Polysaccharide BAP1 of Bifidobacterium adolescentis CCDM 368 is a biologically active molecule with immunomodulatory properties.

Bifidobacteria are among the most common bacteria used for their probiotic properties and their impact on the maturation and function of the immune system has been well-described. Recently, scientific interest is shifting from live bacteria to defined bacteria-derived biologically active molecules. Their greatest advantage over probiotics is the defined structure and the effect independent of the viability status of the bacteria. Here, we aim to characterize Bifidobacterium adolescentis CCDM 368 surface antigens that include polysaccharides (PSs), lipoteichoic acids (LTAs), and peptidoglycan (PG). Among them, Bad368.1 PS was observed to modulate OVA-induced cytokine production in cells isolated from OVA-sensitized mice by increasing the production of Th1-related IFN-γ and inhibition of Th2-related IL-5 and IL-13 cytokines (in vitro). Moreover, Bad368.1 PS (BAP1) is efficiently engulfed and transferred between epithelial and dendritic cells. Therefore, we propose that the Bad368.1 PS (BAP1) can be used for the modulation of allergic diseases in humans. Structural studies revealed that Bad368.1 PS has an average molecular mass of approximately 9,99 × 106 Da and it consists of glucose, galactose, and rhamnose residues that are creating the following repeating unit: →2)-ß-D-Glcp-1→3-ß-L-Rhap-1→4-ß-D-Glcp-1→3-α-L-Rhap-1→4-ß-D-Glcp-1→3-α-D-Galp-(1→n.

Bifidobacterium infantis strain YLGB-1496 possesses excellent antioxidant and skin barrier-enhancing efficacy in vitro.

Atopic dermatitis (AD) is a recurring allergic skin disease that has a high incidence. Orally applied Bifidobacteria ameliorate signs of irritated skin and enhance the skin barrier. The present study investigated the safety and efficacy of a topically used cell-free culture supernatant (CFS) from a Bifidobacterium infantis strain using in vitro evaluation methods. The results showed that CFS had strong free radical scavenging activity on DPPH, ABTS, ·OH and O2 -radicals. CFS treatment fundamentally reduced the intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) contents and improved the activities of antioxidant enzymes (CAT, SOD and GSH-Px) in H2 O2 -treated HaCaT cells. Notably, the upregulation of skin physical barrier gene (FLG, LOR, IVL, AQP3 and TGM1) expression and skin antimicrobial peptide gene (CAMP, hBD-2 and hBD-3) expression by CFS might contribute to skin barrier resistance. CFS was non-irritating to the skin and eyes. CFS from the Bifidobacterium infantis strain had strong antioxidant properties on the skin and strengthened skin barrier function, and it was safe for topical use.

Efficient isolation of membrane-associated exopolysaccharides of four commercial bifidobacterial strains.

Bifidobacteria confer many health effects, such as fiber digestion, pathogen inhibition and immune system maturation, especially in the newborn infant. The bifidobacterial exopolysaccharides (EPS) are often associated with important health effects, but their thorough investigation is hampered by lack of knowledge of the EPS localization, which is important for efficient EPS isolation. Here we present a straightforward isolation procedure to obtain EPS of four commercial bifidobacterial strains (B. adolescentis, B. bifidum, B. breve, and B. infantis), that are localized at the cell membrane (evidenced using cryo-EM). This procedure can be applied to other bifidobacterial strains, to facilitate the easy isolation and purification for biological experiments and future application in nutraceuticals. In addition, we demonstrate structural differences in the EPS of the four bifidobacterial strains, in terms of monosaccharide composition and size, highlighting the potential of the isolated EPS for determining specific structure-activity effects of bifidobacteria.

Bifidobacterium species associated with breastfeeding produce aromatic lactic acids in the infant gut.

Breastfeeding profoundly shapes the infant gut microbiota, which is critical for early life immune development, and the gut microbiota can impact host physiology in various ways, such as through the production of metabolites. However, few breastmilk-dependent microbial metabolites mediating host-microbiota interactions are currently known. Here, we demonstrate that breastmilk-promoted Bifidobacterium species convert aromatic amino acids (tryptophan, phenylalanine and tyrosine) into their respective aromatic lactic acids (indolelactic acid, phenyllactic acid and 4-hydroxyphenyllactic acid) via a previously unrecognized aromatic lactate dehydrogenase (ALDH). The ability of Bifidobacterium species to convert aromatic amino acids to their lactic acid derivatives was confirmed using monocolonized mice. Longitudinal profiling of the faecal microbiota composition and metabolome of Danish infants (n = 25), from birth until 6 months of age, showed that faecal concentrations of aromatic lactic acids are correlated positively with the abundance of human milk oligosaccharide-degrading Bifidobacterium species containing the ALDH, including Bifidobacterium longum, B. breve and B. bifidum. We further demonstrate that faecal concentrations of Bifidobacterium-derived indolelactic acid are associated with the capacity of these samples to activate in vitro the aryl hydrocarbon receptor (AhR), a receptor important for controlling intestinal homoeostasis and immune responses. Finally, we show that indolelactic acid modulates ex vivo immune responses of human CD4+ T cells and monocytes in a dose-dependent manner by acting as an agonist of both the AhR and hydroxycarboxylic acid receptor 3 (HCA3). Our findings reveal that breastmilk-promoted Bifidobacterium species produce aromatic lactic acids in the gut of infants and suggest that these microbial metabolites may impact immune function in early life.

Architecture Insight of Bifidobacterial α-L-Fucosidases.

Fucosylated carbohydrates and glycoproteins from human breast milk are essential for the development of the gut microbiota in early life because they are selectively metabolized by bifidobacteria. In this regard, α-L-fucosidases play a key role in this successful bifidobacterial colonization allowing the utilization of these substrates. Although a considerable number of α-L-fucosidases from bifidobacteria have been identified by computational analysis, only a few of them have been characterized. Hitherto, α-L-fucosidases are classified into three families: GH29, GH95, and GH151, based on their catalytic structure. However, bifidobacterial α-L-fucosidases belonging to a particular family show significant differences in their sequence. Because this fact could underlie distinct phylogenetic evolution, here extensive similarity searches and comparative analyses of the bifidobacterial α-L-fucosidases identified were carried out with the assistance of previous physicochemical studies available. This work reveals four and two paralogue bifidobacterial fucosidase groups within GH29 and GH95 families, respectively. Moreover, Bifidobacterium longum subsp. infantis species exhibited the greatest number of phylogenetic lineages in their fucosidases clustered in every family: GH29, GH95, and GH151. Since α-L-fucosidases phylogenetically descended from other glycosyl hydrolase families, we hypothesized that they could exhibit additional glycosidase activities other than fucosidase, raising the possibility of their application to transfucosylate substrates other than lactose in order to synthesis novel prebiotics.

Measuring Conjugated Linoleic Acid (CLA) Production by Bifidobacteria.

The biological significance of conjugated fatty acids (CFAs) has been linked to positive health effects based on biomedical, in vitro, and clinical studies. Of note, conjugated linoleic acids (CLAs) are the most widely characterized fatty acids as geometric isomers cis-9,trans-11 and trans-10,cis-12 CLA occur naturally in ruminant fats, dairy products, and hydrogenated oils. Concerning CLAs, it is known that bacterial biohydrogenation, a process whereby ruminal bacteria or starter cultures of lactic acid bacteria have the ability to synthesize CLA by altering the chemical structure of essential fatty acids via enzymatic mechanisms, produces a multitude of isomers with desirable properties. Bifidobacterium species are classed as food grade microorganisms and some of these strains harness molecular determinants that are responsible for the bioconversion of free fatty acids to CLAs. However, molecular mechanisms have yet to be fully elucidated. Reports pertaining to CLAs have been attributed to suppressing tumor growth, delaying the onset of diabetes mellitus and reducing body fat in obese individuals. Given the increased attention for their bioactive properties, we describe in this chapter the qualitative and quantitative methods used to identify and quantify CLA isomers produced by bifidobacterial strains in supplemented broth media. These approaches enable rapid detection of potential CLA producing strains and accurate measurement of fatty acids in biological matrices.

