Total Microbial Number Research Articles

Quality and safety of dry protein and carbohydrate composite based on HACCP principles

Creating complete feed for cattle especially during the period of indoor housing is an important task of feed production. This determines the increase in milk yield and live weight, and the profitability of all production. Biotechnology of obtaining a combined feed additive in the form of a dry protein and carbohydrate composite for animals from plant raw materials and secondary raw materials allows us to solve this problem. At the same time, the quality and safety of the composite is an extremely relevant topic. In the course of research the influence of technological factors control, based on the principles of HACCP, on the quality and safety indicators of the combined feed additive has been established. The resulting product according to organoleptic indicators is a loose mixture of no more than 5–8 mm in size, without solid inclusions, foreign impurities and fumes; color is from gray to brown; smell is characteristic of the set of components included in the recipe, without musty, mold and other odors. Physical and chemical parameters are as follows: mass fraction of moisture no more than 14 %; mass fraction of sugars is at least 27–30 %; mass fraction of protein is 17,6–18,4 %, fiber content is 7,0–7,3 %. Safety indicators: total number of fungi (CFU/g) no more than 5×10[sup]4[/sup] ; total microbial number (CFU/g) no more than 5×10[sup]5[/sup] . The presence of Salmonella in 25 g is not allowed; the presence of pathogenic Escherichia in 1,0 g is not allowed. The remaining safety indicators, due to their invariability in the process of technological operations, must comply with the indicators provided for in the normative documents for raw materials. Five control critical points in the technology of proteincarbohydrate composite production that pose a threat to its quality and safety have been identified. It has been shown that the preliminary assessment and proposed corrective actions for managing hazards at all stages of the production process, which significantly affect the safety of products, can prevent the appearance of a danger of deviations from the parameters of the technological process at each stage of production.

The analysis of spatio-temporal features of microbiological and hydrochemical indicators of the rivers within Surgutsky and Oktyabrsky Districts in Khanty-Mansi Autonomous Okrug – Yugra

The study of the environmental situation in river basins, including the assessment of actual water pollution, has recently become relevant. Water bodies located within the borders of oil production territories are experiencing constant and intense anthropogenic impact, which occurs not only during the operation of fields, but also during the preparation of areas for exploration and production drilling, construction of multi-well pads, communications, etc. This paper analyzes peculiarities of microbiological and hydrochemical indicators distribution of the rivers within Surgutsky and Oktyabrsky Districts in Khanty-Mansi Autonomous Okrug Yugra. The cluster analysis method determines cascade systems based on the total microbial number of the studied rivers. The characteristics of the generic composition and distribution of the identified microorganisms are given. As a result of the cluster analysis, it was revealed that organoheterotrophic microflora is found mainly in the studied rivers. 16 bacterial cultures and 3 cultures from the mycelial microflora were identified among the isolated microorganisms. The paper also presents the results of rivers monitoring in 20182019 on the following water quality indicators: pH, ammonium ions and acute toxicity. The time variability of hydrochemical indicators correlates with different phases of the hydrological regime of rivers.

Betacyanin as Bioindicator Using Time-Temperature Integrator for Smart Packaging of Fresh Goat Milk.

Smart packaging is a packaging system with embedded sensor or indicator technology, which provides information on the quality of the product, especially perishable foods such as goat milk. One application of smart packaging is to use a time-temperature bioindicator. The purpose of this study was to determine the quality of fresh goat milk during storage at freezing temperatures (−20 ± 2°C) for 31 days and room temperature (25 ± 3°C) for 24 hours using a time-temperature indicator by utilizing a natural dye betacyanin. The method used was descriptive analysis, and the data obtained were processed using the correlation regression test. The samples were observed at freezing temperature every 24 hours and room temperature at 0, 1, 2, 3, 4, 5, 6, 8, 10, and 24 hours. The observation criteria consisted of changes in bioindicator color, milk pH, and total microbes. The results showed that color changes of the bioindicator film at room temperature were more noticeable than at freezing temperature. Based on changes in color of the bioindicator at room temperature, the sample was safe for consumption until the 5th hour with pH 6.51, and the biofilm color characteristics were L∗ = 82.49, a∗ = 21.46, and b∗ = −7.33, but the total number of microbes did not fulfil Indonesian National Standard at the 24th hour, i.e., 1.36 × 106 CFU/ml. At freezing temperatures, fresh goat milk was still safe for consumption until the 31st day with pH 6.51 and total microbe of 1.89 × 105 CFU/ml, and the biofilm color characteristics were L∗ = 80.52, a∗ = 24.15, and b∗ = −7.91. The results of this study concluded that the milk expiration limit based on the betacyanin indicator was 5 hours at room temperature and 31 days at freezing temperature.

Microbiological assessment of drinking water quality at different stages of water treatment

The object of research is the quality of sources of centralized water supply according to epidemiological indications and the technology of their disinfection at different stages of water treatment using the example of the «Zhytomyrvodokanal» utility company (UC) (Ukraine). The object of research is evaluated and it is found that studying the bacteriological state of water bodies that are sources of centralized water supply is currently one of the most important tasks. Especially, given the significant impact of human activities on surface waters and the insufficient pace of modernization of water treatment equipment. It is determined that widespread disinfection methods using ultraviolet and chemicals (chlorination and ozonation) have their strengths and weaknesses. The paper presents the results of analyzes of water from sources of centralized water supply at different stages of water treatment accordi"ng to microbiological indicators during 2019: total microbial number (TMN) and total number of coliphages. The unsatisfactory condition of water bodies has been established; it is a source of water supply in the city. It is proved that the existing technology of disinfecting water from centralized water sources, which is carried out in two stages using soluble chlorine and sodium hypochlorite, is effective in neutralizing bacteria of the Escherichia coli group. As a research result, the dependence of the concentration of microorganisms in water sources of centralized water supply on weather conditions is revealed (in total, microbial pollution is observed from May to October). A moderate level of water pollution (ranging from 1.1 to 7.5 units) has been proven by the epidemiological criterion in the «Denyshi» and «Vidsychne» reservoirs (Zhytomyr Region, Ukraine). It has been established that the epidemiological criterion is an acceptable level in clean water tanks. It can be argued that the water in the tanks is suitable for drinking water use by the local population. Thus, the research results show that the technology of water disinfection (involves the introduction of two stages of water treatment) used at the «Zhytomyrvodokanal» UC is effective. Accordingly, this technology may be interesting for other settlements, in the absence of significant funds for the modernization of equipment and in the face of climate change, accompanied by an annual increase in temperature and an increase in the number of microorganisms in water sources.

СРАВНИТЕЛЬНЫЙ АНАЛИЗ МИКРОБИОЛОГИЧЕСКИХ ПОКАЗАТЕЛЕЙ КАЧЕСТВА ПОВЕРХНОСТИ ПЛОДОВООВОЩНЫХ ПРОДУКТОВ, ОБРАБОТАННЫХ ВОДОЙ И ЭЛЕКТРОХИМИЧЕСКИ АКТИВИРОВАННЫМ ВОДНЫМ РАСТВОРОМ

The method of improving the microbiological safety of food products based on the use of an electrochemically activated solution of chlorine-oxygen and hydroperoxide compounds was researched. The issue of food products cleaning is very relevant in catering. It’s usually used tap water for cleaning of vegetables and fruits, not disinfectant solutions or physical processing methods. During the analysis of this problem, several experiments were conducted with the «Анолит АНК СУПЕР» (anolyte) as a disinfectant for food products. The active agents of this solution are represented by a mixture of highly active metastable chlorine-oxygen and hydroperoxide compounds. To study the action of the anolyte, a research was conducted to determine the total microbial number (QMAFAnM) and the presence of yeast and fungi on the surfaces of the selected raw materials. It was used microbiological rapid tests «Петритест». Samples were: fresh carrots, fresh celery (leaf), fresh apples. During the research of raw materials treated with water supplied by a centralized drinking water supply system, it was determined that its level of contamination is large. When the samples treated with a disinfectant solution, a positive effect was observed: no seeds were found on the test materials. Anolyte’s using did not affect the organoleptic Евразийский Союз Ученых (ЕСУ) # 3(72), 2020 5 indicators: freshly squeezed juice was made from the processed raw materials and tasted and smelled like the drink which was made from fruits and vegetables and treated by tap water. A comparative analysis of the results was carried out and it was found that the use of the test solution had a positive effect on the microbiological safety of raw materials

NON-TRADITIONAL RAW MATERIALS FOR BIOTECHNOLOGICAL PRODUCTIONS AND SOME ENVIRONMENTAL ASPECTS OF THEIR DISPOSAL

It has been proved in the work that non-traditional, annually renewable wastes of plant raw materials − cuttings of fruit trees, hop stems and castor bean stems − are rational to be used for further biotechnological processing in order to obtain a valuable protein feed supplement. The negative impact of burning these plant wastes on soil microbiota has been confirmed. Technological properties, chemical and biopolymer composition of the plant waste have been studied. It has been found out that the optimum particle sizes for all three types of the studied waste are 20–35 mm in fibre length. Such grinding degree provides the best diffusion of the hydrolyzing agent into the particles of the raw material and the extraction of monosaccharides into the solution. All types of the analysed plant waste have a high content of polysaccharides, extractive substances, which will allow to use them as potential raw materials for the development of nutrient media to cultivate microorganisms in biotechnological industries. Acid degradation of biopolymers of the analysed raw materials has been carried out in laboratory conditions. Hydrolysate-based nutrient media have been obtained in laboratory conditions and their biological quality has been studied. Yeast culture strains, which are able to grow actively on the hydrolysates of fruit tree cuttings, hop and castor bean stems, have been selected, and Candida tropicalis culture has been cultivated during the process of periodic cultivation. The negative impact of burning plant residues on the soil microbiological status has been investigated. Samples of the soil were taken from the experimental plot before and after burning of the plant waste, microbiological studies of the total number of mesophilic aerobic and facultative anaerobic microorganisms, and nitrogen-fixing ones were conducted, since they are the only living organisms capable of absorbing molecular nitrogen from the air and incorporating it into the cycle of nitrogenous substances. The total number of microbes is reduced by 45%, and the number of nitrogen-fixing bacteria is halved. The process of their regeneration is rather slow, which will significantly affect soil fertility, and soil ashing can lead to changes in crops capable of producing high yields on this soil, and will require scientifically based crop rotations.

The impact of pesticides on the electrogenic activity of the sludge in microbial fuel cells

The influence of Gezagard herbicide (active ingredient – promethrin, 500 g/l) and fungicide Kolosal (active principle – tebuconazole 250 g/l) on the dynamics of electrical indicators of microbial fuel cells (MFC) with activated sludge treatment plants as a bioagent was studied. It was shown that the tested pollutants reduced the electrogenic activity of sludge in MFC when the content in wastewater was from 0.1 g/l. The studied toxicants in the indicated concentrations significantly inhibited the dehydrogenase activity of the sludge microorganisms and the total microbial number. At the same time, the Kolosal fungicide had a more pronounced negative effect on all the studied parameters than the Gezagard herbicide. There is a positive relationship between the results of evaluating the electrogenic activity of sludge and such classical methods of its analysis as dehydrogenase activity and the total microbial number. This suggests that the ability of the sludge to generate an electric current in MFC can be used as one of the parameters for assessing its physiological state. In addition, in the case of a mono-composition of pollutants, MFC with activated sludge can be used as a tool for the initial non-specific assessment of wastewater pollution by pesticides.

Substantiation and optimization of quantity and type of mechanical cleaners supplied to milk pipe when rinsing milking units

The article presents the results of production tests of three designs of mechanical cleaners intended to increase the efficiency of sanitary processing of milking installations. As a result of the experiment, the optimal number of mechanical cleaners and their type were determined. The optimization criterion was the total microbial number (KMAFAnM) obtained as a result of seeding on the nutrient medium of washings from the inner surface of the milk line. As a result of the experiment, it was determined that the optimal result is achieved by sanitizing a milking unit with 4-5 mechanical cleaners with a cleaning surface of bristles.

Анализ геохимического, микробиологического состояния и флористического состава родников Актюбинской, Западно-Казахстанской и Атырауской областей

Приведены результаты гидрохимического и токсикологического обследования16 родников Актюбинской, 12 родников Западно-Казахстанской и трех родниковАтырауской областей Западного Казахстана. Дана характеристика содержания вгидрогеохимических пробах родниковой воды катионов и анионов, тяжелых металлов,показатели микробиологического исследования воды (общее микробное число, общиеколиформные бактерии, термотолерантные колиформные бактерии), факторы бактериальнойконтаминации родников в сопоставлении с санитарными нормами и требованиям к качествуводы.Представлены результаты флористических исследований родников, перечень редких иохраняемых видов флоры родниковых комплексов, занесенных в Красную Книгу России иКазахстана

