ISOLATION AND SELECTION OF ACTINOMYCETES STRAINS CAPABLE OF PRODUCING ANTIBIOTICS FROM A PLANTED LAND IN QUOC OAI DISTRICT, HANOI

Abstract

In this study, we isolated and selected actinomycetes strains with antibiotic activity from cultivated soil in Quoc Oai district, to orient the search for new antibiotic compounds. 89 strains of actinomycetes have been isolated, divided into 4 color groups with different ratios: white (36.0%); gray (34.8%); yellow  (18.0%) and brown (11.2%). In which, 44 strains inhibited Escherichia coli, 11 inhibited strains of Baccilus subtilis and 9 were resistant to both types of microorganisms tested above. The selection of strain CH8.1 has the strongest antibacterial activity against the two types of microorganisms mentioned above. A survey on ISP2 medium showed that CH8.1 has the best growth at 28^oC, neutral pH, NaCl concentration is 4%. A survey on growth on ISP9 medium shows that CH8.1 is capable of using a variety of sugar sources such as: D- glucose, succrose, D-galactose, mantose, D- cellobiose, raffinose. Based on the classification of the International Sterilizer Program (ISP), combined with the 16S rDNA sequence of strain CH8.1 is named Streptomyces manipurencis CH8.1.