• Microbiology and Biotechnology Letters
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• v.27 no.4
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• pp.273-277
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• 1999

From each sediments collected at Chudong(static) and Hoenam(streaming) site of Lake Daechung on May 18(before rainy season) and on August 24 in 1998(after rainy season), different strains of Actinomycetes were isolated and identified to genus level. For comparison, the genus diversity of Actinomycetes in control soils such as grass land around lake, lake shore, and shallow(5-10cm) lake was also investigated. In consequence, the isolation of Streptomyces from the sediments of Lake Daechung was the most copious(41 strains) at the streaming site before rainy season and the least(27 strains) at the static site before rainy season, which were 2.4- and 1.6-fold larger than the average(17 strains) of control soils, respectively. In addition, the isolation of rare Actinomycetes from the sediments of Lake Daechung was the most copious(23 strains) at the streaming site before rainy season and the least(12 strains) at the static site after rainy season, which were 3.2-and 1.6-fold larger than the average(17 strain) of controls, respectively. Therefore, it is considered that lake sediments exhibit higher diversity of Streptomycete as well as rare Actinomycetes than general soils, and thereby can be utilized as useful sources to isolate diverse Actinomycetes.

• Microbiology and Biotechnology Letters
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• v.21 no.1
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• pp.88-94
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• 1993

Actinomycetes are the most diverse group of bacteria. in variety. morphology. and life cycle. Especially. the variety of genus and species of Actinomycetes is so diverse among other microorganisms that about 50 genus of Actinomycetes have been reported until now. Among them. Streptomyces genus is the most plentiful and over 220 species have been reported. The number of the genus of Actinomycetes will be expected to be fixed to about 55 genus and 250 Streptomyces species in the year 2000 thereabouts. Morphological and physiological characters of Actinomycetes varies with culture condition. and therefore diverse life cycles are also possible. In this paper. life cycles of the representative Actinomycetes, Nocardia, Streptomyces. Kitasatosporia. GeodermatoPhi/us. and Sporichthya. according to the condition of nutrient in the media were reviewed.

• Microbiology and Biotechnology Letters
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• v.28 no.3
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• pp.129-133
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• 2000

Different actinomycete strains were isolated from natural lime caves of Ondal Chemongok Hwanseon and Yongyeon which are located at Kangwon or chungcheongbook province in Korea and were identified to the genus level. Soil sam-ples were collected at 6 sites inside and 2 sites outside of each natural lime cave, As the result the strains belonging to genus Streptomyces and rare actinomycetes were isolated at the average of 2.1 and 3.4 strains per g soil on inside cave whereas which were isolated at the 6.0 and 1.8 strains per g soil on outside cave. How-ever the generic distribution of Streptomyces and rare actinomycetes isolated from outside cave was quite dif-ferent from that of inside cave. It was shown that rare actinomycetes at natural lime caves is generally highly abundant than Streptomyces.

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

• Korean Journal of Microbiology
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• v.52 no.1
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• pp.59-64
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• 2016

In this study, a pyrosequencing was performed and analyzed to verify the phylogenetic diversity of actinomycetes in the bamboo (Sasa borealis) soil as a base study to obtain the genetic resources of actinomycetes. It was found that the rhizosphere soil had much various distribution in bacterial communities showing a diversity of 8.15 with 2,868 OTUs, while the litter layer showed a diversity of 7.55 with 2,588 OTUs. The bacterial community in the bamboo soil was composed of 35 phyla and the predominant phyla were Proteobacteria (51-60%), Bacteroidetes (16-20%), Acidobacteria (4-16%) and Actinobacteria (4-14%). In particular, Actinobacteria including Micromonosporaceae and Streptomycetaceae had a diverse distribution of actinomycetes within the six orders, 35 families and 121 genera, and it was characterized that about 83% of actinomycetes within Actinomycetales belonged to the 28 families. Among the dominant actinobacterial populations, Micromonosporaceae, Pseudonocardiaceae and Streptomycetaceae were representative family groups in the bamboo soils.

• Korean Journal of Microbiology
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• v.49 no.2
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• pp.156-164
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• 2013

Actinomycetes produce diverse secondary metabolites which have the primary importance in medicine, agriculture and food production, and key to this is their ability to interact with other organisms in natural habitats. In this study, we have investigated the taxonomical and functional diversity of actinomycetes in fecal sample of rhinoceros beetle larvae (Allomyrina dichotoma L.) by using culture-dependent and -independent approaches. For the culture-independent approach, the community DNA was extracted from the sample and 16S rRNA genes of actinomycetes were amplified using actinomycetes-specific PCR primers. Thirty-seven clones were classified into 15 genera and 24 species of actinomycetes. For the culture-dependent approach, 53 strains were isolated from larval feces, of which 27 isolates were selected based on morphological characteristics. The isolates were classified into 4 genera and 14 species, and 24 isolates (89%) were identified as the genus Streptomyces. Many of the representative isolates had antimicrobial activities against plant pathogenic fungi and Gram-positive bacteria. In addition, most of the isolates (78%) showed biochemical properties to hydrolyze cellulose and casein. The results demonstrated that diverse and valuable actinomycetes could be isolated from insect fecal samples, indicating that insect guts can be rich sources for novel bioactive compounds.

• Journal of Environmental Science International
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• v.14 no.4
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• pp.367-371
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• 2005

Soil samples were collected from new-developed wetland soil ecosystem of Tamarix chinesis plantation in Chinese Yellow River Delta in different months of 2003. Soil characteristics, temporal change and spatial distribution of microbial community composition and their relationship with nitrogen turnover and circling were investigated in order to analyze and characterize the role of microbial diversity and functioning in the specific soil ecosystem. The result showed that the total population of microbial community in the studied soil was considerably low, compared with common natural ecosystem. The amount of microorganism followed as the order: bacteria> actinomycetes>fungi. Amount of actinomycetes were higher by far than that of fungi. Microbial population remarkably varied in different months. Microbial population of three species in top horizon was corrected to that in deep horizon. Obvious rhizosphere effect was observed and microbial population was significantly higher in rhizosphere than other soils due to vegetation growth, root exudation, and cumulative dead fine roots. Our results demonstrate that microbial diversity is low, while is dominated by specific community in the wetland ecosystem of Tamarix chinesi.

• Microbiology and Biotechnology Letters
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• v.30 no.1
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• pp.79-85
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• 2002

Ecological characteristics of microorganisms in tideland soils were studied by investigation of microbial diversity and population. Twenty soil samples were taken at surface, 10, 20 and 30 cm depth each. Bacteria, actinomycetes and fungi were isolated on each selective isolation medium containing different concentration of NaCl. Actinomycetes were the most isolated from soil samples taken at 10 cm depth and isolated by humic acid-vitamin (HV) medium without sea water or salt. Twenty nine strains of actinomycetes were isolated at surface soil and 74, 39, 37 strains were at 10, 20, and 30 cm depth, respectively. All these isolates were analysed and grouped by random amplified polymorphic DNA (RAPD)-PCR analysis. Many of the isolates were clustered into Microtetraspora and Pseudonocardia. Fungal isolates were highly distributed at the surface soil and isolated well on potato dextrose agar (PDA) medium with sea water. Bacterial isolates were higly distributed at surface soil and isolated well by nutrient medium without sea water or salt. Soil samples taken at 10 cm depth showed the highest microbial diversity and population.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.371-378
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• 2013

Various microorganisms live in soil, of which those colonizing rhizosphere interact with nearby plants and tend to develop unique microbial communities. In this study, we isolated diverse actinomycetes from rhizosphere of rice (Oryza sativa L.) cultivated in fertilized (APK) and non-fertilized (NF) paddy soils, and investigated the diversity and antimicrobial activity of them. Using four kinds of selective media, 152 isolates were obtained from the soil samples and identified by determining 16S rRNA gene sequence. All of the isolates showed 99.0%~100.0% similarities with type strains and were classified into six genera: Dactylosporangium, Micromonospora, Kitasatospora, Promicromonospora, Streptomyces and Streptosporangium. Most of the isolates, 143 isolates, were classified into the genus Streptomyces. Additionally, many isolates had antimicrobial activity against plant pathogens, especially Magnaporthe oryzae (rice blast pathogen) in fungi. These findings demonstrated that rice rhizosphere can be a rich source of antagonistic actinomycetes producing diverse bioactive compounds.

• Korean Journal of Microbiology
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• v.34 no.3
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• pp.149-153
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• 1998

From soils seasonally collected at two depths (0~2 cm, $50{\pm}1cm$) of forest, field, grass land, or paddy field, distinct strains of actinomycetes were isolated and identified to the genus level. The genus-diversity of soil actinomycetes was revealed to be considerably different by seasonal change. It was also affected by soil depths, soil types, or actinomycete groups. At the soil depth of 0~2 cm, the seasonal distribution fluctuation (%) of streptomycete strains was higher in grass land (41%), field (39%) soil than paddy field (18%), or forest (18%), whereas that of streptomycete strains at the soil depth of $50{\pm}1cm$ was high in order of paddy field (36%), field (28%), grass land (26%), and forest (16%). On the other hand, the seasonal distribution fluctuation ratio of rare actinomycete strains at the soil depth of 0~2 cm was above 45% except for paddy field (26%). At the soil depth of $50{\pm}1cm$, the seasonal distribution of rare actinomycete strains exhibited high fluctuation (%) in order of forest (79%), paddy field (36%), field (24%), and grass land (10%).