Total Number Of Microorganisms Research Articles

Indigenous Lactic Acid Bacteria as Antioxidant Agents in the Production of Organic Raw Fermented Sausages

The study aimed to assess the impact of lactic acid bacteria (LAB) strains on the antioxidant, physico-chemical properties, and microbiological quality of fermented sausages. Five treatments of raw sausages were prepared: two controls without LAB addition (C, P), and three samples with LAB addition (SCH1, BAL6, KL14). Fatty acid composition, cholesterol content, physico-chemical, microbiological tests, and antioxidant assays, were performed at time 0 and after 1 and 2 months of storage. A significantly higher ability to scavenge free radicals of DPPH (2,2-diphenyl-1-picrylhydrazyl) was found in sausages with all LAB strains. In the case of the ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) test, it was noted that KL14 treatment had higher antioxidant activity. The main fatty acids in sausages were monounsaturated and saturated. A significantly lower cholesterol content was observed in sausages with the addition of LAB. Sausages with LAB strains differed significantly in pH value. Water activity decreased significantly during storage. After 2 months of storage, the sausages with BAL6 and KL14 strains were characterized by significantly lower redox potential and a lower TBARS (thiobarbituric acid reactive substances) index. It was found that P sausages had the darkest color. SCH1, BAL6, and KL14 strains were also capable of producing red color. The total number of microorganisms in the sausages was high, which is mainly due to the high LAB content and yeast and mold counts. No spoilage or pathogenic microflora were detected. Indigenous LAB strains have the potential to improve the quality and safety of fermented meat products.

Multitarget Phytocomplex: Focus on Antibacterial Profiles of Grape Pomace and Sambucus ebulus L. Lyophilisates Against Extensively Drug-Resistant (XDR) Bacteria and In Vitro Antioxidative Power.

Objectives: This study was conceived with the aim of translating the experience and knowledge of the research group into the design and creation of multi-active phytocomplex cocktails from lyophilised winery by-products (Grape Pomace-GP) and weeds (Sambucus ebulus L., Dwarf Elder-DE). Methods: Quantification of bioactive molecules was performed by high-performance liquid chromatography (HPLC) method. Results: In the extract obtained from lyophilised GP, the most dominant component that was quantified was petunidin-3-glucoside. Prominent compounds that were quantified in DE extract were cyanidin derivatives. The total number of microorganisms in lyophilisates is low, but some of them still survive lyophilisation. Antibacterial activity was determined by microdilution, the minimum inhibitory concentration (MIC) of the tested bacteria ranged from 0.78 mg/mL to 25.00 mg/mL. Antibacterial susceptibility testing (AST) revealed that Klebsiella spp. and Acinetobacter baumannii complex are extensively drug-resistant (XDR). Conclusions: The GP + DE cocktail showed very strong AB power against both tested XDR bacteria. The total phenolic content and antioxidative effect (determined spectrophotometrically) indicate their linear correlation.

The influence of phytoncidal properties of indoor plants on the air microflora of preschool educational organizations

BACKGROUND: The quality of indoor air is an important factor affecting health. AIM: To study the effect of phytoncidal properties of indoor plants on closed space under normal operating conditions of preschool educational institutions. MATERIAL AND METHODS: The dynamics of the microorganisms’ total number in the air of group rooms of preschool educational institutions was assessed according to current guidelines. The rooms were identical in area. The radius of phytoncidal action of indoor plants was determined. Air samples were taken after a week of exposure at different distances from a group of these plants in the breathing zone of children using an aspiration method with a sampling device. Statistical processing was carried out using the Statistica 10.0 and Microsoft Excel packages, ANOVA analysis of variance was applied. RESULTS: Plant species with phytoncidal activity were selected and designated (Chlorophytum comosum, Aspidistra elatior, Begonia ricinifolia, Hibiscus rosa-sinensis, Kalanchoe blossfeldiana, Plectranthus scutellarioides, Murraya exotica, Nephrolepis, Sansevieria trifasciata, Cyperus alternifolius). The total number of microorganisms in the air of group rooms before and after the installation of phytoncidal plants was compared (1201 and 584 CFU/m3). The maximum radius of plant placement at which bacterial contamination of the air decreased was determined. It was found that within a radius of 5 m from the placement of plants, the number of microorganisms was in the range of 380–481 CFU/m3, more than 5 m — 728–1101 CFU/m3. CONCLUSION: The use of indoor plants with phytoncidal activity in closed spaces of organized children's groups can serve as an additional way to improve the quality of the air environment.

