• 한국생물공학회:학술대회논문집
• /
• 2005.04a
• /
• pp.420-422
• /
• 2005

TMC (Tautomycetin) is a liner polyketide immunosuppressive antifungal compound produced by Streptomyces spp. Inhibition of T cell proliferation with TMC was observed highly efficient at 100-fold lower than those needed to achieve maximal inhibition with cyclosporin A. To elucidate the biosynthetic pathway of TMC, a genomic DNA library was constructed using a E. coil-Streptomyces shuttle cosmid vector, pOJ446. The DNA libraries were screened by colony blot hybridization using several polyketide ${\beta}-ketosynthase$ (KS) probes amplified from TMC-producing Streptomyces genomic DNA using polymerase chain reaction (PCR), of which the degenerate primers were designed based on the highly conserved sequences present in KS domains of various type I polyketide synthase genes in Streptomyces species. This library construction and screening approach led to the isolation of several positive cosmid clones representing type I polyketide biosynthetic gene clusters. In addition, a Streptomyces regulatory gene called afsR2 (a global regulatory gene stimulating antibiotic production in both S. coelicolor and S. lividans) was successfully integrated into the TMC-producing Streptomyces chromosome via E. coil-Streptomyces heterologous conjugation mehtod. The more detailed results of production improvement and genetic characterization of TMC-producing Streptomyces spp. will be discussed.

• YAKHAK HOEJI
• /
• v.35 no.1
• /
• pp.30-37
• /
• 1991

Streptomyces actuosus DMCJ-49 and Streptomyces minoensis DMCJ-144 produce the .alpha.-amylase inhibitor. Inerspecific protoplast fusion technique was used to increase the productivity of .alpha.-amylase inhibitor. Four auxotrophic mutants were obtained respectively from two strains by N-methyl-N'-nitor-N-nitrosoguanidine(3mg/ml) treatment. The optimum conditions for the protoplast formation of Streptomyces actuosus DMCJ-49 ade was as follows; 1.2% w/v of glycine, 3mg/ml of lysozyme, and 30 min of lysozyme treatment followed by 36 hr. incubation in the protop-last formation medium. In case of DMCJ-144-his those were 1.2%w/v, 3 mg/ml, 30 minutes and 60 hours, respectively. Regeneration was accomplished with hypertonic soft agar medium that contained 0.4M sucrose, 20mM CaCl$_2$, 50 mM MgCl$_2$ and low levels of phosphate. Fusion of protoplasts carrying different auxotrophic markers was achieved by treatment with polyethylene glycol. The optimum concentration of polyethylene glycol 1450 for the production of recombinants was 40%w/v. When the protoplasts was treated with 40% polyethylene glycol for 30 minutes, the frequency of recombinants was 6.5$\times$$10^{-3}$ and the $\alpha$-amylase inhibition activity of $ade^-his^-$ No. 4, which is the fusant with the most improved activity increased from 33 to 125 I.U./ml.

• Korean Journal of Microbiology
• /
• v.43 no.2
• /
• pp.137-141
• /
• 2007

The similarities among five strains of Streptomyces were measured by the serological methods. Antigens were prepared by dissolving cell envelope fractions in Tween 20 buffer and antisera were produced from the immunized rabbits. Immunodiffusion studies and ELISA results showed that the degree of antigen-antibody reaction was not exactly matched to the taxonomic distance; i. e. the strains of the cluster group A exhibited low level of cross-reactions each other, while relatively strong cross-reactions were observed between Streptomyces lavendulae of cluster group F and Streptomyces viridochromogenes of cluster group A.

• Korean Journal of Microbiology
• /
• v.46 no.4
• /
• pp.359-365
• /
• 2010

Fifty Actinobacteria strains were isolated from rhizosphere soil of Sasa borealis. In the course of screening for antibacterial activity against bacterial leaf spot of pepper (Xanthomonas axonopodis pv. vesicatoria) of isolates, 12 isolates showed strong antibiotic activity. Basis on the 16S rRNA gene sequence, they were belonging to Streptomyces cluster II. Strain JR-24 exhibited strong antibiotic activity against X. axonopodis pv. vesicatoria, had a minimum inhibitory concentration of 10 ${\mu}l$/disc. The strain JR-24 was most closely related to Streptomyces galbus $DSM40089^T$ (98.1%), Streptomyces longwoodensis $LMG20096^T$ (98%) and Streptomyces capoamus $JCM4734^T$ (97.8%). When assayed with the API 20NE and 50 CHE kit, it is positive for utilization of L-arabinose, D-fructose, D-glucose, D-galactose and hydrolysis of gelatin, protein, starch. The strains contained iso-$C_{14:0}$ (25.93%), iso-$C_{15:0}$ (10.13%), anteiso-$C_{15:0}$ (19.29%) and iso-$C_{16:0}$ (20.35%) as major fatty acids and MK-9 (H4), MK-9 (H6), and MK-9 (H8) as the isoprenoid quinone. Strain JR-24 was suggested new species of genus Streptomyces by nearest neighbors of genotypic relationships and phenotypic characterization. This study was important to microbial resources investigation for environment-friendly agriculture.

