INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2019
·
IF 4.784
Xiaoxiao Li,Yuxiang Bai,Hangyan Ji,Jinpeng Wang,Yinglu Cui,Zhengyu Jin
Pullulanase, a typical debranching enzyme, specifically hydrolyzes α-1,6 glycosidic linkages in pullulan, starch and so on. There is accumulated knowledge about the catalysis of pullulanase, but functional roles of acceptor subsites get less attention. According to the crystal structure of pullulanase from Bacillus subtilis str. 168, stacking interaction between tryptophan437 and glycosyl unit of α-CD was found. Trp437 located in conserved region III was highly conserved in pullulanases. But functional role of this residue remains unclear. Site-directed mutagenesis was used to determine the function of Trp437. Replacement of Trp437 with glycine, phenylalanine, proline, arginine resulted in mutants with undetectable hydrolysis activity and reverse hydrolysis activity. The secondary structure of mutated proteins showed no difference from the wild-type pullulanase, but they lost the capability to bind β-CD based on the ITC measurement. Molecular docking was performed to investigate the affinity of proteins to ligands including maltotriose, 6 2 -α-D-maltotriosyl-maltotriose and α-CD, showing the affinity of mutants to ligands became weaker compared to that of PulA. And the hydrogen bond between Trp437 and Glu525 in PulA only was found in mutant W437R. These results show that Trp437 at subsite +2 plays crucial role in catalysis of PulA, and it has little tolerance to change.
研究领域:
酶学
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微生物学
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结构生物学
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DOI
PubMed
高影响因子
GEOCHIMICA ET COSMOCHIMICA ACTA
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2015
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IF 4.331
Congcong Ding,Wencai Cheng,Yubing Sun,Xiangke Wang
This article has been retracted: please see Elsevier Policy on Article Withdrawal ( https://www.elsevier.com/about/our-business/policies/article-withdrawal ). This article has been retracted at the request of the Executive Editor-in-Chief. Concern was raised about the EDX spectra shown by the insets of Figure 1D and the top two XPS spectra of Figure 9A (Fe 0 pH 3.5 and Fe 0 + B. Subtilis pH 3.5), as well as the FTIR spectra from Figure S6 and the XPS spectra from Figure S7B-E, which contained features and noise that indicated data fabrication. The corresponding authors were not able to provide reasonable explanations for these features and the Editor decided to retract the article. Moreover, the top EDX spectrum shown by the insets of Figure 1D is highly similar to the spectrum shown by the inset of Figure 1C of the article that the authors have previously published in the Journal of Hazardous Materials 280 (2014) 399–408 http://dx.doi.org/10.1016/j.jhazmat.2014.08.023 . One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents an abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.
研究领域:
环境科学
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微生物学
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DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
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2022
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IF 6.449
Xutong Ma,Xinlu Liu,Yong Xu
The probiotic of Bacillus subtilis ( B.subtilis ) is widely used in animal husbandry as a promising alternative to antibiotics, and a high value-added bioproduct from abundant and low-cost agricultural straws. For efficient fermentation of xylose-rich corncob slurry to B. subtilis cells, the step-by-step fermentation process (SSFP) and one-step fermentation process (OSFP) were proposed and compared by the combined technology of sulfuric acid pretreatment and enzymatic hydrolysis with cellulase . Xylose and glucose were fermented separately and sequentially in the SSFP route, while they were co-fermented in OSFP route. Here, B. subtilis performed an efficient bioconversion and almost fermented simultaneously glucose, xylose and arabinose in corncob slurry. We could obtain 326.8 g of B. subtilis in SSFP and 323.7 g probiotic cells in OSFP from 1000 g of corncob, respectively. In general, the OSFP route was preferable by virtue of a straightforward process and simple operation.
研究领域:
微生物学
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生物工程
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产品关联
DOI
高影响因子
FOOD CHEMISTRY
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2023
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IF 8.8
Hao Luo,Yihong Bao,Ping Zhu
Nutritional and functional soy-based milk gains growing attention globally in food industry. However, its poor sensorial attributes, single flavor, and limited substance variety become critical issues in displaying balanced nutrition and multifunction for health. Herein, a novel probiotic lycopene-soy milk was developed by genome edited Bacillus subtilis harboring lycopene biosynthesis cassette with efficient lycopene production of 25.73 ± 1.57 mg/g DCW. Further investigation displayed desirable pH, reducing sugar, protein, total phenolic content and isoflavone for achieved milk than conventional soy milk , implying it with well-balanced nutritional quality . Notably, achieved milk exhibited stronger antioxidant capacity and higher isoflavone bioavailability for functionality. Moreover, it possessed significantly high scores for taste, appearance, and overall acceptability, suggesting its excellent sensorial attributes. To our delight, it is the first time to fortify soy-milk with probiotic and lycopene by genome edited B. subtilis to explore additive effect on improving nutritional value and functionality for food application.
研究领域:
食品科学
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微生物学
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营养学
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DOI
PubMed
高影响因子
Food Science & Nutrition
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2025
·Vol. 13
·期 1
·e4673
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IF 3.8
Junfei Xu,Aixiang Hou,Wenqi Li,Binbin Chen,Hong Wu,Huan Tan,Zhihong Xiao,Xianjin Wu,Juzuo Zhang
Traditionally fermented sufu is popular because of its flavor, abundance of nutrients, and long shelf life. However, traditional sufu is difficult to produce via industrial processes because of dominant microorganism attenuation during fermentation. Herein, specific protease-producing strains were isolated from traditional sufu. After strain identification, mutation, and domestication, the strains were applied in fermentation. The taste, texture, and nutrient and flavor components of the fermentation products were investigated via organoleptic, textural HPLC and HS-GC-IMS analyses. Results revealed that Bacillus subtilis (DF1) and the derived strains DF1v and DF1vd had increased protease activity relative to other strains. When these strains were applied for sufu fermentation, the production period significantly shortened to 6–8 days for pehtzes and to 20–26 days for postripening. The nutrient and flavor compound composition of both sufu pehtzes and products improved, including increases in water-soluble proteins, amino acids, and substances with beany and umami aromas and decreases in nonbeneficial biogenic amines and moldy odor-imparting substances. Among the strains, DF1vd showed the greatest benefits in sufu-assisted fermentation. In summary, a modified Bacillus subtilis strain (DF1vd) producing protease was isolated, which improved the nutrient profile and flavor of sufu and shortened the production period.
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
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
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2024
·Vol. 108
·期 1
·1-12
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IF 3.9
Chen Qianlin,Wang Bin,Pan Li
Abstract In this study, we successfully applied the strategy of combining tandem promoters and tandem signal peptides with overexpressing signal peptidase to efficiently express and produce γ-glutamyl peptidase (GGT) enzymes (BsGGT, BaGGT, and BlGGT) from Bacillus subtilis , Bacillus amyloliquefaciens , and Bacillus licheniformis in Bacillus subtilis ATCC6051Δ5. In order to avoid the problem of instability caused by duplicated strong promoters, we assembled tandem promoters of different homologous genes from different species. To achieve resistance marker-free enzyme in the food industry, we first removed the replication origin and corresponding resistance marker of Escherichia coli from the expression vector. The plasmid was then transformed into the B. subtilis host, and the Kan resistance gene in the expression plasmid was directly edited and silenced using the CRISPR/Cas9n-AID base editing system. As a result, a recombinant protein expression carrier without resistance markers was constructed, and the enzyme activity of the BlGGT strain during shake flask fermentation can reach 53.65 U/mL. The recombinant BlGGT was immobilized with epoxy resin and maintained 82.8% enzyme activity after repeated use for 10 times and 87.36% enzyme activity after storage at 4 °C for 2 months. The immobilized BlGGT enzyme was used for the continuous synthesis of theanine with a conversion rate of 65.38%. These results indicated that our approach was a promising solution for improving enzyme production efficiency and achieving safe production of enzyme preparations in the food industry. Key points
• Efficient expression of recombinant proteins by a combination of dual promoter and dual signal peptide.
• Construction of small vectors without resistance markers in B. subtilis using CRISPR/Cas9n-AID editing system.
• The process of immobilizing BlGGT with epoxy resin was optimized.
研究领域:
微生物学
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食品科学
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分子生物学
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DOI
PubMed
高影响因子
Bioresources and Bioprocessing
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2022
·Vol. 9
·期 1
·1-12
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IF 4.983
Ye Jing,Li Yunjie,Bai Yuqing,Zhang Ting,Jiang Wei,Shi Ting,Wu Zijian,Zhang Yi-Heng P. Job
To mimic the Escherichia coli T7 protein expression system, we developed a facile T7 promoter-based protein expression system in an industrial microorganism Bacillus subtilis. This system has two parts: a new B. subtilis strain SCK22 and a plasmid pHT7. To construct strain SCK22, the T7 RNA polymerase gene was inserted into the chromosome, and several genes, such as two major protease genes, a spore generation-related gene, and a fermentation foam generation-related gene, were knocked out to facilitate good expression in high-density cell fermentation. The gene of a target protein can be subcloned into plasmid pHT7, where the gene of the target protein was under tight control of the T7 promoter with a ribosome binding site (RBS) sequence of B. subtilis (i.e., AAGGAGG). A few recombinant proteins (i.e., green fluorescent protein, α-glucan phosphorylase, inositol monophosphatase, phosphoglucomutase, and 4-α-glucanotransferase) were expressed with approximately 25–40% expression levels relative to the cellular total proteins estimated by SDS-PAGE by using B. subtilis SCK22/pHT7-derived plasmid. A fed-batch high-cell density fermentation was conducted in a 5-L fermenter, producing up to 4.78 g/L inositol monophosphatase. This expression system has a few advantageous features, such as, wide applicability for recombinant proteins, high protein expression level, easy genetic operation, high transformation efficiency, good genetic stability, and suitability for high-cell density fermentation.
