Production of certain hydrolytic enzymes by psychrophilic bacteria from the Antarctic krill, zooplankton and seawater

Abstract

Psychrophilic bacteria isolated from krill, zooplankton and water samples collected in the Indian Ocean Sector of Southern Ocean during the Ninth India Expedition (1989-1990) were enumerated and several strains subjected to various biochemical tests. Presence of different enzymes was examined from about 500 of these strains. Bacterial numbers were the highest in the krill gut samples; moderate on zooplankton surfaces and low in water and the ice samples. Pseudomonas, Vibrio, Chromobacterium, Aeromonas, Acinetobacter and Moraxella were the genera among the Gram-negative organisms. Nearly 8% of the isolates were Gram-positive and over 15% were unidentifiable. Notably, the bacterial strains collected from zooplankton were found to possess large number of hydrolytic enzymes compared to those strains collected either from water or krill samples. Based on these results, the functional role of bacterial enzymes in relation to trophodynamics of euphausiids and their role in the post-harvest technology of krill is discussed