New promising strains of <i>Bacillus subtilis</i> isolated from frozen soils of Yakutia

Abstract

Screening of natural microorganisms possessing a combination of antagonistic and enzymatic activities is one of the main tasks in the development of agrobiotechnological preparations. Microbiological studies of permafrost soils of Central Yakutia were carried out with the aim of finding bacterial strains of the Bacillus genus that are promising in modern biotechnology. 14 isolates were isolated from the middle loamy permafrost soil of the Khangalassky ulus. Of these three isolates were identified as Bacillus subtilis species by their physiological and biochemical properties which was confirmed by molecular genetic studies on 16S pPNK. The new strains of B. subtilis Bac-1p, B. subtilis Bac-2p, and B. subtilis Bac-4p were found to possess marked antagonistic properties against Salmonellosis and streptococcal pathogens: Sal. abortus equi BN-12, Str. equi 5/1. New strains are also capable of producing a number of hydrolytic enzymes (amylase, xylanase, phytase). B. subtilis TNP-3 and B. subtilis TNP-5 bacterial strains were used as controls for determining quantitative indicators of enzymatic activity. These strains are deposited in the collection of microorganisms used in animal husbandry and veterinary medicine and are the basis of probiotic preparations. B. subtilis Bac-1p, B. subtilis Bac-2p, and B. subtilis Bac-4p strains were found to be somewhat inferior to the control strains in amylolytic activity, but they were significantly superior in xylanase and phytase activities. The results of these studies have shown the potential of new B. subtilis strains for further study and the possibility of using them in the development of biological preparations for agriculture.