Background: Copper is a mineral that is involved in many functions og the human body and copper has antibacterial reaction. However many scientists have studied the antibacterial activity of nano copper, in our country, the lack of research is the basis of our research. Aim: Determination of antibacterial activity of colloidal copper (CuNP) Materials and Methods: The study protocol was reviewed and approved by the Research Ethics Review Committee of the Mongolian National University of Medical Sciences on February 18, 2022 (Protocol No. 2022/3-02). An ionized copper solution was produced by passing an electric current (19–20 V, 3–5 A, for 24 h) through sterilized distilled water using copper plates. Ascorbic acid was then added to prepare colloidal copper. The concentration was determined using a PPM meter, and the solution was filtered through a 0.22 µm bacterial filter. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against standard bacterial strains were determined by the broth dilution method. To determine the bactericidal time, bacterial cultures were exposed to the bactericidal concentration and subcultured hourly for 10 hours. Additionally, antibacterial activity was evaluated on Mueller–Hinton agar using the disk diffusion method according to CLSI standards, where 20 µL of colloidal copper was applied onto antibiotic disks. The plates were incubated at 37°C for 24 hours, and the diameter of the inhibition zones was measured. Result: The concentration of the prepared colloidal copper was 0.7 ppm. Using the broth dilution method, complete bactericidal activity was observed at 0.006 ppm against Klebsiella pneumoniae, Escherichia coli, and Salmonella enteritidis, while Pseudomonas aeruginosa was completely killed at 0.008 ppm. In terms of exposure time, complete bacterial killing occurred after 2 hours for S. enteritidis and K. pneumoniae, after 6 hours for E. coli, and after 11 hours for P. aeruginosa. In addition, antibacterial activity was evaluated on Mueller–Hinton agar using the disk diffusion method according to CLSI standards. Colloidal copper increased the inhibition zone diameter of most antibiotics by 1–5 mm, particularly against P. aeruginosa. In K. pneumoniae, the activity of aztreonam and ceftriaxone was enhanced. When evaluating the inhibition zone diameter of cefotaxime against E. coli, the susceptibility result changed from intermediate to susceptible, while no significant change was observed for the other antibiotics tested. For K. pneumoniae, the addition of colloidal copper increased the inhibition zone diameter of aztreonam and ceftriaxone by approximately 1–2 mm. In P. aeruginosa, the inhibition zone diameters of most antibiotics increased by 1–5 mm; however, the activity of imipenem decreased. For S. enteritidis, most antibiotics showed an increase in susceptibility of approximately 1–2 mm, while ceftriaxone showed no observable effect. Conclusion 1. Colloidal copper solution, at low concentrations, exhibits bactericidal activity against some Gram-negative rod-shaped bacteria. 2. Colloidal copper solution shows a synergistic effect with certain drugs, enhancing their activity; however, it exhibits an inhibitory effect on the activity of imipenem.

Background: Numerous international studies have established that the antibacterial activity of honey is attributed to its key components, including hydrogen peroxide, methylglyoxal, peptides, polyphenolic compounds, high sugar content, and acidic pH. Despite the vast consumption of different types of honey in Mongolia, there is a lack of sufficient scientific evidence on their antibacterial properties, which served as the rationale for conducting this study. Aim: A study comparing the antibacterial activity of honey commonly traded in Mongolia. Materials and Methods: The study was conducted using an experimental research design. Eight standard pathogenic bacterial strains were utilized: Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 1706, Staphylococcus