文献类型：期刊文献

英文题名：Integrated isotope-assisted metabolomics and 13C metabolic flux analysis reveals metabolic flux redistribution for high glucoamylase production by Aspergillus niger

作者：Lu, Hongzhong[1];Liu, Xiaoyun[1];Huang, Mingzhi[1];Xia, Jianye[1];Chu, Ju[1];Zhuang, Yingping[1];Zhang, Siliang[1];Noorman, Henk[2]

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[2]DSM Biotechnol Ctr, NL-2600 MA Delft, Netherlands

年份：2015

卷号：14

外文期刊名：MICROBIAL CELL FACTORIES

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000361442000001)】；

基金：This work was financially supported by Royal DSM (Delft, the Netherlands) and partially supported by National Basic Research Program (973 Program 2013CB733600), NWO-MoST Joint Program (2013DFG32630), National High Technology Research and Development Program of China (863 Program 2012AA021201) and National Key Technology R&D Program (2012BAI44G01).

语种：英文

外文关键词：Aspergillus niger; Glucoamylase; C-13 metabolic flux analysis; Metabolomics; Cofactor metabolism

摘要：Background: Aspergillus niger is widely used for enzyme production and achievement of high enzyme production depends on the comprehensive understanding of cell's metabolic regulation mechanisms. Results: In this paper, we investigate the metabolic differences and regulation mechanisms between a high glucoamylase-producing strain A. niger DS03043 and its wild-type parent strain A. niger CBS513.88 via an integrated isotope-assisted metabolomics and 13C metabolic flux analysis approach. We found that A. niger DS03043 had higher cell growth, glucose uptake, and glucoamylase production rates but lower oxalic acid and citric acid secretion rates. In response to above phenotype changes, A. niger DS03043 was characterized by an increased carbon flux directed to the oxidative pentose phosphate pathway in contrast to reduced flux through TCA cycle, which were confirmed by consistent changes in pool sizes of metabolites. A higher ratio of ATP over AMP in the high producing strain might contribute to the increase in the PP pathway flux as glucosephosphate isomerase was inhibited at higher ATP concentrations. A. niger CBS513.88, however, was in a higher redox state due to the imbalance of NADH regeneration and consumption, resulting in the secretion of oxalic acid and citric acid, as well as the accumulation of intracellular OAA and PEP, which may in turn result in the decrease in the glucose uptake rate. Conclusions: The application of integrated metabolomics and 13C metabolic flux analysis highlights the regulation mechanisms of energy and redox metabolism on flux redistribution in A. niger.