• Korean Journal of Pharmacognosy
• /
• v.15 no.1
• /
• pp.15-23
• /
• 1984

To find antimicrobial strains of the soil microorganisms in Korea, they were isolated from the soil samples of different locations and screened for antibiotic activity against several standard microbes. An isolate among them had an antibacterial activity against gram-positive bacteria. The examination of its morphological and biochemical characteristics according to the International Streptomyces Project methods showed that it belongs to the genus Streptomyces. The strain was named DMC-72. The strain appears to be a new strain when it was compared with the species within the genus which have been so far reported. The antibiotic metabolite of the strain was produced in submerged culture method. It was found to be a quinone compound and was named soulomycin. This strain was also found to produce an ${\alpha}-amylase$ inhibitor in the submerged culture.

• The Korean Journal of Mycology
• /
• v.13 no.4
• /
• pp.203-212
• /
• 1985

Of 450 strains isolated from the soil microbes collected in various locations in Korea, a strain had a strong inhibitory activity against bacterial ${\alpha}-amylase$ and was named strain DMC-72 of the genus Streptomyces. The amylase inhibitory metabolite produced by this strain was purified by means of acetone precipitation, adsorption on Amberlite IRC-50 and SP-Sephadex C-25. The inhibitor was found to be a derivative of oligosaccharides by spectral and chemical data. The inhibitor was stable at the pH range of $1{\sim}13$ and at $100^{\circ}C$ for half an hour, also inhibited other amylases such as salivary ${\alpha}-amylase$, pancreatic ${\alpha}-amylase$, fungal ${\alpha}-amylase$ and glucoamylase. However, it showed no inhibitory activity against ${\alpha}-glucosidase$, ${\beta}-glucosidase$, dextranase, and ${\beta}-amylase$. The kinetic studies of the inhibitor showed that its inhibitory effects on starch hydrolysis by ${\alpha}-amylase$ were noncompetitive.