摘要
系统筛选前期构建的重组毕赤酵母基因文库,获得1株高产木聚糖酶重组菌株7-111。通过单因素试验及响应面优化试验,最终获得菌株7-111的最佳产酶条件:甲醇添加量1.4%,接种量10.7×10~8个/m L,转速303r/min。在此条件下,菌株7-111产酶量达2 235 U/m L。为进一步提高重组毕赤酵母菌株7-111产木聚糖酶的水平,对其进行高密度发酵罐试验。在生物量累积到150 g/L湿重的条件下流加低浓度甲醇,诱导产酶132 h,获得木聚糖酶产量高达8 459 U/m L,在国内外研究结果中处于较高水平。
By the means of congo-red staining and shake flask fermentation, one strain named 7-111 got a high yield of xylanase had been seleted among the gene library. The experiment of single factor test and response surface method was used to gain higher enzymatic production. The optimal conditions in this study were 1.47% methanol, 10.7×108 cells/m L initial cell content and 303 r/min shaking speed. Using these conditions the recombinant xylanase was 2 335 U/m L. In order to further studied on recombinant Pichia pastrois for producing xylanase, high density fermentation was carried out using 2.5 L fermenter. Utilizing the BSM fermented the strain 7-111 and made the cells density reach 150 g/L, then added 100% methanol to induce the enzymatic produce. At the end of the whole fermental period, we obtained a highest production of 8 459 U/m L of xylanase and the wet weight and specific activity were 302 g/L and 657.4 U/mg,respectively. The results of this study are at a high level in domestic and foreign research.
出处
《中国食品学报》
EI
CAS
CSCD
北大核心
2017年第12期95-104,共10页
Journal of Chinese Institute Of Food Science and Technology
基金
国家自然科学基金项目(31501416)
北京市自然科学基金项目(6164029)
关键词
毕赤酵母
木聚糖酶
产酶条件优化
高密度发酵
Pichia pastoris
xylanase
fermentation condition optimization
high density fermentation
