Viable Nematodes from Late Pleistocene Permafrost of the Kolyma River Lowland.

We have obtained the first data demonstrating the capability of multicellular organisms for longterm cryobiosis in permafrost deposits of the Arctic. The viable soil nematodes Panagrolaimus aff. detritophagus (Rhabditida) and Plectus aff. parvus (Plectida) were isolated from the samples of Pleistocene permafrost deposits of the Kolyma River Lowland. The duration of natural cryopreservation of the nematodes corresponds to the age of the deposits, 30 000-40 000 years.

[Microbial communities of ancient seeds derived from permanently frozen Pleistocene deposits].

Microbial communities from the surface of ancient seeds of higher plants and embedding frozen material dated to the late Pleistocene (formed about 30 thousand years ago) were studied by various methods: scanning electron microscopy, epifluorescence microscopy, and inoculation of nutrient media, followed by identification of isolated cultures. Both prokaryotic and eukaryotic microorganisms were found on the surface of ancient seeds. The total quantity of bacterial cells determined by direct counting and dilution plating (CFU) for the samples of ancient seeds exceeded the value in the embedding frozen material by one to two orders of magnitude. This pattern was not maintained for mycelial fungi; their quantity in the embedding material was also rather high. A significant difference was revealed between the microbial communities of ancient seeds and embedding frozen material. These findings suggest that ancient plant seeds are a particular ecological niche for microorganisms existing in permafrost and require individual detailed study.

[The possible contribution of late pleistocene biota to biodiversity in present permafrost zone]. / O vozmozhnosti uchastiia pozdnepleistotsenovoi bioty v formirovanii bioraznoobraziia sovremennoi kriolitozony.

During the last decade a wide range of biological objects, which have preserved their viability for tens and hundreds of thousands of years, was found in the samples of permafrost sediments from North-East Eurasia. Among them are bacteria, fungi, algae, moss spores, seeds of higher plants, protists. Along with physiological mechanisms of cryoconservation and constant low temperature of great importance for long-term preservation of biological objects in permafrost layers are ways of burying the organisms and conditions that prevail before the transition of sediments to the permafrost state. The analysis of viability showed by preserved biological objects gives reasons to suppose that some representatives of Pleistocene biota buried in permafrost thickness may contribute to the biodiversity of present cryolite zone.