• Korean Journal of Microbiology
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• v.15 no.2
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• pp.93-99
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• 1977

Among the Streptomyces isolated from soil, two strains which have antibacterial activity aginst various pathogenic bacteria are identified as Streptomyces globosus and Streptomyces albus subsp. according to I.S.P. methods and Bergy's Manual of Determinative Bacteriology. Morphological and physiological characteristics of them on several media were observed. Antibiotics from S. albus subsp. or S. globosus was identified asw tetracycline or streptomycin-like substances respectively by the paper chromatographic behavior in eight solvent systems of V. Betina. And it was revealed that these antibiotic substances are stable to temperature and weak acid.

• The Korean Journal of Food And Nutrition
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• v.11 no.4
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• pp.381-387
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• 1998

The effects of culture conditions on the production of amylase expressed by Bacillus subtilis LKS88 with a cloned gene from Streptomyces albus KSM-35 were investigated. The production of amylase was increased significantly by using sodium citrate and rice hull as a carbon source. In addition, the use of a mixture of sodium citrate and rice hull (1:1) resulted in increase of enzyme production by 20-fold when compared to that of soluble starch. The soybean meal as the nitrogen source could be partially replaced with yeast extract without changing the enzyme production yield. The amylase production was also increased by adjusting initial pH to 6.0 or by adding 0.01% SDS. Maximum amylase production was observed in the medium containing 1.5% sodium cirtate, 1.5% rice hull, 0.7% soybean meal, 0.3% yeast extract, 0.66% K2HPO4, 0.05% MgSO4$.$7H2O, 0.008% CaCl2$.$2H2O, 0.01% SDS with initial pH of 6.0. The maximum yield of amylase reached 56.6 U/ml when B. subtilits LKS88 (pASA 240) was cultured at 37$^{\circ}C$ for 36 hr.

• Journal of Microbiology
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• v.44 no.1
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• pp.50-53
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• 2006

Cys-29 and Cys-251 of Streptomyces albus valine dehydrogenase(ValDH) were highly conserved in the corresponding region of $NAD(P)^+$-dependent amino acid dehydroganase sequences. To ascertain the functional role of these cysteine residues in S. albus ValDH, site-directed mutagenesis was performed to change each of the two residues to serine. Kinetic analyses of the enzymes mutated at Cys-29 and Cys-251 revealed that these residues are involved in catalysis. We also constructed mutant ValDH by substituting valine for leucine at 305 by site-directed mutagenesis. This residue was chosen, because it has been proposed to be important for substrate discrimination by phenylalanine dehydrogenase (PheDH) and leucine dehydrogenase (LeuDH). Kinetic analysis of the V305L mutant enzyme revealed that it is involved in the substrate binding site. However it displayed less activity than the wild type enzyme toward all aliphatic and aromatic amino acids tested.

• Microbiology and Biotechnology Letters
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• v.23 no.2
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• pp.178-186
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• 1995

Streptomyces albus wild type ATCC 21838 produced salinomycin, polyether antibiotic. To clone genes related salinomycin production, a genomic library was screened using actI as a DNA hybridization probe. pWHM 210 was isolated, which contained an approximately 24 kb of insert DNA. A 3.8 kb region in the 24 kb insert DNA was hybridized to actI and the nucleotide sequence of this region was determinied. Two open reading frames found in the same direction were homologous to genes for $\beta$-keto acyl synthase/acyl transferase and chain length determining factor in type II PKS (polyketide synthase). The genes were components of minimal type II PKS genes, highly conserved and showed the strong simiarity to other type II PKS genes known today.

• Journal of Microbiology
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• v.35 no.1
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• pp.40-46
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• 1997

The pWHM220 cosmid with a 24-kb insert cloned from Streptomyces albus ATCC 21838 induces the biosynthesis of a polysther antibiotic similar to salinomycin in Streptomyces invidans. We have analyzed this region by DNA sequencing as well as Southern blot hybridization with type I and type II polyketide synthase (PKS) probes. Surprisingly, we found another set of type II SKS genes only 10-kb from the original PKS genes, salABCDE. The DNA sequence revealed two complete open reading frames (ORFs) named salB2 and salC2, and one partial ORF that does not resemble any known DNA or deduced protein sequence. The salC2 should code for chain length determining factor while the deduced amino acid sequence encoded by salB2 exhibits high similarity to .betha.-ketoacyl synthase from different PKS gene clusters. The highest identity was found for .betha.-keetoacyl synthases from S. argillaceus (MtmP. 59.1% identity), the mithramycin producer and from S. venezuelae ISP5230 (JadA, 52.3% identity), the jadomycin producer. The SalC2 protein clearly resembles its counterparts in order aromatic PKS gene clusters that are believed to influence the length of the polyketide chain. The highest identities observed were to that of S. argillaceus (MtmK, 62.3%) and S. venezuelae ISP 5230 (JadB, 55.1%) proteins, Moreover, the deduced amino acid sequences of the salB2 and salC2 products were 29.0% identical.

