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Citation
Tags
HERO ID
1070868
Reference Type
Journal Article
Title
Bacterial degradation of tert-amyl alcohol proceeds via hemiterpene 2-methyl-3-buten-2-ol by employing the tertiary alcohol desaturase function of the Rieske nonheme mononuclear iron oxygenase MdpJ
Author(s)
Schuster, J; Schäfer, F; Hübler, N; Brandt, A; Rosell, M; Härtig, C; Harms, H; Müller, RH; Rohwerder, T
Year
2012
Is Peer Reviewed?
Yes
Journal
Journal of Bacteriology
ISSN:
0021-9193
EISSN:
1098-5530
Volume
194
Issue
5
Page Numbers
972-981
Language
English
PMID
22194447
DOI
10.1128/JB.06384-11
Web of Science Id
WOS:000300530800008
Abstract
Tertiary alcohols, such as tert-butyl alcohol (TBA) and tert-amyl alcohol (TAA) and higher homologues, are only slowly degraded microbially. The conversion of TBA seems to proceed via hydroxylation to 2-methylpropan-1,2-diol, which is further oxidized to 2-hydroxyisobutyric acid. By analogy, a branched pathway is expected for the degradation of TAA, as this molecule possesses several potential hydroxylation sites. In Aquincola tertiaricarbonis L108 and Methylibium petroleiphilum PM1, a likely candidate catalyst for hydroxylations is the putative tertiary alcohol monooxygenase MdpJ. However, by comparing metabolite accumulations in wild-type strains of L108 and PM1 and in two mdpJ knockout mutants of strain L108, we could clearly show that MdpJ is not hydroxylating TAA to diols but functions as a desaturase, resulting in the formation of the hemiterpene 2-methyl-3-buten-2-ol. The latter is further processed via the hemiterpenes prenol, prenal, and 3-methylcrotonic acid. Likewise, 3-methyl-3-pentanol is degraded via 3-methyl-1-penten-3-ol. Wild-type strain L108 and mdpJ knockout mutants formed isoamylene and isoprene from TAA and 2-methyl-3-buten-2-ol, respectively. It is likely that this dehydratase activity is catalyzed by a not-yet-characterized enzyme postulated for the isomerization of 2-methyl-3-buten-2-ol and prenol. The vitamin requirements of strain L108 growing on TAA and the occurrence of 3-methylcrotonic acid as a metabolite indicate that TAA and hemiterpene degradation are linked with the catabolic route of the amino acid leucine, including an involvement of the biotin-dependent 3-methylcrotonyl coenzyme A (3-methylcrotonyl-CoA) carboxylase LiuBD. Evolutionary aspects of favored desaturase versus hydroxylation pathways for TAA conversion and the possible role of MdpJ in the degradation of higher tertiary alcohols are discussed.
Tags
IRIS
•
tert-Amyl ethyl ether (TAEE)
Initial Litsearch 6/2018
From PPRTV
•
n-Butanol
Database searches
WOS
•
tert-Butanol
Considered Studies
Electronic Search
•
n-Butanol
Source – January 2013 (private)
WOS - 1/2013
Merged reference set - 1/2013
Excluded (not pertinent)
Not chemical specific
•
tert-Butanol
Excluded/ Not on Topic
Biodegredation/Environmental Fate
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