Improved xylose fermentation of Kluyveromyces marxianus at elevated temperature through construction of a xylose isomerase pathway
Improved xylose fermentation of Kluyveromyces marxianus at elevated temperature through construction of a xylose isomerase pathway
复制标题
通过构建木糖异构酶途径改进马克斯克鲁维酵母的木糖发酵
DOI：
10.1007/s10295-013-1282-6
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发表时间：
2013
影响因子：
3.4
通讯作者：
Jiong Hong
中科院分区：
文献类型：
--
作者：
Rongliang Wang;Lulu Li;Biao Zhang;Xiaolian Gao;Dongmei Wang;Jiong Hong
To improve the xylose fermentation ability of Kluyveromyces marxianus, a xylose assimilation pathway through xylose isomerase was constructed. The genes encoding xylose reductase (KmXyl1) and xylitol dehydrogenase (KmXyl2) were disrupted in K. marxianus YHJ010 and the resultant strain was named YRL002. A codon-optimized xylose isomerase gene from Orpinomyces was transformed into K. marxianus YRL002 and expressed under GAPDH promoter. The transformant was adapted in the SD medium containing 1 % casamino acid with 2 % xylose as sole carbon source. After 32 times of trans-inoculation, a strain named YRL005, which can grow at a specific growth rate of 0.137/h with xylose as carbon source, was obtained. K. marxianus YRL005 could ferment 30.15 g/l of xylose and produce 11.52 g/l ethanol with a yield of 0.38 g/g, production rate of 0.069 g/l/h at 42 °C, and also could ferment 16.60 g/l xylose to produce 5.21 g/l ethanol with a yield of 0.31 g/g, and production rate of 0.054 g/l h at 45 °C. Co-fermentation with 2 % glucose could not improve the amount and yield of ethanol fermented from xylose obviously, but it could improve the production rate. Furthermore, K. marxianus YRL005 can ferment with the corn cob hydrolysate, which contained 20.04 g/l xylose to produce 8.25 g/l ethanol. It is a good platform to construct thermo-tolerant xylose fermentation yeast.
