title: Encapsulation of synthetically valuable biocatalysts into polyelectrolyte multilayer systems.
abstract: Layer-by-Layer (LbL) technology recently turned out to be a versatile tool for the encapsulation of bioactive entities. In this study, the factual potential of this technology to encapsulate synthetically valuable biocatalysts, that is enzymes and whole cells expressing a specific catalytic activity, was investigated. The biocatalysts were embedded into a polyelectrolyte multilayer system involving poly(allylamine) hydrochloride (PAH) and poly(styrene sulfonate) sodium salt (PSS). The enzymes were adsorbed to CaCO3 or DEAE-cellulose previous to encapsulation. A slight increase (32%) of the catalytic performance was observed for lipase B from Candida antarctica when four layers of polyelectrolytes were applied. On the whole, however, the residual activity of the investigated enzymes after encapsulation was rather low. Similar results were obtained with whole-cell biocatalysts. It was found that the activity decrease can be attributed to mass transfer restrictions as well as direct interactions between polyelectrolytes and catalytically active molecules. Both effects need to be understood in more detail before LbL technology can be advanced to technically efficient biocatalysis.
authors.affiliation: RWTH Aachen UniVersity, Department of Biotechnology, Worringerweg 1, D-52074 Aachen, Germany.
authors.forename: Lars O
authors.initials: LO
authors.lastname: Wiemann
authors.forename: Andreas
authors.initials: A
authors.lastname: Buthe
authors.forename: Mathias
authors.initials: M
authors.lastname: Klein
authors.forename: Anne
authors.initials: A
authors.lastname: van den Wittenboer
authors.forename: Lars
authors.initials: L
authors.lastname: Dähne
authors.forename: Marion B
authors.initials: MB
authors.lastname: Ansorge-Schumacher
mesh_terms: D055162:Biocatalysis; D002119:Calcium Carbonate / Q000737:chemistry; D002175:Candida / Q000201:enzymology; D003102:Colloids; D008049:Lipase / Q000378:metabolism*
chemical_list: D003102:Colloids; D008049:Lipase; D002119:Calcium Carbonate