• Microbiology and Biotechnology Letters
• /
• v.23 no.1
• /
• pp.36-42
• /
• 1995

Actinomycetes occur in a wide range of environments and many more actinomycetes remain to be detected in the natural environment. In isolation stages, selection of the environment as a source of useful isolates is important. Two hundred and eighteen strains were isolated on Bennet's agar and 346 strains were on humic acid-vitamin agar from five each paddy field, field, forest, grass land, riverside soil samples. These isolates were identified to the genus level based on morphological and physiological characteristics. Among them, 386 strains were Streptomyces, 49 strain were Nocardia, 35 strains were Microbispora and Micromonospora each, 15 strains were Nocardiopsis, 13 strains were Actinomadura, 10 strains were Streptosporangium, and the others were isolated rarely. According to soil type, Nocardia, Micromonospora, Microbispora and Streptosporangium were dominant in paddy field, Microbispora Nocardia, Nocardioides and Micromonospora were dominant in field, Nocardia, Micromonospora, Microbispora and Actinomadura were dominant in grass land, Nocardia, Micromonospora and Microbispora were dominant in forest, Nocardia, Microbispora and Micromonospora were dominant in riverside. Generally, Nocardia, Micromonospora, Microbispora and Actinomadura were isolated in all kinds of soils, Streptosporangium were paddy field, Dactylosporangium were forest, Nocardiopsis were field, forest and riverside.

• Korean Journal of Microbiology
• /
• v.38 no.2
• /
• pp.139-143
• /
• 2002

To find $\alpha$-glucosidase inhibitors produced by Actinomycetes, bacteria belonging to Actinomycetes were isolated from soil sample using Bennett's medium. The inhibitory activity induced by these bacteria on $\alpha$-glucosidase, which is the key enzymes far carbohydrates digestion and the prevention of diabetic complications, was investigated. A strain of these bacteria, PM718 potently inhibited $\alpha$-glucosidase activity in vitro.

• YAKHAK HOEJI
• /
• v.35 no.3
• /
• pp.245-251
• /
• 1991

Selective culture of actinomycetes from soil microbes and their antibiotic producing characters by agar-disk method were examined. Some of the organisms which produced antibiotics on agar disk did not produce antibiotics in liquid culture. Further examination indicated that production of antibiotic was dependent on the composition of medium. Many streptomycestes produced antibacterial substances in tryptic soy broth but others produced antifungal antibiotics in V-8 broth. Production of antibacterial substances by Streptomyces sp. was also dependent on the medium composition.

• Korean Journal of Environmental Biology
• /
• v.24 no.1 s.61
• /
• pp.38-45
• /
• 2006

Ecological characteristics of microbial populations inhabiting heavy metal polluted soil were investigated. The samples were collected from 293 sites around an factory and industry at Gyeoungsangbuk-do. We measured the contents of seven heavy metal elements (Cd, Cu, As, Hg, Pb, $Cr^{6+}$, CN), seven sites have been seriously contaminated by mercury and chrome. A quantitative evaluation of microbial populations in mercury and chrome contaminated soil was examined by using plate count method. Bacterial numbers in polluted soil samples ranged from $7.4X10^5\;to\;9.3X10^7\;cfu\;g^{-1}$, about $10\sim100$ fold less than the count for the unpolluted soil. Moulds were not detected in chrome polluted soil. The log values of actinomycetes of each contaminated soil samples were log ranged from 6.18 to 7.52. The ratio of actinomycetes was similar to unpolluted soil. The investigation showed actinomycetes to be the major microbial population inhabiting the mercury and chrome polluted soil. Thirty-one isolates among the total isolates were examined for antibacterial activity. These isolates were identified based on a phylogenetic analysis using 16S rRNA gene nucleotide sequences, they were categorized in three major phylogenetic groups, belong to the Streptomyces (6 strains), Saccharopolyspora (3 strains), Nocardiodes (1 strain). On the phylogenetic tree, the clade consisting of five isolates were distantly related to all of the established Streptomycetes genera, indicating the possibility as members of new species.

