Journal of Environmental Biology

Denaturing gradient gel electrophoresis profiling of bacterial

communities composition in Arabian Sea

Author Details

Sanjay Kumar Singh

National Institute of Oceanography, Dona Paula, Goa - 403 004, India

Nagappa Ramaiah

(Corresponding author)

National Institute of Oceanography, Dona Paula, Goa - 403 004, India

e-mail: ramaiah@nio.org

Publication Data

Paper received:

20 January 2010

Revised received:

08 May 2010

Accepted:

12 May 2010

Abstract

Denaturing gradient gel electrophoresis (DGGE) was used to elucidate spatial and temporal variations in bacterial community composition (BCC) from four locations along the central west coast of India.? DNA extracts from 36 water samples collected from surface, mid-depth (~10 m) and close to bottom (~20 m) during premonsoon, postmonsoon, monsoon were analyzed by PCR for amplifying variable region of 16S rRNA gene and subsequently through DGGE. Prominent bands were excised, cloned and sequenced indicated the preponderance of gammaproteobacteria, bacteroidetes and cyanobacteria. Non-metric dimensional scaling of the DGGE gels indicated that the spatial variations in BCC were prominent among the sampling locations. Temporal variations in the BCC appear to be influenced by monsoonal processes. The canonical correspondence analyses suggest that the concentration of chlorophyll a and nitrate are two important environmental factors for both spatial and temporal variations in BCC. Chlorophyll a seems to be impart a top-down control of BCC while nitrate, the bottom-up control. Our results also suggest that BCC can vary over a small geographic distance in highly dynamic, seasonally predisposed tropical coastal waters.

Key words

Arabian sea, Bacterial community, DGGE, Spatio-temporal variations, Central west-coast of India ?

Copyright ? 2011 Triveni Enterprises. All rights reserved. No part of the Journal can be reproduced in any form without prior permission. Responsibility regarding the authenticity of the data, and the acceptability of the conclusions enforced or derived, rest completely with the author(s).