Optimization of Cultural Conditions for Production of Antibacterial Metabolites from <i>Streptomyces coelicoflavus</i> BC 01

Abstract

The aim of the present study was to optimize various cultural conditions for the production of antibacterial metabolites by Streptomyces coelicoflavus BC 01 isolated from mangrove soil, Visakhapatnam, Andhra Pradesh, India. The effect of various factors such as carbon and nitrogen sources, different concentrations of NaCl and K2HPO4, different temperature, pH, incubation time and agitation on antibacterial metabolites production were studied. The production of antibacterial metabolites by the isolate Streptomyces coelicoflavus BC 01 was greatly influenced by the cultural conditions. Glucose (1.2%) and soya bean meal (1%) seemed to be the best carbon and nitrogen source respectively, followed by NaCl (1%) and K2HPO4 (0.25%). Maximum production of antibacterial metabolites was observed at a temperature of 30 °C, with pH 7.2, at 160 rpm for 96 hrs. These optimized parameters can be further useful to design a fermentation medium to achieve maximum yield of antibacterial metabolites from Streptomyces coelicoflavus BC 01.

Characterization of Streptomyces sp. KB1 and its cultural optimization for bioactive compounds production

“…KB1 (TISTR 2304) showed a narrow range of incubation temperatures for BC production and the most suitable incubation temperature for the maximum production of BCs was 30 °C. This finding coincided with research by Raghavarao et al (2015) who reported that Streptomyces coelicoflavus BC01 could produce BCs at incubation temperatures between 15 °C to 45 °C, but the optimal temperature was 30 °C. In addition, this finding was in accordance with the results of Bundale et al (2015) who reported that the optimal temperature for the production of BCs for the three Streptomyces species in their study was 30 °C.…”

“…This finding was in accordance with research from Augustine, Bhavsar & Kapadnis (2005) who reported that Streptomyces rochei AK39 could produce the maximum amount of cephalosporin C at an agitation rate of 200 rpm. Moreover, this finding also coincided with research from Raghavarao et al (2015) who reported that the production of antibacterial metabolites by Streptomyces coelicoflavus BC01 decreased when agitation speed increased ( Raghavarao et al, 2015 ). The decrease of BC production of Streptomyces species at high agitation speeds indicated that it was affected by the death or damage of cells by shearing forces caused from agitation at high speed ( Lee et al, 2014 ).…”

“…KB1 (TISTR 2304). Agitation affected the mixing of nutrients and amount of dissolved oxygen in the medium, which directly influenced BC production ( Raghavarao et al, 2015 ). This finding was in accordance with research from Augustine, Bhavsar & Kapadnis (2005) who reported that Streptomyces rochei AK39 could produce the maximum amount of cephalosporin C at an agitation rate of 200 rpm.…”

“…A carbon source usually constitutes the major part of a culture medium because it can readily serve as growth substrates. Several studies have shown the effect of different carbon sources on the production of BCs of Streptomyces species ( Jonsbu, McIntyre & Nielsen, 2002 ; Sharon, Daniel & Shenbagarathai, 2014 ; Raghavarao et al, 2015 ). It was found that simply metabolizable carbon sources generally repressed secondary metabolism or the biosynthesis of BCs ( Escalante et al, 1982 ).…”

“…Meanwhile, the use of ammonium sulphate and urea, which are inorganic nitrogen sources, create high ammonium concentrations in culture medium and suppress BC production in many microorganisms including Streptomyces sp. KB1 (TISTR 2304) ( Rafieenia, 2013 ; Raghavarao et al, 2015 ).…”