Ergosterol content as a measure of biomass of potential biological control fungi in liquid cultures

Abstract

784A and G. solani 810A exhibited the highest and lowest levels of ergosterol, respectively, under test conditions. Based upon relative amounts of ergosterol produced per mycelial dry weight, three groups namely high (G. roseum 784A), medium (Mariannaea elegans 386E, G. roseum 321M, G. viride 623E, G. virens 258C and G. virens 258D) and low (Trichoderma pseudokoningii 228B, G. solani 810A) were identified. Concentration of ergosterol do not always correlate with absolute fungal biomass and is influenced by both internal and external factors. Test growth conditions should therefore closely mimic that of anticipated environment. Concentrations of ergosterol of eight biological control fungi reported in this study fall within the range of other fungi reported in the literature. Under control conditions, ergosterol concentration of the eight potential biological control fungi may be used as a relative index of their biomass and their growth in liquid cultures.