Effects of UV radiation on Antarctic bacteria

Project Description
The objective of this project is to analyze the effect that the incident UV
radiation has on the Antarctic bacterial flora. Two different systems will be

a) Effect on coastal marine bacteria. We will continue with experimental assays
using interferential filters in order to infer the effects of the different
wavelength bands ... (PAR, UV-A y UV-B) on the viability of the predominant
bacterial strains of the coastal marine ecosystem as well as on the bacterial
community as a whole. Assays at different deeps using the water column as a
natural UV filter will be performed. These studies will be made not only using
fixed systems but using dynamic systems too, in order to simulate the natural
vertical circulation of the water masses and the microorganisms living in such
water masses. The field studies will be complemented and compared with
laboratory assays where the bacterial isolates will be maintained under
different irradiation regimes. In all cases, bacterial viability will be
evaluated by viable counts. In addition, generation of oxygen-reactive species
will be analyzed.

b) Effect on the soil bacteria associated to Antarctic plants. It is well known
that the UV radiation induces on the vegetation a number of responses including
production of flavonoids and other UV-screen pigments. Since some authors have
reported that these compounds have biocide activity, an excess of UV radiation
could be affecting indirectly the Antarctic soils bacterial communities through
their action on the scarce vegetation. The objective of this part of the
project is to study the populations of Deschampsia antarctica and Colobanthus
quitensis in the surrounding of Jubany Station, Antarctica and to analyze if
their response to UV radiation are related to the dynamics of bacterial
communities associated to their structures.