Microorganisms from composting leaves: Ability to produce extracellular degradative enzymes.

Mixed populations of bacteria, fungi, and actinomycetes in a leaf compost pile were examined over a 100-day test period for their ability to produce extracellular proteolytic, lipolytic, amylolytic, cellulolytic, pectolytic, and ureolytic enzymes and ability to utilize alkanes. Urea was added to the leaves to adjust the carbon to nitrogen ratio but was of little value in maintaining the proper ratio since it was degraded within the first few days. The degradative enzymes excreted by microorganisms was dependent on the temperature of the pile. In many cases organisms able to produce specific extracellular enzymes at medium temperatures were able to grow at high temperatures, but either did not excrete the specific enzymes or the enzymes were inactivated by the high temperature.