Aspergillus nidulans mutants affected in acetate metabolism isolated as lipid nonutilizers.
Interest in extracellular fungal lipases has increased mainly because of their industrial applications. However, no studies have been done on a genetically well characterized filamentous fungus like Aspergillus nidulans. Here we show that A. nidulans produces an extracellular lipase when grown in solid or liquid cultures containing lipids as carbon source. This lipase is glucose-repressed in a creA-independent fashion. Seven mutants isolated by their inability to utilize lipids as sole carbon source were also unable to utilize acetate as sole carbon source. Representative mutants from each of three complementation groups were tested for allelism with strains carrying well known mutations affecting acetate metabolism. They were found to contain acuD (Isocitrate lyase), acuF (PEP carboxykinase), and acuE (Malate synthase) alleles. Screening of lipid nonutilizing mutants for growth in acetate provides a method for the isolation of both lipase minus and new acetate metabolism mutants.
Kawasaki
L
L
Departamento de Alimentos y Biotecnología, Facultad de Química, UNAM, México, D.F.
Farrés
A
A
Aguirre
J
J
D000085:Acetates / Q000378:metabolism*; D000483:Alleles; D001233:Aspergillus nidulans / Q000201:enzymology* / Q000254:growth & development; D004794:Enzyme Repression; D005816:Genetic Complementation Test; D007522:Isocitrate Lyase / Q000235:genetics; D008049:Lipase / Q000096:biosynthesis*; D050356:Lipid Metabolism; D008292:Malate Synthase / Q000235:genetics; D009154:Mutation; D000069463:Olive Oil; D010729:Phosphoenolpyruvate Carboxykinase (GTP) / Q000235:genetics; D010938:Plant Oils / Q000378:metabolism; D012641:Selection, Genetic; D014280:Triglycerides / Q000378:metabolism
D000085:Acetates; D000069463:Olive Oil; D010938:Plant Oils; D014280:Triglycerides; D008292:Malate Synthase; D008049:Lipase; D010729:Phosphoenolpyruvate Carboxykinase (GTP); D007522:Isocitrate Lyase; C005830:tributyrin