Microbiome signatures of mangroves and salt marsh halophyte rhizosphere soil sediments: a metagenomic approach

In this research, the rhizosphere soil microbiome diversity of mangrove trees such as Avicennia marina, Ceriops tagal & Rhizophora apiculata and salt marsh halophytes Suaeda maritima, Suaeda monoica and Sesuvium portulacastrum from Karankadu mangroves of Tamil Nadu, India was investigated. The collected sample was profiled by 16S rRNA Illumina NovaSeq 6000 platform sequencing of V3–V4 amplicon region by metagenomic approach to investigate the bacterial communities related with the different mangrove species. Root-associated microbes of the mangrove trees play important roles in protecting and maintaining mangrove ecosystems. Bacteria were the most abundant domain followed by Archaea and Eukaryota; Proteobacteria, Actinobacteria, Firmicutes, Fibrobacterota, Chlorobiota, and Bacteroidota were found to be predominant phyla present in all samples; Unculturable environmental microbes were also detected, particularly abundant in S. maritima and S. monoica samples. Staphylococcus aureus, Vibrio parahaemolyticus, Klebsiella pneumoniae, Salmonella enterica, Streptomyces griseocarneus were the most abundant species observed in this study. The variations in bacterial community structure across these ecosystems may be influenced by the distinct environmental conditions of each sampled mangrove habitat. For the first time, our findings highlight the richness of microbial diversity in the Karankadu mangroves, providing essential baseline data and revealing differences between mangrove trees and halophytes. This study offers valuable insights for further investigation into the mechanisms governing rhizosphere microbiome interactions with their host environment.