Structural and biosynthetic diversity of plantaricins from Lactiplantibacillus

Lactiplantibacillus plantarum (L. plantarum) produces an antimicrobial peptide known as plantaricin. Plantaricin-producing L. plantarum is of interest for its gut-friendly nature, wide range of sugar utilization, palatability, and probiotic attributes, making it a better candidate for the food industry. Numerous strains of plantaricin-producing L. plantarum have been isolated from different ecological niches and found to follow different mechanisms for plantaricin production. The mechanism of plantaricin production is sensitive to environmental factors; therefore, any alteration in the optimum conditions can inhibit/halt bacteriocin production. To regain the lost or hidden plantaricin-producing character of the L. plantarum strains under ideal laboratory conditions, it is essential to understand the mechanism of plantaricin production. Previously, discrete information on various mechanisms of plantaricin production has been elaborated. However, based on the literature analysis, we observed that a systematic classification of plantaricins produced by L. plantarum is not explored. Hence, we aim to collect information about rapidly emerging plantaricins and distribute them among the different classes of bacteriocin, followed by classifying them based on different mechanisms of plantaricin production. This may help scaleup the bacteriocin production at industrial levels, which is otherwise challenging to achieve. This will also help the reader understand plantaricins and their mechanism of plantaricin production to a deeper extent and to characterize/reproduce the peptide where plantaricin production is a hidden character. KEY POINTS: • L. plantarum produces the antimicrobial compound plantaricin. • L. plantarum has different regulatory operons which control plantaricin production. • Based on the regulatory operon, the mechanism of plantaricin production is different.

Probiotic Bacillus licheniformis MCC2514 and Bifidobacterium breve NCIM 5671 Regulates GATA3 and Foxp3 Expression in the Elevated Disease Condition

TNBS-induced ulcerative colitis was evaluated using Bacillus licheniformis MCC 2514 (B. licheniformis) and Bifidobacterium breve NCIM 5671 (Bf. breve) as immune modulators. The study aims to analyze probiotic efficiency of ulcerative colitis induced by TNBS in Wistar rats. The tumor-like structure was found in the colon of TNBS inflammation-induced rats. Nitric oxide production was inhibited by about 65.2% fed with combination of bacteria and C-reactive protein, and decreased by 12% and 10.8% upon supplementing B. licheniformis and Bf. breve against the TNBS-treated rats, respectively. Liver damage was observed in the TNBS-treated rats; addition of probiotic bacteria reduced SGPT (75.4%) and SGOT (42.5%). On TNBS treatment, the transcriptional factor responsible for Th2 cell immune response (GATA3) was analyzed, and the elevation in gene expression (5.31-fold) was found. The FOXP-3 responsible for T-regulatory cells was expressed about 0.91-fold upon the treatment with a combination of bacteria. The expression of antioxidant genes such as iNOS (1.11-fold), GPx (1.29-fold), and PON1 (1.48-fold) has been increased when compared with that of the TNBS-treated group. The cytokines specific to Th2-driven immune response, such as IL-4, IL-5, and TNF-α, were reduced upon feeding the bacteria. It is observed that the B. licheniformis and Bf. breve used in the study have reduced Th2-driven immune response.

The Combined Effect of Potential Probiotic Bacillus licheniformis MCC 2514 and Bifidobacterium breve NCIM 5671 Towards Anti-inflammatory Activity on HT-29 Cell Lines

Probiotics are considered a natural source for treating many intestinal disorders, which deliver health benefits in different ways. The study aims to evaluate the immunomodulatory gene expression on HT-29 cell line using Bacillus licheniformis MCC 2514 and Bifidobacterium breve NCIM 5671 as a single culture and in combination. Upon inflammation induced by LPS, the combination of bacteria downregulated the pro-inflammatory cytokines IL-1α (13.4), IL-12 (14.6), IL-8 (2.6), and IL-6 (1.9), and in contrast, TNF-α (21.2) folds has upregulated. However, anti-inflammatory genes such as IL-4 (0.6), IL-10 (2.9), TGF-2 (92.2), and TGF-3 (85.8) folds were upregulated. The combination of bacteria against oxidative stress downregulated the pro-inflammatory cytokines such as IL-1α & β, IL-6, IL-8, IL-12, and IL-18, and upregulated the anti-inflammatory cytokines IL-10, IL-4, TGF-2, and TGF-3. On the introduction of Kocuria rhizophila, the pro-inflammatory cytokines were upregulated. On supplementation of B. licheniformis and B. breve, the upregulated pro-inflammatory cytokines were decreased, and anti-inflammatory cytokines such as IL-4 (6.2), IL-10 (23.5), TGF-2 (166), and TGF-3(28.4) folds were increased. However, gene expression of toll-like receptor-2 was found high (26 folds) upon introducing probiotic bacteria. ELISA results of Interferon-γ found that the expression was higher (7.19 ng/mL) on the introduction of both the bacteria in combination. The higher anti-inflammatory activity was observed when potential probiotic bacteria were used in combination compared to a single culture. Overall study indicates that the combination of aerobic B. licheniformis and anaerobic B. breve has an anti-inflammatory activity that can sustain an excellent gastrointestinal environment during pathogen invasion and inflammation.