ПРИМЕНЕНИЕ МЕТОДА АТФ-БИОЛЮМИНЕСЦЕНЦИИ ДЛЯ ОЦЕНКИ КАЧЕСТВА САНАЦИИ ДОИЛЬНОГО ОБОРУДОВАНИЯ

The article presents the results of determining the relationship between the total microbial number and microbial ATP on the surface of milking equipment before and after treatment with neutral anolyte ANK-SUPER. The possibility of using the ATP-bioluminescence method to control the quality of sanitation of milking equipment on dairy farms is shown. Laboratory studies revealed a proportional relationship between the level of bacterial ATP and the number of bacteria on the surface of milking equipment before and after sanitation.

Assessment of indoor environment to influence the production of gosling broilers when using sanitary litter

The purpose of research and production experiment in the conditions of Akhmetov farm located in the Vysokogorsky district of the Republic of Tatarstan was to study a new sanitary litter material and the effect on the indoor environment, production, viability and feed input required to rear gosling broilers. The experiment found that the new sanitary litter material, made of thermochemically and biotechnologically processed woodworking waste, over the entire period of research was characterized by higher qualities compared to raw sawdust. Accordingly, in the end, the moisture of the said material was lower by 28.5 %, the total microbial count and numbers of microscopic fungi were less by 13.3 % and 19.9 %, respectively. The said litter material helped to improve the environment in the poultry house, which reduced harmful gases (carbon dioxide – 0.11 % and ammonia – 0.33 mg/m3), dust – 0.9 mg/m3 and microorganisms – 8.9 thousand bwt/m3. Ultimately, this contributed to a higher daily live weight gain by 7.51 % and livestock viability by 1.80 %, and, sequentially reduced feed input per 1 kg of live weight gain by 4.98 %, as compared with the control.

Possibility of using Bacillus and Trichoderma strains for decomposition of crop residues

The objective of this study was to investigate the possibility of using microbial strains as residue decomposers and to determine the effect of these strains on chemical and microbial properties in the residue-amended soil. Greenhouse experiment consisted of eight Bacillus treatments, three Trichoderma treatments, and their combination, all applied to non-sterile chernozem soil amended with wheat straw. Incorporation of wheat straw improved soil chemical and microbial properties, while the extent of residue decom?position under microbial strains was intensified. Microbial treatments significantly affected the soil pH, the content of carbonate, total carbon, soil organic carbon, humus, and available phosphorus and potassium. Bacterial and fungal treatments also significantly influenced the total microbial number, ammonifiers, N2-fixers, fungi, actinomycetes, oligotrophs, copiotrophs, and cellulolytic microorganisms. The effect of microbial treatments varied depending on the applied strains and examined properties, with Bacillus strains being more promising residue decomposers compared to Trichoderma strains. The most effective microbial strains could be used as potential decomposers of crop residues.

Detection of Viable but Nonculturable Microbial Cells in Chicken Mince

The relevance of the study and the presence of gaps in the relevant knowledge on the topic. Potential existence of hazardous viable but nonculturable (VBNC) cells of pathogenic microorganisms in foodstuffs that can be formed under the influence of various factors, their detection and determination of conditions for formation of VBNC cells of various contaminant bacteria are relevant for preventing contamination of meats.Methods. In the study, a search was conducted for VBNC cells in chicken mince in real time and during experimental infection of it by Staphylococcus aureus 209P. In order to detect VBNC cells in chicken mince, total number of microbes, number of bacterial colonies (CFU), and the portion of living (dead) cells were determined in 1g of the product using a commercial set of fluorescent dyes. A second study was carried out after 5 h of incubation of tested samples at room temperature.Results and discussion. In samples of minced meat on the 4th day after production, more than 99% of all detected living cells were VBNC. After 5-hour incubation of the sample, the number of CFU/g increased by 22.5 times, but the portion of VBNC cells remained higher than 99% of viable bacteria. During artificial infection of the same batch of mince with S. aureus in broth culture at the stage of logarithmic growth, the amount of VBNC cells for 0 hours was 97.3%. After 5 hours their number increased to 99.99%. Probably, in the introduced culture of Staphylococcus at the stage of active reproduction, formation of VBNC bacteria did not occur, which initially reduced their number in the sample. After 5-h incubation, transition of bacteria to VBNC state was accelerated, possibly due to unfavorable conditions for the cell population (changes in trophic substrate, temperature, pH, etc.).Conclusions. Experimental data confirm presence of VBNC bacteria in chicken products that don’t grow on traditional nutrient media, and showing a false negative result in traditional microbiological expertise. Because of the biohazard of such dormant cells, it is advisable to provide regulated testing of foodstuffs for presence of VBNC cells.

