Screening of microorganisms which are able to accelerate the process of microbial transformation of bird droppings

The purpose of the research. Screening of collection strains of microorganisms with enzymatic properties to accelerate the processes of microbial biodegradation of bird droppings. Research methods. The proteolytic activity of the grown cultures was studied according to GOST 20264.2-88, the total microbial number in the chicken droppings (CFU/ml) was analyzed, and the ammonium nitrogen was determined. Research results. As a result of the experiments, it was found that the highest proteolytic activity was demonstrated by the strain Pseudomonas putida 90 biovar A (171), which amounted to 74.6 units/g. When analyzing the effect of the studied collection strains on the decomposition processes of droppings, it was revealed that the largest number of microbial cells in bird droppings was achieved using Pseudomonas putida 90 biovar A (171), which was 104 CFU/ml at the beginning of the researches, and was the maximum and amounted to 1011 CFU/ml by the 15th day. The content of ammonium nitrogen in droppings treated with this culture decreased from 340 mg/l from the beginning of the experiment to 174 (15th day) and 169 mg/l (20th day) and it was the best indicator. When selecting the dose and concentration of the strain-producer Pseudomonas putida 90 biovar A (171) under introduction to bird droppings, it was found that to accelerate the process of biodegradation of bird droppings, the optimal dose for applying the studied culture is 4.0 % of organic waste mass with preliminary dilution by 2 times with water. At the same time, the optimal time of droppings keeping and the studied culture is 15 days. Scientific novelty. It was established for the first time that the treatment of chicken manure with the collection strain Pseudomonas putida 90 biovar A (171) accelerates the process of its microbial transformation.

Effect of Geobacillus toebii GT-02 addition on composition transformations and microbial community during thermophilic fermentation of bean dregs

Bean dregs can be prepared into organic fertilizer by microbial fermentation. Geobacillus toebii GT-02, which has promoting effect on bean dregs fermentation, was isolated from horse dung and it grows within a range of 40–75 °C and pH 6.50–9.50. The effectiveness of GT-02 addition on composition transformations and the microbial community in bean dregs thermophilic fermentation at 70 °C for 5 days was investigated (T1). Fermentation of bean dregs without GT-02 served as control (CK). The results showed that T1 (the germination index (GI) = 95.06%) and CK (GI = 86.42%) reached maturity (defined by GI ≥ 85%) on day 3 and day 5, respectively. In addition, the total nitrogen loss of T1 (18.46%) on day 3 was lower than that in CK (24.12%). After thermophilic fermentation, the total organic carbon and dry matter loss of T1 (53.51% and 54.16%) was higher than that in CK (41.72% and 42.82%). The mean microbial number in T1 was 4.94 × 107 CFUs/g dry matter, which was 5.37 times higher than that in CK. 16S rDNA sequencing identified Bacillus, Geobacillus and Thermobacillus as dominant in CK, while Bacillus, Ammoniibacillus and Geobacillus were dominant in T1. A canonical correspondence analysis showed that Geobacillus and Ammoniibacillus were positively correlated with the GI. Thus, thermophilic fermentation with GT-02 can promote the maturity of bean dregs, which indicated the potential application value of GT-02 in thermophilic fermentation.

SELECTION OF THE RATIO OF MICROBIAL COMPONENTS TO ACCELERATE THE BIODEGRADATION OF BIRD DROPPINGS

The aim of presented studies was to select the optimal ratio of the proteolytic culture of Pseudomonas putida 90 biovar A (171) and a strain that has the properties of fixing atmospheric nitrogen ‒ Azotobacter chroococcum 31/8 R to accelerate the process of biodegradation of chicken droppings to indicators of the relevant regulatory documentation. In conducted studies, the following indicators were analyzed: content of ammonium nitrogen, total microbial number, ammonia nitrogen, index of bacteria of the escherichia coli group, index of enterococci and pathogenic microorganisms, eggs and larvae of helminths, and the hazard class of processed and untreated chicken droppings was determined by the calculation method. As a result of conducted physico-chemical and sanitary-biological analyses, it was found that a more optimal and stable result was revealed when processing chicken droppings with the studied cultures in a ratio of 1:1. This treatment of droppings with cultures contributed to a 15-day decrease in the level of ammonium nitrogen in the by-product from 278 mg/l to 97 mg/l, the content of ammonia in the environment from 84 mg/m3 to 13 mg/m3, index of bacteria of the escherichia coli group from 4 to 1 units, index of enterococci from 5 to 2 units, index of pathogenic microorganisms from 2 to 0 units, number of eggs and larvae of helminths from 8 to 0 copies, number of larvae of synanthropic flies from 2 to 0 copies at the same time increasing the total microbial number to a value of at least 1011 cells/g. The hazard class of chicken droppings treated with microbial research objects decreased from III to IV and met the requirements of GOST 31461-2012.

