title: Citric acid production from hydrolysate of pretreated straw cellulose by Yarrowia lipolytica SWJ-1b using batch and fed-batch cultivation.
abstract: In this study, crude cellulase produced by Trichoderma reesei Rut-30 was used to hydrolyze pretreated straw. After the compositions of the hydrolysate of pretreated straw were optimized, the study showed that natural components of pretreated straw without addition of any other components such as (NH4)2SO4, KH2PO4, or Mg(2+) were suitable for citric acid production by Yarrowia lipolytica SWJ-1b, and the optimal ventilatory capacity was 10.0 L/min/L medium. Batch and fed-batch production of citric acid from the hydrolysate of pretreated straw by Yarrowia lipolytica SWJ-1b has been investigated. In the batch cultivation, 25.4 g/L and 26.7 g/L citric acid were yields from glucose and hydrolysate of straw cellulose, respectively, while the cultivation time was 120 hr. In the three-cycle fed-batch cultivation, citric acid (CA) production was increased to 42.4 g/L and the cultivation time was extended to 240 hr. However, iso-citric acid (ICA) yield in fed-batch cultivation (4.0 g/L) was similar to that during the batch cultivation (3.9 g/L), and only 1.6 g/L of reducing sugar was left in the medium at the end of fed-batch cultivation, suggesting that most of the added carbon was used in the cultivation.
authors.affiliation: a Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Jiangsu Key Laboratory for Biomass-Based Energy and Enzyme Technology , Huaiyin Normal University , Huaian , China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Liu
authors.forename: Jinshun
authors.initials: J
authors.lastname: Lv
authors.forename: Tong
authors.initials: T
authors.lastname: Zhang
authors.forename: Yuanfang
authors.initials: Y
authors.lastname: Deng
mesh_terms: D002480:Cellulase / Q000737:chemistry; D002482:Cellulose / Q000737:chemistry; D019343:Citric Acid / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry; D006868:Hydrolysis; D014242:Trichoderma / Q000201:enzymology; D025062:Yarrowia / Q000254:growth & development* / Q000378:metabolism*
chemical_list: D005656:Fungal Proteins; D019343:Citric Acid; D002482:Cellulose; D002480:Cellulase
keywords: Yarrowia lipolytica SWJ-1b; batch cultivation; cellulose; citric acid; fed-batch cultivation; pretreated straw