BIORESOURCE TECHNOLOGY
·
2017
·
IF 5.651
Cai Hui,Xiaoxiao Guo,Pengfei Sun,Rashid Azim Khan,Qichun Zhang,Yongchao Liang,Yu-Hua Zhao
A newly verified adsorbent biofilm produced by Bacillus amyloliquefaciens DT was investigated for nitrite removal from aqueous solutions. The biofilm’s characteristics and adsorption mechanism were determined, with results indicating that nitrite ions were adsorbed onto the protonated amine sites of biofilm under acidic conditions. Analysis of various factors showed that higher nitrite adsorption capacities occurred at pH < 3.0 and higher temperatures as well as higher initial nitrite concentrations, with a maximum nitrite removal capacity of 116.84 mg/g. Furthermore, nitrite adsorption was well fitted to the pseudo second-order and Weber–Morris kinetic models, and the Freundlich and Sips isotherm models. Simultaneously, thermodynamic analysis demonstrated that nitrite adsorption is a spontaneous endothermic process. In summary, the adsorption of nitrite was complex, and mainly resulted from electrostatic attraction and intraparticle diffusion. Consequently, the B. amyloliquefaciens biofilm can be considered as a promising adsorbent for nitrite removal from wastewater.
研究领域:
环境科学
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微生物学
·
水处理
·
吸附技术
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DOI
高影响因子
BIOCHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 3.371
Zhengyu Tao,Gang Fu,Sijia Wang,Zhaoxia Jin,Jianping Wen,Dawei Zhang
The wider application of creatinase, an enzyme used to determine renal function, is limited by the yield problem and current production cannot meet the needs of society. Therefore, the work constructed an efficient B. subtilis expression strain for creatinase production based on cell leakage. Initial expression of creatinase in B. subtilis was achieved using the native promoter P hpa Ⅱ . Subsequently, the promoter was optimized, and the efficient expression of creatinase was realized by using the maltose-induced promoter P glv , which increased the enzyme activity 5-fold and the properties of creatinase were analyzed. Meanwhile, it was found that creatinase without a signal peptide could be secreted into the extracellular medium, so the secretion of creatinase in B. subtilis was investigated. Disabling the classical secretory pathways didn’t have an effect on the expression level of extracellular creatinase, indicating that the excretion of creatinase didn’t depend on these pathways. Calcein-AM/PI double staining results showed that the membrane of the expression strain was damaged, while electron microscopy images revealed that leakage sites were present on the surface of the expressing bacteria, which led to the passive leakage of creatinase from B. subtilis . Finally, the enzyme activity was further improved to 141.9 U/mL in 5-L high-density fermentation.
研究领域:
微生物学
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生物技术
·
酶学
·
发酵技术
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DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Zhenxiang Xu,Guoqiang Chen,Le Xue,Haibo Zhang,Jiming Wang,Haiying Xiang,Jinglong Li,Kai Zheng
Extraction polysaccharide from microorganism is a research hotspot. In this work, a new type of water-soluble exopolysaccharides (EPS) was isolated from Bacillus licheniformis . Firstly, response surface methodology (RSM), based on a three-level, three-factor, was used to determine optimum conditions for EPS extraction. And RSM analysis indicated optimum condition was at the temperature of 8 °C for 10.44 h with ethanol at a concentration of 79.22% (v/v), the maximum yield of EPS was 3.07 g/mL. Secondly, EPS were seperated using DEAE-Sepharose Fast Flow column chromatography and acquired two polysaccharide fractions, BL-P1 and BL-P2. BL-P1 had larger molecular weight than BL-P2 from structural analyses, because of higher content of mannose , ribose , glucuronic acid , galactose , arabinose and fructose in BL-P2. Moreover, the characterization of BL-P1 and BL-P2 was investigated with Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy, the results indicated that EPS was mainly composed of→3)-α- d -Gal p -(1→, →3,5)-α- l -Ara f -(1→, →3)-β- d -Glc p -(1→, β- d -Glc p -(1 → and→4)-β- l -Fuc p -(1 → 4)-β- d -Xyl p -(1 → 4)-α- l -Rha p (1 → 3) -β- d -Man p -(4 → residues. In vitro antioxidant activity assay, EPS exhibited potent quenching capacities on hydroxyl and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radicals in a dose-dependent manner. Furthermore, BL-P2 had higher activity than BL-P1 in inhibiting α-amylase and α-glucosidase, which would have potential to be applied in nutraceutical and pharmaceutical industries.
