Draft Genome of Shewanella frigidimarina Ag06-30, a Marine Bacterium Isolated from Potter Peninsula, King George Island, Antarctica.

We present the draft genome of Shewanella frigidimarina Ag06-30, a marine bacterium from King George Island, Antarctica, which encodes the carbapenemase SFP-1. The assembly contains 4,799,218 bp (G+C content 41.24%). This strain harbors several mobile genetic elements that provide insight into lateral gene transfer and bacterial plasticity and evolution.

Molecular characterisation of anthropogenic sources of sedimentary organic matter from Potter Cove, King George Island, Antarctica.

Although relatively recent, human activities in Antarctica, such as growing tourism, fishery activities, and scientific operations, have affected some areas of this continent. These activities eventually release pollutants, such as petroleum and its derivatives and sewage, into this environment. Located on King George Island (25 de Mayo Island), Potter Cove (62°14'S, 58°39'W) is home to the Argentine Carlini research station. To evaluate the anthropogenic impacts surrounding Potter Cove, sediment samples were collected and analysed for sewage and fuel introduction via the determination of organic markers. The highest concentrations were found in the central portion of the fjords, where fine sediments are deposited and the accumulation of organic molecules is favoured. Aliphatic hydrocarbons were mainly derived from biogenic sources, evidenced by the predominance of odd short-chain n-alkanes. Anthropogenic impacts were evidenced primarily by the presence of PAHs, which were predominantly related to petrogenic sources, such as vessel and boat traffic. Sewage marker concentrations were much lower than those found in other Antarctic regions. These results indicate that oil hydrocarbons and sewage inputs to Potter Cove may be considered low or only slightly influential.

Extracellular proteases from eight psychrotolerant Antarctic strains.

Extracellular proteases from 8 Antarctic psychrotolerant Pseudomonas sp. strains were purified and characterised. All of them are neutral metalloproteases, have an apparent molecular mass of 45kDa, optimal activity at 40 degrees C and pH 7-9, retaining significant activity at pH 5-11. With the exception of P96-18, which is less stable, all retain more than 50% activity after 3 h of incubation at pH 5-9 and show low thermal stability (their half-life times range from 20 to 60 min at 40 degrees C and less than 5 min at 50 degrees C). These proteases can be used in commercial processes carried out at neutral pH and moderate temperatures, and are of special interest for their application in mixtures of enzymes where final thermal selective inactivation is needed. Results also highlight the relevance of Antarctic biotopes for the isolation of protease-producing enzymes active at low temperatures.