HurLey等发现,抗肿瘤抗生素恩霉素(Anthram-ycin)是由色氨酸,酪氨酸和蛋氨酸衍生而来。本文作者试图研究产生恩霉素时有关芳香氨基酸的部份调节机制。用N-甲基-N′-硝基-N-亚硝基奎尼定(NTG)或青霉素G处理S.refuineus得到酪氨酸缺陷型变株,然后用变株与野生型菌株同时进行比较试验,发现该变株能生长在添加酪氨酸的最低营养培基(MM)上,而不生长在仅含MM培养基上,说明它是单一营养缺陷株。变株在含对-羟苯丙酮酸的MM培基上不生长,因而估计它在对-羟苯丙酮酸转氨酶部位受损,致使它不能使用该前体物。但野生型和缺陷型变株两者都能利用谷酰胺,而且两者的对-羟苯丙氨酸转氨酶的活性都 Hurlay et al. Found that the anti-tumor antibiotic Anthram-ycin is derived from tryptophan, tyrosine and methionine. The authors attempted to study the partial regulatory mechanism of aromatic amino acids when producing enoximycin. Typhine-deficient mutants were obtained by treating S. refuineus with N-methyl-N’-nitro-N-nitrosoquinidine (NTG) or penicillin G and then compared with wild-type strains It was found that the mutant was able to grow on the minimal nutrient medium (MM) supplemented with tyrosine and not on MM medium alone, indicating that it is a single auxotrophic strain. The mutant strain does not grow on the MM culture medium containing para-hydroxyphenylpyruvate and is therefore estimated to be impaired at the para-hydroxyphenylpyruvate transaminase site, rendering it incapable of using the precursor. However, both wild-type and mutant strains can utilize glutamine, and both p-hydroxyphenylalanine aminotransferase activity