ISOLATION AND STUDY OF PERSPECTIVE PROBIOTIC STRAIN OF SPORE-FORMING BACTERIA FROM BACILLUS GENUS

Aim. To study physiologic, biochemical as well as antagonistic characteristics of isolated strain of Bacillus pumilus in comparison with known sporeforming bacteria from B. subtilis species. Materials and methods. Four strains of Bacillus spp. were used in the study: B.subtilis 3H, B.subtilis 534, B.subtilis 1719, B.pumilus isolated from the environment. The following strains from the collection of Tarasevich State Institute of Standardization and Control for Immunobiologicals were used for determining of antagonistic activity: Staphylococcus xylosus 25, Proteus mirabilis 24a, S.aureus «Nikiforov», S.aureus «Filippov», P.vulgaris 177, Shigella flexneri 337, Escherichia coli O111:Н55, S.sonnei 170, Pseudomonas aeruginosa 9022, Candida albicans 690; clinical test-strains of yeast fungi: C.albicans (3 strains), C.haemuloni , C.tropicalis , Rhodotorula spp., Debaryomyces hansenii . Results. Identification of isolated strain on combination of morphologic, tinctorial, cultural and biochemical characteristics showed that studied strain belonged to B.pumilus species. It did not have hemolytic and lecitinase activities, was resistant to several groups of antibiotics and had index of adhesion 1.76±2.5. In experiments in vivo the strain was non-toxic, nontoxigenic and avirulent. In preparations of isolated DNA, plasmids were not found. B.pumilus had high antagonistic effect against opportunistic and pathogenic bacteria as well as yeast fungi. Comparative assessment of tested strains from Bacillus genus showed that the isolated strain was not inferior than other representatives of spore-forming bacteria on spectrum and intensity of aforementioned characteristics. Conclusion. Low-adhesive, safe, plasmid-less strain of B.pumilus , which have intensive antagonistic properties, could be considered as a candidate for the development of new probiotic drugs for medical or veterinary use.

probiotics, antagonism