scholarly journals Use of Mycobacterium austroafricanum IFP 2012 in a MTBE-Degrading Bioreactor

2008 ◽  
Vol 15 (2-3) ◽  
pp. 190-198 ◽  
Author(s):  
Helena Maciel ◽  
Hugues Mathis ◽  
Nicolas Lopes Ferreira ◽  
Darwin Lyew ◽  
Serge Guiot ◽  
...  
Keyword(s):  
Mycobacterium Austroafricanum

scholarly journals Biodegradation of Methyl tert-Butyl Ether and Other Fuel Oxygenates by a New Strain, Mycobacterium austroafricanum IFP 2012

2002 ◽  
Vol 68 (6) ◽  
pp. 2754-2762 ◽  
Author(s):  
Alan François ◽  
Hugues Mathis ◽  
Davy Godefroy ◽  
Pascal Piveteau ◽  
Françoise Fayolle ◽  
...  
Keyword(s):  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Dry Weight ◽  
Butyl Alcohol ◽  
Amyl Alcohol ◽  
Methyl Tert Butyl Ether ◽  
Methylotrophic Bacterium ◽  
Specific Rate ◽  
Butyl Ether ◽  
Mycobacterium Austroafricanum

ABSTRACT A strain that efficiently degraded methyl tert-butyl ether (MTBE) was obtained by initial selection on the recalcitrant compound tert-butyl alcohol (TBA). This strain, a gram-positive methylotrophic bacterium identified as Mycobacterium austroafricanum IFP 2012, was also able to degrade tert-amyl methyl ether and tert-amyl alcohol. Ethyl tert-butyl ether was weakly degraded. tert-Butyl formate and 2-hydroxy isobutyrate (HIBA), two intermediates in the MTBE catabolism pathway, were detected during growth on MTBE. A positive effect of Co2+ during growth of M. austroafricanum IFP 2012 on HIBA was demonstrated. The specific rate of MTBE degradation was 0.6 mmol/h/g (dry weight) of cells, and the biomass yield on MTBE was 0.44 g (dry weight) per g of MTBE. MTBE, TBA, and HIBA degradation activities were induced by MTBE and TBA, and TBA was a good inducer. Involvement of at least one monooxygenase during degradation of MTBE and TBA was shown by (i) the requirement for oxygen, (ii) the production of propylene epoxide from propylene by MTBE- or TBA- grown cells, and (iii) the inhibition of MTBE or TBA degradation and of propylene epoxide production by acetylene. No cytochrome P-450 was detected in MTBE- or TBA-grown cells. Similar protein profiles were obtained after sodium dodecyl sulfate-polyacrylamide gel electrophoresis of crude extracts from MTBE- and TBA-grown cells. Among the polypeptides induced by these substrates, two polypeptides (66 and 27 kDa) exhibited strong similarities with known oxidoreductases.

scholarly journals n-Alkane assimilation and tert-butyl alcohol (TBA) oxidation capacity in Mycobacterium austroafricanum strains

2007 ◽  
Vol 75 (4) ◽  
pp. 909-919 ◽  
Author(s):  
Nicolas Lopes Ferreira ◽  
Hugues Mathis ◽  
Diane Labbé ◽  
Frédéric Monot ◽  
Charles W. Greer ◽  
...  
Keyword(s):  
Butyl Alcohol ◽  
Oxidation Capacity ◽  
Tert Butyl ◽  
Tert Butyl Alcohol ◽  
Mycobacterium Austroafricanum

scholarly journals Biodegradation of 2-Ethylhexyl Nitrate by Mycobacterium austroafricanum IFP 2173

2008 ◽  
Vol 74 (20) ◽  
pp. 6187-6193 ◽  
Author(s):  
Elodie Nicolau ◽  
Lucien Kerhoas ◽  
Martine Lettere ◽  
Yves Jouanneau ◽  
Rémy Marchal
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Cetane Number ◽  
Mass Spectrometry Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Energetic Efficiency ◽  
Limiting Factor ◽  
Spectrometry Analysis ◽  
Liquid Chromatography Tandem Mass ◽  
Mycobacterium Austroafricanum

