Abstract
Pseudomonas citronellolis UAM-Ps1 co-metabolically transforms methyl tert-butyl ether (MTBE) to tert-butyl alcohol with n-pentane (2.6 mM), n-octane (1.5 mM) or dicyclopropylketone (DCPK) (4.4 mM), a gratuitous inducer of alkane hydroxylase (AlkB) activity. The reverse transcription quantitative real-time PCR was used to quantify the alkane monooxygenase (alkB) gene expression. The alkB gene was expressed in the presence of n-alkanes and DCPK and MTBE oxidation occurred only in cultures when alkB was transcribed. A correlation between the number of alkB transcripts and MTBE consumption was found (ΜΤΒΕ consumption in μmol = 1.44e−13 x DNA copies, R2 = 0.99) when MTBE (0.84 mM) was added. Furthermore, alkB was cloned and expressed into Escherichia coli and the recombinant AlkB had a molecular weight of 42 kDa. This is the first report where the expression of alkB is related to the co-metabolic oxidation of MTBE.
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Acknowledgments
We would like to thank to Paul Gaytan and Jorge Arturo Yañez from the Instituto de Biotecnología (UNAM) for DNA sequencing procedures and to the Instituto de Ciencia y Tecnología del DF (ICyTDF) for the economical support to Ana Luisa Bravo. This work was supported by research Grant 24647 from the Consejo Nacional de Ciencia y Tecnología (CONACyT).
Supporting information
Supplementary Figure 1—Standard curve for alkB quantification.
Supplementary Figure 2—Unrooted phylogenetic tree of partial (*) and complete amino acid sequences of membrane-bond alkane monooxygenases.
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Bravo, A.L., Sigala, J.C., Le Borgne, S. et al. Expression of an alkane monooxygenase (alkB) gene and methyl tert-butyl ether co-metabolic oxidation in Pseudomonas citronellolis . Biotechnol Lett 37, 807–814 (2015). https://doi.org/10.1007/s10529-014-1737-5
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DOI: https://doi.org/10.1007/s10529-014-1737-5