Andriiash G. Preparation of Brevibacterium strains with elevated levels of lysine and threonine synthesis

The aim of the thesis - the preparation of mutant strains-producers of lysine and threonine genus Brevibacterium, the study of the biological characteristics and the definition of biosynthetic ability to enhance the strains synthesis of amino acids targeted. Objekt promising research - microbiological synthesis of the essential amino acids lysine and threonine. Research methods - microbiological (definition auxotrophy), biochemical, molecular genetic (DNA isolation, PCR), physicochemical (physical and chemical mutagenesis) and statistical processing of results. It was found after exposure to UV irradiation ability supersynthesis lysine and threonine strains Brevibacterium sp. IMV B-7447 and Brevibacterium flavum IMV B-7446, respectively. Phylogenetic analyzes of 16S rRNA gene source and mutant strains producing lysine and threonine revealed that the homology of nucleotide sequences of 16S rRNA gene starting lysine-producing strain Brevibacterium sp. 90, and a mutant strain of Brevibacterium sp. IMV B-7447 is 98%. Conducted phylogenetic analysis threonine producing strain B. flavum IMV B-7446 allowed to check its systematic position, as a consequence, the strain B. flavum IMV B-7446 belongs to the species Corynebacterium glutamicum. 16S rRNA gene sequence of strains of Brevibacterium sp. IMV B-7447 and B. flavum IMV B-7446 (C. glutamicum) is registered in the database "GenBank" (registration numbers KT151946 and KT151948, respectively). Selection of different sugars and nitrogen sources and optimization of parameters of cultivation mutant strains helped to increase the accumulation of lysine and threonine in the culture medium. Cultures deposited in the "National Depository of microorganisms," the Institute of Microbiology and Virology. DK Zabolotny NASU. Complex studies allowed to increase threonine production strain B. flavum IMV B-7446 (C. glutamicum) and lysine strain Brevibacterium sp. IMV B-7447 compared to the initial cultures in 6 and 8 times, respectively. The results are a scientific basis for the industrial producer strains of essential amino acids.