Metabolites
·
2023
·Vol. 13
·期 7
·785
·
IF 4.1
Peizhou Yang,Wenjing Wu,Danfeng Zhang,Lili Cao,Jieshun Cheng
Aflatoxin pollution poses great harm to human and animal health and causes huge economic losses. The biological detoxification method that utilizes microorganisms and their secreted enzymes to degrade aflatoxin has the advantages of strong specificity, high efficiency, and no pollution inflicted onto the environment. In this study,Bacillus subtilisWJ6 with a high efficiency in aflatoxin B1degradation was screened and identified through molecular identification, physiological, and biochemical methods. The fermentation broth, cell-free supernatant, and cell suspension degraded 81.57%, 73.27%, and 8.39% of AFB1, respectively. The comparative transcriptomics analysis indicated that AFB1led to 60 up-regulated genes and 31 down-regulated genes inB. subtilisWJ6. A gene ontology (GO) analysis showed that the function classifications of cell aggregation, the organizational aspect, and the structural molecule activity were all of large proportions among the up-regulated genes. The down-regulated gene expression was mainly related to the multi-organism process function under the fermentation condition. Therefore,B. subtilisWJ6 degraded AFB1through secreted extracellular enzymes with the up-regulated genes of structural molecule activity and down-regulated genes of multi-organism process function.Keywords:aflatoxin B1;Bacillus subtilis;microbial degradation;comparative transcriptomics;biological detoxification
研究领域:
微生物学
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毒理学
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分子生物学
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环境科学
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DOI
PubMed
高影响因子
Frontiers in Bioengineering and Biotechnology
·
2021
·
IF 5.89
Yang Bin,Sun Yiwen,Fu Shouying,Xia Miaomiao,Su Yuan,Liu Chuan,Zhang Chunzhi,Zhang Dawei
Ribulose 5-phosphate (Ru5P) and guanosine 5′-triphosphate (GTP) are two key precursors of riboflavin, whereby Ru5P is also a precursor of GTP. Ribulose 5-phosphate 3-epimerase (Rpe) catalyzes the conversion of ribulose 5-phosphate into xylulose 5-phosphate. Inactivation of Rpe can reduce the consumption of Ru5P, enhancing the carbon flux toward riboflavin biosynthesis. Here we investigated the effect of mutation of rpe and other related genes on riboflavin production, physiological and metabolic phenotypes in Bacillus subtilis LY (BSLY). Introducing single nucleotide deletion (generated BSR) or nonsense mutation (generated BSRN) on the genomic copy of rpe, resulting in more than fivefold increase of riboflavin production over the parental strain. BSR process 62% Rpe activity, while BSRN lost the entire Rpe activity and had a growth defect compared with the parent strain. BSR and BSRN exhibited increases of the inosine and guanine titers, in addition, BSRN exhibited an increase of inosine 5′-monophosphate titer in fermentation. The transcription levels of most oxidative pentose phosphate pathway and purine synthesis genes were unchanged in BSR, except for the levels of zwf and ndk, which were higher than in BSLY. The production of riboflavin was increased to 479.90 ± 33.21 mg/L when ribA was overexpressed in BSR. The overexpression of zwf, gntZ, prs, and purF also enhanced the riboflavin production. Finally, overexpression of the rib operon by the pMX45 plasmid and mutant gnd by pHP03 plasmid in BSR led to a 3.05-fold increase of the riboflavin production (977.29 ± 63.44 mg/L), showing the potential for further engineering of this strain.