aureus ATCC 25923, Methicillin-resistant Staphylococcus aureus (MRSA) ATCC 700699, Staphylococcus epidermidis ATCC 35984, Salmonella enterica ATCC 13076, and Acinetobacter baumannii ATCC 19606. A total of 14 honey samples were selected for the study, comprising 11 samples sourced from the Uvs, Tuv, Sukhbaatar, Khentii, Dornod, Darkhan, Selenge, and Khuvsgul provinces of Mongolia, and 3 Manuka-type honey samples from Australia. The samples were serially diluted in broth using a 96-well U-bottom microtiter plate. One microliter of each bacterial suspension was added, and the plates were incubated at 37°C for 18–24 hours. Subsequently, the cultures were spread onto Mueller-Hinton agar and incubated under the same conditions. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by evaluating bacterial growth inhibition and bactericidal activity, respectively. Result: Among the tested samples, the Manuka honey with MGO 570 and the honey collected from Tumentsogt soum in Sukhbaatar province exhibited the most potent antibacterial activity against MRSA, with a minimum inhibitory concentration (MIC) of 12.5% (v/v) and a minimum bactericidal concentration (MBC) of 25% (v/v). In contrast, the antibacterial activity of Manuka honey with UMF 5 and the honeys sourced from Tuv, Uvs, and Khalkhgol soum in Dornod province demonstrated MIC and MBC values of 25% (v/v) and 50% (v/v), respectively. The Manuka honey with MGO 30, as well as the honeys collected from Selenge, Darkhan, Sukhbaatar, Khentii, and Rashaant and Tarialan soums in Khuvsgul province, showed comparatively weaker activity against MRSA, Salmonella enterica, Staphylococcus epidermidis, Escherichia coli, and Staphylococcus aureus. Conclusion 1. The antibacterial activity of natural and cultivated floral honeys was assessed by determining their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against eight standard bacterial strains. 2. All seven natural floral honey samples exhibited measurable antibacterial effects against the tested strains, whereas some of the cultivated floral honey samples showed no observable activity against certain bacterial strains.

Background: Research on lactic acid bacteria has confirmed how specific strains possess probiotic properties and impart unique sensory characteristics to food products. The use of probiotic lactic acid bacteria in many food products, thus confers various health benefits to humans when they are frequently consumed in adequate amounts. Aim: To determine the effect of lactic acid bacteria on the growth of tomatoes. Materials and Methods: The lactic acid bacteria were cultured using the Lactobacillus medium from whipping cream and Dandelion (Taraxacum mongolicum) and identified using the MALDI-TOF MS automated microbial identification analyzer. A solution was prepared using Lactobacillus delbrueckii isolated from whipping cream and Lactobacillus gasseri isolated from Dandelion (10^7CFU/ml), and sterilized tomato seeds were watered for 10 days with the solution, while sterilized distilled water was used as a control. The germination rate of the seeds and the root length were measured and recorded every day. Results: The solution of L.delbrueckii bacteria isolated from cream germinated 100% of the seeds, which is 4% higher than the control seeds, while the solution of L.gasseri bacteria isolated from Dandelion germinated 100%, supporting 4% higher than the control seeds. Seedlings irrigated with the L.delbrueckii bacterial solution exhibited an average length of 10.3cm, which was 1.3cm longer than the control (P=0.003), indicating a statistically significant difference. Similarly, those treated with the L.gasseri solution had an average length of 11.5cm, 2.5cm longer than the control (P=0.005), also demonstrating statistical significance. Conclusion The application of the lactic acid bacterial solution significantly enhanced both the germination of tomato seeds and the growth of the plants compared to the control solution.

