Indian Journal of Comparative Microbiology, Immunology and Infectious Diseases

Bacterial population involved in nutrient recycling in two white legged shrimp Penaeus vannamei culture systems viz., earthen and lined ponds was studied to understand the influence of physico-chemical parameters of pond water. Among the parameters studied, pH found to be influencing physico-chemical parameters and microbial profile in lined or earthen pond. Significantly negative correlation (P<0.01) was observed between pond water pH and carbonates, nitrate-N, total ammonical nitrogen (TAN), available phosphorus (P) and available potassium (K) content of sediment. Similarly significantly negative correlation (P<0.01) was observed with total bacterial count (TBC), total presumptive vibrio count (TVC), sulphur reducing bacteria (SRB) in earthen ponds. Additionally, significant negative correlation (P<0.01) was also observed with organic carbon (OC) and available Nitrogen (N) of the pond soil. Nitrogen level of pond soil were significantly correlated (P<0.05) with pond sediment TBC, TVC and SRB and pond water Sulphur Oxidizing Bacteria (SOB). Phosphorus level of pond soil showed significantly positive correlation (P<0.01) with TBC, TVC and sediment SRB population. In both the systems, pH did not show any correlations with SOB indicating the ability of SOB to grow under wide variations of pH levels. In lined ponds, significantly positive correlation (P<0.01) was observed between TAN and nitrate as well as between TBC and TVC. It can be concluded from the study that pond water pH and levels of N, P and K in pond bottom soil can be used as a better indicators of environmental quality for estimating the deteriorating pond conditions. In addition, it can be used as management technique for managing the pond health and environmental conditions.