Sanitary condition of soil in the territory of Astrakhan state technical university and nearby territories of higher educational institutions

Objective. The authors of this article studied and analyzed the sanitary condition of the soil in the territory of Astrakhan State Technical University and the nearby territories of higher educational institutions. Materials and methods. The study was carried out in May June 2019 on the basis of the laboratory of the Department of Infectious Diseases and Epidemiology of Astrakhan State Medical University and the laboratory of the Department of Applied Biology and Microbiology of Astrakhan State Technical University. Thirty soil samples were taken from these territories. The studies of soil samples for parasitological indicators were performed according to the guidelines "Control Methods. Biological and Microbiological Factors. Methods of Sanitary and Parasitological Research", for microbiological indicators "Methods of Soil Microbiological Control". Results. The following results were obtained: the sanitary-parasitological condition of the soil in parks near higher educational institutions in Astrakhan remains very tense as evidenced by positive findings of geohelminthoses; when assessing the degree of epidemic hazard of soil, there were identified nematode eggs and adult worm Strongyloids, that corresponds to the indicators of moderately hazard soil; the presence of live strongylid larvae in the studied samples indicates contamination of the soil with feces of infested animals, and the presence of Ascaris eggs indicates contamination of the soil with sewage or feces of infested children walking and resting in these territories; the total microbial number on average gave indicators for evaluating the selected soil samples as a slightly polluted soil. Conclusions. The sanitary and parasitological state of soil in parks of Astrakhan higher educational institutions remains rather tense as evidenced by positive findings of geohelminthoses.

Bacterial Number and Genetic Diversity in a Permafrost Peatland (Western Siberia): Testing a Link with Organic Matter Quality and Elementary Composition of a Peat Soil Profile

Permafrost peatlands, containing a sizable amount of soil organic carbon (OC), play a pivotal role in soil (peat) OC transformation into soluble and volatile forms and greatly contribute to overall natural CO2 and CH4 emissions to the atmosphere under ongoing permafrost thaw and soil OC degradation. Peat microorganisms are largely responsible for the processing of this OC, yet coupled studies of chemical and bacterial parameters in permafrost peatlands are rather limited and geographically biased. Towards testing the possible impact of peat and peat pore water chemical composition on microbial population and diversity, here we present results of a preliminary study of the western Siberia permafrost peatland discontinuous permafrost zone. The quantitative evaluation of microorganisms and determination of microbial diversity along a 100 cm thick peat soil column, which included thawed and frozen peat and bottom mineral horizon, was performed by RT-PCR and 16S rRNA gene-based metagenomic analysis, respectively. Bacteria (mainly Proteobacteria, Acidobacteria, Actinobacteria) strongly dominated the microbial diversity (99% sequences), with a negligible proportion of archaea (0.3–0.5%). There was a systematic evolution of main taxa according to depth, with a maximum of 65% (Acidobacteria) encountered in the active layer, or permafrost boundary (50–60 cm). We also measured C, N, nutrients and ~50 major and trace elements in peat (19 samples) as well as its pore water and dispersed ice (10 samples), sampled over the same core, and we analyzed organic matter quality in six organic and one mineral horizon of this core. Using multiparametric statistics (PCA), we tested the links between the total microbial number and 16S rRNA diversity and chemical composition of both the solid and fluid phase harboring the microorganisms. Under climate warming and permafrost thaw, one can expect a downward movement of the layer of maximal genetic diversity following the active layer thickening. Given a one to two orders of magnitude higher microbial number in the upper (thawed) layers compared to bottom (frozen) layers, an additional 50 cm of peat thawing in western Siberia may sizably increase the total microbial population and biodiversity of active cells.

