title: Screening of a thiamine-auxotrophic yeast for alpha-ketoglutaric acid overproduction.
abstract: OBJECTIVE
  To obtain a thiamine-auxotrophic yeast strain that overproduces alpha-ketoglutaric acid (alpha-KG) from glycerol and to investigate nutrient effects on alpha-KG production.
  
  
  RESULTS
  Yeast strain WSH-Z06, a thiamine auxotroph that gave high yields of alpha-KG from glycerol, was obtained by screening for ampicillin/kanamycin resistance and thiamine auxotrophy. The strain was identified as Yarrowia lipolytica based on physiological, chemical, and phylogenetic analysis. The ability of the strain to convert glycerol to alpha-KG was analysed by investigating the effects of nutritional factors, including thiamine, riboflavin, nitrogen sources, and calcium ion.
  
  
  CONCLUSIONS
  Thiamine and calcium ion concentration had the greatest effect on alpha-KG accumulation. Under optimal conditions, a yield of 39.2 g l(-1)alpha-KG was obtained from 100 g l(-1) glycerol, with 16.84 g l(-1) pyruvate as a by-product.
  
  
  CONCLUSIONS
  The current work provides a method for screening for an alpha-KG overproducer. Nutrients have a significant impact on alpha-KG production in the yeast strain presented here. The alpha-KG-overproducing yeast strain Y. lipolytica WSH-Z06 is a promising parent strain for further metabolic engineering to lower by-product accumulation and accelerate glycerol utilization.
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Lihu Road, Wuxi, Jiangsu, China.
authors.forename: Jingwen
authors.initials: J
authors.lastname: Zhou
authors.forename: Haiyan
authors.initials: H
authors.lastname: Zhou
authors.forename: Guocheng
authors.initials: G
authors.lastname: Du
authors.forename: Liming
authors.initials: L
authors.lastname: Liu
authors.forename: Jian
authors.initials: J
authors.lastname: Chen
mesh_terms: D002118:Calcium / Q000378:metabolism; D016000:Cluster Analysis; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D020459:Genes, rRNA; D005990:Glycerol / Q000378:metabolism*; D007656:Ketoglutaric Acids / Q000378:metabolism*; D016533:Mycological Typing Techniques; D009584:Nitrogen / Q000378:metabolism; D010802:Phylogeny; D019289:Pyruvic Acid / Q000378:metabolism; D012331:RNA, Fungal / Q000235:genetics; D012335:RNA, Ribosomal / Q000235:genetics; D012256:Riboflavin / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013831:Thiamine / Q000378:metabolism*; D025062:Yarrowia / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D004271:DNA, Fungal; D004275:DNA, Ribosomal; D007656:Ketoglutaric Acids; D012331:RNA, Fungal; D012335:RNA, Ribosomal; C065096:RNA, ribosomal, 26S; D019289:Pyruvic Acid; D009584:Nitrogen; D005990:Glycerol; D002118:Calcium; D012256:Riboflavin; D013831:Thiamine