Optimized Biocatalytically Active Static Emulsions for Organic Synthesis in Nonaqueous Media

Abstract

Literature reports biocatalytically active static emulsions (BASE) as promising systems for the preparation of biocatalysts designed for synthetic use in organic media. Their excellent catalytic performance is attributed to the numerous micropools of dissolved enzymes independently dispersed in silicone beads. Here, a systematic study of the structure and morphology of BASE and optimization in terms of bead size distribution and overall catalytic performance is presented. The study relies on beads obtained by using a novel preparation method that enables a considerably improved reproducibility of the particle size and catalytic activity in separate batches. A large interfacial area of 0.023 m2 g−1 material was calculated. The adjustment of bead composition increased the apparent catalytic activity of entrapped lipase A from Candida antarctica (CalA) to 0.71 U gBASE−1, which is almost twofold higher than that previously reported. The specific activity remained in the range of prototype BASE (0.21 U mgprotein−1), which nevertheless is about 53 times higher than that reported for CalA entrapped in a sol–gel.

Lipase based static emulsions as efficient biocatalysts for biodiesel production

“…(b), the lipase‐based static emulsions retained 95.23%, 91.31%, and 84.02% of initial activity after 38 days shaking at 50 °C, 60 °C, and 70 °C, respectively. The greater stability of the lipase‐based static emulsions may be attributed to the silicone matrix that not only prevents the lipase leaching out but also weakens the strong hydraulic shear force …”

“…(b)) illustrates that numerous, small, independent droplets were dispersed in the continuous silicone phase and the diameter were 10–70 µm. This is in accordance with the results of Ansorge–Schumacher's reports …”

Enzyme–Polymer Conjugates as Robust Pickering Interfacial Biocatalysts for Efficient Biotransformations and One‐Pot Cascade Reactions

“…To explain this behavior,w ec alculated the interface area of different w/o emulsion droplets from their size and number, as characterized by CLSM (see Figures S9-S11), according to ap reviously described method. [25] Figure 3a shows that the interface area increased with the w/o ratio,w hich facilitated the mass transfer of substrates and accessibility of enzymes.T he highest BALa ctivity was reached at w/o 5:5, which created the largest contact area between the substrate and BAL. Besides the w/o ratio,t he catalytic performance was affected by the protein-polymer loading at the emulsion interface.W ith an increase in the conjugate (BAL-DP75) concentration from 10 to 40 mg mL À1 , the reaction efficiency significantly increased until it reached aplateau at 30 mg mL À1 (Figure 3b).…”

Mit Silikon zum robusten Enzym

“…Für die Emulgierung ist jedoch kein hoher Energieeintrag nötig. Die Ausdehnung der Phasenkontaktfläche wird durch das anfängliche Volumenverhältnis von Wasser zu Siloxan sowie durch die zur Emulgierung der Phasen verwendete Rührtechnik beeinflusst 13. Das bietet Spielraum für Optimierung.…”