Single Mutation in <i>iolT1</i> in <i>ptsG</i>-Deficient <i>Corynebacterium glutamicum</i> Enables Growth Boost in Xylose-Containing Media

Efficient co-utilization of glucose and xylose from lignocellulosic biomass remains a critical bottleneck limiting the viability of sustainable biorefineries. While <i>Corynebacterium glutamicum</i> has emerged as a promising industrial host due to its robustness, further improvements in...

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Main Authors: Katharina Hofer, Lynn S. Schwardmann, Jung-Won Youn, Volker F. Wendisch, Ralf Takors
Format: Article
Language:English
Published: MDPI AG 2025-07-01
Series:Microorganisms
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Online Access:https://www.mdpi.com/2076-2607/13/7/1606
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author Katharina Hofer
Lynn S. Schwardmann
Jung-Won Youn
Volker F. Wendisch
Ralf Takors
author_facet Katharina Hofer
Lynn S. Schwardmann
Jung-Won Youn
Volker F. Wendisch
Ralf Takors
author_sort Katharina Hofer
collection DOAJ
description Efficient co-utilization of glucose and xylose from lignocellulosic biomass remains a critical bottleneck limiting the viability of sustainable biorefineries. While <i>Corynebacterium glutamicum</i> has emerged as a promising industrial host due to its robustness, further improvements in mixed-sugar co-utilization are needed. Here, we demonstrate how a single amino acid substitution can dramatically transform cellular sugar transport capacity. By combining rational strain engineering with continuous adaptive laboratory evolution, we evolved a <i>ptsG</i>-deficient <i>C. glutamicum</i> strain in glucose–xylose mixtures for 600 h under consistent selection pressure. Whole-genome sequencing revealed a remarkable finding: a single point mutation; exchanging proline for alanine in the <i>myo</i>-inositol/proton symporter IolT1 was sufficient to boost glucose uptake by 83% and xylose uptake by 20%, while increasing the overall growth rate by 35%. This mutation, located in a highly conserved domain, likely disrupts an alpha helical structure, thus enhancing transport function. Reverse engineering confirmed that this single change alone reproduces the evolved phenotype, representing the first report of an engineered IolT1 variant in PTS-independent <i>C. glutamicum</i> that features significantly enhanced substrate uptake. These results both provide an immediately applicable engineering target for biorefinery applications and demonstrate the power of evolutionary approaches to identify non-intuitive solutions to complex metabolic engineering challenges.
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spelling doaj-art-b785d77ebb3841f7a6dee950f25e5ffc2025-08-20T02:47:22ZengMDPI AGMicroorganisms2076-26072025-07-01137160610.3390/microorganisms13071606Single Mutation in <i>iolT1</i> in <i>ptsG</i>-Deficient <i>Corynebacterium glutamicum</i> Enables Growth Boost in Xylose-Containing MediaKatharina Hofer0Lynn S. Schwardmann1Jung-Won Youn2Volker F. Wendisch3Ralf Takors4Institute of Biochemical Engineering, University of Stuttgart, 70569 Stuttgart, GermanyGenetics of Prokaryotes, Faculty of Biology and CeBiTec, Bielefeld University, 33615 Bielefeld, GermanyInstitute of Microbiology, University of Stuttgart, 70569 Stuttgart, GermanyGenetics of Prokaryotes, Faculty of Biology and CeBiTec, Bielefeld University, 33615 Bielefeld, GermanyInstitute of Biochemical Engineering, University of Stuttgart, 70569 Stuttgart, GermanyEfficient co-utilization of glucose and xylose from lignocellulosic biomass remains a critical bottleneck limiting the viability of sustainable biorefineries. While <i>Corynebacterium glutamicum</i> has emerged as a promising industrial host due to its robustness, further improvements in mixed-sugar co-utilization are needed. Here, we demonstrate how a single amino acid substitution can dramatically transform cellular sugar transport capacity. By combining rational strain engineering with continuous adaptive laboratory evolution, we evolved a <i>ptsG</i>-deficient <i>C. glutamicum</i> strain in glucose–xylose mixtures for 600 h under consistent selection pressure. Whole-genome sequencing revealed a remarkable finding: a single point mutation; exchanging proline for alanine in the <i>myo</i>-inositol/proton symporter IolT1 was sufficient to boost glucose uptake by 83% and xylose uptake by 20%, while increasing the overall growth rate by 35%. This mutation, located in a highly conserved domain, likely disrupts an alpha helical structure, thus enhancing transport function. Reverse engineering confirmed that this single change alone reproduces the evolved phenotype, representing the first report of an engineered IolT1 variant in PTS-independent <i>C. glutamicum</i> that features significantly enhanced substrate uptake. These results both provide an immediately applicable engineering target for biorefinery applications and demonstrate the power of evolutionary approaches to identify non-intuitive solutions to complex metabolic engineering challenges.https://www.mdpi.com/2076-2607/13/7/1606<i>Corynebacterium glutamicum</i>adaptive laboratory evolutionmixed carbon source<i>iolT1</i><i>ptsG</i><i>iolR</i>
spellingShingle Katharina Hofer
Lynn S. Schwardmann
Jung-Won Youn
Volker F. Wendisch
Ralf Takors
Single Mutation in <i>iolT1</i> in <i>ptsG</i>-Deficient <i>Corynebacterium glutamicum</i> Enables Growth Boost in Xylose-Containing Media
Microorganisms
<i>Corynebacterium glutamicum</i>
adaptive laboratory evolution
mixed carbon source
<i>iolT1</i>
<i>ptsG</i>
<i>iolR</i>
title Single Mutation in <i>iolT1</i> in <i>ptsG</i>-Deficient <i>Corynebacterium glutamicum</i> Enables Growth Boost in Xylose-Containing Media
title_full Single Mutation in <i>iolT1</i> in <i>ptsG</i>-Deficient <i>Corynebacterium glutamicum</i> Enables Growth Boost in Xylose-Containing Media
title_fullStr Single Mutation in <i>iolT1</i> in <i>ptsG</i>-Deficient <i>Corynebacterium glutamicum</i> Enables Growth Boost in Xylose-Containing Media
title_full_unstemmed Single Mutation in <i>iolT1</i> in <i>ptsG</i>-Deficient <i>Corynebacterium glutamicum</i> Enables Growth Boost in Xylose-Containing Media
title_short Single Mutation in <i>iolT1</i> in <i>ptsG</i>-Deficient <i>Corynebacterium glutamicum</i> Enables Growth Boost in Xylose-Containing Media
title_sort single mutation in i iolt1 i in i ptsg i deficient i corynebacterium glutamicum i enables growth boost in xylose containing media
topic <i>Corynebacterium glutamicum</i>
adaptive laboratory evolution
mixed carbon source
<i>iolT1</i>
<i>ptsG</i>
<i>iolR</i>
url https://www.mdpi.com/2076-2607/13/7/1606
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