Lactic Bacteria Research Articles

Anti-Inflammatory and Immunomodulatory Properties of Fermented Plant Foods.

Fermented plant foods are gaining wide interest worldwide as healthy foods due to their unique sensory features and their health-promoting potentials, such as antiobesity, antidiabetic, antihypertensive, and anticarcinogenic activities. Many fermented foods are a rich source of nutrients, phytochemicals, bioactive compounds, and probiotic microbes. The excellent biological activities of these functional foods, such as anti-inflammatory and immunomodulatory functions, are widely attributable to their high antioxidant content and lactic acid-producing bacteria (LAB). LAB contribute to the maintenance of a healthy gut microbiota composition and improvement of local and systemic immunity. Besides, antioxidant compounds are involved in several functional properties of fermented plant products by neutralizing free radicals, regulating antioxidant enzyme activities, reducing oxidative stress, ameliorating inflammatory responses, and enhancing immune system performance. Therefore, these products may protect against chronic inflammatory diseases, which are known as the leading cause of mortality worldwide. Given that a large body of evidence supports the role of fermented plant foods in health promotion and disease prevention, we aim to discuss the potential anti-inflammatory and immunomodulatory properties of selected fermented plant foods, including berries, cabbage, and soybean products, and their effects on gut microbiota.

Probiotic properties of an indigenous Pediococcus pentosaceus strain on Tenebrio molitor larval growth and survival

Optimising the production of insects for food and feed and ensuring their health are growing concerns for producers. Insects suffer from a range of insect pathogenic microorganisms, and the management of such diseases is essential. One solution is the introduction of beneficial probiotic bacteria into the diet of the insects. Here, we show that a lactic acid bacterial strain, Pediococcus pentosaceus, isolated from the gut of the mealworm, Tenebrio molitor, was able to inhibit the growth of selected insect pathogens in vitro. Using in vivo assessments of the host’s fitness benefits conferred by the lactic bacterium we show a significant effect of P. pentosaceus on larval growth rate and survival into adulthood. Gut microbiota analysis focusing on bacterial composition based on 16S rRNA gene amplicon sequencing suggests that P. pentosaceus could have successfully colonised the guts, or altered their bacteria, of the larvae that received it. Finally, we discuss our results in the context of mass insect production systems and outline the remaining work needed to explore and secure the role of beneficial bacterial additives in the field.

Metformin and Probiotics Interplay in Amelioration of Ethanol-Induced Oxidative Stress and Inflammatory Response in an In Vitro and In Vivo Model of Hepatic Injury.

Alcohol-induced liver injury implicates inflammation and oxidative stress as important mediators. Despite rigorous research, there is still no Food and Drug Administration (FDA) approved therapies for any stage of alcoholic liver disease (ALD). Interestingly, metformin (Met) and several probiotic strains possess the potential of inhibiting alcoholic liver injury. Therefore, we investigated the effectiveness of combination therapy using a mixture of eight strains of lactic acid-producing bacteria, commercialized as Visbiome® (V) and Met in preventing the ethanol-induced hepatic injury using in vitro and in vivo models. Human HepG2 cells and male Wistar rats were exposed to ethanol and simultaneously treated with probiotic V or Met alone as well as in combination. Endoplasmic reticulum (ER) stress markers, inflammatory markers, lipid metabolism, reactive oxygen species (ROS) production, and oxidative stress were evaluated, using qRT-PCR, Oil red O staining, fluorimetry, and HPLC. In vitro, probiotic V and Met in combination prevented ethanol-induced cellular injury, ER stress, oxidative stress, and regulated lipid metabolism as well as inflammatory response in HepG2 cells. Probiotic V and Met also promoted macrophage polarization towards the M2 phenotype in ethanol-exposed RAW 264.7 macrophage cells. In vivo, combined administration of probiotic V and Met ameliorated the histopathological changes, inflammatory response, hepatic markers (liver enzymes), and lipid metabolism induced by ethanol. It also improved the antioxidant markers (HO-1 and Nrf-2), as seen by their protein levels in both HepG2 cells as well as liver tissue using ELISA. Hence, probiotic V may act, in addition to the Met, as an effective preventive treatment against ethanol-induced hepatic injury.

