Biosorption of cadmium by a metal-resistant filamentous fungus isolated from chicken manure compost

A fungus, XJ-1, isolated from chicken manure compost was phylogenetically related to Penicillium chrysogenum. The minimum inhibitory concentrations of the fungus for Cd2+, Cu2+, Cr3+, Cr6+, Co2+ and Zn2+ were 300, 85, 55, 8, 25 and 70mM on plates and 200, 65, 30, 2, 30 and 48mM in liquid media, respectively. Biosorption of Cd2+ by XJ-1 was investigated as a function of initial pH, contact time, biomass loading and Cd+ concentration. According to the Langmuir isotherm, the maximum adsorption of Cd2+ was 100.41 mg g(-1) dry biomass. Analyses using FTIR, SEM and XPS showed that the functional groups -OH and -C=O on the XJ-1 cell wall are the dominant binding sites for Cd2+. The results indicate that XJ-1 biomass is an efficient biosorbent for Cd2+ and has great potential for the in situ remediation of environments contaminated with heavy metals.