摘要
番茄红素是一种天然抗氧化剂,被应用于食品和药品等领域。传统的植物提取法和化学合成法制备番茄红素存在环境污染大、步骤繁琐、生产成本高等缺点。微生物法合成番茄红素因可有效避免以上问题而吸引了国际广泛关注。该研究在食品安全菌株枯草芽孢杆菌(Bacillus subtilis)中构建并优化了番茄红素合成途径,实现了微生物法从头合成番茄红素。首先,在B.subtilis中异源表达番茄红素合成基因簇,实现了番茄红素的从头合成;通过优化番茄红素合成基因簇中各基因的核糖体结合位点(ribosome binding sites,RBS),使番茄红素的产量提升至0.57 mg/L。此外,利用易错PCR对RBS优化后的番茄红素合成基因簇进行随机突变,获得一株番茄红素产量提升至6.4 mg/L的突变株。其次,通过筛选番茄红素合成基因簇的表达宿主,番茄红素的产量进一步提升至15.5 mg/L。在此基础上,通过强化番茄红素合成途径和敲除竞争途径,番茄红素产量达到77.4 mg/L。最终经发酵条件优化,番茄红素在摇瓶中的产量达到91.0 mg/L。该研究为微生物法合成番茄红素奠定了基础。
Lycopene is a natural antioxidant used in food and pharmaceuticals.The traditional methods of plant extraction and chemi-cal synthesis of lycopene have the disadvantages of large environmental pollution,complicated steps and high production costs.Microbial synthesis of lycopene has attracted international attention because it can effectively avoid the above problems.In this study,the lycopene synthesis pathway was constructed and optimized in food-safe strain Bacillus subtilis.Firstly,the lycopene synthesis gene cluster was heter-ogeneously expressed in B.subtilis to achieve de novo synthesis of lycopene.By optimizing the ribosome binding sites(RBS)of each gene in the lycopene synthesis gene cluster,the titer of lycopene was increased to 0.57 mg/L.In addition,error-prone PCR was used to ran-domly mutate the RBS-optimized lycopene synthesis gene cluster,and a mutant with lycopene titer increased to 6.4 mg/L was obtained.Secondly,by screening the expression host of the lycopene synthesis gene cluster,the titer of lycopene was further increased to 15.5 mg/L.On this basis,the titer of lycopene reached 77.4 mg/L by strengthening the synthetic pathway and knocking out the competitive pathway.Finally,after fine-tuning fermentation conditions,the lycopene titer in shake flasks increased to 91.0 mg/L.This study laid a foundation for the synthesis of lycopene by microbial method.
作者
王源
徐显皓
刘延峰
李江华
堵国成
吕雪芹
刘龙
WANG Yuan;XU Xianhao;LIU Yanfeng;LI Jianghua;DU Guocheng;LYU Xueqin;LIU Long(Key Laboratory of Carbohydrate Chemistry and Biotechnology,Ministry of Education,Jiangnan University,Wuxi 214122,China;Science Center for Future Foods,Jiangnan University,Wuxi 214122,China)
出处
《食品与发酵工业》
北大核心
2025年第11期12-22,共11页
Food and Fermentation Industries
基金
国家重点研发计划项目(2018YFA0900300)。
关键词
番茄红素
枯草芽孢杆菌
代谢工程
微生物发酵
发酵条件优化
lycopene
Bacillus subtilis
metabolic engineering
microbial fermentation
fermentation condition optimization
