Comparison of isolates in the Chaetomium aureum species group by esterase isoenzyme analysis

Soluble protein extracts from 19 isolates of Chaetomium were subjected to isoelectric focusing in polyacrylamide gel rods. The isoelectric point (pI) values of esterase isoenzymes were determined and the data used to calculate coefficients of similarity. Isolates of C. aureum and C. trilaterale were electrophoretically distinct, whereas isolates of C. confusum, C. humicola, C. rubrogenum, and C. trilaterale were not distinguishable electrophoretically from each other. The profiles A, B, F, and G can be used to distinguish the species of C. atrobrunneum, C. aureum, C. cupreum and C. fusiforme. These results partly agreed with the morphologically based classification of the C. aureum species group. Certain esterase bands were found to be useful as diagnostic markers for differentiating Chaetomium species.