Deletion of the HXK2 gene in Saccharomyces cerevisiae enables mixed sugar fermentation of glucose and galactose in oxygen-limited conditions

Bae, Yi-Hyun; Kweon, Dae-Hyuk; Park, Yong-Cheol; Seo, Jin‐Ho

doi:10.1016/j.procbio.2014.01.030

Cited by 14 publications

(6 citation statements)

References 31 publications

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“…Our observations are consistent with a decrease in glucose consumption rate that was observed in a S. cerevisiae mutant deficient in the chromosomal HXK2 gene encoding hexokinase isozyme 2 (Bae et al, 2014).…”

Section: Namesupporting

confidence: 90%

“…4). This unexpected result implied that the preparation of the Leloir enzymes before glucose depletion is probably crucial for efficient utilization of galactose in mixed sugar fermentation, which is coincided with a previous study of galactose and glucose fermentation by a yeast strain (Bae et al, 2014). Meanwhile, only the transcriptional activation of the GAL genes by the relief of the glucose repression mechanism is insufficient to metabolize galactose in the presence of glucose.…”

Section: Analysis Of Transcription Levels Of the Gal Genessupporting

confidence: 85%

“…Meanwhile, only the transcriptional activation of the GAL genes by the relief of the glucose repression mechanism is insufficient to metabolize galactose in the presence of glucose. Overexpression of galactose transporters (S. cerevisiae Gal2p, or Kluyveromyces lactis Laci2p and Hgt1p (Baruffini et al, 2006)) in a batch culture using galactose and glucose did not yield improved galactose consumption in S. cerevisiae Dhxk2 (Bae et al, 2014), which possesses physiological properties similar to those of HJ7-14. These results indicated that the glucose-mediated inhibition on galactose transport may be another hurdle for efficient galactose consumption.…”

Section: Analysis Of Transcription Levels Of the Gal Genesmentioning

confidence: 93%

“…Overexpression of the PGM2 gene encoding phosphoglucomutase (Bro et al, 2005) and a truncated TUP1 gene encoding a transcription repressor (Lee et al, 2011) led to an increase in galactose consumption rate, compared to that observed with the corresponding parent strains. Deletion of the HXK2 gene coding for a hexokinase isozyme relieved the glucose-mediated catabolite repression and enhanced galactose consumption rate in a culture using galactose and glucose (Bae et al, 2014;Kummel et al, 2010). In addition, wild type strains of S. cerevisiae were screened newly with high ethanol producing performance from galactose under aerobic conditions .…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Evolutionary engineering of Saccharomyces cerevisiae for efficient conversion of red algal biosugars to bioethanol

Lee

Kim

Yoon

et al. 2015

Bioresource Technology

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Section: Namesupporting

confidence: 90%

Section: Analysis Of Transcription Levels Of the Gal Genessupporting

confidence: 85%

Section: Analysis Of Transcription Levels Of the Gal Genesmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Evolutionary engineering of Saccharomyces cerevisiae for efficient conversion of red algal biosugars to bioethanol

Lee

Kim

Yoon

et al. 2015

Bioresource Technology

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“…Because of the phenomenon known as catabolite repression, wild type Saccharomyces cerevisiae strains consume galactose only after glucose is depleted . The sequential consumption of mixed sugars and diauxic growth results in the reduction of overall productivity .…”

Section: Introductionmentioning

confidence: 99%

Enhanced production of 2,3‐butanediol in pyruvate decarboxylase‐deficient Saccharomyces cerevisiae through optimizing ratio of glucose/galactose

Choi

Kim

et al. 2016

Biotechnology Journal

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Galactose and glucose are two of the most abundant monomeric sugars in hydrolysates of marine biomasses. While Saccharomyces cerevisiae can ferment galactose, its uptake is tightly controlled in the presence of glucose by catabolite repression. It is desirable to construct engineered strains capable of simultaneous utilization of glucose and galactose for producing biofuels and chemicals from marine biomass. The MTH1 gene coding for transcription factor in glucose signaling was mutated in a pyruvate decarboxylase (Pdc)-deficient S. cerevisiae expressing heterologous 2,3-butanediol (2,3-BD) biosynthetic genes. The engineered S. cerevisiae strain consumed glucose and galactose simultaneously and produced 2,3-BD as a major product. Total sugar consumption rates increased with a low ratio of glucose/galactose, though, occurrence of the glucose depletion in a fed-batch fermentation decreased 2,3-BD production substantially. Through optimizing the profiles of sugar concentrations in a fed-batch cultivation with the engineered strain, 99.1 ± 1.7 g/L 2,3-BD was produced in 143 hours with a yield of 0.353 ± 0.022 g 2,3-BD/g sugars. This result suggests that simultaneous and efficient utilization of glucose and galactose by the engineered yeast might be applicable to the economical production of not only 2,3-BD, but also other biofuels and chemicals from marine biomass.

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Multi-omic characterization of laboratory-evolved Saccharomyces cerevisiae HJ7-14 with high ability of algae-based ethanol production

Kim

Lee

et al. 2018

Appl Microbiol Biotechnol

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In this study, an evolved Saccharomyces cerevisiae HJ7-14 with high ability of algae-based ethanol production was characterized by multi-omic approaches. Genome sequencing of the HJ7-14 revealed a point mutation in the GAL83 gene (G703A) involved in the catabolite repression as well as the galactose metabolism. Cultural and transcriptional analyses of a S. cerevisiae mutant with chromosomal GAL83(G703A) indicated that the catabolite repression onto the galactose metabolism was considerably relieved in all cell growth stages. Untargeted metabolomic approach revealed that metabolic phenotypes between the control D452-2 and HJ7-14 strains were clearly discriminated in time-dependent manner. Especially in early growth stage at 6 h, the HJ7-14 showed dramatic and coordinated alteration in central carbon and amino acid metabolisms. Through metabolomic re-organization, fold changes in fatty acid metabolism and metabolites related to stress response system were also found upon glucose depletion and active galactose utilization. Multi-omic characterization using genome sequencing, transcription, and metabolome profiling clearly unveiled that the GAL83 gene mutation partially relieved glucose-dependent catabolite repression and allowed the evolved HJ7-14 to efficiently convert algal sugars to ethanol. Our finding could be applicable for engineering of S. cerevisiae able to covert red algal biomass to other biofuels and biochemicals.

show abstract

Deletion of the HXK2 gene in Saccharomyces cerevisiae enables mixed sugar fermentation of glucose and galactose in oxygen-limited conditions

Cited by 14 publications

References 31 publications

Evolutionary engineering of Saccharomyces cerevisiae for efficient conversion of red algal biosugars to bioethanol

Evolutionary engineering of Saccharomyces cerevisiae for efficient conversion of red algal biosugars to bioethanol

Enhanced production of 2,3‐butanediol in pyruvate decarboxylase‐deficient Saccharomyces cerevisiae through optimizing ratio of glucose/galactose

Multi-omic characterization of laboratory-evolved Saccharomyces cerevisiae HJ7-14 with high ability of algae-based ethanol production

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