Ectoenzymes synthesis

Enzyme research in wetland ecosystems is not as extensively reported as it is for uplands and other aquatic ecosystems. On the basis of the results of various experiments under laboratory and field conditions, Chrost (1991) proposed a conceptual model for the role of microbial ectoenzyme synthesis, control, and activity in aquatic enviromnents. The following general conclusions are drawn on the interaction of algae and microbial communities in transforming HMW-OM into readily utilizable LMW-OM (Eigure 5.23) ... 

Many of the proteins of membranes are enzymes. For example, the entire electron transport system of mitochondria (Chapter 18) is embedded in membranes and a number of highly lipid-soluble enzymes have been isolated. Examples are phosphatidylseiine decarboxylase, which converts phosphatidylserine to phosphatidylethanolamine in biosynthesis of the latter, and isoprenoid alcohol phosphokinase, which participates in bacterial cell wall synthesis (Chapter 20). A number of ectoenzymes are present predominantly on the outsides of cell membranes.329 Enzymes such as phospholipases (Chapter 12), which are present on membrane surfaces, often are relatively inactive when removed from the lipid environment but are active in the presence of phospholipid bilay-ers.330 33 The distribution of lipid chain lengths as well as the cholesterol content of the membrane can affect enzymatic activities.332... 

Chrdst, R. J. (1991). Environmental control of the synthesis and activity of aquatic microbial ectoenzymes, In Microbial Enzymes in Aquatic Environments, Chrdst, R. J., ed., Springer-Verlag, New York, pp. 29-59. 

Low concentration of LM W-OM and high concentration of polymeric HMW-OM (substrate for ectoenzymes) can derepress and induce enzyme synthesis in heterotrophic bacteria. 

Chrost, R. J. 1991. Environmental control of the synthesis and activity of aquatic microbial ectoenzymes. In R. 

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