Phenomenon of Biological Adaptation to Heavy Water

Abstract

Biological influence of deuterium oxide to cells of various taxonomic groups of prokaryotic and eucaryotic microorganisms realizing methylotrophic, chemoheterotrophic, photo-organotrophic, and photosynthetic ways of assimilation of carbon substrates (methylotrophic bacteria Brevibacterium methylicum, chemoheterotrophic bacteria Bacillus subtilis, photo-organotrophic halobacteria Halobacterium halobium, and single sell green algae Chlorella vulgaris) was investigated at the growth on media with ²H₂O. For investigated microorganisms are submitted the data on growth and adaptation on the growth media containing as sources of deuterated substrates ²H₂O, [²H]methanol and hydrolisates of deutero-biomass of methylotrophic bacteria B. methylicum, obtained after multistage adaptation to ²H₂O. The qualitative and quantitative composition of intra- and endocellular amino acids, proteins, carbohydrates and fatty acids in conditions of adaptation to ²H₂O is investigated. It is demonstrated that the effects observed at adaptation to ²H₂O, possess a complex multifactorial character and connected to cytological, morphological and physiological changes – the magnitude of the lag- period, time of cellular generation, output of biomass, a parity ratio of synthesized amino acids, proteins, carbohydrates and lipids, and also with an evolutionary level of the organization of the investigated object and the pathways of assimilation of carbon substrates as well. These data suggest that adaptation to deuterium oxide is a multifactorial phenomenon, affecting many cellular systems, as biosynthesis of macromolecules, metabolism, transport functions of cells.

Key words: deuterium, deuterium oxide, adaptation, isotopic effects, bacteria, micro algae.