(418ca) Does Saccharomyces Cerevisiea TSH1 Possess the Properties Particularly Suitable for Solid-State Fermentation of Sweet Sorghum Ethanol Compared to Industrial Yeast Strains

With the increasing concerns over cost-effective and environmental friendly production of biofuels, the great potential of solid-state fermentation (SSF) in biofuels area has been recognized recently, due to relatively simple production process and very little disposal of wastewater compared to submerged liquid fermentation (SLF). Over the past several years we developed the advanced solid-state fermentation (ASSF) for fuel ethanol production from sweet sorghum stalks from bench up to industrial scale (500 m3), which overcomes fundamental constraints of traditional SSF ,exhibiting a high ethanol productivity comparable to SLF. Most recently, we have run a 500-m3 continuous ASSF for sweet sorghum ethanol production in China, firstly verifying the feasibility of SSF’s application at industrial scale. Saccharomyces cerevisiae TSH1 used during the process, is capable of completing sugars utilization within 24 h during the SSF using sweet sorghum containing a total sugar content of 10~14% (w/w), with a 91% of theoretical ethanol yield. In a previous study, we characterized ethanol producer TSH1’s physiological and biochemical properties with a lab yeast strain as the reference. The outcome showed that TSH1 exhibits obvious advantages against the lab strain, including higher growth rate, ethanol productivity, and stronger tolerance to inhibitors. These results motivated our interest in evaluating whether TSH1 possesses special properties suitable for SSF compared to industrial yeast strains. In this study, we focused on characterizing TSH1 and several other industrial yeast strains and compared the fermentation performances of these strains under various conditions. This study is aimed to provide an insight into the mechanism of microorganism behavior in SSF, finally harnessing the untapped potentials of SSF for the application in biofuels production.