研究领域:
微生物学
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生物技术
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代谢工程
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生物化学
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DOI
PubMed
高影响因子
BIOCHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 4.446
He Li,Dongbang Yao,Jingru Ying,Xudong Han,Xuecheng Zhang,Xiuju Fang,Zemin Fang,Yazhong Xiao
A strategy that combines signal peptide (SP) optimization and translation efficiency improvement was used to enhance the extracellular production of raw starch-degrading α-amylase AmyZ1 from Pontibacillus sp. ZY in Bacillus subtilis . The optimal SP YpuA screened from 173 B. subtilis SPs mediated a 1.28-fold higher AmyZ1 activity than the original SP amyQ . Then, strategies of translation efficiency improvement, including optimizing the Shine-Dalgarno-like (SD-like) sequence, constructing a dual 5′-untranslated region (dual-UTR), optimizing the spacer region of the UTR, and optimizing the 5′-proximal coding sequence, were used to enhance AmyZ1 production. The resulting recombinant strain (BZYACO6) containing SD-like3, dUTR2, and an optimized 5′-proximal coding sequence (O6) produced the highest extracellular α-amylase activity of 2974.0 U/mL in shake flask, 2.07-fold higher than that of the original strain BZd34 (1437.6 U/mL). After fermentation optimization, the BZYACO6 strain produced an extracellular AmyZ1 activity of 3915.2 U/mL in shake flask and 25,070 U/mL in 3-L fermenter, representing the highest level of recombinant raw starch-degrading α-amylase production reported to date. Furthermore, this work provides a strategic reference for enhancing the extracellular production of other recombinant proteins in B. subtilis .
研究领域:
微生物学
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生物技术
·
酶学
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DOI
高影响因子
Frontiers in Microbiology
·
2016
·
IF 4.165
Rao Lei,Wang Yongtao,Chen Fang,Liao Xiaojun
The inactivation effects of high pressure CO2 + nisin (simultaneous treatment of HPCD and nisin, HPCD + nisin), HPCD→nisin (HPCD was followed by nisin), and nisin→HPCD (nisin was followed by HPCD) treatments on Bacillus subtilis spores in aqueous solutions were compared. The spores were treated by HPCD at 6.5 or 20 MPa, 84–86°C and 0–30 min, and the concentration of nisin was 0.02%. Treated spores were examined for the viability, the permeability of inner membrane (IM) using flow cytometry method and pyridine-2, 6-dicarboxylic acid (DPA) release, and structural damage by transmission electron microscopy. A synergistic effect of HPCD + nisin treatment on inactivation of the spores was found, and the inactivation efficiency of the spores was HPCD + nisin > HPCD→nisin or nisin→HPCD. Moreover, HPCD + nisin caused higher IM permeability and DPA release of the spores than HPCD. A possible action mode of nisin-enhanced inactivation of the spores was suggested as that HPCD firstly damaged the coat and cortex of spores, and nisin penetrated into and acted on the IM of spores, which increased the damage to the IM of spores, and resulted in higher inactivation of the spores.
研究领域:
食品科学
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微生物学
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DOI
PubMed
高影响因子
Environmental Science-Processes & Impacts
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2026
·
IF 3.9
Sadiq Naveed,Xinwei Zhou,Dongqiang Zhu
Extracellular reductive dechlorination of chlorinated aliphatic hydrocarbons (CAHs) by non-electroactive bacteria is rarely investigated. In this study, we demonstrated that common bacteria Gram-positive Bacillus subtilis (B. subtilis) and Gram-negative Escherichia coli (E. coli) in aqueous suspensions (1.2 × 108 cells per mL) could dechlorinate a model CAH compound hexachloroethane (HCE, initial 40 µmol L−1) at ratios of 83.7% and 54.1% respectively to pentachloroethane (PCE) and tetrachloroethylene (TCE) after 56 h incubation at pH 7.0 and 30 °C. The majority of the parent compound (HCE) and reaction products (PCE and TCE) present in the extracellular matrix indicated the predominance of extracellular reduction. Removing EPS from bacteria suppressed HCE reduction, while adding extra dissolved EPS slightly enhanced HCE reduction. The enhanced reduction of HCE by low-molecular-weight EPS (<3 kDa) relative to bulk EPS of B. subtilis and its counterpart high-molecular-weight EPS (>3 kDa) indicated that low-molecular-weight EPS were more enriched in active reducing agents. Additionally, dechlorination of HCE by electrochemically reduced glutathione and disodium anthraquinone-2,6-disulfonate or juglone suggested that thiol groups and quinones were involved as reducing agents and electron mediators, respectively. These findings underscore a previously unknown process of extracellular reductive dechlorination of CAHs by common non-electroactive bacteria and the key role played by EPS.
