• Microbiology and Biotechnology Letters
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• v.30 no.3
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• pp.206-209
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• 2002

For the expression of CGTase gene(cgtS) kom Bacillus stearothemophilus NO2 in Saccharomyces cerevisiae, cgtS gene was subcloned into the Eschepichia coll-yeast shuttle vector, pVT103-U. The constructed plasmid, pVT-CGTS was introduced to 5. cemi-siae 2805 cell, and then the cgtS gene under the control of adhl promoter was successfully expressed in the yeast transformant and 87% of the total activity was detected into the fermentation medium. Therefore, the signal peptide of B. stearothemephilus NO2 CeTase showed high secretion efficiency in 5. cerevisiae. Optimal conditions of the recombinant yeast cell f3r expression of CGTase was achieved, when 5. cerevisiae 2805/pv7-CGTS was cultivated on YP medium at 2% dextrose, pH 5.5,$30^{\circ}C$ and the expression level of CGTase was 0.624units/mL for 48 h culture.

• Journal of Microbiology and Biotechnology
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• v.25 no.7
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• pp.963-977
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• 2015

The well-characterized gram-positive bacterium Bacillus subtilis is an outstanding industrial candidate for protein expression owing to its single membrane and high capacity of secretion, simplifying the downstream processing of secretory proteins. During the last few years, there has been continuous progress in the illustration of secretion mechanisms and application of this robust host in various fields of life science, such as enzyme production, feed additives, and food and pharmaceutical industries. Here, we review the developments of Bacillus subtilis as a highly promising expression system illuminating strong chemical- and temperatureinducible and other types of promoters, strategies for ribosome-binding-site utilization, and the novel approach of signal peptide selection. Furthermore, we outline the main steps of the Sec pathway and the relevant elements as well as their interactions. In addition, we introduce the latest discoveries of Tat-related complex structures and functions and the countless applications of this full-folded protein secretion pathway. This review also lists some of the current understandings of ATP-binding cassette transporters. According to the extensive knowledge on the genetic modification strategies and molecular biology of Bacillus subtilis, we propose some suggestions and strategies for improving the yield of intended productions. We expect this to promote striking future developments in the optimization and application of this bacterium.

• The Plant Pathology Journal
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• v.31 no.2
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• pp.195-201
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• 2015

Plant growth promoting rhizobacteria (PGPR) are known to confer disease resistance to plants. Bacillus sp. JS demonstrated antifungal activities against five fungal pathogens in in vitro assays. To verify whether the volatiles of Bacillus sp. JS confer disease resistance, tobacco leaves pre-treated with the volatiles were damaged by the fungal pathogen, Rhizoctonia solani and oomycete Phytophthora nicotianae. Pre-treated tobacco leaves had smaller lesion than the control plant leaves. In pathogenesis-related (PR) gene expression analysis, volatiles of Bacillus sp. JS caused the up-regulation of PR-2 encoding ${\beta}$-1,3-glucanase and acidic PR-3 encoding chitinase. Expression of acidic PR-4 encoding chitinase and acidic PR-9 encoding peroxidase increased gradually after exposure of the volatiles to Bacillus sp. JS. Basic PR-14 encoding lipid transfer protein was also increased. However, PR-1 genes, as markers of salicylic acid (SA) induced resistance, were not expressed. These results suggested that the volatiles of Bacillus sp. JS confer disease resistance against fungal and oomycete pathogens through PR genes expression.

• Journal of Microbiology and Biotechnology
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• v.18 no.6
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• pp.1033-1039
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• 2008

A 3-kb HindIII fragment bearing the cry6Aa2 gene and the adjacent and intergenic regions was cloned from Bacillus thuringiensis strain YBT-1518. Two open reading frames (ORFs), namely, orf1 (termed cry6Aa2) and orf2 that were separated by an inverted-repeat sequence were identified. orf1 encoded a 54-kDa protein that exhibited high toxicity to the plant-parasitic nematode Meloidogyne hapla. The orf2 expression product was not detected by SDS-PAGE, but its mRNA was detected by RT-PCR. The orf2 coexpressed with orf1 at a high level in the absence of the inverted-repeat sequence, whereas, the expression level of otfl was decreased. When orf2 was mutated, the level of orf1 expression was enhanced obviously. In conclusion, the inverted-repeat sequence disturbs orf2 expression, and the orf2 downregulates orf1 expression. This is an example of novel negative regulation in B. thuringiensis and a potential method for enhancing the expression level of cry genes.

• Journal of Microbiology and Biotechnology
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• v.17 no.6
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• pp.1018-1023
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• 2007

Bacillus subtilis CH3-5 was isolated from cheonggukjang prepared according to traditional methods. CH3-5 secreted at least four different fibrinolytic proteases (63, 47, 29, and 20 kDa) into the culture medium. A fibrinolytic enzyme gene, aprE2, encoding a 29kDa enzyme was cloned from the genomic DNA of CH3-5, and the DNA sequence determined. aprE2 was overexpressed in heterologous B. subtilis strains deficient in extracellular proteases using a E. coli-Bacillus shuttle vector. A 29 kDa AprE2 band was observed and AprE2 seemed to exhibit higher activities towards fibrin rather than casein.

