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   Escherichia coli W3110  and a group of six isogenic derivatives, each displaying distinct specific rates of glucose consumption were characterized to determine levels of GFP production and population heterogeneity. These strains have single or combinatory deletions in genes encoding phosphoenolpyruvate:sugar phosphotransferase system (PTS) permeases as PtsG and ManX, as well as common components EI, Hpr protein and EIIA, also the non-PTS  Mgl  galactose/glucose ABC transporter. They have been transformed for expressing GFP based on a  lac -based expression vector, which is subject to bistability.    Results  These strains displayed specific glucose consumption and growth rates ranging from 1.75 to 0.45 g/g h and 0.54 to 0.16 h −1 , respectively. The rate of acetate production was strongly reduced in all mutant strains when compared with  W3110/pV21 . In bioreactor cultures, wild type  W3110/pV21  produced 50.51 mg/L GFP, whereas strains  WG/pV21  with inactive  PTS IICBGlc  and  WGM/pV21  with the additional inactivation of  PTS IIABMan  showed the highest titers of GFP, corresponding to 342 and 438 mg/L, respectively. Moreover, we showed experimentally that bistable expression systems, as  lac -based ones, induce strong phenotypic segregation among microbial populations.    Conclusions  We have demonstrated that reduction on glucose consumption rate in  E. coli  leads to an improvement of GFP production. Furthermore, from the perspective of phenotypic heterogeneity, we observed in this case that heterogeneous systems are also the ones leading to the highest performance. This observation suggests reconsidering the generally accepted proposition stating that phenotypic heterogeneity is generally unwanted in bioprocess applications.Electronic supplementary material  The online version of this article (10.1186/s12934-019-1073-5) contains supplementary material, which is available to authorized users.

microbial cell factories

Growth-dependent recombinant product formation kinetics can be reproduced through engineering of glucose transport and is prone to phenotypic heterogeneity