Effect of heavy water on metabolism of a symbiotic organism

The metabolism of the symbiotic organism medusomycete (tea fungus) and the influence of D2O on its development was studied by high-resolution NMR methods using isotopically enriched (by 13C and 2H) metabolites. The results demonstrate that D2O influences the selective utilization of certain protonated substrates during the formation of triose phosphates. It was found that protonated isotopomers derived from the first glucose fragment C1-C2-C3 are predominantly utilized. This explains why the metabolism slows down by a factor of 2 to 3 if D2O concentration in the medium increases. It was also shown that approximately 10% of the organisms are in the state of dynamic extracellular endosymbiosis. This state is characterized by the ability to exchange the metabolic products through close intercellular contacts. As a result of the metabolic exchange, a multicellular organism is formed, with metabolic elements localized in different partners. A distinguishing feature of this organism is the ability to accumulate the internal resources of carbon, thus making it better adapted to the unfavorable environment.