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Bacillus velezensis strains are applied as ecologically safe biopesticides, plant growth promoting rhizobacteria (PGPR), and in veterinary probiotics. They are abundant in various environments including soil, plants, marine habitats, the intestinal micro-flora, etc. The mechanisms underlying this adaptive plasticity and bioactivity are not well understood, nor is it clear why several strains outperform other same species isolates by their bioactivities. The main objective of this work was to demonstrate versatility of bioactivities and lifestyle strategies of the selected B. velezensis strains suitable to serve as model organisms in future studies. Here, we performed a comparative study of newly sequenced genomes of four B. velezensis isolates with distinct phenotypes and isolation origin, which were assessed by RNA sequencing under the effect of root exudate stimuli and profiled by epigenetic modifications of chromosomal DNA. Among the selected strains, UCMB5044 is an oligotrophic PGPR strain adapted to nutrient poor desert soils. UCMB5113 and At1 are endophytes that colonize plants and require nutrient rich media. In contrast, the probiotic strain, UCMB5007, is a copiotroph, which shows no propensity to colonize plants. PacBio and Illumina sequencing approaches were used to generate complete genome assemblies, tracing epigenetic modifications, and determine gene expression profiles. All sequence data was deposited at NCBI. The strains, UCMB5113 and At1, show 99% sequence identity and similar phenotypes despite being isolated from geographically distant regions. UCMB5007 and UCMB5044 represent another group of organisms with almost identical genomes but dissimilar phenotypes and plant colonization propensity. The two plant associated strains, UCMB5044 and UCMB5113, share 398 genes putatively associated with root colonization, which are activated by exposure to maize root exudates. In contrast, UCMB5007 did not respond to root exudate stimuli. It was hypothesized that alterations in the global methylation pattern and some other epigenetic modifications enable adaptation of strains to different habitats and therefore may be of importance in terms of the biotechnological applicability of these bacteria. Contrary, the ability to grow on root exudates as a sole source of nutrients or a strong antagonism against phytopathogens showed by the strains in vitro cannot be considered as good predictors of PGPR activities., (Copyright © 2019 Reva, Swanevelder, Mwita, David Mwakilili, Muzondiwa, Joubert, Chan, Lutz, Ahrens, Avdeeva, Kharkhota, Tibuhwa, Lyantagaye, Vater, Borriss and Meijer.)

We studied the effect of genetic transformation on biologically active compound (artemisinin and its co-products (ART) as well as sugars) accumulation in Artemisia vulgaris and Artemisia dracunculus "hairy" root cultures. Glucose, fructose, sucrose, and mannitol were accumulated in A. vulgaris and A. dracunculus "hairy" root lines. Genetic transformation has led in some cases to the sugar content increasing or appearing of nonrelevant for the control plant carbohydrates. Sucrose content was 1.6 times higher in A. vulgaris "hairy" root lines. Fructose content was found to be 3.4 times higher in A. dracunculus "hairy" root cultures than in the control roots. The accumulation of mannitol was a special feature of the leaves of A. vulgaris and A. dracunculus control roots. A. vulgaris "hairy" root lines differed also in ART accumulation level. The increase of ART content up to 1.02 mg/g DW in comparison with the nontransformed roots (up to 0.687 mg/g DW) was observed. Thus, Agrobacterium rhizogenes-mediated genetic transformation can be used for obtaining of A. vulgaris and A. dracunculus "hairy" root culture produced ART and sugars in a higher amount than mother plants.

Dysbiotic conditions prevail in both humans and animals. Intestinal dysbiosis is accompanied, in addition to the quantitative and qualitative changes of the microflora, by immunosuppression and metabolic disorders, such as avitaminosis А. Therefore, the search and study of microorganism strains, which may be used for correction of dysbiosis and allow to normalize the homeostasis of a macroorganism, are highly relevant today. In relation to that the use of carotene synthesizing strains of bacteria of Bacillus genus is very perspective. This would allow connecting in one preparation the properties of probiotics and ability to compensate the deficiency of vitamin А in a macroorganism. The article presents the analysis of literature data along with the results of own research concerning carotene synthesizing activity of bacteria of Bacillus genus, the nature of their carotenoid pigments and their function in a macroorganism. It was determined that carotenoid pigments of B. amyloliquefaciens ІМВ В-7513 and ІМВ В-7525 strains were presented by a complex with lipids and carbohydrates, and belonged to C30-apocarotenoids, including apo-8'-phytofluene, apo-8'-ζ-carotene, apo-8'-neurosporene and apo-8'-β-carotene-3-ol. A possible way of carotene synthesis was proposed. The end product of its pathway synthesis probably is apo-8'-β-carotene-3-ol, which is able to be metabolized into vitamin A. Earlier it was shown that the investigated strains of bacteria are safe for warmblooded animals and exhibit probiotic and provitamin activity in vivo. The obtained results provide a fundamental basis for creation of a probiotic preparation with provitamin activity based on carotene producing strains B. amyloliquefaciens IMV B-7513 and B-7525.

It is shown that Bacillus subtilis IMB B-7516 and B. licheniformis IMB B-7515 strains are capable to decomposing crop residues. The effectiveness of the wheat straw decomposition by both strains was 15 - 30 %, sunflower and corn stubble - 40 - 60 % under the laboratory conditions. It is shown the role of pectinase and xylanase activity of the studied strains in the processes of destruction of plant residues. Ammonium nitrate is the best source of nitrogen nutrition for the manifestation of hydrolytic activity by strains Bacillus subtilis IMB B-7516 and Bacillus licheniformis IMB B-7515.

Such extreme factors as UV radiation, high temperature and salinity, and also the small amount of accessible water have an influence on microorganisms of coastal ecosystems of the Dead Sea. Resistance to these factors of the microorganisms isolated from ecosystems of this region (vertical steep gorge around the Dead Sea, clay-salt plain and black highly mineralized muds) is studied. Aerobic, chemoorganotrophic, thermotolerant, moderately halophilic bacteria which, according to their morphological and physiological properties, are similar to species Gracilibacillus halotolerans, Salimicrobium album and genus Caryophanon have been isolated from these ecosystems. All strains grew at 0-10% of NaCl in the medium (one strain--at 15% of NaCl), in the range of 30-50 degrees C. Resistance to UV radiation has been revealed in all the investigated bacteria Lethal doses of UV (LD90 and LD99.99) for spore-forming strains of genus Gracilibacillus were 100-170 and 1100-1500 J/m2, respectively; for strain Salimicrobium 6t1 (does not form spores)--70 and 400 J/m2; for the strain lt4 (genus Caryophanon), forming filamentous (or trychomes)--150 and 1400 J/m2. Some strains of genus Gracilibacillus had strong antagonistic effect on conditionally pathogenic test cultures Staphylococcus aureus 209p and Candida albicans UCM Y-690. It is conceivable that resistance of microorganisms of coastal ecosystems of the Dead Sea to extreme factors was generated under the influence of abiotic (physical and chemical) factors typical of this region.

Adhesion properties of probiotic strains Bacillus subtilis UKM 5139 and Bacillus subtilis UKM 5140 is studied. It is shown that the strain Bacillus subtilis UKM 5139 is nonadhesive, and the strain Bacillus subtilis UKM 5140 is subadhesive. Lactitol and lactulosa did not influence the adhesive properties of probiotic strains of bacilli, and reduced these properties of conditionally pathogenic microorganisms.

The influence of lactite and lactulose on growth of probiotic strains B. subtilis UKM 5139 and B. subtilis UKM 5140 and conditionally pathogenic microorganisms has been studied. It is shown that the extent of influence of these substances depends on their concentration. Addition of lactite or lactulose in the nutrient medium stimulated growth of probiotic bacilli strains in concentration of 15-20 % and inhibited growth of conditionally pathogenic microorganisms. It specifies the prebiotic properties of the studied disaccharides. It is established that the extent of inhibition of P. vulgaris, S. flexnery, S. enterica abony, E. coli 028 by lactulose was higher in comparison with the extent of their inhibition by lactite, but in turn lactite was more effective in relation to the strains E coli ATCC 25922, C. albicans, S. derby and S. aureus.

Growth peculiarities of probiotic strains B. subtilis UKM 5139 and B. subtilis UKM 5140 have been studied at their joint cultivation in deep conditions. It has been shown that in such conditions of cultivation the growth of bacilli and the accumulation of biomass of the cells that possessed high antagonist properties have been intensified. The mixed culture grown when the medium was inoculated by the strains B. subtilis UKM 5139 and B. subtilis UKM 5140 with the ratio of 1:2 was distinguished by the highest specific growth rate. Applicability of synthetic and complex media both for separate and joint cultivation of bacilli has been shown.

The effect of pH value of cultivation medium on biosynthesis by bacteria of Bacillus genus of different types of hydrolases has been studied. The optimum pH medium values for each of the studied enzymes were chosen that allowed to increase the activity of produced xylanases and lypases--1.3-1.5 times, endoglucanases--4-5 times, cellobiases--18-20 times and pectinases more than 2 times.