Ability Of Lactic Acid Bacteria Research Articles

Investigating acrylamide mitigation by potential probiotics Bifidobacterium breve and Lactiplantibacillus plantarum: Optimization, in vitro gastrointestinal conditions, and mechanism

This paper investigated the ability of lactic acid bacteria (LAB) and Bifidobacterium to remove acrylamide (AA). The mechanism(s) of the AA removal was examined by various microscopic techniques. After screening 40 isolates, Bifidobacterium breve and Lactiplantibacillus plantarum exhibited higher acrylamide (AA) reduction by 35% and 36%, respectively. pH (4.5–6.5), incubation temperature (32–42 °C), incubation time (14–22 h), and NaCl (0–3 g/100 g) were employed using Box-Behnken design (BBD) to investigate the AA removal. As a result, the AA removal ranged from 47.7 to 65.0% for B. breve and 5.8%–8.0% for Lb. plantarum. Under the in vitro gastrointestinal conditions, B. breve removed up to 41.2% of acrylamide while Lb. plantarum reduced around 53.5% of acrylamide. In addition, both strains tolerated low pH levels. TEM images showed that cells of both bacteria increased after culturing with acrylamide. Elements analysis of Lb. plantarum and the most dominant elements are C, N, and O with atomic % of 41.95, 17.63, and 31.66, respectively. FTIR exhibited that CO, C–O, and N–H were main functional groups associated with AA adsorption in Lb. plantarum and B. breve. The zeta potential values of B. breve and Lb. plantarum are −15.47 and −25.87 mV, respectively.

Anti-biofilm potential of Lactobacillus plantarum Y3 culture and its cell-free supernatant against multidrug-resistant uropathogen Escherichia coli U12

Uropathogens develop biofilms on urinary catheters, resulting in persistent and chronic infections that are associated with resistance to antimicrobial therapy. Therefore, the current study was performed to control biofilm-associated urinary tract infections through assaying the anti-biofilm ability of lactic acid bacteria (LAB) against multidrug-resistant (MDR) uropathogens. Twenty LAB were obtained from pickles and fermented dairy products, and screened for their anti-biofilm and antimicrobial effects against MDR Escherichia coli U12 (ECU12). Lactobacillus plantarum Y3 (LPY3) (MT498405), showed the highest inhibitory effect and biofilm production. Pre-coating of a microtitre plate with LPY3 culture was more potent than co-incubation. Pre-coating with LPY3 culture generated a higher anti-biofilm effect with an adherence of 14.5% than cell free supernatant (CFS) (31.2%). Anti-biofilm effect of CFS was heat stable up to 100 °C with higher effect at pH 4–6. Pre-coating urinary catheter with LPY3 culture reduced the CFU/cm2 of ECU12 attached to the catheter for up to seven days. Meanwhile, CFS reduced the ECU12 CFU/cm2 for up to four days. Scanning electron microscope confirmed the reduction of ECU12 adherence to catheters after treatment with CFS. Therefore, Lactobacillus plantarum can be applied in medical devices as prophylactic agent and as a natural biointervention to treat urinary tract infections.

Mitigation of marine toxins by interactions with bacteria: The case of okadaic acid and tetrodotoxin

Harmful algal bloom and marine toxins are actual and overgrowing problems. Okadaic acid (OA) is the main toxin responsible for diarrheic shellfish poisoning in humans, while Tetrodotoxin (TTX) is a tremendously strong neurotoxin. Given their high toxicity, strategies to obtain a mitigation of these toxins are every day more fundamental, in the optic of preserve consumer health, and in giving supports to shellfisheries in selling their products. In this context, the ability of lactic acid bacteria (LAB) and Paracoccus spp. to reduce OA and TTX in vitro was evaluated using HPLC/MS-MS technique. Different mechanisms of interaction were observed. Some species of LAB were able to reduce significantly the amount of toxin while in viable state ( Lacticaseibacillus rhamnosus 1473 = 30% OA reduction), but also a binding effect of the toxins was observed. Contrarily, Paracoccus spp. was able to reduce significantly the amount of toxin while in a cell-free extract form, in particular Paracoccus aerius 5038 could reduce the presence of TTX of about 24%. This study provided a sound line of evidence for the possible future use of either specific bacteria or selected bacterial components to reduce the level of harmful marine toxins in aquaculture and food production. • Bonding effect of lactic acid bacteria with marine toxins was observed. • Metabolically active lactic acid bacteria significantly reduced the amount of toxins. • Cell-free extracts of Paracoccus strains reduced toxins' concentration.

