Prevalence of obligate and facultative anaerobic bacteria in the mudbank along the southwest coast of India

Abstract

Mudbanks along the southwest coast of India are exposed to upwelled hypoxic waters and higher concentrations of methane during summer-monsoon.We report the phylogenetic composition of obligate and facultative anaerobic bacteria isolated from Alappuzha mudbank and their abilities to adapt to hypoxia. The average anaerobic bacterial abundances in the water column and sediment were in the range of 1.5 � 10 3 to 2.0 � 10 5cfu ml ?1 and 1.3 � 10 4 to 2.0 � 10 6cfu g ?1 respectively. Most of the bacteria isolated from Alappuzha mudbank were facultative anaerobes and were represented by Proteobacteria (61 %), Firmicutes (21 %), Actinobacteria (8 %), and Bacteroidetes (4 %). These facultative anaerobes were able to alter their fatty acid profile in response to aerobic and anaerobic culture conditions. In short, the field observations and laboratory experiments showed the response of a bacterial community towards changing environmental conditions in a persistent mudbank along the southwest coast of India Further studies are ongoing to understand the cellular and molecular basis of these adaptations and the implications for organic matter remineralization.