Pollution and Environmental Stressors Modulate the Microbiome in Estuarine Mangroves:A Metagenome Analysis

The microbial communities of mangroves which form important links in elemental cycling and bioremediation have not been elucidated in most parts of the world. Due to urbanization and deforestation mangroves are also under threat. In the present study, high throughput next generation sequencing technology, based on 16S rRNA amplicon analysis using Illumina platform, was employed to unravel the microbial diversity present in different mangrove areas in the west coast of India. It could be seen that in mangroves, Proteobacteria and Bacteroidetes were most common, followed by taxon such as Firmicutes, Spirochaetes, Chloroflexi and Verrucomicrobia. In proteobacteria group, Gammaproteobacteria, Alphaproteobacteria and Deltaproteobacteria were most abundant. Interestingly, bacteria having the capacity to utilize sulphate were present along with methanogens in all samples, suggesting that anaerobic and sulphur- based metabolic pathways play an important role in these mangrove ecosystems. The differences in bacterial diversity can be partly attributed to biotic and abiotic factors such as physico-chemical characteristics of the samples, geographical location and natural and human-induced changes in the locality. The metagenomics analysis of mangrove sediment samples has helped in elucidating the baseline data on bacterial diversity along mangroves in Maharashtra along the west coast of India and can provide pointers for effective measures of conservation.