crgA调控三孢布拉霉合成类胡萝卜素

Regulation effect of crgA on carotenoid production in Blakeslea trispora

摘要:

[目的]探究crgA基因在三孢布拉霉合成类胡萝卜素过程中的调控作用。[方法]克隆三孢布拉霉crgA基因并利用split-marker策略敲除该基因；在表型特征、关键酶基因转录水平、类胡萝卜素合成水平等方面将基因敲除株与野生株进行比较分析。[结果]与野生型菌株相比，crgA基因敲除菌产孢能力明显下降，而类胡萝卜素合成途径中的关键酶基因转录水平明显提高，在发酵120 h后β-胡萝卜素的积累量提高了31.2%。将crgA基因重新导入到敲除菌后，该菌的性状恢复至野生型。[结论]crgA基因调控三孢布拉霉的生长和产孢能力，并通过调控类胡萝卜素关键酶基因表达来调控类胡萝卜素的合成，是一个负调控因子。

Abstract:

[Objective] We studied the regulation of crgA on carotenoid biosynthesis by Blakeslea trispora.[Methods] crgA was cloned from B. trispora and then disrupted by using split-marker strategy. Phenotypic characteristics, transcription of key enzyme genes and carotenoid accumulation between the wide-type and mutant strain were compared.[Results] In contrast to those of wild-type strain, the spore-forming ability of the mutant was weakened but transcription of key enzyme genes in the pathway of carotenoid biosynthesis increased and β-carotene production in the mycelia was improved by 31.2% after cultured for 120 h. After crgA was transformed into the mutant, the strain restored the phenotype as those of the wild-type strain.[Conclusion] crgA could regulate spore-forming and mycelia growth. Besides, the gene controlled carotenoid synthesis by regulating the transcription of key enzyme genes, which indicates that crgA is a negative regulator in Blakeslea trispora.