• Journal of Applied Biological Chemistry
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• v.61 no.1
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• pp.59-67
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• 2018

This study was conducted to isolate the cellulolytic bacteria able to grow on LB- Carboxymethyl cellulose (CMC) agar trypan blue medium from the mixed forest and Larix leptolepis stands. Three bacterial strains with high activity against both CMC and xylan were isolated. Both API kit test and 16S rRNA gene sequence analysis revealed that the three different isolates belong to the gene Bacillus. Therefore, the isolates named as Bacillus sp. EFL1, Bacillus sp. EFL2, and Bacillus sp. EFP3. The optimum growth temperature of Bacillus sp. EFL1, EFL2, and EFP3 were $37^{\circ}C$. The optimum temperature for CMCase and xylanase from Bacillus sp. EFL1 were $50^{\circ}C$. The optimum pH of Bacillus sp. EFL1 xylanase was pH 5.0 but the optimum pH of CMCase from Bacillus sp. EFL1 was pH 6.0. The optimum temperature of CMCase and xylanase from Bacillus sp. EFL2 was $60^{\circ}C$, respectively. The optimum pH of CMCase of Bacillus sp. EFL2 was 5.0, whereas xylanase showed high activity at pH 3.0-9.0. The optimum temperature for CMCase and xylanase of Bacillus sp. EFP3 was $50^{\circ}C$. The optimum pH for CMCase and xylanse was 5.0 and 4.0, respectively. CMCases from Bacillus sp. EFL1, EFL2, and EFP3 were thermally unstable. Although xylanase from Bacillus sp. EFL1 and EFP3 showed to be thermally unstable, xylanase from Bacillus sp. EFL2 showed to be thermally stable. Therefore, Bacillus sp. EFL2 has great potential for animal feed, biofuels, and food industry applications.

• Microbiology and Biotechnology Letters
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• v.30 no.4
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• pp.346-351
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• 2002

A bacterium producing the neutral pretense was isolated from soil, and was identified as Bacillus sp. DS-1 by 16S rRNA sequence comparison and biochemical determinations. The production of protease from Bacillus sp. DS-1 was increased 20% and 30% by the additions of 1% glucose and 1% yeast extract, respectively. The optimum pH and temperature for the protease activity were pH 7.0 and 55$^{\circ}C$. Bacillus sp. DS-1 produced a metalloprotease as a major protease in culture medium, since the pretense activity in culture supernatant was inhibited by the presence of 1 mM EDTA significantly.

• Applied Biological Chemistry
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• v.40 no.5
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• pp.369-374
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• 1997

An endochitosanase-producing bacterium was isolated from soil and identified as a strain of Bacillus sp. The isolate was gram positive, rod shape $(0.4-0.6{\times}1.6-2.2{\mu}m)$, endospore-forming, catalase positive, and mobility positive, and grown at pH 4.5-11.0 and upto $42^{\circ}C$ in the medium containing 2% NaCl. RAPD analysis of the DNA purified from the strain was also performed, and the chitosanase-producing strain was named as Bacillus sp. P16. The culture supernatant of the strain showed strong liquefaction activity and rapidly decreased viscosity of chitosan solution. By TLC and HPLC, chitooligosaccharides of DP 2-7 were separated and identified from the enzyme hydrolyzates of chitosan. The chitosanase from Bacillus sp. P16 was thus regarded as an endo-splitting type.

• Applied Biological Chemistry
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• v.42 no.3
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• pp.193-198
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• 1999

The optimal culture condition of Bacillus sp. P16 was investigated for production of an extracellular endo-splitting chitosanase. The best carbon and nitrogen sources for the chitosanase production were chitosan and tryptone, respectively. The best condition for the maximum activity was at $37^{\circ}C$ in a medium containing 0.5% powdered chitosan, 1% tryptone, and 1% NaCl(at initial pH 7.0) in a rotary shaker(200 rpm). In a jar fermenter, the culture duration shortened to $6{\sim}12$ hr for maximum activity and the enzyme activity increased about 100% compared with that of flask culture.

