Using the DNA recombination technique, a new bacterial strain Escherichia coli DAC-22 was derived, whose cells are able to carry out the heterologous expression of Bacillus thuringiensis diadenylate cyclase – the enzyme catalyzing the reaction of adenosine-5′-triphosphate (ATP) transformation into cyclic 3′,5′-diadenylate (cyclo-di-AMP). To derive the strain, E. coli “Rosetta (DE3) pLysS” cells were originally used as recipients of plasmid pET42a+ with the inserted gene disA encoding diadenylate cyclase of B. thuringiensis. The cells of the recombinant strain are able to produce heterologous diadenylate cyclase localized predominantly (by 90 %) in the fraction of the catalytically active inclusion bodies. The productivity of the new strain with respect to diadenylate cyclase structurally arranged as the inclusion bodies was 720 units/l of cultural fluid. The inclusion bodies formed by the newly engineered strain are intended for use in the technology of producing pharmacologically promising cyclo-di-AMP.

A series of conjugates of pharmacologically promising modified nucleosides with phospholipid was synthesized. Some liponucleotides were originally produced. Soybean lecithin served as the donor of phosphatidyl residue. Phospholipase D from strain Streptomyces netropsis BIM B-428D was engaged as biocatalyst in transphosphatidylation reaction. The yield of liponucleotide synthesis reaction varied in the range 44-95 mol% depending on the acceptor of phosphatidyl residue. 65 mg (about 68 µmoles) of pure phosphatidylclofarabine was recovered by chromatography on silica gel column, resulting in 68 mol% yield calculated from the amount of modified nucleoside supplied into the reaction mixture.

Using Recombinant DNA Technology, the novel bacterial recombinant strain Escherichia coli DAC-22, a source of diadenylate cyclase that catalyzes the transformation of adenosine-5′-triphosphate into cyclic 3′,5′-diadenylate (cyclo-di-AMP), was developed. The strain was derived by the transformation of E. coli Rosetta (DE3) pLysS cells with the recombinant plasmid pET42a+ wherein the disA gene responsible for the synthesis of the diadenylate cyclase of Bacillus thuringiensis was inserted. The producing capacity of the new strain with respect to diadenylate cyclase localized in catalytically active inclusion bodies equaled 720 units per liter of liquid culture. The newly engineered strain is destined for use in the technology related to the production of pharmaceutically promising cyclo-di-AMP.