研究领域:
微生物学
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生物化学
·
药理学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF FLUORESCENCE
·
2015
·Vol. 26
·期 2
·451-457
·
IF 1.927
Liu Cui,Zhou Zhen,Zou Linling,Cao Yuan-Cheng,Liu Jun’An,Lin Yongjun
A highly sensitive transgenic protein analysis method was proposed here based on fluorescein diacetate (FDA). First, FDA was prepared by the ball mill to harvest the nano-sized organic particles. Further examines showed that the FDA size can be controlled by the speed of centrifugation which can obtain FDA in well-distributed size. Cy3 antibody immobilization tests showed that the proteins can attach onto the FDA particles while keep bioactivities. FDA and Cry1Ac antibody immunoassay tests showed that when the FDA particle was in 150 nm, the linear range was 0.01 ng/L-30 μg/mL. And it has the lower detection limitation of 0.01 ng/L, which is 100 times more sensitive than the ELISA methods. These results indicate that the FDA related immunoassays are the promising approach in the transgenic analysis.
研究领域:
生物化学
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分子生物学
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食品科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF BIOTECHNOLOGY
·
2021
·
IF 3.307
Bo Gao,Ning Zhao,Jieying Deng,Yang Gu,Shiru Jia,Ying Hou,Xueqin Lv,Long Liu
Methanol is a promising green feedstock for producing fuels and chemicals because it is inexpensive, clean, environmentally friendly, and easily prepared. Thus, many studies have been devoted to engineering non-native methylotrophic platform microorganisms to utilize methanol. This study adopted a series of strategies to develop a synthetic methylotrophic Bacillus subtilis that can use methanol as the carbon source, including the heterologous expression of methanol dehydrogenase (Mdh), enhancement of the expressions of 3-hexulose-6-phosphate synthase (Hps) and 6-phospho-3-hexuloisomerase (Phi), regulation of the expressions of key enzymes at both the translational and transcriptional levels, stabilization of the key enzyme expression through a dual-system for expressing the target genes on both the plasmid and genome, and improvement of the catalytic activity of Mdh with a recycling strategy for NAD + . As a result, the methanol consumption of the synthetic methylotrophic B. subtilis reached 4.09 g/L, with the maximum OD 600 showing a 2.21-fold increase compared with the wild-type B. subtilis , which cannot use methanol. We further deleted the phosphoglucose isomerase (Pgi) and added co-substrates to increase the supply of ribulose-5-phosphate (Ru-5-P), and the specific methanol consumption rate increased by an additional 27.54%. Finally, we successfully constructed two strains that cannot grow in M9 medium with xylose or ribose unless methanol is utilized. The strategies used in this study are generally applicable to other studies on synthetic methylotrophy .
