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Exopolysaccharides (EPSs) are novel functional additives for low-fat yogurt. Pharmaceutical, medical, and food industries are using more LAB-based EPSs. in this study, leuconostoc spp. was used to produce ninth bacterial ePSs in a modified molasses medium. Production of EPSs was concentration-dependent on all stains and the highest yield was obtained from the S3 strain (55.23 g/l), followed by S6 (49.95 g/l), S8 (45.68 g/l), and S7 (44.23), respectively. HPLC and FTIR analysis showed that all purified EPSs from leuconostoc citreum (S3) and leuconstoc holzaapfelii (S8) were related to exopolysaccharide glucan. Anticancer activity of all EPSs samples (EPSS1-9) against Caco-2 cells and normal MCR-5 cells were investigated using Mtt assay. the results revealed that Caco-2 cells were more sensitive than the normal MCR-5 cells. the highest anticancer activity against Caco-2 cancer cells was recorded for EPS8 (IC50 = 22.94 µg/ml, Si=3.73), followed by EPS3 (IC50 = 36.15 µg/ml, SI=8.72), ePS1 (IC50 = 50.01 µg/ml, SI=3.73), and EPS4 (IC50 = 94.90 µg/ml, SI=3.26), respectively. the lowest cytotoxicity was recorded for ePS5 (IC50 = 130.5 µg/ml). the most active ePSs (EPS3 and EPS8) were used as fat replacements and stabilizers in low-fat set yogurt at non-toxic concentrations (0.4, 0.8, and 1.2%). EPS3 and EPS8 improved the low-fat yogurt's organoleptic and rheological properties. ePS8 had the highest water holding capacity (77.26%), viscosity (3660 CP), and lowest syneresis (22.95%) and whey off (0.6 ml). low-fat set yogurt enhanced with EPS3 and EPS8 recorded the highest sensory evaluation values with overall acceptability, especially EPS3b, EPS3c, EPS8c, and EPS8b; the total score point of 97.50, 97.43, 96.51, and 96.36, respectively in fresh age compared to control yogurt (92.64). in conclusion, leuconostoc EPSs, especially EPS8, can be explored for anti-cancer effects on Caco-2 colorectal cancer cells. it could also improve the rheological and organoleptic qualities of low-fat set yogurt. [ABSTRACT FROM AUTHOR]

Exopolysaccharides (EPS) particularly, from Lactic acid bacteria have received increasing attention in food, medical, and pharmaceutical applications. The present work aims to isolate, characterize and identify exopoly saccharide-producing bacteria from fermented fruits and vegetables and dairy products. A total of 55 isolates were isolated from fermented fruits, vegetables, and dairy products depending on the mucoid appearance of the colonies. Based on total EPS production, the most promising nine strains were selected, phenotypically and genotypically characterized. They were facultative anaerobe, arranged in pairs/chains (cocco bacillus), oxidase, and catalase-negative, non-spore forming and non-motile Gram-positive bacteria. All the strains were capable of growing at optimum pH between 5-7, tolerate to NaCl up to 7% (w/v), growing at 20-37°C with optimum growth at 30°C, no growth was observed at 45°C. In addition they could utilize small range of organic compounds, except isolate S1 was differ from the others by their ability to utilize a varied range of organic compounds. Construction of phylogenetic tree, on the basis of partial 16S rRNA gene sequences indicated that isolate S1 was similar to Leuconostoc citreum with similarity of 91.3%, while, isolates S2 and S3 were similar to Leu. fallax and Leu. mesenteroides with similarity of 99.40 % and 97.73%, respectively. Isolates S4, S5, S7, S8, and S9 were similar to Leu. holzaapfelii with similarity of 98.3, 98.7 and 99.8, 98.5 and 98.1, respectively, while isolate S6 was similar to Leu. lactis with similarity of 97.9%. None of sugars such as lactose, glucose, and fructose except sucrose were support EPS production from these strains. The highest yield of EPS was recorded for isolates S6, S1 and S7 which were 61.90, 61.80 and 60 gl-1, respectively, followed by isolates S4, S9, S5 and S8 which were 58.40, 53.06, 51.61 and 33.53 gl-1, respectively. Although, the lowest yield was observed for the isolates S3 and S2 which were 22.08 and 18.80 g l-1, respectively. Finally, it could be concluded that EPS production from these strains in the current study, considering them to be the alternative choice for enhancing production of EPS with increased yields, with promising realistic importance in food, pharmaceutical, as well as dairy industries. [ABSTRACT FROM AUTHOR]

