Complete genome sequence of the industrial strain Bacillus megaterium WSH-002

Bacillus megaterium, an industrial strain, has been widely used in protein production and the vitamin C industry. Here we reported a finished, annotated, and compared 4.14-Mbp high-quality genome sequence of B. megaterium WSH-002, which is the companion strain for Ketogulonicigenium vulgare in the vitamin C industry and is stocked in our laboratory.     

解淀粉芽孢杆菌相关功能机制研究进展

解淀粉芽孢杆菌(Bacillus amyloliquefaciens)属于芽孢杆菌属,可广泛应用于农业生产、食品工业、环境保护、化妆品行业、医药以及沙漠治理。这些应用与解淀粉芽孢杆菌的特性和相关功能紧密相连。正因为解淀粉芽孢杆菌有多方面的生理功能,如形成生物膜、定殖于植物、促进植物生长等,才使其应用的广泛性成为可能。对解淀粉芽孢杆菌相关重要生理特征和功能机制进行了总结归纳,旨在为更好开发和利用这种益生菌提供科学理论数据。     

Characterization of spore appendages from Bacillus cereus strains

AIMS: Further characterization and comparison of spore appendages from Bacillus cereus strains. METHODS AND RESULTS: Appendages were isolated from 10 B. cereus strains from the food industry and food-borne outbreaks. The appendage proteins were dissolved in sample buffer containing 2% SDS and 5% mercaptoethanol at 100 degrees C, and subjected to SDS-PAGE. None of the appendages showed identical protein patterns. Western blots, using antibodies raised against a 3.5 kDa appendage protein, showed that the majority of the appendage proteins reacted with the antibody. Removal of the appendages by sonic treatment of the spores did not alter their heat resistance. The appendages were digested by proteinase K, pepsin, and the enzymes in the detergent Paradigm 10, but not by trypsin or chymotrypsin. Spore adhesion to stainless steel was scarcely affected by removal of the appendages. Digestion of adhered intact spores (with appendages) with Paradigm 10 showed a high degree of variation. CONCLUSIONS: Spore appendages from B. cereus are complex proteinaceous structures that differ among strains. SIGNIFICANCE AND IMPACT OF THE STUDY: Information about spore appendages and their involvement in spore adhesion is crucial for improving cleaning methods used for control of bacterial spores in the food industry.     

Serine protease of Bacillus subtilis R]

Properties of a protease preparation obtained by ethanol precipitation of a concentrate of the culture fluid of Bacillus subtilis R (1 : 4 v/v; 4 degrees C) grown under the conditions of deep cultivation were studied. The use of specific inhibitors, EDTA and phenylmethylsulfonyl fluoride, made it possible to show that the enzyme belongs to the group of serine proteases. The preparation exhibited high stability in alkaline medium and thermostability; it hydrolyzed protein substrates and retained catalytic properties in the presence of a multicomponent detergent system. The preparation is recommended for use in those branches of industry where proteolysis is required and in the production of detergents (as a biological additive).     

芽胞杆菌生产嘌呤核苷研究进展

嘌呤核苷在食品和医药领域都有广泛的应用。应用芽胞杆菌生产嘌呤核苷类物质的研究始于 6 0年代 ,其后对合成途径及其代谢调控机制相继进行了深入的研究 ,以下就此做详尽的综述 ,并以肌苷、鸟苷为例 ,对利用芽胞杆菌发酵生产嘌呤核苷的菌种选育和工艺调控的进展做全面的回顾。     

Screening Bacillus subtilis for Effective L-theanine Production from Tea Plant Rhizosphere Soil

Applied Biochemistry and Microbiology - L-theanine is used as an additive in food industry due to its unique health benefits to human being. Using γ-glutamyltranspeptidase (GGT) for L-theanine...     