Bio-Control Ability of Lactic Acid Bacteria and Bifidobacteria Against Ochratoxin a During Grape Juice Fermentation

Bio-Control Ability of Lactic Acid Bacteria and Bifidobacteria Against Ochratoxin a During Grape Juice Fermentation

Use of scanning electron microscopy and high-performance liquid chromatography to assess the ability of microorganisms to bind aflatoxin M1 in Minas Frescal cheese

The aim of this study was to evaluate the capacity of two strains of lactic acid bacteria (LAB), Lactobacillus rhamnosus and Lactococcus lactis, and a yeast strain, Saccharomyces cerevisiae, inactivated by heat (121 °C, 10 min), from binding to aflatoxin M1 (AFM1), as well as the interaction between these microorganisms, aflatoxin M1 and the Minas Frescal cheese matrix after 2 and 30 days of storage. The ability of LABs and S. cerevisiae to bind AFM1 to Minas Frescal cheese was evaluated by high performance liquid chromatography (HPLC) composed of a fluorescence detector. The interaction between these microorganisms and AFM1 was evaluated using a scanning electron microscope composed of a backscattered electron detector with a voltage of 15 kV and magnifications of 1000 ×, 5000 × and 8000 ×. The use of microorganisms as a biological method is efficient in reducing AFM1 in Minas Frescal cheese and does not affect the microbiological parameters. AFM1 reduction varied according to the microorganism used in the treatments. S cerevisiae showed greater capacity to bind AFM1 over time, compared to LABs. Scanning electron microscopy was especially useful, confirming that lactic acid bacteria and S. cerevisae were able to bind AFM1 particles in Minas Frescal cheese.

Capabilities of Bio-Binding, Antioxidant and Intestinal Environmental Repair Jointly Determine the Ability of Lactic Acid Bacteria to Mitigate Perfluorooctane Sulfonate Toxicity

Capabilities of Bio-Binding, Antioxidant and Intestinal Environmental Repair Jointly Determine the Ability of Lactic Acid Bacteria to Mitigate Perfluorooctane Sulfonate Toxicity

IN VITRO ASSESSMENT OF THE ADHESION ABILITY OF LACTIC ACID BACTERIA AND BIFIDOBACTERIA

The method for determining the adhesion and formation of biofilms under controlled conditions is optimized. The ability of lactic acid bacteria and bifidobacteria to adhere was evaluated. High adhesive activity was established in bacteria of the genera Lactobacillus and Bifidobacterium – from the studied strains, adhesion is characterized as “intense” in 31 and 38 %, respectively. Of the studied bifidobacteria, the strains belonging to the species B. adolescentis have the most pronounced ability to adhere.

Changes in the Folate Content and Fatty Acid Profile in Fermented Milk Produced with Different Starter Cultures during Storage.

The application of bacterial cultures in food fermentation is a novel strategy to increase the “natural” levels of bioactive compounds. The unique ability of lactic acid bacteria (LAB) to produce folate, B vitamins, and conjugated linolenic acid cis9trans11 C18:2 (CLA) during cold storage up to 21 days was studied. Although some species of LAB can produce folates and other important nutrients, little is known about the production ability of yogurt starter cultures. Pasteurized milk samples were inoculated with four different combinations of commercially available yogurt vaccines, including starter cultures of Bifidobacterium bifidum. Both the type of vaccine and the time of storage at 8 °C had a significant effect on the folate and CLA contents in the tested fermented milks. The highest folate content (105.4 µg/kg) was found in fresh fermented milk inoculated with Lactobacillus delbrueckii, Streptococcus thermophilus, and Bifidobacterium bifidum. Only the mix of Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus thermophilus, and Bifidobacterium bifidum showed potential (59% increase) to synthesize folate during seven days of storage. A significant increase in the content of CLA, when compared to fresh fermented milk, was observed during cold storage for up to 21 days in products enriched with Bifidobacterium bifidum.

Physiological, Morphological and Antioxidant Responses of Pediococcus pentosaceus R1 and Lactobacillus fermentum R6 Isolated from Harbin Dry Sausages to Oxidative Stress.

As functional starter cultures and potential probiotics, the ability of lactic acid bacteria to resist oxidative stress is essential to maintain viability and functional properties. This study investigates the effects of H2O2 at different concentrations (0, 1, 2, and 3 mM) on the physiological, morphological, and antioxidant properties of Pediococcus pentosaceus R1 and Lactobacillus fermentum R6 isolated from Harbin dry sausages. The increase in H2O2 concentration induced a significant increase in reactive oxygen species and a decrease in intracellular ATP levels (p < 0.05). Based on scanning electron microscopy, transmission electron microscopy, and electric conductivity analysis, H2O2 stress caused cell deformation, the destruction of cell membrane integrity, partial loss of the cytoplasm, and an increase in the cell conductivity of both strains. H2O2 stress with 1 mM or 2 mM concentrations could effectively improve the scavenging rates of free radicals, the activities of superoxide dismutase and glutathione peroxide, and the total antioxidant capacity of both strains (p < 0.05). In conclusion, an appropriate oxidative stress contributed to the activation of the antioxidant defense system of both strains, conferred strains a better effect in inhibiting the oxidation of fermented foods, and improved the health of the host.

Study of Beer Spoilage Lactobacillus nagelii Harboring Hop Resistance Gene horA

Lactic acid bacteria (LAB) cause the majority of beer spoilage incidents in the brewing industry. Previous studies revealed that the hop resistance genes, horA and horC, are applicable to the species-independent determination of beer spoilage ability of LAB. However, novel beer spoilage LAB species are occasionally emerging, and their insights should be shared in the industry to prevent spoilage incidents by these unknown species. In this study, Lactobacillus nagelii ABBC668 strain, isolated from spoiled pilsner-type beer, was investigated, as L. nagelii has been poorly characterized as a beer spoiler. The beer spoilage ability and hop resistance genes of L. nagelii ABBC668 were examined. Results showed that L. nagelii ABBC668 harbored hop resistance gene horA and exhibited beer spoilage ability. Also, it was considered that horA harbored by ABBC668 was acquired via horizontal gene transfer and had an unstable nature compared to that of Lactobacillus brevis. The unstable nature may account for the less frequent encounter of beer spoilage L. nagelii strains in the brewing industry. Furthermore, ABBC668 showed similar motility to other L. nagelii strains. To our knowledge, this is the first report of L. nagelii as a beer spoilage species.

KEMAMPUAN BAKTERI ASAM LAKTAT DALAM MENGHAMBAT Salmonella thypii

Lactic acid bacteria are known to have the ability to produce antimicrobial compounds known as bacteriocins. This study aims to determine the ability of lactic acid bacteria to inhibit the growth of Salmonella thypii bacteria. In this study, the lactic acid bacteria used were a collection of the Biology Laboratory of the University of Medan Area. Eight types of lactic acid bacterial isolates were used, including IN01, IN02, SF01, SF02, NN01, NN02 SPU01 and SPU04. A confirmation test was carried out on the growth of lactic acid bacteria and Salmonella thypii by visual and microcopic confirmation through differential staining. The results showed that all lactic acid bacteria were a group of gram-positive bacteria in the form of bacilli. The survival of lactic acid bacterial isolates in the environment with variations in pH and salt levels was indicated by the number of colonies that grew after the incubation period. The antagonistic ability of lactic acid bacteria in suppressing pathogenic bacteria was proven by the presence of an inhibition zone in the form of a clean area around the pathogenic colony. It is known that the SPU01 and SF01 bacterial isolates have the highest inhibition zone values, namely 29.79 mm and 28.13 mm.

Isolation of the Cholesterol-Assimilating Strain Pediococcus acidilactici LRCC5307 and Production of Low-Cholesterol Butter.

The objective of the present study was to evaluate the cholesterol-assimilation ability of lactic acid bacteria (LAB), which were isolated from kimchi, a Korean traditional fermented cabbage. The isolated strain, using modified MRS medium, showed 30.5% cholesterol assimilation activity and was named Pediococcus acidilactici LRCC5307. Types and concentrations of bile were investigated for their effects on increasing the cholesterol assimilation ability of the LRCC5307 strain, a 74.5% decrease in cholesterol was observed when 0.2% bile salts were added. In addition, the manufacture of low-cholesterol butter using LRCC5307 was examined. After fermentation, LRCC5307 with butter showed 8.74 Log CFU/g viable cells, pH 5.43, and a 11% decrease in cholesterol. These results suggest that LRCC5307 could help in the production of healthier butter by decreasing cholesterol and including living LAB.

