• Title, Summary, Keyword: Bacillus subtilis

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Purification and Characterization of Streptococcus mutans Cell Wall Hydrolase from Bacillus subtilis YL-1004

  • OHK, SEUNG-HO;YUN-JUNG YOO;DONG-HOON BAI
    • Journal of Microbiology and Biotechnology
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    • v.11 no.6
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    • pp.957-963
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    • 2001
  • Bacillus subtilis YL-1004 was isolated from soil for the development of agents to control dental caries. This strain produced an extracellular lytic enzyme that hydrolyzed the Streptococcus mutans cell wall. The lytic enzyme was purified to homogeneity by affinity chromatography and gel permeation chromatography to give a single band on SDS-PAGE and non-denaturing polyacrylamide gel electrophoresis. The molecular weight of the enzyme was deduced from SDS-PAGE and gel chromatography to be 38 kDa and the PI to be 4.3 from isoelectric focusing. Sirty $\%$ of its lytic activity remained after incubation at $50^{\circ}C$ for 30 min, and its optimal temperature was $37^{\circ}C$ . The enzyme showed its highest activity at pH 8.0 and was stable at pHs ranging from 4.0 to 9.0. Treatment with several modifiers showed that a cysteine residue was involved in the active site of the enzyme. This lytic enzyme from Bacillus subtilis YL-1004 exhibited specificity towards Streptococci and also showed autolytic activity on Bacillus subtilis YL-1004.

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Cloning of Fibrinolytic Enzyme Gene from Bacillus subtilis Isolated from Cheonggukjang and Its Expression in Protease-deficient Bacillus subtilis Strains

  • Jeong, Seon-Ju;Kwon, Gun-Hee;Chun, Ji-Yeon;Kim, Jong-Sang;Park, Cheon-Seok;Kwon, Dae-Young;Kim, Jeong-Hwan
    • 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.

Changes of Taste Components and Palatability during Chunggugjang Fermentation by Bacillus subtilis DC-2 (Bacillus subtilis DC-2를 이용한 청국장 발효과정 중 맛성분 및 기호도의 변화)

  • 정영건;최웅규;손동화;지원대;임무혁;최종동
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.5
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    • pp.840-845
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    • 1998
  • This study was conducted to produce the high quality of chunggugjang. The taste compounds of chunggugjang produced with Bacillus subtilis DC-2, pigment producing bacterium, were analysed, and palatability of chunggugjang was compared to that of commercial chunggugjang. Among the volatile organic acids, the contentof acetic acid was contained more than any other volatile organic acid. The major nonvolatile organic acid was lactic acid, followed by oxalic acid and citric acid. Tartaric acid was not detected. In case of free sugars, raffinose was sharply decreased between 72 and 96 hours after fermentation. Free amino acid was increased to 20 folds at 48 hours after fermentation compared to that of stemed soybean. As a result of sensory test, it was founded that the chunggujang fermented by Bacillus subtilis DC-2 was suitable to produce for commercial purpose.

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Fermentation Characteristics of Soybean Yogurt by Mixed Culture of Bacillus sp. and Lactic Acid Bacteria (고초균과 유산균의 혼합배양에 의한 두유 요구르트의 발효 특성)

  • Yang, Ming;Kwak, Jung Soon;Jang, Seri;Jia, Yuan;Park, Inshik
    • The Korean Journal of Food And Nutrition
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    • v.26 no.2
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    • pp.273-279
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    • 2013
  • The microorganisms producing high protease activity and acid producing ability were isolated from Chunggukjang and kimchi, which were identified as Bacillus subtilis and Lactobacillus planetarum by morphological, biochemical and nutrient requirement. The attempt was made to produce soybean milk yoghurt by using the isolated microorganisms. The mixed culture of Bacillus subtilis and Lactobacillus plantarum exhibited the lowest pH value of 4.23 and highest titratable acidity of 0.88% compared to those of single cultures at $37^{\circ}C$ for 32 hrs, and their total viable count was $4.09{\times}10^8$ $cfu/m{\ell}$. The ${\alpha}$-amylase activity was the highest in culture of Bacillus subtilis after incubation for 24 hrs, while protease activity was most produced in mixed culture of Bacillus subtilis and Lactobacillus plantarum. The amounts of reducing sugars were steadily decreased as soy milk fermentation progressed.

