• Title/Summary/Keyword: Microbial Acitivity

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Asparagine Residue at Position 71 is Responsible for Alkali-Tolerance of the Xylanase from Bacillus Pumilus A-30

  • Liu, Xiang-Mei;Qi, Meng;Lin, Jian-Aiang;Wu, Zhi-Hong;Qu, Yin-Bo
    • Journal of Microbiology and Biotechnology
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    • v.11 no.3
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    • pp.534-538
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    • 2001
  • The xynA gene encoding an alikali-tolerant endo-1,4-${\beta}$-xylanase (XYN) was cloned from the alkalophilic Bacillus pumilus A-30. The nucleotide sequence of a 974-bp DNA fragment containing the xynA was determined. An ORF of 684 nucleotides that encoded a protein of 228 amino aicds was detected. Asparagine-71 of XYN from B. Pumilus A-30 showed to be highly conservative in alkaline xylanases of family G/11, upon comparing the amino acid sequences of 17 family G/11 xylanases. Site-directed mutation of N71D of the xynA gene resulted in a decrease of 12.4% in the specific acitivity and a significant decline in the enzyme activity in the alkaline pH range.

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Effect of Microbial Activity by Using the Coagulants in the Biological Treatment Process (생물학적 처리공정에서 응집제 사용에 따른 미생물 활성도 영향)

  • Han, Seung-Woo;Chun, Mi-Hee;Park, Jun-Min;Kang, Dong-Hyo;Kang, Lim-Seok
    • Journal of Korean Society of Environmental Engineers
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    • v.34 no.1
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    • pp.16-22
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    • 2012
  • Alum contained dominantly the monomeric aluminum species, and PAC contained the polymeric aluminum species. Both Alum and PAC has been improved removal of TP with increasing coagulant dose. Coagulant used directly influenced the microbial activity. Impact on microbial activity, the PAC was smaller than Alum. And impact on microbial activity and population according to the return sludge appeared to be minor.

Microbial Aspartase and Its Activity on Deamination of L-Aspartyl-L-Phenylalanine Methyl Eester

  • Chang, Wonyoon;Goo, Yang-Mo
    • Archives of Pharmacal Research
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    • v.11 no.2
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    • pp.139-144
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    • 1988
  • Examination of many microorganisms and soil isolated for the activity of aspartase proved that R, rubra, G, suboxydans, A. versicolor, P. purpurogenum, E. coli, Ps. aeruginosa, A. gigantus, A, unguis, A. parasiticus and a soil isolate (S-90) had high activity of aspartase. Comparison of the activity of the aspartase by cell free extracts of these microorganisms with the activity of the enzyme catalyzing the deamination of aspartame by the same cell free extracts showed similar kinetic characteristics. The aspartase existing in the cell free extracts seemed to catalyze the deamination of aspartame, too.

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Antimicrobial Activity of Culture Filtrates from Pseudomonas aeruginosa KLP-2 Isolated from Cooling Tower-Water against Legionella pneumophila (냉각탑수에서 분리한 Pseudomonas aeruginosa KLP-2 배양여액의 Legionella Pneumophila에 대한 항균활성)

  • 박은희;차인호;이상준
    • Microbiology and Biotechnology Letters
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    • v.29 no.3
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    • pp.127-133
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    • 2001
  • Pseudomonas aeruginosa KLP-2 possessing antimicro- bial activity against Legionella pneumophila was isolated from cooling tower-waters. The culture filtrates of P. aeruginosa KLP-2 showed antimicrobial activity against L. pneumophila Vibro cholerae non-Ol. Bacillus cereus, Bacillus subtilis and staphylococcus aureus. The culture filtrates of P. aeruginosa KLP-2 showed the highest anti-microbial activity against. L pneumophila among micoorganisms tested in this study. The optimal conditions of temperature, pH carbon source and nitogen source to obtain maximal antimicrobial activity from culture filtrates of P. aeruginosa KLP-2 were determined to be 35$^{\circ}C$ pH 7.0 % of glycerol and 0.6% of proteose peptone respec- tively. The antimicrobial activity of culture filtrates from P. seruginosa KLP-2 was highest against L. pneumophila when cultivated with shaking for 24 h and without shaking for 4 day at 35$^{\circ}C$.

