Cloned (Comment) | Organism |
---|---|
recombinant enzyme expression in Saccharomyces cerevisiae strain CA11 (isolated from Brazilian Cachaca fermentation processes) and in strain PE-2DELTAGRE3 (isolated from Brazilian first generation bioethanol plants), coepxression with xylose reductase (XR) | Saccharomyces cerevisiae |
Protein Variants | Comment | Organism |
---|---|---|
additional information | Saccharomyces cerevisiae, the preferred microorganism for large-scale ethanol production, does not naturally consume xylose. Xylose isomerase (XI) and xylose reductase/xylitol dehydrogenase (XR/XDH) pathways are introduced into two robust industrial Saccharomyces cerevisiae strains, PE-2DELTAGRE3 and CA11, evaluated in synthetic media and corn cob hemicellulosic hydrolysate (non-detoxified corn cob hydrolysate) and the results are correlated with the differential enzyme activities found in the xylose-pathway engineered strains, evaluation of xylose fermentation capacity in oxygen-deprived conditions at 30°C and 40°C. Regarding the CA11-derived strains, the XR activity is higher in the strain with both pathways than in the one solely expressing XR/XDH, while the XDH activity at 30°C is higher in the CA11-XR/XDH strain. The sole expression of XI increases the fermentative capacity of both strains in synthetic media at 30°C and 40°C: decreasing xylitol accumulation and improving xylose consumption and ethanol production. Similar results are observed in fermentations of detoxified hydrolysate. However, in the presence of lignocellulosic-derived inhibitors, a positive synergistic effect results from the expression of both XI and XR/XDH, possibly caused by a cofactor equilibrium between the XDH and furan detoxifying enzymes, increasing the ethanol yield by more than 38%. Advantage of using the XI from Clostridium phytofermentans to attain high ethanol productivities and yields from xylose, and the simultaneous utilization of XR/XDH and XI pathways compared to the single expression of XR/XDH or XI improves ethanol production from non-detoxified hemicellulosic hydrolysates | Saccharomyces cerevisiae |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
xylitol + NAD+ | Saccharomyces cerevisiae | - |
D-xylulose + NADH + H+ | - |
r | |
xylitol + NAD+ | Saccharomyces cerevisiae ATCC 204508 | - |
D-xylulose + NADH + H+ | - |
r |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Saccharomyces cerevisiae | Q07993 | - |
- |
Saccharomyces cerevisiae ATCC 204508 | Q07993 | - |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
xylitol + NAD+ | - |
Saccharomyces cerevisiae | D-xylulose + NADH + H+ | - |
r | |
xylitol + NAD+ | - |
Saccharomyces cerevisiae ATCC 204508 | D-xylulose + NADH + H+ | - |
r |
Synonyms | Comment | Organism |
---|---|---|
XDH | - |
Saccharomyces cerevisiae |
XYL2 | - |
Saccharomyces cerevisiae |
xylitol dehydrogenase | - |
Saccharomyces cerevisiae |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
30 | - |
assay at | Saccharomyces cerevisiae |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7 | - |
assay at | Saccharomyces cerevisiae |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
NAD+ | - |
Saccharomyces cerevisiae | |
NADH | - |
Saccharomyces cerevisiae |