Evaluation of Salmonella Contamination in Slaughtered Broiler Chickens in Slaughterhouses in Golestan Province, Iran

Background: Salmonella species are a primary pathogens of foodborne diseases, widely distributed in nature. Poultry is one of the essential known sources of Salmonella contamination. Slaughtering poultry in slaughterhouses can infect healthy poultry carcasses with Salmonella bacteria. Objectives: This study aimed to evaluate Salmonella contamination in slaughtered broiler chickens (SBCs) in slaughterhouses in Golestan province, Iran. Methods: To conduct the present study, 540 samples of SBCs were randomly selected from 12 chicken slaughterhouses in Golestan province, Iran. Frozen chicken samples were taken for analysis from January to March 2024. The national standard method of Iran (ISIRI) (No. 1810-1) was used to identify Salmonella in the selected samples. The total number of microorganisms (TNM) was counted using the surface counting method according to ISIRI (No.5272-2). Finally, the results were statistically analyzed by SPSS software version 22. Results: The results showed that Salmonella was not detected in any of the SBC samples, which indicates the outstanding quality of SBCs in terms of Salmonella. In addition, the average Log value of TNM was 2.81 ± 0.16 cfu/g, less than the permissible limit (log 10 cfu/g = 5 to 6) in all slaughterhouses and sampling months. Conclusions: The results showed that SBCs in Golestan province, Iran's slaughterhouses, are in good condition regarding microbial contamination. However, more studies are suggested to assess the different stages of the slaughterhouse more accurately regarding the presence and transfer of contamination to SBCs.

ИЗУЧЕНИЕ БИОЛОГИЧЕСКОЙ ПОЛНОЦЕННОСТИ СПЕРМАТОЗОИДОВ В СПЕРМЕ С БАКТЕРИАЛЬНОЙ ОБСЕМЕНЕННОСТЬЮ

The aim of the study is to investigate the relationship between bacterial contamination of bull semen and the biological value of spermatozoa, as well as reproductive performance. The object of the study was Holstein bulls (n = 17). The material for the study was frozen-thawed semen of bulls in the amount of 61 samples. Microbiological studies of sperm doses were carried out using standard nutrient media in accordance with GOST 32222-2013. The total number of microorganisms was calculated by the number of grown colony-forming units (CFU/ml) in 1 cm3, with subsequent determination of their morphological pro-perties. Sperm motility and morphology were determined using the Argus CASA program. The state of DNA in spermatozoa was studied by the acridine orange test (AO test) using a fluorescence microscope. The study revealed a high positive correlation (r = +0.940**) between the number of microorganisms in sperm and pathology in individual sperm segments. Analysis of variance confirmed a statistically significant effect of the number of microorganisms on sperm morphology F = 123.2 (p=0.000). The correlation relationship between the fragmentation index and the content of microorganisms has a high value (r = +0.965**). Sperm motility negatively correlates (r = –0.768**) with the number of microorganisms (CFU/ml). In the presence of Mycoplasma spp in the samples, the number of cows with fruitful insemination was 35.5 % due to reduced motility, morphology and high fragmentation of sperm DNA (58 %). Sperm motility in samples containing Mycoplasma spp averages 24.5 %, while in samples without these microorganisms it is 48.9 %. Thus, it can be assumed that the presence of Mycoplasma spp in samples and high bacterial contamination rates lead to to lower reproductive performance in bulls.

Response of Arugula to Integrated Use of Biological, Inorganic, and Organic Fertilization.

