Way, J. L.. State University of New York-Stony Brook, way@msrc.sunysb.edu
Scranton, M. L.. State University of New York-Stony Brook, mscranton@notes.cc.sunysb.edu
Taylor, G. T.. State University of New York-Stony Brook, gtaylor@notes.cc.sunysb.edu
Yu, Y. State University of New York-Stony Brook, yu@msrc.sunysb.edu

 
PATTERNS OF BACTERIOPLANKTONIC EXOENZYME ACTIVITY IN LOWER HUDSON RIVER AND WESTERN LONG ISLAND SOUND ESTUARIES
 
Before macromolecular organic matter is assimilated by bacteria, it must be hydrolyzed by exoenzymes into monomers. Measurement of exoenzyme activity using fluorogenic substrate analogs (MUF- and MCA-labeled substrates) provides information about which classes of organic polymers are metabolized by bacteria and about the diverse composition of organic matter pools in lower Hudson River estuary (HRE) and western Long Island Sound (WLIS. On 12 cruises between October 1996 and October 1998, hydrolytic activities of B-glucosidases, peptidases, chitinases, lipases and alkaline phosphatases were measured at four stations in WLIS and HRE. Initial results suggest that lipase and peptidase activity were most prevalent throughout the year at the WLIS station and activity patterns among the three HRE stations varied seasonally. Size fractionation experiments were also conducted to determine the relative contributions of bacteria, phytoplankton and zooplankton to measured hydrolytic activities on various substrate analogs. Data from measurements of bacterial production, primary production, chlorophyll, turnover of selected monomers and various environmental parameters will be compared to the exoenzyme activity data. Maximum hydrolysis rates are expected to correspond to times of high bacterial biomass and production, as well as to chlorophyll-a content.
 
Day: Thursday, Feb. 4
Time: Poster
Location: Sweeney Center
 
Code: SS33TH0727S