In this study, 120 lactic acid bacterial strains from different fermented dairy products as well as 10 bacterial intestinal isolates were evaluated for in vitro and in vivo degradation of various food azo dyes. Of these isolates, lactic acid bacteria (LAB) strains 13 and 100 and the intestinal isolates Ent2 and Eco5 exhibited 96–98% degradation of the tested food azo dyes within 5–6 hours. High performance liquid chromatography mass spectra of sunset yellow (E110) and carmoisine (E122) anaerobic degradation products by the intestinal isolates showed that they were structurally related to toxic aromatic amines. For an in vivo study, eight groups of rats were treated for 90 days with either the food azo dyes or their degradation products. All groups were kept for a further 30 days as recovery period and then dissected at 120 days. Hematological, histopathological, and protein markers were assessed. Rats treated with either E110/E122 or their degradation products exhibited highly significant changes in red blood cell count, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and white blood cell count. In addition, alanine and aspartate aminotransferases, amylase, total bilirubin, blood urea nitrogen, creatinine, glucose, total protein, and globulins were significantly increased. Furthermore, marked histopathological alterations in the liver, kidney, spleen, and small intestine were observed. Significant decreases in inflammation and a noticeable improvement in the liver, kidney, spleen, and small intestine of rats treated with LAB and food azo dyes simultaneously were observed. Finally, these results provide a reliable basis for not only a better understanding of the histological and biochemical effects of food additives, but also for early diagnostics. In addition, LAB strains 13 and 100 may play an important role as potential probiotics in food and dairy technology as a probiotic lactic acid starter. [ABSTRACT FROM AUTHOR]

This study investigated different amino acid-based surfactants (AASs), also known as biosurfactants, including sodium N-dodecyl asparagine (AS), sodium N-dodecyl tryptophan (TS), and sodium N-dodecyl histidine (HS) for their potential anticorrosion, antibacterial, and antidermatophyte properties. The chemical and electrochemical techniques were employed to examine the copper corrosion inhibition efficacy in H2SO4 (1.0 M) solution at 298 K. The results indicated their promising corrosion inhibition efficiencies (% IEs), which varied with the biosurfactant structures and concentrations, and the concentrations of corrosive medium. Higher % IEs values were attributed to the surfactant adsorption on the copper surface and the production of a protective film. The adsorption was in agreement with Langmuir adsorption isotherm. The kinetics and mechanisms of copper corrosion and its inhibition by the examined AASs were illuminated. The surfactants behaved as mixed-kind inhibitors with minor anodic priority. The values of % IEs gained from weight loss technique at a 500 ppm of the tested surfactants were set to be 81, 83 and 88 for AS, HS and TS, respectively. The values of % IEs acquired from all the applied techniques were almost consistent which were increased in the order: TS > HS ≥ AS, establishing the validity of this study. These surfactants also exhibited strong broad-spectrum activities against pathogenic Gram-negative and Gram-positive bacteria and dermatophytes. HS exhibited the highest antimicrobial activity followed by TS, and AS. The sensitivity of pathogenic bacteria varied against tested AASs. Shigella dysenteriae and Trichophyton mantigrophytes were found to be the most sensitive pathogens. HS exhibited the highest antibacterial activity against Shigella dysenteriae, Bacillus cereus, E. coli, K. pneumoniae, and S. aureus through the formation of clear zones of 70, 50, 40, 39, and 35 mm diameters, respectively.AASs also exhibited strong antifungal activity against all the tested dermatophyte molds and fungi. HS caused the inhibition zones of 62, 57, 56, 48, and 36 mm diameters against Trichophyton mantigrophytes, Trichophyton rubrum, Candida albicans, Trichosporon cataneum, and Cryptococcus neoformans, respectively. AASs minimal lethal concentrations ranged between 16 to 128 µg/ml. HS presented the lowest value (16 µg/ml) against tested pathogens followed by TS (64 µg/ml), and AS (128 µg/ml). Therefore, AASs, especially HS, could serve as an effective alternative antimicrobial agent against food-borne pathogenic bacteria and skin infections-associated dermatophyte fungi. [ABSTRACT FROM AUTHOR]

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper. [ABSTRACT FROM AUTHOR]