Efficiency of application of modern sanitation supplies in beekeeping

The article presents the results of studies of the effect of commercial disinfectants registered in Ukraine and allowed for use in beekeeping, as well as a comparative characteristic of their effectiveness in the disinfection of wooden beehive structures. The research was conducted on the basis of the departments of hygiene, sanitation and general veterinary prevention and technology of production and processing of products of small animals of the Lviv National University of Veterinary Medicine and Biotechnology named after S.Z. Gzhytskyi and SLW “Biolab” Food and Veterinary Diagnostic Laboratory (Ostroda, Poland). For research in the spring and summer period 4 groups of test objects were formed on the principle of analogues. Distilled water was used to control disinfection (test group 1). In the second experimental group for disinfection used “Brovadez-20” (active substance benzalkonium chloride 0.5%), in the third experimental group гру “Vetox-1000” (active substance hypochlorite 0.3%) and in the fourth experimental group – “Sumerian silver”(active ingredient of 10% citrate of Argentum citrate). In a comparative analysis of the effectiveness of the disinfectants of the II, III and IV groups, the growth of gram-positive (Streptomyces badius, Curtobakterium) and gram-negative bacteria (Xanthomonas hyacinthi, Pseudomonas alcaligenes, Acidovorax defluvii) was detected, respectively, among the endophores. In the current literature, information on the threat to the health of the honey bee detected by microorganisms is missing. According to the research, certain differences between the effectiveness of disinfectants have been established. It was found that the total microbial number (BMI) was 0.15% in group II, 0.16% in group III and up to 0.10% in group IV relative to control. It was found that the Sumer silver disinfectant at 10% concentration provides the best bactericidal effect (P < 0.001). In a comparative intergroup analysis of the effectiveness of disinfectants, it was found that in the conditions of the experiment, the level of bactericidal activity was the highest in the experiment with the SMC in the case of the use of “Sumer silver” was 32.3% and 34.4% better compared to “Brovades-20” and “Vetox-1000”, respectively. The use of “Sumerian silver” allows you to get the desired result 10 and 4 times faster than the disinfectants “Brovadez-20” and “Vetox-1000” respectively.

Effect of liquid smoke on microbiological and physico-chemical properties of beef meatballs during storage

Meatballs beef is a processed-meat product which has distinctive texture characteristic and is classified as perishable food products. Microbiological and physico-chemical properties are essential factors in determining the quality of meat products, and one of the things affecting the quality is the interaction between smoke and food components. The objective of this study was to evaluate the effect of liquid smoke on the microbiological and physico -chemical properties of beef meatballs during storage. The research method used explanatory research with five treatments and three replications and analyzed with a regression model. Beef meatballs without the addition of liquid smoke were used as controls, while the addition of liquid smoke 1.0 %, 1.5%, 2.5%, 2.5%, and 3.0% were used as treatments. The parameters analyzed consisted of pH, total microbial number, color, and texture profile of beef meatballs. The storage time significantly has a negative effect on the pH value but has a positive effect on the total microbial number and texture parameters (hardness, springiness, cohesiveness, and gumminess). Increased liquid smoke concentrations in beef meatballs can significantly reduce microbe damage, maintain texture during storage, and increase the total color difference. Liquid smoke can be used as a natural preservative alternative, which is safe for beef meatballs. However, it must be considered about consumers' preference for the smoky aroma and flavor obtained.