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产品关联
DOI
PubMed
高影响因子
Food Bioscience
·
2026
·
IF 6.2
Zhaoyuan Liu,Hang Jia,Baoxiang Pan,Bin Wang,Li Pan
Phospholipase A 2 (PLA 2 ) is an important biocatalyst with broad applications in food processing, oil refining, and biotechnology. However, PLA 2 enzymes from natural sources often exhibit insufficient activity and poor thermal stability, which limits their industrial use. This study aims to enhance PLA 2 thermal stability and catalytic activity by combining deep-learning-guided site screening with combinatorial assembly, with the goal of producing catalysts better suited for efficient industrial applications. We applied a deep learning-guided design strategy, specifically utilizing the MutCompute model, to identify mutation hotspots in PLA 2 . Guided by these predictions, we generated single-point and combinatorial mutants and obtained variants with markedly improved properties. The N21E/I84L/Q116M triple mutant showed a 225% increase in specific activity relative to the wild type (WT), enhanced thermal stability (the half-life at 50 °C increased from 26.69 min to 33.85 min), and a broadened active pH range (WT retained high activity only between pH 7.0 and 7.5, N21E/I84L/Q116M retained ≥71.5% of its maximal activity over pH 6.0–9.0). To further facilitate industrial production, we optimized the expression of this superior mutant in Bacillus subtilis . The optimized promoter P 43 -P aprE increased expression by 69.6%, and the optimal signal peptide SP pelB enhanced secretion by 18.4%. Finally, a whole-cell biocatalyst was developed by surface-displaying the engineered PLA 2 . In the biotransformation of soybean lecithin, this mutant whole-cell biocatalyst yielded 48.8% more product than its WT counterpart. In conclusion, this study presents a comprehensive and efficient molecular engineering strategy for PLA 2 , providing a highly active, stable, and easily expressed biocatalyst well-suited for industrial application.
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DOI
高影响因子
Biocatalysis and Agricultural Biotechnology
·
2025
·
IF 3.8
Lingyun Yao,Qingru Huang,Huatian Wang,Tao Feng,Chuang Yu,Kun Xie,Hao Liu,Shiqing Song,Li Shao,Min Sun
The Camellia seed cake (CSC) is by-product of tea tree ( Camellia oleifera ) oil that rich in proteins and traditionally discarded or used as fertilizers, which would lead to a serious waste of the high-quality resources. In this work, Bacillus subtilis was employed to the submerged fermentation of CSC for production of potential bioactive peptides. After optimization by single-factor experiments and response surface methodology (RSM), the optimal fermentation conditions revealed to be material-to-liquid ratio of 30 g/L, inoculum volume of 19.0 %, and temperature of 35.4 °C, and the peptide production yield reached 11.68 % after RSM optimization. The amino acid composition analysis of CSC hydrolysates (CSCH) showed that CSCH was mainly composed of Tyr, Cys, Gly and Val, and 94.01 % of the peptides contained in the CSCH had a molecular weight of less than 3 kDa. In addition, the CSCH revealed strong antioxidant and tyrosinase inhibition potential in vitro, and the Lineweaver–Burk analysis indicated that CSCH exhibited a reversible competitive inhibition against the tyrosinase. Peptides were supposed to be major components that contribute to the bioactivity of CSCH due to their high contained concentration. The results demonstrated that CSCH could be developed as a new type of pure natural antioxidant and anti-tyrosinase agents used for health-promoting products, and these findings would provide useful information for better transformation and utilization of the CSC by-products.