• Korean Journal of Food Science and Technology
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• v.38 no.3
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• pp.419-426
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• 2006

A thermophilic microorganism, strain JE 375, which produces a thermostable protease, was isolated from soil and compost in Korea. This gram-positive, rod-shaped, catalase positive, motility positive, and hemolysis ${\beta}$ containing organism was implicated in glucose fermentation, mannitol fermentation, xylose oxidation, aerobic activity and spore formation. The color of the colony was yellowish white. The temperature range for growth at pH 6.5 was between 55 and $70^{\circ}C$, with an optimum growth temperature of $65^{\circ}C$. This result confirmed the strain JE 375 as a thermophilic microorganism. The enzyme was produced aerobically at $65^{\circ}C$ during 20 hr in a medium (pH 6.5) containing 1% trypton. 1% maltose, 0.5% yeast extract and 1% NaCl. The 16S rDNA of strain JE 375 had 97.6% sequence similarity with the 16S rDNA of Bacillus caldoxyloyticus. On the basis of biochemical and physiological properties and phylogenetic analysis, we named the isolated strain as Bacillus sp. JE 375. The thermostable protease from Bacillus sp. JE 375 had been partially purified and characterized. The molecular weight of the enzyme was deduced from SDS-PAGE and gel chromatography as 55 kDa and its optimal temperature was $60^{\circ}C$. The enzyme showed its highest activity at pH 7.5 and was stable from pH 7.0 to 8.0.

• Microbiology and Biotechnology Letters
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• v.16 no.2
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• pp.126-130
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• 1988

Promoters of an alkali-tolerant Bacillus sp. isolated from soil have been cloned in Bacillus subtilis using promoter probe vector pPL703. The CAT specific activity of a clone harboring the strongest promoter activity among these transformants was 8.01. This activity was 2.5 times higher than that of Bacillus subtilis harboring expression vector pPL708 and was increased after the end of the logarithmic growth phase. In the 2.8kb of inserted DNA fragment, BamHI and Sal I recognition sites were located.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.386-389
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• 2002

Antagonistic Bacillus sp. #16 to phytopathogenic fungi were selected based on the growth rate, inhibition rate and surface tension reduction. Based on the 16S rRNA sequences, Bacillus sp. #16 is closely related to the B. subtilis DSM10. In the pot test, Bacillus sp. #16 show the most effective growth inhibition against damping-off disease of cucumber seeding.

• Microbiology and Biotechnology Letters
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• v.30 no.2
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• pp.123-128
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• 2002

A bacterium producing the extracellular xylanase was isolated from soil and has been identified as a Bacillus sp. strain. The isolate, named Bacillus sp. AMX-4, was shown to be similar to B. subtilis strain on the basis of its chemical compositions. The xylanase of culture supernatant was most active at 50℃ and pH 6.0. The additional carbon sources including monosaccharides, disaccharides, wheat bran, and rice straw increased the enzyme productivity. Especially, the maximum xylanase productivity was reached 29.2 units/ml in LB medium supplemented with 1.5％ (w/v) xylose, which was 16-folds more than that in LB medium. As the results of investigating the effects of xylose on cell growth and xylanase productivity of Bacillus sp. AMX-4, increase of xylanase production was owing to the induction of xylanase biosynthesis. It was also found that the enzyme production was in association with the growth of Bacillus sp. AMX-4.

• Journal of Life Science
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• v.22 no.5
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• pp.605-612
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• 2012

Spore-forming bacteria are being used as probiotic supplements for human and animal use, due to their low pH stability and ability to survive the gastric barrier. In this study, the BCNU 9028 strain was screened from meju, a Korean fermented soybean food starter. Biochemical and physiological characteristics, as well as 16S rDNA sequence analyses, indicate that this strain belongs to the genus $Bacillus$. $Bacillus$ sp. BCNU 9028 showed a 92% survivability at pH 2.5 and could also withstand 0.3% ox bile. Furthermore, it was postulated that $Bacillus$ sp. BCNU 9028 could prevent biofilm formation and adherence of food-borne pathogens such as $Listeria$ $monocytogenes$, $S.$ $aureus$ and $E.$ $coli$ on the basis of its autoaggregation and coaggregation capacity with food-borne pathogens. It was shown that BCNU 9028 has good abilities to adhere to the intestinal tract from its hydrophobic character (63.3%). The $Bacillus$ sp. BCNU 9028 strain especially elicited antibacterial activity against both Gram-positive and -negative pathogens. These findings suggested that the $Bacillus$ sp. BCNU 9028 strain could be used as a potential probiotic.

• Microbiology and Biotechnology Letters
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• v.16 no.4
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• pp.316-319
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• 1988

Pectate Lyase (PL) was cloned from alkali-tolerant Bacillus sp. YA-14 into Escherichia coli MB1000 by inserting HindIII-generated DNA fragment into the HindIII site of pBR322 and then screening recombinant transformant for the ability to hydrolyze sodium polypectate on agar plate, The recombinant plasmid, called pYPC29, was isolated, and the size of the cloned HindIII fragment was found to be 1.6 kb. The PL gene was stablely maintained and expressed efficiently in Escherichia coli. The Pt accumulated largely in the periplasmic space of Escherichia coli clones.