In vitro validation studies for adhesion factor and adhesion efficiency of probiotic Bacillus licheniformis MCC 2514 and Bifidobacterium breve NCIM 5671 on HT-29 cell lines

Probiotic bacterial adhesion to the epithelial cell is a composite process and in vivo adhesion studies can be strengthened with the improved in vitro models for preliminary screening of potentially adherent strains. With this rationale, the study aimed is the first report to demonstrate the colonizing efficiency of probiotic Bacillus licheniformis MCC 2514 in comparison to Bifidobacterium breve NCIM 5671on HT-29 cell line. B. licheniformis (54.28 ± 0.99%) and Bif. breve (70.23 ± 0.85%) adhered in a higher percentage on fibronectin and mucin, respectively. However, the adhesion was higher for B. licheniformis when compared to Bif. breve. In adhesion score, B. licheniformis obtained about 138.85 ± 12.32, whereas Bif. breve got the score of 43.05 ± 9.12. The same trend continued in the adhesion percentage study, where B. licheniformis adhered 75.5 ± 5.2%, higher than Bif. breve which adhered 32.66 ± 3.2%. In invasion assay, both the bacteria significantly decreased the colonization of the pathogen Kocuria rhizophila ATCC 9341 about 97.32 ± 0.81% in the competitive assay, 97.87 ± 0.73% in exclusion assay and 82.19 ± 2.51% in displacement assay. The cytotoxicity effects of the test bacterial strains against HT-29 cell line through MTT assay determined no viability loss in the treated cells. Therefore, the data obtained from the in vitro studies showed that both B. licheniformis and Bif. breve had shown significantly good invasion on pathogen and adhesion capacity on HT-29 cell line.

Effect of Lactobacillus fermentum MCC2760-Based Probiotic Curd on Hypercholesterolemic C57BL6 Mice

Lactobacillus fermentum MCC2760 is a probiotic strain proven earlier for cholesterol-reducing and anti-inflammatory properties in vitro and in vivo. This study investigates L. fermentum MCC2760-based probiotic curd in high-cholesterol diet (HCD)-fed C57BL6 mice. The mice were grouped into normal diet control, high-cholesterol diet control, normal diet with probiotic supplementation, and high-cholesterol diet with probiotic supplementation. Control groups and treatment groups were supplemented with market curd and probiotic curd, respectively, via oral gavage for eight weeks. The probiotic count was maintained at 10.95 log CFU/mL in the developed probiotic curd. The HCD group showed an increase in feed intake and body weight. Reduction in the levels of serum cholesterol, triglycerides, low-density lipoprotein cholesterol, glucose, aspartate aminotransferase, and alanine transaminase was observed in probiotic-supplemented groups. The probiotic-supplemented group resulted in an increase in Lactobacillus spp. count along with reduced pathogen count in the feces. Probiotic supplementation also showed a reduction in the bacterial translocation count in mesenteric adipose tissue. Expression of inflammatory markers by qPCR showed the decline in the fold change of TNF-α, IL-6, and IL-12 and elevation in the fold change of IL-10 in the adipose tissue of the probiotic-treated group. Probiotic supplementation also improved the expression of GLP-1, ZO-1, and CB2 in the intestine. They were thus possibly playing a role in the enhancement of barrier function. Histopathological sections showed improvement in the cellular infiltration and pathological indications due to the high-cholesterol diet intake. Our study also confirmed that probiotics could increase serum antioxidant enzymes in treated groups, showing their beneficial antioxidant activity. It suggests the anti-inflammatory, antioxidant effect, and gut barrier function of the given probiotic formulation, which ameliorate hypercholesterolemia.