• Research in Plant Disease
• /
• v.29 no.2
• /
• pp.174-183
• /
• 2023

The limited effectiveness of current plant disease management treatments necessitates the development of new methods for controlling diseases using beneficial microbes. Demanding sustainable agriculture is increasingly highlighted as a biocontrol approach, particularly Streptomyces species known to produce a variety of antibiotic compounds and secondary metabolites. The Streptomyces globisporus SP6C4 strain and Streptomyces sp. S8 have been reported as potent antifungal agents and are gaining attention for improving crop growth in sustainable agriculture. In this study, we investigated the use of Streptomyces species formulations to enhance bacterial growth with nitrogen sources. Specifically, the addition of L-glutamic acid and L-cysteine resulted in earlier sporulation and bacterial growth in Streptomyces strains, respectively. This approach could expand the range of fermentation techniques in agriculture and be useful for controlling plant growth-promoting bacteria.

• Microbiology and Biotechnology Letters
• /
• v.21 no.4
• /
• pp.299-305
• /
• 1993

Numerical identification was carried out for an isolate of Streptomyces D2-5 producing a new restriction endonuclease Svi I. Fifty taxonomic unit characters were tested and the data were analyzed numerically using the TAXON program. The isolate was best matched to Streptomyces violochromogenes in the major cluster 18 of Streptomyces. Therefore, it was concluded that the isolate was identified to be a member of Streptomyces violochromogenes.

• Microbiology and Biotechnology Letters
• /
• v.18 no.1
• /
• pp.94-97
• /
• 1990

The restriction cleavage map of multi-copy recombinant plasmid, pJY502 (5.5 kb), carrying the thiostrepton resistance gene (tsr) was determined. Comparison of the restriction pattern with that of Streptomyces plasmids previously demonstrated that pJY502 was novel. The plasmid pJY502 had a broad host range in Streptomyces and contained single BgtII site for cloning purpose. Transformation frequency of pJY502 was $2.2 \times 10^5$ in S. lividans. E. coti-Streptomyces bifunctional plasmid, pJY504, was also constructed.

• Journal of Microbiology and Biotechnology
• /
• v.2 no.3
• /
• pp.220-225
• /
• 1992

Chemotaxonomic and numerical identification were carried out for an isolate of Streptomyces strain SMF13 producing thiol protease inhibitor. Fifty taxonomic unit characters were tested and the data were analyzed numerically using the TAXON program. The isolate SMF13 was identified to be a member of the cluster 5 of Streptomyces and best matched to Streptomyces omiyaensis which is a synonym of Streptomyces exfoliatus. Therefore. it was concluded that the isolate was identified to be a strain of Streptomyces exfoliatus.

• Microbiology and Biotechnology Letters
• /
• v.25 no.3
• /
• pp.253-257
• /
• 1997

The secE gene of Streptomyces lividans TK24 was cloned by the polymerase chain reaction method with synthetic oligonucleo- tide primers designed on the basis of the nucleotide sequences of Streptomyces coelicolor secE-nusG-rplK operon. The deduced amino acid sequences of the SecE were highly homologous to those of other known SecE protein, that is 36.8%, 30.4%, 80.0%, and 80.9%, similarity to E. coli, Bacillus subtilis, Streptomyces griseus, Streptomyces virginiae SecE, respectively and exactly same with Streptomyces coelicolor SecE. It means that in spite of evolutionary differences, the genes for protein translocation machinery are highly conserved in eubacteria. The gene organization of secE-nusG-rplK is also similar to that of E. coli, B. subtilis, and streptomycetes.

• Journal of the East Asian Society of Dietary Life
• /
• v.7 no.1
• /
• pp.35-39
• /
• 1997

Studies on the glucose isomerase produced by alkalophilic Streptomyces sp. B-2. Glucose Isomerase (E. C. 5.3.1.5) which reversibly catalyzes reaction between D-glucose and D-fructose was demonstrated in cell free extracts of alkalophilic Streptomyces sp. B-2 isolated form soil. The maximum enzyme activity was found at glucose concentration 4(g/$\ell$) , xylose concentration 6(g/$\ell$), magnesium ion 1.0(g/$\ell$), yeast extract concentration 2.0(g/$\ell$), peptone concentration 3(g/$\ell$).