研究领域:
微生物学
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代谢工程
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合成生物学
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产品关联
DOI
PubMed
高影响因子
Fermentation-Basel
·
2023
·Vol. 9
·期 9
·789
·
IF 3.7
William Rodrigues Alves,Thiago Alessandre da Silva,Arion Zandoná Filho,Luiz Pereira Ramos
This work aimed at producing lactic acid (LA) from sugarcane bagasse after steam explosion at 195 °C for 7.5 and 15 min. Enzymatic hydrolysis was carried out with Cellic CTec3 and Cellic HTec3 (Novozymes), whereas fermentation was performed withBacillus coagulansDSM2314. Water washing of pretreated solids before enzymatic hydrolysis improved both hydrolysis and fermentation yields. The presence of xylo-oligosaccharides (XOS) in substrate hydrolysates reduced hydrolysis efficiency, but their effect on fermentation was negligible. The presence of fermentation inhibitors in C5 streams was circumvented by adsorption on activated carbon powder with no detectable sugar losses. High carbohydrates-to-LA conversions (Yp/s) of 0.88 g·g−1were obtained from enzymatic hydrolysates of water-washed steam-exploded materials that were produced at 195 °C, in 7.5 min, and the use of centrifuged-but-never-washed pretreated solids decreased Yp/sby 16%. However, when the detoxified C5 stream was added at a 10% ratio, Yp/swas raised to 0.93 g·g−1for an LA productivity of 2.55 g·L−1·h−1. Doubling the pretreatment time caused a decrease in Yp/sto 0.78 g·g−1, but LA productivity was the highest (3.20 g·L−1·h−1). For pretreatment at 195 °C for 7.5 min, the elimination of water washing seemed feasible, but the use of longer pretreatment times made it mandatory to eliminate fermentation inhibitors.Keywords:sugarcane bagasse;steam explosion;enzymatic hydrolysis;fermentation;lactic acid
研究领域:
生物技术
·
化学工程
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DOI
高影响因子
Frontiers in Microbiology
·
2017
·
IF 4.076
Tahir Hafiz A. S.,Gu Qin,Wu Huijun,Raza Waseem,Hanif Alwina,Wu Liming,Colman Massawe V.,Gao Xuewen
Bacterial volatiles play a significant role in promoting plant growth by regulating the synthesis or metabolism of phytohormones. In vitro and growth chamber experiments were conducted to investigate the effect of volatile organic compounds (VOCs) produced by the plant growth promoting rhizobacterium Bacillus subtilis strain SYST2 on hormone regulation and growth promotion in tomato plants. We observed a significant increase in plant biomass under both experimental conditions; we observed an increase in photosynthesis and in the endogenous contents of gibberellin, auxin, and cytokinin, while a decrease in ethylene levels was noted. VOCs emitted by SYST2 were identified through gas chromatography-mass spectrometry analysis. Of 11 VOCs tested in glass jars containing plants in test tubes, only two, albuterol and 1,3-propanediole, were found to promote plant growth. Furthermore, tomato plants showed differential expression of genes involved in auxin (SlIAA1. SlIAA3), gibberellin (GA20ox-1), cytokinin (SlCKX1), expansin (Exp2, Exp9. Exp 18), and ethylene (ACO1) biosynthesis or metabolism in roots and leaves in response to B. subtilis SYST2 VOCs. Our findings suggest that SYST2-derived VOCs promote plant growth by triggering growth hormone activity, and provide new insights into the mechanism of plant growth promotion by bacterial VOCs.
研究领域:
微生物学
·
植物科学
·
分子生物学
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DOI
PubMed
高影响因子
Frontiers in Immunology
·
2024
·
IF 5.7
Zhuwei Liang,Chao Zhang,Xiaoyu Liu,Kaiyue Yang,Zhile Xiong,Bingshao Liang,Jialiang Mai,Xiaojun Xiao,Jie Liu,Pingchang Yang,Damo Xu,Zhenwen Zhou
Background: Milk allergy commonly occurs in children, mainly caused by bovine-derived casein (CAS) protein. Neutrophil-activating protein (NAP) of Helicobacter pylori plays an immunomodulatory role with potential to suppress Th2-type immune responses. Bacillus subtilis (B. subtilis) spores are commonly used as oral vectors for drug delivery.Objective: To investigate whether recombinantly expressed NAP on B. subtilis spores could be an effective treatment for CAS allergy in mouse.Methods: After CAS sensitization, mice were orally administered B. subtilis spores expressing recombinant NAP for 6 weeks. Allergic symptoms and parameters were evaluated after CAS challenge oral gavage, including allergic inflammation, splenic cytokines, and serum-specific antibodies. Protein levels of Toll-like receptor 2 (TLR2) and c-JUN in the jejunum tissue were measured by western blot. Bone marrow-derived macrophages (BMDMs) were stimulated with inactivated NAP spores to measure the influence on cytokine profiles in vitro.Results: NAP recombinant spore treatment significantly reduced allergic symptoms and intestinal inflammation. Interleukin-12 and interferon-gamma levels increased, whereas serum CAS-specific IgG1 and IgE levels decreased. TLR2 and c-JUN expression levels were elevated in the jejunal tissue. Inactivated NAP spores polarized BMDMs to the M1 phenotype and enhanced cytokine expression, which were inhibited by a TLR2 neutralizing antibody.Conclusion: NAP offers a new strategy in the treatment of CAS allergy by inhibiting the Th2 response, while eliciting macrophages to promote Th1 immune responses.
