es504673j_si_001.pdf (1.16 MB)
Gene Expression of an Arthrobacter in Surfactant-Enhanced Biodegradation of a Hydrophobic Organic Compound
journal contribution
posted on 2015-03-17, 00:00 authored by Feng Li, Lizhong Zhu, Lingwen Wang, Yu ZhanSurfactants
can affect the biodegradation process and the fate
of hydrophobic organic compounds (HOCs) in the environment. Previous
studies have shown that surfactants can enhance the biodegradation
of HOCs by increasing cell surface hydrophobicity (CSH) and membrane
fluidity. In this study, we took this work one step further by investigating
the expression levels of three genes of Arthrobacter sp. SA02 in the biodegradation of phenanthrene as a typical HOC
at different concentrations of sodium dodecyl benzenesulfonate (SDBS),
which is a widely used surfactant. The Δ9 fatty acid
desaturase gene codes for Δ9 fatty acid desaturase,
which can convert saturated fatty acid to its unsaturated form. The
ring-hydroxylating dioxygenase (RHDase) and the 1-hydroxyl-2-naphthoate
dioxygenase (1H2Nase) genes code for the RHDase and
1H2Nase enzymes, respectively, which play a key role in decomposing
doubly hydroxylated aromatic compounds. The results show that these
three genes were upregulated in the presence of SDBS. On the basis
of the genetic and physiological changes, we proposed a pathway that
links the gene expression with the physiological phenomena, including
CSH, membrane fluidity, and intracellular degradation. This study
advances our understanding of the surfactant-enhanced biodegradation
of HOCs at the gene level, and the proposed pathway should be further
validated in the future.