Traditional national fermented products and cheeses are a source for the search for species and strains of lactic acid bacteria (LAB) which are not within the range of bacterial agents used in the dairy industry. Classical and modern genetic-molecular methods are used to identify LAB isolated from such products. The purpose of our work was isolation and identification of LAB from traditional Carpathian cheeses made from ewe's milk and the study of their technological properties. Three samples of cheese were selected for our research – one sample of brine cheese bryndza and one sample of budz (bryndza before salting), produced in the highlands of the Carpathians and one sample of buts, produced in the foothills zone. 106 cultures were isolated from the samples of cheese. Genus and species identification was completed using classical microbiological and molecular genetics methods. Based on the complex of tinctorial, cultural, physiological and biochemical indices, the LAB isolated were assigned to the following genera and species: Lactococcus spp. (26 cultures), including L. lactis (13 cultures) and L. garvieae (13 cultures); Lactobacillus spp. – L. plantarum (31 cultures); Enterococcus spp. – E. faecium (25 cultures); Leuconostoc spp. – L. mesenteroides (24 cultures). These results were confirmed by molecular genetics methods. The largest range of species was found in a sample of bryndza from the Carpathian highlands. The isolated cultures were studied according to technological properties – milk-coagulation activity, acid-forming ability and resistance to different concentrations of kitchen salt. Most strains of L. lactis ssp. lactis, L. plantarum and L. mesenteroides were active acid-forming agents and coagulated milk in 3–9 hours, while L. garvieae and E. faecium coagulated milk after more than 24 hours. More than 80% of cultures showed resistance to 4% of kitchen salt solution, E. faecium was observed to have the highest salt tolerance. The results of RAPD typing showed significant intra-species heterogeneity, which indicates the need for further research on identification of individual strains. In all samples of cheese, L. lactis, L. garvieae, E. faecium were detected, which shows that they are typical representatives within the traditional Carpathian bryndza. Particular attention was paid to E. faecium, as many researchers have indicated probiotic properties of individual strains, as well as the ability to synthesize volatile substances that enrich the flavor bouquet of cheeses. Today strains of E. faecium are involved in the bacterial composition of starter cultures for cheeses.
The article gives the results of the research on the influence of a developed complex liposomal preparation on the dynamics of morphological and biochemical indicators of the blood of rats subjected to modeled oxidative stress caused by intermuscular injection of 50% carbon tetrachloride at a dose of 0.25 ml per 100 g of body mass. We found that in conditions of intoxication by carbon tetrachloride, the physiological level of hematological indicators of the researched animals’ body was disrupted. This is indicated by the reduction in the amount of erythrocytes, hemoglobin content, concentration of hemoglobin per erythrocyte, increase in the amount of leucocytes, mass of hemoglobin per erythrocyte and increase of colour indicator. Also, we detected suppression of protein synthesis function of the liver. The levels of total protein and albumin fraction were below the normal physiological level. High indicators were observed in the levels of creatinine, urea and total bilirubin. In order to normalize the functional state of the liver under oxidative stress it is reasonable to use a liposomal preparation which contains butafosfan, interferon, thistle and vitamins. In order to normalize morphological and biochemical indicators of the blood of rats subject to intoxication of carbon tetrachloride it is reasonable to use a liposomal preparation that contains butafosfan, selenium, thistle, methionine and vitamins. Using the liposomal preparation Butaselmevit for rats under oxidative stress the morphological and biochemical indicators in the blood normalized. On the 14th day the indictors of the number of erythrocytes, the hemoglobin content, the white blood cell count and red blood indexes compared to control came within the physiological indicators, indicating a recovery of hematopoietic function of the bone marrow and normalized indicators of the functional state of the liver.
Abstract. In the article a comparative analysis of the use of the bacterial preparation Herobacterin and the starter RSF-742 (Chr. Hansen, Denmark) in the technology of brine cheese was conducted. Herobacterin is a bacterial preparation created using bacteria Lactococcus lactis, Lactobacillus plantarum, Enterococcus faecium, Leuconostoc mesenteroides and Lactococcus garvieae, isolated from traditional Carpathian brine cheese brynza and identified using classical microbiological and modern molecular genetic methods (RAPD-PCR, RFLP-PCR, sequencing of the 16S rRNA gene). Анотація. Показано результати порівняльного аналізу використання створеного бакконцентрату Геробактерин із бактеріальним препаратом RSF-742 (Chr. Hansen, Данія) у технології розсільного сиру бринза. Геробактерин − бак-теріальний препарат, створений на міжвидовій, багатоштамовій основі з використанням бактерій Lactococcus lactis, Lactobacillus plantarum, Enterococcus faecium, Leuconostoc mesenteroides і Lactococcus garvieae, виділених із традицій-ної карпатської бринзи та ідентифікованих із використанням класичних мікробіологічних і сучасних молекулярно-генетичних методів (RAPD-PCR, RFLP-PCR, секвенування гену 16S рРНК). Наведено результати досліджень органо-лептичних, фізико-хімічних, синеретичних та мікробіологічних показників сиру бринза із використанням бакконцент-рату Геробактерин у порівнянні із препаратом прямого внесення RSF-742, до складу якого входять такі культури: Lactococcus lactis subsp. сremoris, Lactococcus lactis subsp. lactis, Streptococcus thermophilus, Lactobacillus helveticus. Використання препарату Геробактерин здійснює позитивний вплив на органолептичні, фізико-хімічні та мікробіоло-гічні показники бринзи, усі параметри відповідали вимогам ДСТУ 7065:2009. Рівень виживання молочнокислих бак-терій у бринзі протягом визрівання і зберігання є високим, що підтверджує правильність відбору штамів до бакконце-нтрату Геробактерин, які продемонстрували добру пристосованість до складу і властивостей овечого молока.Ключові слова: бринза, технологія, бакконцентрат Геробактерин, препарат мікробіальний RSF-742, органоле-птичні показники, фізико-хімічні показники, кількість життєздатних клітин.
