Spontaneous Microflora Research Articles

Justification and microbiota compositions development for the fermentation of raw meat

In the production of fermented meat products, microorganisms of various taxonomic groups play an extremely important role, namely in the formation of specific taste, aroma, colour, and consistency. Both fermentative and spontaneous microflora take part in the components' transformation of meat raw materials during the maturation of such products, and the course of this process depends on the metabolic activity of the strains. In accordance, this article's purpose is to select microbiota compositions (lactic acid bacteria and coagulase-negative cocci) for the fermentation of meat raw materials. So, as a result of the research, 4 compositions were selected, two of which are lactic acid bacteria with micrococci (No. 2, 3) and two lactic acid bacteria with staphylococci (No. 1, 6). They were characterized by the high productivity of each of the components of the leavening composition, in particular, it was established that the number of MKB increased – by 4.3-6.5 times, and micrococci and staphylococci – by 7.7-28.6 times, respectively. For these compositions, mutual stimulation of the components was observed, contributing to the active microorganisms' development and their biochemical activity. Fermentation compositions No. 1, 6, 4, and 6 had the highest nitrite-reducing activity, and a high level of proteolysis characterized compositions No. 1, 2, 3, and 4. According to the results of determining the antagonistic activity against opportunistic and pathogenic microorganisms, it was established that the investigated compositions exhibit antagonistic activity against both gram-negative and gram-positive microorganisms.

Textile fibers resistant to biodestruction is a way to improve indoor ecological conditions

The aim of research was to observe and to describe biodestructions of fabrics that usually used inside a home, to estimate the destruction (total number of destruction “N” and destruction index “K”). The samples of fabrics were placed into a thermostat in sterile Petri dishes on moistened sterile filter paper in order to stimulate the microflora occurred on fibers. Incubation carried out in a thermostat at a +24-28 °C, humidity of 90-100% and exposed for 8 month. The samples examined with a microscope. As a result of the study of fiber’s damage, the types of damage were identified as follow: layering, fretting, mottling, fouling, spotting, swelling, granular disintegration, delamination, thinning, and damage of the fiber wall. Initially the most destructed was detected sample of natural silk and hemp according to the highest value of destruction index K. However, after 8 months of exposure, this sample turned out to be the most resistant to biodegradation. The data obtained based on the evaluation of the biostability of fabrics made from various textile fibers showed that the usage of natural silk, hemp and polyester able to supply textile with resistance to biodegradation by spontaneous microflora.

AN INFLUENCE OF SPONTANEOUS MICROFLORA OF FERMENTED HORSEMEAT PRODUCTS ON THE FORMATION OF BIOLOGICALLY ACTIVE PEPTIDES

At present, different methods are used to accumulate functional peptides in meat raw materials, including the use of spontaneous microflora during autolysis, the use of the microbial enzymes (the application of starter cultures) and the use of the non-microbial enzymes (enzymes of animals and plant origin). Each method has its own specific characteristics of an impact on raw materials, which requires their detail study. This paper examines an effect of spontaneous microflora of fermented meat products from horsemeat on formation of biologically active peptides. Using the T-RFLP analysis, it was established that in air dried and uncooked smoked sausages produced with the use of the muscle tissue of horsemeat as a raw material, a significant proportion of microflora was presented by lactic acid microorganisms. The highest content of lactic acid microflora was observed in sample 1 (52.45 %), and the least in sample 3 (29.62 %). Sample 2 had the medium percent content of microflora compared to samples 1 and 3 — 38.82 %. It is necessary to note that about 25 % of microflora was unculturable; i.e., it had metabolic processes but did not grow on culture media. In the samples, the representatives of Actinobacteria and Pseudomonadales were found. Pathogenic and conditionally pathogenic microflora was not detected. Not only quantitative but also qualitative changes were observed in the studied samples. For example, in samples 1 and 2, the fractions of amilo-1,6-glucosidase, fast-type muscle myosin-binding-protein C; glucose-6-phosphate isomerase; fast skeletal muscle troponin I, phosphoglycerate kinase, pyruvate kinase and skeletal muscle actin were found, which were absent or reduced in sample 3. Therefore, in the studied product, good preservation of the main spectra of muscle proteins was observed, and the identified fractions, apparently, can be sources of new functional peptides. Not only quantitative but also qualitative changes were observed in the studied samples. For example, in samples 1 and 2, the C-terminal fragments of the myosin heavy chain were found, which were absent in sample 3. Also, the significant content of myoglobin was revealed in samples 2 and 3, and the myosin light chain was found in sample 1. Therefore, in the studied product, good preservation of muscle proteins myosin and myoglobin, which can be a source of new functional peptides, was observed. Based on the results of tandem mass-spectrometry, the proteins and natural short peptides present in the analyzed extracts were identified by the obtained masses. They belonged mainly to different peptides of equine myoglobin. Also, we identified several fragments, among which fast skeletal muscle troponin T and muscle creatine kinase were found. The obtained materials can be regarded as an experimental basis for the directed impact of starter cultures with a possibility to predict the protein and peptide composition of a finished product including with the aim of obtaining biologically active peptides.

ВПЛИВ АВТОХТОННИХ ДРІЖДЖІВ НА ВМІСТ ФЕНОЛЬНИХ СПОЛУК У ЧЕРВОНИХ СТОЛОВИХ ВИНОМАТЕРІАЛАХ

Actuality of the research. Scientists of the world viticultural countries paid much attention to the study of autochthonous strains of wine yeast and the mechanism of yeast influence onto wine phenolic composition. There are now such researches in Ukraine, in spite of the attention to the quality of local wines. Thus, the autochthonous strains of wine yeast researches in Ukraine are very important.Target setting. The color of the wine is determined by phenolic compounds and melanoidins. Flavones - flavonols (yellow), anthocyanins (different shades of blue and purple); leykoantotsiany are phenolic compounds that give color to wines. Technology of red wines aimed at the extraction of required quantity of the structural elements of grape clusters. The strains of wine yeast is influencing the processes of extraction, so it is necessary to examine the extent to which they are able to influence these processes in relation to phenol and coloring substances.Actual scientific researches and issues analysis In this article, we studied the mechanism of interaction of phenolic complex of grapes and wine with yeast. The implication of wine yeast in red wine colour is twofold. On one hand, wine yeast influences the extraction of grape anthocyanins during maceration and fermentation, depending on their alcohol production capacity. They also influence the formation of more stable anthocyanin forms during maturation and ageing. On the other hand, yeast can promote anthocyanin degradation and participate in certain interactions with pigments that result in colour loss.The research objective Therefore, the aim of the study was to determine the peculiarities of phenolic composition of wines Cabernet Sauvignon, Odessa zhemchug, Charivnyi, Agate taroskyi, Otrada, obtained under microvinification with the use of autochthonous strains of wine yeast.The statement of basic materials. 30 samples of wines obtained by fermentation on spontaneous microflora and on 5 strains of indigenous yeast Y-3645; Y-3648; Y-3647; Y-3649; Y-3646 were chemically analysed. Its phenolic composition were evaluated and the yeast strain, the use of which provides better extraction of phenolic compounds and coloring was determined.Conclusions. The optimum fermentation conditions were found. The fact, that the yeast strain Y-3647 provides better extraction of phenolic compounds and coloring was determined.

Comparing Different Schemes of Agricultural Wastewater Lagooning: Depuration Performance and Microbiological Characteristics

Since the number of factors influencing depuration efficiency and energy requirement is high, the choice of the most suitable aeration scheme in aerated lagooning systems treating agricultural wastewater is a difficult task. This study provides technicians and researchers with guidelines on air diffuser position, presence of inoculum and characteristics of microbial mass, focusing organic matter degradation and energy performance of aerated ponds treating citrus processing wastewater. Four experimental batch tanks were set up: three tanks were subject to low air flow rates and times, while a fourth tank was not aerated. The organic matter degradation in the aerated tanks was on average six times higher compared to the non-aerated tank. Positioning the air diffuser at mid-depth and consequent separation of tank contents into two layers determined a decrease in the depuration performance, presumably due to the reduced transfer of oxygen to wastewater. Although the ability of spontaneous microflora to adapt to essential oil concentrations up to 1400 mL L−1 was detected, the effect of inoculum (50% of wastewater with spontaneous microflora already adapted to high essential oil concentration) was not noticeable. Overall, the results of the investigation confirm the suitability of aerated lagoons subject to fine bubble aeration also for agricultural wastewater depuration.

