• Applied Biological Chemistry
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• v.38 no.6
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• pp.512-515
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• 1995

In order to examine the effect of rehydration methods on viability after freeze-drying of Streptomyces aureofaciens, we labeled the DNA of S. aureofaciens with $^3H-adenine$. Extracellular radioactivity levels appeared to be high in the rehydrated solutions after freeze-drying than freezing-thawing. In effects of rehydration after freeze-drying, the viability of the cell appeared about 20% in case of with admitting air at single ampule, but that of which appeared about 91% in case of without admitting air at double ampule. Thus, S. aureofaciens cells were damaged during the process of rehydration after freeze-drying.

• Archives of Pharmacal Research
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• v.13 no.1
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• pp.28-32
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• 1990

Precipitation and purification of amylase secreted by Streptomyces aureofaciens 77 in liquid inorganic salts-starch medium under the optimum conditions were carried out. Ammonium sulphate fractionation was used to precipitate amylase in cell free culture filtrate. (NH/sub 4/)/sub 2/ SO/sub 4/ at a concentration of 50-70% saturation gave the highest enzyme yield. The obtained precipitates were redissolved in phosphate buffer (pH 7.0) and subjected to dialysis. The dialyzed enzyme preparation was applied to DEAE-cellulose column chromatography which resulted in an increase of purification up to 59.48 fold. A further step of purification was done by applying the obtained purified sample to Sephadex-G200 column chromatography which resulted in ann increase of purification up to 73. 92 fold. The results clearly indicated that the isolated amylase from S. aureofaciens 77 was only on type.

• Journal of Microbiology and Biotechnology
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• v.3 no.3
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• pp.174-180
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• 1993

A strain SMF14 producing an extracellular $\beta$-lactamase was isolated from soil and identified to be a strain of Streptomyces aureofaciens. $\beta$-Lactamase was purified from the cell free culture broth through batchwise hydroxyapatite adsorption, anion exchange chromatography on DEAE Sephadex A-50, gel filtration on Sephadex G-75, and adsorption chromatography on hydroxyapatite. The molecular mass was estimated to be about 43 kDa by SDS-PAGE. The $\beta$-lactamase had substrate specificity to penicillins and it was inhibited by clavulanic acid, being classified to the group 2a of penicillinase.. The optimal reaction pH and temperature were pH 6.0~7.5 and $50^{\circ}C$. The $K_m, and V_{max}$ values of $\beta$-lactamase for penicillin G were calculated to be 1.72 mM and 5.4$\times$$10^5 \mu M \cdot min^{-1}$, respectively.

• YAKHAK HOEJI
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• v.32 no.5
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• pp.295-303
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• 1988

For microbial production of acetaminophen, a popular analgesic-antipyretic from aniline, we screened various fungi and bacteria. And we succeeded to some extents in acetaminophen production by successful protoplast fusion between S. lividans and S. globisporus and also between S. rimosus and S. aureofaciens. However, more fertile results might be brought via performing the cloning of acetanilide p-hydroxylation genes of Streptomyces in yeast. This study was initiated to determine whether the acetanilide p-hydroxylase of Streptomyces is cytochrome P-450 species or non-heme iron protein species. The p-hydroxylationactivity on acetanilide in S. aureofaciens ATCC 10762 was found to be unstable on exposing to the air. However, 100,000xg supernatant of the cell free extracts which were prepared in $N_2$ atmosphere showed the p-hydroxylation activity. Characteristic absorption peak of cytochrome P-450 after reduction with dithionite and addition of CO was not observed in the region of 450nm. Moreover, metyrapone and 2, 6-dichloroindophenol did not affect this enzyme activity, but sodium azide, sodium cyanide, cupric sulfate, cadmium chloride, ${\alpha}$, ${\alpha}'-dipyridyl$, and o-phenanthroline reduced p-hydroxylase activity considerably. S. fradiae NRRL 2702 was shown to have strong p-hydroxylation activity in intact cells. This activity disappeared in its cell free extracts. In its 100,000xg supernatant, however, characteristic absorption peak of cytochrome P-450 after reduction with dithionite and addition of CO was observed at 446nm. Thus, the results herein presented suggest that acetanilide p-hydroxylase of Streptomyces aureofaciens is not related to cytochrome P-450 and may include non-heme iron protein for its activity. However, it is not clear whether acetanilide p-hydroxylase in S. fradiae belongs to the same category of S. aureofaciens.

• Microbiology and Biotechnology Letters
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• v.25 no.3
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• pp.317-321
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• 1997

The effect of ammonium ion concentration on the production of demethyl- chlortetracycline (DMCT) by a DMCT overproducing mutant, Streptomyces aureofaciens 27VR, and the optimal control of pH were studied. The optimum levels of pH control were 6.5-6.6 for 80-120 hr, 6.4- 6.5 for 121-150hr and 6.3-6.4 for 151-190hr. The optimum level of ammonium ion concentration during the pH control was lower than 20 mg%. Under the optimized culture condition, it was possible to produce DMCT with an 18% increase in productivity compared to that of standard culture condition in 190hrs of the fermentor operation.

