• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2002.10a
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• pp.101-101
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• 2002

• Archives of Pharmacal Research
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• v.13 no.1
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• pp.33-37
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• 1990

The effects of pH values, temperature and some elements on the amylolytic activity and stability of the purified S. aureofacienc 77 amylase were studied in this investigation. The purified enzyme showed its maximum activity at pH 6 within 8 min incubation at $40^{\circ}C$. None of the tested 6 metals showed on stimulatory effect on the enzymatic activity, $Fe^{+++}$, $Cu^{++}$ and $Hg^{++}$ at high dose inhibited the enzyme activity to great extent as compared with $Zn^{++}$, $Mn^{++}$ and $Fe^{++}$ whih gave less effect in this respect. The enzyme liquor was found to be thermolabile, since it lost completely its activity after 4 days incubation under room temperature and showed maximum activity during this period as a result of additions of $Ca^{++}$and NaCl, Gradual reduction was however recorded until activity reached 30% after 60 days of incubation.

• Journal of Microbiology
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• v.37 no.3
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• pp.159-167
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• 1999

The effects of bicarbonate concentration, atmospheric carbon dioxide level, and reduced atmospheric oxygen on biomass and geosmin production and geosmin/biomass (G/B) values for Streptomyces halstedii, a producer of the off-flavor compound geosmin, were determined. In addition, a study was performed to determined possible synergistic relationships between a cyanobacterium, Oscillatoria tenuis UTEX #1566, and S. halstedii in the enhancement of actinomycete growth and/or geosmin production. These studies took into consideration those conditions that can occur during cyanobacterial bloom die-offs. Increasing bicarbonate concentration caused slight decreases in geosmin production and G/B for S. halstedii. Increasing atmospheric oxygen promoted geosmin production and G/B while lower oxygen levels resulted in a decrease in geosmin production and G/B by S. halstedii. Biomass production by S. halstedii was adversely affected by reduced oxygen levels while changes in bicarbonate concentration and atmospheric carbon dioxdie levels had little effect on biomass production. Sonicated cells of O. tenuis UTEX #1566 promoted biomass production by S. halstedii, and O. tenuis culture (cells and extracellular metabolites) and culture supernatnat (extracellular metabolites) each promoted geosmin and G/B yields for S. halstedii. In certain aquatic systems, environmental conditions resulting from cyanobacterial blooms and subsequent bloom die-offs could favor actinomycete growth and off-flavor compound by certain actinomycetes.

• Journal of Life Science
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• v.28 no.12
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• pp.1477-1488
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• 2018

This study investigated the muscles, intestines, and gonads of Sulculus diversicolor supertexta to examine the diversity of microbial communities within examples collected from the Jeju Coast. Using different media, initial pure isolation in MA, 1% BHIA, and 1% TSA indicated that the muscles, intestines, and gonads supported more communities, respectively. In analysis of relative similarity with 16s rRNA sequencing, 190 pure colonies were isolated, and further analysis with NBLAST identified 71 species, 39 genera, 25 families, and five phyla. Homogeny with the reference strain was 91-100%. Microbial communities in S. supertexta consisted of gamma and alpha Proteobacteria (48%), Actinobacteria (32.5%), Firmicutes (16.9%), Deinococcus-Thermus (1.3%), and Bacteroides (1.3%). In all tissue, Psychrobacter cibarius in Moraxellaceae was dominant. Alteromonadaceae, Enterobacteriaceae, Pasturellaceae, Moraxellaceae, Rhodobacteraceae, Geminicoccaceae, Dietziaceae, Intrasporangiaceae, Microbacteriaceae, Micrococcaceae, Micromonosporaceae, Streptomycetaceae, Aerococcaceae, Bacillaceae, Paenibacillaceae, Planococcaceae, and Staphylcoccaceae were commonly isolated across all tissues, and Flavobacteriaceae, Corynebacteriaceae, Yesiniaceae, Vibrionaceae, Hahellaceae, Pseudomonadaceae were also identified from the intestines. In microbial monitoring of four harmful bacteria, Streptomyces albus (96%) showed antibacterial activity against all four strains, and Agrococcus baldri (99%) and Psychrobacter nivimaris (99%) presented against E. Coli and E. aerogens. In addition, some strains with low homogeny were isolated and further experiments are therefore required, for example to refine the antimicrobial substances including new strain investigations. These additional experiments would aim to establish generic resources for the microbial communities in S. Supertexta and provide basic data for applied microbiological research.