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Harscoet, E.

Publications and source records attributed to Harscoet, E..

2 recordsLinked to original sources

Acetate as a metabolic booster for glucose-based bioproduction in Escherichia coli

Escherichia coli, a key workhorse in industrial biotechnology, is commonly grown on glucose, which supports rapid growth but leads to acetate overflow, which instead inhibits growth, diverts carbon from the production pathway, and reduces productivity. Recent studies suggest that acetate may also have beneficial effects in glucose-grown E. coli, but its potential in bioprocesses remains unexplored. In this study, we systematically investigated acetates impact on bioproduction using a kinetic model of glucose and acetate metabolism in E. coli. The model predicts that acetate can enhance bioproduction in glucose-grown E. coli through three mechanisms: (i) by minimizing acetate overflow, thereby reducing carbon loss, (ii) by increasing acetyl-CoA levels, thereby boosting the biosynthetic flux of acetyl-CoA-derived compounds, and (iii) by promoting biomass accumulation, thus improving overall productivity. We experimentally validated the predictions of the model for mevalonate and 3-hydroxypropionate production, where acetate supplementation increased productivity by 117% and 34%, respectively. Our findings provide a valuable framework for optimizing E. coli-based bioprocesses and highlight acetates underutilized potential in biotechnology. By leveraging acetate from waste streams as a metabolic booster, this approach could contribute to more sustainable and environmentally friendly bioprocesses. Highlights- A kinetic model was used for rational optimization of E. coli-based bioprocesses - Acetate can enhance growth and production of acetyl-CoA-derived bioproducts - Model predictions were validated for mevalonate and 3-hydroxypropionate production - Acetate can be used as a metabolic booster for glucose-based bioproduction in E. coli

systems biology↗

Fetal estrogens are not involved in sex determination but critical for early ovarian differentiation in rabbits.

AROMATASE, encoded by the CYP19A1 gene, is the cytochrome enzyme responsible for the synthesis of estrogens in vertebrates. In most mammals a peak of expression of the CYP19A1 gene occurs in the fetal XX gonad when sexual differentiation starts up. To elucidate the role of this peak, we produced 3 lines of TALEN genetically edited CYP19A1 KO rabbits, that were void of any production of estradiol. All KO XX rabbits developed as females, with aberrantly small sized ovaries at adulthood, an almost empty reserve of primordial follicles and very few large antrum follicles. Ovulation never occurred. Our histological, immunohistological and transcriptomic analyses showed that the surge of estradiol in the XX fetal rabbit gonad is dispensable for its determination as an ovary, or for meiosis. However, it is mandatory for the high proliferation and differentiation of both somatic and germ cells, and consequently for the establishment of the ovarian reserve.

developmental biology↗