Bacteria adhered to particulate matter and their role in plant litter mineralization

Abstract

In the mangrove ecosystem, plant litter is the primary source of nutrients for the mangrove microbial community. Many bacteria prefer to grow attached to the plant litter using it as a substrate. Initially, the bacterium comes into contact with the substrate by means of various physicochemical forces and then makes such adhesion irreversible by binding to it with appendages and structures such as flagella, pili, fimbriae, exopolymer, holdfast, etc. Such adhesion not only ensures the supply of nutrients but also protects the microbial community. The net result is the degradation of the substrate by the adhered bacteria contributing to the recycling of organic matter and formation of detritus. Studies on the adhered bacteria from the mangrove, estuaries and coastal ecosystems indicated that halotolerant bacteria predominate and are responsible for most of the degradation as compared with the halophilic bacteria. These bacteria showed varied enzyme activities such as cellulase, amylase, tannase, lignin peroxidase and lipase including siderophore production. About 48 % of the halotolerant isolates showed multiple enzyme production indicating the potential of these isolates in the mineralization of plant litter in mangrove ecosystems.