Improving xylose utilization of defatted rice bran for nisin production by overexpression of a xylose transcriptional regulator in Lactococcus lactis
Improving xylose utilization of defatted rice bran for nisin production by overexpression of a xylose transcriptional regulator in Lactococcus lactis
复制标题
通过在乳酸乳球菌中过度表达木糖转录调节因子来提高脱脂米糠的木糖利用率以生产乳链菌肽
DOI：
10.1016/j.biortech.2017.04.076
复制
发表时间：
2017
影响因子：
11.4
通讯作者：
Qiao Jianjun
中科院分区：
文献类型：
--
作者：
Liu Jiaheng;Ma Zelin;Zhu Hongji;Caiyin Qinggele;Liang Dongmei;Wu Hao;Huang Xu;Qiao Jianjun
Present investigation explores the potential of defatted rice bran (DRB) serving as sole carbon source and partial nitrogen source to supportLactococcus lactisgrowth and nisin production. To retain the nutrients in DRB, especially protein fractions, thermal pretreatment followed by enzymatic hydrolysis without washing step was applied for saccharification. A maximum of 45.64 g reducing sugar mainly containing 30.26 g glucose and 5.66 g xylose from 100 g DRB was attained in hydrolysates of DRB (HD). A novel strategy of xylR (xylose transcriptional regulator) overexpression followed by evolutionary engineering was proposed, which significantly increased the capacity ofL. lactisto metabolize xylose. Subsequently, RT-PCR results indicated that xylR overexpression stimulated expression of xylose assimilation genes synergistically with exposure to xylose. In HD medium, the highest nisin titer of the engineered strain FEXR was 3824.53 IU/mL, which was 1.37 times of that in sucrose medium by the original strain F44.
