A range of experiments was performed to establish optimum aeration and moisture content conditions for sporulation of Metarhizium anisopliae IMI330189 in solid substrate fermentation (SSF). The cultivation was performed in column bioreactors. The following conclusions from the experimental results obtained have been made: (1) Forced aertion is not crucial for sporulation of M. anisopliae IMI3301 89 (no increase in sporulation has been achieved with increase in aeration). (2) Changes in moisture content affect sporulation, the optimum being at 57-58% moisture content. (3) No interaction between the two factors studied was observed. (C) 2004 Elsevier Ltd. All rights reserved.