Association of Candida guilliermondii with amylolytic filamentous fungi on preharvest corn

Abstract

Candida guilliermondii var. guilliermondii was the dominant yeast isolated from preharvest Georgia corn and comprised 3.6–47.0% of the total fungi as measured by dilution plating. The yeast was confined mainly to kernels visibly molded by filamentous fungi, primarily Fusarium moniliforme and Aspergillus flavus. When grown in liquid shake culture, Cand. guilliermondii was unable to utilize starch. Growth of the yeast increased considerably when associated with amylolytic F. moniliforme or Asp. flavus. Utilization of starch hydrolyzates by Cand. guilliermondii in mixed cultures was reflected by a decrease in reducing sugar concentrations and a reduction in growth of F. moniliforme and Asp. flavus. When glucose replaced starch as a carbon source, F. moniliforme and Asp. flavus did not affect the maximum growth of Cand. guilliermondii. The association between Cand. guilliermondii and amylolytic filamentous fungi on preharvest corn is probably commensalistic.