Development of Electrochemical DNA Biosensor for Equine Hindgut Acidosis Detection.

The pH drop in the hindgut of the horse is caused by lactic acid-producing bacteria which are abundant when a horse’s feeding regime is excessively carbohydrate rich. This drop in pH below six causes hindgut acidosis and may lead to laminitis. Lactic acid-producing bacteria Streptococcus equinus and Mitsuokella jalaludinii have been found to produce high amounts of L-lactate and D-lactate, respectively. Early detection of increased levels of these bacteria could allow the horse owner to tailor the horse’s diet to avoid hindgut acidosis and subsequent laminitis. Therefore, 16s ribosomal ribonucleic acid (rRNA) sequences were identified and modified to obtain target single stranded deoxyribonucleic acid (DNA) from these bacteria. Complementary single stranded DNAs were designed from the modified target sequences to form capture probes. Binding between capture probe and target single stranded deoxyribonucleic acid (ssDNA) in solution has been studied by gel electrophoresis. Among pairs of different capture probes and target single stranded DNA, hybridization of Streptococcus equinus capture probe 1 (SECP1) and Streptococcus equinus target 1 (SET1) was portrayed as gel electrophoresis. Adsorptive stripping voltammetry was utilized to study the binding of thiol modified SECP1 over gold on glass substrates and these studies showed a consistent binding signal of thiol modified SECP1 and their hybridization with SET1 over the gold working electrode. Cyclic voltammetry and electrochemical impedance spectroscopy were employed to examine the binding of thiol modified SECP1 on the gold working electrode and hybridization of thiol modified SECP1 with the target single stranded DNA. Both demonstrated the gold working electrode surface was modified with a capture probe layer and hybridization of the thiol bound ssDNA probe with target DNA was indicated. Therefore, the proposed electrochemical biosensor has the potential to be used for the detection of the non-synthetic bacterial DNA target responsible for equine hindgut acidosis.

Effects of Different Controlled Temperatures on Spanish-Style Fermentation Processes of Olives.

This work aimed to determine the effect of applying different temperatures during the fermentation process of Spanish-style table olives. ‘Manzanilla de Sevilla’ (southwest of Spain, Badajoz) and ‘Manzanilla Cacereña’ (northwest of Spain, Caceres) olives were processed at an industrial scale in table olive fermenters whose brine was subjected to different thermal treatments. One of the three conducted experiments found that maintaining brine at 20–24 °C over a 3-month period led to optimum firmness, better color indices, and greater free acidity and lactic acid bacteria populations in comparison to an unheated control. Furthermore, raising the temperature of the fermenter to 20–24 °C accelerated the fermentation process, provoking better lactic bacteria and yeast growth without affecting olive firmness. The higher fermentation rate (shorter time to completion) associated with temperature-controlled olives also reduced the marketing time of the final product. Controlling brine temperature led to a better aspect and color, higher acidity, lower bitterness, and better overall assessment of processed olives. In addition, ‘Manzanilla de Sevilla’ olives presented a higher phenolic content than ‘Manzanilla Cacereña’ olives. Preliminary evidence is presented suggesting that ‘Manzanilla Cacereña’ olives appear highly amenable to Sevillian-style processing. The present innovative work demonstrates the importance of applying different thermal treatments to brine to control the temperature during the industrial fermentation of table olives during the cold season.