This study evaluated the effects of solely and integrated application of inorganic (NPK), commercial organic (NC), and biological (MIX, mixed strains Ensifer meliloti and Azotobacter chroococcum) fertilizers on the chemical characteristics of arugula biomass and its yield, as well as changes in soil microbiological parameters after the experiment in relation to the control treatment (Ø). The experiment was performed in semi-controlled greenhouse conditions, in pots, from the 4th decade of March to the 2nd decade of September, in 2023, at three cutting times/swaths, during one agricultural season, with Vertisol soil. For soil characterization, the following parameters were analysed: granulometric composition using sieving and sedimentation procedure; soil acidity-potentiometrically; SOM-soil organic matter by Kotzmann method; total N using CNS analyser; available P-spectrophotometrically; available K-flame photometrically; total number of microorganisms on an agarized soil extract medium; fungi on a solid Czapek agar; actinomycetes on a solid Krasiljnikov agar with saccharose; Azotobacter spp. on a liquid Fyodorov medium with mannitol; ammonifiers on a liquid medium with asparagine; and dehydrogenase activity-spectrophotometrically. For plant characterization, the following parameters were determined: N and C, both on CNS analyser; P on spectrophotometer; K on flame photometer; air-dried yield biomass. A stimulative effect on all microbiological parameters was found in the treatment with integrated use of organic and biological fertilizer, except for fungi, which grew better in the treatments with separate inorganic and organic fertilizers. Generally, the stimulative impact on plant chemical parameters manifested in combined inorganic and biological, organic and biological, and inorganic and organic fertilization treatments, and was inhibited in treatment without fertilization, in all three swaths, which could also be stated for the plant yield. Positive influence of all fertilization treatments on chemical parameters was observed for the second swath in relation to the first and the third. The total yield in the NPK+MIX treatment was 121%, and in the NC+MIX treatment, it was 87% higher compared to the control (Ø). In general, integrated use of inorganic and biological, organic and biological, and inorganic and organic fertilizers, respectively, could be proposed as an optimal fertilization treatment in arugula cultivation.

The Effect of Apple Vinegar Addition on the Quality and Shelf Life of Cooked Sausage during Chilling Storage

As more and more consumers are becoming conscious of the safety and taste of meat products, the use of natural additives and innovative processing techniques has gained significant attention. Naturally fermented fruit vinegar is rich in organic acids and antioxidant phenolic compounds. In addition, it contains amino acids, minerals, vitamins, and provitamin beta-carotene, and the presence of acetic acid bacteria may have a positive effect on consumer health. The study aimed to assess the impact of different concentrations of apple vinegar addition on the quality of cooked sausage, focusing on physicochemical parameters, including fatty acid profile and oxidative stability, as well as microbiological quality and sensory changes after production and during chilling storage. Four variants of sausage were prepared: C—sausage without apple vinegar; V1—sausage with 1% of apple vinegar; V3—sausage with 3% of apple vinegar; and V5—sausage with 5% of apple vinegar. All of the tests were carried out after production, as well as after 7 and 14 days of refrigeration storage. The addition of apple vinegar decreased the pH value and increased the oxidation-reduction potential and lipid oxidation in the samples V1, V3, and V5. The sausage with the 5% addition of apple vinegar (V5) was characterized by significantly more intensive brightness (parameter L* = 54.67) in comparison to the C sample (parameter L* = 52.78). The sausages that were tested showed good microbiological quality concerning the total number of microorganisms, lactic acid bacteria, and the absence of pathogenic bacteria. The addition of apple vinegar contributed to the reduction in the intensity of the cured meat flavor and the fatty flavor. Therefore, according to the results presented in this work, it can be concluded that 3% of vinegar is the optimal addition, which may be used in the next step of investigation, taking into account color formation abilities as well as microbiological quality and lipid oxidation processes.

Reduction of microorganisms in carious dentin by photodynamic therapy mediated by potassium iodide added to methylene blue and red laser

ObjectiveTo evaluate the effect of the association of potassium iodide to antimicrobial photodynamic therapy on human carious dentin produced with a microcosm biofilm model. MethodsA microcosm biofilm model was used to generate a caries lesion on human dentin. Pooled human saliva diluted with glycerol was used as an inoculum on specimens immersed on McBain artificial saliva enriched with 1 % sucrose (24 h at 37 °C in 5 % CO2). After refreshing culture media for 7 days, the dentin specimens were divided in 5 groups (3 specimens per group, in triplicate; n = 9): C (NaCl 0.9 %), CX (2 % chlorhexidine), PKI (0.01 % methylene blue photosensitizer+50 mM KI), L (laser at 15 J, 180 s, 22.7 J/cm2), and PKIL (methylene blue + KI + Laser). After the treatments, dentin was collected, and a 10-fold serial dilution was performed. The number of total microorganisms, total lactobacilli, total streptococci, and Streptococcus mutans was analyzed by microbial counts (CFU/mL). After normality and homoscedasticity analysis, the Welch's ANOVA and Dunnett's tests were used for CFU. All tests used a 5 % significance level. ResultsCX and PKIL groups showed significant bacterial decontamination of dentin, compared to group C (p < 0.05) reaching reductions up to 3.8 log10 for CX for all microorganisms’ groups and PKIL showed 0.93, 1.30, 1.45, and 1.22 log10 for total microorganisms, total lactobacilli, total streptococci, and S. mutans, respectively. ConclusionaPDT mediated by the association of KI and methylene blue with red laser reduced the viability of microorganisms from carious dentin and could be a promising option for cavity decontamination.

