GENETIC-MODIFICATION OF AN ECHINOCANDIN B-PRODUCING STRAIN OF ASPERGILLUS-NIDULANS TO PRODUCE MUTANTS BLOCKED IN STERIGMATOCYSTIN BIOSYNTHESIS
GENETIC-MODIFICATION OF AN ECHINOCANDIN B-PRODUCING STRAIN OF ASPERGILLUS-NIDULANS TO PRODUCE MUTANTS BLOCKED IN STERIGMATOCYSTIN BIOSYNTHESIS
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DOI：
10.1007/bf01577222
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发表时间：
1994-11-01
期刊：
影响因子：
--
通讯作者：
MCGILVRAY, D
中科院分区：
文献类型：
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作者：
HODGES, RL;HODGES, DW;MCGILVRAY, D
棘白菌素B（ECB）是一种脂多肽，用于化学生产抗念珠菌制剂Cilofungin（TM），其生产是通过使用构巢曲霉菌株发酵完成的。 除了ECB，这种发酵还产生大量的杂色曲霉素（ST），一种结构上与黄曲霉毒素相关的强致癌物质。 通过对多倍体生产菌株C747进行遗传修饰，产生ST生物合成途径阻断的突变体。 包括以下步骤：（i）通过用纺锤体纤维毒素甲基1-（ii）使用UV照射诱变单倍体分离物;和（iii）通过薄层色谱法筛选不能产生ST的突变体。 分离出6个ST生产受阻的突变体。 所有六个仍然能够产生与单倍体菌株C747-GR 14数量相当的ECB。 其中一个突变体被证明是染色体易位的结果。
The production of echinocandin B (ECB), a lipopolypeptide used for chemical manufacture of the anti-Candida agent Cilofungin (TM), was accomplished by fermentation using a strain of Aspergillus nidulans. In addition to ECB, this fermentation also produces a significant amount of sterigmatocystin (ST), a potent carcinogen structurally related to the aflatoxins. Mutants blocked in the ST biosynthetic pathway were created by genetic modification of the polyploid production strain C747. The following steps were involved: (i) reduction of the genotype to haploid by treatment with the spindle fiber poison methyl 1-(butylcarbomoyl)-2-benzimidazole carbamate (MBC), using colony morphology, conidia size, and the ability to obtain 5-fluoro-orotic acid (5-FOA)-resistant mutants as criteria for ploidy; (ii) mutagenesis of a haploid isolate using UV irradiation; and (iii) screening of mutants for inability to produce ST by thin layer chromatography. Six mutants blocked in ST production were isolated. All six remained capable of producing ECB equivalent in quantity to the haploid strain C747-GR14. One of the mutants was shown to be the result of a chromosomal translocation.