Interactions of sulfur and methane-oxidizing bacteria in tropical estuarine sediments

The bacterial oxidation of sulfur and methane is central to the biogeochemical processes in sediments such as the tropical mangrove sediments. However, there is a lacuna of information on the seasonal interactions including the influence of monsoons which is a major driver of seasonal change, on sulfur-oxidizing bacteria (SOB) and methane-oxidizing bacteria (MOB), their activity and the environmental variables. To understand these interactions, the analysis was carried out on sediment samples that were sampled monthly for a year from Chorao mangrove, Goa, southwest coast of India. SOB (3.8×10 5 CFU g −1 ) and MOB (0.90×10 5 CFU g −1 ) had maximum average abundance in the surface sediments in the post-monsoon and monsoon season, respectively. The mean sulfur-oxidation activity (SOA) of 2.63 mM day −1 and methane-oxidation activity (MOA) of 110.94 mM day −1 were highest in surface sediments during the post-monsoon season. Generally, the activity of SOB and MOB in surface sediments of post-monsoon was 2.2 times(×) and 2.8× respectively higher than that in the monsoon season. Among the environmental parameters analyzed, protein and sulfide concentrations significantly ( p