| Title |
Effects of nitrogen availability on polymalic acid biosynthesis in the yeast-like fungus Aureobasidium pullulans
|
|---|---|
| Published in |
Microbial Cell Factories, August 2016
|
| DOI | 10.1186/s12934-016-0547-y |
| Pubmed ID | |
| Authors |
Yongkang Wang, Xiaodan Song, Yongjun Zhang, Bochu Wang, Xiang Zou |
| Abstract |
Polymalic acid (PMA) is a novel polyester polymer that has been broadly used in the medical and food industries. Its monomer, L-malic acid, is also a potential C4 platform chemical. However, little is known about the mechanism of PMA biosynthesis in the yeast-like fungus, Aureobasidium pullulans. In this study, the effects of different nitrogen concentration on cell growth and PMA biosynthesis were investigated via comparative transcriptomics and proteomics analyses, and a related signaling pathway was also evaluated. A high final PMA titer of 44.00 ± 3.65 g/L (49.9 ± 4.14 g/L of malic acid after hydrolysis) was achieved in a 5-L fermentor under low nitrogen concentration (2 g/L of NH4NO3), which was 18.3 % higher yield than that obtained under high nitrogen concentration (10 g/L of NH4NO3). Comparative transcriptomics profiling revealed that a set of genes, related to the ribosome, ribosome biogenesis, proteasome, and nitrogen metabolism, were significantly up- or down-regulated under nitrogen sufficient conditions, which could be regulated by the TOR signaling pathway. Fourteen protein spots were identified via proteomics analysis, and were found to be associated with cell division and growth, energy metabolism, and the glycolytic pathway. qRT-PCR further confirmed that the expression levels of key genes involved in the PMA biosynthetic pathway (GLK, CS, FUM, DAT, and MCL) and the TOR signaling pathway (GS, TOR1, Tap42, and Gat1) were upregulated due to nitrogen limitation. Under rapamycin stress, PMA biosynthesis was obviously inhibited in a dose-dependent manner, and the transcription levels of TOR1, MCL, and DAT were also downregulated. The level of nitrogen could regulate cell growth and PMA biosynthesis. Low concentration of nitrogen was beneficial for PMA biosynthesis, which could upregulate the expression of key genes involved in the PMA biosynthesis pathway. Cell growth and PMA biosynthesis might be mediated by the TOR signaling pathway in response to nitrogen. This study will help us to deeply understand the molecular mechanisms of PMA biosynthesis, and to develop an effective process for the production of PMA and malic acid chemicals. |
X Demographics
The data shown below were collected from the profiles of 3 X users who shared this research output. Click here to find out more about how the information was compiled.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| United States | 1 | 33% |
| Unknown | 2 | 67% |
Demographic breakdown
| Type | Count | As % |
|---|---|---|
| Members of the public | 3 | 100% |
Mendeley readers
The data shown below were compiled from readership statistics for 22 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Unknown | 22 | 100% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Student > Ph. D. Student | 6 | 27% |
| Student > Bachelor | 4 | 18% |
| Student > Postgraduate | 2 | 9% |
| Other | 1 | 5% |
| Researcher | 1 | 5% |
| Other | 1 | 5% |
| Unknown | 7 | 32% |
| Readers by discipline | Count | As % |
|---|---|---|
| Biochemistry, Genetics and Molecular Biology | 3 | 14% |
| Engineering | 3 | 14% |
| Agricultural and Biological Sciences | 3 | 14% |
| Chemical Engineering | 1 | 5% |
| Chemistry | 1 | 5% |
| Other | 1 | 5% |
| Unknown | 10 | 45% |
Attention Score in Context
This research output has an Altmetric Attention Score of 1. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 24 August 2016.
All research outputs
#17,812,737
of 22,883,326 outputs
Outputs from Microbial Cell Factories
#1,127
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Outputs of similar age
#248,840
of 343,744 outputs
Outputs of similar age from Microbial Cell Factories
#23
of 38 outputs
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