The distribution of selected organic molecules in freshwater sediment

The microbial degradation of organic material in lake sediment is dependent upon several parameters including the molecular nature of the organic material. In this study, the flux in the concentration of selected substrate molecules (cellulose, chitin and protein) was examined in sediment over a five-month period. In addition, the levels of metabolic products (free sugars, free amino acids and volatile acids) were also monitored. Results of the study indicate that while chitin and protein were actively metabolized, cellulose was less subject to degradation. The distribution of metabolic products over sample time indicated that aerobic metabolism was the primary mechanism of decomposition. Free sugars and dissolved amino acid levels always exceeded volatile acid concentrations.