ON INTEGRATION OF WASTEWATER TREATMENT TECHNOLOGIES AND PRODUCTION OF RENEWABLE ENERGY SOURCES

The work is devoted to the study of technological processes corresponding to the requirements of the developing closed-loop economy, which will be based on the wide use of renewable resources, maximum recycling of secondary raw materials, with the transition from fossil fuels to renewable energy sources as one of the objectives. A study of the possibility of producing fatty acid esters from renewable raw materials of plant origin - microalgae Chlorella vulgaris - with the use of municipal wastewater was carried out. Approaches to the development of technologies of fatty acid esters production and promising ways to improve the key stages of such production are considered. It is shown that under certain conditions (temperature of 10-32 °С, illumination of 7-14 klx) municipal wastewater can be treated and at the same time serve as a nutrient medium in the process of cultivation of microalgae biomass with lipid content of 10-18% of dry matter. Depending on the conditions of cultivation, the cells of the Chlorella vulgaris IPPAS C-2 strain of microalgae reduce the concentration of ammonium cations, phosphate anions and total microbial number in municipal wastewater by 93 - 95% (wt.), 90 - 97% (wt.) and 86 - 95%, respectively. The influence of technological conditions of the process on the biomass growth rate and fatty acid composition of accumulated lipids is analyzed. It is experimentally established that triglycerides, O-dialkylmonoglycerides and fatty acids have the greatest inhibiting effect on the microflora of wastewater. Using Hansen solubility parameters, a system of polar and non-polar solvents consisting of ethanol and petroleum ether in the ratio of 1:2 (vol). was selected, which ensures the efficient conduct of the extraction process. The yield of fatty acid esters of КFAE = 45% was obtained in the course of transesterification reaction with the use of ethanol in the ratio with lipids 6:1 (mole) at the reaction temperature of 60 °C in the presence of an alkaline catalyst - sodium hydroxide (3% of the mass of lipids).

Analysis of environmental safety of recreational territories of mountain ecosystems and development of technical measures for its stabilization

We studied ways of ensuring of the environmental safety of recreational territories of a mountain ecosystem on the example of Vizhnytsky National Nature Park (NNP) in the Pokutsko-Bukovynian Carpathians. Existing approaches to ensuring of the environmental security of nature reserve objects have been analyzed. The characteristic of the study region has been given. We proposed the concept for ensuring of the environmental safety of recreational areas. Its base is analysis of components and identification of components, improvement of which would ensure the appropriate level of environmental safety of NPP. An algorithm has been constructed for theoretical and experimental studies for assessment of the sanitary-microbiological state of the atmosphere, hydrosphere and soils in the study area and their influence on the environmental safety of NPP. We monitored sanitary-microbiological and sanitary-environmental indicators of the hydrosphere, atmosphere and soil and identified environmental threats to analyze the state of recreational territories of the mountain ecosystem. It is proposed to plan measures for intensification of biological natural processes of self-purification of surface water in the area of recreation territories to ensure preservation of the limited values of sanitary-microbiological and sanitary-environmental indicators of the hydrosphere. The results of atmospheric air monitoring in the area of the recreation territories indicated that the air ion content was 2.4 times higher, and the total microbial number was 1.5 times lower than in the territory of traditional farming. Therefore, the atmosphere of the recreation area does not require any technical measures to improve it. A system of engineering measures has been proposed for stabilization of environmental safety in the area of recreational territories (using the Viya fibrous carrier) for intensification of purification of surface water and disposal of wood waste by biofuel production. Implementation of the proposed measures would help achieve stabilization of the environmental safety of the recreational territories of the mountain ecosystem

DISTRIBUTION AND VARIABILITY OF THE HETEROTROPHIC, COLIMORPHIC AND LACTIC ACID BACTERIA NUMBER IN WATER AND AQUATIC ORGANISMS OF THE BLACK SEA

Currently, there is an active revision of established positions in classical microbiology, both in the area of sanitary-microbiological indicators of water quality and the search for groups of microorganisms that were previously thought to be not to be present in seawater and the microbiota associated with its inhabitants. The results of the study of the numbers of the main groups of microorganisms that make up proxy indices for sanitary-microbiological indicators and the numbers of lactic acid bacteria were shown in this article.The aim of this study was to compare the total microbial number, lactic acid bacteria and colimorphic bacteria in sea water in microbiota associated with its inhabitants depending on the season. Materials and methods. To study the abundance index of various groups of microorganisms, classical microbiological methods were used. To calculate the presence of a relationship between signs, we used the «corrplot» package in program R 3.4.0.Research results. The presence of lactic acid bacteria in the water of the Black Sea and among the associated microbiota of aquatic organisms has been shown for the first time. It was shown that the maximum abundance of this group in water (1.5 ± 0.33×104 CFU/ml) was recorded in July, and the maximum abundance among the associated microbiota (1.66 ± 0.61×104CFU/ml) was recorded in October. The distribution of the number of colimorphic bacteria and bacteria that grew on bismuth-sulfide agar in the study of seawater was the opposite, and in the study of the associated microbiota was the same. The maximum of the total microbial contamination in water was recorded in October (1.1 ± 0.7×106 CFU/ml) in the associated microbiota of aquatic organisms in July. Correlation relationships between the number of bacteria characterizing the total microbial contamination, colimorphic bacteria and lactic acid microorganisms was revealed. Seasonal changes in the number of the studied groups of microorganisms were shown.Conclusions. Various principles of the distribution of heterotrophic, colimorphic and lactic acid microorganisms depending on the season and place of excretion have been identified.

