원문정보
초록
영어
Cellulosic biomass is a renewable source for biofuel productions as a non-edible biomass. In order to utilize cellulosic biomass efficiently, co-fermentation of mixed sugars (glucose and xylose) is required. Kluyveromyces marxianus is well known thermotolerent yeast which is capable of growing at 45℃ using glucose as a carbon source. However, xylose utilization is not efficient as a sole carbon source by K. marxianus. For improved xylose utilization, the mutant KmXYL1 gene coded for xylose reductase (XR) and the mutant KmXYL2 gene coded for xylitol dehydrogenase (XDH) were obtained from K. marxianus 36907-FMEL1 and K. marxianus 17694-DH1, respectively. The mutant XR from K. marxianus 36907-FMEL1 exhibited around 2 fold higher enzymatic activity that the wild type XR and the mutant XDH from K. marxianus 17694-DH1 exhibited around 65% higher enzymatic activity than the wild type XDH. When the mutant KmXYL1 was overexpressed, xylose consumption and xylitol production rates were highly increased. And the mutant KmXYL1 and KmXYL2 were overexpressed together, xylose consumption and ethanol production rates were highly increased.