Isolation of the cholesterol-assimilating strain Pediococcus acidilactici LRCC5307 and production of low-cholesterol butter

The objective of the present study was to evaluate the cholesterol-assimilation ability of lactic acid bacteria (LAB), which were isolated from kimchi, a Korean traditional fermented cabbage. The isolated strain, using modified MRS medium, showed 30.5% cholesterol assimilation activity and was named Pediococcus acidilactici LRCC5307. Types and concentrations of bile were investigated for their effects on increasing the cholesterol assimilation ability of the LRCC5307 strain, a 74.5% decrease in cholesterol was observed when 0.2% bile salts were added. In addition, the manufacture of low-cholesterol butter using LRCC5307 was examined. After fermentation, LRCC5307 with butter showed 8.74 Log CFU/g viable cells, pH 5.43, and a 11% decrease in cholesterol. These results suggest that LRCC5307 could help in the production of healthier butter by decreasing cholesterol and including living LAB.

Controlling the Risk of Bacillus in Food Using Berries

Introduction: Increasing the shelf life of foods without the addition of synthetic additives is a demand from both producers and consumers. Spore-forming bacteria are a problem in the food industry. To reduce their impact, it is necessary to use complex technologies, as well as ingredients with antibacterial or antibiotic properties. The aim of this study was to develop initial symbiotic combinations between lactic acid bacteria and berries to control food quality. The relevant ability of lactic acid bacteria in the presence of berry additives to inhibit the growth of Bacillus strains that degrade bakery products and dairy products was investigated. The antibacterial effect of berries on the growth of Bacillus mesentericus was studied. Methods: In this study was used inhibition zone test, also called Kirby-Bauer Test. The growth rate of bacteria was based on the measurement of the optical density at 600 nm (OD600). The method of Thompson et al. has been used to research the development of ropiness disease in wheat bread samples. Results: The diameter of the Bacillus pumilus growth inhibition zones under the berries action was as follows: aronia -18.0 ± 0.6 mm; raspberry -16.0 ± 0.4 mm; strawberry -15.0 ± 0.5 mm. Lactic bacteria in the presence of berry additives showed a growth rate, measured by optical density (OD) at 600 from 0.073 to 0.651 (for aronia) from 0.071 to 0.609 (for raspberries), from 0.073 to 0.597 compared to the increase in environments without added fruit, which amounted to -0.050 to 0.410. In the yogurt with added fruit, a synergism was formed with Streptococcus thermophilus, Lactobacillus delbrueckii subsp. Bulgaricus, Lactococcus lactis subsp Lactis biovar diacetilactis. The influence of fat-soluble extracts of sea buckthorn, rose-hip, and hawthorn fruits on the development of ropiness disease when storing wheat bread was investigated. The general Pearson coefficient (microbial count and pH) for all fruit yogurt samples is 0.95066. Conclusion: The combined use of lactic acid bacteria and berries (aronia, raspberry and strawberry) had a synergistic effect on the risk posed by Bacillus bacteria. 1% of fat-soluble extract from the vegetable matter reduced the risk of ropiness disease in wheat bread. This is due to the cumulative effect of the berries chemical composition (antioxidants, organic acids, etc.), increased acidity, lowered pH, and water activity of the food environment, below the development values of Bacillus.

Aflatoxin B1 and Sterigmatocystin Binding Potential of Non-Lactobacillus LAB Strains.

Research on the ability of lactic acid bacteria (LAB) to bind aflatoxin B1 (AFB1) has mostly been focusing on lactobacilli and bifidobacteria. In this study, the AFB1 binding capacities of 20 Enterococcus strains belonging to E. casseliflavus, E. faecalis, E. faecium, E. hirae, E. lactis, and E. mundtii, 24 Pediococcus strains belonging to species P. acidilactici, P. lolii, P. pentosaceus, and P. stilesii, one strain of Lactococcus formosensis and L. garviae, and 3 strains of Weissella soli were investigated in MRS broth at 37 °C at 0.2 µg/mL mycotoxin concentration. According to our results, among non-lactobacilli LAB, the genera with the best AFB1 binding abilities were genus Pediococcus, with a maximum binding percentage of 7.6% by P. acidilactici OR83, followed by genus Lactococcus. For AFB1 bio-detoxification purposes, beside lactobacilli, pediococci can also be chosen, but it is important to select a strain with better binding properties than the average value of its genus. Five Pediococcus strains have been selected to compare their sterigmatocystin (ST) binding abilities to AFB1 binding, and a 2–3-fold difference was obtained similar to previous findings for lactobacilli. The best strain was P. acidilactici OR83 with 18% ST binding capacity. This is the first report on ST binding capabilities of non-Lactobacillus LAB strains.

Effects of probiotic bacteria of Lactobacillus acidophilus and Lactobacillus casei on aflatoxin B1 detoxification within a simulated gastrointestinal tract model

The present study was objected to assess the ability of lactic acid bacteria in the reduction of aflatoxin B1 (AFB1) in a simulated human gastrointestinal tract. In this work, eight treatments were prepared to compare the ability of noted probiotic bacteria in AFB1 reduction in different simulated gastrointestinal conditions. The results of the present study revealed a significant reduction in AFB1 in all of the treatments in which the highest reduction rate was observed by L. acidophilus in the absence of sterilized milk. Moreover, the findings showed that bacteria, gastric juice, and small intestine may contribute to the reduction of AFB1.

Isolation and characterization of an Enterococcus strain from Chinese sauerkraut with potential for lead removal

Traditional fermented foods are important sources of probiotics, which attract intensive attentions because of their beneficial effects. The potential of probiotic strains to remove heavy metals have also aroused interest from researchers. In this study, the ability of lactic acid bacteria (LAB) isolated from various fermented foods to removal lead (Pb) was tested, and strains with high removal efficiency were selected and characterized by the use of scanning electron microscope equipped with energy dispersive spectrometer (SEM–EDS), Fourier transform infrared spectrometer (FTIR) and X-ray photoelectron spectroscopy (XPS) to investigate the mechanism of lead removal. Two selected strains, identified as Enterococcus faecium DUTYH_16120012 and Enterococcus sp. DUTYH_16120026, were found capable of removing Pb2+ efficiently from MRS broth. Results indicated that initial pH, Pb2+ concentration and growing temperature were important factors affecting lead removal, which might be attributed to the effects of these factors on bacterial growth and physiology. The cell wall played a major role, contributing 80.58 ± 1.65%, in Pb2+ removal by bacterial cells. SEM–EDS and XPS analysis implied that possible chemical compositions of the yellow–brown deposits observed on the cell pellets grown in presence of lead were PbO2 and PbO. FTIR analysis indicated that some functional groups (–OH, –C=O, –N–H, –C–N) were involved in the Pb2+ removal process. The isolated strains demonstrated a potential for lead removal, but further study was needed to reveal the detailed mechanism by which the selected strain removes lead from the growing environment.

Characterization of Probiotics Isolated from Intestine of Mackerel Fish (Rastrelliger sp.) from Lembata Regency of East Nusa Tenggara

The research aimed to isolate, characterize, and analyze the ability of lactic acid bacteria (LAB) potential as probiotics to produce hydrolase enzyme. The LAB was isolated using MRS agar by the spread plate method. The LAB characterization includes antimicrobial activity, tolerance to low pH, bile salt, salinity, autoaggregation properties, and ability to produce hydrolytic enzymes. The isolate which has the highest ability to inhibit Aeromonas hydrophila is KBP 3.3, while the isolate which inhibits the highest Streptococcus agalactiae is KBP 1.1.1. The KBP 3.3 and KBP 1.1.1 were able to survive at pH 1 for 24 hours with a survival rate of 93.6% and 98.3%. The KBP 3.3 and KBP 1.1.1 are tolerant to 7.5% bile salt concentrations for 24 hours of 99.46% and 99.11%. The KBP 3.3 is tolerant to 0.5 % salinity for 24 hours with the highest survival rate of 113.38%, while KBP 1.1.1 is 94%. The KBP 3.3 and 1.1.1 have autoaggregation properties of 92.18% and 87.84%. The KBP 3.3 produced the highest lipase enzyme, while KBP 1.1.1 produced the protease enzyme.Keywords: hydrolytic enzyme, lactic acid bacteria, mackerel, probiotic

Evaluation of the Immunomodulatory Ability of Lactic Acid Bacteria Isolated from Feedlot Cattle Against Mastitis Using a Bovine Mammary Epithelial Cells In Vitro Assay.

Bovine mastitis, the inflammation of the mammary gland, affects the quality and quantity of milk yield. Mastitis control relies on single or multiple combinations of antibiotic therapy. Due to increasing antibiotic resistance in pathogens, the intramammary infusion of lactic acid bacteria (LAB) has been considered as a potential alternative to antibiotics for treating and preventing bovine mastitis through the improvement of the host immunity. Probiotic effects are a strain-dependent characteristic; therefore, candidate LAB strains have to be evaluated efficiently to find out the ones with the best potential. Here, we investigated LAB strains originally isolated from feedlot cattle’s environment regarding their ability in inducing the Toll-like receptor (TLR)-triggered inflammatory responses in bovine mammary epithelial (BME) cells in vitro. The BME cells were pre-stimulated with the LAB strains individually for 12, 24, and 48 h and then challenged with Escherichia coli-derived lipopolysaccharide (LPS) for 12 h. The mRNA expression of selected immune genes—interleukin 1 alpha (IL-1α), IL-1β, monocyte chemotactic protein 1 (MCP-1), IL-8, chemokine (C-X-C motif) ligand 2 (CXCL2), and CXCL3 were quantified by real-time quantitative PCR (RT-qPCR). Results indicated that pretreatment with some Lactobacillus strains were able to differentially regulate the LPS inflammatory response in BME cells; however, strain-dependent differences were found. The most remarkable effects were found for Lactobacillus acidophilus CRL2074, which reduced the expression of IL-1α, IL-1β, MCP-1, IL-8, and CXCL3, whereas Lactobacillus rhamnosus CRL2084 diminished IL-1β, MCP-1, and IL-8 expression. The pre-stimulation of BME cells with the CRL2074 strain resulted in the upregulated expression of three negative regulators of the TLRs, including the ubiquitin-editing enzyme A20 (also called tumor necrosis factor alpha-induced protein 3, TNFAIP3), single immunoglobin IL-1 single receptor (SIGIRR), and Toll interacting protein (Tollip) after the LPS challenge. The CRL2084 pre-stimulation upregulated only Tollip expression. Our results demonstrated that the L. acidophilus CRL2074 strain possess remarkable immunomodulatory abilities against LPS-induced inflammation in BME cells. This Lactobacillus strain could be used as candidate for in vivo testing due to its beneficial effects in bovine mastitis through intramammary infusion. Our findings also suggest that the BME cells immunoassay system could be of value for the in vitro evaluation of the immunomodulatory abilities of LAB against the inflammation resulting from the intramammary infection with mastitis-related pathogens.

The importance of the S-layer on the adhesion and aggregation ability of Lactic acid bacteria.

S-layer proteins in Lactic acid bacteria are not the only cell surface structures used for aggregation, but also plays significant role for intestinal tissue adhesion along with some other functional elements. In addition, it was determined that the properties of S-layer proteins differs not only between species but also the strains which belong to same species. In this work, presence and some functions of S-layer in lactic acid bacteria were determined, its effect on resistance to gastrointestinal enzymes, aggregation and adhesion ability were investigated as well. For this purpose S-layers of microorganisms were removed by 5M LiCl treatment and size of the proteins were determined by SDS-PAGE analysis. The removal of S-layer proteins caused a change in the resistance of microorganisms to GIS enzymes. After the S-layer removal, two strains considerably lost their resistance to GIS enzymes. The strains mostly lost their aggregation ability in the absence of S-layer. The results showed that S-layer proteins are not the only structures involved in aggregation processes but, is a major mediator in Lactobacilli. Removal of S-layer had no effect on adhesion ability of W. cibaria DA28, the effect on L. casei DA4, L. coryniformis DA263 and L. plantarum DA140 was moderate, but the effect was high on L. plantarum DA100. The study showed that S-layer proteins play limited protection against GIS enzymes. In addition, absence of S-layer adversely affected aggregation and adhesion ability of strains.