Detection, Isolation, and Purification of Bifidobacterial Exopolysaccharides.

This chapter describes some of the available methods to assess EPS production in bifidobacteria, being largely based on those developed for the same purpose for members of the lactic acid bacteria group. The first step is detection of putative EPS-producing bifidobacteria based on a mucoid and/or ropy phenotype. Next, a basic procedure is described for the isolation of the glycan polymer based on the release from bifidobacterial cells grown and collected from the surface of agar-MRSc ("crude EPS"), followed by a purification procedure intended to remove other bacterial macromolecules (DNA and proteinaceous material) to generate "purified EPS." Finally, several methods used for quantification and physical-chemical characterization of isolated/purified polysaccharide are outlined.

In Vitro Assessment of Prebiotic Activity.

Bifidogenic effect is a main target for the assessment of prebiotic activity. pH-controlled batch processes of bifidobacteria and fecal microbiota are herein presented. Growth of bifidobacteria, carbohydrate breakdown and consumption, organic acid production, and activity of specific glycosyl hydrolases involved in the hydrolysis of di-, oligo-, or polysaccharides are exploited to study and compare substrate preference of bifidobacteria for candidate prebiotics.

Analytic and chemometric assessments of the native probiotic bacteria and inulin effects on bioremediation of lead salts.

BACKGROUND: Lead (Pb2+ ) is one of the most toxic heavy metals and can be found in various quantities in the environment. The five native probiotic bacteria and inulin were used to assess in vitro lead nitrate and lead acetate binding capacities, as well as removal potentials. RESULTS: The highest decrease in media pH was seen for samples containing a combination of Lactobacillus paracasei IRBC-M 10784, lead nitrate and inulin (5.30 ± 0.012). The presence of inulin in the environment accelerated decreases in the pH of all samples with no significance. In all groups, lead nitrate-containing samples included maximum pH decreases. From the highest to the lowest, the ability of lead removal was linked to Lactobacillus acidophilus PTCC-1932 (88.48%), Bifidobacterium bifidum BIA-7 (85.32%), Bifidobacterium lactis BIA-6 (85.24%), Lactobacillus rhamnosus IBRC-M 10782 (83.18%) and L. paracasei IRBC-M 10784 (80.66%). Most species included the highest decrease in lead nitrate. Fourier-transform infrared spectroscopy (FTIR) analysis demonstrated that various functional groups (hydroxyl, carboxylic, carbonyl, amino and amide binds) on the bacterial cell wall were involved in lead ion binding during incubation. Principal component analysis of the FTIR results showed differences with respect to treated groups and control groups. CONCLUSION: The results obtained in the present study reveal that the simultaneous use of native probiotics and inulin can be an effective and safe approach for removing various toxic substances, especially Pb. © 2021 Society of Chemical Industry.

Fabrication of fish gelatin / sodium alginate double network gels for encapsulation of probiotics.

BACKGROUND: To improve the environmental resistance of probiotics, and particularly their survival in the gastrointestinal environment, a fish gelatin (FG) / sodium alginate (SA) double network gelation (FSDN) was developed to encapsulate them. Thermal treatment and calcium ion inducement were adopted to fabricate fish gelatin and sodium alginate gels. It was feasible to scale up this process. The effects of FG concentration (0-60 g/L) on FSDN properties, including morphology, water-holding capacity, and encapsulation efficiency were evaluated. RESULTS: The results indicated that the addition of FG could improve the transparency, rehydration, and water-holding capacity of FSDN. Scanning electronic microscope (SEM) images revealed that FSDN had a denser and more complete structure than SA. Encapsulation efficiency improved from 15.85% to 91.91% as the FG concentration ranged from 0 to 50 g/L. Bifidobacterium longum embedded by FSDN showed better thermal stability than when it was free. Compared with bare probiotics (1.7%), the encapsulated ones exhibited higher viability (above 15%) in simulated gastric fluid. CONCLUSION: In conclusion, interpenetrating FSDN is an effective barrier constituent and could achieve the targeted delivery of probiotics. It is a potential new delivery carrier for the oral administration of probiotics. © 2021 Society of Chemical Industry.

