Scalable preparation of silCoat‐biocatalysts by use of a fluidized‐bed reactor

Abstract

Scalable preparation of silCoat-biocatalysts by use of a fluidized-bed reactorSilCoat-biocatalysts are immobilized enzyme preparations with an outstanding robustness against leaching and mechanical stress and therefore promising tools for technical synthesis. They consist of a composite material made from a solid enzyme carrier and silicone. In this study, a method has been found to enable provision of these catalysts in large scale. It makes use of easily scalable fluidized-bed technology and, in contrast to the original method, works in almost complete absence of organic solvent. Thus, it is both a fast and safe method. When the Pt-catalyst required for silicone formation is cast on the solid enzyme carrier before coating, resulting composites resemble the original preparations in morphology, catalytic activity, and stability against leaching and mechanical forces. Only the maximum total content of silicone in the composites lies about 10% w/w lower resulting in an overall leaching stability below the theoretical maximum. When the Pt-catalyst is mixed with cooled siloxane solution before coating, surficial coating of the enzyme carriers is achieved, which provides maximum leaching stability at very low silicone consumption. Thus, the technology offers the possibility to produce both composite and for the first time also core-shell silCoat-particles, and optimize leaching stability over mechanical strength according to process requirements.

Novozym 435: the “perfect” lipase immobilized biocatalyst?

“…534 Later the coating was performed in a fluidized reactor and the Pd catalyst necessary for silicone polymerization was removed. 535 It should be expected that similar protection effects may be found using other materials used to trap some weak biocatalysts, like the crosslinked enzyme aggregates trapped in silicates, [536][537][538] in sol-gel 539 or in LentiKats (polymers of polyvinyl alcohol). 540…”

Effects of Enzyme Loading and Immobilization Conditions on the Catalytic Features of Lipase From Pseudomonas fluorescens Immobilized on Octyl-Agarose Beads

“…The most serious problem of this immobilization protocol is the risk of enzyme release under drastic conditions or in the presence of detergent-like substrates or products Hirata et al, 2016;Rios et al, 2019c;Rodrigues et al, 2019). This may be solved using different strategies, e.g., intermolecular crosslinking (physical or chemical), use of heterofunctional supports Suescun et al, 2015;Rios et al, 2019c), trapping of the enzyme in some solid matrix (Wiemann et al, 2009;Bhattacharya et al, 2012;Nieguth et al, 2017), etc. In fact, the immobilization of lipases on hydrophobic supports via interfacial activation is used for the preparations of the most popular commercial immobilized lipase biocatalysts: Novozym 435 (Ortiz et al, 2019).…”