High Bile Salt Research Articles

E. coli Nissle microencapsulation in alginate-chitosan nanoparticles and its effect on Campylobacter jejuni in vitro

Microencapsulation enhances the oral delivery of probiotic bacteria. In this study, the probiotic Escherichia coli Nissle 1917 (EcN) was microencapsulated using alginate and chitosan nanoparticles. The result showed 90% encapsulation yield of EcN, and the encapsulated EcN displayed significantly (P < 0.05) increased survival in low pH (1.5), high bile salt concentration (4%), and high temperature (70°C). The most effective cryopreservatives of EcN during freezing and thawing was skim milk and sucrose. Exposure to microencapsulated EcN significantly (P < 0.05) reduced the Campylobacter jejuni growth by 2 log CFU. The rate of EcN release from microcapsule was 9.2 × 105cellmin-1, and the appropriate model to describe its release kinetics was zero order. Importantly, the entrapment of EcN inside the microcapsule did not eliminate the exterior diffusion of EcN produced antioxidant compounds. In addition, the EcN microcapsule efficiently adhered to intestinal HT-29 cells and the pre-treatment of HT-29 cells with EcN-microcapsule for 4h significantly (P < 0.05) reduced the invasion (1.9 log) of C. jejuni; whereas, completely abolished the intracellular survival. Furthermore, HT-29 cells pre-treated with encapsulated EcN in PCR array showed decreased expression (> 1.5-fold) of genes encoding chemokines, toll-like receptors, interleukins, and tumor necrosis factors. In conclusion, the alginate-chitosan microcapsule can provide effectual platform to deliver probiotic EcN and thereby can reduce the Campylobacter infection in chickens and humans.

Identification and characterization of probiotic yeast isolated from digestive tract of ducks.

The objective of this study was to isolate and identify yeast strains from the digestive tract of ducks, and evaluate in vitro their potential as probiotics in poultry. The yeast strains were isolated using malt extract agar medium, and identified through morphological, physiological, and biochemical tests as well as sequence homology analyses of 26S rDNA D1/D2 region. A total of 35 yeast strains were isolated from the guts of Cherry Valley meat ducks, including seven strains of Saccharomyces cerevisiae (S. cerevisiae). These seven strains of S. cerevisiae were further screened for their use as alternative yeast probiotics strains for poultry feed. The yeast strains were characterized for their cell surface hydrophobicity, autoaggregation ability, and resistance to high temperature (30°C, 37°C, and 42°C), low pH (2.0, 3.0, and 4.0), bile salts (0.3% and 0.6%), and nutrition starvation (2, 4, 6, 8, 10, and 12 days). The isolates of WHY-2 and WHY-7 had a higher survival percentage at 37°C, pH 2.0, 0.60% poultry bile salts, and 10 days of nutrition starvation, with higher cell surface hydrophobicity and autoaggregation, when compared with the other isolates, suggesting that the isolates WHY-2 and WHY-7, could be used as probiotic candidates. The data obtained in this study could help in selecting probiotic yeast candidates for use in poultry industry.

Research on Lipid-lowing Capability of Three Edible Streptococcus from Yogurt in Vitro

Three common edible streptococcus thermophilus (St)、 streptococcus lactis (L1) and streptococcus cremoris (L2) from yogurt were used to investigate the activity of reducing lipid in vitro. All of the three streptococcus could tolerate adverse effects by low acid and high bile salts to survival and reproduction. St had the strongest tolerance with artificial gastric juice and 0.3% porcine bile salt, and still alive 5.02×106 CFU/mL. The rates of degrading triglyceride and triglyceride of St were up to 70% and 50%, which were also the best of the three. Next was L1, it could degrade more than 70% cholesterol and 48% triglyceride. And the rates of degrading triglyceride and triglyceride of L2 were 10-20%.

Molecular and in vitro assessment of some probiotic characteristics of amylolytic Lactobacillus plantarum strains from Bulgarian fermented products.

