Bioprospecting for culturable psychrotrophic bacteria with extracellular hydrolytic enzymes activity from arctic lake sediments

Abstract

The ability of cold-adapted microorganisms to produce cold-active enzymes with potential biotechnological applications has recently attracted the attention of scientific community in terms of bioprospecting. This research aimed at assessing the presence and diversity of culturable psychrotrophic bacteria with hydrolytic enzymes activity and their identification using molecular approach. A total of six (6) different Arctic lake sediments were analysed. Mean viable bacterial count ranged from 2.88X103 to 5.07X105 cfu/g. A total of thirty seven (37) bacterial strains were successfully isolated at 20°C and screened for Amylase, Protease and Lipase activity. Molecular characterization using 16S rRNA gene sequence homology revealed that the isolated bacteria belong to seven genera comprising Pseudomonas, Bacillus, Dermacoccus, Arthrobacter, Janthinobacterium, Paenibacillus and Chryseobacterium. Eighteen (18) isolates; representing 49% were found to be positive to at least one of the three enzymes activity tested. Two different strains of Pseudomonas sp. (isolates 16D4 and 17D4) were found to be the most potent protease and lipase producing isolates respectively. XIA12 identified as Bacillus cereus was found to be the most potent amylase producing bacteria. Study of the growth temperature of the isolated bacteria revealed that most of isolates could grow at temperature above 20°C signifying that the isolates are true psychrotrophs. The findings of this work have confirmed that Arctic environment can serve as an ideal area for biotechnological exploration.