Environmental Technology

Bioactive pigment from soil bacteria

003A purple-blue bioactive ‘pigment producing bacteria’ was isolated from the sediments of clay mine pit lake in the district of Thiurvananthapuram. The bacterium was identified as Chromobacterium sp. (strain-NIIST CKK1) (GenBank no. FJ982784) through polyphasic approach and the culture was submitted to IMTECH (MTCC 5522) and NCL (NCIM 5341). Preliminary screening indicated the crude pigment contain the bioactive compound violacein and its derivative (oxyviolacein/deoxyviolacein). Violacein is reported to have cytotoxic (anticancer), antioxidant, antibacterial, antiviral and antifungal properties. The culture produced 0.6-1.0 g pigment/g dry biomass/d in normal growth heterotrophic growth media under aerobic conditions. The crude photosensitive pigment obtained in the study was found to be stable up to 80 ?C and at pH in the range of 2-8. Laboratory batch experiments were conducted to develop a bioprocess for preparing the pigment and a patent was submitted based on process using the specific culture. Studies are in progress for separating and purifying different compounds in the crude pigment, identifying various compounds and developing potential novel compounds from parent compounds through semi synthetic approach.

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