ABSTRACT
Microbial enzymes and their activities have been studied primarily in pure liquid cultures under laboratory conditions. However, in natural environments microorganisms grow at interfaces as attached (sessile) mixed communities rather than as suspended planktonic populations (1). Studies of microbial enzymes in soil go some way to recognizing this, but data interpretation has often been difficult because the methodologies do not easily differentiate between enzymes associated with surface-attached populations and those loosely attached or free in the liquid phase. It is the aim of this chapter to discuss the biological characteristics of these sessile microbial populations with particular reference to their enzyme activities.
