Depth profile exploration of enzyme activity and culturable microbial community from the oxygen-starved soil of Sundarban mangrove forest, India

Abstract

Populations of culturable microbes and active-ties of dehydrogenase & β-D glucosidase were found maximum in surface soil and decreased with increase in depth in Sundarban mangrove environment. The maximum (13.529 × 10 6 C.F.U g –1 dry weight of soil) and minimum (11.547 × 10 6 C.F.U g –1 dry weight of soil) total microbial po-pulations in surface soil were recorded during post-monsoon and monsoon respectively. At 60 cm depth, the minimum (6.396 × 10 6 C.F.U g –1 dry weight of soil) and maximum (8.003 × 10 6 C.F.U g –1 dry weight of soil) numbers of total microbial populations were observed during mon-soon and post-monsoon respectively. A decrea-sing trend of total microbial load, enzyme activi-ties and nutrient status with organic carbon were found with increase in depth throughout the year. Present study revealed the relationship among depth integrated variations of physico-chemical components (viz. soil temperature, pH, moisture, organic-C, Nitrate-Nitrogen, and available-P) and microbial populations as well as activity of de-hydrogenase and -D glucosidase enzymes.