研究领域:
免疫学
·
过敏
·
微生物学
·
分子生物学
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产品关联
DOI
PubMed
高影响因子
iScience
·
2025
·
IF 4.1
Shuai Liu,Yi Li,Lin Quan,Hai-Xia Liu,Yang Luo,Yong-Zhong Wang
SUMMARY Optimizing cellulase biosynthesis in B. subtilis is crucial for enhancing enzymatic yield in lignocellulosic biomass conversion. However, the regulatory mechanisms linking intracellular NAD(H/ + ) levels to cellulase production remain elusive. In this study, we systematically screened thirteen genes associated with NAD + biosynthesis and NADH regeneration in B. subtilis Z2. Employing a modular engineering strategy with four distinct modules, we directed metabolic flux to enhance NAD + biosynthesis and NADH regeneration. Key genes ( ycel , nadV , nadM , mdh , and sucB ) were identified, and their co-expression in B. subtilis Z2 resulted in a 13.09-fold increase in intracellular NADH levels and a consequential 2.24- and 2.04-fold enhancement in the filter paper-hydrolyzing (FPase [representing total cellullase]) activity and carboxymethylcellulase (CMCase [representing endoglucanase]) activity, respectively. Experimental validations, including antagonist LaCl 3 treatment and spcF gene deletion, unequivocally established the calcium signaling pathway's role in regulating cellulase gene overexpression in response to elevated intracellular NAD(H/ + ) levels.
研究领域:
微生物学
·
生物化学
·
合成生物学
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产品关联
DOI
PubMed
高影响因子
PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY
·
2024
·
IF 4.2
Shan Ye,Siyu Zhou,Yihang Ma,Jiahao Yang,Xuqi Shi,Ruoyu Zhang,Zhuhong Yang,Deliang Peng,Zhong Ding
Root-knot nematodes ( Meloidogyne spp.) are highly destructive pests that cause significant yield losses annually. Biological control of nematodes has emerged as a potential alternative in sustainable agriculture. In this study, we originally isolated Bacillus cereus G5 from the rhizosphere soil of rice ( Oryza sativa ). Treatment with the fermentation supernatant of G5 in vitro demonstrated high toxicity to second-stage juveniles (J2) of Meloidogyne graminicola and remarkably inhibited egg hatching. Moreover, G5 steadily colonized rhizosphere soil and rice seedlings, and exhibited excellent biocontrol efficacy against M. graminicola under greenhouse conditions . Notably, the volatile organic compounds (VOCs) produced by G5 displayed high fumigant activity against M. graminicola. The G5 VOCs efficiently reduced the gall index and nematode population in rice roots, while also promoting rice growth in double-layered pot tests. Additionally, the expression of defense genes involved in the salicylic acid ( OsNPR1 , OsWRKY45, OsPAL1 ), jasmonic acid ( OsJaMYB , OsAOS2 ) and ethylene ( OsACS1 ) signalling pathways was significantly upregulated in rice seedlings treated with G5 VOCs. This suggests that G5 VOCs contribute to eliciting plant defense responses. Furthermore, we identified 14 major VOCs produced by G5 using solid-phase micro-extraction gas chromatography and mass spectrometry (SPEM–GC–MS). Notably, allomatrine, morantel, 1-octen-3-ol and 3-methyl-2-butanol displayed strong contact nematicidal activity. Among these, only 1-octen-3-ol demonstrated fumigant activity against J2s of M. graminicola, with an LC 50 value of 758.95 mg/L at 24 h. Overall, these results indicated that the B. cereus G5 and its synthetic VOCs possess high potential as biocontrol agents for managing root-knot nematodes .