Starch industry wastewater-based stable Bacillus thuringiensis liquid formulations

Liquid formulations were developed from Bacillus thuringiensis (Bt)-fermented broths of starch industry wastewater (SIW) and of soya medium. Stability studies were carried out for 1 yr. Storage stability was tested by studying various physical and chemical (e.g., viscosity, particle size, corrosion, and suspendibility) and biological (e.g., microbial contamination, viable spores, and entomotoxicity) parameters at different pH levels and temperatures. Three suspending agents, sorbitol, sodium monophosphate, and sodium metabisulfite, were added to fermented broth in different concentrations. Sorbitol and sodium monophosphate in the ratio 3:1 was the best suspending agent combination for both formulations. Starch industry wastewater fermentation yielded cell and viable spore counts 10- and 4-fold greater than those from soya medium, respectively, and a 1.7-fold increase in entomotoxicity. However, both formulations started deteriorating at pH 6 and 6.5 and 40 and 50 degrees C. There were no signs of corrosion and microbial contamination in both types of formulations.     

Ultrafiltration recovery of entomotoxicity from supernatant of Bacillus thuringiensis fermented wastewater and wastewater sludge

The study investigates the recovery of active components (crystal proteins, spores and other factors of virulence) of Bacillus thuringiensis (Bt) based biopesticides from centrifuged supernatant, by ultrafiltration. The centrifuged fermented broths comprised, starch industry wastewater, non-hydrolyzed and hydrolyzed wastewater sludge and semi-synthetic soya medium (as control). The ultrafiltration membrane of 5 kDa gave highest recovery of the active components and increased the entomotoxicity in the retentates by 7.9%, 10.5%, 9.0%, 5.7%, for semi-synthetic soya medium, starch industry wastewater, non-hydrolyzed and hydrolyzed wastewater sludge, respectively. However, the retention of suspended solids on the membrane (measured via mass balance) varied with the type of fermented broths and was very high for hydrolyzed sludge (soya-15%; starch industry wastewater-12%; non-hydrolyzed sludge-7% and hydrolyzed sludge-68%). This reflected the deposit on the membrane. In the given context, scale-up of the ultrafiltration process will give better efficacy for non-hydrolyzed sludge and starch industry wastewater in comparison to soya and hydrolyzed sludge medium.     

Catalytic properties and potential applications of Bacillus lipases

Up to date more than 70 lipases from the Bacillus and Geobacillus genera have been isolated, but for most of them only basic biochemical properties have been reported. In general, Bacillus lipases are easily produced and display high tolerance toward organic solvents, proving them useful in the synthesis of esters for food industry, cosmetics and biodiesel production. Many lipases preserve their activity at extreme temperatures and pH, and in the presence of surfactants, hydrogen peroxide, sodium hypochlorite, and therefore they can be applied in laundry formulations. Bacillus lipases display diverse selectivity to the chain length of the acid, and few enzymes show positional specificity. Several enzymes can be applied in the production of enantiopure compounds for the pharmaceutical industry due to their remarkable enantioselectivity. The immobilization experiments with Bacillus lipases, though a limited number, illustrate the vast possibilities for optimization of the properties of the biocatalysts for a particular application. The paper summarizes available experimental data on Bacillus and Geobacillus lipases and identifies areas for further research.     

致病性大肠杆菌和蜡样芽胞杆菌的分离鉴定

【背景】猪只消化道疾病是养猪业上一大重要疾病,给养猪业带来一定的经济损失。大肠杆菌是引起猪腹泻的一种常见病原菌,可以引起不同日龄的猪腹泻,但主要以幼龄猪为主。【目的】旨在分离鉴定引起四川省眉山市一规模化养猪场病猪大规模腹泻的病原菌。【方法】采用常规细菌分离方法结合16S rRNA基因序列的分析方法从发病猪肝脏、胃以及污染的饲料分离鉴定细菌,并对分离株进行小鼠致病性试验、16S rRNA基因遗传进化树分析、毒力基因的检测、药物敏感试验。【结果】从腹泻猪肝脏中分离到一株致病性大肠杆菌,胃中分离到一株蜡样芽胞杆菌,并且追溯到传染源是该猪场饲料。通过检测这两株菌相应的毒力基因发现大肠杆菌不属于肠外致病性型,蜡样芽胞杆菌检测到了nheA、nheB、nheC、bceT、entFM 5种毒力基因;药敏试验表明常规的氨基糖苷类和头孢类抗生素对大肠杆菌抑菌效果较好,红霉素、氟苯尼考、头孢氨苄、头孢哌酮对蜡样芽胞杆菌抑菌效果较好,而蜡样芽胞杆菌对青霉素、阿莫西林等常规药物不敏感。【结论】饲料存在大肠杆菌和蜡样芽胞杆菌的混合污染。     

Optimization of spray drying process for Bacillus thuringiensis fermented wastewater and wastewater sludge

Response surface methodology was used to optimize spray drying process for producing biopesticide powders of Bacillus thuringiensis by using fermented broth of starch industry wastewater and wastewater sludge. Analysis of variance was carried out using number of viable spores in the powder as dependent variable. The determination coefficients of models were 92 and 94% for fermented broth of starch industry wastewater and wastewater sludge, respectively. Under the optimal conditions of the operational parameters of spray drying, the numbers of viable spores were 2.2 × 10⁸ and 1.3 × 10⁸ CFU/mg in the dry powders for starch industry wastewater and wastewater sludge respectively, with a loss of viable spores of 18 and 13% when compared with their respective fermented broths. The entomotoxicity (measured by the bioassay method) of the powders obtained under optimal conditions showed a loss of 28 and 18% when compared with the fermented broth of starch industry wastewater and wastewater sludge, respectively. The optimized results of spray drying were used for field application calculations. The volume of fermented broth required to produce powder formulated product when compared with the volume required for liquid formulation product in order to treat 1 ha of balsam fir was less and offered several advantages.     

枯草芽胞杆菌L-天冬氨酸a脱羧酶的酶学性质

b-丙氨酸是一种重要的医药化工原料,目前主要依靠化学法进行生产。探寻更为环保和高效的生物生产法是未来研究的一个方向。L-天冬氨酸a脱羧酶 (PanD) 能特异地脱去L-天冬氨酸的a羧基,生成b-丙氨酸。本文比较了3种分别来源于大肠杆菌、谷氨酸棒状杆菌及枯草芽胞杆菌的PanD比酶活 (分别为0.98、7.52和8.4 U/mg)。后两者的最适pH均为6.5,最适反应温度分别为65 ℃及60 ℃。与目前研究最多的来源于大肠杆菌和谷氨酸棒状杆菌的PanD相比,来源于枯草芽胞杆菌的PanD具有更好的活性和热稳定性,具有更强的工业应用潜力。同时,本文对该酶特有的翻译后自剪切及机理性失活现象进行了分析和讨论。     

A mutant Bacillus subtilis gamma-glutamyltranspeptidase specialized in hydrolysis activity

gamma-Glutamyltranspeptidase (GGT) catalyzes the hydrolysis of gamma-glutamyl compounds and the transfer of their gamma-glutamyl moieties to amino acids and peptides. The transpeptidation activity of Bacillus subtilis GGT is about 10-fold higher than its hydrolysis activity. In B. subtilis GGT, substitution of Asp-445 with Ala abolished its transpeptidation activity. The specific activity for hydrolysis of D445A GGT was 40.2% of that of the wild-type GGT. The K(m) value for L-glutamine was 15.3 mM. D445A GGT was salt tolerant like the wild-type GGT. These results indicate that D445A GGT will be highly useful as a 'glutaminase' in food industry.     

Complete genome sequence of Bacillus amyloliquefaciens XH7, which exhibits production of purine nucleosides

Here, we report the complete annotated genome sequence of Bacillus amyloliquefaciens XH7, which is used to produce purine nucleosides in industry. The genome sequence will allow for the characterization of the molecular mechanisms underlying its beneficial properties.     

