Interrelationships between Rates of Microbial Production, Exopolymer Production, Microbial Biomass, and Sediment Stability in Biofilms of Intertidal Sediments.

摘要: The upper few millimeters of intertidal sediment supports a varied biomass microbial consortia and microphytobenthos. Many these organisms release extracellular polymers into the surrounding matrix that can result in cohesion increased stability sediment. relationship between heterotrophic autotrophic components biofilms is not well understood. A combination mesocosm field investigations were used to investigate production rate (algae bacteria), carbohydrates, biomass, conjunction with variety environmental factors. An inverse was found rates algal both laboratory mesocosms, though significant only (P < 0.001). Stability sediments increasing bacterial Positive correlations range other variables, including 0.001), colloidal-S EPS carbohydrate 0.01), EDTA water content Using data acquired, preliminary model developed predict changes stability. Chlorophyll a, content, be most important predictors intact cores incubated under conditions. Differences observed patterns surface (0-2 mm) distribution chlorophyll when expressed on dry weight or areal basis attributed effects dewatering concomitant wet bulk density. polymeric (colloidal-S EPS) component constant fraction extract, varying from 16 58%, percentage polymer decreased logarithmically as concentrations matured Changes relationships variables over period biofilm development maturation highlight difficulties their use Exopolymer more closely correlated than numbers. Rates carbon fixation considerably greater those for bacteria, suggesting algae have much potential exopolymer production. It suggested microphytobenthos secretions make contribution