Russian Scientists Discovery Called into Question

Antarctica’s largest subglacial lake known as Lake Vostok is located beneath Russia’s Vostok Station, a Russian research station located at the southern Pole of Cold. The surface of Lake Vostok lies approximately 13,100 ft (4,000 m) under the ice surface. Measuring 250 km (160 mi) long by 50 km (30 mi) wide at its widest point, and covering an area of 15,690 km (6,060 sq mi) and an average depth of 344 m (1,129 ft). It has an estimated volume of 5,400 km (1,300 cu mi). The lake is divided into two deep basins by a ridge. The liquid water over the ridge is about 200 m (700 ft), compared to roughly 400 m (1,300 ft) deep in the northern basin and 800 m (2,600 ft) deep in the southern. Recently researchers found evidence of an unidentified organism in water samples brought up from Lake Vostok. The Russian team found seven samples of the mystery species in water that had frozen on a drill head used to reach the lake that lies beneath an ice sheet more than two miles (3.5km) thick. The scientists extracted strands of DNA from the organism, but said the genetic code was never more than an 86% match with any of the species listed in global databanks. Sergey Bulat, a researcher on the team at the Petersburg Nuclear Physics Institute, said that anything less than a 90% match usually indicated that the organism was unknown. But just days after Russian scientists announced that they had found a previously unidentified species of bacteria in Antarctica's subglacial Lake Vostok, the discovery has been called into question. On 9 March, the head of the genetics laboratory at the St. Petersburg Institute, Vladimir Korolyov told Interfax that what the team had found was contamination. "We found certain specimen, although not many, but all of them belonged to contaminants (microorganisms from the bore-hole kerosene, human bodies or the lab)," he said. "There was one strain of bacteria which we did not find in drilling liquid, but the bacteria could in principal use kerosene as an energy source. That is why we can't say that a previously-unknown bacteria was found." Korolyov said that they would need to wait for pure water samples to determine what, if any, life might exist in Vostok—samples that the team hopes to have within the next year.