Indigenous Lactobacilli Research Articles

Characterization of indigenous lactobacilli from dairy fermented foods of Haryana as potential probiotics utilizing multiple attribute decision-making approach

The interest in region-specific ethnic fermented foods and their functional microbiota is rising. The demands for functional foods are continuously rising, so research is going on to develop nutritious food with many beneficial attributes and low safety concerns. The present study was designed to isolate and characterize lactobacilli probiotic candidates from locally resourced fermented foods (dahi, lassi, and raabadi) to make ready-to-eat fermented functional products later. Cultures were isolated from 82 fermented food samples collected from different villages. The initial experiments of gram staining, catalase test, and carbohydrate fermentation were assessed for the morphology, purity, and primary characterization on the genus level, which was verified through molecular characterization using PCR. Seven lactobacilli strains (no. MS001-MS007) were then assessed for safety, probiotic candidacy, phytase degradation, and biofilm forming abilities. All seven bacterial cultures showed no hemolytic activity and antibiotic sensitivity against more than 14 antibiotics out of 20. All seven lactobacilli isolates were able to tolerate pH 3.0, 0.3% bile 0.5% pancreatin, lysozyme (100 mg/L to 300 mg/L) and also shown possessed phytase degradation ability. All the cultures showed antioxidative potential and biofilm formation ability. Culture MS007 showed considerably higher bile salt hydrolase activity among all the isolates, whereas MS005 possessed excellent phytate degradation ability among others. Bacterial strains were identified using 16S rRNA gene sequencing. Moreover, the order of preference of isolates was calculated using the multidimensional Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) based on probiotic and other functional properties. The most promising attributes showing cultures were recognised as Limosilactobacillus fermentum MS005 and Lactiplantibacillus plantarum MS007, which could be further used for functional food product development.Graphical

In vitro characterization of probiotic potential of Lactobacillus plantarum CM49 against selected cattle mastitogens

BackgroundBovine mastitis results in significant economic losses for the dairy industry globally due to milk production losses and decreased herd efficiency. This research aimed to isolate, select, and characterize indigenous lactobacilli with probiotic properties. A total of 40 lactobacilli were isolated from healthy milk samples of cattle and identified at the species level through 16S rDNA sequencing. All isolates were initially screened for antimicrobial activity, and selected isolates underwent in vitro assessment of probiotic properties.ResultsAmong the lactobacilli isolates, varying levels of activity (9 to 19 mm) against cattle mastitogens; Stapylococcus aureus (Staph. aureus), Escherichia coli (E. coli) and Streptococcus dysgalactiae (Strep. dysgalactiae) were observed in the well diffusion assay. These isolates demonstrated auto-aggregation (ranging from 14.29 ± 0.96% to 62.11 ± 1.09%) and co-aggregate (ranging from 9.21 ± 0.14% to 55.74 ± 0.74%) with mastitogens after 2 h. Lactobacillus (Lb.) plantarum CM49 showed sensitivity to most antibiotics tested and exhibited strong inhibitory effects, with mean log10 reductions of 3.46 for Staph. aureus, 2.82 for E. coli, and 1.45 for Strep. dysgalactiae in co-culture experiments. Furthermore, Lb. plantarum CM49 significantly decreased the adhesion rate of mastitogens on the bovine mammary cell line and mouse model, demonstrating its potential effectiveness in preventing mastitis.ConclusionIt is concluded that Lb. plantarum CM49 has remarkable probiotic potential with activity against cattle mastitogens in the laboratory and cell culture and competitively excludes mastitogens from bovine mammary cells and ameliorates Staph. aureus-induced mastitis in mice.

Probiotics and autoprobiotics for treatment of Helicobacter pylori infection.

The article discusses various approaches for probiotic treatment of Helicobacter pylori (H. pylori) infection: Probiotics as an adjuvant treatment in the standard eradication therapy; probiotic strains as a monotherapy; and autoprobiotics as a monotherapy. Autoprobiotics refer to indigenous bifidobacteria, lactobacilli, or enterococci isolated from a specific individual, intended to restore his/her microbiota and improve his/her health. The potential mechanisms of probiotic action against H. pylori include correction of the gut microbiota, immunological effects (enhancement of humoral and cellular immunity, and reduction of oxidative stress), direct antagonistic effects against H. pylori (such as colonization resistance and bacteriocin synthesis), and stimulation of local immunological protection (strengthening of the mucous protective barrier and reduction of gastric mucosa inflammation). The incorporation of probiotics into comprehensive eradication therapy shows promise in optimizing the treatment of H. pylori infection. Probiotics can enhance the eradication rates of H. pylori, reduce the occurrence and severity of side effects, and improve patient compliance. Probiotic or autoprobiotic monotherapy can be considered as an alternative treatment approach in cases of allergic reactions and insufficient effectiveness of antibiotics. We recommend including probiotics as adjunctive medications in anti-H. pylori regimens. However, further randomized multicenter studies are necessary to investigate the effects of probiotics and autoprobiotics against H. pylori, in order to gain a better understanding of their mechanisms of action.

In Vitro Characterization of Probiotic Potential of Limosilactobacillus fermentum against Salmonella Gallinarum Causing Fowl Typhoid.