In the recent years, consumers' interest in healthy diet opened a new field for functional food development through combining the valuable composition of cereals and the health-promoting properties of lactic acid bacteria (LAB). LAB with amylolytic properties can assimilate starch in a single-step process and could be successfully applied as starter cultures offering an efficient nutritional conversion of cereal matrices. The probiotic potential of amylolytic LAB has not been investigated so far, therefore the present study focused on the molecular screening and in vitro tests of five amylolytic Lactobacillus plantarum strains to assess their tolerance to high acid and bile salts concentrations and antibiotic resistance as basic characteristics required for probiotic strains selection. Results showed excellent correspondence between the genetic screening and the phenotypic tests performed. Survivability at high acidity and bile salts presence was strain specific, with significant positive effect observed for cultures in stationary phase compared to those in exponential phase. Effect of starch in the medium proved most important to ensure viability of the amylolytic strains, which reveals the excellent potential of amylolytic LAB for commercially relevant probiotic applications. The strains proved to be generally safe in terms of antibiotic resistance. Among the five tested strains, L. plantarum Bom2 showed the best probiotic potential.

Na+‐taurocholate cotransporting polypeptide inhibition has hepatoprotective effects in cholestasis in mice

Accumulation of bile salts (BSs) during cholestasis leads to hepatic and biliary injury, driving inflammatory and fibrotic processes. The Na+‐Taurocholate Cotransporting Polypeptide (NTCP) is the major hepatic uptake transporter of BSs, and can be specifically inhibited by myrcludex B. We hypothesized that inhibition of NTCP dampens cholestatic liver injury. Acute cholestasis was induced in mice by a 3.5‐diethoxycarbonyl‐1.4‐dihydrocollidine (DDC) diet or by bile duct ligation (BDL). Chronic cholestasis was investigated in Atp8b1‐G308V and Abcb4/Mdr2 deficient mice. Mice were injected daily with myrcludex B or vehicle. Myrcludex B reduced plasma alkaline phosphatase (ALP) levels in DDC‐fed, Atp8b1‐G308V and BDL mice by 39%, 27% and 48% respectively. Expression of genes involved in fibrosis, proliferation and inflammation was reduced by myrcludex B treatment in DDC‐fed and Atp8b1‐G308V mice. NTCP‐inhibition increased plasma BS levels from 604±277 to 1746±719 μm in DDC‐fed mice, 432±280 to 762±288 μm in Atp8b1‐G308V mice and from 522±130 to 3625±378 μm in BDL mice. NTCP‐inhibition strongly aggravated weight loss in BDL mice, but not in other cholestatic models studied. NTCP‐inhibition reduced biliary BS output in DDC‐fed and Atp8b1‐G308V mice by ∼50% while phospholipid (PL) output was maintained, resulting in a higher PL/BS ratio. Conversely, liver injury in Abcb4 deficient mice, lacking biliary phospholipid output, was aggravated after myrcludex B treatment. Conclusion: NTCP‐inhibition by myrcludex B has hepatoprotective effects, by reducing BS load in hepatocytes and increasing the biliary PL/BS ratio. High micromolar plasma BS levels after NTCP‐inhibition were well tolerated. NTCP‐inhibition may be beneficial in selected forms of cholestasis. (Hepatology 2018).

Safety, potential biotechnological and probiotic properties of bacteriocinogenic Enterococcus lactis strains isolated from raw shrimps

The aims of this study are to isolate new bacteriocinogenic lactic acid bacterial strains from white (Penaeus vannamei) and pink (Palaemon serratus) raw shrimps and evaluate their technological and probiotic potentialities. Seven strains were selected, among fifty active isolates, as producing interesting antimicrobial activity. Identified as Enterococcus lactis, these isolates were able to produce enterocins A, B and/or P. The safety aspect, assessed by microbiological and molecular tests, demonstrated that the strains were susceptible to relevant antibiotics such as vancomycin, negative for haemolysin and gelatinase activities, and did not harbour virulence and antibiotic resistance genes. The assessment of potential probiotic and technological properties showed a low or no lipolytic activity, moderate milk-acidifying ability, high reducing power, proteolytic activity and tolerance to bile (P < 0.05) and good autoaggregation and coaggregation capacities. Two strains designated as CQ and C43 exhibiting high enzymatic activities and bile salt hydrolase activity were found to display high survival under simulated in vitro oral cavity and gastrointestinal tract conditions caused by presence of lysozyme, pepsin, pancreatin, bile salts and acidic pH. This study highlights safe Enterococcus lactis strains with great technological and probiotic potentials for future application as new starter, adjunct, protective or probiotic cultures in food industry.