Production of Biosurfactant Lipopeptides Iturin A, Fengycin, and Surfactin A from Bacillus subtilis CMB32 for Control of Colletotrichum gloeosporioides

  • Kim, Pyoung-Il;Ryu, Jae-Won;Kim, Young-Hwan;Chi, Youn-Tae
    • Journal of Microbiology and Biotechnology
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    • v.20 no.1
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    • pp.138-145
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    • 2010
  • A bacterial strain isolated from soil for its potential to control the anthracnose disease caused by Colletotrichum gloeosporioides was identified as a Bacillus subtilis. Bacillus subtilis CMB32 produced antifungal agents on M9 broth at $30^{\circ}C$. Biosurfactant lipopeptides produced by Bacillus subtilis CMB32 were precipitated by adjusting to pH 2 and extracting using chloroform/methanol, and then were purified using column chromatography and reverse-phase HPLC. The molecular masses of the lipopeptides were estimated by MALDI-TOF mass spectrometry as (a) 1,080, (b) 1,486, and (c) 1,044 Da, respectively. They had cyclic structures and amino acid compositions of (a) Pro, Asx, Ser, Tyr, Glx, (b) Glx, Tyr, Thr, Ala, Pro, lie, and (c) Glx, Leu, Val, Asx, respectively. Further analysis revealed that Bacillus subtilis CMB32 produced three antifungal lipopeptides: (a) iturin A, (b) fengycin, and (c) surfactin A.

Bacterial Surface Display of Levansucrase of Zymomonas mobilis Using Bacillus Subtilis Spore Display System (고초균 포자를 이용한 Zymomonas mobilis 유래의 levansucrase 표면 발현)

  • Kim, June-Hyung;Choi, Soo-Keun;Jung, Heung-Chae;Pan, Jae-Gu;Kim, Byung-Gee
    • KSBB Journal
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    • v.26 no.3
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    • pp.243-247
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    • 2011
  • Using Bacillus subtilis spore display system, with cotG as an anchoring motif, levansucrase from Zymomonas mobilis, was displayed on the outer surface of Bacillus subtilis spore. Flow cytometry of DB104 (pSDJH-cotG-levU) spore, proved the surface localization of CotG-LevU fusion protein on the spore compared to that of DB104. Enzymatic activity of DB104 (pSDJH-cotG-levU) spore showed more than 1.5 times higher levansucrase specific activity compared to that of the host spore, which is a remarkable increase of enzymatic activity considering the existence of sacA (sucrase) and sacB (levansucrase) in the Bacillus subtilis chromosome. The spore integrity, revealed by sporulation frequency test after heat and lysozyme treatment of spore, did not changed at all in spite of the CotG-LevU fusion protein incorporation into the spore coat layer during spore formation process. These data prove again that Bacillus subtilis spore could be considered as good live immobilization vehicle for efficient bioconversion process.

Cloning and Strong Expression of a Bacillus subtilis WL-3 Mannanase Gene in B. subtilis

  • Yoon, Ki-Hong;Lim, Byung-Lak
    • Journal of Microbiology and Biotechnology
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    • v.17 no.10
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    • pp.1688-1694
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    • 2007
  • A gene encoding the mannanase of Bacillus subtilis WL-3, which had been isolated from Korean soybean paste, was cloned into Escherichia coli and the nucleotide sequence of a 2.7-kb DNA fragment containing the mannanase gene was subsequently determined. The mannanase gene, designated manA, consisted of 1,080 nucleotides encoding a polypeptide of 360 amino acid residues. The deduced amino acid sequence was highly homologous to those of mannanases belonging to glycosyl hydrolase family 26. The manA gene was strongly expressed in B. subtilis 168 by cloning the gene downstream of a strong B. subtilis promoter of plasmid $pJ27{\Delta}88U$. In flask cultures, the production of mannanase by recombinant B. subtilis 168 reached maximum levels of 300 units/ml and 450 units/ml in LB medium and LB medium containing 0.3% locust bean gum, respectively. Based on the zymogram ofthe mannanase, it was found that the mannanase produced by recombinant B. subtilis could be maintained stably without proteolytic degradation during the culture time.

Production and Properties of a Bacillus subtilis Mannanase from Recombinant Lactobacillus paracasei (재조합 Lactobacillus paracasei로부터 Bacillus subtilis의 Mannanase 생산과 효소특성)

  • Yoon, Ki-Hong
    • Microbiology and Biotechnology Letters
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    • v.40 no.3
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    • pp.186-189
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    • 2012
  • A gene coding for mannanase (manA) from Bacillus subtilis was introduced into a shuttle vector pGK12 between Escherichia coli, B. subtilis and Lactobacillus paracasei. As a result of transferring the resultant plasmid, designated pGK12M3, into three different strains, the manA gene was found to be expressed in L. paracasei as well as in B. subtilis and E. coli. In a 4 L fermentor culture, the production of mannanase by recombinant L. paracasei (pGK12M3) reached a maximum level of 5.4 units/ml in an MRS medium with a fixed pH 6.5. Based on the zymogram of mannanase, it is assumed that mannanase produced by recombinant L. paracasei is not maintained stably with proteolytic degradation. The optimal temperature and thermostability of mannanase produced by recombinant L. paracasei were also found to be different from those of enzymes produced by B. subtilis.

Characteristics of Chunggugjant Produced by Bacillus subtilis DC-2 (Bacillus subtilis DC-2로 제조한 청국장의 특성)

  • 정영건;최웅규;지원대
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.5
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    • pp.846-851
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    • 1998
  • Characteristics of chunggugjang fermented by Bacillus subtilis DC-2, a pigment producing bacterium, were investigated. More water soluble browning materials were produced with fermentation time. The pH was gradually alkalized. The contents of amino nitrogen were extraordinarily increased with fermentation time. Both strength and hardness were gradually decreased during fermentation. Total 30 volatile compounds were identified in the chunggugjang fermented by B. subtilis DC-2. The pyrazines were detected more than any other compounds. The good aroma of the chunggujang fermented by B. subtilis DC-2 was considered to be contributed by tetramethylpyrazine, trimethylpyrazine, 1-octen-3-ol, 2, 5-dimethylpyrazine and guaiacol.

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A Bacteriocin of 5-kDa in Size Secreted by Bacillus subtilis 168 (Bacillus subtilis 168 균주가 분비하는 5 kDa 크기의 Bacteriocin)

  • Kwon, Gun-Hee;Lee, Hwang-A;Kim, Jeong-Hwan
    • Microbiology and Biotechnology Letters
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    • v.38 no.2
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    • pp.163-167
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    • 2010
  • Bacillus subtilis 168 secreted antimicrobial substance(s) into culture medium and culture supernatant inhibited growth of some Gram positive bacteria. B. cereus and Listeria monocytogenes were the most sensitive organisms. The antimicrobial activity was destroyed when culture supernatant was treated by protease and proteinase K, indicating the proteinous nature of the substance (bacteriocin). The molecular weight of the bacteriocin was estimated to be 5 kDa by Tricine SDS-PAGE. B. cereus ATCC 14579 cells were killed when exposed to the bacteriocin, indicating that the mode of inhibition was bacteriocidal. These results show that B. subtilis 168 could be useful as a starter for fermented foods such as cheonggukjang where B. cereus contamination is a major concern.