• Journal of Microbiology and Biotechnology
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• v.17 no.10
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• pp.1675-1681
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• 2007

The pseudodisaccharide salbostatin, which consists of valienamine linked to 2-amino-1,5-anhydro-2-deoxyglucitol, is a strong trehalase inhibitor. From our Streptomyces albus ATCC 21838 genomic library, we identified thirty-two ORFs in a 37-kb gene cluster. Twenty-one genes are supposed to be a complete set of modules responsible for the salbostatin biosynthesis. Through sequence analysis of the gene cluster, some of the upstream gene products (SalB, SalC, SalD, SalE, and SalF) revealed functional resemblance with trehalose biosynthetic enzymes. On the basis of this rationale, we isolated the five genes (salB, salC, salD, salE, and salF) from the S. albus ATCC 21838 and cloned them into the expression vector pWHM3. We demonstrated the noticeable expression and accumulation of trehalose, using only the five upstream biosynthetic gene cluster of salbostatin, in the transformed Streptomyces lividans TK24. Finally, 490 mg/l trehalose was produced by fermentation of the transformant with sucrosedepleted R2YE media.

• Journal of Microbiology and Biotechnology
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• v.9 no.4
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• pp.488-497
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• 1999

Probing Streptomyces albus ATCC 21838 chromosomal DNA with a proline tRNA sequence resulted in an isolation of a putative integrating element in the 6.4-kb EcoRI fragment. It was found that Streptomyces lividans TK-24 transformed with a cloned DNA fragment on a multicopy plasmid, produced a higher level of spore pigment and mycelial red pigment on a regeneration agar. Furthermore, the transformant S. lividans TK-24 produced a markedly increased level of undecylprodigiosin in a broth culture. A nucleotide sequence analysis of the cloned region revealed several open reading frames homologous to the integrases of integrating plasmids or temperate bacteriophages, signal-transducing regulatory proteins with a conserved ATP-binding domain, oxidoreductases ($\beta$-ketoacyl reductase), and an AraC-like transcriptional regulator. To examine the effect on antibiotic production, each coding region was overexpressed separately from the other genes in the region in S. lividans TK-24 with; pJHS3044 for the expression of the signal-transducing regulatory protein homologue, pJHS3045 for the homologue of oxidoreductase, and pJHS3051 for the homologue of the AraC-like transcriptional regulator. Phenotypic studies of S. lividans TK-24 strains harboring plasmids for the overexpression of individual genes suggested the following effects of the genes on antibiotic production: The oxidoreductase homologue stimulated the production of actinorhodin and undecylprodigiosin, which was influenced by the culture conditions; the homologue of the AraC-like transcriptional regulator was the most effective factor in antibiotic production within all the culture conditions tested; the signal-transducing regulatory protein homologue repressed the effect due to the homologue of the AraC-like transcriptional regulator, however, the antibiotic production was derepressed upon entering the stationary phase.

• Korean Journal of Microbiology
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• v.15 no.3
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• pp.123-130
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• 1977

In previous paper, it was reported that antibiotic substance such as tetracycline and streptomycin were produced by S'. albus subsp. and S'. globosus. And increase of mycelial growth of two strains, antibiotic production, and changes of pH range are extended to approximately 110-130 hrs in fermenting medium, there-after they decreased with culture period exception of pH range. Two Streptomyces spp. required commonly 4-5% starch as carbon sources and 1.5-2.0% soybean meal as nitrogen sources. However, 0.005-0.01M potassium phosphate dibasic, calcium carbonate (6mg/ml in S.albus subsp. and 2mg/ml in S. globosus), 0.01-0.03M, magnesium sulgate and 0.01M ferric chloride showed as optimal concentration for the growth of 2 strains. Mineral compoments such as zinc, manganese, cobalt, sodium and copper at the level of 10/sup -4/ -10/sup -6/M were observed. Especially, zinc ion showed toxicity to the growth of 2 strains at 0.005M. In relation with pH, there is a little difference in mycelial growth with cultural initial pH.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1426-1431
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• 1998

The research was undertaken to characterize enzymatic properties of Streptomyces albus amylase expressed in recombinant Bacillus subtilis. Molecular weight and pI of the purified enzyme were estimated to be 50 kD by SDS-PAGE and 4.3 by isoelectric focusing. The optimum temperature and optimum pH were $45^{\circ}C$ and 6.0, respectively. D-and Z-value were estimated to measure thermostability of the purified enzyme. The Z-value was estimated $17.7^{\circ}C$, which is lower than typical amylase. Maltotetraose was produced as a major component from soluble starch in the early state of reaction but gradually degraded to maltose. Thin layer chromatography was also performed to analyze the reaction products. The parameters involved in Michaelis-Menten enzyme kinetics were found to be the maximum velocity of 0.37 mM/min and the Michaelis constant of 0.13%, respectively.

• Journal of Microbiology and Biotechnology
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• v.5 no.2
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• pp.74-79
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• 1995

Sequence analysis of a DNA region encompassing the site of hybridization to actl, the gene for type II minimal polyketide synthase (PKS) for actinorhodin biosynthesis, from Streptomyces ablus revealed three more complete open reading frames additional to the already found two genes, plausibly encoding ${\beta}-ketoacyl$ synthase/acyl transferase (KS/AT) and chain length determining factor (ClF). The open reading frames (ORFs) were named salA, salD, and salE, from the upstream. In the homology analysis of the deduced amino acid sequences, SalA resembles the Streptomyces glaucescens Tcml, decaketide cyclase, SalD resembles acyl carrier protein in type II PKS, and SalE resembles the Actlll ketoreductase, The whole 4.4 kb of DNA sequence obeys the same conservation pattern as other type II PKSs. Therefore, we suggest that the 4.4 kb DNA from Streptomyces albus encompasses genes encoding enzymes for polyketide biogenesis in the organism and its organization is type II. The exsitence of SaIA, an analogue of the aromatic cyclase, revealed a relatedness of the 4.4 kb DNA with the aromatic PKS.