Characterization and evaluation of lactic acid bacteria candidates for intestinal epithelial permeability and Salmonella Typhimurium colonization in neonatal turkey poults

The present study evaluated the microbiological properties of three probiotic candidate strains of lactic acid bacteria (LAB) (128; 131; CE11_2), their effect on intestinal epithelial permeability, and their ability to reduce intestinal colonization of Salmonella Typhimurium (ST) individually or as a batch culture in neonatal turkey poults. Isolates were characterized morphologically and identified using 16S rRNA sequence analyses. Each isolate was evaluated for tolerance and resistance to acidic pH, high osmotic NaCl concentrations, and bile salts in broth medium. In vitro assessment of antimicrobial activity against different enteropathogenic bacteria was determined using an overlay technique. In vitro intestinal permeability was evaluated using a stressed Caco-2 cell culture assay treated with/without the probiotic candidates. The in vivo effect of the selected LAB strains on ST cecal colonization was determined in two independent trials with neonatal turkey poults. The results obtained in this study demonstrate the tolerance of LAB candidates to pH 3, a NaCl concentration of 6.5%, and high bile salts (0.6%). All strains evaluated exhibited in vitro antibacterial activity against Salmonella Enteritidis, ST, and Campylobacter jejuni. Candidates 128 and 131 exhibited a coccus morphology and were identified as Enterococcus faecium, and bacterial strain CE11_2 exhibited clusters of cocci-shaped cells and was identified as Pediococcus parvulus. All three candidate probiotics significantly (P < 0.05) increased transepithelial electrical resistance (TEER) in Caco-2 cells following a 3-h incubation period with hydrogen peroxide compared to control and blank groups. The combination of all three candidates as a batch culture exhibited significant efficacy in controlling intestinal colonization of ST in neonatal turkey poults. Evaluation of the combination of these selected LAB strains according to performance and intestinal health parameters of chickens and turkeys are currently in process.

Investigation of Lactic Acid Bacteria Isolated from Giant Panda Feces for Potential Probiotics In Vitro.

The present study aimed to isolate an optimal lactic acid bacterial strain from the feces of healthy giant pandas. The strain exhibited good stability at low pH and high bile salt concentrations, activity against pathogens relevant to pandas, and antibiotic susceptibility. In the current study, 25 isolates were obtained from de Man, Rogosa, and Sharpe agar. Two (E21 and G83) and eight (E1, E2, E16, E18, E21, E69, E70, and G83) isolates demonstrated good performance at pH2.0 and bile 2% (w/v), respectively. Three isolates (G83, G88, and G90) possessed better antimicrobial effect on enterotoxigenic Escherichia coli CVCC196 (ETEC) than the rest. One isolate (G83) strongly affected Salmonella, whereas three (G83, G87, and G88) exhibited inhibitory activity against Staphylococcus aureus. All isolates were multi-drug resistant. These isolates were identified as Lactobacillus (5 isolates) and Enterococcus (20 isolates) by 16S rRNA sequencing. Virulence genes were detected in Enterococcus isolates. Isolate G83 was identified as Lactobacillus plantarum and was considered as the best probiotic candidate among all of the experimental isolates. This study provided necessary and important theoretical guidance for further experiments on G83 in vivo.

An in vivo assessment of the cholesterol-lowering efficacy of Lactobacillus plantarum ECGC 13110402 in normal to mildly hypercholesterolaemic adults.

Coronary heart disease (CHD) is one of the major causes of death and disability in industrialised countries, with elevated blood cholesterol an established risk factor. Total plasma cholesterol reduction in populations suffering from primary hypercholesterolemia may lower CHD incidence. This study investigated the cholesterol reducing capacity of Lactobacillus plantarum ECGC 13110402, a strain selected for its high bile salt hydrolase activity, in 49 normal to mildly hypercholesterolaemic adults. Primary efficacy outcomes included effect on blood lipids (total cholesterol (TC), low density lipoproteins (LDL-C), high density lipoproteins (HDL-C) and triacylgycerides (TAG), inflammatory biomarkers and occurrence/severity of gastrointestinal side effects to establish safety and tolerance of the intervention. Secondary outcomes included blood pressure, immune biomarkers, gut microbiota characterisation and metabonome changes. The study was run in a parallel, double blind, placebo controlled, randomised design in which the active group ingested 2x109 CFU encapsulated Lactobacillus plantarum ECGC 13110402 twice daily. Daily ingestion of the active treatment resulted in a statistically significant reduction in LDL-C in volunteers with baseline TC<5mM during the 0–12 week period (13.9%, P = 0.030), a significant reduction in TC in volunteers with baseline TC≥6mM in the 0–6 week period (37.6%, P = 0.045), a significant decrease in TAG (53.9% P = 0.030) and an increase in HDL-C (14.7%, P = 0.007) in the over 60 years population in the 6–12 week period. A statistically significant reduction in systolic blood pressure was also observed across the active study group in the 6-12-week period (6.6%, P = 0.003). No impact on gastrointestinal function and side effects was observed during the study. Similar to blood and urine metabonomic analyses, faecal metagenomics did not reveal significant changes upon active or placebo intake. The results of this study suggest that Lactobacillus plantarum ECGC 13110402 is a well-tolerated, natural probiotic, that may be used as an alternative or supplement to existing treatments to reduce cardiovascular risk.Trial registration: Clinical trials.gov NCT03263104

Indigenous Probiotic Lactobacillus Isolates Presenting Antibiotic like Activity against Human Pathogenic Bacteria.

Background: Indigenous lactic acid bacteria are well known probiotics having antibacterial activity against potentially pathogenic bacteria. This study aims to characterize the curd lactobacilli for their probiotic potentiality and antagonistic activity against clinical bacteria. Methods: Four curd samples were processed microbiologically for the isolation of lactic acid bacteria (LAB). The LAB strains obtained were identified by conventional methods: cultural aspect, gram-staining, biochemical and sugar fermentation tests. The probiotic properties were justified with tolerance to low-pH, bile salt and sodium chloride, and the antagonistic activity of the lactobacilli against human pathogenic bacteria (Escherichia coli, Proteus vulgaris, Acinetobacter baumannii and Salmonella enterica serovar Typhi) was assessed. Hemolytic activity and antibiotic susceptibility were determined for the lactobacilli isolates, and the cumulative probiotic potential (CPP) values were recorded. Result: Four lactobacilli isolates, L. animalis LMEM6, L. plantarum LMEM7, L. acidophilus LMEM8 and L. rhamnosus LMEM9, procured from the curd samples, survived in low-pH and high bile salt conditions, and showed growth inhibitory activity against the indicator bacteria by agar-well (zone diameter of inhibition; ZDIs: 13.67 ± 0.58–29.50 ± 2.10 mm) and agar overlay (ZDIs: 11.33 ± 0.58–35.67 ± 2.52 mm) methods; the average growth inhibitory activity of lactobacilli ranged 233.34 ± 45.54–280.56 ± 83.67 AU/mL, against the test bacterial pathogens. All the lactobacilli were non-hemolytic and sensitive to most of the test antibiotics. The CPP values of the isolated LAB were recorded as 80–100%. Conclusion: The curd lactobacilli procured might be used as the valid candidates of probiotics, and bio-therapeutics against bacterial infection to humans.

IN VITRO CHARACTERIZATION OF LACTIC ACID BACTERIA ISOLATED FROM LASODA BARI- A RARE FERMENTED FOOD OF HIMACHAL PRADESH-INDIA FOR POTENTIAL PROBIOTIC ATTRIBUTES

Probiotic lactic acid bacteria (LAB) are health promoting microorganisms which are recently been used as food additives and therapeutic supplements. Recently, there has been an increase of interest regarding the commercial utilization of probiotic LAB strains isolated from traditional and naturally fermented food products. Therefore, the present study was aimed to isolate and screen lactic acid bacteria from Lasoda bari – a rare fermented food of Himachal Pradesh, for the first time for their probiotic potential. Total eight isolates were obtained out of which one isolate was selected based on its broadest antagonistic spectrum. This strain was identified using 16S rRNA technique as Pediococcus pentosaceus LB-CC. The analysis of acid resistance, bile tolerance, antibiotic sensitivity, auto-aggregation and microbial adhesion to organic solvents were established. The results revealed normal growth of P. pentosaceus LB-CC in the presence of low pH, high bile salt concentration and ability to produce antimicrobial compounds. No gelatinase and DNase enzyme activity was detected. Natural susceptibility to the tested antibiotics was observed. Thus, according to these results, this probiotic strain could be proposed as safe potential probiotic culture and can be exploited for the production of nutraceutical agents.

