A b s t r a c tThe general requirement for biologicals is that they must be insensitive to climate change and soil conditions, including soil physicochemical composition, fertility levels, and pH values. Actinomycetes isolated from extreme habitats are able to produce biologically active substances not only under neutral conditions but also in saline, alkaline and acidic environments, which determines their importance in the biopreparations, being developed for plant protection. This study is the first to report the Streptomyces sp. strain K-541 antibiosis against the causative agents of several cereal fungal infections under various environmental conditions and the identification of the antibiotic produced. Streptomyces sp. strain K-541 isolated from extreme ecosystems of Kazakhstan was cultured under neutral (pH 7.0) and alternative growth conditions at 25.0 g/l NaCl (pH 7.2) or 2.5 g/l Na 2 CO 3 (pH 8.0). Antifungal activity was determined in agar block diffusion experiments and under paired coincubation with phytopathogenic fungi Fusarium solani (Mart.) Sacc., F. oxysporum Schlecht., F. heterosporum Nees, F. sporotrichiella Sherb., Piricularia oryzae Cavara, Alternaria triticina Prasada & Prabhu, A. alternate (Fr.) Keissl., Bipolaris sorokiniana (Sacc.) Shoemaker, and Aspergillus niger van Tieghem. For antibiotic A-541 production, the strain was cultured on an orbital shaker (180-200 rpm) for 120 hours at 28 С. The antibiotic was extracted with organic solvents and analyzed using thin layer chromatography and spectrophotometry. The studies have shown high antifungal activity of K-541 against all the phytopathogens examined. After 72 hour incubation at 25 С the growth inhibition zones were 20-56 mm in diameter depending on growth conditions which simulated different ecological niches. In co-culturing the strain K-541 and the phytopathogenic fungi, the fungal colonies decreased 1.8-2.7 times in diameter indicating the possibility of K-541 introduction into soil biocenoses for biocontrol of cereal fungal pathogens. High inhibition of growth was also observed under saline (2 % NaCl) and alkaline (0.2 % Na 2 CO 3 ) conditions. The antibiotic produced by strain K-541 was classified as a member of polyene group, a subgroup of the hexaenes. So strain K-541 is recognized as promising for the development of a new biopreparation with fungicidal activity against causal agents of cereal fungal infections under different environmental conditions.

В обзоре проанализированацелесообразность применения пробиотиков и пребиотиков. Последние годы во всем мире наблюдается повышенный интерес к пробиотикам и пребиотикам и их использованию для сохранения и поддержания здоровья, а также лечения ряда заболеваний. Исследования пробиотиков дают основания предполагать наличия у них множество положительных свойств. Наиболее часто в качестве пробиотиков используются штаммы лакто- и бифидобактерий, которые являются достаточно безопасными даже для питания детей грудного и раннего возраста. Представлены пути, посредством которых пробиотики реализуют лечебный эффект. Показано, что они эффективны при многих заболеваниях, включая острые кишечные инфекции и другие воспалительные болезни кишечника, течение аллергического процесса, расстройства иммунитета. Нормальная микрофлора человека, нормофлора, выполняет ряд важных функций в поддержании жизнедеятельности организма. Защитная функция осуществляется в первую очередь бифидо – и лактобактериями, благодаря их способности подавлять патогенные бактерии и конкурировать с ними. Одним из важнейших функций микроорганизмов нормофлоры организма человека является иммуногенная стимуляция иммунной системы. Наиболее убедительные доказательства эффективности пробиотиков связанны именно с их использованием для улучшения функционирования кишечника и влияния на иммунную систему. The review analyzes the feasibility of using probiotics and prebiotics. In recent years, there has been an increased interest in probiotics and prebiotics and their use for the preservation and maintenance of health, as well as the treatment of a number of diseases around the world. Studies of probiotics suggest that they have many positive properties. Most often, strains of lacto- and bifidobacteria are used as probiotics, which are safe enough even for feeding infants and young children. The ways by which probiotics implement the therapeutic effect are presented. It has been shown that they are effective in many diseases, including acute intestinal infections and other inflammatory bowel diseases, the course of the allergic process, and immune disorders. Normal human microflora, normoflora performs a number of important functions in maintaining the vital activity of the body. The protective function is carried out primarily by bifidobacteria and lactobacilli, due to their ability to suppress pathogenic bacteria and compete with them. One of the most important functions of microorganisms of the normoflora of the human body is immunogenic stimulation of the immune system. The most convincing evidence of the effectiveness of probiotics is associated with their use to improve the functioning of the intestine and influence the immune system.