Lactobacillus fermentum MCC2759 and MCC2760 Alleviate Inflammation and Intestinal Function in High-Fat Diet-Fed and Streptozotocin-Induced Diabetic Rats

The growing incidence of type 2 diabetes and obesity has become a worldwide crisis with increased socio-economic burden. Changes in lifestyle and food habits resulting in dysbiosis of the gut microbiota and low-grade inflammation are linked to the rising incidence. The aim of this study was to investigate the effects of potential probiotic Lactobacillus fermentum MCC2759 and MCC2760 on intestinal markers of inflammation using a high-fat diet (HFD)-fed model and a streptozotocin (STZ)-induced diabetic model. Lact. fermentum administration showed improved oral glucose tolerance compared with the model controls of HFD (AUC 1518) and STZ (628.8). Plasma insulin levels improved in the Lact. fermentum treated groups of HFD + MCC2759 (129 ± 4.24 pmol/L) and HFD + MCC2760 (151.5 ± 9.19 pmol/L) in HFD study, while in STZ diabetic study, the insulin levels were normalized with Lact. fermentum administration, for D + MCC2759 (120.5 ± 7.77) and D + MCC2760 (138 ± 5.65 pmol/L) groups. The results showed reduction in inflammatory tone in liver, muscle, and adipose tissues of rats in both models with stimulation of anti-inflammatory IL-10 by real-time quantitative polymerase chain reaction. Additionally, the potential probiotic cultures also displayed normalization of markers related to intestinal barrier integrity (ZO-1), TLR-4 receptor, and insulin sensitivity (GLUT-4, GLP-1, adiponectin). Thus, the results suggest that Lact. fermentum could act as potential probiotic for lifestyle-related disorders such as obesity, diabetes, and metabolic syndrome as both prophylactic and adjunct therapies.

Presence of extracellular DNA & protein in biofilm formation by gentamicin-resistant Lactobacillus plantarum

Background & objectives:

Bacterial biofilms a multi-layered defence, comprise extracellular DNA (eDNA) and proteins, protect bacteria from harmful environment and nutrient limitation and utilize the mutual benefits within a community. Bacterial biofilms also defend bacteria from harsh environments such as antibiotic treatment. This leads to poor antibiotic penetration, slow growth, adaptive stress responses, and formation of persister cells. This study was done to determine the relation of antibiotic resistance deciphered by the biofilms in Lactobacillus plantarum, a lactic acid bacteria (LAB) with probiotic significance.

Methods:

The gentamicin-resistant L. plantarum isolates were allowed to form biofilms and subjected to DNase I and proteinase K treatment. The optical density (OD) values were recorded for the biofilm assay and the cell count for the number of viable cells was taken for the control and the test samples. Percentage reduction was calculated based on the difference between the initial and final OD for both the parameters.

Results:

The biofilm assay revealed that the native L. plantarum isolates which were phenotypically susceptible, possessed the ability to form biofilms. The OD values were significantly decreased in comparison to the biofilm-forming control culture when these were treated with DNase I and proteinase K.

Interpretation & conclusions:

The study revealed that the biofilms formed by L. plantarum comprised of eDNA and proteins which was evidenced by the reduction in OD values and percentage in comparison to the control upon DNase I and proteinase K treatment. This indicates that the eDNA and biofilm matrix proteins are vital constituents of biofilms and may carry significant risk when coupled with antibiotic resistance.

Prophylactic effects of probiotic Bifidobacterium spp. in the resolution of inflammation in arthritic rats

In the present study, the modulatory effects of bifidobacterial spp. (Bifidobacterium breve NCIM 5671, Bifidobacterium longum NCIM 5672 and Bifidobacterium bifidum NCIM 5697) on adjuvant induced arthritis in rats were evaluated. Arthritis was induced in male Wistar rats by injecting 250 μg of Freund's adjuvant directly into the paw. Fifteen days before and 15 days after the induction of arthritis, suspended cultures of bifidobacteria (10⁹ cfu/ml) were administered by oral gavage. Paw volume, bone mineral content, oxidative stress markers, antioxidant enzymes, cytokines, eicosanoids and expression of COX2, as well as bone hydrolytic enzymes, were assessed by RT PCR. Although piroxicam-treated groups (drug control) had better effects than bifidobacteria-treated groups, bifidobacteria probiotics administration exhibited significant (P < 0.05) prophylactic effects in terms of downregulating arthritis markers. Parameters including paw volume, bone mineral content, cytokines, and eicosanoids level were significantly (p < 0.05) modulated in bifidobacteria administered groups compared to arthritic control group. Among the three strains tested, B. breve NCIM 5671 exhibited superior prophylactic effects as assessed in the experimental rat model of arthritis. In conclusion, bifidobacteria probiotics administration can downregulate the markers of arthritis and hence can be a potential therapeutic regimen in the treatment of arthritis.

