Differentiation of Rhizomucor species by carbon source utilization and isoenzyme analysis

Nineteen Rhizomucor miehei and Rhizomucor pusillus isolates were assayed for their ability to utilize 87 various substrates as a single carbon source. Besides a difference in sucrose utilization, distinctive differences were found in the utilization of glycine, phenylalanine, and beta-alanine. Five isoenzyme systems also proved useful for the determination of markers of distinctive value at a species level. Data were used to obtain information about the genetic polymorphism of these species: a high degree of variability was found among the R. pusillus isolates, whereas the group of R. miehei isolates was more homogeneous genetically.