[Microbial synthesis of deuterium labelled L-phenylalanine with different levels of isotopic enrichment by facultative methylotrophic bacterium Brevibacterium methylicum with RMP assimilation of carbon].

The preparative microbial synthesis of amino acids labelled with stable isotopes, including deuterium ( 2 H), suitable for biomedical applications by methylotrophic bacteria was studied using L-phenylalanine as example. This amino acid is secreted by Gram-negative aerobic facultative methylotrophic bacteria Brevibacterium methylicum, assimilating methanol via ribulose-5-monophosphate (RMP) cycle of assimilation of carbon, The data on adaptation of L-phenylalanine secreted by methylotrophic bacterium В. methylicum to the maximal concentration of deuterium in the growth medium with 98% 2 Н 2 O and 2% [ 2 Н]methanol, and biosynthesis of deuterium labelled L-phenylalanine With different levels of enrichment are presented.

[Microbiological synthesis of [2H]-inosine with a high degree of isotopic enrichment by the gram-positive chemoheterotrophic bacterium Bacillus subtilis].

A 2H-labeled purine ribonucleoside inosine was microbiologically synthesized (yield, 3.9 g/L of culture liquid) using a deuterium-adapted strain ofthe gram-positive chemoheterotrophic bacterium Bacillus subtilis, cultivated in a heavy water medium with a high degree of deuteration (99.8 at % 2H) containing 2% hydrolysate of deuterated biomass of the methylotrophic bacterium Brevibacterium methylicum as a source of 2H-labeled growth substrate produced in an M9 minimal medium with 98% 2H20 and 2% [2H]-methanol.

[The biosynthesis of 2H-labelled inosine by Bacillus subtilis bacteria in a heavy-hydrogen medium].

We studied biosynthesis of the purine ribonucleoside inosine by the strain of Bacillus subtilis, which was adapted to deuterium through plating to individual colonies on 2% agar with 2H2O and subsequent selection. For growing the strain, a special heavy hydrogen medium with a high level of deuteration (89-90 at. % 2H) based on 2% hydrolyzate of the biomass of the methylotrophic Brevibacterium methylicum as a source of 2H-labeled growth substrates was obtained on 98 vol % 2H2O and 2 vol % [U-2H] methanol.

Biosynthesis of (2)H-Labeled Phenylalanine by a New Methylotrophic Mutant Brevibacterium methylicum.

The biosynthesis of (2)H-labeled phenylalanine was done by converse of low molecular weight substrates ([U-(2)H]methanol and (2)H2O) in a new RuMP facultative methylotrophic mutant Brevibacterium methylicum. To make the process work, adapted cells with improved growth characteristics were used on minimal medium M9 with the maximum content of (2)H-labeled substrates. Alanine, valine, and leucine/isoleucine were produced and accumulated exogeneously in addition to the main product of biosynthesis.