Study paves way to more efficient production of 2G ethanol using specially modified yeast strain
A Brazilian study paves the way to increased efficiency of second-generation (2G) ethanol production based on the discovery of novel targets for metabolic engineering in a more robust strain of industrial yeast. An article on the study is published in the journal Scientific Reports.
The databases compiled by the authors are at the disposal of the scientific community in the repository of the State University of Campinas (UNICAMP), which is a member of the Dataverse Project, an international collaborative initiative.
First-generation (1G) ethanol is produced from sources rich in carbohydrates (such as sucrose), especially sugarcane in the Brazilian case. Processing of sugarcane generates large amounts of fibrous residues, such as bagasse, which can be used to produce steam and electricity in power plants. These residues are rich in cellulose and hemicellulose (polymeric carbohydrates that maintain the mechanical strength of plant stem cell walls), which can be used to produce 2G ethanol via conversion into smaller molecules for fermentation by yeast and other microorganisms.
The main challenge in 2G ethanol production is conversion efficiency since cellulose and hemicellulose are hard to hydrolyze. The first step has to be the removal of tough, stringy lignin, which is basically fiber, to make the simple sugars located in the cellulose and hemicellulose available to the yeast. This is costly, consumes a great deal of energy, and releases substances that can inhibit the fermentation process.
“2G ethanol production still requires optimization to increase efficiency. One of the approaches needed entails the identification of yeast strains that resist spoilage by inhibitory molecules derived from the processing of these residues,” said Marcelo Mendes Brandão, last author of the article and a researcher at UNICAMP’s Center for Molecular Biology and Genetic Engineering (CBMEG). “Some industrial yeast strains are known to have higher levels of tolerance of these compounds. A well-documented example is Saccharomyces cerevisiae SA-1, a Brazilian industrial strain for fuel ethanol that has shown high resistance to inhibitors produced by the pretreatment of cellulosic complexes. This strain was the focus of our study.”
Source Link: https://phys.org/news/2023-03-paves-efficient-production-2g-ethanol.html
