title: Both decrease in ACL1 gene expression and increase in ICL1 gene expression in marine-derived yeast Yarrowia lipolytica expressing INU1 gene enhance citric acid production from inulin.
abstract: In this study, some of the ATP-citrate lyase genes (ACL1) were deleted and the copy number of the iso-citrate lyase gene (ICL1) was increased in the marine-derived yeast Yarrowia lipolytica SWJ-1b displaying the recombinant inulinase. It was found that lipid content and iso-citric acid in the transformant 30 obtained were greatly reduced and citric acid production was greatly enhanced. It was also found that the ACL1 gene expression and ATP-citrate lyase activity in the transformant 30 were declined and the ICL1 gene expression and iso-citrate lyase activity were promoted. During the 2-l fermentation, 84.0 g/l of citric acid and 1.8 g/l of iso-citric acid in the fermented medium were attained from 10.0 % of inulin by the transformant 30 within 214 h. The results showed that only 0.36 % of the residual reducing sugar and 1.0 % of the residual total sugar were left in the fermented medium, suggesting that 89.6 % of the total sugar was used for citric acid production and cell growth by the transformant 30.
authors.affiliation: Unesco Chinese Center of Marine Biotechnology, Institute of Evolution and Marine Biodiversity, Ocean University of China, Yushan Road, No. 5, Qingdao, China.
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: Liu
authors.forename: Zhe
authors.initials: Z
authors.lastname: Chi
authors.forename: Guang-Lei
authors.initials: GL
authors.lastname: Liu
authors.forename: Catherine
authors.initials: C
authors.lastname: Madzak
authors.forename: Zhen-Ming
authors.initials: ZM
authors.lastname: Chi
mesh_terms: D001275:ATP Citrate (pro-S)-Lyase / Q000235:genetics / Q000378:metabolism*; D019149:Bioreactors; D053898:Biosynthetic Pathways / Q000235:genetics / Q000502:physiology*; D019343:Citric Acid / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D004926:Escherichia coli; D005285:Fermentation; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal / Q000235:genetics / Q000502:physiology*; D055786:Gene Knockout Techniques; D005822:Genetic Vectors; D007444:Inulin / Q000235:genetics / Q000378:metabolism*; D007522:Isocitrate Lyase / Q000235:genetics / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D025062:Yarrowia / Q000235:genetics* / Q000378:metabolism
chemical_list: D017931:DNA Primers; D005656:Fungal Proteins; D019343:Citric Acid; D007444:Inulin; D001275:ATP Citrate (pro-S)-Lyase; D007522:Isocitrate Lyase