Fatty-acid alkyl esters in table olives in relation to abnormal fermentation and poorly conducted technological treatments

There are several methods to prepare table olives, and each of the steps and conditions during this processing can affect the composition and nutritional value of the product. The influence of abnormal fermentation and poorly conducted technological treatments was examined here in terms of the lipid fraction of table olives. In ‘Greek style’ olives, a low concentration of brine can allow the growth of spontaneous microflora and consequent organoleptic defects (‘putrid/butyric fermentation’, ‘winey-vinegary’). Here, the ‘Kalamata’ and ‘Moresca’ cultivars can produce methyl esters (methyl oleate/ linoleate: 553 and 450 mg·kg -1 oil, respectively) and ethyl esters (ethyl oleate/ inoleate: 4764 and 4195; palmitate: 617 and 886 mg·kg -1 oil, respectively). In ‘Sevillan style’ olives, a high NaOH concentration influences the fatty-acid composition less, but is difficult to eliminate, for a ‘soapy’ defect. The ‘Giarraffa’ and ‘Nocellara del Belice’ cultivars produce only ethyl esters (ethyl oleate/ linoleate: 222 and 289 mg·kg -1 oil, respectively). With this production of ethyl and methyl esters from the principal fatty acids in the lipid fractions of table olives, methods that provide only biological treatments (i.e., Greek style) pose more risk than methods that provide only chemical treatments (i.e., Sevillan style).

The Role of Spontaneous and Augmented Microflora in Cleaning Oil-Contaminated Loamy Gray Soils of Southern Kazakhstan

Kazakhstan is one of the major oil producing and processing countries. Unfortunately, along with the growing volume of processed crude oil intensifies the problem of environmental pollution. In this context, the aim of this work was to study the role of microorganisms in the bioremediation of oil-contaminated loamy gray soils of South Kazakhstan. The studies were allocated 2 active strains of microorganisms Micrococcus luteus IS16 and Micrococcus varians IS41, which in vitro degraded 99.3% contributed by 2.0% kumkol oil. In real soil and climatic conditions of spontaneous microflora reduced content Kumkol oil by 39.6%, augmented microorganisms degraded 57.3% of oil, 92.8% of diesel fuel for 2 months. DOI: 10.5901/mjss.2015.v6n1s2p103

Indigenous Starter Cultures to Improve Quality of Artisanal Dry Fermented Sausages from Chaco (Argentina).

Lactic acid bacteria (LAB) and coagulase negative cocci (CNC) were isolated from artisanal dry sausages sampled from the northeastern region of Chaco, Argentina. In order to evaluate their performance in situ and considering technological features of the isolated strains, two mixed selected autochthonous starter cultures (SAS) were designed: (i) SAS-1 (Lactobacillus sakei 487 + Staphylococcus vitulinus C2) and (ii) SAS-2 (L. sakei 442 + S. xylosus C8). Cultures were introduced into dry sausage manufacturing process at a local small-scale facility. Microbiological and physicochemical parameters were monitored throughout fermentation and ripening periods, while sensory attributes of the final products were evaluated by a trained panel. Lactic acid bacteria revealed their ability to colonize and adapt properly to the meat matrix, inhibiting the growth of spontaneous microflora and enhancing safety and hygienic profile of the products. Both SAS showed a beneficial effect on lipid oxidation and texture of the final products. Staphylococcus vitulinus C2, from SAS-1, promoted a better redness of the final product. Sensory profile revealed that SAS addition preserved typical sensory attributes. Introduction of these cultures could provide an additional tool to standardize manufacturing processes aiming to enhance safety and quality while keeping typical sensory attributes of regional dry fermented sausages.

