This in an award to provide support for research on a modification to a suspended growth biological process used for treatment of wastewater to enhance its ability to reduce the phosphorus content of the process effluent. The objective of this project is to elucidate the mechanism of the enhancement process. This is planned to be accomplished by isolation of pure cultures of organisms that have been identified as capable of the enhancement process, study of their growth characteristics, metabolism and genetic control. The procedures to be used in this project include enrichment techniques for isolation of the organisms from suspended growth reactors exhibiting significant phosphorus removal, verification of their ability to enhance phosphorus removal in pure culture and determination of their growth characteristics, metabolism and genetic control. Specific objectives include determination of growth characteristics of isolated organisms and their ability to shift from completely aerobic conditions to aerobic/anaerobic cycling and back to completely aerobic culture conditions. The investigators plan to determine the influence of phosphorus, carbon substrates and anaerobic shifts on gene expression, the interactions between an energized cell membrane and transport of phosphorus and acetate, and the importance of intracellular storage materials. The project is expected to provide a better understanding than now exists of the fundamental microbial mechanisms involved in enhanced biological phosphorus removal by suspended growth biological reactors. This improved understanding is expected to improve the engineering design of suspended growth biological reactors used for treatment of wastewaters that contain phosphorus including adequate control to improve the efficiency with which they meet their design objectives.***