Structural Comparison of Different Galacto-oligosaccharide Mixtures Formed by ß-Galactosidases from Lactic Acid Bacteria and Bifidobacteria.

The LacLM-type ß-galactosidase from Lactobacillus helveticus DSM 20075 expressed in both Escherichia coli (EcoliBL21Lhß-gal) and Lactobacillus plantarum (Lp609Lhß-gal) was tested for their potential to form galacto-oligosaccharides (GOS) from lactose. The Lh-GOS mixture formed by ß-galactosidase from L. helveticus, together with three GOS mixtures produced using ß-galactosidases of both the LacLM and the LacZ type from other lactic acid bacteria, namely, L. reuteri (Lr-GOS), L. bulgaricus (Lb-GOS), and Streptococcus thermophilus (St-GOS), as well as two GOS mixtures (Br-GOS1 and Br-GOS2) produced using ß-galactosidases (ß-gal I and ß-gal II) from Bifidobacterium breve, was analyzed and structurally compared with commercial GOS mixtures analyzed in previous work (Vivinal GOS, GOS I, GOS III, and GOS V) using high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD), high-performance size-exclusion chromatography with a refractive index (RI) detector (HPSEC-RI), and one-dimensional 1H NMR spectroscopy. ß-Galactosidases from lactic acid bacteria and B. breve displayed a preference to form ß-(1→6)- and ß-(1→3)-linked GOS. The GOS mixtures produced by these enzymes consisted of mainly DP2 and DP3 oligosaccharides, accounting for ∼90% of all GOS components. GOS mixtures obtained with ß-galactosidases from lactic acid bacteria and B. breve were quite similar to the commercial GOS III mixture in terms of product spectrum and showed a broader product spectrum than the commercial GOS V mixture. These GOS mixtures also contained a number of GOS components that were absent in the commercial Vivinal GOS (V-GOS).

A Combined Proteomics, Metabolomics and In Vivo Analysis Approach for the Characterization of Probiotics in Large-Scale Production.

The manufacturing processes of commercial probiotic strains may be affected in different ways in the attempt to optimize yield, costs, functionality, or stability, influencing gene expression, protein patterns, or metabolic output. Aim of this work is to compare different samples of a high concentration (450 billion bacteria) multispecies (8 strains) formulation produced at two different manufacturing sites, United States of America (US) and Italy (IT), by applying a combination of functional proteomics, metabolomics, and in vivo analyses. Several protein-profile differences were detected between IT- and US-made products, with Lactobacillus paracasei, Streptococcus thermophilus, and Bifidobacteria being the main affected probiotics/microorganisms. Performing proton nuclear magnetic spectroscopy (1H-NMR), some discrepancies in amino acid, lactate, betaine and sucrose concentrations were also reported between the two products. Finally, we investigated the health-promoting and antiaging effects of both products in the model organism Caenorhabditis elegans. The integration of omics platforms with in vivo analysis has emerged as a powerful tool to assess manufacturing procedures.

Bifidobacteria cell wall-derived exo-polysaccharides, lipoteichoic acids, peptidoglycans, polar lipids and proteins - their chemical structure and biological attributes.

