Detection, Screening and Molecular Characterization of Potential Actinobacterium from Lime-dwelling Powder for Extra Cellular Cellulase

Actinobacteria, conventionally known as actinomycetes are the most unique microorganisms revealing a link between bacteria and fungi. They are highly adaptable to extreme environmental condition and also exhibit a high diversity in metabolic activities. Biochemical, physiological and genetic features are mainly responsible for their higher adoptability to harsh conditions and extra cellular synthesis of wider secondary metabolites in general and enzymes and antibiotics in particular. The limestone quarry and lime powder dwellings are the harsh habitats prevailing in the northern region of Karnataka. These are the typical habitats left behind after the exploration of limestone and lime powder for highly commercial industrial activities such as production of cement and petroleum refining process respectively. In the present investigation, efforts were made to detect cellulolytic actinobacteria from lime powder dwellings. Actinobacteria confirmed by the basic colony characters, microscopic features, biochemical and physiological properties were screened for the potential cellulolytic activity. In all 54 isolates of actinobacteria were detected and screened to obtain three best cellulolytic actinobacteria, namely DSA22, DSA38 and DSA39. The maximum zone of hydrolysis on carboxymethylcellulose medium was an important criterion to screen the best cellulolytic isolates of actinobacteria. Further, the three best isolates of cellulolytic actinobacteria were screened for maximum production of extra cellular cellulase. The isolate DSA22 with higher enzyme activity (12 IU) was subjected to molecular characterization. Based on 16s rRNA analysis (BioEra Laboratory, Pune, Maharashtra) an isolate DSA 22 was identified as Streptomyces enissocaesiles.