SCREENING OF MARINE SOILS FROM BAY OF BENGAL NEAR CHIRALA COAST OF ANDHRA PRADESH FOR ISOLATION OF LIPOLYTIC ACTINOBACTERIA AND CHARACTERIZATION OF THE MOST POTENT ISOLATES

摘要

Three marine soil samples collected at various seashores of the Bay of Bengal near Chirala Coast of Andhra Pradesh were screened for the isolation of lipolytic Actinobacteria by tributyrin agar clearing method. The isolates were cultured under submerged fermentation conditions and assayed for their extra cellular lipase producing capabilities using olive oil as substrate. Enzyme profiling of the selected strain was done by incorporating the respective substrates in the media. The different parameters namely, morphological, biochemical, physiological and molecular were used for the characterization and identification of actinomycetes isolates. The secondary structure and restriction site of selected actinomycetes were predicted using bioinformatics tools available online. Results indicated that all the isolates showed lipolytic activity after primary screening. These isolates were subjected to secondary screening and lipase activity is estimated quantitatively. Morphological, cultural, physiological and biochemical characteristics as well as enzymatic activities suggested that all the isolates belonging to the genus Streptomycetes. The marine isolate RPBS-A4 was the most active one and thus was selected further identification. The 16S rDNA amplification for phylogenetic study revealed that the isolate was highly related to Streptomyces fungicidicus (~97%), so it is designated as Streptomyces fungicidicus RPBS-A4. The RNA secondary structure showed that the free energy of the structure is -124.0 kcal/mol. Threshold energy is -4.0 with cluster factor 2, conserved factor 2 and compensated factor 4 and conservativity is 0.8. It showed restriction sites for 50 enzymes, GC and AT content of 61 and 39%, respectively.