Secretion metabolites of dairy Kluyveromyces marxianus AS41 isolated as probiotic, induces apoptosis in different human cancer cell lines and exhibit anti-pathogenic effects

This study aimed to the isolation, molecular identification, and probiotic characterization of yeasts from traditional Iranian dairy products as well the investigation of proapoptotic effects of yeasts secretion metabolites on different human epithelial cancer and normal cell lines. The expression levels of key genes in intrinsic/extrinsic apoptosis pathways were also studied. Based on prescreening tests, among all yeasts, K. marxianus AS41 showed the highest anticancer activity in AGS cells (53.8% mortality), high tolerance to low pH (71% survival rate) and high bile salt (83% survival rate) conditions, high anti-pathogenic activities, and susceptibility to conventional antifungal. Moreover, K. marxianus AS41 secretion metabolites, significantly downregulated Bcl-2 and upregulated BAD and CASP 9 gene expression in the AGS cancer cells compared to 5-Fluorouracil as positive control. Besides, in all epithelial cancer cells the expression level of Fas-R, CSAP 8 and CASP 3 upregulated significantly, suggested that extrinsic apoptosis pathway is the main path for apoptosis of malignant cells. Finally, K. marxianus AS41 isolated from dairy products can be introduced as probiotics and its secretion metabolites affect metabolic activity and exhibit proapoptotic activity on epithelial cancer cells with non-significant effect on normal cells suggesting that further studies are required to explain the exact mechanism of apoptosis induction by K. marxianus AS41 culture supernatant extracts.

Effect of encapsulant and cryoprotectant on the viability of probiotic Pediococcus acidilactici ATCC 8042 during freeze-drying and exposure to high acidity, bile salts and heat

Encapsulation and freeze drying are among the most preferable preservation methods due to their considerable effects on probiotics survival. The effects of different cryoprotectants on the viability of free cells during freeze drying and coating materials for encapsulation strategy have been investigated by various researchers. However, information on the effect of cryoprotectants on the viability of the encapsulated probiotics during freeze-drying seems scarce. In this study Pediococcus acidilactici ATCC 8042 was encapsulated using calcium-alginate (ALGsm-FD) and calcium-alginate co-coating with chitosan (CHsm-FD) via extrusion technique. They were subsequently freeze dried using 10% (w/w) skim milk as cryoprotectant. Immediately after the freeze drying, ALGsm-FD showed the highest survival (15.77%) compared to the CHsm-FD (0.36%), free cells protected with skim milk (FCsm-FD) (11.02%) and both encapsulated and free cell samples without the addition of skim milk (0%). Co-coating the entrapped cells in alginate bead with chitosan was only accommodating the cells survival during bile solution (pH = 8.25) treatment but not for freeze drying and gastric juice treatment (pH = 1.55). In comparison, ALGsm-FD and CHsm-FD were found to be more heat tolerance than FCsm-FD. The findings indicated that the supplementation of cryoprotectant conferred an important protective effect to either encapsulated or free probiotic cells during freeze drying.

Isolation, Identification and In vitro Characterisation of Probiotic Yeast Strains

In the present study, ten yeasts were isolated from fruit juices and subjected to in vitro tests for screening probiotic potentiality. Three isolates exhibited higher tolerance for pH and heat stress. Based on preliminary screening, isolates were subjected to molecular identification and identified as Wickerhamomyces anomalusVIT-ASN01, Saccharomyces cerevisiae VIT- ASN03 and Yarrowia lipolytica VIT- ASN04. The screened yeast isolates survived and grew well at human gastrointestinal conditions in pH 2.5 and 0.3% (w/v) oxgall at 37°C. The antagonistic activity of yeast isolates were tested against clinical pathogens, viz.S. typhii, B. subtilis and E. coli. W. anomalusVIT-ASN01 showed maximum tolerance to high bile salt concentration and acidity, could remove cholesterol 51.28% during 48 h and produced 586.55 mg/L of exopolysaccharide. It can be concluded that the screened novel yeast isolates can serve as promising probiotics in various fields of food industry.

