Influence of sediment chemistry on mangrove-phosphobacterial relationship

The study reveals importance of sediment chemistry in mangrove-phosphobacterial relationship. The various physicochemical parameters of sediment, bacterial distribution, and acidic- alkaline phosphatase activity were studied in Avicennia marina mangrove sediments. The sampling sites were four mangrove forests along West India. Rhizospheric, pneumatophoric and bulk/non-rhizospheric sediment were collected. The rhizospheric sediment showed higher bacterial activity. The pH was observed low in the rhizospheric sediment and good abundance of phosphate-solubilizing bacteria (PSB). This was also supported by other physico-chemical parameters. Acid phosphatase activity was found to be higher in rhizospheric sediment indicating acid production at rhizosphere by microbial action and root exudation. It is the first study indicating that alkaline phosphatase activity was observed to be higher in pneumatophoric sediment. This coincides with higher number of phosphatase-producing bacteria (PPB) and high inorganic P in the pneumatophoric sediment, revealing that this region of A. marina harbours favourably more PPB with utilization of organic P by bacterial load and conversion to inorganic forms stressing that strong bonding exists between mangrove-sediment-phosphobacterial relationships.