ABSTRACT
Chitin is a polymer of N-acetylglucosamine and rivals cellulose as the most abundant biopolymer in nature. It is found in the exoskeletons of all arthropods and in fungal cell walls. Chitin degradation can be measured by determining concentrations and turnover rates. Chitin concentrations in aquatic samples can be estimated by incubating particles with a labeled protein, wheat germ agglutinin that binds specifically to the N-acetylglucosamine residues that comprise chitin. Turnover rates of chitin can be measured using a substrate analog, methylumbelliferyl- N,N'-diacetyl-chitobioside. Analogs have been commonly used to measure extracellular enzyme activity in aquatic samples. Advantages of the assays include: short assay times; few steps and reagents; and the chitin concentration assay measures chitin that is not sterically hindered from degradation by chitinases and thus, is likely to be measuring chitin that is available for the degradation by heterotrophic bacteria.
