Investigation of Trichoderma micropropagule production as a biocontrol agent in solid state and static culture bioreactor conditions

In this study, optimization of micropropagule production conditions was studied for solid state fermentation in both horizontal drum bioreactor and tray bioreactor with wheat bran - malt lawn mixture (3:2 (w/w)) as substrate for Trichoderma harzianum EGE-K38 strain that was isolated and developed in Industrial Microbiology Laboratory at Ege University, Department of Bioengineering. Moreover, optimization of micropropagule production conditions for static culture was achieved by Modified Czapec Medium(MCM) containing 8 g/L glucose in tray bioreactor. During optimization studies for solid state fermentation, moisture content of solid substrate, fermentation temperature, air flow rate, inoculum spore concentration, inoculation volume, substrate bed thickness, the effect of using spores or mycelia containing agar pieces as inoculum, pressure pulsation and the effect of bioreactor sterilization before fermentation, for static culture, fermentation temperature, air flow rate, the effect of using spores or mycelia containing agar pieces as inoculum, inoculum spore concentration, inoculation volume, volume of liquid medium, pressure pulsation and the effect of bioreactor sterilization before fermentation were determined individually. In solid state fermentation the highest micropropagule number was achieved by horizontal drum bioreactor and tray bioreactor as 1.1±0.1×109 cfu/mL and 3.0±0.6×109 cfu/mL respectively. However, in static culture fermentation it was found as 5.2±0.2×109 cfu/mL by tray bioreactor. In the study, consecutive drying processes at different temperature values were carried out by tray bioreactor at the end of fermentations and the highest drying yield achieved after drying of solid state fermentation media was 40.0 % and after drying of micropropagules produced by static culture was 23.3 % respectively. Keywords: Biocontrol, Trichoderma, optimization, solid state and static culture fermentation, tray and horizontal drum bioreactor