Ecophysiology of Nitrifying and Denitrifying Microbial Communities and their Interactions in Microbial Flocs

North Carolina State University, Raleigh NC

Investigators

Abstract

0348392 de los Reyes Microbial flocs are complex microbial communities that are of fundamental importance to a wide variety of natural processes and engineered applications. The ecophysiology of microorganisms in floc microenvironments ultimately determines which organisms are present, active, and dominant under specific conditions. The research described in this proposal will apply a multidisciplinary approach to characterize the factors that control community structure and function in nitrogen-transforming flocs. The specific objectives of the project are: (1) To determine the effect of microscopic floc structure (size and shape) on rates and diversity of microbial activities and to establish the diversity, the relative numbers and spatial arrangement of microorganisms involved in nitrogen removal within flocs; (2) To determine the impact of bioreactor macro conditions (DO, substrate type and loading) on floc size, shape, and function; (3) To characterize the carbon- and nitrogen-based metabolic interactions among ammonia-oxidizing, nitrite-oxidizing, and denitrifying bacteria within a floc; and (4) To develop a macroscale model of nitrogen and carbon removal in activated sludge that incorporates microscale processes in flocs.