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Lactic Acid Fermentation of Dioscorea batatas and Its Anti-Inflammatory Effects on TNBS-induced Colits Model (TNBS에 의해 유도된 마우스 대장염모델에서 유산균 발효 마의 항염효과)

  • Hyun, Mee-Sun;Hur, Jung-Mu
    • Journal of Applied Biological Chemistry
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    • v.54 no.1
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    • pp.51-55
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    • 2011
  • To develop a health-aid preparation of Dioscorea batatas (DB), lactic acid fermentation was attempted using a mixed starter comprising of Lactobacillus acidophilus, Lactobacillus plantarum, Bifidobacterium longum. The anaerobic fermentation of a 10% DB flour suspension gave a uniform suspension of pH 3.65, containing $8{\times}10^6$ CFU/mL lactic acid bacteria. During the administration of the lactic acid fermented DB (FDB) and DB to trinitrobenzene sulfonic acid (TNBS)-induced colitis mouse model, histological lesions, morphological damage, and myeloperoxidase acitivity were significantly reduced at a dosage of 200 and 400 mg/kg/day. Dose-response (200 and 400 mg/kg/day) studies revealed that FDB pre-treatment of mice significantly ameliorated the appearance of diarrhoea and the disruption of colonic architecture. In FDB-pretreated mice, there was a significant reduction in the degree of both neutrophil infiltration (measured as decrease in myeloperoxidase activity) and weight loss rates. Theses findings suggest that FDB exerts beneficial effects in experimental colitis and may be useful in the treatment of inflammatory bowel disease.

Endochitosanase Produced by Bacillus sp. P2l as a Potential Source for the Production of Chitooligosaccharides. (키토산 올리고당의 제조용 소재로서 Bacillus sp. P2l 기원의 키토산분해효소)

  • 박노동;조유영;이현철;조종수;조도현
    • Microbiology and Biotechnology Letters
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    • v.26 no.4
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    • pp.345-351
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    • 1998
  • In an effort to develop a potent system for the production of various dp (degree of polymerization) chitooligosaccharides, 32 enzymes or microbial systems were screened for chitosanolytic acitivity using chitosan as a substrate. The efficiency of each enzyme system was evaluated by the changes of turbidity and viscosity of chitosan solution, the amount of precipitate and the reducing sugar-producing activity in the enzymatic reaction mixture. Based on these assay methods for the chitosanase activity, Bacillus sp. P2l out of 32 screened systems showed highly potent endochitosanase, which was comparable with a commercially available enzyme (E7). Chitooligosaccharides of dp 3-7 were separated by TLC as major enzymatic reaction products, suggesting that the chitosanase from Bacillus sp. P2l be endo-splitting type.

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Potential Effect of Solvent Fractions of Taraxacum mongolicum H. on Protection of Gastric Mucosa (민들레(Taraxacum mongolicum H.) 추출분획물이 위장보호에 미치는 효능 평가)

  • Han, So-Heui;Hwang, Jung-Keun;Park, Soo-Nam;Lee, Kil-Hong;Ko, Kang-Il;Kim, Ki-Su;Kim, Ki-Ho
    • Korean Journal of Food Science and Technology
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    • v.37 no.1
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    • pp.84-89
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    • 2005
  • Mongolian dandelion (Taraxacum mongolicum H.) extracted with solvents having different polarities were prepared to investigate protection activity of gastric mucosa. Ethanol extracts were successively reextracted with methylene chloride, and n-butanol. Concentrations of total flavonoids and luteolin in n-butanol extracts were 27.75 and 1.14%, respectively, much higher than those of other solvent extracts. Results of anti-microbial acitivity test against Helicobacter pylori and urease inhibition test revealed n-butanol extract exerted higher inhibition (13.16%) than other solvent extracts. Based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, n-butanol extract showed the highest efficiency of free radical-scavenger activity among the extracts ($SC_{50}\;47{\mu}g/mL$). Erythrocytic photohemolysis tests, for the protection of cell membrane showed that half-life of human erythrocytes was increased by the addition of n-butanol extract $({\tau}_{50}=172min;C=5.0{\mu}g/mL)$. These results indicate n-butanol extract of Mongolian dandelion may be useful as a adjuvant for gastric diseases.