English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Background  Glucose transporters play an important role in the fermentation of citric acid. In this study, a high-affinity glucose transporter (HGT1) was identified and overexpressed in the industrial strain  A. niger  CGMCC 10142. HGT1-overexpressing strains using the P gla A and P aox1  promoters were constructed to verify the glucose transporter functions.    Result  As hypothesized, the HGT1-overexpressing strains showed higher citric acid production and lower residual sugar contents. The best-performing strain  A. niger  20-15 exhibited a reduction of the total sugar content and residual reducing sugars by 16.5 and 44.7%, while the final citric acid production was significantly increased to 174.1 g/L, representing a 7.3% increase compared to  A. niger  CGMCC 10142. Measurement of the mRNA expression levels of relevant genes at different time-points during the fermentation indicated that in addition to HGT1, citrate synthase and glucokinase were also expressed at higher levels in the overexpression strains.    Conclusion  The results indicate that HGT1 overexpression resolved the metabolic bottleneck caused by insufficient sugar transport and thereby improved the sugar utilization rate. This study demonstrates the usefulness of the high-affinity glucose transporter HGT1 for improving the citric acid fermentation process of  Aspergillus niger  CGMCC 10142.    Supplementary Information  The online version contains supplementary material available at 10.1186/s12934-021-01659-3.

microbial cell factories

Improving citric acid production of an industrial Aspergillus niger CGMCC 10142: identification and overexpression of a high-affinity glucose transporter with different promoters