In vitro adhesion and anti-inflammatory properties of native Lactobacillus fermentum and Lactobacillus delbrueckii spp

AIMS

This study aimed at characterizing the adhesion and immune-stimulatory properties of native probiotic Lactobacillus fermentum (MCC 2759 and MCC 2760) and Lactobacillus delbrueckii MCC 2775.

METHODS AND RESULTS

Adhesion of the strains was assessed in Caco-2 and HT-29 cell lines. Expression of adhesion and immune markers were evaluated in Caco-2 cells by real-time qPCR. The cultures displayed >80% of adhesion to both cell lines and also induced the expression of mucin-binding protein (mub) gene in the presence of mucin, bile and pancreatin. Adhesion was mediated by carbohydrate and proteinaceous factors. The cultures stimulated the expression of inflammatory cytokines in Caco-2 cells. However, pro-inflammatory genes were down-regulated upon challenge with lipopolysaccharide and IL-10 was up-regulated by the cultures. Cell wall extract of L. fermentum MCC 2760 induced the expression of IL-6 by 5·47-fold, whereas crude culture filtrate enhanced the expression of IL-10 by 14·87-fold compared to LPS control.

CONCLUSIONS

The bacterial cultures exhibited strong adhesion and anti-inflammatory properties.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report to reveal the role of adhesion markers of L. fermentum and L. delbrueckii by qPCR. The strain-specific anti-inflammatory property of native cultures may be useful to alleviate inflammatory conditions and develop a target-based probiotic.

Taming C-terminal peptides of Staphylococcus aureus leukotoxin M for B-cell response: Implication in improved subclinical bovine mastitis diagnosis and protective efficacy in vitro

Leukotoxin M/F'-PV (LukM/F'-PV) produced by bovine mastitis causing Staphylococcus aureus structurally comprises three domains, the β-sandwich, rim and stem domain. The rim and stem domains interacting with target cell membrane lipid rafts contributes to the virulent trait of the toxin. In the present study, two facts were hypothesized that neutralization of these domains will ebb LukM/F'-PV leukotoxicity. Secondly, the neutralizing antibodies can improve the leukotoxin detection sensitivity in bovine mastitis milk samples. The in silico mapping of S. aureus LukM C-termini comprising these domains predicted seven linear B-cell antigenic epitopes. The immune response of C-terminal truncated recombinant peptides rCtM19 (19 kDa; near carboxy-terminal) having four epitopes and rCtM15 (15 kDa; C-terminal) with three epitopes were evaluated for their diagnostic and neutralization potential. Anti-rCtM19 and anti-rCtM15 antibodies with enhanced immunogenicity had the most striking outcome in IgG-ELISA for detecting native determinants of leukotoxin. For the obtained ELISA values, ROC curve inferred a cut-off score of >0.102 OD405. The assay sensitivity in the range of 90-96% along with 100% specificity and AUC of 0.93-0.98 categorized subclinical and clinical from healthy bovine milk samples. As observed through in vitro neutralization and LDH assays, C-terminus specific antibodies (1:42 titer) deactivating leukotoxicity abolished LukM from interacting with lipid bilayer and LukF for forming pores on bovine neutrophil membrane. As a proof of concept, it was proved that peptide antibodies can be a more specific serodiagnostic and passive therapeutic molecules.

