<p>An important link in solving the problem of healthy food is the intensification of the livestock, poultry and fish farming, which is possible only in the adoption and rigorous implementation of the concept of rational feeding of animals. In the implementation of this concept required is the application of probiotic preparations. Currently, there is an increased interest in spore probiotics. In many ways, this can be explained by the fact that they use no vegetative forms of the bacilli and their spores. This property provides spore probiotics a number of advantages: they are not whimsical, easily could be selected, cultivated, and dried. Moreover, they are resistant to various factors and could remain viable during a long period. One of the most famous spore microorganisms, which are widely used in agriculture, is <em>Bacillus subtilis</em>. Among the requirements imposed to probiotic microorganisms is mandatory – antagonistic activity to pathogenic and conditional-pathogenic microflora. The article presents the results of the analysis of antagonistic activity of collection strains of <em>B. subtilis</em>, and strains isolated from commercial preparations. We studied the antagonistic activity on agar and liquid nutrient medias to trigger different antagonism mechanisms of <em>B. subtilis</em>. On agar media, we applied three diffusion methods: perpendicular bands, agar blocks, agar wells. We also applied the method of co-incubating the test culture (<em>Escherichia coli</em>) and the antagonist (or its supernatant) in the nutrient broth. Our results demonstrated that all our explored strains of <em>B. subtilis</em> have antimicrobial activity against a wild strain of <em>E. coli</em>, but to varying degrees. We identified strains of <em>B. subtilis</em> with the highest antagonistic effect that can be recommended for inclusion in microbial preparations for agriculture.</p><p><em><br /></em><em></em></p>
<p><em>Bacillus subtilis</em> is the most studied bacterium from genus <em>Bacillus</em> and this microorganism is widespread in nature. <em>B. subtilis</em> is often found in fresh and seawater, in the rhizosphere, in the soil (especially contaminated with feces and manure). The large variety of strains are available in collections of microorganisms, but strains isolated from the rhizosphere of various plants are particularly interesting for science and practical use. At the same time, the morphological criterion (the form and other features of the colonies) is the main one in the identification of <em>B. subtilis</em> at the first stages of the study and allows to refuse of extraneous strains before use more expensive methods and materials. The article presents the description of the morphological diversity of <em>B. subtilis</em> strains that are used in agriculture. Typical R–colonies are characteristic of bacteria <em>B. subtilis</em>, and we established 2 morphologically diverse forms of these colonies in the studied strains.</p><p> </p>
Bifidobacteria commonly known as classic probiotics and today they gain huge popularity among supporters of wealth nutrition. These microorganisms colonize the intestines of a newborn baby through the mother's milk and joining him in a stable symbiosis, accompany the person throughout his life, exerting a beneficial effect on his health. These amazing microorganisms have great biotechnological potential and are widely used in medicine, veterinary medicine, food and pharmaceutical industries, agriculture and other fields of national economy. The beneficial effects of bifidobacteria on the host organism are vast and diverse. They are involved in enzymatic processes, perform vital minerals function (synthesis of vitamins B, K, folic and nicotinic acids), improve indices of protein, lipid, and mineral metabolism/ They also reinforce the hydrolysis of proteins, carbohydrates ferment, hydrolyzed fats, dissolve fiber, stimulate peristalsis, promote normal evacuation of the intestinal contents, promote the synthesis of essential aminoacids, better assimilation of calcium salts and vitamin D. Moreover, they have anti-anemic, anti-allergic action, and stimulate the lymphoid apparatus. The article presents a review of important technological and biological properties of bifidobacteria, which determine their biotechnological potential: culture-morphological, physiological, biochemical properties; habitat, taxonomy, nutrient medium, and conditions of incubation, antagonistic, antioxidant properties, acid resistance, probiotic properties, the practical application of bifidobacteria.
Представлены сравнительные данные антагонистической активности коллекционных штаммов L. acidophilus по отношению к тест-штаммам E. coli в зависимости от активной кислотности среды. К лючевые слова: антагонизм, Lactobacillus acidophilus, Echerichia coli, активная кислотность среды. The article presents the comparative data illustrating antagonistic activity of collection of strains of L. acidophilus in relation to the test strains of the E. coli depending on the active medium acidity.
The data on the study of the effectiveness of a new probiotic based on strains B. toyonensis B-13249 and B. pumilus B-13250 when growing shrimps are presented. The experiments were carried out on a private farm in Kazakhstan. The control group of shrimps, which did not receive the probiotic, completed the molting process on the 28th day of the experiment, and the experimental group – 10 days earlier. It was also found that the probiotic has a positive effect on the hydrochemistry of water in recirculating aquaculture system (RAS). The concentration of ammonium (NH3/NH4 +), nitrite (NO2) and nitrate (NO3-) nitrogen in the experimental group did not reach the limit value, in contrast to the control. Based on the obtained results, this probiotic can be recommended for greening aquaculture. The dosage of the probiotic when applied with brine shrimp as feed for shrimp is 1 g/100 g of dry cysts. The dosage of the probiotic when the RAS is added to the water is 5 g/600 l of circulating water once a week.
The ability of bacteria to quickly acquire antibiotic resistance and transfer it among different groups are created a global problem, since antibiotics are used not only in medicine, but also in agriculture. That is why to study of the antibiotic sensitivity of not only pathogenic bacteria, but also of beneficial microbes like Bacillus spp. is extremely important. Our results demonstrated that all the studied strains of the B. subtilis group were highly sensitive to cephalexin and enrofloxacin, while resistant to oxacillin. The B. subtilis B-5449 strain was the least resistant to the studied antibiotics, and the B. subtilis B-2896 strain was the most resistant.
Microbial biopreparations are actively used to prevent, diagnose, and treat infectious, allergic, tumor, and autoimmune diseases in humans and animals; to stimulate the growth and development of plant crops. Natural bacterial strains with valuable technical properties are a vital biological resource for developing new biopreparations and rotating already known microbial preparations in the world market. This study describes a new natural strain B. pumilus 16, which was isolated from the rhizosphere of Cichorium. The strain was identified using morphological and physiological parameters, biochemical tests, and primers Pum-f. and Pum-r. Antibiotic sensitivity and antagonistic activity against Escherichia coli were determined by diffusion of discs and delayed antagonism methods, respectively. The new natural strain (like type strains) fermented arabinose, cellobiose, mannitol, mannose, salicin, sucrose, and trehalose, and gave a positive reaction to arginine dihydrolase, ONPG, Voges-Proskauer test. It also gave a negative reaction to inositol, raffinose, sorbitol, methyl-D-glucoside, inulin, and lecithinase. B. pumilus 16, unlike the test strains, was capable of fermenting citrate. Strain B. pumilus 16 was highly sensitive to cephalexin (37.9±0.7 mm) and enrofloxacin (25.7±8.9 mm); sensitive to ole-andomycin (17.1±1.9 mm), benzylpenicillin (18.5±1.2 mm), and monomycin (16.0±0.6 mm); resist-ant to oxacillin. By the agar blocks method (7.3±1.5 mm), a more pronounced antagonism of the new strain against E. coli was recorded than by the method of agar wells (5.3±0.6 mm). Due to the level of antagonistic activity, B. pumilus 16 was more effective than the type strains (two of which did not show an antagonistic effect). On the basis of this, the new strain can be recommended for inclusion in the bacterial preparation composition for the national economy.
Data of the microbial biopreparation development for protection and crop growth stimulation on the Bacillus bacteria basis are presented. Three B. pumilus strains isolated from the Altai region (the Russian Federation) plants rhizosphere were selected as active components of the bacterial preparation. L-bulone was chosen as the nutrient medium for flasks cultivation of the inoculum. A molasses-based nutrient medium was used to incubate the bacilli in a 15-liter fermenter. The finished microbial preparation was obtained in dry form. The biopreparation is a powder consisting of a lyophilically dried concentrates mixture of genus Bacillus spores. Bacilli biomass were pre-mixed with a protective medium based on gelatin and sucrose. The final number of bacteria in the microbial preparation is 1.29(±0.30) ×1012 CFU/g.
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