Immobilization of an integral membrane protein for biotechnological phenylacetaldehyde production

Production of a recombinant membrane protein in an Escherichia coli strain for the whole cell biosynthesis of phenylacetic acids

“…1). This recombinant specific activity corresponds to our knowledge to the highest SOI activity ever reported for crude cell extracts of SOI-containing wild-type strains [16], [19], [30], [34], [35]. In contrast to the cultivation in battled flasks, culture volume was significantly extended from 25 ml to 4 l. Thus, in total 2380 mg ± 262 mg protein and 106,100 ± 9200 U of SOI were obtained after in total 10 h applying strain BL21(DE3) pLysS pET16bP- styC in the fermenter.…”

“…The cultivation of strain 1CP was performed in the same fermenter containing also 4 l of medium. In the former study, a total SOI activity of 18,000 U and in total about 1000 mg protein were obtained which corresponds to a specific SOI activity of only 18 U mg −1 [34]. Furthermore, the cultivation time of this Rhodococcus strain was significantly longer and the production of active biomass needed 28 days.…”

“…In contrast to the cultivation in battled flasks, culture volume was significantly extended from 25 ml to 4 l. Thus, in total 2380 mg ± 262 mg protein and 106,100 ± 9200 U of SOI were obtained after in total 10 h applying strain BL21(DE3) pLysS pET16bP- styC in the fermenter. A previous study has reported the production of a wild-type SOI in R. opacus 1CP [34]. The cultivation of strain 1CP was performed in the same fermenter containing also 4 l of medium.…”

“…The isomerization of styrene oxide can be catalyzed by acetic zeolite [15], alkali-treated silica alumina [46], hydrotalcite-derived basic solids [22], or titanium-containing synthetic zeolite [29] beside others. Biotechnological processes of phenylacetaldehyde synthesis have been described by several previous studies, e.g., applying a cell-free styrene oxide isomerase (SOI) in presence of styrene oxide [27], [32], [34] or whole cells of Gluconobacter or Acetobacter strains for the transformation of 2-phenylethanol [5], [28].…”

“…These enzymes are involved in the microbiological styrene degradation and convert styrene oxide into phenylacetaldehyde [16], [19], [27], [31], [32]. Despite of the high SOI activities in some wild-type strains [35] the production of SOIs by these strains is very time-consuming [34]. This aspect and the inhibition of these enzymes by their product at higher concentrations [32], [35] limits their application and need further optimization.…”