Background: This study explores the potential of food industry by-products, such as plant peels, stems, and slags, as valuable sources of lignocellulosic material (LCM), which contains 25-40% xylan. These underutilized resources, often discarded as waste, hold the promise of sustainable applications in biotechnology. By safely extracting xylooligosaccharides (XOS) from LCM biomass, the value of these materials can be significantly enhanced, contributing to green production and supporting sustainable development. XOS, recognized for its prebiotic activity, has been shown to promote the growth of beneficial gut bacteria, making it a vital research area in the fields of food science, medicine, and technology. Aim: To extract and characterize oligosaccharides derived from by-products of the food industry, evaluate their physicochemical properties, and investigate selected biological activities. Materials and Methods: This study utilized microwave pretreatment and enzymatic hydrolysis to isolate and purify XOS from wheat bran and brewers’ spent grains (BSG), provided by Altan Taria LLC and APU CoL, respectively. Microwave irradiation at 200°C for 5 minutes was employed as a pretreatment step, followed by hydrolysis using commercial xylanase (Thermomyces lanuginosus, recombinant Aspergillus oryzae, 2500 BXU/g) at 55°C for 24 hours. The resulting hydrolysate underwent filtration with activated carbon and ethanol precipitation to yield purified XOS. Analytical methods, including FTIR spectroscopy, TLC and HPLC, were used for structural and compositional analysis of the purified oligosaccharides. In vitro tests evaluated the ability of XOS to support the growth of beneficial gut bacteria, including Bifidobacterium spp., Lactobacillus fermentum (ATCC 9338), and Lactobacillus casei (ATCC 344), using XOS-enriched media. Additionally, in vivo studies were conducted on rats to determine the biological effects of XOS on gut microbiota. Results: The results demonstrated that prolonged enzymatic hydrolysis for more than 10 hours, using 0.25 g of xylanase per 100 g of substrate, resulted in optimal yields. XOS purity was measured at 87.6% with an 8.1 g yield from wheat bran and 89% purity with a 7.2 g yield from brewers’ spent grains. Structural analysis confirmed the presence of xylobiose, xylotriose, and xylotetraose, with xylotetraose being the most abundant component in WBP-XOS (47.5%), and xylobiose dominating BGS’s derived XOS (47.8%). Biological effects revealed that wheat bran-derived XOS significantly supported the growth of Bifidobacterium spp. and L. fermentum (ATCC 9338) in a concentration-dependent manner, whereas no significant effect was observed on L. casei (ATCC 344). In vivo studies confirmed that XOS consumption increased populations of Bifidobacterium spp. and Akkermansia muciniphila spp. in gut microbiota (p<0.05). Furthermore, XOS consumption reduced plasma cholesterol, triglycerides, and LDL-C levels while increasing HDL-C levels, demonstrating metabolic benefits. Conclusion This research establishes that XOS with prebiotic activity can be efficiently extracted and purified from food industry by-products using microwave-assisted enzymatic hydrolysis. This approach highlights the potential of utilizing agricultural and industrial waste for producing functional prebiotics, contributing to sustainable practices and offering valuable applications in health and nutrition.

Background: The intestinal microbiota of Mongolians and its composition is of great interest of researchers, a few studies have did in this fields. Maybe Mongolian encompass a uniquely wide range of environmental conditions, ethno geographical cohorts and traditional nomadic lifestyles. Goal: We aimed to determine the amount of gut microbiota, including Lactobacillus and Bifidobacterium in the fecal samples of relative healthy Mongolian adults residing in various regions of Mongolia by conventional culture method and PCR. Material and Methods: The study was performed population based cross sectional study in healthy volunteers. In this study, 256 relative healthy Mongolian adults with no history of gastrointestinal associated diseases were enrolled between July 2018 and April 2019. Each participants was asked to complete a questionnaire containing 164 questions about demographics, physical activity, dietary habits. Fecal samples were collected for Lactobacillus and Bifidobacterium analysis using culture method and determination of genus of Bifidobacterium sрp and Lactobacillus spp by PCR. ResultsParticipants had a mean age of 38.9±12.8 years. The mean values of Lactobacillus by culture method were 5.9±1.28 and 6.24±0.94 log10 CFU/ml (4.67х106 , 4.66х106 CFU/ml), respectively. The abundance of Lactobacillus had a positive correlation with grams for fiber and amount of bifidobacterium ((r= 0.495, р<0.001, r=0.288, p<0.05), respectively). Significant difference were observed between groups of milk frequency per day for amounts of lactobacillus. In adult intestinal tracts, B.Bifidum was the most common taxon 31 (29%) followed by B. angulatum 14 (13.1%), B. adolescentis 10 (9.3%), B. catenulatum group 10 (9.3%), B. longum 9 (8.4%). B. lactis, B. breve, B. dentium and B. gallicum were subdominant species. Conclusion: The mean amount of Bifidobacterium and Lactobacillus of all participants were 6.24±0.94 and 5.9±1.28 log10 CFU/ml (4.66*106 , 4.67*106 CFU/ml) respectively. The Lactobacillus abundance of healthy adults was higher in region of Khangai, East and West of Mongolian than other regions. The composition of lactobacillus altered with ageing. Significant correlations were found between fiber, fats, potato and amount of Lactobacillus. Keywords: Bifidobacterium, Colony forming unit, Gut microbiota, Lactobacillus