Dataset Information

Adaptive Evolution Reveals Mechanisms of Isobutanol Tolerance in Zymomonas mobilis

ABSTRACT:

Isobutanol production has been demonstrated in E. coli and Z. mobilis using heterologous pathways, with titers reaching up to 60% of the theoretical yield under optimized conditions. However, these results often depend on impractical setups, such as continuous product extraction, oxygenation, or nutrient supplementation, and still produce poorly growing strains with unstable pathway expression. In Z. mobilis, carbon flux remains strongly biased toward ethanol, which competes directly with isobutanol for pyruvate and reducing power.

Here, to address this challenge, we conducted an adaptive evolution experiment to improve isobutanol resistance in Z. mobilis. The bacterium was subjected to prolonged growth under gradually increasing isobutanol concentrations, leading to the isolation of evolved strains with significantly enhanced tolerance. Whole-genome sequencing revealed conserved adaptive mechanisms, with genetic alterations affecting a small set of target genes shared across resistant strains. By linking these mutations to improved growth kinetics and resistance profiles, we provide insights into the genetic and physiological basis of isobutanol tolerance, guiding future metabolic engineering efforts.

INSTRUMENT(S): Liquid Chromatography MS - negative - reverse-phase, Liquid Chromatography MS - positive - reverse-phase

PROVIDER: MTBLS14081 | MetaboLights | 2026-03-18

REPOSITORIES: MetaboLights

ACCESS DATA

Dataset's files

Source:

			Action	DRS
	a_MTBLS14081_LC-MS_negative_reverse-phase_metabolite_profiling-1.txt	Txt
	a_MTBLS14081_LC-MS_negative_reverse-phase_metabolite_profiling.txt	Txt
	a_MTBLS14081_LC-MS_positive_reverse-phase_metabolite_profiling.txt	Txt
	i_Investigation.txt	Txt
	m_MTBLS14081_LC-MS_negative_reverse-phase_metabolite_profiling-1_v2_maf.tsv	Tabular

Items per page:

1 - 5 of 8

Similar Datasets

Project description:BACKGROUND:Isobutanol is a promising next generation biofuel with demonstrated high yield microbial production, but the toxicity of this molecule reduces fermentation volumetric productivity and final titers. Organic solvent tolerance is a complex, multigenic phenotype that has been recalcitrant to rational engineering approaches. We apply experimental evolution followed by genome resequencing and a gene expression study to elucidate genetic bases on adaptation to exogenous isobutanol stress. RESULTS:The adaptations acquired in our evolved lineages exhibit antagonistic pleiotropy between minimal and rich medium, and appear to be specific to the effects of longer chain alcohols. By examining genotypic adaptation in multiple independent lineages, we find evidence of parallel evolution in hfq, mdh, acrAB, gatYZABCD, and rph genes. Many isobutanol tolerant lineages show reduced rpoS activity, perhaps related to mutations in hfq or acrAB. Consistent with the complex, multigenic nature of solvent tolerance, we observe adaptations in a diversity of cellular processes. Many adaptations appear to involve epistasis between different mutations, implying a rugged fitness landscape for isobutanol tolerance. We observe a trend of evolution targeting post-transcriptional regulation and high centrality nodes of biochemical networks. Collectively, the genotypic adaptations we observe suggest mechanisms of adaptation to isobutanol stress based on remodelling the cell envelope and surprisingly, stress response attenuation. CONCLUSIONS:We have discovered a set of genotypic adaptations that confer increased tolerance to exogenous isobutanol stress. Our results are immediately useful to efforts to engineer more isobutanol tolerant host strains of E. coli for isobutanol production. We suggest that rpoS and post-transcriptional regulators, such as hfq, RNA helicases, and sRNAs may be interesting mutagenesis targets for futurue global phenotype engineering. Two strains (WT strain and G3.2 mutant strain), each with two culture conditions (with and without isobutanol in medium). Three biological replicates for each strain/culture condition. Twelve samples in total.

Dataset Information

Adaptive Evolution Reveals Mechanisms of Isobutanol Tolerance in Zymomonas mobilis

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets