Lactic Acid Bacteria as A Bio Preservative: Importance and Production

Biopreservation is the method of employing natural microflora and their antimicrobial compounds to extend the storage life and improve the safety of foods. Streptococcus lactis was the first pure strain of lactic acid bacteria which was isolated from milk by Liszt. He named it bacterium lactis. Lactic acid bacteria are gram-positive, acid-tolerant, have low Guanine-Cytosine content and are generally non-sporulating, non-respiring, either spherical cocci or rod-shaped bacilli bacteria that share most of them their metabolic and physiological characteristics. These bacteria are mostly present in decomposing plants and milk products. They have an increased tolerance to acidity. Most species are incapable of respiration and therefore media used for lactic acid bacteria include a carbohydrate source. At the end of carbohydrate fermentation, these bacteria give out lactic acid as a major end product. The review focuses on the process of lactic acid production by lactic acid bacteria and its expanding importance in a variety of disciplines. Keywords: Lactic acid bacteria, bio preservative, food, microflora

Behaviour of Listeria monocytogenes and Natural Microflora during the Manufacture of Riojano Chorizo (Spanish Dry Cured Sausage)

Riojano chorizo is a dry cured sausage manufactured with traditional technologies without adding starter cultures at low temperatures. Its characteristics differ from other types of chorizo since sugars and nitrites are no added and processing temperatures are low- This work evaluates the behaviour of Listeria monocytogenes during the processing of inoculated Riojano chorizo as well as the natural microflora that can play a technological role or be of interest as indicators. The sausage mixture was inoculated with a cocktail of three selected strains of L. monocytogenes (CECT 932, CECT 934 and CECT 4032) (4 log10 CFU/g) and after processed following the traditional production method. Samples were taken before inoculation, after inoculation, after stuffing (day 0) and on days 6, 13, 21 and 28 of processing. L. monocytogenes, mesophiles, Micrococcaceae, lactic acid bacteria, Enterobacteriaceae, S. aureus, sulfite-reducing clostridia and molds and yeast counts were evaluated. Furthermore, pH, water activity and humidity were determined. No growth of L mocytogenes was observed during the first 6 days, when the temperature of processing was 4 °C. The low temperature in the initial stages was a relevant hurdle to control L. monocytoegenes growth. A significant decrease (p ≤ 0.05) in L. monocytogenes counts was observed on day 13 compared to the initial counts. During drying (days 6 to 21) a reduction in this pathogen of 1.28 log CFU/g was observed. The low water activity below 0.92 on day 13 and 0.86 on day 21 seems to be critical for the reduction of L. monocytogenes.

Treatment Method of the Soil, Polluted by Oil and Oil Products in Climatic Conditions of Azerbaijan

In this work, two biotechnological technologies were tested to restore contaminated soils using microorganisms. One technology with the activation of natural microflora and a technology that requires the introduction of oil-oxidizing microorganisms in the form of a biological product. When using biological methods of cleaning soil from oil pollution in combination with agrotechnical methods, the natural microflora of oil-polluted soils was activated. The introduction of a biological product under these conditions makes it possible to increase the intensity of soil cleaning from oil pollution as a result of the cleaning time in comparison with the natural microflora, it can be reduced by 3–4 months. It should be noted that the methods of cleaning oil-contaminated soils using microorganisms in arid soil-climatic conditions are most effective in the spring and until mid-summer. In the summer, due to high temperatures, the activity of microorganisms decreases. Microorganisms become active again in the autumn. During this period, the activity of microorganisms is higher than in the spring period and this is due to the fact that before the summer period the number of microorganisms increases and after a slight decrease in activity, intensive biodegradation of oil pollution continues again.

