OPTIMIZATION OF CULTIVATION PARAMETERS FOR GROWTH AND PIGMENT PRODUCTION BY Streptomyces spp. ISOLATED FROM MARINE SEDIMENT AND RHIZOSPHERE SOIL
|V Palanichamy*, Aachhari Hundet, Bhaskar Mitra and Narayana Reddy
|Related article at Pubmed, Scholar Google|
Biological pigments are a better substitute to chemical dyes used in the industries and laboratories. Out of the many species of Streptomyces present ubiquitously in soil, S. coelicolor and S. violaceoruber produce an important red-blue antibiotic actinorhodin and associated compounds like α-, β-, ε-, γ-actinorhodin collectively known as Actinorhodin-Related “Blue Pigments”. These pigments have a wide range of applications in scientific, medical and industrial sector. So, it is a beneficial alternative method to isolate these microorganisms and extract actinorhodin, rather than producing chemical colouring agents which have harmful effects on humans and environment. Several solid media are available to cultivate these species but it is difficult to extract the pigment using solid substrate. There are many liquid media which support the growth of the organism, but since pigment production depends greatly on culture conditions, it is necessary to standardize the various parameters that may affect the product quality and quantity. Therefore, an optimum culture media has to be formulated. The soil samples were collected from fields and coastal areas of Chennai and Streptomyces species were isolated. The cultures were screened for actinorhodin production and biochemical characterization was done. It was mass multiplied in broth culture to extract the pigment. The medium was optimized using a basal medium substituted with various carbon and nitrogen sources. Temperature and pH were standardized by maintaining the cultures in required conditions. The isolated organism was found to be Streptomyces violaceoruber. YMG medium was found suitable for growth and Bottcher-Conn’s medium showed higher pigment production. Actinorhodin was extracted using NaOH/HCl system. On optimization, the best carbon sources were found to be glycerol and mannose. The most favourable nitrogen sources were peptone and sodium caesinate. The optimum temperature range was 28-30°C and optimal pH was found to be between 7.6 and 8.0.