Adsorption of Lactobacillus acidophilus on attapulgite: Kinetics and thermodynamics and survival in simulated gastrointestinal conditions

In the present study, we investigated the optimum adsorption conditions, adsorption characteristics and surviva of Lactobacillus acidophilus adsorbed on attapulgite (ATT). Results of single factor experiments showed that the optimum adsorption parameters were ATT concentration of 10%, initial pH of 6.5 and temperature of 35 °C. From the static experiments of adsorption characteristics, we found that the experimental data were fitted best to the pseudo-secondorder kinetics and Langmuir isotherm models, and the adsorption was a spontaneous and endothermic process. Bacteria survival test showed that the microencapsulated L. acidophilus stored at −18 °C for 30 days achieved the highest survival rate (83.2% ± 5.8) and obtained better protection at simulated conditions of gastric pH and at high bile salt concentrations when compared with free bacteria. The study demonstrated that microencapsulation of L. acidophilus in ATT was an effective technique of protection against low-temperature injury and under simulated gastrointestinal environment.

Proteomic Analysis of the Rat Canalicular Membrane Reveals Expression of a Complex System of P4-ATPases in Liver.

Transport processes in the canalicular membrane are key elements in bile formation and are the driving force of the enterohepatic circulation of bile salts. The canalicular membrane is constantly exposed to the detergent action of bile salts. One potential element protecting the canalicular membrane from the high canalicular bile salt concentrations may be bile salt resistant microdomains, however additional factors are likely to play a role. To obtain more insights into the molecular composition of the canalicular membrane, the proteome of highly purified rat canalicular membrane vesicles was determined. Isolated rat canalicular membrane vesicles were stripped from adhering proteins, deglycosylated and protease digested before subjecting the samples to shot gun proteomic analysis. The expression of individual candidates was studied by PCR, Western blotting and immunohistochemistry. A total of 2449 proteins were identified, of which 1282 were predicted to be membrane proteins. About 50% of the proteins identified here were absent from previously published liver proteomes. In addition to ATP8B1, four more P4-ATPases were identified. ATP8A1 and ATP9A showed expression specific to the canalicular membrane, ATP11C at the bLPM and ATP11A in an intracellular vesicular compartment partially colocalizing with RAB7A and EEA1 as markers of the endosomal compartment. This study helped to identify additional P4-ATPases from rat liver particularly in the canalicular membrane, previously not known to be expressed in liver. These P4-ATPases might be contributing for maintaining transmembrane lipid homeostasis in hepatocytes.

The Tolerance of &lt;em&gt;Lactobacillus paracasei&lt;/em&gt; and &lt;em&gt;Lactobacillus curvatus&lt;/em&gt; Originated from Bovine Colostrum towards Acidity and Bile Salts as a Probiotics Candidate

The studThe Tolerance of Lactobacillusy conducted to obtain Lactobacillus species from bovine colostrum as probiotic candidate that have resistant character towards acidity and bile salt condition. Research done experimentally with Factorial Completely Randomized Design Pattern. The results were analyzed using Analysis of Variance (ANOVA) followed by Duncan's Multiple Range Test (DMRT). Results showed that L. paracasei and L. curvatus have tolerance of pH 2 with colony population by 0.07102 CFU/mL. L. paracasei and L. curvatus also have tolerance as well towards 0.3% of bile salt concentration with colony population by 4.051010 CFU/mL and 0.5% of bile salt concentration with colony population by 4.021010 CFU/ml. L. paracasei and L. curvatus have character as probiotic because grew well at high acidity and bile salts condition.

The Prophylactic Effect of Probiotic Enterococcus lactis IW5 against Different Human Cancer Cells.