研究领域:
植物病理学
·
农业科学
·
分子生物学
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF FOOD MICROBIOLOGY
·
2015
·
IF 3.082
Lei Rao,Zhenzhen Xu,Yongtao Wang,Feng Zhao,Xiaosong Hu,Xiaojun Liao
The objective of this study was to investigate the inactivation of the Bacillus subtilis spores by high pressure CO 2 combined with high temperature (HPCD + HT) and to analyze the clumping effect of the spores on their HPCD + HT resistance. The spores of B . subtilis were subjected to heat at 0.1 MPa and HPCD at 6.5–25 MPa, and 82 °C, 86 °C, and 91 °C for 0–120 min. The spores were effectively inactivated by HPCD + HT, but a protective effect on the spores was also found, which was closely correlated to the pressure, temperature and time. The spores treated by HPCD + HT at 6.5 and 10 MPa exhibited a two-stage inactivation curve of shoulder and log-linear regions whereas the spores at 15–25 MPa exhibited a three-stage inactivation curve of shoulder, log-linear and tailing regions, and these curves were well fitted to the Geeraerd model. Approximately 90% of pyridine-2,6-dicarboxylic acid (DPA) was released after HPCD + HT and the 90% DPA release time depend on the pressure and temperature. Moreover, the spore clumping in suspensions was examined by dynamic light scattering. The particle size of the spore suspensions increased with the increase of pressure, temperature and time, indicating the spore clumping. 0.1% Tween 80 as a surfactant inhibited the spore clumping and increased the inactivation ratio of the spores by HPCD + HT. These results indicated that the spore clumping enhanced the spores' resistance to HPCD + HT and induced a protective effect.
研究领域:
微生物学
·
食品科学
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产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2023
·Vol. 34
·期 11
·2309288
·
IF 19
Yi Liu,Mengyao Wu,Anqi Kang,Xiehaoran Zhang,Ronghui Xie,Yuanpei Huang,Jiaofang Huang,Lien-Yang Chou,Chao Zhong
Genetically modified microorganisms (GMMs) possess significant potential for a wide range of applications; however, their execution in real-world scenarios, particularly in environments characterized by scarce nutrients and unpredictable conditions, proves daunting. Drawing inspiration from the adaptability of natural seeds, living seed materials that combine a core–shell structure ZIF-8 and genetically engineered spores are introduced. By genetically modifying the Bacillus subtilis strain to express distinct fluorescent proteins, the visualization of spores within the hollow sphere is facilitated, allowing for differentiation between spore and bacteria states. Importantly, the ZIF-8 shell exhibits responsiveness to diverse nutrient levels, providing enhanced environmental resistance in comparison to bare spores upon exposure to hypochlorous acid, UV-C radiation, and even vacuum conditions. Moreover, the potential of living seed materials for living sensors of small molecules is showcased by elucidating that spores can be resuscitated into functional bacteria after release from ZIF-8 material. This research establishes a novel approach for the general fabrication of Metal-Organic Frameworks (MOF)-based living spore hybrid materials, offering environmentally controlled release of living materials across a multitude of applications.
研究领域:
生物技术
·
材料科学
·
微生物学
·
环境科学
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DOI
高影响因子
危险品化学品经营许可证（带存储）