• 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/$\ell$).

• Journal of the East Asian Society of Dietary Life
• /
• v.10 no.5
• /
• pp.439-444
• /
• 2000

호알칼리성 방선균 Streptomyes sp. B-2를 Glucose Isomerse 생성을 위해 토양에서 분리했다. Glucose Isomerase(G.I)는 high fructose glucose syrup과 fructose의 생산을 위해서 식품 공업에서 아주 중요시되고 있는 효소이다. 호알칼리성 방선균 Streptomyces sp. B-2가 생성하는 glucose isomerase(G.I.)를 정제하였다. G.I.는 (NH$_4$)$_2$So$_4$분획, DEAE-cellulose, Sephadex G-200 chromatography하여 순수 분리 하였다. 순수분리된 G.I.는 electrophoresis에 의해 확인을 했다. SDS-acrylamide gel electrophoresis에 의해 정제된 효소는 single band를 보여주었다.

• The Korean Journal of Food And Nutrition
• /
• v.11 no.3
• /
• pp.319-322
• /
• 1998

The whole cell of alkalophilic Streptomyces sp. B-2 which produce glucose isomerase was immobilized by entrapment method for the effective production of high fructose syrup. The highest immobilized activity was achieved when the enzyme was bound to 2% $textsc{k}$-carrageenan. Immobilized glucose isomerase the pH optimum was about pH 7.5~8.5. Immobilization of alkalophilic Streptomyces sp. B-2 on 2% $textsc{k}$-carrageenan at 7$0^{\circ}C$ showed an increase in glucose isomerase activity. GI activity of immobilized cells was maximum Co2+ concentration 10-3M, Mg2+ concentration 10-3M.

• The Korean Journal of Pesticide Science
• /
• v.14 no.4
• /
• pp.326-331
• /
• 2010

Bacillus subtilis B29, B. subtilis M10 and Streptomyces sp. CC19 obtained from phyllosphere of cucumber plants were selected for biological control of fungal air-borne diseases. For the downy mildew, diseased area of B. subtilis B29, B. subtilis M10 and Streptomyces sp. CC19 showed 0.5%, 20.2% and 42.0%, but that of control was 82.0% respectively, in cucumber seedling test. Incidence of powdery mildew by once application of B. subtilis B29, B. subtilis M10 and Streptomyces sp. CC19 was 2.8%, 3.6% and 12.3%, respectively, whereas that of control was 65.6%. On the gray mold, diseased area of B. subtilis B29, B. subtilis M10 and Streptomyces sp. CC19 was 8.0%, 30.8% and 5.2%, respectively, compared to 81.2% for the control. Therefore, B. subtilis B29 could be a prospective antagonist for biological control of powdery mildew, downy mildew and gray mold of cucumber plant.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.2
• /
• pp.233-240
• /
• 2016

FK506, a widely used immunosuppressant, is a 23-membered polyketide macrolide that is produced by several Streptomyces species. FK506 high-yielding strain Streptomyces sp. RM7011 was developed from the discovered Streptomyces sp. KCCM 11116P by random mutagenesis in our previous study. The results of transcript expression analysis showed that the transcription levels of tcsA, B, C, and D were increased in Streptomyces sp. RM7011 by 2.1-, 3.1-, 3.3-, and 4.1-fold, respectively, compared with Streptomyces sp. KCCM 11116P. The overexpression of tcsABCD g enes in Streptomyces sp. RM7011 gave rise to approximately 2.5-fold (238.1 μg/ml) increase in the level of FK506 production compared with that of Streptomyces sp. RM7011. When vinyl pentanoate was added into the culture broth of Streptomyces sp. RM7011, the level of FK506 production was approximately 2.2-fold (207.7 μg/ml) higher than that of the unsupplemented fermentation. Furthermore, supplementing the culture broth of Streptomyces sp. RM7011 expressing tcsABCD genes with vinyl pentanoate resulted in an additional 1.7-fold improvement in the FK506 titer (498.1 μg/ml) compared with that observed under non-supplemented condition. Overall, the level of FK506 production was increased approximately 5.2-fold by engineering the supply of allylmalonyl-CoA in the high-yielding strain Streptomyces sp. RM7011, using a combination of overexpressing tcsABCD genes and adding vinyl pentanoate, as compared with Streptomyces sp. RM7011 (95.3 μg/ml). Moreover, among the three precursors analyzed, pentanoate was the most effective precursor, supporting the highest titer of FK506 in the FK506 high-yielding strain Streptomyces sp. RM7011.