Enterococcus lactis IW5 was obtained from human gut and the potential probiotic characteristics of this organism were then evaluated. Results showed that this strain was highly resistant to low pH and high bile salt and adhered strongly to Caco-2 human epithelial colorectal cell lines. The supernatant of E. lactis IW5 strongly inhibited the growth of several pathogenic bacteria and decreased the viability of different cancer cells, such as HeLa, MCF-7, AGS, HT-29, and Caco-2. Conversely, E. lactis IW5 did not inhibit the viability of normal FHs-74 cells. This strain did not generate toxic enzymes, including β-glucosidase, β-glucuronidase, and N-acetyl-β-glucosaminidase and was highly susceptible to ampicillin, gentamycin, penicillin, vancomycin, clindamycin, sulfamethoxazol, and chloramphenicol but resistant to erythromycin and tetracyclin. This study provided evidence for the effect of E. lactis IW5 on cancer cells. Therefore, E. lactis IW5, as a bioactive therapeutics, should be subjected to other relevant tests to verify the therapeutic suitability of this strain for clinical applications.

Isolation, identification, and potential probiotic characterization of one Lactococcus from Kefir grain

“Probiotic” refers to viable microorganisms that promote or support a beneficial balance of the autochthonous microbial population of the gut. In the present study, we isolated and identified one potential probiotic of Lactococcus lactis WH-C1 from Tibetan Kefir grain. We assessed its probiotic and fermentation properties. WH-C1 showed good tolerance in the condition of high bile salt concentration and acidity. Moreover, WH-C1 could remove cholesterol from the culture medium at a percentage of 31.23% during 24 h and it had high capability of exopolysaccharide production. As part of starter culture it gave the better quality yogurt with good mouth feeling and a great viscosity. The solid-phase microextraction-gas chromatography-mass spectrometry analysis showed that fermented milk had 25 kinds of flavor compounds including acids, esters, alcohols, carbonyls, diacetyl, etc. In conclusion, our results showed that WH-C1 is a very promising strain which can be used in various fields.

Early to Late Endosome Trafficking Controls Secretion and Zymogen Activation in Rodent and Human Pancreatic Acinar Cells.

Background & AimsPancreatic acinar cells have an expanded apical endosomal system, the physiologic and pathophysiologic significance of which is still emerging. Phosphatidylinositol-3,5-bisphosphate [PI(3,5)P2] is an essential phospholipid generated by phosphatidylinositol 3-phosphate 5-kinase (PIKfyve), which phosphorylates phosphatidylinositol-3-phosphate (PI3P). PI(3,5)P2 is necessary for maturation of early endosomes (EE) to late endosomes (LE). Inhibition of EE to LE trafficking enhances anterograde endosomal trafficking and secretion at the plasma membrane by default through a recycling endosome (RE) intermediate. We assessed the effects of modulating PIKfyve activity on apical trafficking and pancreatitis responses in pancreatic acinar cells.MethodsInhibition of EE to LE trafficking was achieved using pharmacologic inhibitors of PIKfyve, expression of dominant negative PIKfyve K1877E, or constitutively active Rab5-GTP Q79L. Anterograde endosomal trafficking was manipulated by expression of constitutively active and dominant negative Rab11a mutants. The effects of these agents on secretion, endolysosomal exocytosis of lysosome associated membrane protein (LAMP1), and trypsinogen activation in response to supramaximal cholecystokinin (CCK-8), bile acids, and cigarette toxin was determined.ResultsPIKfyve inhibition increased basal and stimulated secretion. Adenoviral overexpression of PIKfyve decreased secretion leading to cellular death. Expression of Rab5-GTP Q79L or Rab11a-GTP Q70L enhanced secretion. Conversely, dominant-negative Rab11a-GDP S25N reduced secretion. High-dose CCK inhibited endolysosomal exocytosis that was reversed by PIKfyve inhibition. PIKfyve inhibition blocked intracellular trypsin accumulation and cellular damage responses to supramaximal CCK-8, tobacco toxin, and bile salts in both rodent and human acini.ConclusionsThese data demonstrate that EE-LE trafficking acutely controls acinar secretion and the intracellular activation of zymogens, leading to the pathogenicity of acute pancreatitis.