Ventura L, Ramón D, Pérez-González J A
Unidad de Bioingeniería de los Alimentos, Instituto de Agroquímica y Tecnología de los Alimentos (C.S.I.C.), Valencia, Spain.
FEMS Microbiol Lett. 1992 Dec 1;78(2-3):187-91. doi: 10.1016/0378-1097(92)90023-h.
Using filtration enrichment techniques, an Aspergillus terreus arginine auxotrophic strain which contains a mutation that abolishes ornithine transcarbamylase (OTCase) activity has been isolated. This mutant has been genetically transformed with the cloned Aspergillus nidulans OTCase gene. Prototrophic transformants arose at a frequency of about 50 transformants per microgram of plasmid DNA. Southern blot analysis of DNA from the transformants showed that the transforming DNA was ectopically integrated at different locations in the A. terreus genome, often in multiple tandem copies. The transformants were phenotypically stable for several mitotic divisions and retained their capacity to produce extracellular enzymes.
利用过滤富集技术，分离出了一株土曲霉精氨酸营养缺陷型菌株，该菌株含有一个导致鸟氨酸转氨甲酰酶（OTCase）活性丧失的突变。已用克隆的构巢曲霉OTCase基因对该突变体进行了遗传转化。原养型转化体的出现频率约为每微克质粒DNA产生50个转化体。对转化体DNA的Southern印迹分析表明，转化DNA异位整合到土曲霉基因组的不同位置，通常以多个串联拷贝的形式存在。这些转化体在几个有丝分裂周期中表型稳定，并保留了产生胞外酶的能力。
