4.7 Article

Enhancement of fatty acid degradation pathway promoted glucoamylase synthesis in Aspergillus niger

期刊

MICROBIAL CELL FACTORIES
卷 21, 期 1, 页码 -

出版社

BMC
DOI: 10.1186/s12934-022-01966-3

关键词

Metabolic engineering; Microbial cell factories; Aspergillus niger; Glucoamylase; Fatty acids degradation; Chemostat; Tet-on

资金

  1. National Key Research and Development Program of China [2020YFA0907800]

向作者/读者索取更多资源

This study suggests that glucoamylase production in A. niger can be significantly enhanced by overexpressing genes fadE and fadA involved in the fatty acid degradation pathway. Harnessing intracellular fatty acids may be a strategy to improve enzyme production in the cell factory of Aspergillus niger.
Background: Our recent multi-omics analyses of glucoamylase biosynthesis in Aspergillus niger (A. niger) suggested that lipid catabolism was significantly up-regulated during high-yield period under oxygen limitation. Since the catabolism of fatty acids can provide energy compounds such as ATP and important precursors such as acetyl-CoA, we speculated that enhancement of this pathway might be beneficial to glucoamylase overproduction. Results: Based on previous transcriptome data, we selected and individually overexpressed five candidate genes involved in fatty acid degradation under the control of the Tet-on gene switch in A. niger. Overexpression of the fadE, fadA and cyp genes increased the final specific enzyme activity and total secreted protein on shake flask by 21.3 similar to 31.3% and 16.0 similar to 24.2%, respectively. And a better inducible effect by doxycycline was obtained from early logarithmic growth phase (18 h) than stationary phase (42 h). Similar with flask-level results, the glucoamylase content and total extracellular protein in engineered strains OE-fadE (overexpressing fadE) and OE-fadA (overexpressing fadA) on maltose-limited chemostat cultivation were improved by 31.2 similar to 34.1% and 35.1 similar to 38.8% compared to parental strain B36. Meanwhile, intracellular free fatty acids were correspondingly decreased by 41.6 similar to 44.6%. The metabolomic analysis demonstrated intracellular amino acids pools increased 24.86% and 18.49% in two engineered strains OE-fadE and OE-fadA compared to B36. Flux simulation revealed that increased ATP, acetyl-CoA and NADH was supplied into TCA cycle to improve amino acids synthesis for glucoamylase overproduction. Conclusion: This study suggested for the first time that glucoamylase production was significantly improved in A. niger by overexpression of genes fadE and fadA involved in fatty acids degradation pathway. Harnessing the intracellular fatty acids could be a strategy to improve enzyme production in Aspergillus niger cell factory.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.7
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据