Cotty P J, Cleveland T E, Brown R L, Mellon J E
Southern Regional Research Center, U.S. Department of Agriculture, New Orleans, Louisiana 70179-0687.
Appl Environ Microbiol. 1990 Dec;56(12):3885-7. doi: 10.1128/aem.56.12.3885-3887.1990.
Pectinase production by Aspergillus flavus was determined by measuring clear zones formed around colonies stained with ruthenium red. Several isolates produced red zones instead of clear zones. Red zones were reproduced with pectinesterase and correlated with absence of specific polygalacturonases. Of 87 isolates tested, 15 produced red zones.