Lactobacillus acidophilus LA5 improves saturated fat-induced obesity mouse model through the enhanced intestinal Akkermansia muciniphila

Obesity, a major healthcare problem worldwide, induces metabolic endotoxemia through the gut translocation of lipopolysaccharides (LPS), a major cell wall component of Gram-negative bacteria, causing a chronic inflammatory state. A combination of several probiotics including Lactobacillus acidophilus 5 (LA5), a potent lactic acid-producing bacterium, has previously been shown to attenuate obesity. However, data on the correlation between a single administration of LA5 versus microbiota alteration might be helpful for the probiotic adjustment. LA5 was administered daily together with a high-fat diet (HFD) for 8 weeks in mice. Furthermore, the condition media of LA5 was also tested in a hepatocyte cell-line (HepG2 cells). Accordingly, LA5 attenuated obesity in mice as demonstrated by weight reduction, regional fat accumulation, lipidemia, liver injury (liver weight, lipid compositions, and liver enzyme), gut permeability defect, endotoxemia, and serum cytokines. Unsurprisingly, LA5 improved these parameters and acidified fecal pH leads to the attenuation of fecal dysbiosis. The fecal microbiome analysis in obese mice with or without LA5 indicated; (i) decreased Bacteroidetes (Gram-negative anaerobes that predominate in non-healthy conditions), (ii) reduced total fecal Gram-negative bacterial burdens (the sources of gut LPS), (iii) enhanced Firmicutes (Gram-positive bacteria with potential benefits) and (iv) increased Verrucomycobia, especially Akkermansia muciniphila, a bacterium with the anti-obesity property. With LA5 administration, A. muciniphila in the colon were more than 2,000 folds higher than the regular diet mice as determined by 16S rRNA. Besides, LA5 produced anti-inflammatory molecules with a similar molecular weight to LPS that reduced cytokine production in LPS-activated HepG2 cells. In conclusion, LA5 attenuated obesity through (i) gut dysbiosis attenuation, partly through the promotion of A. muciniphila (probiotics with the difficulty in preparation processes), (ii) reduced endotoxemia, and (iii) possibly decreased liver injury by producing the anti-inflammatory molecules.

Effect of Age on the Immune and Visceral Organ Weights and Cecal Traits in Modern Broilers.

Simple SummaryCurrently, due to the high developments achieved in the poultry industry especially in genetics, management, nutrition, health, and animal welfare, modern broilers reach slaughter weight at an earlier age, which in turn has brought about notable changes in the morphophysiology of these birds. The following research proposes to determine the effect of age on visceral and immune organ weight, cecal pH, and cecal lactic acid bacteria in Ross 308® broilers, up to 10 days old. It was concluded that the immune and visceral organs increase their absolute and relative weight according to age and on days 9 and 10 the highest growth rate of the organs was found, furthermore, the colonization of the cecal lactic acid bacteria is established before 10 days of life (as the most critical stage), although with variable changes for intestinal pH. The correlation showed, in addition, a significant association between the organs evaluated, as well as for the cecum relative weight and the cecal lactic bacteria count. These results could contribute to updating knowledge on immunological activity, cecal microbiology, and the functioning of the digestive system, as well as for the development of new nutritional requirements and the optimization of dietary formulations.This study aimed to determine the effect of age on the immune and visceral organ weights and cecal traits in modern broilers. 200 male Ross® 308 broilers were randomly selected, then 20 broilers were slaughtered every day (up to 10 days old) after six hours of fasting. All the organs measured had a progressive increase in absolute weight as the days progressed, apart from the spleen, which decreased its absolute weight on day 5, even though on day 10 it showed the highest values. Moreover, the small intestine relative weight increased from the fourth to the ninth day and was correlated (p ≤ 0.05) with the relative weight of the proventriculus, gizzard, small intestine, and cecum, although without statistical association with the of the heart. There was a correlation between the cecum relative weight and the cecal lactic acid bacteria, and between the primary lymphoid organs. The pH (from 5.74 to 7.40) and cecal lactic acid bacteria (from 6.11 to 8.79 log 10 CFU/g) changed according to the age of the broilers. The results could contribute to the understanding of the physiology and intestinal microbiology of the first 10 days old of modern broilers, which is crucial to improve the genetic expression of these animals.

