Bacterial degradation of strobilurin fungicides: a role for a promiscuous methyl esterase activity of the subtilisin proteases?

Strobilurin fungicides are some of the most heavily used antifungal chemicals in agriculture. However, little is known of their fate in the environment. We have identified bacteria that slowly transform strobilurin fungicides via hydrolysis of a methyl ester group in the toxophore, rendering them non-fungicidal. A carboxypeptidase (subtilisin Carlsberg) was found to have this activity, albeit with low specific activity (2.4 × 10-2 nmol s-1 mg-1), and to possess specificity towards an analog of the fungicidal isomer of commercial strobilurins. Substrate-docking studies using the known structure for subtilisin Carlsberg revealed a plausible explanation for both the activity and isomer specificity of this class of hydrolase. These findings suggest that the promiscuous strobilurin methyl esterase activity of the subtilisin-like carboxypeptidases may have a role in the environmental fate of the strobilurin fungicides

Growing winter malting barley west of the Cascades

Growing malting barley is increasingly being considered by farmers west of the Cascades to serve emerging craft brewing and distilling markets and to function as a rotation crop for horticultural crops, such as potatoes or vegetable and grass seed. Several publications provide information on growing barley generally and the prospects for a malting barley industry in the region. This publication provides a succinct resource for those preparing to grow winter malting barley