摘要
木糖是秸秆等纤维素类生物质原料中含量仅次于葡萄糖的第二丰富的糖,构建可高效发酵木糖的酿酒酵母菌株是提高原料利用率、降低纤维素燃料乙醇生产成本的基础.外源基因的高效表达以及本源基因的调控都需要选择表达强度合适的启动子.基于比较转录组,在全基因组水平上比较解析酿酒酵母所有基因在发酵葡萄糖、发酵木糖、发酵混合糖(葡萄糖和木糖)条件下的表达强度,拟为构建木糖利用菌株提供一系列备选的启动子库.结果表明,碳源种类对酿酒酵母启动子的强度有显著影响,绝大多数启动子强度受碳源影响显著,有67个启动子的强度在不同碳源条件下保持了相对稳定;启动子PTEF1和PTEF2、PADH1、PCCW12和某些核糖体蛋白基因启动子可在构建木糖利用菌株时作为组成型强启动子,另有中、弱强度的组成型启动子可用于基因表达优化;启动子PYNR071C、PPUT1、PDSF1等可作为利用木糖时的诱导型启动子,使基因在有需要的时候才进行表达.本研究在系统解析全基因组启动子强度和碳源种类的关系基础上,为构建利用不同碳源的酿酒酵母菌株提供了具有不同表达特征的候选启动子库.
Xylose is the second most abundant sugar in lignocellulosic biomass,but it is not a natural carbon source for Saccharomyces cerevisiae.To increase the resource utilization efficiency and reduce the cost of bioethanol production,it is crucial to construct strains able to ferment xylose effectively.The efficient expression of exogenous genes and the regulation of native genes require the selection of promotors with appropriate expression strength.However,until now,research on the strength,stability,and inducibility of promotors in S.cerevisiae,when fermenting glucose,xylose,or mixed sugars,is very limited.In this study,genome-wide transcriptome data were used to evaluate promoter strength in an industrial xyloseutilizing strain in response to four different carbon source conditions(glucose,xylose,and mixed sugars).The strength of most of the promotors changed when utilizing carbon sources other than glucose,whereas 67 promotors maintained their strength level under different sugar conditions.A series of promoter libraries were generated for genetic engineering.PTEF1,PTEF2,PADH1,PCCW12,and some ribosomal protein promotors can serve as strong constitutive promotors for xylose-utilizing strain construction.Constitutive media and weak promotors that could be used for strain optimization were summarized.PYNR071 C,PPUT1,and PDSF1 could be used as inducible promotors for xylose fermentation,driving high levels of gene expression only when necessary.The libraries of constitutive and inducible promotors with different strengths provided in this study will be useful for the genetic engineering of xylose-utilizing S.cerevisiae strains.
作者
缪晡
苟敏
陈栋
汤岳琴
MIAO Pu;GOU Min;CHEN Dong;TANG Yueqin(Sinopec Shanghai Engineering Co.Ltd.,Shanghai 200120,China;Environmental Biotechnology Research Center,College of Architecture and Environment,Sichuan University,Chengdu 610065,China;Sichuan Environmental Protection Key Laboratory of Organic Waste Resource Utilization,Chengdu 610065,China)
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2019年第5期1185-1191,共7页
Chinese Journal of Applied and Environmental Biology
基金
国家自然科学基金项目（31170093）资助~~
关键词
启动子
酿酒酵母
转录组
木糖利用
spromoter
Saccharomyces cerevisiae
transcriptome
xylose utilization
作者简介
通讯作者:汤岳琴(E-mail:tangyq@scu.edu.cn)。