Quantitative Real-Time PCR and Digital PCR to Evaluate Residual Quantity of HAV in Experimentally Depurated Mussels

Kinetics of hepatitis A virus (HAV) accumulation and depuration from mussels (Mytilus galloprovincialis) was studied in an experimental depuration system. Different parameters likely to influence the rate of virus accumulation and elimination were evaluated. Analyses were carried out by both real-time RT-qPCR and digital PCR. Results demonstrated that the animals start to concentrate the virus already after one hour and reach the maximum level of contamination in 6h of experiment. With respect to depuration, HAV showed a rapid reduction of the concentration (89%) during the first 24-48h of experiment and a very slow virus decrement in the following days with a 1% residual RNA at the ninth day of depuration. When process parameters likely to increase the depuration rate (presence of ozone, microalgal feeding, presence of lactic bacteria, pre-treatment with digestive enzymes) were tested, no significant differences in the kinetics were observed. Only treatment with pancreatin seemed to positively affect depuration in the first two days of the experiment.

Identification of a Lactococcus lactis Isolated from a Fresh Local Cheese of the Western Algerian Steppe “J’ben of Naama”

Background: The purpose of the study is to evaluate the diversity of lactococci, lactic bacteria, recovered from “J’ben”, a local cheese made from the milk of the Rembi sheep breed, a product of exploitation in the Algerian steppe regions of Naama.Methods: The bacterial species were isolated from samples of the recovered cheese exploitation and analyzed using genotypic methods. The isolation of bacterial DNA from purified Lactococcus cultures has been established by an amplification of ribosomal DNA 16s using the specific universal primers of prokaryotes. Result: The 16s DNA sequencing of all isolates, for genotypic identification, confirmed the predominance of Lactococcus lactis. This lactic dominance determines the quality and distinctiveness of this cheese in the region. The results obtained from acidification and proteolysis kinetics met the technological requirements and good functionality, from the strains used individually and in mixed culture to the cheese processing.

Effects of Ethanol-Precipitated Argan Press Cake on the Caecal Microbiome of Mice Fed a High-Sucrose Diet

Argan press cake (APC) is a by-product of argan oil extraction and is rich in cellulose, proteins, sucrose, phenolic compounds, and excessively bitter and acrid triterpenoids. Improvement in the antioxidant property of APC by fermentation (F-APC) with Lactiplantibacillus plantarum Argan-L2 has been reported. However, the bitter and acrid tastes remain in F-APC. Here, in order to determine the applicability of APC and F-APC as functional food materials by reducing its bitter taste, the effects of ethanol-precipitated APC and F-APC on mice fed a high-sucrose and low-fibre diet were determined. Compounds precipitated from 10% (w/v) APC and F-APC water suspensions with two volumes of ethanol were collected (APC-P, F-APC-P). The Institute of Cancer Research (ICR) mice were fed 50% (w/w) sucrose with no fibre (NF), 5% APC-P, or 5% F-APC-P for 14 days. The caecal microbiome was analysed via 16S rDNA (V4 region) sequencing. No bitter and acrid tastes were detected in the precipitates. Compared with those in the NF group, defaecation and the faecal weight were increased in the APC-P and F-APC-P groups. Additionally, blood lipid and glucose levels tended to be lower in the F-APC-P group. The abundance of caecal lactic acid-producing bacteria, such as Faecalibaculum rodentium and Lactobacillus johnsonii-like bacteria, was high in the APC-P group. In contrast, the abundance of indigenous L. plantarum-like bacteria was high in the F-APC-P group. APC-P and F-APC-P showed dietary fibre properties. Furthermore, APC-P and F-APC-P increased indigenous lactic acid bacteria OTUs, although the increased species were different in the two groups. These results suggest that both APC-P and F-APC-P have beneficial effects on the gut microbiome, environment, and host.