Impact of Inoculation of rumen fluid of Awassi lambs with ruminal fluid of Iraqi buffalo on in vitro digestion of Iraqi wild Reeds and some ruminal fluid characteristics

The study was conducted at the College of Agricultural Engineering Sciences / University of Baghdad for the period from 3-30-2022 until 4-10-2022 to determine the extent of improvement or change in the rumen fluid of Awassi lambs after inoculation with Iraqi buffalo rumen fluid, and 5 different percentages of Iraqi buffalo rumen fluid were used. Which was collected immediately after slaughter and (0.1, 0.2, 0.4, 0.6, and 0.8) represented the parameters (T1, T2, T3, T4, and T5). It was added to the rumen fluid of Awassi lambs in in vitro digestion tubes to estimate the in vitro digestibility coefficient for the dry and organic matter of the Iraqi wild Reeds, pH, and total number of microorganisms in rumen fluid. The results showed a highly significant increase (P&lt;0.01) for the two treatments (T4 and T5) in the in vitro digestibility coefficient of organic matter and dry matter compared to the treatments (T1, T2, and T3). While the digestibility coefficient of organic matter improved significantly compared to dry matter. The pH values recorded a highly significant increase (P&lt;0.01) after 9 and 12 hours for all treatments compared to their values after 6 hours of in vitro digestion. The results showed a highly significant (P&lt;0.01) superiority of the two treatments (T2 and T4) with buffalo rumen fluid in the pH values compared. With parameters (T1, T3, and T5) with different times during which the pH was measured. The treatments (T3, T4, and T5) were highly significantly (P&lt;0.01) superior in terms of the total number of microorganisms compared to the two inoculation treatments with buffalo rumen fluid (T1 and T2), while the two inoculation treatments (T3 and T5) recorded a highly significant (P&lt;0.01) superiority in The total number of microorganisms in rumen fluid compared to other treatments. From the results achieved above, we conclude that the treatments (T3, T4, and T5) are considered the best rates for inoculation with buffalo rumen fluid, and the T4 treatment is considered the best compared to other inoculation treatments.

Effect of inoculating the Awassi rumen fluid with its counterpart from Iraqi buffaloes on in vitro digestibility coefficient of barley straw and some characteristics of the rumen fluid

The study was conducted at the College of Agricultural Engineering Sciences / University of Baghdad for the period from 3-30-2022 to 4-10-2022 with the aim of determining the extent of improvement or change in the rumen fluid of Awassi lambs after inoculation with Iraqi buffalo rumen fluid. 5 ratios of Iraqi buffalo rumen fluid were used. Which was collected immediately after slaughter and (0.1, 0.2, 0.4, 0.6, and 0.8) represented the treatments (T1, T2, T3, T4, and T5) were added to the rumen fluid of Awassi lambs in in vitro digestion tubes to estimate the in vitro digestibility coefficient of the dry and organic matter of barley straw, pH, and total number of microorganisms in rumen fluid. The results showed a highly significant improvement (P&lt;0.01) for the treatments (T3, T4, and T5) in the in vitro digestibility coefficient of organic matter and dry matter compared to the two treatments (T1 and T2). The results also indicated a highly significant (P&lt;0.01) superiority in the pH value of the two treatments (T2 and T4) with buffalo rumen fluid compared to the other treatments depending on the timing during which the pH was measured. In the same context, the treatments (T3, T4, and T5) outperformed the total number of microorganisms, and the results showed highly significant differences (P&lt;0.01) for the two treatments (T3 and T4) in the total number of microorganisms compared to the treatments (T1, T2, and T5).From the results achieved above, we conclude that the two treatments (T3 and T4) for inoculation with buffalo rumen fluid were significantly superior in improving the in vitro digestibility coefficient of dry and organic matter and improving the characteristics of the rumen fluid in light of the results achieved above. This study is one of the first studies to improve the rumen environment in Awassi lambs through inoculation with different proportions of rumen fluid taken from Iraqi buffaloes after slaughter.

