyes. Recombinant Bacillus amyloliquefaciens laccase was immobilized as magnetic cross-linked enzyme aggregates (M-CLEAs) for application in dye decolorization. Several parameters influencing the activity recovery were evaluated during the synthesis of M-CLEAs. With ammonium sulfate as precipitant, maximum activity was recovered by cross-linking with 0.16% glutaraldehyde for 1 h. The prepared M-CLEAs exhibited improved activity under alkaline conditions. It remained 74% activity after incubation at 60 °C for 5 h. Enhanced tolerance towards NaCl was also observed for the M-CLEAs, with 68% activity remaining in the presence of 1 M NaCl. The immobilized laccase could rapidly decolorize more than 93% of reactive black 5 and indigo carmine in 1 h, while its catalytic efficiency towards reactive blue 19 was relatively low. After four cycles of consecutive reuse, the M-CLEAs could decolorize 92% of indigo carmine. The easy recovery and reusability of M-CLEAs facilitate the potential application of bacterial laccase in dye decolorization.
研究领域:
生物化学
·
环境科学
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产品关联
DOI
PubMed
高影响因子
Journal of Cleaner Production
·
2022
·
IF 11.072
Yuan Chen,Yuancai Chen,Boxi Wang,Chenchen Mao,Chao Liu,Rongrong Liu,Bing Yan
Microbial reduction is a sustainable approach for both environmental remediation and recycling of precious metals from waste. Bacteria-mediated reduction of palladium ions (Pd 2+ ) in wastewater under mild conditions is such a strategy. However, external electron donors are usually required for palladium bioreduction. Herein, a novel gram-positive bacterium, Bacillus thuringiensis Y9 ( B. thuringiensis Y9), was found to reduce Pd 2+ to palladium nanoparticles (Pd-NPs) with endogenous electron donors. Transcriptomic analyses revealed 443 and 439 differentially expressed genes response to palladium treatment under anaerobic and aerobic conditions , respectively. It was found the genes encoding NADH-quinone oxidoreductase, dehydrogenases , cytochrome c reductase, cytochrome c oxidase , quinone cycle and ribE in B. thuringiensis Y9 have strong positive relationship to palladium reduction. The removal efficiencies of palladium by B. thuringiensis Y9 are as high as 93 mg g −1 under anaerobic conditions and 60 mg g −1 under aerobic conditions. Hydrogenase also plays vital role in the bioreduction process. The maximum Pd removal ratio of 99.18% was obtained with the primary influencing factors using response surface methodology (RSM). Our study provides a novel and sustainable strategy for Pd recovery from wastewater. The transcriptome data are valuable for understanding the global bioreduction mechanism of the microbial conversion of palladium.
研究领域:
环境科学
·
微生物学
·
材料科学
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DOI
高影响因子
Nanomaterials
·
2024
·Vol. 14
·期 6
·512
·
IF 4.4
Yuan Chen,Jiaxing Wang,Daidi Chen,Boxi Wang,Jinchuan Wu,Rongrong Liu,Qingxin Li
Many studies have been conducted on the microbial reduction of Pd (II) to palladium nanoparticles (Pd-NPs) due to the environmental friendliness, low cost, and the decreased toxicity of Pd (II) ions. In this study, we investigate the reduction mechanism of Pd (II) byBacillus megateriumY-4 through proteomics. The data are available via ProteomeXchange with identifier PXD049711. Our results revealed thatB. megateriumY-4 may use the endogenous electron donor (NAD(P)H) generated by nirB, tdh, and fabG and reductase to reduce Pd (II) to Pd-NPs. The expression levels of fabG, tdh, gudB, and rocG that generate NAD(P)H were further increased, and the number of reduced Pd-NPs was further increased with the exogenous electron donor sodium formate. Endogenous electron mediators such as quinones and flavins inB. megateriumY-4 can further enhance Pd (II) reduction. The findings provided invaluable information regarding the reduction mechanism of Pd (II) byB. megateriumY-4 at the proteome level.
研究领域:
微生物学
·
环境科学
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产品关联
DOI
PubMed
高影响因子
Water
·
2024
·Vol. 16
·期 3
·416
·
IF 3
Qiang Li,Yuehui He,Boyan Wang,Nanhai Weng,Lei Zhang,Kaichun Wang,Fengrong Tian,Mingsheng Lyu,Shujun Wang
The biological denitrification of low-C/N wastewater is a great challenge in treatment plants due to the lack of microorganisms with heterotrophic nitrification–aerobic denitrification (HN-AD) abilities. In this study,Bacillussp. L2 was isolated from aeration tank water samples using a nitrification medium and screened for its ability to perform HN-AD in low-C/N wastewater. The strain showed a maximum NH4+-N removal rate of 98.37% under low-C/N conditions. In the presence of a mixed N source, strain L2 was capable of completely removing NH4+-N within 24 h. Furthermore, optimal nitrogen removal conditions for strain L2 were found to be C/N = 9, pH = 9, and sodium acetate as the C source. Under optimal conditions, the strain was able to maintain a high NH4+-N removal rate under 0–3% salinity and an NH4+-N concentration of 200 mg/L or less. The denitrification pathways of strain L2 were NH4+→NH2OH→NO2−(↔NO3−)→NO→N2O→N2and NH4+→NH2OH→NO→N2O→N2. Furthermore, semi-continuous wastewater treatment was conducted using immobilized technology, which resulted in more than 82% NH4+-N removal after three cycles of reuse. This study demonstrates the great potential ofBacillussp. L2 in wastewater treatment applications.
研究领域:
环境微生物学
·
污水处理
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DOI
高影响因子
INTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY
·
2025
·Vol. 78
·期 2
·e70015
·
IF 2.8
Yuxin Sun,Hongchao Dai,Wenwen Ge,Dan Xiong,Zhenquan Yang,Zhenbo Xu,Lei Yuan
Foodborne pathogen Bacillus cereus is widely distributed in dairy products and the processing environment. Beyond its threat to human health, the production of thermostable protease also poses a significant challenge to the dairy industry, particularly in pasteurised or ultra-high-temperature (UHT) processed milk products. Despite this, our understanding of dairy spoilage caused by B. cereus is very limited. This study aimed to evaluate the spoilage potential of a thermostable protease produced by B. cereus 12–1 in fluid milk. Specifically, crude protease characterisation, including optimum pH and temperature, the influence of Ca 2+ on enzyme activity and heat stability of protease, was studied. Moreover, the effects of this protease on the quality of both whole and skim UHT milk were evaluated, including zeta potential and particle size of milk, hydrolysis of milk protein, release of free amino acids and change of milk microstructure. This crude protease has relatively good stability at wide-ranging pH values from 5.0 to 10.0 (79.67–166.67 U/mL) and temperatures from 20°C to 70°C (92.67–165 U/mL), and maintained stability of 46.04% and 38.31% after heat treatment by 65°C/30 min or 100°C/10 min. Spoilage patterns in skim and whole UHT milk differ significantly due to variations in fat content. The protease caused protein hydrolysis in whole milk (15.25%) and skim milk (17.09%), effectively hydrolysed κ-casein and β-casein, caused the release of free amino acids (Lys, Val, Tyr, Phe, Ile, Met and Leu) in UHT milk and significantly increased particle size (increase by 940 nm for skim milk and 1319 nm for whole milk), and reduced zeta potential (reduction by 4 mV for skim milk and 3.83 mV for whole milk) of UHT milk. Results indicate the spoilage potential of crude protease from B. cereus and highlight the need to prevent dairy spoilage caused by B. cereus .
研究领域:
食品科学
·
微生物学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）