A promising area for improving probiotics is the search for new sources of strains and the development of complex preparations which would include different types of bacterial cultures that complement each other. Sources of selection may be traditional dairy products, in particular, cheeses made from raw milk. Wild strains can be endowed with antibacterial properties. The antagonistic action of lactic acid bacteria (LAB) has long attracted the attention of researchers and scientists. The aim of the study was to investigate the antagonistic activity against pathogenic and opportunistic microorganisms of LAB strains isolated from traditional Carpathian cheese. Three samples of cheese were selected for the research – one sample of brynza and budz (brynza before salting), made in the highlands of the Carpathians, and one sample of budz, made in the foothills. LAB were identified using classic microbiological and modern molecular genetic methods (RAPD-PCR, RFLP-PCR, 16S rRNA gene sequencing). The objects of our studies were five strains of LAB: Lactococcus lactis IMAU32258, L. garvieae JB2826472, Enterococcus durans FMA8, E. faecium L3-23, E. faecium IMAU9421. Technological parameters such as acid-forming activity of milk fermentation, resistance to high concentrations of NaCl and temperature optimums of cultivation were taken as the main criteria for assessing the suitability of LAB for inclusion in fermentation preparations. Antagonistic activity was determined by agar diffusion (agar well method) and optic density of test cultures using a Multiscan FC microplate reader (Thermo scientifiс, USA) at the wave of 620 nm. There were four reference strains of pathogenic and opportunistic microorganisms were test cultures: Listeria monocytogenes PCM 2191, Staphylococcus aureus PCM 458, Escherichia coli PCM 2208, Salmonella typhimurium PCM 2182. Strains of the test cultures were received from the collection of microorganisms of the Institute of Biology and Biotechnology the (University of Rzeszów, Poland). According to the ability of LAB strains to form lactic acid, L. lactis IMAU32258 was the best acid-forming agent with an acid-forming energy of 94 °T. E. faecium was characterized by moderate levels of active and titratable acidity. Less pronounced acid-forming ability was determined for the species E. durans and L. garvieae. Cultures of the genus E. faecium, L. garvieae and E. durans were the most resistant to high concentrations of NaCl (6.5%). Regarding temperature optimums, we found that strains of E. faecium and E. durans species grew both at temperatures of 10, 15 and 45 °C, whereas no growth of L. lactis IMAU32258 and L. garvieae JB282647 2 was observed at 45 °C. Among the studied bacteria, the strains of E. durans FMA8 and E. faecium L3-23 were characterized by the highest antagonistic activity in producing the largest zones of growth inhibition and optic density of pathogenic and opportunistic microorganisms. The strain L. garvieae JB282647 2 exhibited the lowest level of antagonistic activity against pathogenic and opportunistic microorganisms.
The aim of the work was the study of keeping probiotic properties of sour-milk butter with inclusion of Lactobacillus acidophilus La-5 (La-5) monoculture. Flora Danica mesophile culture independently (FD); in combination with La-5 and La-5 independently were used for fermenting cream. The output consistence of culture in cream was 1×106 CFU/cm3. In autumn-winter and spring-summer period of the year four butter groups were prepared, they differed by temperature of cream fermentation: I group – (30±1) ºС; II – (37±1) ºС; III – stage regimes of combination of fermentation and physical maturing; IV group – introduction of cultures into oil kernel; the output concentration – 1·108 CFU/cm3. As to the features of summer and winter periods, in summer one cream fermentation is more active that is indicated by more number of cells of both microbial cultures. The best parameters of viable cells keeping were typical to the samples at FD+La-5 use and temperature of cream fermentation (30±1) ºС. Storage life of sour-cream butter with probiotic properties is 35 days at temperature 0…-5 ºС.
Bacterial resistance to antimicrobials is a global health problem that affects not only on humane and veterinary medicine, but also on food products. The food chain can be by transmission of antibiotic resistance from bacterial populations to animals and humans. Literary data on the current state of the problem of antibiotic resistance of lactic acid bacteria (LAB) in Ukraine and in the world are given in the review. Possible ways of transferring resistance to antibiotics through fermented dairy products are shown. The main aspects of the danger of transmission of antibiotic resistance genes through the LAB and fermented dairy products are revealed. The main modern approaches to the definition of antibiotic resistance of microorganisms with the use of classical and modern research methods are described. The article provides the main sources of information on the safety of use of LAB as starter cultures and probiotics for the production of fermented dairy products. The hypothesis of the resistance gene's reservoir suggests that LAB can be a reservoir of sustainability genes, and the subsequent transfer of such genes to pathogenic and opportunistic microorganisms. The presence of antibiotic resistance genes transposed horizontally is inadmissible for lactobacilli, which are used as commercial bacterial agents for the production of fermented dairy products. According to the literature data, the absence of acquired antimicrobial resistance has become an important criterion for assessing the safety of lactobacilli, which are used as starting cultures for the production of fermented dairy products or probiotics. It has been established that it is obligatory to study the antibiotic resistance gene in addition to clinical and laboratory methods of studying the antibiotic resistance of LAB. To minimize the formation of antibiotic-resistant bacteria in food products of plant and animal origin it is possible by careful monitoring of residues of antibiotics in raw materials and finished products. This will prevent the entry of antibiotic resistant strains into the natural cycle.
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