Bacterial Outer Membrane Vesicles as Nano‐Scale Bioreactors: A Fatty Acid Conversion Case Study

Bacterial outer membrane vesicles (OMVs) are small unilamellar proteoliposomes, involved in various functions including cell‐to‐cell signalling and protein excretion. We have engineered the OMVs of Escherichia coli to nano‐scaled bioreactors for the biotransformation of fatty acids by targeting a fatty acid double bond hydratase of Stentrophomonas maltophilia (SmOhyA) and/or a photoactivated fatty acid decarboxylase from Chlorella variabilis NC64 A (CvFAP) into OMVs. Engineered OMVs containing both SmOhyA and CvFAP were able to catalyse the transformation of oleic acid ((Z)‐octadec‐9‐enoic acid) into 9‐hydroxyheptadecane via (R)‐10‐hydroxyoctadecanoic acid. The specific biotransformation rates of oleic acid reached 8.0×10−12 μmol/min per OMV. BioTrans2021: Bacterial outer membrane vesicles (OMVs) are promising nano‐scale containers for biocatalytic transformations. Here, we demonstrate their applicability to a bienzymatic cascade hydrating/decarboxylating unsaturated fatty acids.