Regulation of Attached Bacterial Growth by Adsorbed Proteins

摘要

The general objective of this project was to examine one component of the primarybiofilm, protein, which has been hypothesized to be a major component of both dissolved and adsorbed organic pools in seawater. In previous work we found that surface energy was important in determining adsorption of protein to surfaces in seawater and degradation rates by bacteria and bacterial growth. In the last phase of this work, we examined the chemical nature of actual protein in seawater using HPLC techniques which we developed, standard chemical assays, and bioassays. We showed that protein in seawater is not the same chemically as cellular protein. Bacteria appear to treat nearly all seawater protein as if it were glycolated and degrade it at much lower rates than unmodified, fresh protein. Other experiments showed that cellular protein introduced into seawater is quickly modified by abiotic reactions and becomes less easily hydrolyzed by bacterial proteases within hours. The abiotic reactions appear to include adsorption to small colloids. These results begin to explain the growth dynamics of microorganisms on surfaces and the origin of refractory organic matter which is highly abundant in seawater.... Biofouling, Protein adsorption, Biofilm, Attached bacteria.