• 미생물학회지
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• 제45권2호
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• pp.185-192
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• 2009

Bacillus subtilis 028-1 균주는 청국장 발효에 사용하는 균주로 Staphylococcus sp. LS2 뿐만 아니라 여러 yeast 균주의 생장을 억제하는 항생물질을 생산하며, soybean meal 2%와 maltose와 같은 이당류를 1% 첨가하여 15~18시간 진탕 배양하였을 때 최대의 항생물질 생산을 보였으며 배지의 pH는 6.5 이하였다. 항생물질의 활성은 약염기성 조건에서 극대화되었으며, $100^{\circ}C$에서 20분간 가열하여도 활성은 크게 감소하지 않았고, 실온 보관 시 한 달 이상 효과가 지속되며 chymotrypsin과 papain 같은 단백질 분해효소 처리에 의해 서서히 활성이 줄어들었다. 투석에 의해 항생물질의 분자량을 측정한 결과 1,000에서 500 dalton 사이인 것으로 나타났으며 항미생물 효과는 있으나 fibrin 분해 능력이 없으므로 surfactin이 아닌 iturin 계열의 peptide성 항생물질로 보인다.

• 미생물학회지
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• 제45권1호
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• pp.10-16
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• 2009

일부 그람양성세균들은 고온, 저온, 염, 에탄올, 산소와 영양분 고갈과 같은 다양한 스트레스 상태에 노출되면, 일반 스트레스반응(general stress response)에 의해서 일련의 스트레스 단백질군을 발현시켜 외부 스트레스를 극복하고 세균의 생존력을 증가시킨다. 비병원성균인 Bacillus subtilis의 일반 스트레스반응에 관해서는 많은 연구가 이루어져 있으므로 다른 균의 연구모델로 이용이 가능하다. 본 총설에서는 B. subtilis와 병원성균인 Listeria monocytogenes의 일반 스트레스반응의 유사성과 차이점을 B. subtilis를 모델로 하여 비교하였다. 두 균의 일반 스트레스반응은 대체 전사 인자인 ${\sigma}^B$ (alternative transcription factor sigma B)에 의해서 조절되고 신호전달 네트워크 또한 매우 유사하며, ${\sigma}^B$ 의존성 유전자들에 의해 150여 개의 스트레스 단백질들이 발현된다. 그러나 L. monocytogenes는 B. subtilis의 에너지 스트레스 신호 경로를 가지고 있지 않은 점과, 일반 스트레스반응에 의해 병독 유전자들(virulence genes)이 조절되는 것이 가장 큰 차이점이다. 그러므로 L. monocytogenes의 생리 및 병원성 규명을 위해서는 일반 스트레스반응에 관한 이해가 매우 중요하다.

• Applied Biological Chemistry
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• 제46권3호
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• pp.176-182
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• 2003

한국재래간장으로부터 혈전용해효소를 강하게 생산하는 균주를 선발하고 이를 Bacillus subtilis K7로 동정하였다. B. subtilis K7이 생산하는 혈전용해성 protease를 정제하여 분자량을 확인한 결과 21,500 Da이었다. 정제된 효소의 최적반응조건은 $40^{\circ}C$와 pH 9.0이었으며 pH 5.0라서 12.0까지 안정하고 $50^{\circ}C$에서 20분간 열처리한 후에도 50%이상의 효소활성을 가지며 EDTA, CDTA 및 iodoacetat에 실활하는 효소이었다. 이 효소의 fibrin에 대한 Km 값은 $1.8{\times}10^{-2}$ M이었다.

• 한국초지조사료학회지
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• 제17권3호
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• pp.239-248
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• 1997

This study was conducted to investigate the effects of antagonistic microorganisms, Bacillus spp., on growth of alfalfa(Medicag0 sativa L.) in repeated cultivation soil(RCS) and unrepeated cultivation soil(URCS). Alfalfa was established by seeding into pots 12 cm in diameter and 9 cm in depth containing 1 : 1 mixture of soil and vermiculite with antagonistic bacteria and pathogenic fungi. The growth experiment of alfalfa was conducted in pots in a vinyl house. The bacteria used in this study were Bacillus subtilis and hsants. B. subtilis was isolated and identified 60m forage rhizosphere soil and hsants isolated through cell fusion fiom B. subtilis 101 and B. thuringiensis. B. subtilis was named B. subtilis 101 and hsants named F -3 and F -8. From dark culture experimenf alfalfa was longer lived in treated soil with antagonistic bacteria than that in non-treated soil, and longer lived in URCS than that in RCS. However, alfalfa was shorter lived in RCS and URCS than that in autoclaved RCS. The number of leaves of alfalfa were positively affected by the inoculation of the antagonistic bacteria in both RCS and URCS. Dry weight of shoot and root was increased by the inoculation of the antagonistic bacteria(P< 0.05). However, the growth of alfalfa was decreased by the inoculation of the pathogenic hngi both RCS apd URCS.

• 농약과학회지
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• 제20권4호
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• pp.375-379
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• 2016

내장산 토양에서 분리한 미생물들의 젤라틴 및 고구마뿌리혹선충의 난낭 분해활성을 평가하였다. 활성이 우수한 3종의 균주는 16S rRNA 염기서열을 이용하여 분석하였으며, Bacillus subtilis KRB-5와 Bacillus amyloliquefaciens KRB-9, 10이 분리동정되었다. 고구마뿌리혹선충에 20일간 노출시킨 고추모종에 분리동정된 3종의 미생물을 90일동안 처리하고 난낭과 고추모종의 지상부 생육에 미치는 영향을 조사하였다. 실험결과 B. subtilis KRB-5을 처리한 군에서는 미생물 무처리 군 및 다른 미생물 처리 군과 비교하여 고구마뿌리혹선충의 난낭 수가 현저하게 감소하였으며, 고추의 지상부 생육도 개선되는 것을 확인하였다. 따라서 B. subtilis KRB-5 균주를 이용한 박과 작물에 대한 확대 효능 평가와 시설 재배지 현장 시험 등의 추가적인 연구는 활용할 필요할 것으로 사료된다.

