Comparison of bacterial diversity from two mangrove ecosystems from India through metagenomic sequencing

In the present study, we explored the microbial diversity of two mangrove regions, Mangalavanam (MAN) and Puthuvype (PVY), in Cochin, India. While PVY is a coastal island, MAN lies in the heart of the mainland of Cochin, making these two ecosystems different. Illumina MiSeq metagenomic analysis using V3–V4 region of 16S rRNA gene was employed to study the microbial diversity. Based on the sequence analysis, the most abundant prokaryotic domain was bacteria (99.94% and 99.87% in sample PVY and MAN, respectively). Proteobacteria was the most dominant phylum in both MAN (48.19%) and PVY (65.66%). Alphaproteobacteria (18.27 %) was the most abundant class found in MAN, whereas Gammaproteobacteria (43.94%) was dominant in PVY. Principal component analysis was used to determine factors that modulate the bacterial community structure. In both environments, bacterial communities showed significant variation due to variation in sediment composition and location. At the phylum level, both sampling sites showed similarities but minor communities and species showed distinct variations in the distribution. The observed differences in the bacterial community structure in these ecosystems could be attributed to the specific environmental characteristics of each sampled mangrove ecosystem.