Характеристика біологічних властивостей лактобацил за аеробних та мікроаерофільних умов атмосфери інкубації

Abstract

У роботі наведено дані щодо вивчення газового складу атмосфери культивування на ростові та антагоністичні властивості лактобацил, вилучених з різних еконіш. Встановлено, що динаміка росту та кількість спожитої лактобацилами глюкози у всіх досліджених штамів лактобацил за умов мікроаерації була вищою у порівнянні з аеробними умовами культивування. При вивченні антагоністичних властивостей лактобацил за аеробних та мікроаерофільних умов культивування встановлено, що за мікроаерофільних умов культивування відбувалось достовірне (р<0,05) зменшення питомої ваги нечутливих та збільшення частки високочутливих штамів стафілококів у порівнянні з аеробними умовами культивування.

В работе приведены данные по изучению газового состава атмосферы культивирования на ростовые и антагонистические свойства лактобацилл, выделенных из разных экониш. Установлено, что динамика роста и количество потребленной лактобациллами глюкозы (у всех исследованных штаммов) в условиях микроаэрации была выше по сравнению с аэробными условиями культивирования. При изучении антагонистических свойств лактобацилл в аэробных и микроаэрофильных условиях культивирования установлено, что при микроаэрофильных условиях культивирования происходило достоверное (р<0,05) уменьшение удельного веса нечувствительных и увеличение доли высокочувствительных (по отношению к биологически активным веществам лактобацилл) штаммов стафилококков по сравнению с аэробными условиями культивирования.

To correct the dysbiotic conditions of the urogenital and gastric tracts, probiotics are most often used, which include lactobacilli. As for the use of probiotics based on lactobacilli to restore normal flora of the upper respiratory tract, we did not find such information in the literature available to us, although lactobacilli are among the obligate representatives of the human micro flora and are, to a greater or lesser extent, present in all open cavities of the body. This allows to search and select candidates for production strains among representatives of alternative econiches. The conditions in the biological niches of the human body can differ significantly from those created in vitro by many parameters, including the gas composition of the incubation atmosphere. That is why we set the following goal: to conduct a study of the biological properties of promising strains of Lactobacillus spp. under conditions of different concentrations of oxygen in the atmosphere of their cultivation. The first stage of the study was to explore of metabolic activity and growth properties of lactobacilli. It is known that the level of metabolic processes is the initial indicator of the ability of microorganisms to actively develop. Metabolism requires a constant and continuous influx of energy, the universal source of which for most organisms is glucose. That is, determining the amount of recycled glucose and the rate of its utilization can serve as an indicator of the potential rate of development of subpopulations. Based on the foregoing, the level of enzymatic processes (the amount of glucose consumed by lactobacilli) was first studied, which is the initial indicator of the potential ability of cells to actively develop. In the course of the conducted researches it was established that the micro-aerophilic conditions contributed to an increase in the amount of glucose consumed by lactobacilli. Thus, under conditions of reduced partial pressure of oxygen, the amount of glucose consumed by lactobacilli increased, on average, in probiotic strains - by 1,2 times, and in the cells - by 1,3 times (p <0,05). The results obtained to stimulate the process of glucose consumption by lactobacilli, possibly associated with a change in the rate of metabolic processes in conditions of oxygen deficiency. The next stage was the study of the growth properties of lactobacilli under various conditions of the gas composition of the atmosphere of cultivation. Changes in growth properties were determined under aerobic conditions of cultivation and under conditions of reduced partial oxygen pressure in lactobacilli with a high level of glucose consumption: L. plantarum (isolated from bees), L. rhamnosus GG (isolated from a probiotic) and L. casei (isolated from humans). In the course of the studies, it was noted that the growth rates of the explored bacteria, although differing in some strains (strain L. plantarum, isolated from the intestines of bees, had more active growth properties), but had general trends of changes in growth properties. The exponential phase of growth, on average, was within 2-12 hours. The probiotic strain was less active than others. The growth dynamics of all strains of lactobacilli under microaeriation conditions was higher in comparison with aerobic cultivation conditions. However microaerophilic cultivation conditions did not affect the duration of the lag phase of all the studied strains of lactobacilli. The biggest differences in the indices, under different conditions of the gas composition of the incubation atmosphere, were noted for the exponential phase and the phase of steady growth of lactobacilli. In the probiotic strain, the indices differed by 1.2-1.4 times (p <0.05). The same tendency was noted for a strain isolated from humans. The difference between the growth indices, under different conditions of the gas composition of the cultivation atmosphere, differed 1.2-1.6 times (p <0.05) in this strain. The most active in the accumulation of biomass was a strain isolated from the intestines of bees. Under different aeration conditions, the difference between the indices of their growth was 1.2-1.8 times (p <0.05). The next stage of the research was the study of the competitive properties of these lactobacilli by the method of delayed antagonism on the “nasal” strains of S. aureus. Under microaerophilic culture conditions, there was a significant (p <0.05) decrease in the specific gravity of insensitive and an increase in the proportion of highly sensitive test strains of staphylococci compared to aerobic cultivation conditions. Thus, experimental results on the growth and antagonistic properties of lactobacillus test cultures under aerobic and microaerophilic conditions of the cultivation atmosphere provide an opportunity to study the microbial interaction in human tissues in the inflammatory processes of the upper respiratory tract and disclose the use of lactobacilli for the control of diseases of staphylococcal origin.