INDUCTION OF TREHALOSE IN SPORES OF THE BIOCONTROL AGENT TRICHODERMA-HARZIANUM

Spores of the biocontrol agent Trichoderma harzianum P1 produced in li quid media and harvested in the stationary sporulation stage SSS (afte r 60 h), had higher viability after slow (>4x) and fast drying (>12x) than their counterparts harvested in the exponential sporulation stage , ESS (after 30 h). The trehalose content of SSS spores was almost 20x higher than that of ESS spores (0.16 vs. 3.4 mg/100 mg, respectively) . Heat shock (40 degrees C x 90 min) effectively increased the trehalo se content 2.5x with respect to untreated SSS spores. The trehalose co ntent achieved in heat-treated SSS spores was almost 60% higher than t he maximum reached by holding the spores under water-stress at 97% rel ative humidity prior to drying.