title: Robust succinic acid production from crude glycerol using engineered Yarrowia lipolytica.
abstract: BACKGROUND
  Integrating waste management with fuels and chemical production is considered to address the food waste problem and oil crisis. Approximately, 600 million tonnes crude glycerol is produced from the biodiesel industry annually, which is a top renewable feedstock for succinic acid production. To meet the increasing demand for succinic acid production, the development of more efficient and cost-effective production methods is urgently needed. Herein, we have proposed a new strategy for integration of both biodiesel and SA production in a biorefinery unit by construction of an aerobic yeast Yarrowia lipolytica with a deletion in the gene coding succinate dehydrogenase subunit 5.
  
  
  RESULTS
  Robust succinic acid production by an engineered yeast Y. lipolytica from crude glycerol without pre-treatment was demonstrated. Diversion of metabolic flow from tricarboxylic acid cycle led to the success in generating a succinic acid producer Y. lipolytica PGC01003. The fermentation media and conditions were optimized, which resulted in 43 g L(-1) succinic acid production from crude glycerol. Using the fed-batch strategy in 2.5 L fermenter, up to 160 g L(-1) SA was yielded, indicating the great industrial potential.
  
  
  CONCLUSIONS
  Inactivation of SDH5 in Y. lipolytica Po1f led to succinic acid accumulation and secretion significantly. To our best knowledge, this is the highest titer obtained in fermentation on succinic acid production. In addition, the performance of batch and fed-batch fermentation showed high tolerance and yield on biodiesel by-product crude glycerol. All these results indicated that PGC01003 is a promising microbial factorial cell for the highly efficient strategy solving the environmental problem in connection with the production of value-added product.
authors: School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong.|State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100 People's Republic of China.|School of Life Science, Linyi University, Linyi, 276005 People's Republic of China.
authors: Cuijuan
authors: C
authors: Gao
authors: School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong.|School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, 510006 People's Republic of China.
authors: Xiaofeng
authors: X
authors: Yang
authors: School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong.
authors: Huaimin
authors: H
authors: Wang
authors: School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester, UK.
authors: Cristina Perez
authors: CP
authors: Rivero
authors: School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong.
authors: Chong
authors: C
authors: Li
authors: State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100 People's Republic of China.
authors: Zhiyong
authors: Z
authors: Cui
authors: State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100 People's Republic of China.
authors: Qingsheng
authors: Q
authors: Qi
authors: School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong.
authors: Carol Sze Ki
authors: 0000-0002-8493-4307
authors: CSK
authors: Lin
keywords: Crude glycerol; Fed-batch fermentation; Metabolic engineering; Succinic acid; Yarrowia lipolytica