Heterologous production of different styrene oxide isomerases for the highly efficient synthesis of phenylacetaldehyde

A Review: The Styrene Metabolizing Cascade of Side-Chain Oxygenation as Biotechnological Basis to Gain Various Valuable Compounds

“…Finally, more than 300 mM phenylacetaldehyde (>36 g L -1 ) were obtained in this study within 60 min using this enzyme of strain Kp5.2. Remarkably, this is the highest product yield reported for this enzyme class, so far ( Oelschlägel et al, 2017 ).…”

“…This way has been initiated because recent research supposed different susceptibilities of known SOIs toward aldehyde inhibition ( Oelschlägel et al, 2014b ). This hypothesis has been proven by a more recent study in which a significantly higher stability toward product inhibition was revealed for an enzyme from S. fribergensis Kp5.2 compared to SOIs from Pseudomonas and Rhodococcus strains ( Oelschlägel et al, 2017 ). Finally, more than 300 mM phenylacetaldehyde (>36 g L -1 ) were obtained in this study within 60 min using this enzyme of strain Kp5.2.…”

“…Despite the above mentioned membrane localization, the recombinant expression of codon optimized or native styC genes in E. coli lead to a significant optimization of the producing process. Remarkably, 6- to 7-fold higher activities have been described for the enzymes from R. opacus 1CP and S. fribergensis Kp5.2 compared to the activity in the native hosts and were generated within 1–2 days ( Oelschlägel et al, 2017 ). Finally, this improved production together with the above mentioned strategies to reduce the product-mediated inhibition enhances significantly the applicability of this SOI – maybe also with respect to industrial processes.…”

“…The native reaction from styrene to phenylacetic acid by SMO, SOI and PAD ( 1 ; Oelschlägel et al, 2015a , b ; Wu et al, 2017b ) can be modified by different ways: 2 : transformation of styrenes to 2-phenylethanols by using a aldehyde reductase or alcohol dehydrogenase instead of PAD ( Wu et al, 2017a ); 3 : transformation of styrenes to 2-phenylethylamines by usage of a transaminase and L -alanine dehydrogenase instead of PAD together with host modification ( Wu et al, 2017a ). Also single reactions as epoxidation ( 4 ; e.g., Panke et al, 1998 or reviewed by Montersino et al, 2011 ), isomerization ( 5 ; Oelschlägel et al, 2017 ), and aldehyde oxidation ( 6 ; Hartmans et al, 1989 ; Crabo et al, 2017 ; Zimmerling et al, 2017 ) can be performed. The usage of other substrates is also possible: 7 : usage of glucose to yield styrene by additional usage of a phenylalanine ammonia lyase and trans -cinnamate decarboxylase ( McKenna and Nielsen, 2011 ) or 8 : to yield p -hydroxystyrene by tyrosine ammonia lyase and p -hydroxycinnamic acid decarboxylase ( Qi et al, 2007 ; Verhoef et al, 2009 ); 9 : usage of cinnamic acids to gain styrenes by additional usage of different decarboxylases ( Degrassi et al, 1995 ; Cavin et al, 1997a , b , 1998 ; Richard et al, 2015 ).…”

Enzyme‐Catalyzed Meinwald Rearrangement with an Unusual Regioselective and Stereospecific 1,2‐Methyl Shift

“…While the negative control with CFE of E. coli not expressing SOI gave only about 6 % phenylacetaldehyde, the CFE containing SOI produced α-deuterated phenylacetaldehyde 2-d 2 (MW = 122.1) with full conversion (Figure S1). The product was confirmed by the mass of the product peak in GC-MS analysis (Figure S2a) and splitting patterns (triplet for C1 and triplet of triplets for C2) arising from 13 C-2 D coupling in the proton-decoupled 13 C NMR analysis of the isolated product (Figure S2b). Therefore, these results suggest that the isomerization of 1-d 2 occurred via the proposed 1,2-D shift pathway (Figure 1a).…”