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Updated: Feb 18, 2026

Extraction and Quantification of Soluble, Radiolabeled Inositol Polyphosphates from Different Plant Species using SAX-HPLC
Published on: June 26, 2020
The myo-inositol/proton symporter IolT1 contributes to d-xylose uptake in Corynebacterium glutamicum
Christian Brüsseler1, Andreas Radek1, Niklas Tenhaef1
1Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich D-52425, Germany.
Abstract:
Corynebacterium glutamicum has been engineered to utilize d-xylose as sole carbon and energy source. Recently, a C. glutamicum strain has been optimized for growth on defined medium containing d-xylose by laboratory evolution, but the mutation(s) attributing to the improved-growth phenotype could not be reliably identified. This study shows that loss of the transcriptional repressor IolR is responsible for the increased growth performance on defined d-xylose medium in one of the isolated mutants. Underlying reason is derepression of the gene for the glucose/myo-inositol permease IolT1 in the absence of IolR, which could be shown to also contribute to d-xylose uptake in C. glutamicum. IolR-regulation of iolT1 could be successfully repealed by rational engineering of an IolR-binding site in the iolT1-promoter. This minimally engineered C. glutamicum strain bearing only two nucleotide substitutions mimics the IolR loss-of-function phenotype and allows for a high growth rate on d-xylose-containing media (µmax = 0.24 ± 0.01 h-1).
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