The goal of this research is to determine how the diversity, distribution, and behavior of attached bacteria influences the pathway of particulate chitin degradation and the fate of chitin degradation products in a seawater environment. This research involves fundamental studies on how relationships and interactions of particle-associated bacteria influence the path by which detrital particulate organic carbon (POC) and particulate organic nitrogen (PON), as solid chitin, are degraded and the fate of the degradation products in the marine environment. The research will explore the patterns and causes of diversity within and among populations of bacteria that commonly associate with particulate organic material in the ocean. A molecular approach is proposed, not to reveal phylogenetic diversity among bacteria, but rather to explore functional diversity in terms of an important bacterial biodegradative process in the sea-the solubilization of particulate chitin. Variations in chitinase gene expression (mRNA synthesis) and chitinase activity (protein synthesis) within and among bacterial populations will be studied during bacterial cell attachment to and growth on solid chitin. The results will contribute significantly to our rudimentary understanding of the molecular, physiological and behavioral adaptations of marine bacteria as they pass from a free-living state to a particle-associated existence and back to a free-living state again. Through this micro-scale investigation of individual cells within distinguishable, mixed populations we anticipate the discovery of new microbial associations and processes that will influence the way we view microbial-mediated carbon and nitrogen flux in the water column of the ocean.