Application of x-ray fluorescence spectrometry in assesment of ultrafiltration membrane surface condition at water pre- treatment units of thermal power plants

The objects of the study were the Doy Chemical hollow-fiber ultrafiltration membranes which were use for preparation of make-up water for the Novocherkasskaya Regional Thermal Power Plant (RTPP).We tried out a possibility of applying the X-ray fluorescence spectrometry to study the condition of the spent non-recoverable ultrafiltration membranes in order to identify the causes of their irreversible destruction. The ARL Quant’X X-ray fluorescence energy dispersive spectrometer of Thermo Scientific (USA) was used in the study.Thin cuts of the Doy Chemical hollow-fiber ultrafiltration membranes were used in the experiments, which had worked for more than three years in the field conditions of the feed water of the Don River, Russia.The analysis of the obtained samples spectra allowed us to assume that the membranes were irreversibly contaminated by iron bacteria. Basing on the conclusions made during the analysis of X-ray fluorescence spectra we developed and tested in field conditions one of the optimization variants for technological pretreatment scheme. This scheme enables a significant increase in the service life of ultrafiltration membranes, even when the feed water is heavily contaminated by bacteria. Field tests of the modernized technology were carried out at Novocherkasskaya RTPP during 2016-2018 and showed a significant increase in the service life of the membrane modules. At the same time, the quality of the filtrate, productivity and pressure drops at the cascades of ultrafiltration units fully corresponded to the normative values even in conditions of deteriorated quality of the feed river water.It has been proved that aggressive regeneration of ultrafiltration membranes that have worked for a long time under the conditions of feed water having increased values of the total microbial number and high values of permanganate oxidation does not allow one to restore their initial state. In this case the main cause of ultrafiltration membranes contamination is iron, which is present in colloidal and bacterial forms in the pores and on the membranes surfaces. In the conditions of the Novocherkasskaya RTPP, in addition to timely flushing and chemical regeneration of ultrafiltration membranes, the necessity of organizing a preliminary treatment of the feed water with reagents having a prolonged bactericidal effect is accepted.

Agro-Ecological Estimation of Various Fertilization Systems under Conditions of the Republic of Tatarstan

Producers of agricultural plants are increasingly marking a decrease in the responsiveness of cultivated plants to the mineral fertilizers applied to the soil. The explanation of this phenomenon can be the shift of limiting factors that determine the yield from mineral components in the soil to substances of organic and biological origin. The paper presents comparative data of the influence of mineral and organic fertilizer system on main biological indicators of the soil – nitrogen transforming groups of microorganisms, total microbial number (TMN), and soil respiration. The change in total and mineral nitrogen in the soil is estimated. The novelty of the study is that organic fertilizers are used in amounts comparable to the doses of mineral fertilizers in physical weight – 200 kg/ha. The application is carried out locally simultaneously with the seeding. As a result of the analysis, it has been found that ammonifiers (by 20.0–45 %), nitrifiers (by 30.0–46.7 %) numerically dominate in soil with organic fertilizers under all crops (corn, sunflower, soybean, sugar beet), the total microbial number is higher by 24.6–48.3 %. The intensity of carbon dioxide emissions (soil respiration) is also higher by 19.0–45.6 %. The intensity of biogeochemical processes in the soil and the related transformations of mineral nutrients, respectively and the provision of plants with them closely correlates with the number of valuable groups of microorganisms. The correlation coefficient between the number of ammonifiers and nitrifiers with the total nitrogen content in the soil under all studied crops in an organic fertilizer system is r=0.93.