Browsing by Author "Trefault, Nicole"
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Item Boletín Antártico Chileno(Instituto Antártico Chileno, 2015) Gallardo, Jorge; Espinoza, Pablo; Flores, Patricio; Muñoz, Patricio; Orlando, Julieta; Zúñiga, Catalina; Carú, Margarita; Trefault, Nicole; Rodríguez-Marconi, Susana; Montiel, Américo; Salcedo-Castro, Julio; Gamboa, Cesar; Instituto Antártico Chileno; Retamales Espinoza, JoséItem High similarity in the microbiota of cold- water sponges of the Genus Mycale from two different geographical areas(Peerj Inc, 2018-06-07) Cárdenas, César A.; González-Aravena, Marcelo; Font, Alejandro; Hestetun, Jon T.; Hajdu, Eduardo; Trefault, Nicole; Malmberg, Maja; Bongcam-Rudloff, ErikSponges belonging to genus Mycale are common and widely distributed across the oceans and represent a significant component of benthic communities in term of their biomass, which in many species is largely composed by bacteria. However, the microbial communities associated with Mycale species inhabiting different geographical areas have not been previously compared. Here, we provide the first detailed description of the microbiota of two Mycale species inhabiting the sub-Antarctic Magellan region (53 S) and the Western Antarctic Peninsula (62 64 S), two geographically distant areas (>1,300 km) with contrasting environmental conditions. The sponges Mycale (Aegogropila) magellanica and Mycale (Oxymycale) acerata are both abundant members of benthic communities in the Magellan region and in Antarctica, respectively. High throughput sequencing revealed a remarkable similarity in the microbiota of both sponge species, dominated by Proteobacteria and Bacteroidetes, with both species sharing more than 74% of the OTUs. In contrast, 16% and 10% of the OTUs were found only in either M. magellanica or M. acerata, respectively. Interestingly, despite slight differences in the relative abundance, the most dominant OTUs were present in both species, whereas the unique OTUs had very low abundances (less than 1% of the total abundance). These results show a significant overlap among the microbiota of both Mycale species and also suggest the existence of a low level of specificity of the most dominant symbiont groups.Item Isolation and characterization of an antarctic flavobacterium strain with agarase and alginate lyase activities(De Gruyter Open, 2016) Lavin, Paris; Atala, Cristian; Gallardo-Cerda, Jorge; González-Aravena, Marcelo; De la Iglesia, Rodrigo; Oses, Rómulo; Torres-Díaz, Cristian; Trefault, Nicole; Molina-Montenegro, Marco A.; Laughinghouse IV, H. DailSeveral bacteria that are associated with macroalgae can use phycocolloids as a carbon source. Strain INACH002, isolated from decomposing Porphyra (Rhodophyta), in King George Island, Antarctica, was screened and characterized for the ability to produce agarase and alginate-lyase enzymatic activities. Our strain INACH002 was identified as a member of the genus Flavobacterium, closely related to Flavobacterium faecale, using 16S rRNA gene analysis. The INACH002 strain was characterized as psychrotrophic due to its optimal temperature (17 ºC) and maximum temperature (20°C) of growth. Agarase and alginate-lyase displayed enzymatic activities within a range of 10°C to 50°C, with differences in the optimal temperature to hydrolyze agar (50°C), agarose (50°C) and alginate (30°C) during the first 30 min of activity. Strain Flavobacterium INACH002 is a promising Antarctic biotechnological resource; however, further research is required to illustrate the structural and functional bases of the enzymatic performance observed during the degradation of different substrates at different temperatures.