研究领域:
微生物学
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生物技术
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分子生物学
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基因工程
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DOI
PubMed
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
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2026
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IF 6.4
Qiangbo Zhao,Ruhan Xia,Pengxiang Han,Jiangyuan Han,Weihua Zhao,Xiangyan Zhou,Fuqiang Xu,Wenzhi Yao,Jianhe Wei,Miaoyin Dong,Mengfei Li
Astragalus mongholicus is a well-known traditional Chinese herbal medicine with a long history of medicinal use, while root rot caused by Fusarium oxysporum is a highly destructive soil-borne diseases that leads to yield and quality reduction. Although previous studies have demonstrated that the biocontrol strategy based on microbial agents could effectively inhibit root rot in crops, the biocontrol efficiency and potential mechanism in A. mongholicus have been rarely investigated. In this study, a novel strain GNRP-01A was isolated from the rhizosphere of wild A. mongolicus and exhibited significant biocontrol efficacy (77.8 %) against A. mongolicus root rot, which was identified as Bacillus subtilis based on morphology, 16S rRNA, and whole-genome sequence analyses. The B. subtilis GNRP-01A genome contained multiple biosynthetic gene clusters encoding secondary metabolites ( e.g., surfactin, subtilosin A, bacillibactin) and the genes that promote plant growth ( e.g., amylase, protease, cellulase). Additionally, GC-MS analysis identified 13 volatile organic compounds (VOCs), among which 2-dodecanone, 2-tridecanone, and 6-methyl-2-heptanone showed strong antifungal activities with inhibition rates of 81.53 %, 89.17 %, and 91.86 %, respectively. Moreover, the expression levels of genes associated with plant induced systemic resistance (ISR , e.g. , AmCHI2 , AmPAD4 , AmPDF2.2 and AmPR-10 ) were significantly up-regulated in F. oxysporum + GNRP-01A treated plants, indicating the activation of ISR of A. mongolicus . Collectively, B. subtilis GNRP-01 A controls A. mongholicus root rot through synergistic strategy involving the production of antifungal metabolites and VOCs, activation of plant ISR. These results provide new insights into the biocontrol mechanism of B. subtilis against A. mongholicus root rot, as well as support the potential applications of B. subtilis GNRP-01A as an effective biocontrol agent for root rot prevention and management in medicinal plants.
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产品关联
DOI
高影响因子
Processes
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2020
·Vol. 8
·期 3
·259
·
IF 2.753
Jing Zhang,Muhammad Bilal,Shuai Liu,Jiaheng Zhang,Hedong Lu,Hongzhen Luo,Chuping Luo,Hao Shi,Hafiz M. N. Iqbal,Yuping Zhao
Herein, a bactericide-secretingBacillusstrain, potentially useful as a biocontrol agent, was isolated from the commercial Yanjing Natto food. Following the biochemical and physiological evaluation, the molecular identification was performed using 16S rDNA sequencing of polymerase chain reaction-amplified DNA that confirmed the natto isolate asBacillus subtilisnatto (B. subtilisnatto). The biocontrol (microbial inhibitory) capability ofB. subtilisnatto was investigated againstStaphylococcus aureus,Escherichia coli,Salmonella typhimurium, and yeast (Yarrowia lipolytica) and recorded. The antimicrobial activity ofB. subtilisnatto was further enhanced by optimizing the growth medium for optimal bactericides secretion. Under optimized conditions,B. subtilisnatto exhibited much higher inhibitory activity againstS. aureuswith a zone of inhibition diameter up to 27 mm. After 48 h incubation, the optimally yieldedB. subtilisnatto broth was used to extract and purify the responsible bactericides by silica gel column chromatography, gel column chromatography, and semi-preparative high-performance liquid chromatography. Structural identification of purified bactericides (designated as NT-5, NT-6, and NT-7) fromB. subtilisnatto was performed by13C-nuclear magnetic resonance (NMR) and mass spectral analyses. The NMR comparison also revealed that NT-5, NT-6, and NT-7 had identical structures, except for the fatty chain. In summary, the present study suggests the improved biocontrol and/or microbial inhibitory potential of newly isolated bactericides secretingB. subtilisnatto.Keywords:biocontrol agent;Bacillus subtilisnatto;isolation;molecular identification;medium optimization;antimicrobial activity;bactericides;spectral analyses
研究领域:
微生物学
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生物技术
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药学
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产品关联
DOI
高影响因子
Catalysts
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2019
·Vol. 9
·期 9
·734
·
IF 3.444
Jian Zhang,Yan Shao,Weiwei Wang
