Applied Microbiology and Biotechnology

, Volume 97, Issue 3, pp 1131–1140

Substrate range and enantioselectivity of epoxidation reactions mediated by the ethene-oxidising Mycobacterium strain NBB4

Biotechnologically relevant enzymes and proteins


Mycobacterium strain NBB4 is an ethene-oxidising micro-organism isolated from estuarine sediments. In pursuit of new systems for biocatalytic epoxidation, we report the capacity of strain NBB4 to convert a diverse range of alkene substrates to epoxides. A colorimetric assay based on 4-(4-nitrobenzyl)pyridine) has been developed to allow the rapid characterisation and quantification of biocatalytic epoxide synthesis. Using this assay, we have demonstrated that ethene-grown NBB4 cells epoxidise a wide range of alkenes, including terminal (propene, 1-butene, 1-hexene, 1-octene and 1-decene), cyclic (cyclopentene, cyclohexene), aromatic (styrene, indene) and functionalised substrates (allyl alcohol, dihydropyran and isoprene). Apparent specific activities have been determined and range from 2.5 to 12.0 nmol min−1 per milligram of cell protein. The enantioselectivity of epoxidation by Mycobacterium strain NBB4 has been established using styrene as a test substrate; (R)-styrene oxide is produced in enantiomeric excesses greater than 95%. Thus, the ethene monooxygenase of Mycobacterium NBB4 has a broad substrate range and promising enantioselectivity, confirming its potential as a biocatalyst for alkene epoxidation.


Biocatalysis Epoxidation Alkene Mycobacterium Soluble di-iron monooxygenase Non-heme iron Oxidation 

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Samantha Cheung
    • 1
    • 2
  • Victoria McCarl
    • 2
  • Andrew J. Holmes
    • 2
  • Nicholas V. Coleman
    • 2
  • Peter J. Rutledge
    • 1
  1. 1.School of ChemistryThe University of SydneySydneyAustralia
  2. 2.School of Molecular BioscienceThe University of SydneySydneyAustralia

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