Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Biodegradation of 2-ethylhexyl nitrate (2-EHN) by Mycobacterium
  austroafricanum IFP 2173   2-Ethyhexyl nitrate (2-EHN) is a major additive of fuel which is used to
comply with 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 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 (NAPL), 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 GC/MS and was provisionally
identified as 4-ethyldihydrofuran-2(3H)-one by LC-MS/MS 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 metabolised
further by strain IFP 2173. This putative pathway provides an explanation for
the low energetic efficiency of 2-EHN degradation and its poor
biodegradability.

1
The categories of this paper are: cs
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
16
The categories of this paper are: stat
18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex