Effects Of Lactic Acid Bacteria Research Articles

Anti-Toxigenic Effect of Lactic Acid Bacteria Against Aspergillus spp Isolated from Wheat Grains

Introduction: Many fungi infect the wheat grains. Under field and or storage conditions from temperature and humidity, some fungi can produce aflatoxins (AFs), which may cause acute or chronic diseases. Therefore, there is a necessary and urgent need to find an effective and safe way to reduce or remove AFs. Objective: The objective of this study was the evaluation of Lactobacillus rhamnosus, Lactobacillus gasseri, and Lactobacillus plantarum for their ability to reduce and or remove AFs produced by Aspergillus flavus and Aspergillus parasiticus, which were isolated from wheat grains, as well as control of AFs produced on affected wheat grain by A.parasiticus spores only. Methods: LAB, isolated from some local dairy products, were cultured in MRS for the evaluation of their ability to remove AFs, produced by A. flavus and A. parasiticus on (YES) media, in addition to the treatment of wheat grains by LAB cells to prevent AFs produced by A. parasiticus. Results: The L. rhamnosus strain gave the highest reduction rates of AFs produced by A. parasiticus that were 62.6, 44.4, 43.3, and 52.2% for AFG1, AFB1, AFG2, and AFB2, respectively. While in the case of A. flavus, the reduction was 50.4, 42.7, 40.6, and 36.8% in the same order of toxins. When applied, these strains with wheat grains were affected by A. parasiticus, the inhibition rates of AFs were ranged between 61.4 and 75.8% with L. rhamnosus strain and 43.7 to 52.1% with L. gasseri, while L. plantarum strain ranged from 55.5 to 66.9%. Conclusion: According to this study, L. rhamnosus is considered one of the best strains in this field. Therefore, the present study suggests applied use of LAB as a treatment to prevent AFs production in wheat grains.

Effect of lactic acid bacteria on growth performance, oxidative status and infectious parameters induced by Listeria monocytogenes in broilers

Abstract This study aimed to investigate Enterococcus faecium ( E. faecium), Lactobacillus plantarum ( L. plantarum) or their combination on the growth performance, oxidation, inflammation and its in-depth mediators in broilers infected with Listeria monocytogenes ( L. monocytogenes). Six treatments were performed including negative control without and positive control with L. monocytogenes infection and supplementation with antibiotic enrofloxacin hydrochloride (40Â mg/kg of diet) or individual (10 8 cfu/kg of diet) or combined (at an equal amount, final dose 2.0×10 8 cfu/kg of diet) addition of E. faecium and L. plantarum using 360 broilers from 8 to 28 days of age. The L. monocytogenes infection was induced on the first day of the feeding trial. Results showed that the broilers of the positive control showed lower (p˂0.05) growth performance, but higher L. monocytogenes load in tissues compared to the negative control, while these parameters were partially reversed by supplemental lactic acid bacteria and antibiotic. The four supplements showed similar reduction (p˂0.05) effects on oxidative markers including diamine oxidase, malondialdehyde, and protein carbonyl, but the effects of antibiotic and E. faecium on protein carbonyl were more pronounced (p˂0.05). Also, the dietary treatments decreased (p˂0.05) interleukin (1β, 6) and tumour necrosis factor α, but upregulated (p˂0.05) the transcriptional levels of inflammatory mediators such as protein kinase B (PKB), mammalian target of rapamycin (mTOR), and ribosomal protein S6 kinase beta (RPS6KB). It is concluded that individual or combined E. faecium and L. plantarum are comparable to antibiotics on attenuating L. monocytogenes infection by activating PKB/mTOR/RPS6KB signaling in farm animals.

Pengaruh Penambahan Bakteri Asam Laktat dan Pakan Sumber Energi terhadap Kandungan Nutrisi dan Fraksi Serat Silase Pelepah Sawit

The purpose of this research was to evaluate the effects of Lactic Acid Bacteria (LAB) and the best energy-rich feed that could be combined with LAB on oil palm fronds (OPF) silage. Energy-rich feeds (molasses, rice polish, palm kernel cake (PKC), sludge and rice bran) were used and each of them was combined with LAB (Lactobacillus plantarum and Lactobacillus fermentum, 1010 CFU/mL). The treatments were : P0 = OPF, P1 = OPF + LAB (5 ml/kg), P2 = OPF + LAB (5 ml/kg) + molasses (3%), P3 = OPF (control) + LAB (5 ml/kg) + rice polish (3%), P4 = OPF + LAB (5 ml/kg) + BIS (3%), P5 = OPF + LAB (5 ml/kg) + sludge (3%), P6 = OPF + LAB (5 ml/kg) + rice bran (3%). Silages were packed in airtight transparent bottle silo (300 g capacity) and stored at room temperature. After 3 weeks, each silo was opened and sampled for physicals, nutrient and fiber analyses. Data were statistically analyzed in completely randomized design, and continued with orthogonal contrast analyses. The addition of LAB significantly (P<0.01) increased crude protein (CP), crude fibre (CF), acid detergent fibre (ADF), decreased hemicellulose but no significant effect on nitrogen-free extract (NFE) and neutral detergent fibre (NDF) content of OPF silages. The addition of energy-rich feeds significantly (P<0.01) increased CF and CP, decreased NFE, NDF and hemicellulose, but no significant effects on ADF of OPF silage. The most suitable energy-rich feeds combining with LAB in producing OPF silage was rice bran.

Short Communication: Oral Administration of Heat-killed Lactobacillus brevis KB290 in Combination with Retinoic Acid Provides Protection against Influenza Virus Infection in Mice.

Influenza virus type A (IAV) is a seasonal acute respiratory disease virus with severe symptoms, and an effective preventive measure is required. Despite many reports describing the potentially protective effects of lactic acid bacteria, few studies have investigated the effects of nutritional supplement combinations. This study reports the effect of the combined intake of heat-killed Lactobacillus brevis KB290 (KB290) and vitamin A (VA) on mice challenged with a sublethal dose of IAV. For 2 weeks, five groups of mice were fed either placebo, KB290, VA, or a combination of KB290 and VA (KB290+VA). After subsequent IAV challenge, bodyweight and general health were monitored for up to 2 weeks. Viral titres were determined in the lungs of animal subgroups euthanised at days 3, 7, and 14 after IAV challenge. A significant loss was observed in the bodyweights of IAV-infected animals from day 1 post-IAV challenge, whereas the mice fed KB290+VA did not lose any weight after IAV infection, indicating successful protection from the infection. Additionally, mice in the KB290+VA group showed the highest reduction in lung viral titres. In conclusion, the combination of KB290 and VA could be a useful food supplement relevant for protection against seasonal influenza virus infection in humans.

Effect of Lactic Acid Bacteria on the Lipid Profile of Bean-Based Plant Substitute of Fermented Milk.

Biological processes of legumes may change their nutritional value of lipids, but there is no research on the fatty acid profile and their position distribution in fermented beverages obtained from germinated bean seeds. The present study aimed to determine the effect of fermentation by Lactobacillus strains on the fatty acid profile and their positional distribution in triacylglycerols of beverage obtained from germinated bean “Piękny Jaś Karłowy” (Phaseolus vulgaris) fermented by Lactobacillus strains. The population of lactobacilli (the pour plate method), pH, the fatty acid profile (gas chromatograph with a flame ionization detector), and the positional distribution of fatty acids in triacylglycerols (GC-FID) were determined before and after the fermentation of received beverages. The fermentation of beverages did not change the lactobacilli population (over 7 log10 CFU/g), but changed pH (to 4.7–3.7 or 5.8–5.6), fatty acid profile, and the positional distribution of fatty acids were observed. The fermentation process contributed to an increase in the share of palmitic, stearic, and oleic acids in the fatty acid profile compared to that in raw bean seeds. The fermentation processes changed the share of individual acids in positions sn–1 and sn–3 depending on Lactobacillus strain used. Compared to non-fermented beverages, in most fermented beverages, a lower share of palmitic and stearic acids, as well as a higher share of oleic acid in the sn–2 were observed.

Effects of lactic acid bacteria on the quality of silage and health of ruminants

Silage is an essential part of the rations for ruminants. Preparation and production of high-quality silage is vital to improving the quality and efficiency of animal husbandry. The nutritive value and fermentation quality of silage is dependent on not only the type and quality of the forage crop, but also the ensiling technique and epiphytic microbiota. Lactic acid bacteria (LAB), as an important silage additive and feed probiotics, play an important role in improving the quality of silage forage and regulating the growth performance and health of ruminants. LAB offer various advantages for ruminants as potential probiotics and are able to improve nutrient acquisition, growth performance and immune function stimulation in ruminants. In this paper, we review the current knowledge on the effects of LAB on silage quality and ruminant health. The comprehensive and in-depth understanding of the biological functions of important microorganisms, like LAB, in the silage fermentation process, the mechanisms of action, and the physiological effects on ruminant health is useful for developing highly effective compound silage inoculants, and for providing a scientific basis for improving physiological health of ruminants.

Effect of Lb. plantarum BFE 5092 Fermentation on Antinutrient and Oligosaccharide Composition of Whole Red Haricot Bean (Phaseolus vulgaris L).

Common beans are a leguminous plant of the genus Phaseolus. They are rich in protein, energy, and minerals. They confer a wide range of health benefits when consumed. Utilization of common bean has however been poor due to high antinutrient content that results in reduced nutrient digestibility and mineral bioavailability. Flatulence after consumption is also a huge deterrent to common bean consumption. Lactic acid fermentation is the most common form of food fermentation with the Lactobacilli spp dominating most spontaneous fermentations. The objective of this study was to determine the effect of lactic acid bacteria (LAB) on the antinutrient and flatulence causing oligosaccharide composition of red haricot bean. A factorial research design was used in the study. Red haricot beans were sorted and soaked for 15 h. The soaked beans were fermented in 2% salt-sugar solutions for 120 h. Experimental batch was inoculated with Lb. plantarum BFE 5092 (IF), and the control batch was spontaneously fermented (SF). Microbial growth and pH were monitored every 24 h during fermentation. After fermentation, the beans were dried and milled, and the flours were subjected to biochemical analysis. ANOVA was done using SPSS statistics 23. The pH decreased significantly (P < 0.05) from 6.06 to 3.9 in both batches at the end of fermentation. The LAB counts significantly increased (P < 0.05) in both batches, whereas coliform counts decreased significantly (P < 0.05). Fungi were not detected in both batches. Soaking lowered tannins and phytates and raffinose concentrations significantly but had no significant effect on stachyose concentration. At the end of 120 h of fermentation, the tannin content was 109.50 and 54.04 mg/100 g in IF and SF, respectively. Phytates were at 242.52 and 163.43 mg/100 g in IF and SF, respectively. Raffinose content was 32.85 and 32.58 mg/100 g in IF and SF, respectively, while stachyose content was 593.33 and 467.49 mg/100 g in IF and SF, respectively. This research showed that LAB is able to ferment soaked whole red haricot and lower the tannin, phytate, raffinose, and stachyose content significantly. Spontaneous fermentation lowered these antinutrients and oligosaccharides better than inoculation with Lb. plantarum BFE 5092.

Evaluating the effects of lactic acid bacteria and olive leaf extract on the quality of gluten-free bread

Celiac disease is an autoimmune intestinal disease which usually occurs in susceptible individuals. This digestive disease damages the villi of the small intestine and impairs absorption of nutrients. Patients with celiac disease, cannot tolerate the gluten protein in the bread, and therefore, alternatives should be taken into consideration to improve the quality of gluten-free bread.In this study, the possibility of producing gluten-free bread with high quality and nutritional values, using corn-based and rice-based sourdough inoculated with Lactobacillus plantarum (ATCC 14917) and Lactobacillus fermentum (ATCC 9338) as starter cultures was investigated. In addition, the addition of 5% and 10% olive leaf extract using the encapsulation method was evaluated. Physicochemical properties of the prepared gluten-free bread, including moisture content, pH, Total Titratable Acidity (TTA), texture, and total acceptability of the bread based on odor, firmness, taste, chewability, and staleness were evaluated. Antifungal properties of the prepared breads were also determined. Each evaluation was performed in triplicates and the results were statistically analyzed using generalized linear model (GLM) by SPSS. Means were compared with Duncan's multiple range test at 95% Confidence Interval.According to the results, L. plantarum significantly decreased the pH values of the samples (p < .01). Also, sourdoughs prepared with L. plantarum showed a significantly higher TTA compared to those prepared with L. fermentum (p < .01). Breads in which olive leaf extract and lactic-acid bacteria (LAB) were used showed the highest moisture content (p < .01). Also, considering the sensory evaluation of the bread, the acceptability of the gluten-free bread increased with the increased levels of sourdough and olive leaf extract. Generally, the use of LAB-inoculated sourdough and olive leaf extract can improve the quality of the bread in regards to the taste, staleness, odor, chewability, softness, moisture content, pH, acidity and texture. Also, they can improve the antifungal properties of the bread, thereby increasing their shelf-life. Therefore, these ingredients as alternatives to gluten may be employed for improving the structure and acceptability of the gluten-free bread.

INTERACTION OF SELECTED LACTIC ACID BACTERIA AND YEAST IMPROVES THE QUALITY OF PEARL MILLET SOURDOUGH BREAD

The effect of lactic acid bacteria and yeast interaction on the quality of pearl millet (PM) sourdough bread was investigated. Lactobacillus plantarum (A), Pediococcus pentosaceus (B), Lactobacillus pentosus (C), Saccharomyces cerevisiae (D) and Candida milleri (E) cultures were used singly and in combinations in sourdough fermentation. The proximate, physical and sensory properties of bread were evaluated using standard methods. The protein content ranged from 13.07% - 14.32%, ash (1.77% - 1.99%), fat (8.01% - 9.32%), crude fibre (0.77% - 1.25%), moisture (21.08% - 22.65%), carbohydrate (51.28%- 54.23%), loaf weight (75.28 g-108.32 g), loaf volume (89 cm3 – 130 cm3) and specific volume (1.0 cm3/g - 1.26 cm3/g). PMABE (Pearl Millet + Lb. plantarum + Lb. pentosus + C. milleri) was scored acceptable. The crude protein, fat, ash, fibre content and specific volume differed depending on the type of starters used in the development of sourdough bread. The use of co-cultures as starters could improves the physicochemical quality and acceptability of sourdough bread. Saccharomyces cerevisiae have been implicated in dough development, however, this study have shown that Candida milleri could also be a substitute in dough development in the pastry industry.

The Potential Probiotic and Functional Health Effects of Lactic Acid Bacteria Isolated from Traditional Korean Fermented Foods

본 연구에서는 한국의 전통발효식품인 식해, 열무김치, 비지에서 분리한 유산균의 프로바이오틱스로써의 사용가능성을 확인하였다. 분리된 유산균 중 pH 2.5의 산에서 60% 이상의 생존율을 나타내는 Pediococcus inopinatus BZ4, Lactobacillus plantarum SH1, Lactobacillus brevis SH14, Pediococcus pentosaceus YMT1, Leuconostoc mesenteroides YMT2는 0.3% 담즙산에서도 모두 우수한 생존율을 나타내어 이 5종을 선별하여 실험을 진행하였다. 간접적으로 유용미생물의 군집화 및 병원성 세균의 부착을 저해하는 자가 응집 및 상호 응집 실험에서 다섯 개의 유산균은 강력한 응집능을 나타내었다. 유기용매를 이용한 세포 표면 소수성 실험에서 3가지 용매에 모두 부착성을 나타내어 세포 표면의 높은 소수성을 보여주었으며 이는 간접적으로 장세포에 부착할 수 있는 세포 부착능이 우수하다는 것을 보여준다. 또한, DPPH, ABTS 라디컬 소거능 측정, 지질 과산화억제능 실험에서도 선별된 유산균의 cell-free supernatant 및 intracellular cell-free extract는 항산화 활성을 나타내었다. 마지막으로 진균인 C. albicans ATCC 10231를 제외한 4가지 병원성세균(E. coli KCTC 2571, H. pylori HPKCTC B0150, L. monocytogenes KCTC 13064, S. aureus KCTC 1916)에서 모두 항균활성이 나타남을 확인하였다. 상기 실험결과를 바탕으로, 분리된 유산균은 항산화, 항균활성을 보유하고 있는 프로바이오틱스 제제로써 활용이 가능할 것으로 기대되며 이는 기초적인 실험으로써 산업화를 위한 임상검증 등의 추가적인 연구가 필요하다고 사료된다.

Exploring the wound healing, anti-inflammatory, anti-pathogenic and proteomic effects of lactic acid bacteria on keratinocytes

The topical application of lactic acid bacteria (LAB) is recognized as a useful approach to improve skin health. This work aims to characterize by a multidisciplinary approach, the wound healing, anti-inflammatory, anti-pathogens and proteomic effects of six LAB lysates, belonging to the genus Lactobacillus. Our results demonstrated that the lysates of tested LAB stimulated the proliferation of keratinocytes, and that L. plantarum SGL 07 and L. salivarius SGL 19 accelerated the re-epithelization by inducing keratinocyte migration. The bacterial lysates also reduced the secretion of specific pro-inflammatory mediators from keratinocytes. Furthermore, viable L. salivarius SGL 19 and L. fermentum SGL 10 had anti-pathogenic effects against S. aureus and S. pyogenes, while L. brevis SGL 12 and L. paracasei SGL 04 inhibited S. aureus and S. pyogenes, respectively. The tested lactobacilli lysates also induced specific proteome modulation of the exposed keratinocytes, involving dysregulation of proteins (such as interleukin enhancer-binding factor 2 and ATP-dependent RNA helicase) and pathways (such as cytokine, NF-kB, Hedgehog, and RUNX signaling) associated with their specific wound healing and anti-inflammatory effects. This study indicates the different potential of selected lactobacilli, suggesting that they may be successfully used in the future together with conventional therapies to bring relief from skin disorders.

Hepatoprotective effect of lactic acid bacteria in the attenuation of oxidative stress from tert-butyl hydroperoxide

The pathogenesis and progression of liver disease are associated with free radical injury and oxidative stress, which can be partially attenuated by antioxidants and free radical scavengers. Lactic acid bacteria, which have been traditionally used in the production of various fermented foods, are important intestinal microflora and natural antioxidants. The hypothesis that lactic acid bacteria can prevent or decrease tert-butyl hydroperoxide (r-BHP)-induced oxidative damage in HepG2 cells was investigated. Intracellular extracts and heat-killed cells of Lactobacillus acidophilus La12, Lactobacillus delbrueckii ssp. bulgaricus Lb23, Bifidobacterium longum Bl36 and Streptococcus salivarius ssp. thermophilus St28 were used in this study. Lactate dehydrogenase (LDH), alanine aminotransferase (ALT), reactive oxygen species (ROS), thiobarbituric acid reactive substances (TBARS), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GRd), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) were determined to explore the influence of lactic acid bacteria intervention on cell damage and antioxidative status. Toxic damage to hepatocytes by t-BHP was attenuated by lactic acid bacteria (which exerted protective effects by decreasing the risk of accumulated ROS and by reactivating antioxidant enzymes) in HepG2 cells treated with lactic acid bacteria before t-BHP exposure. The results of this study provide new insights into the mechanisms by which lactic acid bacteria with antioxidative properties can help to protect the liver.

In vitro effects of lactic acid bacteria on cancer cell viability and antioxidant activity

We used two local Lactobacillus strains (L. paracasei ssp. paracasei NTU 101 and L. plantarum NTU 102) and other 10 lactic acid bacteria (LAB) strains from the Biosource Collection and Research Center (BCRC) to evaluate the health promoting capability including inhibitory effects on cancer cell lines and antioxidant activities in vitro. The heat-killed cells (HKC) of Lactobacillus acidophilus BCRC14079 have the highest total antioxidative activity (82.3%). 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging effects were in the range of 14.8-32.9%, except for the HKC of L. salivarius ssp. salivarius BCRC 14759 and Bifidobacterium breve BCRC 11846. Twelve strains showed varying degrees of reducing activity. The reducing activity of cytoplasmic fraction (CF) of L. acidophilus BCRC 14079 was found to be significantly more pronounced (six-fold) than that of the HKC of B. adolescentis BCRC 14606, which was the lowest of all. In the cell viability, the inhibitory effects on cancer cells were very different which depended on various LAB strains. Flow cytometry study on human breast adenocarcinoma cells (MDA-MB-231) treated with local lactobacilli strains (L. paracasei ssp. paracasei NTU 101 and L. plantarum NTU 102) isolated in Taiwan showed the highest percentage of arrested at G0/G1 phase in the cell cycle. These results show that local lactobacilli strains have strong antioxidative and anticancer activities.

Antioxidative effect of lactic acid bacteria: Intact cells vs. intracellular extracts

The present study compared the anti-oxidative ability of intact cells and intracellular extracts of two lactic acid bacterial strains, Bifidobacterium longum and Lactobacillus delbrueckii ssp. bulgaricus. Results showed that both intact cells and intracellular extracts of 109 cells of B. longum and L. delbrueckii ssp. bulgaricus had the ability to scavengeα-diphenyl- β-picrylhydrazyl (DPPH) free radical by 70.4-75.1%, to inhibit liposome peroxidation by 25-31%, and to decrease significantly the malondialdehyde (MDA) production in Intestine 407 cells. The effect of intact cells and intracellular extracts of these two bacterial strains on the oxidation of low density lipoprotein (LDL) isolated from cerebrovascular accident (CVA) patients and healthy subjects was also compared. Oxidation of LDL was monitored by measuring the lag time for the formation of conjugated dienes in isolated LDL particles. When LDL was treated respectively with 109 intact cells of B. longum and L. delbrueckii ssp. bulgaricus, the lag time of oxidation of LDL was prolonged significantly. The extent of inhibition was greater on LDL isolated from healthy subjects than from CVA patients. When LDL from either CVA patients or healthy subjects was treated with intracellular extracts of 109 cells of B. longum and L. delbrueckii ssp. bulgaricus, respectively, the copper-mediated oxidation was extensively inhibited with a lag time exceeding 180 min. Results from this study show a greater inhibitory effect on LDL oxidation exerted by the intracellular extract than the intact cells, suggesting the presence of effective inhibitory factors in the intracellular extract.

Lactic Acid Bacteria as Antibacterial Agents to Extend the Shelf Life of Fresh and Minimally Processed Fruits and Vegetables: Quality and Safety Aspects.

Eating fresh fruits and vegetables is, undoubtedly, a healthy habit that should be adopted by everyone (particularly due to the nutrients and functional properties of fruits and vegetables). However, at the same time, due to their production in the external environment, there is an increased risk of their being infected with various pathogenic microorganisms, some of which cause serious foodborne illnesses. In order to preserve and distribute safe, raw, and minimally processed fruits and vegetables, many strategies have been proposed, including bioprotection. The use of lactic acid bacteria in raw and minimally processed fruits and vegetables helps to better maintain their quality by extending their shelf life, causing a significant reduction and inhibition of the action of important foodborne pathogens. The antibacterial effect of lactic acid bacteria is attributed to its ability to produce antimicrobial compounds, including bacteriocins, with strong competitive action against many microorganisms. The use of bacteriocins, both separately and in combination with edible coatings, is considered a very promising approach for microbiological quality, and safety for postharvest storage of raw and minimally processed fruits and vegetables. Therefore, the purpose of the review is to discuss the biopreservation of fresh fruits and vegetables through the use of lactic acid bacteria as a green and safe technique.

Lactic Acid Bacteria and Lactic Acid for Skin Health and Melanogenesis Inhibition.

Lactic acid bacteria are beneficial to human health. Lactic acid bacteria have wide applications in food, cosmetic and medicine industries due to being Generally Recognized As Safe (GRAS) and a multitude of therapeutic and functional properties. Previous studies have reported the beneficial effects of lactic acid bacteria, their extracts or ferments on skin health, including improvements in skin conditions and the prevention of skin diseases. Lipoteichoic acid isolated from Lactobacillus plantarum was reported to inhibit melanogenesis in B16F10 melanoma cells. In particular, lipoteichoic acid also exerted anti-photoaging effects on human skin cells by regulating the expression of matrix metalloproteinase- 1. The oral administration of Lactobacillus delbrueckii and other lactic acid bacteria has been reported to inhibit the development of atopic diseases. Additionally, the clinical and histologic evidence indicates that the topical application of lactic acid is effective for depigmentation and improving the surface roughness and mild wrinkling of the skin caused by environmental photo-damage. This review discusses recent findings on the effects of lactic acid bacteria on skin health and their specific applications in skin-whitening cosmetics.

Effects of lactic acid bacteria inoculant on quality, fermentation profile and nutritive value of alfalfa silage at different ensiling period

The present study was carried out to investigate the effects of lactic acid bacteria inoculant on quality, fermentation profile and nutritive value of alfalfa silage at different fermentation periods. After harvesting, fresh alfalfa samples were packed into polyethylene film and the commercial lactic acid bacteria inoculant was used as silage additive. Totally of 21 silage packages were opened by weekly for the analysis. Smell, color, structure, and total scores of alflalfa silage were significantly increased from the first week. Silage quality was determined medium at 7th day; good between 14th and 42th days; excellent at 49th day. The Flieg point was gradually increased after d 28 of ensiling (P&amp;lt;0.05). While pH was reduced at 5.15; NH3-N/TN content of alfalfa silage was increased at 15.70% at the end of the study. We observed an increase in acetate concentration and decrease in propionate and butyrate concentrations in the alfalfa silage. Lactate concentration was significantly increased on day 35 of the fermentation (P&amp;lt;0.05). Crude fiber (CF), crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), acid detergent fiber (ADF) contents of alfalfa silage were decreased, whereas nitrojen free extract (NFE) and non-fiber carbohydrate (NFC) were increased during ensiling period. According to our findings, fermentation period had a significant effect on digestible dry matter, dry matter intake and relative feed value of alfafa silage (P&amp;lt;0.05).

Effectiveness of Lactic Acid Bacteria to Improve Cyprinus carpio Fingerlings Resistance Against

Common carp (Cyprinus carpio) cultivation is often hampered by a disease attack, one of them is the attack of Edwarsiella tarda. Lactic acid bacteria (LAB) can be used as an alternative to prevent diseases in fish by increasing the body's resistance. This research aimed to determine the most effective isolates of LAB that increase of the resistance of carp fingerlings to the attack of E. tarda bacteria and see which isolates can produce the highest survival. The LAB isolates used were the result of isolation from the gut of carp. This study used a Completely Randomized Design (CRD) consisting of four treatments with three replications. The fish were immersed with different LAB isolates, CcB7, CcB8, and CcB15 in the same density of 108 cells / mm3. Immersion was carried out for 30 minutes with a frequency of seven days. While during the research, two immersions were carried out before the challenge test against E. tarda bacteria. The parameters observed were the number of leukocytes, hematocrit, erythrocyte, differential leukocytes, survival rate, and clinical symptoms that appeared. The results showed that all LAB isolates used in this study could increase the body resistance of carp against the attacks of E. tarda bacteria. The LAB CcB7 isolate was the most effective for enhancing the body resistance of carp fish withthe highest increase level of leukocyte, erythrocyte, and hematocrit were 18 ± 0.057,7 ± 0,077, and 0.26± 7.31% respectively. After being challenged with E. tarda bacteria producing mild clinical symptoms, the highest increase is in monocyte and neutrophil cells was 20 and 62% respectively, the highest reduction in lymphocytes was – 9% and the highest survival rate was 80%.

Validation via challenge test of a dynamic growth-death model for the prediction of Listeria monocytogenes kinetics in Pecorino di Farindola cheese

Pecorino di Farindola is a typical cheese produced in the area surrounding the village of Farindola, located in the Abruzzo Region (central Italy), unique among Italian cheese because only raw ewe milk and pig rennet are used for its production. In the literature it is well documented that raw milk is able to support the growth of pathogenic microorganisms such as Listeria monocytogenes. Predictive microbiology can be useful in order to predict growth-death kinetics of pathogenic bacteria, on the basis of known environmental conditions. Aim of this study was to compare predictions obtained from a model, originally designed to predict the kinetics of L. monocytogenes in the dynamic growth-death environment of drying fresh sausage, with the results of challenge tests performed during the ripening of Pecorino di Farindola produced from artificially contaminated raw ewe milk.A challenge test was carried out using ewe raw milk inoculated with L. monocytogenes, in order to produce Pecorino di Farindola cheese stored at 18 °C for 149 days of ripening. During the ripening period, pH and aw values decreased in all samples analysed; lactic acid bacteria become the prevailing microbial population, while for L. monocytogenes a period of stability (neither growth nor death) followed the initial situation. The growth inhibition and the following inactivation may mostly be due to competition with the autochthonous microbiota and to the reduction of water activity.Mathematical modelling was used in order to predict microbial kinetics in the dynamic ripening environment, joining growth and death patterns in a continuous way, and including the highly uncertain growth/no growth range separating the two regions. The effect of lactic acid bacteria on the growth of pathogens was also included. Predicted microbial kinetics were satisfactory, as confirmed by the absence of statistically significant difference between observed and predicted values (p > 0.05).The present study proved, via challenge tests, that a dynamic growth/death model, previously used for a meat product, can be fruitfully used in cheese characterized by active competitive microbiota and progressive drying during ripening.

Effect of lactic acid bacteria on Listeria monocytogenes infection and innate immunity in rabbits

The present study aimed to investigate the effect of probiotic lactic acid bacteria (LAB) addition on Listeria monocytogenes translocation and its toxin listeriolysin O (LLO), proinflammatory factors, immune organ indexes and serum immunoglobulins in farmed rabbits. Five treatments included negative control (NC), positive control (PC) with L. monocytogenes infection and supplemental LAB at 3.0 × 10&lt;sup&gt;6 &lt;/sup&gt;(low-LAB, L-LAB), 3.0 × 10&lt;sup&gt;8&lt;/sup&gt; (medium-LAB, M-LAB) and 3.0 × 10&lt;sup&gt;10 &lt;/sup&gt;(high-LAB, H-LAB) CFU/kg of diet, respectively. The LAB was a mixture of equal amounts of Lactobacillus acidophilus (ACCC11073), Lactobacillus plantarum (CICC21863) and Enterococcus faecium (CICC20430). A total of 180 weaned rabbits (negative for L. monocytogenes) were randomly assigned to 5 groups with 6 replicates of 6 rabbits each in response to the 5 treatments. L. monocytogenes infection occurred on the first day of feeding trial and dietary LAB supplementation lasted for 14 days. The results showed that on days 7 and 14 post administration, L. monocytogenes in caecum, liver, spleen and lymph nodes was reduced in M-LAB and H-LAB compared to PC (P &amp;lt; 0.05), and linear and quadratic reducing trends were found in liver on day 7 (P ≤ 0.002). On day 14, mucosa LLO mRNA expression and serum TNFα, IL1β and IFNγ were reduced in the three LAB treatments (P &amp;lt; 0.05), and linear and quadratic trends were found on TNFα and IL1β (P ≤ 0.025); indexes of thymus and spleen, serum IgA and IgG were increased in the LAB treatments (P &amp;lt; 0.05). It is concluded that LAB can be used to alleviate L. monocytogenes infection and to improve the immune function of farmed animals.