title: Immobilization of Pseudomonas cepacia lipase in a phyllosilicate sol-gel matrix: effectiveness as a biocatalyst.
abstract: A novel procedure is described for immobilizing a lipase from Pseudomonas cepacia (PS-30) within a phyllosilicate sol-gel matrix. The method is based on cross-linking a phyllosilicate clay with silicate polymers produced by the controlled hydrolysis of tetramethyl orthosilicate (TMOS). The activity of the phyllosilicate sol-gel-immobilized lipase was dependent upon the type of alkylammonium salt, inorganic catalyst and volume ratio of phyllosilicate clay to TMOS used. Lipase PS-30 immobilized in this way was more stable and had higher activity compared with the free lipase. Studies on the lipase-catalysed esterification of lauric acid with octan-1-ol in iso-octane showed that under controlled water activity conditions the phyllosilicate sol-gel-immobilized lipase had better activity compared with other supported lipase preparations. In addition, the phyllosilicate sol-gel-immobilized lipase was reusable for at least five esterification cycles without significant loss of activity.
authors.affiliation: U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 E. Mermaid Lane, Wyndmoor, PA 19038, USA.
authors.forename: A F
authors.initials: AF
authors.lastname: Hsu
authors.forename: T A
authors.initials: TA
authors.lastname: Foglia
authors.forename: S
authors.initials: S
authors.lastname: Shen
mesh_terms: D002384:Catalysis; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism; D005782:Gels; D007700:Kinetics; D008049:Lipase / Q000737:chemistry* / Q000378:metabolism; D011549:Pseudomonas / Q000201:enzymology*; D012969:Sodium Fluoride / Q000737:chemistry; D014867:Water
chemical_list: D002593:Cetrimonium Compounds; D004800:Enzymes, Immobilized; D005782:Gels; D014867:Water; D012969:Sodium Fluoride; D008049:Lipase; D000077286:Cetrimonium