Kawasaki L, Farrés A, Aguirre J
Departamento de Alimentos y Biotecnología, Facultad de Química, UNAM, México, D.F.
Exp Mycol. 1995 Mar;19(1):81-5. doi: 10.1006/emyc.1995.1009.
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.
对细胞外真菌脂肪酶的兴趣主要因其工业应用而增加。然而，尚未对像构巢曲霉这样遗传特征明确的丝状真菌进行研究。在此我们表明，构巢曲霉在以脂质作为碳源的固体或液体培养基中生长时会产生一种细胞外脂肪酶。这种脂肪酶以不依赖creA的方式受到葡萄糖抑制。通过无法利用脂质作为唯一碳源而分离出的七个突变体也无法利用乙酸盐作为唯一碳源。对三个互补组中每组的代表性突变体与携带影响乙酸盐代谢的已知突变的菌株进行等位性测试。发现它们含有acuD（异柠檬酸裂解酶）、acuF（磷酸烯醇式丙酮酸羧激酶）和acuE（苹果酸合酶）等位基因。筛选不能利用脂质的突变体在乙酸盐中的生长情况，为分离脂肪酶缺陷型和新的乙酸盐代谢突变体提供了一种方法。
