• Korean Journal of Microbiology
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• v.39 no.3
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• pp.187-191
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• 2003

In an attempt to isolate myxobacteria from soil samples, we isolated swarm and fruiting body forming bacteria that have bacteriolytic activity on Coli-spot agar plate. For the classification of myxobacteria, 16S rDNA RFLP patterns were analyzed. Amplified 16S rDNAs of myxobacteria type strains (Family I, II, III and IV), negative control strains and soil-isolates were restricted with HaeIII, EcoRI and EcoRV, respectively. We found that the soil-isolates belongs to myxobacteria Family I, II, III.

• Microbiology and Biotechnology Letters
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• v.31 no.1
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• pp.1-12
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• 2003

Myxobacteria are soil bacteria that move by gliding and have a complicated life cycle. In the research over the 25 years the myxobacteria have been shown to be a rich source of potentially useful bioactive substances. So far about 80 different basic compounds and 450 structural variants have been characterized. It is remarkable that myxobacteria produce the substance has special mechanisms. 26 new electron transport inhibitors,5 inhibitors of nucleic acid polymerases, 10 substances that act on the cytoskeleton, and 1 inhibitor of fungal acetyl-CoA carboxylase have been found. Presently, large-scale technical process was not fully established. But one of the compounds from myxobacteria is able to pass the many thresholds, which are on the road to application.

• Korean Journal of Microbiology
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• v.45 no.1
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• pp.48-53
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• 2009

591 strains of myxobacteria that grew on cellulose as a sole carbon source were isolated from soils collected from various locations in Korea. Morphological characteristics such as the shape of cells, colonies and fruiting bodies and 16S rRNA sequences of the isolates suggested that all the isolates are Sorangium cellulosum. An antifungal assay has indicated that at least 20 strains among the 114 isolates tested produce antifungal substances inhibiting growth of Candida albicans.

• Korean Journal of Microbiology
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• v.46 no.4
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• pp.405-408
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• 2010

Diversity of myxobacteria in five soil samples from Asansi and Uponeup in Korea was explored by means of polymerase chain reaction (PCR) using primers that specifically bind 16S rDNA of myxobacteria. DNA sequence analysis of 76 PCR fragments containing myxobacterial 16S rDNA revealed five putative novel myxobacterial genera whose 16S rDNA sequences shared <95% sequence identity with those of the type strains. This finding indicates the presence of many uncultured and unidentified myxobacterial species in Korean soil.

• Journal of Microbiology and Biotechnology
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• v.18 no.8
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• pp.1416-1422
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• 2008

Epothilone and its analogs are a potent new class of anticancer compounds produced by myxobacteria. Thus, in an effort to identify new myxobacterial strains producing epothilone and its analogs, cellulose-degrading myxobacteria were isolated from Korean soils, and 13 strains carrying epothilone biosynthetic gene homologs were screened using a polymerase chain reaction. A migration assay revealed that Sorangium cellulosum KYC3013, 3016, 3017, and 3018 all produced microtubule-stabilizing compounds, and an LC-MS/MS analysis showed that S. cellulosum KYC3013 synthesized epothilone A.

• Journal of Microbiology and Biotechnology
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• v.19 no.11
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• pp.1288-1294
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• 2009

We have used mutational analysis to identity four genes, MXAN3553, MXAN3554, MXAN3555, and MXAN3556, constituting an operon that is essential for normal fruiting body development in Myxococcus xanthus. Deletion of MXAN3553, which encoded a hypothetical protein, resulted in delayed fruiting body development. MXAN3554 was predicted to encode a metallopeptidase, and its deletion caused fruiting body formation to fail. Inactivation of MXAN3555, which encoded a putative NtrC-type response regulator, resulted in delayed aggregation and a severe reduction in sporulation. Fruiting bodies also failed to develop with the deletion of MXAN3556, another gene encoding a hypothetical protein.

• The Plant Pathology Journal
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• v.27 no.3
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• pp.257-265
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• 2011

During 2002-2008 in Korea, 455 extracts from myxobacteria consisting of 318 cellulolytic and 137 bacteriolytic myxobacteria were isolated, which were then screened for antifungal activity against the phytopathogens Botrytis cinerea, Colletotrichum acutatum, Penicillium sp., Pyricularia grisea, and Phytophthora capsici. 204 isolates had antifungal activity, causing both a clear zone due to blocked spore germination and inhibition of mycelial growth; most (199) were from cellulolytic (Sorangium cellulosum) and only five were from bacteriolytic myxobacteria. B. cinerea, the best controlled among the five tested pathogens, had a unique group of antifungal isolates of myxobacterial extracts compared to the other pathogens' groups. Among seventy-nine bioactive myxobacteria, four isolates, KYC 3130, KYC 3247, KYC 3248 and KYC 3270, were selected and all were cellulolytic. Liquid culture filtrates of these four myxobacteria were applied to tomato, cherry tomato, strawberry, and kiwi fruits 5 h before inoculation with gray mold conidia; then the treated fruits were placed in an airtight container and the experiment was repeated six to eight times. Incidence (%) of gray mold on fruit of the infected control treatment was 84-98%, whereas it was only 5-21% after the KYC 3270 treatment. After KYC 3270 treatment of the four fruits, mold control was 79-95%, which was highest among the filtrates and statistically the same as treatment with fludioxonil, a registered chemical against gray mold of stored fruits.

• Microbiology and Biotechnology Letters
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• v.39 no.1
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• pp.20-28
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• 2011

Phylogenetic analysis of two cellulase genes, xynB1 and bglA2, and the groEL1 gene from 34 Sorangium cellulosum strains isolated in Korea suggested that there are at least five subgroups in S. cellulosum, which is the most proficient producer of secondary metabolites among myxobacteria. This analysis also revealed diversity among the isolated S. cellulosum. It appeared that at least 30 out of 34 strains are different each other.

• Microbiology and Biotechnology Letters
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• v.49 no.1
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• pp.32-38
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• 2021

Tubulysins are a group of secondary metabolites produced by myxobacteria that inhibit the function of the eukayotic cytoskeleton. We developed a pair of PCR primers that specifically amplified tubulysin biosynthetic genes. Using these primers, eight out of the eighty-one strains of myxobacteria belonging to the Cystobacteraceae family that harbored putative tubulysin biosynthetic genes were screened through PCR analysis. The selected strains included two Archangium gephyra, two Stigmatella sp., two Vitiosangium cumulatum, and two unidentified myxobacteria. LC-MS analysis of the culture extracts from the selected strains revealed that A. gephyra KYC4066 produced putative tubulysin A and B.

• Microbiology and Biotechnology Letters
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• v.37 no.1
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• pp.10-16
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• 2009

Polymerase chain reactin (PCR) could be a simple way to screen new microbial strains producing useful secondary metabolites if their biosynthetic genes are known and candidate strains to be screened are available. In this study, we have screened two myxobacterial strains, KYC3047 and KYC3076, carrying genes appeared to be biosynthetic genes of soraphen A, a potent antifungal substance, out of 50 cellulose degrading myxobacteria using PCR. The two strains were identified as Sorangium cellulosum based on morphological, physiological, and molecular biological characteristics. Both of the strains produced substances having strong antifungal activities as expected against Candida albicans, a causative agent of candidiasis, and Colletotrichum acutatum, a causative agent of anthracnose on pepper.