Curcumin is a naturally occurring polyphenolic compound that is commonly used in both medicine and food additives, but its low aqueous solubility and poor bioavailability hinder further clinical applications. For assessing the effect of the glycosylation of curcumin on its aqueous solubility, two glycosyltransferase genes (BsGT1andBsGT2) were cloned from the genome of the strainBacillus subtilisATCC 6633 and over-expressed inEscherichia coli.Then, the two glycosyltransferases were purified, and their glycosylation capacity toward curcumin and its two analogues was verified. The results showed that bothBsGT1andBsGT2could convert curcumin and its two analogues into their glucosidic derivatives. Then, the structures of the derivatives were characterized as curcumin 4′-O-β-D-glucoside and two new curcumin analogue monoglucosides namely, curcumoid-O-α-D-glucoside (2a) and 3-pentadienone-O-α-D-glucoside (3a) by nuclear magnetic resonance (NMR) spectroscopy. Subsequently, the dissolvability of curcumin 4′-O-β-D-glucoside was measured to be 18.78 mg/L, while its aglycone could not be determined. Furthermore, the optimal catalyzing conditions and kinetic parameters ofBsGT1andBsGT2toward curcumin were determined, which showed that the Kcat value ofBsGT1was about 2.6-fold higher than that ofBsGT2, indicating that curcumin is more favored forBsGT2. Our findings effectively apply the enzymatic approach to obtain glucoside derivatives with enhanced solubility.Keywords:curcumin 4′-O-β-D-glucoside;glycosyltransferases;Bacillus subtilisATCC 6633
研究领域:
生物化学
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酶学
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药理学
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产品关联
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2015
·
IF 2.912
Xiongliang Huang,Zhe Li,Chenyu Du,Jufang Wang,Shuang Li
A xylanase gene was cloned and characterized from Thermoanerobacterium aotearoense SCUT27, which was attested to consist of a signal peptide, one glycoside hydrolase family 10 domain, four carbohydrate binding modules, and three surface layer homology domains. The change of expression host from Escherichia coli to Bacillus subtilis resulted in a 4.1-fold increase of specific activity for the truncated XynAΔSLH. Five different versions of secretion signals in B. subtilis indicated that it was preferably routed via a Sec-dependent pathway. Purified XynAΔSLH showed a high activity of 379.8 U/mg on beechwood xylan. XynAΔSLH was optimally active at 80 °C, pH 6.5. Thin layer chromatography results showed that xylobiose and the presumed methylglucuronoxylotriose (MeGlcAXyl3) were the main products liberated from beechwood xylan catalyzed by the recombinant xylanase. All of the results suggest that XynAΔSLH is a suitable candidate for generating xylooligosaccharides from cellulosic materials for industrial uses.
研究领域:
生物技术
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酶学
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微生物学
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产品关联
DOI
PubMed
高影响因子
Polymers
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2022
·Vol. 14
·期 17
·3523
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IF 4.967
Fengqin Wang,Man Du,Lixia Kai,Shuai Du,Weilian Hu,Yizhen Wang,Yuanzhi Cheng
To provide a safe and effective supplement of the essential trace element selenium, we focused on the biosynthesis of nanoselenium (SeNPs) via probiotics. A novel kind of exopolymer-functionalized nanoselenium (SeEPS), whose average size was 67.0 ± 0.6 nm, was produced byBacillus subtilisSR41, whereas the control consisted of exopolymers without selenium (EPS). Chemical composition analysis, Fourier transform infrared (FTIR) spectroscopy and high-performance liquid chromatography (HPLC) confirmed that SeEPS and EPS shared similar polysaccharide characteristic groups, such as COO- and C=O, and contained not only 45.2–45.4% of sugars but also 23.5–24.7% of proteins and some lipids. Both SeEPS and EPS were primarily composed of mannose, amino glucose, ribose, glucose and galactose. Furthermore, to identify the biologically active component of SeEPS, three kinds of selenium particles with different stabilizers [Se(0), bovine serum albumin-Se and EPS-Se] were synthesized chemically, and their ability to scavenge free radicals in vitro was compared with that of SeEPS and EPS. The results revealed that EPS itself exhibited weak superoxide and hydroxyl radical scavenging abilities. Nevertheless, SeEPS had superior antioxidant properties compared to all other products, possibly due to the specific structure of SeNPs and exopolymers. Our results suggested that exopolymer-functionalized SeNPs with specific monosaccharide composition and structure could eventually find a potential application as an antioxidant.Keywords:exopolymer-functionalized nanoselenium;monosaccharide composition analysis;free radical scavenging ability
研究领域:
生物技术
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生物化学
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材料科学
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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）