High-salinity growth conditions promote tat-independent secretion of tat substrates in Bacillus subtilis

The Gram-positive bacterium Bacillus subtilis contains two Tat translocases, which can facilitate transport of folded proteins across the plasma membrane. Previous research has shown that Tat-dependent protein secretion in B. subtilis is a highly selective process and that heterologous proteins, such as the green fluorescent protein (GFP), are poor Tat substrates in this organism. Nevertheless, when expressed in Escherichia coli, both B. subtilis Tat translocases facilitated exclusively Tat-dependent export of folded GFP when the twin-arginine (RR) signal peptides of the E. coli AmiA, DmsA, or MdoD proteins were attached. Therefore, the present studies were aimed at determining whether the same RR signal peptide-GFP precursors would also be exported Tat dependently in B. subtilis. In addition, we investigated the secretion of GFP fused to the full-length YwbN protein, a strict Tat substrate in B. subtilis. Several investigated GFP fusion proteins were indeed secreted in B. subtilis, but this secretion was shown to be completely Tat independent. At high-salinity growth conditions, the Tat-independent secretion of GFP as directed by the RR signal peptides from the E. coli AmiA, DmsA, or MdoD proteins was significantly enhanced, and this effect was strongest in strains lacking the TatAy-TatCy translocase. This implies that high environmental salinity has a negative influence on the avoidance of Tat-independent secretion of AmiA-GFP, DmsA-GFP, and MdoD-GFP. We conclude that as-yet-unidentified control mechanisms reject the investigated GFP fusion proteins for translocation by the B. subtilis Tat machinery and, at the same time, set limits to their Tat-independent secretion, presumably via the Sec pathway

MTA セメントと納豆菌混和材料の齲蝕治療応用と相乗効果： 基礎的実験の意義と今後

Bacillus subtilis produces a number of useful substances and is nonpathogenic in humans; therefore, this bacterium is used in probiotic therapy. Indirect pulp capping with a mixture of B. subtilis spore powder and mineral trioxide aggregate (MTA) cement is effective for avoiding pulpectomy or tooth extraction (personal communication). Based on reports of the clinical utility of this mixture, we conducted a study to establish the scientific basic of this effect. A paper describing this work(Oka, 2018) included two major results: (1) B. subtilis can proliferate in an admixture with MTA cement, which has an extremely high pH, at which it was thought that neutral bacteria such as B. subtilis cannot survive; and (2) the admixture has synergistic effects with respect to antimicrobial activities. These results support the hypothesis that a combination of B. subtilis and MTA cement is likely to be clinically useful for treatment of dental caries. However, we did not fully describe the background and significance of the experiments in the previous paper(Oka, 2018). Here, we describe the details of the experiments, including presentation of unpublished data, and add a discussion of further development of this research

BacillOndex: An Integrated Data Resource for Systems and Synthetic Biology

BacillOndex is an extension of the Ondex data integration system, providing a semantically annotated, integrated knowledge base for the model Gram-positive bacterium Bacillus subtilis. This application allows a user to mine a variety of B. subtilis data sources, and analyse the resulting integrated dataset, which contains data about genes, gene products and their interactions. The data can be analysed either manually, by browsing using Ondex, or computationally via a Web services interface. We describe the process of creating a BacillOndex instance, and describe the use of the system for the analysis of single nucleotide polymorphisms in B. subtilis Marburg. The Marburg strain is the progenitor of the widely-used laboratory strain B. subtilis 168. We identified 27 SNPs with predictable phenotypic effects, including genetic traits for known phenotypes. We conclude that BacillOndex is a valuable tool for the systems-level investigation of, and hypothesis generation about, this important biotechnology workhorse. Such understanding contributes to our ability to construct synthetic genetic circuits in this organism

Uptake of branched-chain alpha-keto acids in \u3ci\u3eBacillus subtilis\u3c/i\u3e

Bacillus subtilis has a constitutive system for the uptake of alpha-keto-beta-methylvalerate, alpha-ketoisovalerate, and (probably) alpha-ketoisocaproate. A mutation, kauA1, which blocks the uptake of alpha-keto-beta-methylvalerate and alpha-ketoisovalerate, is located between metB and citK on the B. subtilis chromosome

The methionine salvage pathway in Bacillus subtilis

BACKGROUND: Polyamine synthesis produces methylthioadenosine, which has to be disposed of. The cell recycles it into methionine through methylthioribose (MTR). Very little was known about MTR recycling for methionine salvage in Bacillus subtilis. RESULTS: Using in silico genome analysis and transposon mutagenesis in B. subtilis we have experimentally uncovered the major steps of the dioxygen-dependent methionine salvage pathway, which, although similar to that found in Klebsiella pneumoniae, recruited for its implementation some entirely different proteins. The promoters of the genes have been identified by primer extension, and gene expression was analyzed by Northern blotting and lacZ reporter gene expression. Among the most remarkable discoveries in this pathway is the role of an analog of ribulose diphosphate carboxylase (Rubisco, the plant enzyme used in the Calvin cycle which recovers carbon dioxide from the atmosphere) as a major step in MTR recycling. CONCLUSIONS: A complete methionine salvage pathway exists in B. subtilis. This pathway is chemically similar to that in K. pneumoniae, but recruited different proteins to this purpose. In particular, a paralogue or Rubisco, MtnW, is used at one of the steps in the pathway. A major observation is that in the absence of MtnW, MTR becomes extremely toxic to the cell, opening an unexpected target for new antimicrobial drugs. In addition to methionine salvage, this pathway protects B. subtilis against dioxygen produced by its natural biotope, the surface of leaves (phylloplane)