LACTOBACILLUS PLANTARUM MCC2034, A NOVEL ISOLATE FROM TRADITIONAL INDIAN LACTIC FERMENTED PREPARATION: MOLECULAR IDENTIFICATION AND EVALUATION OF ITS IN VITRO PROBIOTIC POTENTIAL

In the present study, the in vitro probiotic properties and molecular characterization (16S rRNA gene sequencing) of L. plantarum MCC2034, a lactic acid bacterium (LAB) isolated from Takrarista, traditionally used for the treatment of various gastro-intestinal maladies are presented. The isolate under study has been proved to be a potent producer of exopolysaccharide (EPS). The molecular identification of the strain was carried out using 16S rRNA gene sequencing method. The ability of the strain to survive the transit through the gastro-intestinal tract (GIT) was carried out using in vitro gastric system. Additionally, the in vitro adhesion property (viz. bacterial adhesion to hydrocarbon assay and autoaggregation) and bile salt hydrolase (BSH) activity of L. plantarum MCC2034 were carried out. Antibiotic resistance profile was determined using minimum inhibitory concentration (MIC) test against tetracycline, ampicillin, streptomycin, etc. The results of the in vitro probiotic characterization indicated that L. plantarum MCC2034 is capable of surviving the adverse conditions encountered during its passage through the GIT besides showing promise with respect to BSH and the antibiotic resistance profile also indicated that the strain is within the recommended limits. In conclusion, it can be stated that L. plantarum MCC2034, a Takrarista isolate capable of producing EPS, exhibited effective in vitro probiotic potential.

Extracellular chitin deacetylase production in solid state fermentation by native soil isolates of Penicillium monoverticillium and Fusarium oxysporum

Extracellular chitin deacetylase production by native soil isolates of Penicillium monoverticillium CFR 2 and Fusarium oxysporum CFR 8 in solid state fermentation (SSF) using commercial wheat bran (CWB) and shrimp processing by-products (SPP) as solid substrate has been studied. P. monoverticillium produced maximum chitin deacetylase activity of 547.7 ± 45 and 390.2 ± 31 units/g initial dry substrate (U/g IDS) at 96 h of incubation in CWB and SPP media, respectively. While, F. oxysporum produced maximum chitin deacetylase activity of 306.4 ± 22 U/g IDS at 72 h of incubation in CWB medium and 220.1 ± 20 U/g IDS at 120 h of incubation in SPP medium. Along with chitin deacetylase, P. monoverticillium and F. oxysporum produced other chitin degrading enzymes such as endo-chitinase and β-N-acetylhexosaminidase. P. monoverticillium produced maximum activity (U/g IDS) of endo-chitinase 4.6 ± 0.20 at 120 h incubation and β-N-acetylhexosaminidase 82.6 ± 03 at 120 h incubation in CWB medium. While, F. oxysporum produced maximum activity (U/g IDS) of endo-chitinase 7.8 ± 0.20 at 144 h incubation and β-N-acetylhexosaminidase 38.3 ± 02 at 120 h incubation in CWB medium. Production of extracellular chitin deacetylase by P. monoverticillium CFR 2 and F. oxysporum CFR 8 in SSF is being reported for the first time.

Antioxidant and anticoagulant activity of polyphenol and polysaccharides from fermented Sargassum sp

The current investigation was carried out with an objective of determining the structural characteristic of polysaccharides extracted from fermented Sargassum sp. to be used as potent natural heparin substitute anticoagulant compound. Sargassum sp. fermented with marine lactic acid bacteria was initially subjected to ethanol precipitation for the recovery of bioactive compounds. Antioxidant activity was maximum in the soluble fraction whereas anticoagulant activity was observed to be high in the precipitate which correlated with the increased polyphenols and total sugars respectively. The precipitate was purified by anion exchange chromatography and the fractions collected were analyzed for total sugars and anticoagulant activity. There was 2.6-3.9-folds increase in anticoagulant activity in the final purified fractions, with a maximum activity in case of sample fermented with Enterococcus faecium (6.7±0.22 IU/mg). Structural elucidation of potential anticoagulant polysaccharide by Fourier Transform Infrared Spectroscopy (FT-IR) and Nuclear Magnetic Resonance (NMR) analysis indicated the presence of alginate rich in mannuronic acid.

