Toward The Science Of Candida Maltosa For Sugar Transporter

Sugar transporter is a responsibility to absorb nutrient substance and to open the cycle of sugar metabolism as a kind of membrane protein. They play a key role of energy conservation and carbon balance. This paper mainly research characteristic of sugar transporter by gene prediction and annotation, functional complementation and fermentation testing using the Candida maltosa Xu316which can efficiently converting xylose to xylitol and ethanol. First revealed the properties of gene sequence and function of sugar transporters.Initially, the number of5,497contigs are acquired by sequencing and assembly from Candida maltosa Xu316. Subsequently, totally5,992proteins are predicted and annotated by the software of FgeneSH and UniRef90, KEGG databases. We are screened out23putative sugar transporters as the materials of functional testing.Moreover, we need test function of23putative sugar transporters after cloning and construct plasmids and transform to Saccharomyces cerevisiae EBY.VW4000and ability of xylose metabolism in Saccharomyces cerevisiae Xyl from construction ourselves, T1, T2, T3, T15, T17are proved functional sugar transporter by2%and10%glucose and high concentration of glucose can depress the transport capability. This research also observed that sugar transporters have different affinity with each monosaccharides when they evaluate the functional complementation strain to utilize carbon source of xylose, fructose, galactose, mannose respectively via the measure of growth ability rate.Lastly, we evaluate the fermentation capability of5sugar transporters as a carbon of2%glucose, xylose, fructose, galactose, mannose. From the serious of consequences, the efficient glucose transporter are Tl and T3which the glucose consumption rate are reach1.6g L-1h-1、1.4g L-1h-1which are efficiently glucose transporter are screened, meanwhile, they also can utilize xylose, and the growth rates are increase14times than initial period. In the research of mix sugars related glucose and xylose(1:1), a regular is that the xylose consumption efficiency is effect of the initial cell concentration, the other respect of the property are accord with the pure substrate of glucose or xylose. The fructose is efficiently transported by sugar transpoter T1, the capability of mannose and galactose transporters are sugar transporter T17, the yield rate of ethanol respectively reach64.7%,60.2%,62.7%. The capability of sugar transporter is positive correlation with specific growth rate, sugar consumption rate and the ethanol yield.In the application, screened efficient sugar transporters have a significant role which can boost the mix sugar utilization.