Enzim Amilase Sebagai Komponen Antagonis Bacillus Subtilis B315 Terhadap Ralstonia Solanacearum Kentang

Enzyme amylase as an antagonist component of Bacillus subtilis B315 against potato Ralstonia solanacearum. One of the antagonist mechanism of Bacillus subtilis B315 is that it produced secundary metabolites. Enzyme amylase is produced by B. subtilis B315 as a secondary metabolite. The aims of the research were: (1) to test mechanism of antagonistics by B. subtilis B315 against potato Ralstonia solanacearum and (2) to detect antibiosis activity of B. subtilis B315. The research was conducted in the Laboratory of Plant Protection Agriculture Faculty and Laboratory of Integrated Research of Jenderal Soedirman University from April to October 2014. The research method is an experimental with growing double layer of B. subtilis B315 in YPGA medium and Ralstonia solanacearum in water agar. This research used a Completely Randomized Design with 3 treatments and 8 replications. The treatments were B. subtilis B1, B. subtilis B46 and B. subtilis B315. The activity of antibiosis was tested by amylase activity enzyme and than it was analyzed using FTIR (Fourier Transform-infra Red). Result of the research showed that B. subtilis B315 could suppress R. solanacearum growth with 14 mm inhibition zone. Antibiosis activity of B. subtilisB315 as biological agents was showed by the production of amylase enzyme by activity of 0,802 unit/ml. Analysis by FTIR was showed by the production of compound group of alkane, aldehyde, ketones, carboxylic acid, esther, amina, and amida

Bioefficacy of Bacillus subtilis against root knot nematode Meloidogyne incognita (Kofoid and White) Chitwood in tomato

An investigation was conducted for the management of root knot nematode Meloidogyne incognita (Kofoid and White) Chitwood infesting tomato through the application of bio-control agent like Bacillus subtilis, Trichoderma harzianum and Pseudomonas fluorescens. Experiment result revealed that minimum no. of galls/25seedlings (17.50) and maximum seedling height (27.6cm) were observed in Bacillus subtilis @50g/m2 in nursery bed + B. subtilis @ 5kg along with 2.5 tons of FYM/ ha. The highest weight/25seedlings (69.50g) was noticed in the B. subtilis @50g/m2 in nursery bed + B. subtilis 2.5kg along with 2.5 tons of FYM/ha. The highest growth of the plant at 45 DAT (49.2cm) and at harvest (81.2cm) and maximum fresh (711.3g) and dry weight (265g) was found in B. subtilis @50g/m2 in nursery bed + B. subtilis 2.5kg along with 2.5 tons of FYM/ha. B. subtilis @50g/m2 in nursery bed + B. subtilis 2.5kg along with 2.5 tons of FYM/ha exhibited lowest gall index (1.2/plant) and highest reduction of nematode population and provided highest yield of tomato fruits (335.75q/ha)

Aktivitas Siderofor Bacillus Subtilis sebagai Pemacu Pertumbuhan dan Pengendali Patogen Tanaman Terung

Siderophore activity of Bacillus subtilis as plant growth promoters and biological control agent of eggplants pathogens. The aims of this research were to identify the siderophores of B. subtilis, to assess its activities as plant growth promoters and biological control agent of eggplants pathogens. Five isolates of B. subtilis i.e.B46, B209, B211, B298 and B 315 grown on SDCASA medium. The isolate which showed the best siderophores production was then further studied on its ability as a growth promoter on eggplants in two soil types with different Fe content. The inhibitory test was conducted against two kinds of pathogens, namely Colletotrichum sp. and Ralstonia solanacearum. The greenhouse experiment was arranged using a factorial completely randomized block design. The first factor was the B. subtilis (B. subtilis B298 and without B. subtilis B298), second factor was the type of soil (Ultisol and Andisol). The variables measured were Fe uptake by plants, plant growth parameters on eggplant i.e. height, leaf number, root length, root volume, weight of fresh and dried shoot as well as fresh and dry root, percentage of inhibition to fungal and bacterial eggplant pathogens. The results showed that the five isolates of B. subtilis were able to produce siderophores as catecholate and hydroxamate types. The best siderophore production was showed by B. subtilis B298. The ability of B. subtilis B298 in accelerating the growth of plants was indicated by the increased of uptake Fe, plant height, leaf number, root volume, weight of dried plants by 45.62%, 25.48%, 19.45%, 41.10% and 34.89% respectively. The inhibition to the fungal and bacterial eggplant pathogens best shown by the isolates of B. subtilis B298 with 55.4% and 22 mm respectively

Identification and characterization of the dif Site from Bacillus subtilis

Bacteria with circular chromosomes have evolved systems that ensure multimeric chromosomes, formed by homologous recombination between sister chromosomes during DNA replication, are resolved to monomers prior to cell division. The chromosome dimer resolution process in Escherichia coli is mediated by two tyrosine family site-specific recombinases, XerC and XerD, and requires septal localization of the division protein FtsK. The Xer recombinases act near the terminus of chromosome replication at a site known as dif (Ecdif). In Bacillus subtilis the RipX and CodV site-specific recombinases have been implicated in an analogous reaction. We present here genetic and biochemical evidence that a 28-bp sequence of DNA (Bsdif), lying 6° counterclockwise from the B. subtilis terminus of replication (172°), is the site at which RipX and CodV catalyze site-specific recombination reactions required for normal chromosome partitioning. Bsdif in vivo recombination did not require the B. subtilis FtsK homologues, SpoIIIE and YtpT. We also show that the presence or absence of the B. subtilis SPβ-bacteriophage, and in particular its yopP gene product, appears to strongly modulate the extent of the partitioning defects seen in codV strains and, to a lesser extent, those seen in ripX and dif strains