Nutrient Recovery from Cyanobacteria Biomasses Using Purple Nonsulfur Bacterium Rhodopseudomonas palustris

Occurrences of harmful cyanobacterial blooms are a worldwide environmental problem in most eutrophic lake ecosystems. But what should be noticed is that cyanobacteria can be used as a useful resource due to the wide range of metabolites they produce. Nutrient partitioning using purple nonsulfur bacteria (PNSB) has the potential to biologically concentrate nutrients. The present study evaluated the kinetics of nutrients released from decomposed field blue green algae (BGA) biomasses. The potential of nutrient acquisition from decomposed BGA biomasses for culturing Rhodopseudomonas palustris (R. palustris) was investigated via fed-batch experiments. Results indicated that R. palustris stimulated in algae substrates with algae biomasses ranging from 3.33 to 10 g/L. Removal efficiencies of N and P in the stationary phase of growth were at least 40% and 95%, respectively, of all the nitrogen (N) and phosphorus (P) released. Additionally, the cellular contents like total lipid and poly-beta-hydroxybutyrate (PHB), as well as the fatty acids produced by R. palustris, were consistent. Hence, practice based on the bacterial production for the nutrient recovery from BGA biomasses provides a new insight in field algae disposal. It will lower the chances of secondary pollution due to algae decay and produce giant cells of R. palustris and surely will prosper the industries applying R. palustris.