PRINCIPAL 



INVESTIGATOR(S) David L. Kirchman 



College of Marine Studies 

 University of Delaware 

 Lewes, DE 19958 



PROJECT TITLE DEGRADATION OF PARTICULATE ORGANIC MATTER IN 



COASTAL OCEANS: THE CHITINASE SYSTEM AT A 

 MOLECULAR LEVEL 



AMOUNT OF FUNDING FY 1994: $99 K 



SUMMARY OF GOALS 



The overall goal is to estimate concentrations and degradation rates of chitin in the water 

 column of coastal oceans and to examine the contribution of chitin to the carbon and nitrogen 

 budget of heterotrophic bacteria. Chitin is produced by many marine organisms and is thought 

 to be abundant, although there are few direct measurements. In addition to being important per 

 se, chitin may prove to be a good model substrate for understanding degradation of particulate 

 organic matter by bacteria. 



We can attack this question nearly immediately with methods already developed. Our 

 immediate goal is to test these methods in controlled experiments. These methods include 

 published procedures for measuring chitin concentrations and turnover rates. We need to see if 

 we can put these methods together and show that we can truly measure chitin degradation. 



Another goal of the proposed work is to develop molecular approaches for examining 

 chitin degradation. The first step in this work is to obtain more information about 

 naturally-occurring chitinases (the enzyme mainly responsible for the hydrolysis of chitin). We 

 intend to isolate these chitinase genes, sequence them, and use this sequence information to 

 synthesize PCR primers. These primers will be used then to assay chitinase gene amounts in 

 coastal waters. The sequence information alone will be valuable because few chitinases have 

 been sequenced and none from "natural" bacteria. Our first goal is to see, within an order of 

 magnitude, if chitinase gene amounts correlate with chitin concentrations and degradation rates. 



SPATIAL AND TEMPORAL SAMPLING SCALES 



We can collect samples about every 5 km or every 4 hours. 



59 