Microbiological substantiation of the effectiveness of quercitin and its combination with ethylmethylhydroxypyridine succinate in the complex treatment of odontogenic phlegmon and maxillofacial abscesses.

The cross-sectional study included 75 patients. Purulent exudate was collected from the infection site. The number of colony-forming units was counted using the standard plate method. The microbiological examination of purulent exudate obtained from the patients revealed the general prevalence of Gram-positive cocci. On the seventh day of treatment, the total number of microorganisms in the purulent exudate of patients in group I, whose treatment included a combination of the standard protocol with quercitin, significantly decreased compared to the first day of the same group. The results of treatment of patients in group II, which included the standard protocol in combination with quercitin and 2-ethyl-6-methyl-3-hydroxypyridine succinate, demonstrate a significant decrease in the total number of bacteria in the infection focus on the fifth day of treatment compared to this indicator of the group at the beginning of the study. When quercitin was used as part of complex treatment, the total treatment period was reduced by 1.4 days. However, the combined use of quercitin and ethylmethylhydroxypyridine succinate against the background of standard treatment of patients with odontogenic infection contributed to a reduction in hospital stay by 2 days.

Combined effect of cover crops and bio-fertilizer on sustainable popcorn maize production.

Cover crops play an important role in low-input cropping systems, increasing the use of agro-ecosystem services. Due to the lack of information about the impact of cover crops and bio-fertilizers on popcorn maize (Zea mays everta Sturt.) growth and yield quality, especially the popping volume and nutritive quality, such as concentrations of protein and mineral elements, this research aimed to provide essential information. The interrelation between popcorn maize productivity and quality with important groups of soil microorganisms presents additional novelty. The results demonstrated that field pea is a beneficial cover crop, especially when combined with a bio-fertilizer, supporting the accumulation of maize biomass, chlorophyll, yield potential, and the concentrations of protein, Ca, Mg, Fe, and Zn. In addition, field pea residues promoted N-fixing bacteria, and the number of total microorganisms, especially actinomycetes and decomposing bacteria, which could promote nutrient uptake and grain quality. Residues of cover crop mixtures, common vetch + winter oats and field pea + winter oats, promoted the total number of microorganisms in the soil, and up to the end of vegetation, a greater number of decomposition and ammonification microorganisms were found, especially when the bio-fertilizer was applied, which consequently could support greater maize biomass. Popping volume, as a main trait of popcorn maize, had the highest value in the common vetch + winter oats variant, supporting again the statement that quality traits could be enhanced in sustainable production. Unlike living cover crops, mulch mainly affected soil microbial communities and promoted the development of actinomycetes and cellulolytic microorganisms during the growing season. The results of this research could contribute to the development of sustainable popcorn maize production for improved grain quality. They could also serve as a basis for isolating beneficial soil microorganisms to develop new bio-fertilizers that could improve maize production in synergy with cover crops.

EFFECTS OF THE LONG-TIME RIPENING OF BEEF UPON ITS QUALITY PARAMETERS

Subject. The subject is beef obtained from young bulls of the Aberdeen-Angus beef breed. Purpose. The purpose is to investigate the effects of dry ripening of beef upon its quality and safety parameters. Methods. The content of protein (by mass) was determined by the content of total nitrogen according to Kjeldahl followed by distillation of ammonia; the content of water (by mass) – by drying the portion to constant weight at the temperature of 105ºС; content of fat (by mass) – Soxhlet method; pH – potentiometric method; water-binding ability – by pressing the test sample; sensorial parameters – consumer assessment using a hedonic scale of 9 levels; rheological parameters – using a universal electromechanical testing machine; microbiological parameters – based on the total number of microorganisms in 1 g of product. Results. The quality parameters of long-ripened meat (within 21 days) were studied in comparison with traditionally ripened meat (within 5 days). Sensorial assessment has shown the benefits of long-ripened meat. It was found that in long-ripened beef samples the content (by mass) of protein and fat is higher by 12.97% and 21.41%, respectively; water-binding capacity is 10.69% higher. This leads to a reduction in meat moisture loss during heat treatment by 6%. It has been determined that the penetration force of long-ripened meat is less important compared to similar parameters of traditionally ripened meat. Microbiological studies have shown that meat on the 21st day of ripening corresponds to standard values. Scope of results. A technological instruction for the production of fermented meat has been developed. The developed solution was tested in industrial conditions, and a production inspection certificate was obtained.