ABSTRACT 2-Ethyhexyl nitrate (2-EHN) is a major additive of fuel that is used to increase the cetane number of diesel. Because of its wide use and possible accidental release, 2-EHN is a potential pollutant of the environment. In this study, Mycobacterium austroafricanum IFP 2173 was selected from among several strains as the best 2-EHN degrader. The 2-EHN biodegradation rate was increased in biphasic cultures where the hydrocarbon was dissolved in an inert non-aqueous-phase liquid, suggesting that the transfer of the hydrophobic substrate to the cells was a growth-limiting factor. Carbon balance calculation, as well as organic-carbon measurement, indicated a release of metabolites in the culture medium. Further analysis by gas chromatography revealed that a single metabolite accumulated during growth. This metabolite had a molecular mass of 114 Da as determined by gas chromatography/mass spectrometry and was provisionally identified as 4-ethyldihydrofuran-2(3H)-one by liquid chromatography-tandem mass spectrometry analysis. Identification was confirmed by analysis of the chemically synthesized lactone. Based on these results, a plausible catabolic pathway is proposed whereby 2-EHN is converted to 4-ethyldihydrofuran-2(3H)-one, which cannot be metabolized further by strain IFP 2173. This putative pathway provides an explanation for the low energetic efficiency of 2-EHN degradation and its poor biodegradability.

scholarly journals Genes involved in the methyl tert-butyl ether (MTBE) metabolic pathway of Mycobacterium austroafricanum IFP 2012

Microbiology ◽  
2006 ◽  
Vol 152 (5) ◽  
pp. 1361-1374 ◽  
Author(s):  
Nicolas Lopes Ferreira ◽  
Diane Labbé ◽  
Frédéric Monot ◽  
Françoise Fayolle-Guichard ◽  
Charles W. Greer
Keyword(s):  
Amino Acid Sequences ◽  
Methyl Tert Butyl Ether ◽  
Peptide Fragments ◽  
Bacterial Strains ◽  
Butyl Ether ◽  
Degenerate Oligonucleotide ◽  
Molecular Masses ◽  
Dna Fragment ◽  
Mycobacterium Austroafricanum ◽  
64 Kda Protein

Methyl tert-butyl ether (MTBE) is a persistent pollutant of surface and groundwater, and the reasons for its low biodegradability are poorly documented. Using one of the rare bacterial strains able to grow in the presence of MTBE, Mycobacterium austroafricanum IFP 2012, the protein profiles of crude extracts after growth in the presence of MTBE and glucose were compared by SDS-PAGE. Ten proteins with molecular masses of 67, 64, 63, 55, 50, 27, 24, 17, 14 and 11 kDa were induced after growth in the presence of MTBE. Partial amino acid sequences of N-terminal and internal peptide fragments of the 64 kDa protein were used to design degenerate oligonucleotide primers to amplify total DNA by PCR, yielding a DNA fragment that was used as a probe for cloning. A two-step cloning procedure was performed to obtain a 10 327 bp genomic DNA fragment containing seven ORFs, including a putative regulator, mpdR, and four genes, mpdC, orf1, mpdB and orf2, in the same cluster. The MpdB protein (64 kDa) was related to a flavoprotein of the glucose–methanol–choline oxidoreductase family, and the MpdC protein (55 kDa) showed a high similarity with NAD(P) aldehyde dehydrogenases. Heterologous expression of these gene products was performed in Mycobacterium smegmatis mc2 155. The recombinant strain was able to degrade an intermediate of MTBE biodegradation, 2-methyl 1,2-propanediol, to hydroxyisobutyric acid. This is believed to be the first report of the cloning and characterization of a cluster of genes specifically involved in the MTBE biodegradation pathway of M. austroafricanum IFP 2012.

Comparison of different support materials for their capacity to immobilize Mycobacterium austroafricanum IFP 2012 and to adsorb MtBE

2007 ◽  
Vol 40 (6) ◽  
pp. 1524-1530 ◽  
Author(s):  
Darwin Lyew ◽  
Serge R. Guiot ◽  
Frédéric Monot ◽  
Francoise Fayolle-Guichard
Keyword(s):  
Support Materials ◽  
Mycobacterium Austroafricanum
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