• Korean Journal of Microbiology
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• v.18 no.3
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• pp.115-122
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• 1980

We have demonstrated that both L-histidine as an amino acid factor and dextrin as a carbon source were required for the glucose repression. 1% glucose was sufficient to the glucose repression of aerial mycelium formation in Streptomyces lavendulae and Streptomyces aureofacience. the synthesized medium, KK, which is lack of all orgnic nutrients except dextrin was able to induce glucose repression, but the addition of 0.003% or more L-histidiner recovers the capacity of glucose repression. 0.02% or more histidine was reuqired for glucose repression of aerial mycelium formation in the absence of dextrin. Treatments of $5{\mu}M$ ormore ethidium bromide (EtBr0 gave rise to bald mutants at high frequency in Streptomyces aureofaciens, and it is probable that the gene(s) for the function of aerial mycelium formation is linked to plasmed DNA in this species.

• Archives of Pharmacal Research
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• v.13 no.1
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• pp.33-37
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• 1990

The effects of pH values, temperature and some elements on the amylolytic activity and stability of the purified S. aureofacienc 77 amylase were studied in this investigation. The purified enzyme showed its maximum activity at pH 6 within 8 min incubation at $40^{\circ}C$. None of the tested 6 metals showed on stimulatory effect on the enzymatic activity, $Fe^{+++}$, $Cu^{++}$ and $Hg^{++}$ at high dose inhibited the enzyme activity to great extent as compared with $Zn^{++}$, $Mn^{++}$ and $Fe^{++}$ whih gave less effect in this respect. The enzyme liquor was found to be thermolabile, since it lost completely its activity after 4 days incubation under room temperature and showed maximum activity during this period as a result of additions of $Ca^{++}$and NaCl, Gradual reduction was however recorded until activity reached 30% after 60 days of incubation.

• Journal of Microbiology
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• v.44 no.4
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• pp.432-438
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• 2006

Twelve actinomycete strains were isolated from Egyptian soil. The isolated actinomycete strains were then screened with regard to their potential to generate antibiotics. The most potent of the producer strains was selected and identified. The cultural and physiological characteristics of the strain identified. the strain as a member of the genus Streptomyces. The nucleotide sequence of the 16S rRNA gene (1.5kb) of the most potent strain evidenced a 99% similarity with Streptomyces spp. and S. aureofaciens 16S rRNA genes, and the isolated strain was ultimately identified as Streptomyces sp. MAR01. The extraction of the fermentation broth of this strain resulted in the isolation of one major compound, which was active in vitro against gram-positive, gram-negative representatives and Candida albicans. The chemical structure of this bioactive compound was elucidated based on the spectroscopic data obtained from the application of MS, IR, UV, $^1H$ NMR, $^{13}C$ NMR, and elemental analysis techniques. Via comparison to the reference data in the relevant literature and in the database search, this antibiotic, which had a molecular formula of $C_{19}H_{29}NO_2$ and a molecular weight of 303.44, was determined to differ from those produced by this genus as well as the available known antibiotics. Therefore, this antibiotic was designated Meroparamycin.

• Archives of Pharmacal Research
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• v.15 no.1
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• pp.30-34
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• 1992

In order to obtain acetaminophen, a popular analgesic-antipyretic, through microbial p-hydroxylation and N-acetylation of aniline, various fungi and bacteria were secreened. Among them, Streptomyces species were chosen for strain improvement by the use of interspecific protoplast fusion technique. Two interspecific fused strains were developed between S. rimosus (N-cetylation function) and S. aureofaciens (p-hydroxylation function) and also between S. lividans and S. globisporus. For efficient protoplast fusion and cell wall regeneration, various conditions were examined. In a typical experiment of mixed S rimosus ($pro^- \;his^-$) and S. aureofaciens ($ilv^-$) protoplasts with 40% (w/v) polythylene glycol 3350 (PEG) for 3 min gave $8.3\times10^{-7}$ of fusion frequency. Treatment of mixed S. lividans (pant-) and S. globisporus (leu-) protoplasts with 50% (w/v) PEG for 3 min at $30^\circ{C}$ gave $1.2\times10^{-6}$ of frequency. Among the fused strains, up to 40-50% increase in p-hydroxylation power was observed. To investigate the possibility of plasmid involvement in p-hydroxylation power was observed. To investigate the possibility of plasmid involvement in p-hydroxylation of acetanilide, plasmid curing was attempted. We found that cells treated with acriflavine (at the frequency of 100%) and cells regenerated from protoplsts of S. auroefaciens (2% frequency) lost their p-hydroxylation function.

• Journal of Microbiology
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• v.45 no.3
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• pp.262-267
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• 2007

During a screening program, an actinomycete strain isolated from the Egyptian soil was investigated for its potential to show antimicrobial activity. The identification of this isolate was performed according to spore morphology and cell wall chemo-type, which suggested that this strain is a streptomycete. Further cultural, physiological characteristics and the analysis of the nucleotide sequence of the 16S rRNA gene (1480 bp) of this isolate indicated that this strain is identical to Streptomyces violaceusniger (accession number EF063682) and then designated S. violaceusniger strain HAL64. In its culture supernatant, this organism could produce one major compound strongly inhibits the growth of Gram-positive but the inhibition of Gram-negative indicator bacteria was lower. The antibiotic was separated by silica gel column chromatography and then purified on a sephadex LH-20 column and finally the purity was checked by HPLC. The chemical structure of the purified compound was determined using spectroscopic analyses (molecular formula of $C_{33}H_{32}N_{2}O_{10}$ and molecular weight of 617.21) and found to be identical to the kosinostatin, a quinocycline antibiotic which is known to be produced by Micromonspora sp. TP-A0468 (Igarashi et al., 2002) and to quinocycline B isolated from Streptomyces aureofaciens (Celmer et al., 1958). Although the antibiotic is known, the newly isolated strain was able to produce the antibiotic as a major product providing an important biotechnological downstream advantage.