Isolation of mutants deficient in acetyl-CoA synthetase and a possible regulator of acetate induction in Aspergillus niger

摘要

Acetate-non-utilizing mutants in Aspergillus niger were selected by resistance to 1.2 propionate in the presence of 0.1 glucose. Mutants showing normal morphology fell into two complementation groups. One class of mutant racked acetyl-CoA synthetase but had high levels of isocitrate lyase, while the second class showed reduced levels of both acetyl-CoA synthetase and isocitrate lyase compared to the wild-type strain. By analogy with mutants selected by resistance to 1 2 propionate in Aspergillus nidulans, the properties of the mutants in A. niger suggest that the mutations are either in the structural gene for acetyl-CoA synthetase (acuA) or in a possible regulatory gene of acetate induction (acuB). A third class of mutant in a different complementation group was obtained which had abnormal morphology (yellow mycelium and few conidia); the specific lesion in these mutants has not been determined. References: 29