• Journal of Microbiology and Biotechnology
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• v.25 no.9
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• pp.1519-1527
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• 2015

Biogenic amines in some food products present considerable toxicological risks as potential human carcinogens when consumed in excess concentrations. In this study, we investigated the degradation of the biogenic amines histamine and tyramine and the presence of genes encoding histidine and tyrosine decarboxylases and amine oxidase in Bacillus species isolated from fermented soybean food. No expression of histidine and tyrosine decarboxylase genes (hdc and tydc) were detected in the Bacillus species isolated (B. subtilis HJ0-6, B. subtilis D'J53-4, and B. idriensis RD13-10), although substantial levels of amine oxidase gene (yobN) expression were observed. We also found that the three selected strains, as non-biogenic amineproducing bacteria, were significantly able to degrade the biogenic amines histamine and tyramine. These results indicated that the selected Bacillus species could be used as a starter culture for the control of biogenic amine accumulation and degradation in food. Our study findings also provided the basis for the development of potential biological control agents against these biogenic amines for use in the food preservation and food safety sectors.

• Food Science and Biotechnology
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• v.16 no.4
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• pp.655-658
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• 2007

Bacillus polyfermenticus SCD was transformed by the recombinant shuttle vector for Bacillus and Escherichia coli containing 3 antibiotic resistant genes and an ${\alpha}$-amylase gene from Bifidobacterium adolescentis Int57. The ${\alpha}$-amylase gene fused to a secretion sequences was expressed under the control of the promoter of amylase gene from B. subtilis var. natto. The recombinant plasmid was maintained stably in the transformants producing the ${\alpha}$-amylase. The enzyme was secreted to outside of the cell and showed the similar enzyme activity as that of Bacillus subtilis BD170 under the same conditions of pH and growth temperature. Because of the relatively easy transformation and the secretion of the enzyme, the transformants of B. polyfermenticus SCD may give a new strategy in the production of foreign genes.

• Journal of Sericultural and Entomological Science
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• v.35 no.1
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• pp.36-42
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• 1993

Expression of insecticidal protein by fusion product of truncated HD-1[CryIA(a)] N-terminal and HD-73[CryIA(c)] C-Terminal fragment of Bacillus thruingiensis subsp. kurstaki was investigate. Immunological analysis of transformants by using polyclonal antisera raised against the whole-crystal protein of HD-1 revealed that SK4 and SK5 were observed cross-reaction with polypeptides of 77-kDa and 105-kDa, respectively. Bioassay of the transformant pSK5 to Plutella maculipennis and Heliothis assulta were 96% and 97%, respectively.

• Microbiology and Biotechnology Letters
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• v.32 no.3
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• pp.212-217
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• 2004

The gene coding for mannanase from Bacillus subtilis WL-7, a number of glycosyl hydrolase family 26, was hyperexpressed in Escherichia coli. Two recombinant plasmids, pE7MAN and pENS7, were constructed by introducing the complete mannanase gene and the mature mannanase gene lacking N-terminal signal peptide region into a expression vector pET24a(＋), respectively. The level of mannanase produced by E. coli BL21 (DE3) carrying pENS7, which included the mature mannanase gene, was considerably higher than that by E. coli BL21 (DE3)/pE7MAN. Almost mannanase produced by the recombinant E. coli carrying pENS7 at growth temperature of $37^{\circ}C$ existed as inactive enzyme of insoluble form. Growth at temperature below $31^{\circ}C$ increased the soluble fraction of mannanase having catalytic activity in the recombinant E. coli cells. The highest productivity of active mannanase was observed in cell-free extract of the recombinant E. coli grown at growth temperature ranging from $25^{\circ}C$ to $28^{\circ}C$, while mannanase activity per soluble protein of the cell-free extract was highest in the cells grown at $^31{\circ}C$.

• The Plant Pathology Journal
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• v.25 no.2
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• pp.136-141
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• 2009

Marking biocontrol bacteria is an essential step to monitor bacterial behavior in natural environments before application in agricultural ecosystem. In this study, we presented the simple green fluorescent protein (GFP) reporter system driven by the promoter active in Bacillus species for tagging of the biocontrol bacteria. A constitutive promoter P43 from Bacillus subtilis was fused to an enhanced promoterless gfp gene by overlap extension PCR. The GFP expression was demonstrated by the high fluorescence intensity detected in B. subtilis and Escherichia coli transformed with the P43-gfp fusion construct, respectively. The GFP reporter system was further investigated in two bacterial biocontrol strains B. licheniformis and Pseudomonas fluorescens. When the reconstructed plasmid pWH34G was introduced into B. licheniformis, GFP level measured with the fluorescence intensity in B. licheniformis was almost equivalent to that in B. subtilis. However, GFP expression level was extremely low in other biocontrol bacteria P. fluorescens by transposon based stable insertion of the P43-gfp construct into the bacterial chromosome. This study provides information regarding to the efficient biomarker P43-gfp fusion construct for bio-control Bacillus species.