Active packaging based on cellulose trays coated with layered double hydroxide as nano‐carrier of parahydroxybenzoate: Application to fresh‐cut iceberg lettuce

Layered double hydroxide (LDH) as nano‐carrier of parahydroxybenzoate (listed in EC Directive 10/2011) was coated on a biodegradable film of cellulose acetate, coupled with compostable cellulose cardboard and trays realized. The sustained release of parahydroxybenzoate ionically intercalated into the LDH resulted significantly slower than the parahydroxybenzoate free dispersed into the coating medium. Such active packaging showed significant antimicrobial activity against Salmonella enterica Typhimurium, Escherichia coli, Listeria monocytogenes and Lactobacillus sakei. It was more than one in all cases, ranging from 1.1 for E. coli to 2.6 for S. enterica Typhimurium. Overall migration tests in ethanol at 50% (v/v), as food simulant, showed that the prepared packaging is suitable for food contact, being the migrated amount below the limits imposed by the EU regulation. Fresh‐cut iceberg lettuce was packed into the prepared active packaging and in a control packaging with no active coating and stored in condition of thermal stress (i.e. 10°C). Organoleptic characteristics and the evolution up to 14 days of mesophilic lactic bacteria, total bacteria count, yeasts and moulds showed a significant inhibition of such strains from the active filler. Comparing the lettuce packed in control and active packaging, for mesophilic lactic bacteria, it was found a delta log of 0.24 (CFU), and for the total bacteria count, a delta log of 1.63 (CFU). The most significant effects were observed respect to yeasts and moulds and yeasts counts. For yeasts, it was observed a delta log of 2.32 (CFU), and for yeasts and moulds, a delta log of 2.5 (CFU). The prediction of the shelf life of the lettuce was done following the growth of E. coli up to 30 days through the Gompertz equation. It was found a prolongation of the shelf life from 11 to 16 days

Processed by-Products from Soy Beverage (Okara) as Sustainable Ingredients for Nile Tilapia (O. Niloticus) Juveniles: Effects on Nutrient Utilization and Muscle Quality.

Simple SummaryThe consumption of soy products increases worldwide and generates large amounts of by-products, which are often discarded. Okara is a soybean by-product with high nutritional value. This work evidenced the great potential of okara meal, after appropriate technological processing, to be used as feed ingredient in Nile tilapia diets. It was clearly demonstrated the effectiveness of the autoclave and the use of proteases from C. cardunculus without fermentation to increase okara nutrient bioavailability. The inclusion of up to 20% okara meal in diets for tilapia did not affect growth performance, nutrient utilization, or whole body composition compared to a reference diet. Flesh quality remained largely unaffected, although fish fed with AOK diets had the highest density of muscle fibers.The apparent digestibility coefficients (ADCs) of differently processed okara meals were assessed in Nile tilapia diets: dried okara not autoclaved (FOK), dried okara autoclaved (AOK), okara hydrolyzed with Alcalase (ALOK) or Cynara cardunculus proteases (CYOK), and hydrolyzed okara fermented with lactic bacteria: Lactobacillus rhamnosus R11 (CYR11OK) or Bifidobacterium animalis ssp. lactis Bb12 (CYB12OK). Okara processing significantly affected nutrient digestibility: dry matter ADC was highest in CYR11OK (80%) and lowest in FOK (40%). The lowest protein digestibility was observed in CYR11OK (72%), and the highest in AOK (97%) and CYOK (91%), evidencing the effectiveness of the autoclave and the use of C. cardunculus proteases to increase okara protein bioavailability. The inclusion of up to 20% of AOK or CYOK did not affect fish growth, nutrient utilization, or whole body composition of Nile tilapia. The flesh quality (color, pH, water activity, cohesiveness, elasticity and resilience) was not affected by the dietary incorporation of AOK or CYOK. Fish fed with AOK diets stand out for their high density of muscle fibers, particularly in AOK20, which can explain their high muscle firmness and may result in further hypertrophic growth. Altogether, results suggest that hydrolyzed or autoclaved okara are valuable ingredients for Nile tilapia diets.

