title: Degradation of inhibitory substances in sludge by Galactomyces sp. Z3 and the role of its extracellular polymeric substances in improving bioleaching.
abstract: This study sought to elucidate the effect and mechanism of Galactomyces sp. Z3 in improving the bioleaching of heavy metals from sludge. Results showed that co-inoculation of Galactomyces sp. Z3 and two Acidithiobacillus strains (Acidithiobacillus ferrooxidans LX5 and Acidithiobacillus thiooxidans TS6) reduced the period required for sludge bioleaching by 4.5days compared to Acidithiobacillus alone. Further, removal efficiencies of Cu, Zn and oxidation rate of Fe(2+) and S(0) were higher in co-inoculation system than the Acidithiobacillus alone. Galactomyces sp. Z3 consumed the acetate, propionate, iso-butyrate, butyrate, and iso-valerate in sludge from the initial concentrations of 109.50, 28.80, 7.70, 34.30, and 18.40mg/L to 10.20, 0.61, 0.63, 19.40 and 1.30mg/L, respectively, after 12h in the co-inoculation system, significantly lower than the concentrations observed in the Acidithiobacillus alone. Meanwhile, the surfactant properties of the extracellular polymeric substances produced by the Galactomyces accelerated the rate of sulfur oxidization by A. thiooxidans.
authors: Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region, China.
authors: Jun
authors: J
authors: Zhou
authors: Guanyu
authors: G
authors: Zheng
authors: Jonathan W C
authors: JW
authors: Wong
authors: Lixiang
authors: L
authors: Zhou
mesh_terms: D000085:Acetates / Q000378:metabolism; D042763:Acidithiobacillus / Q000378:metabolism; D002087:Butyrates / Q000378:metabolism; D006723:Hong Kong; D019216:Metals, Heavy / Q000032:analysis* / Q000302:isolation & purification; D011422:Propionates / Q000378:metabolism; D004718:Saccharomycetales / Q000378:metabolism*; D012722:Sewage / Q000737:chemistry*; D014631:Valerates / Q000378:metabolism; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D000085:Acetates; D002087:Butyrates; D019216:Metals, Heavy; D011422:Propionates; D012722:Sewage; D014631:Valerates