Aerated lagooning of agro-industrial wastewater: depuration performance and energy requirements

Intensive depuration plants have often shown low reliability and economic sustainability, when utilised for agro-industrial wastewater treatment, due to the particular wastewater properties: high organic load and essential oil concentrations, acidity, nutrient scarcity and qualitative-quantitative variability of effluents. Aerated lagooning systems represent a suitable alternative, because they are able to assure good reliability and low energy requirements, avoiding the drawbacks shown by the intensive depuration plants. In order to optimize performance of the lagooning systems, particularly in terms of energy requirements, depuration processes of aerobic-anaerobic aerated lagoons were investigated, both at full- and laboratory-scale. Citrus processing wastewater were subject to bubble aeration with low flow rates and limited time; the removal rate of organic load was evaluated and energy requirements of different depuration schemes were compared. The experimental investigations in full-scale aerated lagoons showed a low energy supply (0.21-0.59 kWh per kg of COD (Chemical Oxygen Demand) removed with an average value of 0.45 kWh kgCOD –1), an adequate equalisation capability and constantly good depurative performance also with high concentrations of essential oil (500-1000 ppm). The experimental investigations in lab-scale aerated tanks under controlled conditions indicated the possibility of decreasing energy requirements (down to 0.16 kWh kgCOD –1) by reducing aeration power (down to 0.6 W m–3) and limiting aeration time to night 12 hours only, when energy price is lower. In spite of the low aeration, the COD removal rates were on the average six-fold higher compared to the anaerobic tank. Other outcomes indicated an ability of the spontaneous microflora to adapt to high concentrations of essential oils, which however did not provide an increase of the removal rate of the organic load in the experimented scheme.

Depuration in aerated ponds of citrus processing wastewater with a high concentration of essential oils

Citrus processing wastewater was treated in aerated pilot plants in order to evaluate the following: (a) energy efficiency under different air flow rates and times; and (b) limits of spontaneous microflora in adapting to essential oils. In comparison to permanent air flow, night aeration for 12 hours determined an increase of up to 12% of the monthly removal rate of chemical oxygen demand (COD) and a consequent reduction by 10% of energy consumptions per unit of COD removed from 0.63 to 0.57 kWh/kgCOD. Lowering night aeration from 14 to 7 l/m3/h reduced by only 10% the removal rate of COD; the energy consumption per unit of COD removed (0.32 kWh/kgCOD) was consequently reduced by more than 40%. Dissolved oxygen was maintained at very low level, rarely exceeding 0.2 ppm, with no bad smell. The consequent high oxygen deficit of 98–99% of saturation induced high oxygen transfer efficiency. The microbial population was characterized mainly by aerobic bacteria; only 5–8% of bacteria were strictly anaerobic. In the deep tank layer under the air diffuser a small amount of sludge settled (0.03–0.04 kg of dry matter per kg of COD removed), containing only 3% of total organic matter detected at the end of the depuration process. The fact that the concentration of essential oils could be progressively increased up to 1400 ppm without noticeably slowing down the biological processes demonstrated the remarkable microbial adaptation.

Studies concerning the use of Lactobacillus helveticus and Kluyveromyces marxianus for rye sourdough fermentation

The aim of this study was to investigate the fermentation behaviour, antioxidant activity and rheological behaviour of the sourdoughs prepared with Lactobacillus helveticus and Kluyveromyces marxianus. The final acidity of the sourdough after 18 h of fermentation was higher at higher temperatures (40 °C) and for the formulations with whole rye flour. The highest lactic/acetic acid ratios were obtained in case of more fluid sourdoughs fermented at 40 °C. The antioxidant properties of the sourdoughs are correlated with metabolic activity of the microorganisms, the DPPH radical scavenging activity being higher for optimum conditions of Lactobacillus helveticus growth. On the other hand, the rheological properties of the sourdoughs are not significantly influenced by the temperature. Sourdoughs formulations with whole flour are more viscous, as well as the controls fermented by the spontaneous microflora. The results of the bread-making process simulation by means of Mixolab indicate differences between dough formulations mainly depending on flour type.