Immunogenicity of Staphylococcus aureus LukM/F'-PV recombinant subunits: validation of diagnostic potential and evaluation of protective efficacy in vitro

Leukotoxin M/F'-Panton Valentine (LukM/F'-PV), a beta pore-forming toxin secreted by Staphylococcus aureus, is a major virulence factor involved in the pathogenesis of bovine mastitis. The present study was aimed to determine immunogenicity of two recombinant subunits of LukM/F'-PV, rLukM (MW 38 kDa) and rLukF (MW 39 kDa), develop and validate an indirect enzyme linked immunosorbent assay (ELISA) using polyclonal antibodies raised in rabbits, and evaluate applicability of the assay to diagnose clinical and subclinical bovine mastitis. Additionally, in vitro assays were conducted to determine abilities of antibodies to neutralize cytotoxicity of the native leukotoxin. A total of 87 bovine milk samples (healthy, subclinical and clinical mastitis) were evaluated for the presence of toxin determinants. Receiver-operator characteristic curve for the experimental ELISA values statistically interpreted a cut-off score of >0.109 OD405, with an assay specificity of 100% and sensitivity in the range of 80-87.5%. In addition, area under curve of 0.93-0.98 revealed the test was accurate in categorizing samples from infected and non-infected bovine. The rLukF IgG-ELISA was more sensitive than rLukM IgG-ELISA. Furthermore, it was evident from MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium) dye reduction, indirect immunofluorescence and lactate dehydrogenase assays that anti-rLukM/rLukF antibodies, with high neutralizing titers, inhibited in vitro leukotoxic activity and protected bovine neutrophil membrane integrity from cytotoxicity of native leukotoxin. The findings demonstrated that antibodies produced from recombinant subunits contribute to specific and sensitive immunodiagnosis and may also have the potential to provide passive therapeutic benefit in the management of bovine mastitis.

Molecular Characterization and Toxicity Confirmation of LukM/F'-PV Producing Staphylococcus aureus Isolated from Bovine Mastitis Samples in Mysore, India

The widespread status of subclinical condition of bovine mastitis is often associated with the production of leukotoxin M/F'-PV producing Staphylococcus aureus. The present study aims for the profiling of such leukotoxin producers through conventional and molecular methods in parallel to their leukotoxicity. The incidence of this particular pathogen was assessed in mastitis infected Holstein-Friesian cattle, where eight isolates of staphylococci were found to be present in 20 % of collected samples. Being intermediately resistant to vancomycin, they showed characteristic double zone hemolysis on 7 % sheep blood agar and typical type II reaction for coagulase test indicating the pathogenic attributes. Further with RAPD-PCR and 16S rDNA-RFLP, epidemiological specificity and genotypic relatedness of isolates to S. aureus was confirmed. Subsequently, the presence of leukotoxin (lukM) gene in native isolates was detected by leukotoxin gene specific PCR. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium) assay evaluated for secreted leukotoxin in cell free supernatant was estimated to be 223 toxic units which had an LD50 cytotoxic activity on bovine neutrophil. Thus, the data acquired during study can be of prime diagnostic method for timely and accurate analysis of subclinical mastitis samples which goes undetected at consumer level.

Potential of marine lactic acid bacteria to ferment Sargassum sp. for enhanced anticoagulant and antioxidant properties

AIM

To evaluate the suitability of marine lactic acid bacteria (LAB) as starter cultures for Sargassum sp. fermentation to enhance its antioxidant and anticoagulation activity.

METHODS AND RESULTS

LAB isolated from marine source were characterized for their ability to utilize seaweed as a sole carbon source and applied to Sargassum fermentation. Fermentation period was optimized by monitoring the fermented sample at regular interval for a period of 18 days. Results revealed that a fermentation period of 12 days was effective with maximum culture viability and other desirable characteristics such as pH, total titratable acidity, total and reducing sugars. Under optimum fermentation period, the sample fermented with P1-2CB-w1 (Enterococcus faecium) exhibited maximum anticoagulation activity and antioxidant activity.

CONCLUSIONS

The study reveals a novel well-defined starter culture from marine origin intended for seaweed fermentation for recovery of bioactive molecules.

SIGNIFICANCE AND IMPACT OF THE STUDY

The study provides information for the enhancement of bioactive molecules in an eco-friendly manner and also paves a way towards the development of wide range of seaweed functional foods.

