• Proceedings of the Korean Society of Life Science Conference
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• 2001.02a
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• pp.65-65
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• 2001

• Journal of Life Science
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• v.23 no.2
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• pp.273-281
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• 2013

The purpose of this research was to investigate the production and characterization of alkaline protease from Micrococcus sp. PS-1 newly isolated from seawater. Micrococcus sp. PS-1 was grown in Luria-Bertani (LB) medium. Its optimal temperature and pH for growth were $30^{\circ}C$ and 7.0, respectively. The effect of nitrogen sources was investigated on optimal enzyme production. A high level of alkaline protease production occurred in LB broth containing 2% skimmed milk. The protease was purified in a 3-step procedure involving ultrafiltration, acetone precipitation, and dialysis. The procedure yielded a 16.43-purification fold, with a yield of 54.25%. SDS-PAGE showed that the enzyme had molecular weights of 35.0 and 37.5 kDa. Its maximum protease activity was exhibited at pH 9.0 and $37^{\circ}C$, and its activity was stable at pH 8.0-11.0 and $25-37^{\circ}C$. The protease activity was strongly inhibited by PMSF, EDTA, and EGTA. Taken together, the results demonstrate that the protease enzyme from Micrococcus sp. PS-1 probably belongs to a subclass of alkaline metallo-serine proteases.

• Journal of Environmental Science International
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• v.6 no.2
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• pp.153-163
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• 1997

In order to fad the most fitted biodegradation model, biodegradation kinetics model to the initial phenol and p-cresot concentrations were investigated and had been fitted by the linear regression. Bacteria capable of degrading p-cresol were isolated from soil by enrichment culture technique. Among them, strain Ml capable of degradillg p.rcresol has also degraded phenal and was identified as the genus Micrococcus from the results from of taxonomical studies. The optimal tonditlons for the biodegradation of phenal and p-cresol by Micrococcus sp. Ml were $NH_4NO_3$ 0.05%, pH 7.0, 3$0^{\circ}C$, respectively, and medium volume 100m1/250m1 shaking flask. iwicrococcus sp. Ml was able to grow on phenal concentration up to 14mM and p-cresol concelltration up to 0.8mM. With increasing substrate concentraction, the lag period increased, but the maximum specific growth rates decreased. The yield coefficient decreased with increasing substrate concentation. The biodegradation kinetics of phenol and p-cresol were best described by Monod with growth model for every experimented concentration. In cultivation of mixed substrate, p-cresol was degraded first and phenol was second. This result implies that p-cresol and phenol was not degraded simultaneously.

• Applied Biological Chemistry
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• v.34 no.4
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• pp.327-333
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• 1991

This study was carried out to determine the effects of media compositions on cell growth and casein hydrolysis for cell production in order to add Micrococcus sp. LL3 as a potential agent for industrial application for the shortening of ripening period. Monosaccharides like glucose, mannose and fructose were mare excellent as carbon source, but arabinose and xylose markedly inhibited cell growth and caseinolysis. Among the organic nutrients, yeast extract was more effective for cell growth and for caseolysis. However, inorganic nitrogen sources were less effective than organic sources. Urea inhibited cell growth severely. Cell growth and caseinolysis were rather increased a little in the broth containing 1% NaCl, and the organism tolerated and grew in relatively high concentrations of NaCl up to 9%. Addition of vitamin did not affect cell growth and caseolysis in level of $0.1\;{\mu}g/ml$ concentration. Cell growth and caseinolysis were stimulated by addition of glutamic acid and $MgSO_4$ with concentration of 0.2% and 0.05% respectively.

• Korean Journal of Agricultural Science
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• v.21 no.1
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• pp.11-21
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• 1994

The halophile, Micrococcus sp. which produces RNase was isolated from salted and fermented food. The optimum growth condition of the Micrococcus sp. in pH 7.0 of complex medium containing 2M NaCl, and at $35^{\circ}C$. Optimum condition for enzyme production by this strain was when it was grown in the CM medium, containing 2% yeast extract, 1.5% casamino acid and 2M NaCl in the initial pH 8.5 for 2 days. The maximal RNase activity was observed at pH 8.0 and $55^{\circ}C$. The Km value for RNA was determined to be 5mg/ml by Lineweaver-Burk plot. The RNase activity in the absence of NaCl was maximum, but it was completely lost by adding of 1.25M NaCl and it was increased above 1.25M to 2.5M NaCl. When 2.5M NaCl was added, the activity of RNase showed 45% of maximum value.

