B. Vishnupriya

A total of fifty six actinomycete isolates were isolated from the ten marine sediments of south India. Marine environment is a potential source of novel actinomycetes, which are a potent source of antibiotics and novel bioactive compounds. The isolates were identified as actinomycetes by morphological, biochemical and microscopic studies. The isolated actinomycetes were screened for L-asparaginase activity by rapid plate assay method. Based on screening, isolate 1, 2 and 18 were showed large clear pink zone and its diameter (dm) was measured as 9.0, 8.5 and 8.5 cm and the enzyme production has been determined by nesslerization method. The spectrophotometric assay of enzyme activity of the isolates 1, 2 and 18 were found to be 1.92, 1.48 and 1.46 U/ml.

Marine Streptomyces sp.T1027 obtained from South coast of India was discovered to produce and accumulate β-carotene under the influence of light in liquid shake flask culture. The accumulation of β-carotene was growth associated and controlled by light, aeration, carbon and substrate solubility. Starch was the ideal substrate for maximum growth (4.5-6.1 g l-1) and β-carotene accumulation (92-130 μg g-1). Rapid extraction was done in Dimethylsulphoxide, Methanol (1:1) Solvent mixture. The organism was sensitive to a variety of antibiotics; in turn it was able to inhibit the human pathogen Corynebacterium diphtheria. Commercial substrates with high soluble starch content were found to produce maximum biomass and β-carotene production.