Pectolytic enzymes of_ Aspergillus niger. III. The action of pectin and of some pectic degradation substances on the formation of polygalacturonases
Rev Roum Biochim 4(3): 219-229
The action of pectin and of certain degradation products, oli-gouronide and D-galacturonic acid, on the formation of polygalacturonases (PG) by A. niger was studied. A. niger showed no genetic changes in the biosynthesis of PG in cultivation for 60 serial passages in the presence of pectin; this is probably due to the constitutive formation of PG by A. niger ICA-34. Exogenous DNA, extracted from A. niger and added to the fungal cultures brings about a sitmulation of PG synthesis, especially at intracellular level. Oligouronides, and especially D-galacturonic acid, produce a decrease in the formation of mycelium and of PG. D-galacturonic acid appears to intervene in the genetic control of PG biosynthesis, either directly or indirectly by one of its degradation products.