The role of pre-disinfection measures in reducing the microbial load of pig house facilities

Premises for keeping animals and objects in them are constantly exposed to significant contamination with organic substances, substantially impacting the disinfection quality. To achieve its maximum effectiveness, it is essential to consistently perform pre-disinfection measures that create optimal conditions for the destruction of microorganisms. However, due to a lack of awareness, poor risk management, time and resource constraints, and lack of systematic controls, many livestock producers underestimate the importance of pre-disinfection measures, which include mechanical cleaning, detergent treatment, hydro-cleaning, and drying. Improper implementation or complete absence of pre-disinfection measures can create favorable conditions for the development of pathogenic microorganisms, which threatens the health and productivity of animals. The work aimed to establish the effect of pre-disinfection measures on the microbial load of piggery facilities. As a result of the conducted research, it was established that before the pre-disinfection measures were carried out at the facilities of pig farms, the total number of microorganisms in honey was from 5.12 ± 0.49 to 6.83 ± 0.54 log CFU/cm3 of washing. The least covered with microflora were feeding troughs, 5.5 % more feeders, 17 % walls, 19 % intercellular partitions, and 25.1 % floors. Carrying out mechanical cleaning of the researched objects of animal husbandry premises ensured a reduction of microflora on their surface from 1.6 to 8.1 % and treatment with the “Grass” agent – from 15.3 to 18.5 %. A decrease in the amount of microflora from 23.7 to 30.9 % on the floor, inter-cage partitions, walls, feeders, and drinking troughs was established after their hydro-cleaning with the high-pressure device “Aqua Master”, and the specified differences were probable (P &lt; 0.05). It has been proven that the proper implementation of all stages of pre-disinfection requirements leads to a possible (P &lt; 0.05) decrease in the microbial load, which was 28.7 % on the floor, 38.3 % on the intercellular partitions, 36.1 % on the walls, 32.0 % in the feeders, 8 %, and 34 % on water supply.

Assessment of Water Suitability for Drinking in the Spring in Leśniów (Southern Poland)

Abstract Natural springs are one of the potential sources of water supply. Increasing anthropogenic activity, inadequate sanitary conditions and intense rainfall are important factors that threaten the maintenance of adequate water quality in springs. Physicochemical and microbiological tests were performed in two measurement series for water from the spring in Leśniów (southern Poland). The test results were compared with the permissible limits for drinking water and the Nemerow Pollution Index (NPI) value was calculated for these parameters. The average conductivity of water in this spring is approximately 390 µS/cm, pH is about 7 and due to its alkalinity, water can be classified as hard. The NPI values varied, i.e. from about 33 to about 3, which was due to the high mercury content measured in the first sample. Additionally, the number of coliform bacteria reached 35 cfu/100 ml, and the total number of microorganisms at 22±2°C reached 27 cfu/ml in the first measurement series. Such values indicate water contamination, which may pose a significant threat to human health when consuming such water. The second series of measurements showed lower pollution values, but the previously obtained results suggest that it is necessary to control the water quality in the springs and control nearby pollutant emitters.

Current state of bacterioplankton of Lake Ilmen

Objective: Determination of the quantitative level of the Lake Ilmen bacterial community in a retrospective. Assessment of lake water quality by microbiological indicators based on the results of seasonal microbiological studies in 2022Research material and methods used: The material was samples of bacterioplankton from the surface water layer of the Lake Ilmen, collected in May, August and September 2022. The total numbers of microorganisms was determined by the epifluorescence method using DAPI fluorochrome. Standard methods were used to determine the number of saprophytic microorganisms at two temperature regimes.Originality: For the first time in the last 25 years, the quantitative characteristics of the bacterial community of Lake Ilmen were determined. A quality assessment of lake waters has been carried out, and the values of self-purification coefficients were calculated.Results: The microbiological characteristic of the water masses of Lake Ilmen, as a habitat for bioresources, is presented. The maximum values of the total bacterial numbers (TBN) were observed in May (average 5.05±0.52×106 cells/ml) during the spring flood, the minimum — at the end of September (average 3.21±0.89×106 cells/ml) during the cooling period of the lake. Coccoid cells prevailed in the bacterioplankton, which indirectly indicates the absence of contamination of the lake waters with organic matter of various origins. According to the average for the observation period TBN (4.10±1.05×106 cells/ml), the trophic state of the lake corresponded to weakly eutrophic. The number of saprophytic bacteria growing at 22 °С always exceeded that at 37oC, which indicated active self-purification processes. According to the quantitative ratios of the TBN and the number of saprophytic bacteria growing at 22 °С (OMH 22 °С), the water masses of the lake, with rare exceptions, belonged to the conditional category of “pure” (oligosaprobic)

