Establishment of the white rot fungus Phanerochaete chrysosporium on unsterile straw in solid substrate fermentation systems intended for degradationof pesticides

The effects of different inoculum-loading rates and pre-treatment of wheat straw with formic acid and hot water (50 degreesC) on the establishment of Phanerochaete chrysosporium on unsterile straw were studied in laboratory s cale and in a 1.5-m(3) bioreactor. The establishment of P. chrysosporium on unsterile straw was satisfactory. Phanerochaete chrysosporium and other fu ngi, which developed simultaneously, were able to produce the activity nece ssary to degrade two herbicides, bentazon and MCPA (4-chloro-2-methylphenox yacetic acid) in 20 days (65 and 75%, respectively). The decrease of both h erbicides coincided with the presence of the activity of the lignin-degradi ng enzymes lignin peroxidase and manganese peroxidase/laccase. Extensive gr owth of P. chrysosporium or other lignin-degrading fungi on unsterile straw would be excellent for inexpensive solid substrate systems intended for de gradation of pesticides.