Figure 1. Native PAGE of extracellular enzymes secreted by Trichoderma harzianum isolate Th650 cultured in the presence of cell walls of: i) F. oxysporum f. sp. lycopersici, ii) Pyrenochaeta lycopersici or iii) Rhizoctonia solani as the sole carbon source.

(a) Endochitinases. Native PAGE at pH 4.4 separated proteins (50 µg per lane) from supernatants of culture media. Endochitinase activity was visualised after incubating the polyacrylamide gel with an auxiliary 2% (w:v) agarose gel containing glycol chitin, and further incubation with 0.01% (w:v) fluorescent brightener 28. Arrows show endochitinase activity.

(b) β-1,3-glucanases. Native PAGE at pH 4.4 separated proteins (50 µg per lane) from supernatants of culture media. β-1,3-glucanase activity was visualised after incubating the gel with 1% (w:v) laminarin and developing bands of activity with 0.15% (w:v) triphenyltetrazolium. Arrows show β-1,3-glucanase activity.

(c) Proteases. Native PAGE at pH 4.4 in haemoglobin containing gels, separated proteins (50 µg per lane) from supernatants of culture media. Protease activity was visualised after incubating the gel with Coomassie blue. Clear zones on the gel indicate proteolytic activity.