In this issue: Biotechnology Journal 8/2010

Abstract

AbstractBiocatalyst microemulsionsPavlidis et al., Biotechnol. J. 2010, 5, 805–812Enzymes maintain their catalytic activity when hosted in aqueous nanodroplets like reverse micelles. Researchers from Ioannina, Greece, propose the use of water‐in‐ionic liquid microemulsionbased organogels (w/IL MBGs) as novel supports for the immobilization of lipase B from Candida antarctica and lipase from Chromobacterium viscosum. These novel lipase‐containing w/IL MBGs can be effectively used as solid phase biocatalysts in various polar and non‐polar organic solvents or ILs, exhibiting up to 4.4‐fold higher esterification activity compared to water‐in‐oil microemulsion‐based organogels. The immobilized lipases retain their activity for several hours at 70°C, while their half life time is up to 25‐fold higher compared to that observed in w/IL microemulsionsBiocatalyst cryogelationBieler et al., Biotechnol. J. 2010, 5, 881–885Entrapment of biocatalysts in hydrogel beads allows stable operation in otherwise deteriorating solvents. Doing this by cryogelation is a gentle method to extend the scope of biocatalysis. To foster the use of this versatile method, researchers from Aachen, Germany, devised an automated injector for the production of PVA/PEG‐enzyme immobilisates. The device consists of a thermostated reservoir connected to a programmable injector nozzle and an agitated receiving bath for the droplets. This lab‐scale production unit yields up to 1500 beads with immobilized enzyme per minute with a narrow size distribution and good roundness.Biocatalyst membrane reactorLyagin et al., Biotechnol. J. 2010, 5, 813–821Screening of biocatalysts, substrates or conditions in the early stages of bioprocess development requires an enormous number of experiments and is a tedious, expensive and time‐consuming task. Currently available screening systems can only be operated in batch or fed‐batch mode, which can lead to severe misinterpretations of screening results. Researchers from Berlin, Germany, now developed a novel screening system that enables continuous feeding of substrates and continuous removal of products. A prototype based on the membrane reactor concept was designed and operated for a model reaction, the hydrolysis of cellulose.