The combined effect of fermentation of lactic acid bacteria and in vitro digestion on metabolomic and oligosaccharide profile of oat beverage

Oat (Avena sativa L.) is widely appreciated for its beneficial properties for human health, which have led to the introduction of more food products on the market, including oat beverages. The fibre components found in the oat are recognized for their beneficial effects, despite other bioactive compounds with healthy properties being present. This work aimed to evaluate the metabolites profile of a commercial oat beverage, either fermented with lactic bacteria or not, following in vitro gastro-intestinal digestion. UHPLC-QTOF untargeted metabolomics allowed investigation of the bioaccessibility of health-related metabolites from the oat beverage at the intestinal level. The results identified flavonoids, phenolic acids (avenanthramides), amino acids and steroids as the major classes of compounds. In particular, after in vitro digestion, amino acids, peptides, and phenolic acids showed the highest increases. The co-fermentation of oat milk by Lactobacillus spp. and Bifidobacterium spp. strains decreased the levels of both lignans and phytic acid, while increased the levels of some polyphenols like avenanthramides. Furthermore, fermentation by microorganisms increased the bioaccessibility of specific amino acids, vitamins, and polyphenols (flavonoids and phenolic acids). Interestingly, despite lacking a significant part of beta-glucans, the HPAEC-PAD profiling of our oat beverage evidenced that the fermentation process did not alter the oligosaccharides profile, thus preserving its prebiotic potential. The phytochemical profile of oat milk was shown to have a functional potential. Nonetheless, the fermentation by bacterial strains changed the profile of metabolites during in vitro digestion, thus offering an interesting option in the future development of cereal-based beverages.

Cultivos lácticos como potenciadores de compuestos bioactivos de avena

The objective of this work was to study lactic fermentation as a biostrategy to enhance the antioxidant activity of oats. The adaptability of 31 strains of lactic bacteria (LB) in an oats/water system (OWS/SAA) was evaluated, measuring growth, acidification and fermentation activity (impedimetric method; detection time [DT], maximum rate of conductance change [MRCC/VMCC] and percentage of conductance change [PCC]). Moreover, the content of phenolic compounds (PC) was determined using the Folin-Ciocalteu method (gallic acid equivalents [GAE]), free peptides and amino acids and free radical scavenging activity (DPPH• and ABTS•+ methods) of methanolic and aqueous extracts obtained from fermented OWS/SAAs (fOWS/SAAf) were determined. Six strains have shown the best adaptability to SAA, with high values of VMCC (0.34-0.47 μS/min) and PCC (53.6-66.6%), and low values of DT (≤ 3 h). In these f/OWS/SAAf the chemical composition was also modified (PC concentration, peptides and free amino acids) with strain-dependent behavior. The PC content in f/OWS/SAAf using these six strains (29.1-36.9 μg GAE/ml) was higher than the control content in OWS/SAA control (17.1 ± 1.9 μg GAE/ml). An increase (9-25.5%) in antioxidant activity in f/OWS/SAAf methanolic extracts was detected using both methods. Minor modifications were observed in the peptide and free amino acid content of SAA and their antioxidant activity. Our results show LB ability to adapt to oat as fermentation substrate and increase the content of its antioxidant compounds.

Health and Nutritional Qualities of Drinks Produced in the Beninese Brewery Company and Those Sold on the Benin Market

Aims: This study aims to evaluate the microbiological, physicochemical and sensory qualities of beverages sold on the market in Benin.
 Study Design: The biological material used consisted mainly of beverage samples (126) collected at random from three wholesalers at the points of sale on two different occasions (regular period of 15 days) at the Dantokpa international market in Cotonou (Benin) in between April and September 2019.
 Place and Duration of Study: This study was conducted between April and December 2019 at the Food Safety Research, Laboratory of Microbiology and Food Technologies, Department of Plant Biology, Faculty of Science and Technology, University of Abomey-Calavi, Benin.
 Methodology: Microbiological, physicochemical and sensory qualities of samples were evaluated.
 Results: The results of the microbiological analyzes revealed that all the drinks analyzed contained neither the total mesophilic aerobic flora, nor wild yeast, saccharomyces nor lactic bacteria. Therefore, the drinks are free from all pathogenic microorganisms that may harm the health of consumers. These products sold on the market complied with the criteria set by the standards and were therefore of satisfactory hygienic quality. However, the physicochemical parameters of the various drinks analyzed varied significantly from one brand to another. Results showed that the Nigerian Guinness produced contained more foam (287 s at 20 °C) and was rich in Diacetyl (0.119 mg / l) than the Benin Guinness (0.050 mg / l). As for the beer "La Béninoise", it produced more foam (220 s at 20 °C) than the Goldberg (209 s at 20 °C) but less than the Satzenbrau (250 s at 20 °C). The beer "La Béninoise" was less rich in Diacetyl (0.026 mg / l) and shown more than Goldberg (0.047 mg/l) and Satzenbrau (0.034 mg/l). As for the types of mixed drinks, it is the star Radler of Nigeria which presented a beautiful foam (235 s at 19.9 °C) with a cloudy aspect compared to the variegated one of Benin (227 s at 20.1 °C). Sensory analysis revealed that Beninese Brewery Company drinks were more appreciated by tasters.
 Conclusion: In view of these results, all the beverages analyzed can be recommended to consumers because most of these drinks are of satisfactory quality and consistent with the standards.