A variety of health benefits has been documented to be associated with the consumption of probiotic bacteria, namely bifidobacteria and lactobacilli. Thanks to the scientific advances in recent years we are beginning to understand the molecular mechanisms by which bacteria in general and probiotic bacteria in particular act as host physiology and immune system modulators. More recently, the focus has shifted from live bacteria towards bacteria-derived defined molecules, so called postbiotics. These molecules may represent safer alternative compared to the live bacteria while retaining the desired effects on the host. The excellent source of effector macromolecules is the bacterial envelope. It contains compounds that are pivotal in the adhesion phenomenon, provide direct bacteria-to-host signaling capacity and the associated physiological impact and immunomodulatory properties of bacteria. Here we comprehensively review the structure and biological role of Bifidobacterium surface and cell wall molecules: exopolysaccharides, cell wall polysaccharides, lipoteichoic acids, polar lipids, peptidoglycans and proteins. We discuss their involvement in direct signaling to the host cells and their described immunomodulatory effects.

Characterization of Bifidobacterium species in feaces of the Egyptian fruit bat: Description of B. vespertilionis sp. nov. and B. rousetti sp. nov.

Fifteen bifidobacterial strains were obtained from faeces of Rousettus aegyptiacus; after grouping them by RAPD PCR only eight were selected and characterized. Analysis of 16S rRNA and of five housekeeping (hsp60, rpoB, clpC, dnaJ, dna G) genes revealed that these eight strains were classified into five clusters: Cluster I (RST 8 and RST 16T), Cluster II (RST 9T and RST 27), Cluster III (RST 7 and RST 11), Cluster IV (RST 19), Cluster V (RST 17) were closest to Bifidobacterium avesanii DSM 100685T (96.3%), Bifidobacterium callitrichos DSM 23973T (99.2% and 99.7%), Bifidobacterium tissieri DSM 100201T (99.7 and 99.2%), Bifidobacterium reuteri DSM 23975 T (98.9%) and Bifidobacterium myosotis DSM 100196T (99.3%), respectively. Strains in Cluster I and strain RST 9 in Cluster II could not be placed within any recognized species while the other ones were identified as known species. The average nucleotide identity values between two novel strains, RST 16T and RST 9T and their closest relatives were lower than 79% and 89%, respectively. In silico DNA-DNA hybridization values for those closest relatives were 32.5 and 42.1%, respectively. Phenotypic and genotypic tests demonstrated that strains in Cluster I and RST 9T in Cluster II represent two novel species for which the names Bifidobacterium vespertilionis sp. nov. (RST 16T=BCRC 81138T=NBRC 113380T=DSM 106025T ; RST 8=BCRC 81135=NBRC 113377) and Bifidobacterium rousetti sp. nov. (RST 9T=BCRC 81136T=NBRC 113378T=DSM 106027T) are proposed.

Screening of Bifidobacterium strains with assignment of functional groups to bind with benzo[a]pyrene under food stress factors.

The purpose of this study was to find the component of the Bifidobacterium cell wall more particularly the functional groups from peptidoglycan involved in the mechanism of binding with Benzo[a]pyrene. Additionally, the effect of different stress factors (acid, heat, alkaline, oxidative, osmotic, enzymatic, and detergent factors) on the functional group and the overall binding mechanism of Bifidobacterium with B[a]p were also evaluated. Scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) were used to explain the binding mechanism of Bifidobacterium with B[a]p along with HPLC (high-performance liquid chromatography). The peptidoglycan-B[a]p complexes were highly stable after benzene washing. Peptidoglycan from Bifidobacterium infantis BY12 showed highest binding rate with B[a]p out of nine selected strains. FTIR spectra showed that the main functional groups involved in B[a]p binding were CO, OH and/or NH. FTIR spectrums along with SEM electrographs as a function of stress factors reveal that peptidoglycan structural integrity is important in B[a]p binding. Bifidobacterium longum subsp. infantis BY12 may be employed as a biological detoxification agent for the elimination of B[a]p from human diet and animal feed in the future.

Experimental Study of Retention on the Combination of Bifidobacterium with High-Intensity Focused Ultrasound (HIFU) Synergistic Substance in Tumor Tissues.

