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Improving cytosolic aspartate biosynthesis increases glucoamylase production in Aspergillus niger under oxygen limitation

BACKGROUND: Glucoamylase is one of the most industrially applied enzymes, produced by Aspergillus species, like Aspergillus niger. Compared to the traditional ways of process optimization, the metabolic engineering strategies to improve glucoamylase production are relatively scarce. RESULTS: In the...

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Autores principales: Cao, Weiqiang, Wang, Guan, Lu, Hongzhong, Ouyang, Liming, Chu, Ju, Sui, Yufei, Zhuang, Yingping
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7118866/
https://www.ncbi.nlm.nih.gov/pubmed/32245432
http://dx.doi.org/10.1186/s12934-020-01340-1
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author Cao, Weiqiang
Wang, Guan
Lu, Hongzhong
Ouyang, Liming
Chu, Ju
Sui, Yufei
Zhuang, Yingping
author_facet Cao, Weiqiang
Wang, Guan
Lu, Hongzhong
Ouyang, Liming
Chu, Ju
Sui, Yufei
Zhuang, Yingping
author_sort Cao, Weiqiang
collection PubMed
description BACKGROUND: Glucoamylase is one of the most industrially applied enzymes, produced by Aspergillus species, like Aspergillus niger. Compared to the traditional ways of process optimization, the metabolic engineering strategies to improve glucoamylase production are relatively scarce. RESULTS: In the previous study combined multi-omics integrative analysis and amino acid supplementation experiment, we predicted four amino acids (alanine, glutamate, glycine and aspartate) as the limited precursors for glucoamylase production in A. niger. To further verify this, five mutants namely OE-ala, OE-glu, OE-gly, OE-asp1 and OE-asp2, derived from the parental strain A. niger CBS 513.88, were constructed respectively for the overexpression of five genes responsible for the biosynthesis of the four kinds of amino acids (An11g02620, An04g00990, An05g00410, An04g06380 and An16g05570). Real-time quantitative PCR revealed that all these genes were successfully overexpressed at the mRNA level while the five mutants exhibited different performance in glucoamylase production in shake flask cultivation. Notably, the results demonstrated that mutant OE-asp2 which was constructed for reinforcing cytosolic aspartate synthetic pathway, exhibited significantly increased glucoamylase activity by 23.5% and 60.3% compared to CBS 513.88 in the cultivation of shake flask and the 5 L fermentor, respectively. Compared to A. niger CBS 513.88, mutant OE-asp2 has a higher intracellular amino acid pool, in particular, alanine, leucine, glycine and glutamine, while the pool of glutamate was decreased. CONCLUSION: Our study combines the target prediction from multi-omics analysis with the experimental validation and proves the possibility of increasing glucoamylase production by enhancing limited amino acid biosynthesis. In short, this systematically conducted study will surely deepen the understanding of resources allocation in cell factory and provide new strategies for the rational design of enzyme production strains.
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spelling pubmed-71188662020-04-07 Improving cytosolic aspartate biosynthesis increases glucoamylase production in Aspergillus niger under oxygen limitation Cao, Weiqiang Wang, Guan Lu, Hongzhong Ouyang, Liming Chu, Ju Sui, Yufei Zhuang, Yingping Microb Cell Fact Research BACKGROUND: Glucoamylase is one of the most industrially applied enzymes, produced by Aspergillus species, like Aspergillus niger. Compared to the traditional ways of process optimization, the metabolic engineering strategies to improve glucoamylase production are relatively scarce. RESULTS: In the previous study combined multi-omics integrative analysis and amino acid supplementation experiment, we predicted four amino acids (alanine, glutamate, glycine and aspartate) as the limited precursors for glucoamylase production in A. niger. To further verify this, five mutants namely OE-ala, OE-glu, OE-gly, OE-asp1 and OE-asp2, derived from the parental strain A. niger CBS 513.88, were constructed respectively for the overexpression of five genes responsible for the biosynthesis of the four kinds of amino acids (An11g02620, An04g00990, An05g00410, An04g06380 and An16g05570). Real-time quantitative PCR revealed that all these genes were successfully overexpressed at the mRNA level while the five mutants exhibited different performance in glucoamylase production in shake flask cultivation. Notably, the results demonstrated that mutant OE-asp2 which was constructed for reinforcing cytosolic aspartate synthetic pathway, exhibited significantly increased glucoamylase activity by 23.5% and 60.3% compared to CBS 513.88 in the cultivation of shake flask and the 5 L fermentor, respectively. Compared to A. niger CBS 513.88, mutant OE-asp2 has a higher intracellular amino acid pool, in particular, alanine, leucine, glycine and glutamine, while the pool of glutamate was decreased. CONCLUSION: Our study combines the target prediction from multi-omics analysis with the experimental validation and proves the possibility of increasing glucoamylase production by enhancing limited amino acid biosynthesis. In short, this systematically conducted study will surely deepen the understanding of resources allocation in cell factory and provide new strategies for the rational design of enzyme production strains. BioMed Central 2020-04-03 /pmc/articles/PMC7118866/ /pubmed/32245432 http://dx.doi.org/10.1186/s12934-020-01340-1 Text en © The Author(s) 2020 Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.
spellingShingle Research
Cao, Weiqiang
Wang, Guan
Lu, Hongzhong
Ouyang, Liming
Chu, Ju
Sui, Yufei
Zhuang, Yingping
Improving cytosolic aspartate biosynthesis increases glucoamylase production in Aspergillus niger under oxygen limitation
title Improving cytosolic aspartate biosynthesis increases glucoamylase production in Aspergillus niger under oxygen limitation
title_full Improving cytosolic aspartate biosynthesis increases glucoamylase production in Aspergillus niger under oxygen limitation
title_fullStr Improving cytosolic aspartate biosynthesis increases glucoamylase production in Aspergillus niger under oxygen limitation
title_full_unstemmed Improving cytosolic aspartate biosynthesis increases glucoamylase production in Aspergillus niger under oxygen limitation
title_short Improving cytosolic aspartate biosynthesis increases glucoamylase production in Aspergillus niger under oxygen limitation
title_sort improving cytosolic aspartate biosynthesis increases glucoamylase production in aspergillus niger under oxygen limitation
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7118866/
https://www.ncbi.nlm.nih.gov/pubmed/32245432
http://dx.doi.org/10.1186/s12934-020-01340-1
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