Sel’skokhozyaistvennaya Biologiya [Agricultural Biology], 2012, № 6, p. 116-121 UDK 631/635:579.64:57.088 OPTIMIZATION OF THE AFLP-FINGERPRINTING METHOD FOR A MOLECULAR-GENETIC CERTIFICATION OF AGRICULTURAL MICROORGANISMS V.I. Safronova, E.P. Chizhevskaya, E.E. Andronov All-Russia Research and Development Institute of Agricultural Microbiology, RAAS, St. Petersburg – Pushkin 196608, Russia e-mail: v.safronova@rambler.ru Received May 25, 2012 S umma r y The study involved 16 strains of the Russian collection of agricultural microorganisms (RCAM) related to the genera Bacillus, Lactobacillus, Rhizobium, and Bradyrhizobium. <...> The aim of the work was to develop a procedure of the genotypic certification of strains with AFLP-fingerprinting (amplified fragment length polymorphism), providing detection of nucleotide polymorphisms and small rearrangements. <...> As a result the protocol of AFLP-fingerprinting, ranging from the isolation of DNA from microbial cells and ending with computer data processing is developed. <...> It is shown that the method of AFLP-fingerprinting has a high specificity, resolution and reproducibility of results. <...> This method can be used to obtain individual genetic passports of microorganisms deposited in the RCAM, in order to protect the copyright of the commercial strains. <...> Scientific work on microbial culture collections involves many research programs, one of which is identification and certification of microbial cultures necessary for a safe use of microbial resources in biotechnology (including plant growing, animal husbandry, and food industry), and the copyright protection of commercial strains. <...> Today, such studies use the methods based on physiological and biochemical properties of bacterial strains and modern molecular genetic techniques, such as BOX, ERIC, REPPCR and AFLP-fingerprinting (1, 2). <...> Different variants of fingerprinting are based on the study of bacterial genomic DNA that can reveal their individual features important for documentation in strain-specific certificates. <...> AFLP-fingerprinting (amplified fragment length polymorphism) - one of the most promising methods for molecular genetic certification of microorganisms. <...> This method is based on the analysis of length polymorphism of restricted and amplified DNA fragments (3, 4). <...> High sensitivity of AFLP allows using it for identification of individual profiles of bacterial strains and distinguishing them within one species. <...> Previously, AFLPfingerprinting was successfully applied in studies of genetic differences between closely related strains of nodule bacteria belonging to different genera <...>