The participation of vacuoles and the regulation of various metabolic pathways under acid stress promote the differentiation of chlamydospore in Trichoderma harzianum T4.

The sporulation type of T. harzianum T4 can be controlled by adjusting the fermentation pH. T. harzianum T4 cells employ various self-protection measures against strong acid stress, including regulating their metabolism to produce a large number of chlamydospores for survival.