title: Biosorption of organochlorine pesticides using fungal biomass.
abstract: Cladosporium strain AJR(3)18501 was tested for its ability to sorb the organochlorine pesticide (OCP) p,p'-DDT from aqueous media. When p,p'-DDT was added to distilled water, ethanol or 1-propanol solutions in excess of its solubility, p,p'-DDT was sorbed onto the fungal biomass. Increasing the amount of p,p'-DDT in solution by changing the medium composition increased sorbent uptake: p,p'-DDT uptake by the fungal biomass was 2.5 times greater in 25% 1-propanol (17 mg of p,p'-DDT g(-1) dry weight fungal biomass) than in distilled water. When p,p'-DDT was dissolved in 25% 1-propanol (12 mg x l(-1)), rapid p,p'-DDT sorption occurred during the first 60 min of incubation. p,p'-DDT in solution was reduced to 2.5 mg x l(-1) with the remaining p,p'-DDT recovered from the fungal biomass. A number of environmental parameters were tested to determine their effect on p,p'-DDT biosorption. As arsenic (As) is prevalent at DDT-contaminated cattle dip sites, its effect on p,p'-DDT uptake was determined. The presence of As [As(III) or As(V) up to 50 mg x l(-1)] did not inhibit p,p'-DDT uptake and neither As species could be sorbed by the fungal biomass. Changing the pH of the medium from pH 3 to 10 had a small effect on p,p'-DDT sorption at low pH indicating that an ion exchange process is not the major mechanism for p,p'-DDT sorption. Other mechanisms such as Van der Waals forces, chemical binding, hydrogen bonding or ligand exchange may be involved in p,p'-DDT uptake by Cladosporium strain AJR(3)18501.
mesh_terms: D000433:1-Propanol / Q000378:metabolism; D000042:Absorption; D001151:Arsenic / Q000378:metabolism; D001673:Biodegradation, Environmental; D018533:Biomass; D002963:Cladosporium / Q000378:metabolism* / Q000648:ultrastructure; D003634:DDT / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007306:Insecticides / Q000378:metabolism*; D012989:Soil Pollutants / Q000378:metabolism; D014867:Water / Q000378:metabolism
chemical_list: D007306:Insecticides; D012989:Soil Pollutants; D014867:Water; D000431:Ethanol; D000433:1-Propanol; D003634:DDT; D001151:Arsenic