Fan Junxia, Zhang Zhe, Long Chuannan, He Bin, Hu Zhihong, Jiang Chunmiao, Zeng Bin
Jiangxi Key Laboratory of Bioprocess Engineering and Co-Innovation Center for In-Vitro Diagnostic Reagents and Devices of Jiangxi Province, College of Life Sciences, Jiangxi Science and Technology Normal University, Nanchang, 330013, China.
World J Microbiol Biotechnol. 2020 Aug 12;36(9):136. doi: 10.1007/s11274-020-02912-4.
Glycerol dehydrogenase has been identified and characterized functionally in many species. However, little is known about glycerol dehydrogenase genes and their functions in Aspergillus oryzae. Here, a total of 45 glycerol dehydrogenase genes in Aspergillus oryzae were identified and renamed from AoGld1 to AoGld45 according to their chromosome distribution. They were classified into three groups based on phylogenetic analysis. Synteny analysis revealed that thirteen AoGld genes are conserved among Aspergillus species. Promoter analysis displayed that AoGld3 and AoGld13 harbored multiple binding elements of GATA-type transcription factors and zinc-finger protein msnA that were involved in nitrogen and kojic acid metabolism, respectively. Moreover, the AoGld3 deletion strain Δgld3 was generated by the CRISPR/Cas9 system, which had no visible growth defects compared with the control wild-type strain under the control and osmotic stress treatments. However, disruption of AoGld3 led to the inhibition of kojic acid production, and the expression of kojA, kojR was down-regulated in the Δgld3 strain. Furthermore, when kojA or kojR was overexpressed in the Δgld3 strain, the yield of kojic acid was restored, suggesting that AoGld3 is involved in kojic acid production through affecting the expression of kojR and kojA. Taken together, these findings provide new insights into our understanding of glycerol dehydrogenase and establish foundation for further study of their roles in Aspergillus oryzae.
甘油脱氢酶已在许多物种中得到鉴定并进行了功能表征。然而，关于米曲霉中甘油脱氢酶基因及其功能却知之甚少。在此，共鉴定出米曲霉中的45个甘油脱氢酶基因，并根据它们在染色体上的分布从AoGld1到AoGld45进行了重新命名。基于系统发育分析，它们被分为三组。共线性分析表明，13个AoGld基因在曲霉属物种中是保守的。启动子分析显示，AoGld3和AoGld13分别含有GATA型转录因子和锌指蛋白msnA的多个结合元件，它们分别参与氮代谢和曲酸代谢。此外，通过CRISPR/Cas9系统构建了AoGld3缺失菌株Δgld3，在对照和渗透胁迫处理下，与对照野生型菌株相比，该缺失菌株没有明显的生长缺陷。然而，AoGld3的缺失导致曲酸产量受到抑制，并且在Δgld3菌株中kojA和kojR的表达下调。此外，当在Δgld3菌株中过表达kojA或kojR时，曲酸产量得以恢复，这表明AoGld3通过影响kojR和kojA的表达参与曲酸的产生。综上所述，这些发现为我们理解甘油脱氢酶提供了新的见解，并为进一步研究它们在米曲霉中的作用奠定了基础。