High intensity focused ultrasound (HIFU) has been recently regarded to be a new type of technique for non-invasive ablation of local tumors and HIFU synergists could significantly improve its therapeutic efficiency. The therapeutic efficiency of HIFU is greatly limited by the low retention of HIFU synergists in the target area and short residence time. This study aimed to explore a method to increase the deposition of HIFU synergists in tumors. Cationic lipid nanoparticle can be used to enhance the HIFU ablation effect, but there is still a problem for it that the deposition amount in the tumor tissue is small and the residence time is short. Bifidobacterium is highly biosafe and can be selectively colonized in the hypoxic zone of tumor tissue. Cationic lipid nanoparticles can be observed in vitro by attachment to bifidobacterium by electrostatic adsorption. And the effect of the proliferation of bifidobacterium in tumor tissues on the retention amount and retention time of cationic lipid nanoparticles in vivo was evaluated. Results showed that the cationic lipid nanoparticles were linked to the surface of Bifidobacterium effectively in vitro, while in vivo, the retention amount and retention time of cationic lipid nanoparticles could be increased by Bifidobacterium in tumor tissues, which provided a new method for improving the therapeutic efficiency of HIFU.

Dietary effects of commercial probiotics on growth performance, digestibility, and intestinal morphometry of broiler chickens.

This study compared five commercially available probiotics vis-à-vis antibiotic growth promotant (AGP) supplementation and absence of feed additive based on efficiency, intestinal morphometry, and energy digestibility in improving broiler chicken production. A total of 630 straight run (Cobb) day-old broiler chicks were distributed to seven treatments following a completely randomized design, with ten replicates per treatment and nine birds per replicate per cage. Dietary treatments consisted of basal diet in combination with the following: without probiotics and AGP supplementation (treatment 1); 75 ppm each of chlorotetracycline (CTC) and Zn bacitracin (treatment 2); probiotic A, Bacillus subtilis (treatment 3); probiotic B, Bacillus subtilis (treatment 4); probiotic C, Enterococcus faecium (treatment 5); and probiotic D, Bacillus subtilis (treatment 6); probiotic E, Enterococcus faecium, Bifidobacterium spp., Pediococcus spp., and Lactobacillus spp. (treatment 7). At day 42, energy digestibility was determined by fasting three randomly selected birds from each treatment for 12 h and then subjecting them to their corresponding dietary treatments. Excreta were collected and pooled after 24 h of feeding. Pooled excreta were weighed, oven-dried, and subjected to energy analyses after 3-day collection. Apparent total tract metabolizable energy was then computed. At day 47, three birds were randomly selected per treatment for intestinal morphometry (villi height and crypt depth) of the duodenum, jejunum, and ileum. Dietary supplementation using probiotics showed no significant effect on overall body weight, weight gain, feed consumption, feed efficiency, dressing percentage, mortality, harvest recovery, carcass quality parameters (e.g., meat to bone ratio and abdominal fat content), intestinal morphometry, and energy digestibility. Birds under treatment 7 (basal feed + probiotic E) generated the highest income over feed and chick cost.

Identification of an anti-lipopolysaccharide factor AV-R isoform (LvALF AV-R) related to Vp_PirAB-like toxin resistance in Litopenaeus vannamei.

Acute hepatopancreatic necrosis disease (AHPND) is a shrimp farming disease, caused by the pathogenic Vibrio parahaemolyticus carrying a plasmid encoding Vp_PirAB-like toxins. Formalin-killed cells of V. parahaemolyticus AHPND-causing strain D6 (FKC-VpD6) were used to select Vp_PirAB-like toxin-resistant Litopenaeus vannamei by oral administration. Stomach and hepatopancreas tissues of shrimps that survived for one week were subjected to RNA sequencing. Differentially expressed genes (DEGs) between surviving shrimp, AHPND-infected shrimp, and normal shrimp were identified. The expressions of 10 DEGs were validated by qPCR. Only one gene (a gene homologous to L. vannamei anti-lipopolysaccharide factor AV-R isoform (LvALF AV-R)) was expressed significantly more strongly in the hepatopancreas of surviving shrimp than in the other groups. Significantly higher expression of LvALF AV-R was also observed in shrimp that survived two other trials of FKC-VpD6 selection. Recombinant ALF AV-R bound to LPS, PGN, Gram-negative bacteria, and some Gram-positive bacteria in ELISAs. ALF AV-R recombinant protein did not interact with native Vp_PirAB-like toxin in an ELISA or a Far-Western blot. For L. vannamei orally fed ALF AV-R protein for 3 days, the survival rate following challenge with VpD6-immersion was not significantly different from that of shrimp fed two control diets. These results suggest that LvALF AV-R expression was induced in the hepatopancreas of shrimp in response to the presence of Vp_PirAB-like toxin, although other factors might also be involved in the resistance mechanism.