Acute oral treatment with resveratrol and Lactococcus Lactis Subsp. Lactis decrease body weight and improve liver proinflammatory markers in C57BL/6 mice.

The present study aimed to evaluate the effects of resveratrol, a nutraceutical polyphenol, and Lactococcus lactis (bacteria probiotic), on metabolic parameters and hepatic proinflammatory markers expression. C57BL/6 mice were divided into 4 groups: Standard (ST), Lactococcus lactis (LL), Resveratrol (RSV), and Lactococcus lactis plus resveratrol (LL + RSV). Lactococcus lactis and resveratrol were administered by orogastric gavage. Blood parameters were assessed (total cholesterol, triglycerides, ALT and AST). IL-6 mRNA expression was evaluated by Real-time PCR and TNF-α protein expression was assessed by immunohistochemistry. The main findings showed that resveratrol and Lactococcus lactis association decreased body weight, aspartate aminotransferase and total cholesterol levels. LL and LL + RSV decreased triglycerides levels and IL-6 and TNF-α expression. These results open a perspective of using resveratrol and Lactococcus lactis to improve metabolic parameters and Lactococcus lactis in preventing inflammation and the hepatic diseases development.

The possible use of probiotics in the biotechnology of food products

The article represents the results of the research aimed to study the possible use of probiotics in the development of biotechnology for producing soft rennet cheeses with increased biotechnological value. The researchers found that the use of yeast consisting of L. Lactis and B. Subtilis made cheeses ripen faster and achieve the desired values of active and titratable acidity quicker. In control and experimental samples the ripening process took 8 hours while for other rennet cheeses with other probiotic consortiums including L. Lactis it took 12–14 hours to ripe. The addition of B. Subtilis to soft rennet cheese makes cells of probiotic cultures grow faster and more abundantly in comparison to the control sample. However, the microbiological analysis showed that at the end of the ripening process the number of L. Lactis bacteria cells, as well as B. Subtilis in experimental samples was higher than in the control sample by 0.5 and 1.2l g CFU/g respectively. The organoleptic evaluation showed that among seven samples of cheese the sixth sample had the best colour, smell, taste, consistency, pattern, and appearance. The sample had a sweetish cheesy taste, a tender homogeneous plastic consistency, a uniform white colour with holes of irregular, angular, slotlike, and oval forms of 1–2mm. The most rational concentration of Bacillus subtilis (strain 534) bacteria is 5 %. In this case 1ml contains 480 thousand microbial cells. This concentration gives a product a moderately marked cheesy, spicy taste that is inherent to soft cheeses. This indicates the feasibility of using Bacillus subtilis bacteria (strain 534) in the 5 % amount by milk weight.

