• Microbiology and Biotechnology Letters
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• v.23 no.5
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• pp.519-525
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• 1995

This study was carried out to enhance the production of sisomicin by Micromonospora inyoensis ATCC 276000. The effect of various sugars and organic acids as the supplements to a basal mineral medium was tested for the sisomicin production by fully grown mycelium. Among the substances tested, acetate and citrate greatly increased the production of sisomicin at the sixth day of culture. Especially, in the basal mineral medium containing 0.1M sodium acetate, sisomicin production was 6.7 times more than that in the same medium with glucose. When 0.1M sodium acetate was added in the fermentation medium initially, the cell growth was inhibited by sodium acetate, although specific productivity was higher than that in the same medium without sodium acetate. On the contrary, when sodium acetate was added to the culture after three days, the sisomicin production and specific productivity were 1.6 times higher than those in the same medium without sodium acetate. The results suggested that sodium acetate was a stimulating substance of sisomicin production by M. inyoensis.

• Microbiology and Biotechnology Letters
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• v.14 no.5
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• pp.355-358
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• 1986

The effects of cobalt chloride, methionine, and various carbon sources on the sisomicin production by M. inyoensis NRRL 3292 were investigated. It was found that both cobalt chloride and methionine exerted a greater stimulatory effect on sisomicin formation. Kinetic studies with various carbon sources revealed thai polysaccharide such as starch or dextrin was found io be better than glucose for sisomicin production Moreover, the relatively low concentration of dissolved carbon dioxide was one of the most important factors In accelerating sisomicin production during idiophase.

• Microbiology and Biotechnology Letters
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• v.14 no.4
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• pp.293-298
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• 1986

Sisomicin, which is one of aminoglycoside antibiotics, was produced by Micromonospora inyoensis. The effects of carbon sources on sisomicin production were studied in batch cultures. Starch, dextrin and maltose were good carbon sources for the production of sisomicin. However, when glucose was used, the antibiotic productivity decreased significantly due to a carbon catabolite regulation. The carbon catabolite regulation depends mostly on carbon catabolite repression, but not on carbon catabolite inhibition. On the other hand, the growth-production curves of batch cultures show that sisomicin is produced most actively during the idiophase.

• Microbiology and Biotechnology Letters
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• v.14 no.4
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• pp.271-277
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• 1986

A sisomicin-producing strain, Micromonospora inyoensis, was treated with various mutagens. The optimal death rates to obtain the high-producers of sisomicin were 90% for ultraviolet light, 99% for nitrosoguanidine, and 99.3% for nitrous acid, respectively. In place of the method of liquid culture, an agar plug method, which is easy and convenient, was used to measure the antibiotic-producing abilities of the strains isolated from mutagen-treated cells. On the other hand, as the selection method of overproducing mutants after mutagenesis, gradient agar plates which included various antibiotics and salts were used. Among the antibiotics and salts tested, gentamicin and kanamycin as antibiotics, and CuCl$_2$ and HgCl$_2$ as salts, were effective to select the high-producers of sisomicin.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1986.12a
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• pp.514.2-514
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• 1986

Since sisomicin which is produced by Micromonospora inyoensis is an intracellular antibiotic, the final antibiotic titer to be attained depends singnificantly on the cell mass in fermentation broth. Cobalt ion in medium was indispensable for getting a high antibiotic titer. However, in the presence of cobalt ion in medium, the antibiotic production proceeded up to about 4 days and thereafter stopped. From the experiments on theaddition of cobalt ion to culture medium, it was shown that the antibiotic production stopped due to the other physiological properties of cells rather than the accumulation of antibiotic in cells.