| Title |
Systematic optimization of gene expression of pentose phosphate pathway enhances ethanol production from a glucose/xylose mixed medium in a recombinant Saccharomyces cerevisiae
|
|---|---|
| Published in |
AMB Express, August 2018
|
| DOI | 10.1186/s13568-018-0670-8 |
| Pubmed ID | |
| Authors |
Yosuke Kobayashi, Takehiko Sahara, Satoru Ohgiya, Yoichi Kamagata, Kazuhiro E. Fujimori |
| Abstract |
The pentose phosphate pathway (PPP) plays an important role in the synthesis of ribonucleotides and aromatic amino acids. During bioethanol production from cellulosic biomass composed mainly of D-glucose and D-xylose, the PPP is also involved in xylose metabolism by engineered Saccharomyces cerevisiae. Although the activities and thermostabilities of the four PPP enzymes (transaldolase: TAL1, transketolase: TKL1, ribose-5-phosphate ketol-isomerase: RKI1 and D-ribulose-5-phosphate 3-epimerase: RPE1) can affect the efficiency of cellulosic ethanol production at high temperatures, little is known about the suitable expression levels of these PPP genes. Here, we overexpressed PPP genes from S. cerevisiae and the thermotolerant yeast Kluyveromyces marxianus either singly or in combination in recombinant yeast strains harboring a mutant of xylose isomerase (XI) and evaluated xylose consumption and ethanol production of these yeast transformants in glucose/xylose mixed media at 36 °C. Among the PPP genes examined, we found that: (1) strains that overexpressed S. cerevisiae TKL1 exhibited the highest rate of xylose consumption relative to strains that overexpressed other PPP genes alone; (2) overexpression of RKI1 and TAL1 derived from K. marxianus with S. cerevisiae TKL1 increased the xylose consumption rate by 1.87-fold at 24 h relative to the control strain (from 0.55 to 1.03 g/L/h); (3) the strains with XI showed higher ethanol yield than strains with xylose reductase and xylitol dehydrogenase and (4) PHO13 disruption did not improve xylose assimilation under the experimental conditions. Together these results indicated that optimization of PPP activity improves xylose metabolism in genetically engineered yeast strains, which could be useful for commercial production of ethanol from cellulosic material. |
X Demographics
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Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Unknown | 2 | 100% |
Demographic breakdown
| Type | Count | As % |
|---|---|---|
| Members of the public | 2 | 100% |
Mendeley readers
The data shown below were compiled from readership statistics for 67 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Unknown | 67 | 100% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Student > Ph. D. Student | 10 | 15% |
| Student > Bachelor | 9 | 13% |
| Student > Master | 6 | 9% |
| Researcher | 5 | 7% |
| Professor > Associate Professor | 5 | 7% |
| Other | 10 | 15% |
| Unknown | 22 | 33% |
| Readers by discipline | Count | As % |
|---|---|---|
| Biochemistry, Genetics and Molecular Biology | 21 | 31% |
| Agricultural and Biological Sciences | 11 | 16% |
| Chemical Engineering | 2 | 3% |
| Nursing and Health Professions | 2 | 3% |
| Environmental Science | 1 | 1% |
| Other | 6 | 9% |
| Unknown | 24 | 36% |
Attention Score in Context
This research output has an Altmetric Attention Score of 1. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 29 August 2018.
All research outputs
#18,648,325
of 23,102,082 outputs
Outputs from AMB Express
#808
of 1,245 outputs
Outputs of similar age
#257,297
of 334,958 outputs
Outputs of similar age from AMB Express
#19
of 52 outputs
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