Aspergillus nigerand aPenicilliumsp. are not directly involved in the degradation of chlorsulfuron

摘要

AbstractWhenAspergillus nigeror aPenicilliumsp. were grown in potato dextrose broth supplemented with chlorsulfuron, the herbicide concentration decreased by 97–99 within 78–96 h and the pH of the medium fell from 7.2 to between 2.4 and 3.1. If, during growth, the pH was maintained at or near neutrality, no decrease in herbicide concentration occurred. When sterile medium containing the herbicide was titrated with acid to mimic acid formation during fungal growth, the herbicide concentration again declined. Precipitation was not responsible for the observed decrease. The data indicate that, in laboratory media, these fungi do not directly metabolise the herbicide as previously thought. Chlorsulfuron degradation in perfused soil cores was not enhanced by inoculation withA. niger. Our results show thatA. nigerand aPenicilliumsp. do not degrade chlorsulfu