부산대학교 도서관

Trehalose is a reserve carbohydrate produced by Saccharomyces cerevisiae under stress conditions and used as a cryoprotectant during freeze drying. So the cellular content of trehalose is an important parameter to control in industrial context. Scale-down reactors have been used to produce Saccharomyces cerevisiae. These reactors permit to mimic the hydrodynamic conditions experienced by cells during large scale production. Three types of scale-down reactors have been tested, differing by the geometry of the non-mixed part and the recirculation flow rate. The results show that cells cultivated in scale-down reactors produced less trehalose compared to the reference reactor. These results are completed by the study of the expression of the TPS2 promoter coupled with a green fluorescent protein (GFP). TPS2 is a gene coding for a subunit of the enzymatic complex responsible of trehalose synthesis. This strain was produced in mini-bioreactors which are shake flasks equipped with a dissolved oxygen probe. This approach allows using trehalose, or related enzymes, as a cellular marker of the stress encountered by yeast in industrial process.