Genome of a thermophilic bacterium Geobacillus sp. TFV3 from Deception Island, Antarctica

Thermophilic microorganisms have always been an important part of the ecosystem,particularly in a hot environment,as they play a key role in nutrient recycling at high temperatures where most microorganisms cannot cope.While most of the thermophiles are archaea,thermophiles can also be found among some species of bacteria.These bacteria are very useful in the fundamental study of heat adaptation,and they are also important as potential sources of thermostable enzymes and metabolites.Recently,we have isolated a Gram-positive thermophilic bacterium,Geobacillus sp.TFV3 from a volcanic soil sample from Deception Island,Antarctica.This project was undertaken to analyze the genes of this thermophilic Antarctic bacterium and to determine the presence of thermal-stress adaptation proteins in its genome.The genome of Geobacillus sp.TFV3 was first purified,sequenced,assembled,and annotated.The complete genome was found to harbor genes encoding for useful thermal-stress adaptation proteins.The majority of these proteins were categorized under the family of molecular chaperone and heat shock protein.This genomic information could eventually provide insights on how the bacterium adapts itself towards high growth temperatures.

New Record of Black Turtle Chelonia mydas agassizii in High Latitudes of Eastern South Pacific Ocean

A juvenile specimen of the black turtle, Chelonia mydas agassizii, was located in the shores of Cabo Tamar Island in the western entrance of the Strait of Magellan, Chile. A king crab angler found the specimen, and donated it to the Río Seco Natural History Museum’s vertebrate collection for further studies and exhibition. Morphological measurements and a genetic analysis derived from an mtDNA fragment amplified and sequenced, suggest that this specimen corresponds to the species Chelonia mydas agassiizii and that it is closely related to the Galapagos Islands black turtle population. Possible influences of the El Ni？o Southern Oscillation phenomenon on this tropical species in the Eastern South Pacific Ocean are briefly discussed.

Positive interactions by cushion plants in high mountains:fact or artifact?

Positive interactions are defined as non-trophic interactions where at least one of the interacting species is benefited in terms of fitness and the other remains unaffected.Nevertheless,the bidirectional feedbacks between species may be positive,neutral or negative.Thus,if facilitated species induce negative effects on their‘nurses’,the assumed definition of positive interactions could be reconsidered.Methods We assessed if ecological interactions between cushions of Azorella madreporica and their facilitated species are positive.Specifically,we tested if cover of facilitated species has any costs for cushion plants from an ecophysiological perspective,and if these costs increase with the amount of cover of facilitated species.In addition,through pathway analysis and correlations,we assessed if cover and richness of facilitated species have a direct and/or indirect effect on the fitness of cushion plants.Important Findings We found that facilitated plant species induced a significant cost for their nurses(cushion plants),and this cost increases with cover of the facilitated species.Additionally,the facilitated species exert a strong direct negative effect on the cushion’s fitness and a moderate indirect negative cost evident through the nutrient status and physiological performance of cushion plants.We thus contribute evidence that positive interactions between high mountain cushion plants of central Chile and their‘facilitated’species may be an artifact more than a fact,especially when bidirectional effects are considered;contrasting with the majority of studies that document only one side of the interaction.