Molecular Genetic Characteristics of the Mutant Strain B-162/2 of the Bacteria <i>Pseudomonas chlororaphis</i> subsp. <i>aurantiaca</i>

Abstract

The production of microorganisms that produce biologically active compounds for agriculture, the chemical, veterinary and pharmaceutical industries as well as for environmental protection continues to be an important direction of microbial biotechnology. One of the most effective approaches to the production of producers is chemical mutagenesis, which, in combination with the right breeding strategy, makes it possible to obtain highly productive strains. A significant disadvantage of chemical mutagenesis is the large number of induced mutations in the genomes of mutant strains, which makes it difficult to identify genes and, accordingly, biosynthetic pathways involved in the production of a given compound. The solution to this problem is modern technologies of genome sequencing and analysis, which make it possible to identify new genes and unknown biochemical pathways involved in the formation of biologically active compounds. The aim of the work was to analyse the genome of the mutant strain B-162/2 of the bacterium Pseudomonas chlororaphis subsp. aurantiaca, which is capable of increased production of biologically active compounds of the phenazine series and is resistant to hydrogen peroxide. When analysing the genome of strain B-162/2 in full size, 6482 coding sequences and 64 coding RNA sequences were identified. Comparison of the genome of the B-162/2 strain with the genome of the wild type B-162 allowed the identification of 39 mutations, 5 of which are localised in intergenic regions, and 34 affected coding sequences. Of the mutations detected, 14 led to a radical amino acid substitution in the proteins and 2 led to the formation of premature stop codons (methyl group sensor and MFS-type transporter). Several substitutions with high values of the Grantham coefficient were found, which could possibly lead to a change in the activity of the proteins concerned. The presence of three regions with phage genes in the genome of the B-162/2 strain was detected.