Peptidase Activity in River Biofilms by Product Analysis

Abstract

There have been several reports of proteolysis resulting from the activities of pelagic marine microorganisms (Hollibaugh and Azam, 1983; Hoppe, 1983; Rosso and Azam, 1987; Hoppe et al., 1988). Exoproteolytic activities of intact microbial biofilms, other than in marine (Meyer-Reil, 1987) and freshwater sediments (Jones, 1979), have received less attention, despite the suggestion that attached bacteria have disproportionately higher protein-degrading activities than free-living bacteria (Hollibaugh and Azam, 1983). Substrate analogs have been used to investigate proteolytic activities in river sediments (Sinsabaugh and Linkins, 1988) and biofilms (Jones and Lock, 1989), but methods that rely on the addition of high concentrations of substrate identify potential, rather than actual, activities.