Ammonium acrylate biomanufacturing by an engineered Rhodococcus ruber with nitrilase overexpression and double-knockout of nitrile hydratase and amidase

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• 作者：Jizhe Sun ; Huimin Yu ; Jie Chen ; Hui Luo…
• 关键词：Biomanufacturing of ammonium acrylate ; NHase ; amidase double ; knockout ; Nitrilase overexpression ; Cell catalysts ; Engineered cells of R. ruber
• 刊名：Journal of Industrial Microbiology and Biotechnology
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：43
• 期：12
• 页码：1631-1639
• 全文大小：1,029 KB
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Chemistry
  Biotechnology
  Genetic Engineering
  Biochemistry
  Bioinformatics
  Microbiology
  Microbial Genetics and Genomics
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：1476-5535
• 卷排序：43

文摘

Rhodococcus ruber TH was selected as a parent strain to engineer for biomanufacturing of ammonium acrylate; the characteristics of this strain included accelerated growth rate, high cell tolerance and natively overexpressed nitrile hydratase (NHase). Transcriptome analysis revealed that the transcription levels of the native NHase, amidase and nitrilase were extremely high, moderate and extremely low, respectively. Through NHase-amidase double-knockout and amidase single-knockout, the engineered strains R. ruber THdAdN and R. ruber THdA were obtained for overexpression of a heterologous nitrilase from R. rhodochrous tg1-A6 using a urea-induced Pa2 promoter. The nitrilase activity toward substrate acrylonitrile in the engineered THdAdN(Nit) reached 187.0 U/mL at 42 h, threefold of that R. rhodochrous tg1-A6 and 2.3-fold of that of THdA(Nit). The optimal catalysis temperature and pH of the nitrilases in different cells exhibited no significant difference. Using the cells as catalysts, biomanufacturing of ammonium acrylate was performed under room temperature. When catalyzed by the engineered THdAdN(Nit), the titer and productivity of ammonium acrylate dramatically increased to 741.0 g/L and 344.9 g/L/h, which are the highest results reported to date.