Caracterización de bacterias ácido lácticas con actividad antimicrobiana aisladas del queso crema de Chiapas, México

El queso crema de Chiapas es un producto artesanal fabricado en diferentes regiones de México. La capacidad de las bacterias lácticas, de producir grandes cantidades de ácido láctico y acético, tiene como efecto la disminución del pH, considerado uno de los factores primarios en la inhibición de microorganismos indeseables, como patógenos y bacterias coliformes, en alimentos lácteos. El objetivo de este trabajo fue aislar bacterias ácido lácticas y evaluar su efecto antagónico contra bacterias patógenas in vitro y contra patógenos presentes en la leche cuando se adicionan durante la elaboración del queso crema. Se aislaron cepas de bacterias lácticas del queso crema de Chiapas, México. Los aislados fueron identificados mediante pruebas bioquímicas API 50CH y secuencias del gen ribosomal 16S. Las bacterias de interés se usaron en pruebas de inhibición del crecimiento con cepas patógenas. Se cuantificó la producción de ácido acético y láctico por cromatografía de gases acoplado a masas en los quesos, al inicio y a los 10 d posteriores a su elabo­ra-ción. Se aislaron 203 cepas bacterianas, de las cuales 82 tuvieron la capacidad de inhibir el crecimiento de 7 cepas bacterianas patógenas. Las cepas fueron identificadas por la secuencia parcial del gen ribosomal 16S como pertenecientes al género Lactobacillus; la adición de estas cepas en la elaboración del queso crema redujo o eliminó coliformes, Staphylococcus aureus, mohos y levaduras, mientras que en el queso elaborado con leche pasteurizada se detectaron 290 UFC/mL de mohos y levaduras. Estos resultados sugieren que las cepas de Lactobacillus aisladas del queso crema artesanal de Chiapas tienen potencial para su uso como cultivo iniciador con actividad de bioconservación en este y productos similares.

Bee pollen as a novel substrate in pilot-scale probiotic-mediated lactic fermentation processes

Different process conditions were evaluated to induce lactic acid fermentation of bee pollen at the pilot scale using three different commercial starter cultures. Clean and dry Colombian high Andean bee pollen was used as the sole source of nutrients (substrate). The effect of substrate preparation conditions (water:pollen ratio and initial substrate acidity) on lactic fermentation was evaluated by monitoring pH, titratable acidity, and pollen morphology in 6-kg-fermentation units. A 2:1 water:pollen mixture with an initial pH adjusted to 5.8, pretreated with heat/pressure (10 min; 80 kPa; 115 °C), was determined to be an adequate substrate for pilot-scale lactic fermentation for all lactic starter cultures. At the selected conditions, the kinetics of lactic acid production and the growth of specific lactic bacteria were determined. The fermentation process time was 30 h, after which a significant decline in bacterial populations was observed. Among the starter cultures tested, one constituted exclusively by probiotic Lactobacillus acidophilus NCFM presented the best performance in terms of lactic acid production, with a concentration of 1.65% wt, after 30 h. The results highlight the feasibility of producing fermented bee pollen at a commercial scale as a functional food product with probiotic features.

The vaginal microflora changes in various stages of the estrous cycle of healthy female dogs and the ones with genital tract infections

BackgroundInflammatory diseases of reproductive tract in bitches are a common problem in veterinary practice. The inflammation can lead to serious health problems. Research to determine the correlation between the health status of females, phase of the cycle, age and bacterial flora of the genital tract has been ongoing for years, but the results obtained by individual authors are often contradictory.ResultsA total of 39 dogs were included in this study. Ten were qualified to the 1st group with genital tract infections (8 in anestrus and 2 in proestrus) and 29 to the 2nd group without such infections (16 in anestrus, 9 in proestrus and 4 in diestrus). The most common bacterial isolates obtained from the vaginal tract of all dogs were Escherichia coli, Staphylococcus pseudintermedius and Streptococcus canis. The prevalence of Gram-negative rods (other than E. coli) was significantly higher in the group with genital tract infections versus healthy dogs. There was no presence of Chlamydiaceae, Chlamydia abortus and lactic acid-producing bacteria in tested swabs.ConclusionsOur study identified the most common bacteria in the genital tract of bitches. The total number of bacteria was almost the same in the healthy and infected dogs, as well as between the cycle stages. In our opinion, bacterial culturing of vaginal swab specimens from bitches without signs of genital disease is of little value. Furthermore, it should always be preceded by clinical examination and cytological examination of the vaginal epithelium.