The Effect of Encapsulation on The Stability of Probiotic Bacteria in Ice Cream and Simulated Gastrointestinal Conditions.

The objective of this work was to explore the effect of two encapsulating polysaccharides (sodium alginate and carrageenan) on the viability of probiotic bacteria (L. acidophilus) in ice cream and under simulated gastrointestinal (GIT) conditions. For the purpose, probiotic cells were encapsulated in sodium alginate and carrageenan by an encapsulator using standard operating conditions. Ice cream was manufactured by adding free and microencapsulated probiotics. The survival of free and encapsulated probiotics was monitored over a period of 120 days at - 20 °C. Furthermore, the survival of free and encapsulated probiotic bacteria under the simulated GIT conditions was investigated. The results of the study showed that encapsulation significantly (p < 0.05) improved the cell survival of probiotics in ice cream compared to free cells (non-encapsulated). The viable cell count of probiotic bacteria in the free-state in ice cream was 9.97 log cfu/ml at 0 day that decreased to 6.12 log cfu/ml after 120 days. However, encapsulation improved the viability of the probiotics in the prepared ice cream and GIT. The cell count of probiotics encapsulated with sodium alginate and carrageenan was 9.91 log cfu/ml and 9.89 log cfu/ml respectively at 0 day that decreased to 8.74 log cfu/ml and 8.39 log cfu/ml respectively after 120 days. Similarly, during simulated gastrointestinal assay, the survival rate of encapsulated probiotic bacteria in simulated gastric solution and intestinal solutions was higher than that of free cells. In the case of encapsulated bacteria, only three log while for free cells seven log reduction was recorded. Sodium alginate microcapsules exhibited better release profile than carrageenan. Conclusively, the incorporation of encapsulated probiotics had a significant effect on quality parameters and sensorial characteristics of ice cream.

Increasing Antiradical Activity of Polyphenols from Lotus Seed Epicarp by Probiotic Bacteria Bioconversion.

Probiotic bacteria is able to metabolize polyphenols and produce functional compounds. In this study, we investigated the ability of probiotic bacteria including Lactobacillus, bifidobacteria and Enterococcus strains to increase the antioxidant capacity of polyphenols from lotus seed epicarp (PLSE) at full ripening stage. The results showed that the six selected strains of probiotic bacteria grew well in De Man, Rogosa and Sharpe (MRS) broth with PLSE, and their resistant extent to PLSE varied from strain to strain. The metabolized PLSE was found to have good antioxidant properties on 3-ethylbenzothiazoline-6-sulfonic acid (ABTS⁺) and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radicals in vitro. Five polyphenol compounds-chlorogenic acid, caffeic acid, catechin, epicatechin and hyperoside-were suggested as the major bioactive metabolism for the antiradical activity of PLSE metabolized by Lactobacillus reuteri DSM20016, Enterococcus faecalis M74 and Bifidobacterium breve ATCC 15701. Moreover, L. reuteri DSM20016 and E. faecalis M74 were found to have a high PLSE bioconversion rate. Our results suggested that both L. reuteri DSM20016 and E. faecalis M74 might have excellent potential for the bioconversion of PLSE to increase its antiradical activity.