8-56: Molecular cloning and characterization of two novel fructose-specific transporters from an osmotolerant and fructophilic yeast Candida magnoliae JH110

Sugar transport is very critical in developing an efficient and rapid conversion process of a mixture of sugars by engineered microorganisms. Here, we identified two novel fructose-specific transporters, CmFSY1 and CmFRT1 from an osmotolerant and fructophilic yeast Candida magnoliae JH110. Heterologous expression of two fructose transporter genes in Saccharomyces cerevisiae unable to utilize hexoses unveiled that both transporters are functionally expressed and specifically transport fructose. These results are further corroborated by kinetic analysis of fructose transport that elucidates the CmFsy1p is a high-affinity fructose-specific transporter with low capacity (K_M = 0.13 ± 0.01mM, V_max = 2.1 ± 0.3mmol h^-1 g^-1) and the CmFrt1p is a low-affinity fructose-specific transporter with high capacity (K_M = 105 ± 12mM, V_max = 8.6 ± 0.7mmol h^-1 g^-1).These fructose-specific transporters can be used for improving fructose transport in recombinant microorganisms for production of biofuels and chemicals from fructose-containing feedstock.