• Journal of Microbiology and Biotechnology
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• 제5권1호
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• pp.18-21
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• 1995

Endoglucanase gene of Pseudomonas sp. LBC505 was previously cloned in pUCl9 to yield plasmid pLC1. overproduction of endoglucanase was attempted by following ways. First, the endoglucanase gene of Pseudomonas sp. LBC505 cloned in pUCl9(pLC1) was tandemly inserted, step by step, into a expression vector pKK223-3 in a directly repeated form to enhance productivity of endoglucanase. Escherichia coli containing pKCC30 among the resulting plasm ids showed the higher yield of the endoglucanase. Ecoli harboring pKCC30 which had three inserted endoglucanase genes expressed about 12.3 times as much CMCase activity as Ecoli harboring pLCl. Second, the endoglucanase gene was subcloned into Bacillus subtilis expression vector pgnt41 for both overproduction and extracellular secretion of the endoglucanase. A resulting plasmid pgntc15 in Bacillus subtilis expressed 4.3-fold higher levels of CMCase activity than that of E.coli harboring pLCl and the endoglucanase produced was entirely secreted into the culture medium.

• Journal of Microbiology and Biotechnology
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• 제28권6호
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• pp.1030-1036
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• 2018

Bacillus strains produce various types of antibiotics, and random mutagenesis has traditionally been used to overproduce these natural metabolites. However, this method leads to the accumulation of unwanted mutations in the genome. Here, we rationally designed a single nucleotide substitution in the degU gene to generate a B. subtilis strain displaying increased plipastatin production in a foreign DNA-free manner. The mutant strain (BS1028u) showed improved antifungal activity against Pythium ultimum. Notably, pps operon deletion in BS1028u resulted in complete loss of antifungal activity, suggesting that the antifungal activity strongly depends on the expression of the pps operon. Quantitative real-time PCR and lacZ assays showed that the point mutation resulted in 2-fold increased pps operon expression, which caused the increase in antifungal activity. Likewise, commercial Bacillus strains can be improved to display higher antifungal activity by rationally designed simple modifications of their genome, rendering them more efficient biocontrol agents.

• 한국식품과학회지
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• 제23권1호
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• pp.31-36
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• 1991

고온, 알칼리성 Bacillus sp. F204의 CMCase 유전자를 pUC19의 HindIII부위에 연결하여 전이된 E.coli 형질전환체 중 2개의 재조합 플라스미드 즉, pBC191과 pBC192를 선발하였는데, 이들은4.6 Kb와 5.8 Kb HindIII 절편을 각각 함유하고 있었다. pBC191의 4.6 Kb HindIII 절편을 BamHI, EcoRI, KpnI, PvuII 부위가 각각 1개씩 존재하였다. Dioxigenin-labeled deoxyuridin-triphosphate에 4.6 Kb 절편을 표식한 것을 probe로 하여 상동성을 검정한 결과 모균주와 강한상동성이 없었고, 면역학적 실험에서도 Bacillus sp. F204 유래임이 인정되었다. pBC191의 4.6 Kb 절편을 E.coli의 발현 벡타인 pKK223-3과 Bacillus vector인 pGR71에 연결시켜 구축한 pKC231과 pGC711은 각각 pBC191에 비하여 효소활성이 3.2배와 2.8배정도 증가되었으며, 그리고 E.coli에서는 대부분 세포내와 periplasmic 분획에서 검출되었다. 기질 특이성을 조사한 결과에 의하면 pBC191과 pBC192는 CMCase gene을 코딩하고 있는 것으로 나타났다.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2003년도 International Meeting of the Microbiological Society of Korea
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• pp.77-79
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• 2003

Current therapeutic strategies far anthrax have had no significant impact on anthrax mortality over the last several decades. This study used a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) discovery platform to generate protein expression profiles in search of overexpressed proteins in murine macrophage cells (RAW264.7) which infected with Bacillus anthracis spores as potentially novel molecular targets. Two differentially expressed proteins were identified in infected murine macrophage cells as Syndapin and CDC46, respectively. Syndapins are potential links between the cortical actin cytoskeleton and endocytosis. Other two proteins were identified from murine macrophage cells infected with avirulent spores as ITBG-2 (CD18) and HSPA5, respectively. These data demonstrate the feasibility of using a MALDI-TOF platform to generate protein expression profiles and identify potential molecular targets for anthrax therapeutics.

• 한국미생물·생명공학회지
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• 제17권2호
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• pp.154-159
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• 1989

Chromosomal DNA fragments of Bacillus sp. YA-14 isolated from soil as a potent xylan hydrolyzing bacterium, were ligated to a vector plasmid, pBR322, and used to transfer Escherichia coli HB101 cells. The recombinant plasmid pYDC21 was found to enable the transformants to produce xylanase. pYDC21 was found to contain the 3 kb HindIII fragment originated from the Bacillus sp. YA-14 chromosomal DNA by southern hybridization. The optimum temperature and pH for the reaction of xylanse produced by E. coli (pYDC21) were appeared at 50$_7$C and pH 7.0, respectiveiy. the xylanase enzyme was stable between pH 5.0 and 7.0 and maintained stably up to 4$0^{\circ}C$.

• 한국미생물·생명공학회지
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• 제23권4호
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• pp.390-396
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• 1995

Bacillus sphaericus 1593 is a larvicidal toxin-producing mosquitocidal bacterium. The toxin contains a parasporal crystalline inclusion which is composed of a protein that is activated under alkaline condition. To enhance alkaline environment around toxin protein, cryptic plasmid cured, B. sphaericus 1593 was transformed by the Bacillus pasteurii urease gene which generate ammonia from urea. Transformant produced urease at about 80% more than wild type strain. B. sphaericus 1593, and the urease gene was stably maintained. It also produced crystalline toxin protein at the same level as the wild type strain B. sphaericus 1593.

• 한국미생물·생명공학회지
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• 제49권3호
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• pp.289-297
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• 2021

Bacillus velezensis CJ1, showing significant fibrinolytic activity, was isolated from Myeolchi Jeotgal, a popular Korean fermented seafood. When B. velezensis CJ1 was grown on four different culture media, the culture on the Luria-Bertani (LB) broth showed the highest fibrinolytic activity (102.94 mU/μl) at 48 h. LB was also the best medium for growth. SDS-PAGE of culture supernatant showed four major bands, 38, 35, 27, and 22 kDa in size. Fibrin zymography showed four active bands, 50, 47, 40, and 30 kDa in size. A gene homologous to aprE of the Bacillus species was cloned by PCR. DNA sequencing showed that aprECJ1 can encode a protease consisting of 382 amino acids. The translated amino acid sequence of AprECJ1 showed high identity values with those of B. velezensis strains and other Bacillus species. The aprECJ1 gene was introduced into B. subtilis WB600 using an E. coli-Bacillus shuttle vector, pHY300PLK, and overexpressed. A 27 kDa band corresponding to the mature form of AprECJ1 was produced and confirmed by SDS-PAGE and fibrin zymography. B. subtilis WB600 [pHYaprECJ1] showed 1.8-fold higher fibrinolytic activity than B. velezensis CJ1 at 48 h.

• Journal of Microbiology and Biotechnology
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• 제19권2호
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• pp.194-203
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• 2009

$HpaG_{Xooc}$, from rice pathogenic bacterium Xanthomonas oryzae pv. oryzicola, is a member of the harpin group of proteins, eliciting hypersensitive cell death in non-host plants, inducing disease and insect resistance in plants, and enhancing plant growth. To express and secret the $HpaG_{Xooc}$ protein in Bacillus subtilis, we constructed a recombinant expression vector pM43HF with stronger promoter P43 and signal peptide element nprB. The SDS-PAGE and Western blot analysis demonstrated the expression of the protein $HpaG_{Xooc}$ in B. subtilis. The ELISA analysis determined the optimum condition for $HpaG_{Xooc}$ expression in B. subtilis WBHF. The biological function analysis indicated that the protein $HpaG_{Xooc}$ from B. subtilis WBHF elicits hypersensitive response(HR) and enhances the growth of tobacco. The results of RT-PCR analysis revealed that $HpaG_{Xooc}$ induces expression of the pathogenesis-related genes PR-1a and PR-1b in plant defense response.

• Journal of Microbiology and Biotechnology
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• 제28권12호
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• pp.2046-2056
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• 2018

Phospholipase D has great commercial value due to its transphosphatidylation products that can be used in the food and medicine industries. In order to construct a strain for use in the production of PLD, we employed a series of combinatorial strategies to increase PLD expression in Bacillus subtilis WB600. These strategies included screening of signal peptides, selection of different plasmids, and optimization of the sequences of the ribosome-binding site (RBS) and the spacer region. We found that using the signal peptide amyE results in the highest extracellular PLD activity (11.3 U/ml) and in a PLD expression level 5.27-fold higher than when the endogenous signal peptide is used. Furthermore, the strain harboring the recombinant expression plasmid pMA0911-PLD-amyE-his produced PLD with activity enhanced by 69.03% (19.1 U/ml). We then used the online tool \RBS Calculator v2.0 to optimize the sequences of the RBS and the spacer. Using the optimized sequences resulted in an increase in the enzyme activity by about 26.7% (24.2 U/ml). In addition, we found through a transfer experiment that the retention rate of the recombinant plasmid after 5 generations was still 100%. The final product, phosphatidylserine (PS), was successfully detected, with transphosphatidylation selectivity at 74.6%. This is similar to the values for the original producer.

• Journal of Microbiology and Biotechnology
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• 제21권6호
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• pp.574-581
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• 2011

A Gram-positive bacterium was isolated from the saline soils of Jangpura (U.P.), India, and showed high-level of radiation-resistant property and survived upto 12.5 kGy dose of gamma radiation. The 16S rDNA sequence of this strain was examined, identified as Bacillus sp. strain HKG 112, and was submitted to the NCBI GenBank (Accession No. GQ925432). The mechanism of radiation resistance and gene level expression were examined by proteomic analysis of whole-cell extract. Two proteins, 38 kDa and 86.5 kDa excised from SDS-PAGE, which showed more significant changes after radiation exposure, were identified by MALDI-TOF as being flagellin and S-layer protein, respectively. Twenty selected 2-DE protein spots from the crude extracts of Bacillus sp. HKG 112, excised from 2- DE, were identified by liquid chromatography mass spectrometry (LC-MS) out of which 16 spots showed significant changes after radiation exposure and might be responsible for the radiation resistance property. Our results suggest that the different responses of some genes under radiation for the expression of radiation-dependent proteins could contribute to a physiological advantage and would be a significant initial step towards a fullsystem understanding of the radiation stress protection mechanisms of bacteria in different environments.