[Temperature as a factor of development of psychrotolerant mycelial bacteria complexes in soils of north regions]

It has been demonstrated that complexes of mycelial bacteria (actinomycetes), in which the amount of psychrotolerant actinomycetes reaches hundreds of thousands of CFU/g of the soil (frequently exceeding the portion of mesophilic forms), are developed in peat and podzolic soils of the tundra and taiga at low temperatures. As actinomycetes grow and develop in cold soils, their mycelium increases in length. Use of the molecular in situ hybridization method (fluorescent in situ hybridization, FISH) demonstrated that the portion of metabolically active mycelial actinobacteria exceeds the portion of unicellular actinobacteria in the Actinobacteria phylum. Specific peculiarities of psychrotolerant populations in relation to the spectrum of consumed substrates (histidine, mannitol, saccharose) were established by the method of multirespirometric testing.