Phytate-degrading Pediococcus pentosaceus CFR R123 for application in functional foods

The present work looks at the role of phytate-degrading Pediococcus pentosaceus CFR R123 application in functional foods to evaluate the fate of phytate and calcium solubility during fermentation. Under standard conditions, CFR R123 grown in modified MRS containing sodium phytate CFR R123 showed 43% degradation of sodium phytate in 15 minutes. Fermentation of malted finger millet seed coat (MFSC) and soya milk (SM) with CFR R123 for 12 h resulted in 5.6-12% phytate degradation and a notable increase in calcium availability (125%) was observed. The isolate CFR R123 was found to decrease the phytic acid levels resulting in increased levels of calcium during MFSC and soya milk fermentation. This study introduces phytate-degrading P. pentosaceus CFR R123 that can be employed as a starter culture as well as an ingredient of functional food to provide nutritive benefits to the consumer with a natural phenomenon.

Characterisation of the heat-stable bacteriocin-producing and vancomycin-sensitive Pediococcus pentosaceus CFR B19 isolated from beans

A bacteriocin-producing lactic culture with antilisterial activity was isolated from beans and identified as Pediococcus pentosaceus CFR B19. It was able to grow and produce bacteriocin at 41 °C but not at 50 °C. This isolate was found to be sensitive to vancomycin and produced heat-stable (at 121 °C for 15 min) bacteriocin. Molecular weight of the purified bacteriocin was found to be ∼4.8 kDa. This isolate can be used as a starter culture or co-culture in fermented milk products and the bacteriocin can be used as a natural preservative in various food products.

Evaluation of beneficial attributes for phytate-degrading Pediococcus pentosaceus CFR R123

In this study we have screened and selected potent phytate-degrading lactic acid bacteria (LAB), and evaluated their beneficial attributes. Around 60 LAB strains were isolated from several cereal- and pulse-based conventional fermented preparations. They were screened for their ability to degrade myo-inositol hexakisphosphate (IP6) by cobalt chloride qualitative staining method (plate assay). One of the cultures, Pediococcus pentosaceus CFR R123, was capable of degrading both calcium and sodium salts of phytic acid. Additionally, we have carried out an in vitro evaluation for the beneficial attributes of phytate degrading CFR R123. P. pentosaceus CFR R123 showed 53% survivability at pH 2 and 62% at pH 2.5, whereas cultures of Lactobacillus rhamnosus GG showed a survivability of 55% and 82%, respectively. CFR R123 could also withstand 0.3% ox-bile, whereas no growth was observed for GG. The strain CFR R123 exhibited 62.8% hydrophobicity to xylene whereas 59% was found for GG. Both the tested strains showed a good spectrum of antibacterial activity against food-borne pathogens like Escherichia coli, Listeria monocytogenes Scott A, etc. P. pentosaceus CFR R123 possessed β-galactosidase activity and cholesterol reduction ability. In conclusion, LAB with phytate degrading ability and several beneficial attributes could potentially be used as a starter culture to improve the nutritional security of functional food.

Utilization of tannery fleshings: Optimization of conditions for fermenting delimed tannery fleshings using Enterococcus faecium HAB01 by response surface methodology

Conditions for fermentation of delimed tannery fleshings--to obtain higher degree of protein hydrolysis and reasonably better antioxidant activity--using Enterococcus faecium HAB01 (GenBank #FJ418568) were optimized. Three independent variables--viz., inoculum level (X1), glucose level (X2) and fermentation time (X3)--were optimized using response surface method considering degree of hydrolysis (DH; %) and total titrable acidity (TTA) as response variables. The optimized conditions were found to be 12.5% (v/w) inoculum, 17.5% (w/w) glucose and 96h of fermentation at 37+/-1 degrees C to obtain a maximum DH%. The usefulness of the predicted model was further validated by considering random combinations of the independent factors. The chemical score of the hydrolysate revealed an excess amount of essential amino acids, viz., arginine and leucine compared to reference protein. The liquor portion had relatively high antioxidant activities, indicating its potential for use as a high value feed ingredient.

Lactobacillus farciminis MD, a newer strain with potential for bacteriocin and antibiotic assay

A native isolate Lactobacillus farciminis MD isolated from fermenting mushroom exhibited a high degree of sensitivity to the majority of the bacteriocins produced by strains of lactobacilli, leuconostoc and pediococci. Also, the efficacy of Lact. farciminis MD as a sensitive strain for antibiotic assay was established against different antibiotics including ampicillin, cefazoline, chloramphenicol and nitrofurantoin at concentrations of 30 microg each, showing an inhibition zone of 30 mm diameter. The high degree of sensitivity towards bacteriocins and antibiotics provide potential for the exploitation of Lact. farciminis MD in establishing very well-defined bacteriocin producers.