- Bulk chemicals and compounds manufacturing
- Biofuel production
- More efficient use of starting materials
- More cost effective utilization of plant biomass sugars
- Improved profile of hexose – pentose co-utilization
Researchers Jay Keasling and Aindrila Mukhopadhyay of the Joint BioEnergy Institute (JBEI) have engineered a strain of Saccharomyces cerevisiae (S. cerevisiae), a commonly used yeast microbe platform, to import and metabolize xylose as a carbon source. This yeast strain is capable of utilizing both glucose and xylose when presented with plant biomass sugars, and thus allows more robust and accelerated growth.
This modified strain of S. cerevisiae is able utilize both glucose and xylose during bioproduction processes, which provides a more cost effective use of starting materials. By using pentose and hexose sugars as a carbon source, this strain of yeast is capable of producing a variety of compounds from a greater portion of the starting material.
S. cerevisiae is dominantly used in biological applications as a host microbe for the synthesis of chemical and biofuel products. Native yeast strains are unable to import xylose, and only possess a minor ability to metabolize these molecules. In order to reach co-utilization of pentose and hexose sugars, yeast cells must show both increased xylose transport and decreased glucose repression. By using known modifications that improve metabolism, and implementing several rounds of strain evolution, it was found that yeast strains with improved uptake and metabolism of xylose had a mutation in their HXT7 gene. Upon further culturing, these strains showed improvement in the co-utilization pattern of xylose and glucose in a mixed carbon medium.
DEVELOPMENT STAGE: Strains with modified HXT7(F79S) gene sequences grew substantially better on xylose-containing media when compared to unmodified parent strands.
STATUS: Patent pending. Available for licensing or collaborative research.
FOR MORE INFORMATION:
Reider-Apel, A., Ouellet M., Szmidt-Middleton H., Keasling J., Mukhopadhyay A., “Evolved hexose transporter enhances xylose uptake and glucose/xylose co-utilization in Saccharomyces cerevisiae,” Nature Sci. Rep, 6, 19512 (2016).
REFERENCE NUMBER: 2014-020