• KSBB Journal
• /
• v.15 no.2
• /
• pp.150-155
• /
• 2000

Antioxidative activity of c비ture of Streptomyces sp. BH-405 was investigated. After removal of pellets of Streptomyces sp. B BH-405, antioxidative substances were is미ated and suc$\infty$sively purified from culture of Streptomyces sp. BH-405 by by thin | layer chromatography $\pi$LC) or silica gel column chromatography. The fraction 3 obtained from ethylether fractionation of the C culture appeared highest level of anti oxidative activity as determined by thiocyanate method. Band 2 obtained by further P purification of this fraction showed higher anti oxidation level than that of same concentration of dl- $\alpha$ -tocopherol, butylated h hydroxy anisole (BHA). The band 2 showed higher rate of 1, 1.diphenyl 2-picrylhydrazyl (DPPH) decolorization than dl-$\alpha$-tocopherol. In the rat liver microsomes, band 2 rapidly inhibited lipid peroxidation which was initiated enzymatically by r reduced nicotinamide adenine dinucleotide phosphate (NADPH) or non-enzymatically by Fenton’s reagent. Band 2 inhibited on | lipid peroxidation of mitochondria or the linoleic acid hydro peroxide induced peroxidation system. It is concluded that band 2 obtained by fractionation of Streptomyces sp. BH-405 cultivation contained antioxidants with the capacity to inhibit oxidative m modification.

• Korean Journal of Soil Science and Fertilizer
• /
• v.25 no.4
• /
• pp.401-406
• /
• 1992

Antifungal substances against three plant pathogenic fungi, Phytophthora capsici, Phytophthora nicotianae var. parasitica and Rhizoctionaia solani were fractionated cultures of Streptomyces sp. A-2 strain isolated in Korean soils. Characterizations of active substances related with antagonistic effects were follows : 1. The excellent media which showed the transfer efficiency of antagonistic substances from Streptomyces sp. A-2 strain G.Y.B and B.H.I. among four that are glucose yeast broth (G.Y.B), $M\ddot{u}eller$, brain heart infusion(B.H.I.) and Czapek media. Active substances which were transfered into ethylacetate or left in residual aqueous phase did not lose antagonistic activity in spite of autoclavation. This indicated that bonds of these compounds were rigid enough to keep activity under such conditions. 2. Antagonistic substances were extracted according to adjustment of pH 3 or pH12 to 5 day-old B.H.I. broth cultures of Streptomyces sp. A-2 strain. Comparative analysis fluorescent bands on HPTLC to antagonsitic spectra against three phytopathogenic fungi indicated that major substances with antagonistic activity were extracted regardless of different pH adjustment to broth cultures. Since UV spectrum of these fractions scanned from 500nm to 200nm was similiar to that of polyene macrolide, major substances related with antagonistic activities were assumed to be polyene derivatives antibiotics.

• The Korean Journal of Food And Nutrition
• /
• v.2 no.1
• /
• pp.1-11
• /
• 1989

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 from soil The optimum temperature, pH, and pH stability were 6$0^{\circ}C$, 10.5, and 7.8, respectively. The production of Gl in xylose and yeast extract was higher than that of other carbon source and nitrogen source. The Gl production was affected by Co2+ and Mg2).

• Applied Biological Chemistry
• /
• v.38 no.2
• /
• pp.100-105
• /
• 1995

Media optimization for the production of MR-387A and B, novel aminopeptidase M inhibitors by Streptomyces sp. SL-387 isolated from a soil was studied. Optimized medium was consisted of 1% glucose, 3% soybean meal, 0.2% yeast extract, 0.1% beef extract, 0.3% NaCl, 0.01% $K_2HPO_4$, 0.3% $CaCO_3$, 0.001% $MnCl_2{\cdot}4H_2O$, 0.001% $ZnCl_2{\cdot}7H_2O$, and 0.0005% $MgSO_4{\cdot}7H_2O$, and adjusted to pH 7.0 before autoclaving. When the optimized medium was used as a fermentation medium, maximum productivity of MR-387 was reached at 120 hours of fermentation, and total productivity was 909.1 U/ml.

• Microbiology and Biotechnology Letters
• /
• v.23 no.1
• /
• pp.47-52
• /
• 1995

Since the original productivity of new aminopeptidase M inhibitors MR-387A and B by Streptomyces sp. SL-387 (KCTC 0102BP) was not enough for further chemical and biological evaluation, mutation of parent strain by the treatment of N-methyl-N'-nitro-N-nitrosoguanidine was performed in order to obtain a clone with greater inhibitory activity. Mutant N-3 was selected due to a 6-fold greater productivity (40 $\mu$g/ml) than that of the wild type(6.7 $\mu$g/ml). This mutant was resistant to 3,4-dehydro-DL-proline, an antimetabolite of proline, with 25 $\mu$g/ml of minimum inhibitory concentration. Furthermore, the characteristic morphological change from spiral spore chain in wild type to straight in mutant was observed. An aminopeptidase M nhibitor different from MR-387A and B was isolated from the culture broth of the mutant. This inhibitor was composed of 2 proline, 1 valine, and an unknown amino acid which is presumably 3-amino-4-phenylbutanoic acid. IC$_{50}$ value (89.1 $\MU$g/ml) of the purified inhibitor was lower than that of other inhibitors, which may be due to the absence of 2(S)-hydroxyl group within the structure of 3-amino-4-phenyl- butanoic acid.