Micromycete Responses to Acetone: Electrochemical Express Evaluation of Acetone Metabolism

The biosensor method has not yet been applied to study the fungus-acetone interaction. The first electrochemical (amperometric) study of Fusarium oxysporum f. sp. vasinfectum cells' responses to acetone was performed to evaluate the initial stages of the metabolism of acetone in the cells of the micromycete. Using a laboratory model of a membrane microbial sensor based on the micromycete cells, it was found that the fungus had constitutive enzyme systems that were involved in acetone transport into fungal cells. The research showed that uninduced by acetone cells had degradative activity against acetone. A positive cooperativity of acetone binding with enzymes initiating acetone degradation was revealed. Oxygen concentration affected the activation of cell enzymes initiating acetone degradation, but the cells' activity in the presence of acetone maintained even at low oxygen concentration. Kinetic parameters (the maximum rate of the cells' response to substrate and the half-saturation constant) of the processes causing the fungal cells' response to acetone were calculated. The results demonstrated the convenience of the biosensor method for assessing the potential of the micromycete as a substrate-degrading culture. In the future, the mechanism of response to acetone for microbial cells will be studied.