Physicochemical characteristics and sensory preference of chicken ball with unripe jackfruit

This study evaluated the physicochemical and sensory characteristics of chicken balls substituted with unripe jackfruit (JF). The JF was sliced, boiled, chopped, and substituted at 0, 50, 100, and 150 g/kg of boneless breast. The mixtures were processed, and the meat batter and chicken balls were measured in properties. Increasing levels of JF resulted in decreased lightness, redness, and yellowness values of meat better and chicken balls. Texture profile analysis showed that increasing levels of JF resulted in lower stickiness and cohesiveness of the meat batter and lower hardness and springiness values of the chicken ball. Sensory evaluation showed that chicken balls with JF at 100 g/kg had preference levels for overall acceptability that were not significantly different. Thus, the chicken balls with JF at 100 g/kg substitution was chosen for proximate analysis and microbiology testing. An analysis of the chemical composition of the chosen chicken balls substituted found that the moisture, protein, fat, crude fibre, ash, and carbohydrate contents were 77.44, 11.80, 0.53, 14.28, 2.12, and 6.09%, respectively. The total number of microorganisms was 1.9 × 102 colonies/g. These final chicken balls were safe. This study demonstrated that JF could be substituted in meat emulsion to produce appropriate chicken balls.

GAS COMPOSITION AND MICROORGANISMS OF GROUND ICE IN RUSSIAN ARCTIC

Link for citation: Butakov V.I., Slagoda E.A., Zavatsky M.D., Ivanov V.I. Gas composition and microorganisms of ground ice in Russian Arctic. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 9, рр. 63-75. In Rus. Relevance. The increase in the concentration of greenhouse gases in the atmosphere is a fundamental problem on a planetary scale. The source of greenhouse gases in the subsurface horizon of soil can be both deep deposits of hydrocarbons and organic matter processed by microorganisms during the thawing of the ice-rich soil. To determine the source of the gas it is necessary to examine both its quantity and composition and the microorganism content in the subsurface ice. Taking into account the dynamic development of the energy complex in the north of Western Siberia it is necessary to take into account the geotechnical risks associated with the release of greenhouse gases from frozen deposits. Purpose: to study the composition and identify the sources of greenhouse gases in the ice and the ice-rich soil on account of the ice formation conditions and the microorganism content. Objects: ice wedge, hydrogenic and segregational genesis of ice, ice-rich soil of northern Western Siberia and Central Yakutia, collected by expeditions Earth Cryosphere Institute, Tyumen scientific center SB RAS in 2011–2021. Methods of research and interpretation of chemical composition. The structure of frozen deposits has been investigated by cryolitological methods. The monoliths of the ice and the frozen deposits were stored at –18 °C. Gas was extracted from the monoliths with the determination of volume fraction by thermovacuum degassing method. The composition of gases is determined by gas chromatography. Normalization of the gas composition with solubility values in water was carried out. Volume fractions of gas in free and dissolved forms was calculated. The data processing were implemented by means of «Geochem Anomaly» program. Cultivated psychrophilic microorganisms were studied by seeding on nutrient media; the total number of microorganisms was determined by epifluorescent microscopy. Results. The contents of N2 (74,9–87,8 %), O2 (11,7–20,3 %), CO2 (0,01–3,28 %), CH4 (0,003–7, 35 %), H2 (0,001–0,035 %) and hydrocarbons with an atom content from 2 to 6 (2,0×10–5–2,8×10–3 %) are determined in ice and ice-rich soil. The value of N2 and O2 in the gas composition of ice is close to atmospheric air. The ice has wide variations in gas saturation (1,1–21,1 %), CH4 and CO2 content. The freezing of gas-saturated solution occurred for the ice formation, part of the air was in a free form (from 30 to 75 %). Calculated indexes CH4/(C2H6+C3H8) and C2H6/C2H4 indicate biogenic hydrocarbon genesis. The composition of gas bubbles is recalculated for the volume of the entire sample: CH4 content is insignificant in ice wedge, closed-cavity ice and icing (averages 51, 81 and 1 ppmV, respectively). The low amounts of CH4 could be produced by forming these types of ice from the sediments of the active layer, as the dependence of the gas composition on the peat element amount is established. CH4, CO2 and H2 contents increased in samples with peat elements. In interbedding ice the CH4 content is high (216 ppmV). CO2 (up to 3007 ppmV) was accumulated in the texturing ice, and hydrogenic wedge-shaped ice showed high levels of CH4 (up to 4032 ppmV) as the ice was frozen in an enclosed volume. The ice of peat mound has a maximum content of CH4 (15545 ppmV) and high CO2 (2466 ppmV); inclosing sediments flooded with marginal-marine waters are the source of high values of CH4 and CO2. The cultivated psychrophilic microorganisms were identified in the surface ice, and their maximum quantities were identified in segregated formations – up to 1680 KOU/ml, in textural ice – up to 1032 KOU/ml. High concentrations of greenhouse gases are found in frozen peat – CO2 (1075 ppmV), H2 (9 ppmV), CH4 (262 ppmV) and other hydrocarbons due to activity of microorganisms, which results in accumulation of these gases. High gas saturation and CH4 and CO2 levels indicate the formation of gaseous composition by both aerobic and anaerobic microorganisms.

