CADIC   02618
CENTRO AUSTRAL DE INVESTIGACIONES CIENTIFICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Analysis of Bacterial Communities from Seawater and Marine Invertebrates from the Beagle Channel by DGGE.
Autor/es:
GOMEZ, FIORELLA F.; GUSTAVO ALEJANDRO LOVRICH; DELGADO, OSVALDO; FAUSTINO SIÑERIZ,
Lugar:
Orlando, EEUU
Reunión:
Conferencia; 106th American Association for Microbiology; 2006
Institución organizadora:
merican Association for Microbiology
Resumen:
Background: The Sea is regarded as the origin of
life on Earth and the oceans include the largest habitats on Earth hosting the
most ancient forms of life. Sub-Antarctic marine ecosystems are an important and
poorly studied source of psychrophylic and psychrotolerant microorganisms.
Denaturing Gradient Gel Electrophoresis (DGGE) is a technique that allows
assessing the structure and genetic diversity of microbial populations.
Methods: Seasonal samples were aseptically
collected at six sites from Beagle Channel, Southern
Argentina. Seawater samples were filtered trough a 0.2 µm filters.
Different culture media and conditions were assayed in order to get cultivable
microorganisms. Total DNA was extracted from seawater and from the guts of Nacella (Patinigeria) Deaurata and N. (P) magellanica, Loxechinus albus, Pseudoechinus
magallanicus, Munida subrugosa, M. gregaria, Paralomis granulosa and Lithodes
santolla. Total DNA from cultures was also studied and compared. DNA
fragments obtained by PCR were separated in denaturing gradient polyacrylamide
gels (DGGE).
Results: More UFC\ml were obtained when the
cultures were incubated at 20°C
than at 4 or 8°C.
Microbial DGGE banding patterns were different in each sample. The presence of
multiple bands demonstrated communitys variations among seawater samples and
also some seasonal bacterial population differences. There were some common
dominant bands present at more than one sampling site. The occurrence of bands
of environmental samples suggests the presence of non-culturable microorganisms
in the population when compared with amplified fragments from enrichment
cultures.
Conclusion:
The isolates from Beagle Channel, Southern Argentina
were predominantly psychrotolerant. The DGGE profile demonstrated that the bacterial
community changed along the year. Predominant common bands, single bands, will
be excised; purified, re-amplified and sequenced in order to get bacterial
identification.