• 한국식품영양과학회지
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• 제20권1호
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• pp.21-26
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• 1991

the Bacillus subtilis LY-353 which secretes the protease isolated from seafoods. The opti-mum culture condition for production of protease from B. subtilis LY-353 was as follows ; tem-perature 35$^{\circ}C$ pH 7.5 salt concentration 1.0% The purification steps involved ammonium sulfate fractionation DEAE-Sephadex A-50 column chromatography and Sephadex G-100 gel filtration A 7.33 fold purification and 6.55 yield of protease was obtained from culture broth, The optimum pH and temperature for the enzyme action were pH7.5 and 55$^{\circ}C$ respecti-bely.

• Journal of Microbiology and Biotechnology
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• 제24권2호
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• pp.188-196
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• 2014

Extracellular production of recombinant human bone morphogenetic protein-7 (rhBMP-7) was carried out through the fermentation of Bacillus subtilis. Three significant fermentation conditions and medium components were selected and optimized to enhance the rhBMP-7 production by using the response surface methodology (RSM). The optimum values of the three variables for the maximum extracellular production of rhBMP-7 were found to be 2.93 g/l starch, 5.18 g/l lactose, and a fermentation time of 34.57 h. The statistical optimization model was validated with a few fermentations of B. subtilis in shake flasks under optimized and unoptimized conditions. A 3-L jar fermenter using the shake-flask optimized conditions resulted in a higher production (413 pg/ml of culture medium) of rhBMP-7 than in a shake flask (289.1 pg/ml), which could be attributed to the pH being controlled at 6.0 and constant agitation of 400 rpm with aeration of 1 vvm.

• Journal of Microbiology and Biotechnology
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• 제10권2호
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• pp.275-280
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• 2000

The inulin fructotransferse (depolymerizing) (IFTase, EC 2.4.1.93) gene of Arthrobacter sp. A-6 was cloned and expressed in Escherichia coli and Bacillus subtilis. The IFTase gene consisted of an ORF of 1.311 nucleotides encoding a polypeptide of 436 amino acids containing a signal peptide of 31 amino acids in the N-terminus. The molecular mass of the IFTase based on the nucleotide sequence was calculated to be 46.116 Da. The recombinant E. coli $DH5{\alpha}$ cells expressing the Arthrobacter sp. A-6 IFTase gene produced most of the IFTase intracelularly. In contrast, the recombinant B. subtilis DB 104 carrying the IFTas gene on a B. subtilis-E. Coli expression vector secreted the IFTase into the culture fluid efficiently.

• Journal of Microbiology
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• 제43권3호
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• pp.272-276
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• 2005

Bacillus subtilis ATCC 6633 was grown in BHIB medium supplemented with $Mn^{2+}$ for 96 h at $37^{\circ}C$ in a shaker incubator. After removing the microbial biomass, a lipopeptide biosurfactant was extracted from the supernatant. Its structure was established by chemical and spectroscopy methods. The structure was confirmed by physical properties, such as Hydrophile-Lipophile Balance (HLB), surface activity and erythrocyte hemolytic capacity. The critical micelle concentration (cmc) and erythrocyte hemolytic capacity of the biosurfactant were compared to those of surfactants such as SDS, BC (benzalkonium chloride), TTAB (tetradecyltrimethylammonium bromide) and HTAB (hexadecyltrimethylammonium bromide). The maximum hemolytic effect for all surfactants mentioned was observed at concentrations above cmc. The maximum hemolytic effect of synthetic surfactants was more than that of the biosurfactant produced by B. subtilis ATCC 6633. Therefore, biosurfactant would be considered a suitable surface-active agent due to low toxicity to the membrane.

• Asian-Australasian Journal of Animal Sciences
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• 제30권9호
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• pp.1332-1339
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• 2017

Objective: This study investigated the effects of Bacillus subtilis CSL2 (B. subtilis CSL2) administration before Salmonella challenge on the fecal microbiota and microbial functionality of Hy-line Brown (HLB) laying hens. Methods: Fecal samples were collected from control (CON), Salmonella-infected (SAL) and Salmonella-infected, probiotic-treated (PRO) groups before and after Salmonella challenge for microbiome analysis using 16S rRNA gene pyrosequencing. Results: Infection with Salmonella led to decreased microbial diversity in hen feces; diversity was recovered with Bacillus administration. In addition, Salmonella infection triggered significant alterations in the composition of the fecal microbiota. The abundance of the phylum Firmicutes decreased while that of Proteobacteria, which includes a wide variety of pathogens, increased significantly. Bacillus administration resulted in normal levels of abundance of Firmicutes and Proteobacteria. Analysis of bacterial genera showed that Salmonella challenge decreased the population of Lactobacillus, the most abundant genus, and increased populations of Pseudomonas and Flavobacterium genera by a factor of 3 to 5. On the other hand, Bacillus administration caused the abundance of the Lactobacillus genus to recover to control levels and decreased the population of Pseudomonas significantly. Further analysis of operational taxonomic units revealed a high abundance of genes associated with two-component systems and secretion systems in the SAL group, whereas the PRO group had more genes associated with ribosomes. Conclusion: The results of this study indicate that B. subtilis CSL2 administration can modulate the microbiota in HLB laying hens, potentially acting as a probiotic to protect against Salmonella Gallinarum infection.