Enumeration of Microflora from Ingredients and Idli Batter

Background: Microorganisms are responsible for characteristic changes in the fermented foods. They result in the sequential changes during fermentation of food, resulting in souring, leavening and changes in flavour, body and texture. The present study was aimed to enumerate the natural microflora present in raw ingredients used as well in fresh and fermented idli batter. Methods: Study was conducted during the period 2019-2020 to develop solid state fermented cultures for whey based idli batter at Department of Dairy Microbiology, Dairy Science College, Bangalore. The raw ingredients used for idli preparation were sourced from local market of Bangalore. Lactic counts such as leuconostoc, enterococci, pediococci and lactobacilli, as well as yeast counts were enumerated using different selective media by pour plate method. Result: The leuconostoc count of rice rava, black gram dhal and fresh idli batter on sucrose agar ranged from 2.0 to 3.78 log10 cfu/g; Lactobacilli count on MRS agar varied from 2.0 to 4.11 log10 cfu/g. Yeast count on potato dextrose agar ranged from 1.6 to 2.3 log10 cfu/g. Lactic counts (includes leuconostoc, lactobacillus, pediococci, enterococci) in fresh idli batter ranged from 3.63 log10 cfu/g to 4.77 log10 cfu/g, whereas in fermented idli batter varied from 2.56 log10 cfu/g to 8.74 log10 cfu/g. The yeast counts in fermented batter ranged from 9.23 to 9.56 log10 cfu/g.

DETERMINATION OF THE SAFETY OF IRRADIATED PRODUCTS BY THE CONTENT OF QUINONES

The result of research, conducted using our immuno-chemical testing system (Reaction of Indirect Hemaglutination) shows that application of radiation exposure to farming and agro products in dosages needed for prolongation of their storage lifetime, for prevention of rotting and germination or for decontamination of feed-stuff from natural microflora and insects; leads to increase in radiotoxins contents thereof with maximums reached on 7-15 days. Besides, traces of radiotoxins in reaction of indirect hemaglutination depend on type of product, radiation dosage and time of product storage after radiation treatment.

Effect of applying crust-freezing after skin-packaging on the natural microflora of Atlantic salmon (Salmo salar) during storage at low temperatures

The aim of the present study was to evaluate the effect of crust-freezing (CF) on fresh salmon fillets in skin-packaging during storage at −2.0°C. After CF, all treated samples and untreated controls were stored in a refrigerated cabinet for 20 d. Sampling was carried out at days 0, 2, 6, 8, 10, 14 and 20 in order to analyse total volatile basic nitrogen (TVB-N) and levels of mesophilic and psychrophilic viable counts (MVC and PVC). Enterobacteriaceae (ENT), lactic acid bacteria (LAB), H2S-producing bacteria (SPB) and Pseudomonas spp. (PSE). No significant differences in TVB-N were found between samples except for those taken on day 20 where TVB-N levels of CF samples were lower than controls. Our results suggest that ENT might be the limiting microbial group to determine the end of shelf-life. Thus, if this group is used as an indicator of acceptability, the shelf-life of salmon can be extended from 8 to 20 d when skin-packed and then treated with CF.

INFLUENCE OF PROFORT FEED ADDITIVE ON MEAT PRODUCTIVITY OF TURKEY OF «HYBRID CONVERTER» CROSS

An acute problem in industrial turkey breeding is maintaining a high immune status of birds in order to increase the safety of the stock, productivity and, accordingly, the quality of meat. At the same time, the most important factor is proper bird feeding arrangement. In recent years, there has been a tendency in industrial turkey feeding to use various products that improve the birds’ digestion physiology which can replace feed antibiotics. The search for biologically active substances that can stimulate development of the natural microflora of turkeys in order to suppress pathogenic bacteria by increasing the number of bifido and lactoflora are of great interest in science and practice. Various probiotic products have similar properties. The aim of our research was to study the effect of Profort probiotic feed additive on meat productivity of turkeys of Hybrid Converter cross. A production experiment was carried out on turkeys of Hybrid Converter cross. Control slaughter of turkeys was carried out at the age of 98 days. Ten birds were selected from each group. The birds were fed for 60 days, the eed additive was given at a dose of 1 kg per 1 ton of the combined feed. Poultry processing and anatomical and morphological analysis of the carcasses were carried out in the laboratory of the research center of the Federal State Budgetary Scientific Institution “All-Russian Research Veterinary Institute of Pathology, Pharmacology and Therapy”. The results were statistically processed using Statistica v6 program . Studies showed that application of Profort feed additive had a positive effect on meat production of turkeys. The superiority of the experimental group was clearly expressed in all the studied parametres. The results obtained allow us to recommend Profort probiotic feed additive for use in turkey breeding in order to increase productivity