The compost and test specimens were incubated in 4-L
(working volume) vessels (length 30 cm and diameter 15 cm),
made of PVC pipe placed in a 55 C incubator (BioCold Environmental
Inc., MO, U.S.). Each vessel contained approximately 1100 g
of material on a wet-weight basis. The reactors were aerated from
below at 100 1 ml/min to maintain aerobic conditions. To avoid
drying during the experiment, air was saturated by bubbling