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
高影响因子
JOURNAL OF FOOD SCIENCE
·
2025
·Vol. 90
·期 8
·e70466
·
IF 3.4
Li Ran,Yongjun Wu,Jing Jin,Lincheng Zhang,Cen Li,Shuoqiu Tong,Feng Wen,ZhongHui Mou
The globalization of food culture has driven the growth of the flavor market, with Bacillus subtilis- fermented soybean products widely used as traditional Asian condiments due to their distinctive soy sauce-like aroma. However, the molecular mechanism underlying aroma formation remains incompletely understood. Building on previous systematic multi-omics studies, this study identifies a key role for l -threonine catabolism in regulating pyrazine biosynthesis. Using homologous recombination, we performed targeted knockouts of the tdh and kbl genes to generate single mutants (BJ3-2Δ tdh and BJ3-2Δ kbl ) and a double mutant (BJ3-2Δ tdh - kbl ). Headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS), along with sensory evaluation, revealed that the tdh knockout drastically reduced 2,5-dimethylpyrazine (2,5-DMP) levels by 96.79%. The double knockout achieved a 97.73% reduction and completely eliminated 3-ethyl-2,5-dimethylpyrazine (EDMP). Interestingly, the kbl knockout alone enhanced 2,5-DMP production by 65.34%, and the odor activity value of EDMP increased to 10.50. Exogenous supplementation experiments confirmed that 2,5-DMP is a critical contributor to nutty, sweet, and buttery aromas, while also intensifying smoky undertones. Overall, this study elucidates the regulatory function of l -threonine catabolism in pyrazine biosynthesis, linking microbial metabolism to food flavor and offering a metabolic engineering strategy for targeted aroma modulation in fermented foods. Practical Applications This research provides valuable insights into the mechanism underlying the formation of soy sauce-like aroma, laying the foundation for optimizing 2,5-dimethylpyrazine (2,5-DMP) concentrations to fine-tune aroma profiles. These findings may support the environmentally friendly production of high-quality soy sauce-like aroma foods, potentially reducing reliance on artificial additives.
研究领域:
食品科学
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微生物代谢
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风味化学
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发酵技术
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分子生物学
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产品关联
DOI
PubMed
高影响因子
BIOPROCESS AND BIOSYSTEMS ENGINEERING
·
2019
·Vol. 43
·期 1
·75-84
·
IF 2.371
Zhan Yijing,Zhu Ping,Liang Jinfeng,Xu Zheng,Feng Xiaohai,Liu Yi,Xu Hong,Li Sha
A safe, efficient, environmentally friendly process for producing isomaltulose is needed. Here, the biocatalyst, sucrose isomerase (SIase) from Erwinia rhapontici NX-5, displayed on the surface of Bacillus subtilis 168 spores (food-grade strain) was applied for isomaltulose production. The anchored SIase showed relatively high bioactivity, suggesting that the surface display system using CotX as the anchoring protein was successful. The stability of the anchored SIase was also significantly better. Thermal stability analysis showed that 80% of relative activity was retained after incubation at 40 °C and 45 °C for 60 min. To develop an economical industrial fermentation medium, untreated beet molasses (30 g/L) and cold-pressed soybean powder (50 g/L) were utilised as the main broth components for SIase pilot-scale production. Under the optimal conditions, the productive spores converted 92% of sucrose after 6 h and the conversion rate was 45% after six cycles. Isomaltulose production with this system using the agricultural residues, untreated beet molasses and soybean powder, as substrates is cost-effective and environmentally friendly and can help to overcome issues due to the genetic background.
