2. Research methodology
Traditional methods are limited by various technological gaps. Thus, modern methods of genetic engineering such as SDM or genome shuffling along with high-throughput screening techniques can be used to develop improved yeast strains. These methods can also be used to enhance the expression of hydrolytic enzymes to suit the SSF process. Functional genomics together with metabolic engineering can be used to develop robust yeast strains capable of fully utilizing the sugar component of LC biomass. However, construction of recombinant strains has been limited to a few species such as K. marxianus and Pichia kudriavzevii because effective genetic tools are lacking. Comparing the metabolic profiles of thermotolerant yeast and well-established mesophilic S. cerevisiae may further elucidate the thermotolerance mechanism of yeast. A combination of cold-active cellulolytic enzymes and thermotolerant yeasts can overcome the problem of different temperature optima in the SSF process. However, further research into the sugar uptake mechanism, effects of inhibitors on yeast growth, and metabolic engineering for generating co-fermenting yeasts is needed.