• YAKHAK HOEJI
• /
• v.32 no.5
• /
• pp.304-307
• /
• 1988

394 strains of soil microorganism were isolated from the Korean soil samples. The isolated strains were shake-cultured in oat-meal medium. The filtrates of the cultures were screened for the production of ${\alpha}-amylase$ inhibitors. Five strains were identified to produce ${\alpha}-amylase$ inhibitors. And these strains were identified as Actinomycetes.

• Proceedings of the PSK Conference
• /
• 2002.10a
• /
• pp.331.1-331.1
• /
• 2002

Actinomycetes CS0703 has been isolated in soil sample from location in the Jeju province. Korea. and produces alkaline extracellular proteases. To maximize protease production, initial pH of the culture medium was adjusted to 12.0 with NaOH and incubated at $48^{\circ}C$ on a rotary shaking incubator(180rpm). Actinomycetes CS0703 produced high level of protease at late exponential phase when grown in OSYM medium (oatmeal 2.0%. soybean meal 1%. dried yeast 1%. mannitol 1%). (omitted)

• Microbiology and Biotechnology Letters
• /
• v.27 no.6
• /
• pp.515-517
• /
• 1999

From the soils collected seasonally at the 0.5~2cm and 50$\pm$1cm depths of riverside, different strains of actinomycetes were isolated and identified to the genus. At the 0.5~2cm depth, Streptomyces and rare actinomycetes were in total 73 and 62 strains, respectively. Streptomyces was approximately 2-fold more in spring and autumn than summer, and rare actinomycetes was at least 4-fold more in autumn and winter than spring. At the 50$\pm$1cm depth, Streptomyces and rare actinomycetes were in total isolated 53 and 41 strains, and these were at least 2-fold more diverse in autumn than spring, summer, and winter.

• Microbiology and Biotechnology Letters
• /
• v.17 no.2
• /
• pp.121-125
• /
• 1989

Actinomycetes GF 155-2, which produced an extracellular pepsin inhibitor, was isolated from soil samples. Optimal conditions of inhibitor production by flask-shacking culture were 2% glucose, 0.7% polypeptone, initial pH 1.0, culture time 60 hours and temperature 30%. Effect of in-organic salts was not observed. About 5mg of colorless crystalline inhibitor was obtained from 5L culture broth in jar tormentor by means of ammonium sulfate precipitation, methanol extraction, and column chromatographies on Amberlite IR-120, XAD-2 and silicagel 60.

• Microbiology and Biotechnology Letters
• /
• v.25 no.6
• /
• pp.537-545
• /
• 1997

The aim of the present research program was to isolate a strain of actinomycetes producing antifungal substance. Soil samples were collected from various sites in Korea and a number of actinomycetes were isolated from the soil samples by applying selective agar for actinomycetes. Among isolates, a strain (NA -52) producing antifungal substance against Pyricularia oryzae was selected. Chemotaxonomic and numerical identification were carried out for the isolate. Fifty taxonomic unit characters were tested and the data were analyzed numerically using TAXON program. The isolate was identified as a synonym of streptomyces diastaticus belong to cluster No. 19 (Streptomyces diastaticus). But it showed a low similarity to S. diastaticus in simple matching coefficients, hence it was considered as one new species in Streptomyces.

• Microbiology and Biotechnology Letters
• /
• v.24 no.6
• /
• pp.664-670
• /
• 1996

The aim of the present research program was to develop a strain of actinomycetes producing antifungal substance. Soil samples were collected from various sites in Korea and a number of actinomycetes were isolated from the soil samples by applying selective agar for actinomycetes. Among over 440 isolates, a strain (NA-4803) producing antifungal substance against Trichophyton spp. Nannizzia otae and Pyricularia oryzae was selected. The strain NA-4803 was identified as strain similar to Streptoverticillium blastmyceticum with respect to morphological and physiological characteristics, lecithinase and lipolytic activity, degradation of organic compounds, resistance to antibiotics and utilization of carbon and nitrogen sources. But it showed some differences such as positive reaction of nitrate reduction, negative reaction of L-tyrosine degradation, resistance to cephaloridine, and utilization of I -rhamnose and inulin. The strain NA-4803 was named as Streptoverticillium sp. NA-4803.