Growth Of Test Cultures Research Articles

ОЦЕНКА БЕЗОПАСНОСТИ ПРИМЕНЕНИЯ ПОЛИМЕРНОГО МАТЕРИАЛА «ПЕНОПЛЕКС» В ЖИВОТНОВОДСТВЕ

The article presents data on veterinary and sanitary and hygienic assessment of the polymer material «Penoplex». The above material is made of Styrofoam and used in many areas of production, including to reduce heat loss of livestock facilities. Cattle and pig manure was used as a contact medium with the material under study. The duration of contact with the material (exposure) was 30 days. To study the resistance of the material to disinfectants, we used: 10 % sodium hydroxide solution (80 °C); 5 % solution of soda ash (70 °C); clarified solution of bleach containing 3 % active chlorine; 40 % solution of formaldehyde; 2 % solution of hydrogen peroxide. Studies of samples of the polymer material «Penoplex» for resistance to animal secretions and disinfectants have shown that the polymer material is resistant to them. During the experiment and after its completion, the «Penoplex» material had no visually visible changes on the outer layer. The used disinfectants and the model environment did not violate the structure of the polymer material «Penoplex». A slight change in the color of the «Penoplex» was found on the 20th day of exposure to 10 % solution of sodium hydroxide with temperature of 70 °C. For sanitary and bacteriological evaluation of «Penoplex», the disk method was used. Discs with a diameter of 10 mm were prepared from the material under study; wood discs were used as a control. Studies have found that Penoplex has no effect on sanitary-indicative microorganisms and is neutral in relation to their growth, which indicates the absence of release of substances from it into the environment that can delay or stimulate the growth of test cultures. The veterinary and sanitary and hygienic assessment of the polymer material «Penoplex» is the basis to recommend it for use in the construction of livestock buildings and inclusion as an addition to the current «List of polymer materials and structures permitted for use in the construction and technological equipment of livestock facilities» in the prescribed manner.

Determination of the antibacterial activity of flavonoids from callus Scutellaria galericulata L. for the development of a functional curd product

The antimicrobial effect of extracts from callus of the common skullcap with the prospect of using in the recipe of a functional curd product for therapeutic and preventive action is studied. It is known that plants of the genus skullcap contain phenolic compounds that cause antimicrobial action, the most common among them are flavonoids-baykalin, scutellarein, hydrolyzed to glucuronic acid and aglycones-baykalein and scutellarein, vogonin, etc. the Study of antimicrobial activity was carried out in accordance with the requirements of The state Pharmacopoeia XI edition. Antimicrobial activity was determined in relation to 15 test cultures by diffusion in agar. The method is based on the assessment of inhibition of growth of test cultures of microorganisms by certain concentrations of the test object. Rod-shaped bacteria (Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, Serracia marcescens, Escherichia coli, Morganella morganii, Hafnia alvei, Bacillus cereus), coccus microflora (Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecium), different strains of fungi of the genus Candida (Candida non-albicans № 136, 138, 142, 144). The result was evaluated according to the following criteria: “-“ – growth of the test culture (there is no antibacterial effect); “+” – no growth (the antibacterial effect is pronounced); “±” – inhibition of growth (bacteriostatic action).

Determining potential probiotic properties of human originated Lactobacillus plantarum strains

In this study, twenty Lactobacillus plantarum strains which were isolated from the fecal samples of humans were investigated in vitro for their characteristics as potential new probiotic strains. The L. plantarum strains were examined for resistance to gastric acidity in simulated gastric juice at pH 2.0, 2.5, 3.0, and 3.5. The growth of test cultures with different pH was monitored after 0, 10, 30, 60, 90, and 120 min of incubation using a spectrophotometer at 550 nm. At the same time, samples were serially diluted in sterile PBS, and counts of viable bacteria were determined by plate counts using MRS agar for each pH and time parameter. The strains were also examined for resistance to 0.4% phenol, production of H2O2, adhesion to Caco-2 cell line and antimicrobial activity. It was determined that the artificial gastric juice, even at pH 2.0, did not significantly change the viability of the cultures. Except L. plantarum AA1-2, all strains were detected at 8 ∼ 9 log10 CFU/g. It was found that all L. plantarum strains showed good resistance to 0.4% phenol, and only one strain (AC18-82) produced H2O2. Good adhesion of L. plantarum strains to Caco-2 cells was observed in this experiment. These selected strains also showed antimicrobial activity.

VITAMIN ANALYSIS BY MICROBIAL AND PROTOZOAN ORGANISMS: RESPONSE TO FOOD PRESERVATIVES AND NEUTRALIZATION SALTS

ABSTRACTVitamin analyses using protozoa (Tetrahymena pyriformis, Ochromonas danica and Ochromonas malhamensis) as test organisms were found to he affected by lower concentrations of neutralization salts than were the vitamin analyses which used bacteria and yeast as test organisms. Neutralization salts are formed during vitamin extraction procedures. Growth of protozoa and yeast was affected by the food preservatives‐sodium sorbate, sodium propionate and sodium benzoate. Except for sodium benzoate inhibition of Lactobacillus leichmannii, the growth of bacterial test cultures was not affected by these chemicals. Levels of the neutralization salts and food preservatives in vitamin assays that are required to affect the growth of the test organisms were calculated. These levels were compared to the concentrations of salts formed by accepted vitamin extraction procedures to determine the dilutions of sample extracts necessary to avoid interference. Similar calculations were completed to determine minimal dilutions of foods necessary to avoid the effects of food preservatives on the test organisms. Acids and bases that neutralized to form salts that had the least effect on the growth of the test cultures were determined.