Effects of multi-frequency ultrasonic assisted sodium hypochlorite on the cleaning effect and quality of fresh-cut scallion stems

This study aimed to evaluate the feasibility of multi-frequency ultrasound-assisted sodium hypochlorite (NaClO) on fresh-cut scallion stem (FCS) cleaning. Ultrasonic cleaning parameters (frequency mode, frequency amplitude, and the sample to water ratios) were optimized against cleanliness and microbial biomass as evaluation indexes. Under the optimum conditions, the free chlorine residues and quality attributes of FCS were also investigated. The results showed that the cleanliness of FCS improved significantly (p < 0.05) and the total number of microorganisms, especially Escherichia coli, decreased dramatically under the optimized cleaning condition with the simultaneous ultrasound (US) at the sweep frequency (SF) combination of 20 + 28 kHz, the ultrasonic density of 60 W/L, pulse time of 10 s, which indicated that the shelf life of FCS would be extended. Compared to FCS after the 250 ppm NaClO cleaning, the retention of ascorbic acid (AA), color, and texture structure of FCS had no significant difference after ultrasound-assisted NaClO treatment. Meanwhile, the content of allicin increased by 52.5% under ultrasound-assisted cleaning. The integration of US into the cleaning process resulted in a notably reduction of 68% in NaClO concentration, as well as the weight loss and respiration rate (RR) of the scallion stems. Therefore, ultrasound-assisted NaClO cleaning was regarded as a promising and effective approach for cleaning fresh-cut vegetables.

The effect of form and method of flavoring on microbiota of olive oil.

Flavoring olive oil is an increasing trend in olive oil processing. Growing consumer interest in flavored olive oils by natural material brings the need to evaluate the key limiting factors which is its microbiological stability. The present research compares the microbiological quality of olive oil flavored by 3 flavors (rosemary, garlic, and lemon), prepared by 3 methods to determine changes during storage. The comprehensive microbiological analyses (total number of microorganisms [TCM], anaerobic sporulates, yeasts, molds, bacteria of the family Enterobacteriaceae, bacteria of the genus Salmonella spp., Clostridium botulinum, and lactic acid bacteria) were conducted during 12 months of storage. The best results in TCM were observed in the oil flavored by fresh garlic (0.24 log CFU/mL). The highest counts of anaerobic sporulates were detected in the dried rosemary olive oil (1.10 log CFU/mL). The flavoring materials have significantly higher counts of microorganism than flavored oils (p < .05). The obtained results demonstrated that microorganisms are capable to survive in flavored olive oil and the method of flavoring can affect their growth in a selective way according to the chemical characteristics.