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Engineering Saccharomyces Cerevisiae With Novel Functional Xylose Isomerases From Rumen Microbiota for Enhanced
Beatriz de Oliveira Vargas1, Marcelo Falsarella Carazzolle1, Juliana Pimentel Galhardo1
1Departamento de Genética, Evolução, Microbiologia e Imunologia, UNICAMP, Campinas, São Paulo, Brazil.
Biotechnology Journal
|June 10, 2025
Summary
Researchers discovered new xylose isomerase (XI) enzymes from rumen microbes. These enzymes efficiently convert xylose into xylulose, improving ethanol production in yeast for biofuel applications.
Area of Science:
- Microbiology
- Biotechnology
- Enzymology
Background:
- Xylose metabolism in Saccharomyces cerevisiae is hindered by the lack of efficient xylose isomerases (XI).
- Identifying novel and effective XI enzymes is crucial for optimizing industrial fermentation processes.
Purpose of the Study:
- To discover and characterize novel xylose isomerase (XI) sequences from the rumen microbiota of herbivorous mammals.
- To evaluate the efficiency of these novel XIs in converting xylose to xylulose for enhanced ethanol production in Saccharomyces cerevisiae.
Main Methods:
- Prospecting for XI sequences using metagenomic and metatranscriptomic datasets from rumen microbiota.
- Cloning and expressing seven putative XIs in a modified Saccharomyces cerevisiae strain.
- Assessing enzyme activity, substrate affinity (KM), xylose depletion rates, and ethanol yields.
Main Results:
- Five of the seven cloned XIs demonstrated activity, converting xylose to xylulose.
- A camel-derived XI showed high substrate affinity with a KM of 16.25 mM.
- Sheep-derived XIs (XI11 and XI12) achieved high xylose depletion (40 g/L) and theoretical ethanol yields (90% and 88%) in Saccharomyces cerevisiae.
Conclusions:
- Novel functional xylose isomerases were successfully identified and expressed from sheep and camel rumen microbiota in Saccharomyces cerevisiae.
- These findings significantly expand the toolkit for optimizing xylose fermentation and lignocellulosic biofuel production.
- The characterized XIs demonstrate performance comparable to benchmark enzymes, offering promising avenues for industrial applications.