Microbiota of the aquatic environment and rainbow trout when grown in the RAS

Fish production in closed systems is an intensive way of fish farming. However, keeping fish in plants with a closed water supply does not solve the problem of diseases in aquaculture facilities. The greatest damage is caused by bacterial diseases. In this regard, the study of the sanitary state of the aquatic environment of fish is relevant. The article provides information on the physicochemical parameters of water, the species composition of the microflora of the aquatic environment in the basin, microbiological indicators of the sanitary state of water, the total microbial count (TMC) and the number of bacteria of the E. coli group (BCGC) in the RAS when growing rainbow trout. Sanitary indicators of water quality in the pool, both in the first days of keeping rainbow trout, and after a week were within the normal range. There was only a numerical increase in the total microbial number and bacteria of the E. coli group in water samples taken after a week of finding the trout in the pools. According to the results of a study of the contamination of the skin and gills of rainbow trout, as well as the water in which it is contained, an increase in time was revealed from 69 to 73 CFU/ml on the skin and from 85 to 89 CFU/ml on the gills within a week. The qualitative composition of the microflora of the skin and gills of rainbow trout is represented by bacteria of the genera Aeromonas, Pseudomonas, Bacillus, Enterobacter, which is similar to the qualitative composition of the microflora of water. The study of the intestinal microflora of rainbow trout revealed that it also contains bacteria of the genera Aeromonas, Pseudomonas, Bacillus, Enterobacter. At the same time, lactic acid, streptococcal, staphylococcal bacteria, yeast-like fungi of the genus Candida were found, which are normal representatives of the intestinal microflora in small quantities.

Microbiological Activity during Co-Composting of Food and Agricultural Waste for Soil Amendment

This study aims to establish the relationship between ambient parameters and the diversity, composition, and function of microbial communities that predominate at each stage of the co-composting of food and agricultural waste. Culture-based and culture-independent methods were used to investigate the changes in the microbiota. The favorable conditions of high initial humidity and C/N ratio caused a decrease in the richness and biodiversity of the microbiota when such conditions existed. During the thermophilic stage, the total microbial number increased, and active mineralization of organic matter was carried out by members of the genera Bacillus, Caldibacillus, Aspergillus, and Penicillium. The fungal community was sensitive to drastic temperature changes. Byssochlamys dominated among fungi during the transition from the mesophilic to the thermophilic stage and during cooling. The biodiversity increased with time and was associated with the dynamics of germination and nitrification indices, so that the more diverse the microbial community, the higher the properties of compost that stimulate plant growth and development. The microbial community of the mature compost, together with mineral plant nutrients ready for consumption and humic compounds, make this compost a good soil additive.

The use of probiotics for the correction of disturbances of metabolism in cows

Currently, there is a huge range of different feed additives on the market, which are widely used in animal husbandry, but they act simultaneously, i. e. by stopping their use the resulting effect is also lost. Metabolic disorders due to feeding errors begin imperceptibly without any precursors, and first of all this affects the biochemical parameters of the blood only later leads to alimentary diseases with deep often irreversible degenerative changes in organs and tissues. In practice, there are rarely disorders of any one type of metabolism more often there are combinations of various metabolic disorders, especially often this occurs in the absence of a complete balanced feeding. The purpose of the work was to evaluate the effectiveness of the use of a probiotic drug based on Bacillus subtilis in the watering of lactating cows for the correction of metabolic disorders. In order to assess the actual presence of probiotics in the water during the experiment its analysis has been carried out. It has shown that in the water that enters the distribution tank the total microbial number was 9×10[sup]5[/sup] CFU/ml, and in the drinker this indicator was at the level of 3,8×10[sup]5[/sup] CFU/ml. Common coliform bacteria and thermotolerant coliform bacteria have been not detected. Studies have shown that when using the drug based on Bacillus subtilis containing five strains of bacteria in an amount of 0,01 %, which is 6 ml/head/day in the watering of lactating cows during the increasing the milk yield period there was a tendency to correct metabolic disorders. There was the decrease in the content of ketone bodies by 11,9 %, the increase in glucose by 34 % and the decrease in urea by 7,1 mmol/l.

Effect of Geobacillus toebii addition on composition transformations and microbial community in thermophilic bean dreg composting

A thermophilic bacterium, Geobacillus toebii GT-02, was successfully isolated from horse dung. The effectiveness of Geobacillus toebii GT-02 addition on composition transformations and the microbial community in bean dreg composting at 70°C for 5 days was investigated (T1), and the control consisted of bean dreg compost without GT-02 (CK). After 5 days, T1 presented higher total nitrogen contents (2.77%) and lower carbon-to-nitrogen ratios (14.4) than CK (2.34% and 16.9, respectively). The germination index (GI) of T1 was 135%, which was 56% higher than that of CK (86%). The dry matter loss in T1 was 54.16% (26.82% higher than the CK value (42.82%)). The mean microbial number in T1 was 4.94x107 CFUs/g dry matter, which was 5.37 times that in CK. 16S rDNA sequencing identified Bacillus, Geobacillus and Thermobacillus as dominant in CK, while Bacillus, Ammoniibacillus and Geobacillus were dominant in T1. A canonical correspondence analysis showed that Geobacillus and Ammoniibacillus were positively correlated with the GI. Thus, composting with GT-02 can promote the maturity of bean dregs, and GT-02 has potential commercial application in thermophilic composting.