Density of heterotrophic bacteria in Meghadri mangrove ecosystem, Visakhapatnam, east coast of India

The density of heterotrophic bacteria was investigated from the sediments of Meghadri mangrove ecosystem of Visakhapatnam from April 2006 to March 2007. The sediments harboured the bacterial genera Bacillus, Pseudomonas, Brevibacterium, Staphylococcus and Micrococcus. The mean density of total heterotrophic bacteria was 7.93 x 10³cfu.g ¹. Among the proteolytic, glycolytic and lipolytic bacterial densities, the lipolytic bacteria (5.31 x 10³ cfu.g ¹) were found higher than the other bacteria. The mean values of temperature, salinity, pH, dissolved oxygen and sedimentary organic matter during the study period were 29.0°C, 33.1 ppt, 7.5, 2.27 mg/ml and 2.13% respectively. The density of bacteria in the mangrove sediments is discussed in relation to the physico-chemical parameters.