Each isolate was cultured
in glucose peptone broth (GPB), with or without 1.25 % L-tryptophan, at 25 C for 7 d, under shaking at 250 rev/min. Only
eight out of 24 isolates were shown to produce IAA in the medium with and without L-tryptophan. Xin et al. (2009) characterised three IAA-producing endophytic yeasts (WP1, PTD2
and PTD3) from the Populus tree and found the highest IAA
production (39 mg gÀ1 dry cell) in the isolate WP1, whereas
the isolates PTD2 and PTD3 produced 18 and 8 mg gÀ1 dry
cell of IAA, respectively