Abstract:

Three arsenic-resistant strains of fungi were isolated and identified as Chaetomiumglobosum, Alternaria tenuissima and Scheffersomyces stipitis from arsenic contaminated soils, and tested for tolerance of the strains to As and effects of the treatment of As-contaminated soils with the strains on soil As bio-availability relative to duration of the exposure to and inoculation rate of the fungi. Results show that the three strains were quite good in tolerance to As⁵⁺ in the range of 5-100 mg•L^-1 As⁵⁺ and displayed an order of Scheffersomyces stipitis > Alternaria tenuissima > Chaetomium globosum. When As concentration was in the range of 5-10 mg•L^-1, Scheffersomyces stipitis was somewhat promoted in growth. Within the first 30 days of the inoculation of the three strains, soil bio?available As increased by 137.2, 77.9 and 36.5 times, respectively, as compared with CK. Their effects on soil As varied with their inoculation rate, displaying a rising trend with the rate and a positive relationship.

Key words: arsenic tolerance, fungi, bio-available form