title: Enhanced production of pigments by addition of surfactants in submerged fermentation of Monascus purpureus H1102.
abstract: BACKGROUND
  The production of pigments by Monascus spp. has attracted increasing attention. Modification of the cell membrane structure by addition of surfactants has proved to be effective for the secretion of intracellular metabolites. Hence in this study the effects and underlying mechanism of surfactants on the production of pigments in submerged fermentation of Monascus purpureus H1102 were systematically investigated.
  
  
  RESULTS
  Various surfactants exerted significant but different impacts on the biomass and production of pigments. The maximum production of pigment (304.3 U mL(-1) ) and highest extracellular/intracellular pigment ratio (1.46) were achieved when 15 g L(-1) Triton X-100 was added at 24 h of fermentation, corresponding to significant increases of 88.4 and 240% respectively compared with the control. Meanwhile, the concentration of citrinin (0.94 mg L(-1) ) was 20.6% lower than that of the control. A further study on the fatty acid composition of M. purpureus H1102 showed that the unsaturated/saturated fatty acid ratio and the index of unsaturated fatty acid increased significantly with the addition of Triton X-100.
  
  
  CONCLUSIONS
  The addition of surfactant Triton X-100 could greatly enhance the production of pigment. It was suggested that Triton X-100 facilitated the secretion of intracellular pigment and therefore enhanced pigment production accordingly.
authors.affiliation: Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
authors.forename: Yonghui
authors.initials: Y
authors.lastname: Wang
authors.forename: Bobo
authors.initials: B
authors.lastname: Zhang
authors.forename: Liping
authors.initials: L
authors.lastname: Lu
authors.forename: Yan
authors.initials: Y
authors.lastname: Huang
authors.forename: Ganrong
authors.initials: G
authors.lastname: Xu
mesh_terms: D002462:Cell Membrane / Q000737:chemistry; D002953:Citrinin / Q000032:analysis; D005227:Fatty Acids / Q000032:analysis / Q000096:biosynthesis; D005285:Fermentation / Q000187:drug effects*; D032741:Monascus / Q000187:drug effects / Q000378:metabolism*; D017830:Octoxynol / Q000494:pharmacology; D010860:Pigments, Biological / Q000096:biosynthesis*; D013501:Surface-Active Agents / Q000494:pharmacology*
chemical_list: D005227:Fatty Acids; D010860:Pigments, Biological; D013501:Surface-Active Agents; D002953:Citrinin; D017830:Octoxynol
keywords: Monascus purpureus H1102; pigment; submerged fermentation; surfactant