INVESTIGADORES
LOZADA mariana
congresos y reuniones científicas
Título:
Functional biomarker genes for the detection of PAH-degrading bacteria in coastal marine environments of Patagonia
Autor/es:
DIONISI, HEBE; LOZADA, MARIANA; MARCOS, MAGALÍ; LOVISO, CLAUDIA
Lugar:
Dalian, China
Reunión:
Congreso; BIT's 1st Annual World Congress of Petroleum Microbiology; 2010
Resumen:
<!--
/* Font Definitions */
@font-face
{font-family:SimSun;
panose-1:2 1 6 0 3 1 1 1 1 1;
mso-font-alt:"Arial Unicode MS";
mso-font-charset:134;
mso-generic-font-family:auto;
mso-font-format:other;
mso-font-pitch:variable;
mso-font-signature:1 135135232 16 0 262144 0;}
@font-face
{font-family:"\@SimSun";
panose-1:0 0 0 0 0 0 0 0 0 0;
mso-font-charset:134;
mso-generic-font-family:auto;
mso-font-format:other;
mso-font-pitch:variable;
mso-font-signature:1 135135232 16 0 262144 0;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{mso-style-parent:"";
margin:0pt;
margin-bottom:.0001pt;
text-align:justify;
mso-pagination:none;
font-size:12.0pt;
mso-bidi-font-size:10.0pt;
font-family:"Times New Roman";
mso-fareast-font-family:SimSun;
mso-font-kerning:1.0pt;
mso-ansi-language:EN-US;
mso-fareast-language:ZH-TW;}
@page Section1
{size:612.0pt 792.0pt;
margin:70.85pt 85.05pt 70.85pt 85.05pt;
mso-header-margin:36.0pt;
mso-footer-margin:36.0pt;
mso-paper-source:0;}
div.Section1
{page:Section1;}
-->
Molecular tools suitable for
providing quantitative and timely information on polycyclic aromatic
hydrocarbon (PAH) biodegradation during the bioremediation of hydrocarbon
polluted sites are greatly needed. In order to gain insight into functional
genes that could be used as biomarkers for PAH biodegradation in cold marine
environments, we targeted gene fragments encoding the large subunit of the catalytic
component of ring-hydroxylating oxygenases (RHOs). The area chosen for this study,
Ushuaia Bay, is located on the Big Island of Tierra del Fuego, Argentina, in
the southernmost tip of South America, and is chronically polluted with
hydrocarbons. We used different primer sets to amplify RHO gene fragments from
metagenomic DNA extracted from Ushuaia Bay sediments, cloned and sequenced these
amplicons. We identified 22 different groups of gene fragments, most of them
presenting low to intermediate sequence similarities with previously described
dioxygenase sequences (33 to 68% identity at the amino acid level). These
groups were also divergent among them, and were classified as belonging to
three out of the five different RHO enzyme types known up to date, indicating a
great diversity of genes related to aromatic hydrocarbon biodegradation present
in these sediments. In order to evaluate the
relative abundance of some of these novel genes in sediment samples of Ushuaia
Bay, we designed qPCR assays targeting these genes. In addition, we designed a
qPCR assay to quantify the phnA1-like
genes from the genus Cycloclasticus,
obligate marine hydrocarbonoclastic bacteria with a well established role in
aromatic hydrocarbon biodegradation, which had also been detected in sediments
of Ushuaia Bay. As a reference value and to rule out qPCR inhibition, we
quantified bacterial 16S rRNA genes using broad-specificity primers. Novel
genes were detected at levels comparable to the ones found for the phnA1 gene in polluted sediments,
suggesting that microbial populations carrying these genes could be playing an
important role in aromatic hydrocarbon biodegradation in this cold marine environment.
Further studies are being performed in this direction.