Development of a Mutant Strain of Bacillus polymyxa Showing Enhanced Production of 2,3-Butanediol

2,3-Butanediol is a feedstock chemical of potential industrial importance. It can serve as a monomer for many polymers of consumer interest that are currently supplied by the fossil fuel industry. Bacillus polymyxa can grow on inexpensive waste products of the food-processing industry and produce this glycol. This paper describes a mutant strain of B. polymyxa which displays constitutive production of catabolic α-acetolactate synthase, an enzyme in the 2,3-butanediol pathway which is normally produced only in the late log or stationary phase of growth. The mutant was obtained by treating the wild type with nitrosoguanidine and subjecting it to a penicillin counterselection procedure. One of the selected mutant strains produced four times as much of the glycol as the wild type and utilized approximately 25% of the energy source, compared with essentially complete utilization of the energy source by the wild type. Studies are under way to optimize the production of the glycol by the mutant.     

巨大芽孢杆菌表达外源蛋白的特点及其研究进展

巨大芽孢杆菌是一种很有潜力的分泌型基因工程宿主菌,现已广泛应用于工业和学术研究领域。它具有表达率高、遗传稳定、产物可分泌、发酵工艺成熟等优点。本文综述了其自身的优点,表达载体的特点,巨大芽孢杆菌的转化方法,外源蛋白的表达,以及高效表达的策略,并对未来进行展望。     

Immobilization of an alkaline endopolygalacturonase purified from Bacillus paralicheniformis exhibits bioscouring of cotton fabrics

Bioprocess and Biosystems Engineering - Pectin degrading enzyme has been increasing interest in an industrial application as biocatalysts, such as juice, textile, and wine industry. Bacillus...     

Isolation and Molecular Characterisation of Alkaline Protease Producing Bacillus thuringiensis

Proteases are of particular interest because of their action on insoluble keratin substrates and generally on a broad range of protein substrates. Proteases are one of the most important groups of industrial enzymes used in detergent, protein, brewing, meat, photographic, leather, dairy, pharmaceutical and food industry. In the present study, the organism isolated from the protein rich soil sample was identified by biochemical and molecular characterisation as Bacillus thuringiensis and further optimum conditions for alkaline protease synthesis were determined. The growth conditions for B. thuringiensis was optimised by inoculating into yeast extract casein medium at different pH and incubating at different temperatures. The maximum protease production occurred at pH 8 and at 37 °C. B. thuringiensis showed proteolytic activity at various culture conditions. Optimum conditions for the protease activity were found to be 47 °C and pH 8. In the later stage, the blood removing action of crude and partially purified protease was found to be effective within 25 min in the presence of commercial detergents indicating the possible use of this enzyme in detergent industry. Enzyme also showed good activity against hair substrate keratin and can be used for dehairing.     

Bacillus amyloliquefaciens BLCC1-0238 Alone or in Combination with Mannan-Oligosaccharides Alleviates Subclinical Necrotic Enteritis in Broilers

Probiotics and Antimicrobial Proteins - Subclinical necrotic enteritis (SNE) is a severe intestinal disease in broilers which brings huge economic losses to poultry industry. Herein, the effects of...     

益生芽孢杆菌对动物免疫功能影响研究进展

益生芽孢杆菌是一种新型的微生态制剂,其抗性好,具有调节动物肠道微生态平衡、促进机体消化与吸收、增强动物免疫功能、提高动物生产性能等益生效应,在动物养殖业中得到了广泛的应用。本文主要综述了益生芽孢杆菌对动物免疫器官、特异性免疫、非特异性免疫和红细胞免疫等免疫功能的影响,免疫调节和产生抗菌物质两方面的作用机理,以及影响免疫效果的因素,提出有待研究的方向和解决的方法,为益生芽孢杆菌的应用提供理论参考。