Abstract

The eastern Arabian Sea has a unique and permanent oxygen minimum zone (OMZ) that extends along the western continental margin of India. In order to understand the bacterial community structure and diversity of OMZ sediment of the Arabian Sea (AS), PCR-DGGE analysis were carried out for samples collected off Ratnagiri, Goa and Karwar at 50m, 200m, 500m and 1000m depths. PCR-DGGE analysis showed that Proteobacteria dominated all the sites ie 50m (non-OMZ) and 200m, 500m and 1000m (OMZ) along the depth gradient. Majority of the bands were attributed to the Proteobacteria. The other groups obtained belonged to Nitrospira, Bacteriodetes, Actinobacteria, Chloroflexi and Acidobacteria. The species diversity index was higher in the OMZ sites compared to the non-OMZ sites.

Keywords: Arabian sea; OMZ; Bacterial diversity; DGGE