研究领域:
生物技术
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生物化学工程
·
食品科学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
Frontiers in Nutrition
·
2026
·
IF 5.5
Jin-Rong Ma,Lu-Lu Liu,Jiang-Miao Zhang,Yuan-Liang Wang,Ai-Xiang Hou,Lin Hu,Ming-Zhi Zhu,Yu-Lian Chen,Yu Xiao,Wen-Ping Kong
Debaryomyces and Bacillus are dominant microbial groups in dark teas such as Fu brick tea and play a key role in the formation of their characteristic flavors. In this study, dark tea infusion was co-fermented using Debaryomyces hansenii and Bacillus subtilis isolated from Fu brick tea. A comprehensive analytical approach was employed, including headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS), high-performance liquid chromatography (HPLC), relative odor activity value (rOAV) analysis, molecular docking, and sensory evaluation, to systematically investigate changes in tea polyphenols, catechins profile, and volatile organic compounds (VOCs) during fermentation and to identify key aroma-active substances. The results demonstrated that co-fermentation significantly reduced the contents of total tea polyphenols (by 45.12%) and ester catechins (by 92.63%), while promoting the accumulation of gallic acid. Volatile component analysis revealed that the co-fermentation integrated the aromatic profiles of both monocultures, retaining key aroma compounds such as linalool and nonanal, and introducing unique constituents such as α-cadinol, collectively forming a complex aroma profile dominated by floral, fruity, and woody notes. Molecular docking analysis confirmed strong binding affinity between key floral aroma compounds (e.g., linalool) and the olfactory receptor OR1A1. Sensory evaluation indicated that the co-fermented tea infusion achieved the highest overall scores in aroma and taste, exhibiting a mellow and sweet aftertaste along with a pure, bright, and refreshing aroma, highlighting the synergistic effect of co-culture fermentation. This study reveals that co-fermentation with D. hansenii and B. subtilis can effectively improve the flavor quality of dark tea infusion through synergistic regulation of polyphenol transformation and volatile compounds formation, providing a controllable bioprocess for the development of flavor-oriented, quality-stable fermented tea beverages with potential for industrial scale-up and commercial application.
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DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2021
·
IF 8.198
Kemin Lv,Zhimeng Yu,Marcelo M. Pedroso,Bin Wu,Zhen Gao,Bingfang He,Gerhard Schenk
Establishing a suitable immobilization strategy to improve the accessibility of immobilized cellulase for insoluble cellulose and subsequently recover the enzyme from the remaining substrate is crucial to promote the industrialization of biofuels. Here, using iminodiacetic acid (IDA) and Ni2+ ions, a novel metal-chelated copolymer of methacrylic acid and methyl methacrylate was prepared for the immobilization of His-tagged processive endoglucanase EG5C-1 via affinity interaction between polyhistidine tag and Ni2+. The optimum loading capacity of the functionalized polymer (Eud-IDA-Ni2+) for EG5C-1 was about 280 mg/g, where more than 80% of the activity was recovered. Immobilized EG5C-1 exhibited improved thermal and pH stability and better reusability than the free one, and after five cycles of usage, the hydrolysis productivity remained above 70% of the initial value. The Eud-IDA-Ni2+/EG5C-1 biocomposite displayed reversibly soluble–insoluble characteristics with pH change, which was in the soluble state during the enzyme reaction process but could be recovered in an insoluble form by lowering the pH after the reaction. Thus, the yield obtained from the hydrolysis of an insoluble phosphoric acid-swollen cellulose substrate was similar for the free and immobilized form of EG5C-1. Our combined results suggested that a metal-ion-chelated, pH-responsive polymer had the potential for His-tagged cellulase immobilization to improve both the operational efficiency and economic benefit of the cellulosic biorefinery industry.
研究领域:
生物化学
·
生物工程
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2018
·
IF 3.909
Lu Zhao,Youzhi Zhou,Song Qin,Panpan Qin,Jianlin Chu,Bingfang He
β-Galactosidases can catalyze the hydrolysis of lactose and the synthesis of galacto-oligosaccharides (GOS) from lactose. The catalytic activity of β-galactosidases is usually inhibited by galactose and glucose, which hampers the complete hydrolysis of lactose in food products. In this report, a β-galactosidase (denoted as BMG) from Bacillus megaterium YZ08 without the inhibition by galactose and glucose is the first to our knowledge reported. Efficient secretory expression of BMG was successfully achieved in Bacillus subtilis WB800. With the increasing of galactose and glucose, the activity of BMG dramatically enhanced. With addition of 0.6 M galactose or 1 M glucose, the initial activity to o NPG hydrolysis was increased by 2.1-fold and 4.3-fold, respectively. Moreover, the synthetic rate of galacto-oligosaccharides was enhanced by 1.1-fold and 1.9-fold with the addition of 0.7 M galactose or glucose, respectively. The GOS (278 g/L) from 600 g/L lactose by BMG were efficiently produced within 12 h, and the substrate lactose was completely used up. These results suggest that BMG shows a potential application in the food industry.
研究领域:
生物化学
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生物技术
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食品科学
✓ 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）