• Journal of Microbiology and Biotechnology
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• v.5 no.1
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• pp.1-5
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• 1995

A genomic DNA of alkaliphilic bacterium, Micrococcus sp. Y-l, was analysed using the physical mapping method of pulsed-field gel electrophoresis (PFGE). Five restriction enzymes of Sspl, Hpal, Xbal, Ndel or EcoRI, which recognize the Adenine-Thymine-rich sequences of genomic DNA, were used for the generation of few (7 to 20) distinctly separate fragments, with average sizes in the range of 200～500 kb. However, the sites for Notl and SfiI, 8 base-recognizing enzymes, were highly frequent. The genome size of this strain was determined to be 4 mega base pairs (Mb) from restriction fragments separated by PFGE. This is the first case of restriction mapping in alkaliphilic bacterium.

• Preventive Nutrition and Food Science
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• v.7 no.1
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• pp.33-36
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• 2002

A catalase from Micrococcus sp. isolated from soil was applied to degrade hydrogen Peroxide in wastewater from a semiconductor industry. The degradation rates of hydrogen peroxide increased with increasing reaction time and catalase concentrations in the reaction mixture. However, in the presence of aluminum chloride or chloride oxide used in detergent compounds, the degradation rate of hydrogen peroxide was not affected. Enzyme stabilizers and antifoam did not affect the degradation rates of hydrogen peroxide.

• Korean Journal of Microbiology
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• v.24 no.3
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• pp.329-334
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• 1986

The bacteria capable of utilizing polyethylene glycol(PEG) 6,000 as a sole carbon source were isolated from soil and sewage water connected to factory area. The isolate designated as EL-033 had high biodegradability on PEG 6,000, and was identified as Micrococcus sp. Micrococcus sp. EL-033 could grow on and degrade di-, tri-, tetraethylene glycols and PEGs with molecular weight up to 6,000 and very slowly stilize PEG 20,000 as sole carbon source, but not degrade ethylene glycol. The growth rate of isolate was increased in the higher molecular weight PEGs. The optical culture medium was established to be as follow: PEG 6,000, 0.2%(w/v); $K_2HPO_4$, 0.1%; $NaH_2PO_4{\cdot}12H_2O,\;0.1%\;:\;MgSO_4{\cdot}7H_2O$, 0.05%; polypeptone, 0.1% in distilled water, pH7.5. About 90% of PEG 6,000 was degraded in exponential phase of 48h culture and PEG 6,000 was completely degraded during 72h.

• Applied Biological Chemistry
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• v.36 no.6
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• pp.539-546
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• 1993

This paper describes the purification and partial characteristics of aminopeptidase from Microccus sp. LL3 to utilize the microorganism as a potential agent for industrial application for the purpose of shortening ripening period of cheddar cheese. The optimal temperature and pH for enzyme activity were $35^{\circ}C$ and 7.0, respectively for L-leucine-p-nitroanilide as substrate. The enzyme remained stable for 10 minutes up to $50^{\circ}C$. The activity of aminopeptidase was stimulated by $Mg^{++}$ ion but strongly inhibited by $Hg^{++}$, metal complexing reagents, ethylenediaminetetraacetate (EDTA) and 1,10-phenanthroline. The enzyme was thought to be metallopeptidase. This enzyme had a broad substrate specificity, but was inactive on peptide with arginine as N-terminal amino acid. An intracellular aminopeptidase from Micrococcu sp. LL3 was purified by chromatography on DEAE-Sephacel and filtration on Sepacryl S-300. The enzyme has a molecular weight of 43,500.

• Journal of Food Hygiene and Safety
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• v.31 no.3
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• pp.201-209
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• 2016

Many atmospheric pollutants including chemical agents, house dust, and microorganisms cause building-related illnesses through respiration in humans. This study was conducted to analyze the profiles of microbial pollutants in air purifiers used in home, office and playschool. Dominant eleven species of microorganisms were isolated and identified in environmental air and air purifiers. Among them, Staphylococcus sp., Micrococcus sp. and Bacillus sp. are the most dominant species. By phylogenetic analysis of the 16S rRNA gene, the dominant bacteria were identified as Staphylococcus epidermidis, Micrococcus luteus and Bacillus epidermidis, respectively. It has been known that these bacterial species are closely related with food spoilage and human infectious disease. Thus, these results indicate that microbial pathogens related with human illnesses through respiration will be contaminated in air purifiers and also need to develop a method to control those of pathogens for human health.