Suitability of a probiotic Lactobacillus paracasei strain as a starter culture in olive fermentation and development of the innovative patented product “probiotic table olives”

Probiotic bacteria are generally available for consumers as concentrated preparations or incorporated in milk-based foods. Due to an increased interest of the market for probiotic foods as well as to meet a demand of industry for innovation, a new kind of probiotic food has been developed using table olives as a carrier. Green table olives, produced according to the Spanish-style, are obtained by a fermentation which can be carried out by spontaneous microflora, even if the use of starter cultures is desirable to obtain a more controlled process. In this regard, the selected strain Lactobacillus paracasei IMPC 2.1 of human origin was used in the dual role of starter and probiotic culture, and here we describe the different aspects which have been evaluated and solved to utilize that strain for the development of a new table olive-based probiotic food. These aspects include selection of the strain on the basis of its probiotic properties, molecular characterization, compatibility with the carrier food, and efficacy as starter. The final product meets commercial and functional requirements throughout its shelf-life.

Change in the properties of polyester sewing thread caused by microorganisms

The resistance of polyester sewing thread to spontaneous microflora formed on the surface of the thread during production, storage, and developing in conditions of high humidity was investigated. The change in the breaking strength, abrasion resistance, whiteness, and the overall color difference of the thread induced by microflora is approximated by exponential equations. The kinetics of the change in the electrostatic field surface charge density of the polyester thread is approximated by a linear regression equation. The kinetic curves and their approximation examined in the article can be used to predict the properties of poly(ethylene terephthalate) thread stored or used in conditions of high humidity and exposure to spontaneous microflora.

THE CONDUCT OF SOME SELECTED YEASTS STRAINS UNDER THE INFLUENCE OF SOME EXOGENOUS FACTORS

SUMMARY It is already known the fact that in the spontaneou s fermentation that is produced in the sowing absence with the selection yeasts, the indig ene micro flora assures the fermentation process (2). Although the Saccharomyces cerevisiae species with her grate variety is not dominated on the grape surface, when it grows the a lcohol contain of the fermentation must, the yeasts indigene of Saccharomyces type become predominant and ensures the fermentation ending. In the present study, after th e selection of the present yeast strains in the spontaneous micro flora, the identification and the systematic integration of the isolated (1), we have passed to the second level: the conduct che ck of the strains in different environmental conditions (temperature, sugar concentration, and the SO 2 doses). All the tests have been made in comparison with natural fermentation of grape must, separated for each strain. The strains that belong to the Saccharomyces ellipsoideus strain from the spontaneous micro flora show o good fermentation activity when the fermentation temperature is between 18 and 25°C and the maximum sugar concentration from the environment is under 250g/l. The natural concentration that was made in the same environmental conditions show a higher prefermentation and fermentation period and a lower maximum of sugar metabolic process in comparison with the fermentation inducted in the se lection strains. When the grapes were sulfated as a result of a crop that was stroked wit h mould the natural fermentation is developing very slow, so it is required a use of th e selection yeasts, that prove to be very useful in those conditions.

UTILIZATION OF LOCAL LACTIC ACID BACTERIA STRAINS FOR PRODUCTION OF CHEESE WITH USING THE SOY ALBUMEN

On the base of the lactic acid bacteria strains isolated from spontaneous microflora (local sour milk products) two variants of the leaven. With adding Lactococcus lactis ssp. lactis biovar diacetylactis for improvement of the taste and odour of the combined cheese received on the base of milk and soya albumen were created. Lyofhylized leaven with 10 % Lactococcus lactis ssp. lactis biovar diacetylactis was completely up to the quality, requirements at production of standard cheese (on cow milk) with low temperature of the second heating.

Microflora of the Respiratory Surface of Rodents Exposed to "Inert" Particulates

To test the possible favoring effect of inhaled inert dust on the spontaneous microflora of respiratory surfaces of rodents, groups of mice, hamsters, and rats were exposed to graphite (1 mg/cu m) and calcium sulfate (1 mg/cu m) for 12 hours daily, for periods up to four months. A limited number of hamsters have been exposed to high concentrations of graphite dust (10 mg/cu m) continuously (23 hr/day) up to 32 consecutive days. In general, particulate aerosols do not appear to enhance colonization of bacteria or stem bronchi and air spaces. However, a fraction of the hamsters exposed to graphite, 10 mg, developed Mycoplasma pulmonis . These observations offer an encouraging hypothesis in support of the possible effect upon Mycoplasma infection following exposure to particulate pollutants.