Degradation of inhibitory substances in sludge by Galactomyces sp. Z3 and the role of its extracellular polymeric substances in improving bioleaching

► Galactomyces sp. Z3 eliminated organic acids based inhibition on Acidithiobacilli. ► Co-inoculation of Galactomyces reduced the bioleaching time by 4.5 days. ► Surfactant property of the EPS produced by Galactomyces sp. Z3 was demonstrated. ► Galactomyces EPS accelerated the rate of sulfur oxidization by Acidithiobacillus thiooxidans.