Fowl typhoid, a septicaemic disease of poultry, is caused by Salmonella Gallinarum and leads to severe economic losses. The aim of the present study was to isolate, select and characterize indigenous probiotic lactobacilli with anti-Salmonella Gallinarum activity. A total 55 lactobacilli were isolated from the caeca and ileum parts of healthy chickens and identified to species level by 16S rDNA sequencing. All the isolates were initially screened for antimicrobial activity and selected isolates were further subjected to in vitro evaluation of probiotic properties. Lactobacilli isolates (n = 21) showed varying levels of activity (08-18 mm) against Salmonella Gallinarum. These selected isolates also showed tolerance to acidic conditions (pH 3 and 4). Out of these 21 isolates, 13 showed growth (>0.5 OD at 600 nm) 0.3% bile salts. Moreover, these isolates also had the ability of auto-aggregation (20.05 ± 0.62%-50.70 ± 1.40%), and co-aggregation with Salmonella Gallinarum (5.22 ± 0.21%-42.07 ± 0.70%). Results revealed that lactobacilli had a higher level of resistance to vancomycin (100%), streptomycin (100%), ciprofloxacin (95%), gentamicin (90%), doxycycline (90%), oxytetracycline (85%), and bacitracin (80%), and a lower level of resistance to penicillin (33%), erythromycin (28%), chloramphenicol (23%), fusidic acid (23%) and amoxicillin (4%). The Limosilactobacillus fermentum PC-10 and PC-76 were sensitive to most of the antibiotics. The overall results revealed that two Limosilactobacillus fermentum strains (PC-10 and PC-76) fulfill the in vitro selection criteria of probiotics, i.e, tolerance to low pH, resistance to bile salts, auto-aggregation, co-aggregation with Salmonella Gallinarum, and absence of acquired antibiotic resistance. The Limosilactobacillus fermentum PC-10 and PC-76 also inhibited the (>5 log10) growth of Salmonella Gallinarum in co-culture assay. It is concluded that Limosilactobacillus fermentum PC-10 and PC-76 may be further investigated and developed as anti-Salmonella Gallinarum probiotics for poultry.

Screening for Antifungal Indigenous Lactobacilli Strains Isolated from Local Fermented Milk for Developing Bioprotective Fermentates and Coatings Based on Acid Whey Protein Concentrate for Fresh Cheese Quality Maintenance.

The demand for healthy foods without artificial food additives is constantly increasing. Hence, natural food preservation methods using bioprotective cultures could be an alternative to chemical preservatives. Thus, the main purpose of this work was to screen the indigenous lactobacilli isolated from fermented cow milk for their safety and antifungal activity to select the safe strain with the strongest fungicidal properties for the development of bioprotective acid whey protein concentrate (AWPC) based fermentates and their coatings intended for fresh cheese quality maintenance. Therefore, 12 lactobacilli strains were isolated and identified from raw fermented cow milk as protective cultures. The safety of the stains was determined by applying antibiotic susceptibility, haemolytic and enzymatic evaluation. Only one strain, Lacticaseibacillus paracasei A11, met all safety requirements and demonstrated a broad spectrum of antifungal activity in vitro. The strain was cultivated in AWPC for 48 h and grew well (biomass yield 8 log10 cfu mL-1). L. paracasei A11 AWPC fermentate was used as a vehicle for protective culture in the development of pectin-AWPC-based edible coating. Both the fermentate and coating were tested for their antimicrobial properties on fresh acid-curd cheese. Coating with L. paracasei A11 strain reduced yeast and mould counts by 1.0-1.5 log10 cfu mL-1 (p ≤ 0.001) during cheese storage (14 days), simultaneously preserving its flavour and prolonging the shelf life for six days.

Probiotics in vaginal health.

Bacterial vaginosis, a type of vaginal inflammation, can be considered the main reason for abnormal discharges of the vagina and vaginal dysbiosis during reproductive years. Epidemiological investigations of females suffering from vaginitis demonstrated that at least 30% to 50% of all women had Bacterial vaginosis (BV). One of the fields of treatment is the use of probiotics, probiotics are commonly defined as viable microorganisms (yeasts or bacteria) that can positively affect the health of their hosts. They are used in foods, notably fermented milk products, and medicine-related products. The development of new probiotic strains is aimed at more active advantageous organisms. Lactobacillus species are the dominant bacteria in a normal vagina that can decrease the pH of the vagina by the production of lactic acid. A number of lactobacilli types can produce hydrogen peroxide as well. The presence of hydrogen peroxide-induced low pH can prevent the growth of several other microorganisms. The vaginal flora of BV cases can modify by replacing the Lactobacillus species with a high density of anaerobic bacteria (i.e. Mobiluncus sp. Bacteroides sp.), Mycoplasma hominis, and Gardnerella vaginalis. More vaginal infections are treated with medications, while there is a possibility of recurrence and chronic infection because of the adverse effects on the indigenous lactobacilli. Probiotics and prebiotics have shown capacities for optimizing, maintaining, and restoring the vaginal microflora. Therefore, biotherapeutics can offer alternative approaches to reduce infections of the vagina and thus promote consumers' health.

Characterization and evaluation of anti-Salmonella enteritidis activity of indigenous probiotic lactobacilli in mice.

Lactobacilli (n = 24), isolated from human infants and yogurt, showed variable in vitro activity against Salmonella enteritidis (8.0 ± 1.0 to 16.6 ± 0.5 mm) and other gut pathogens (9.0 ± 1.0 to 15.3 ± 0.5 mm), as determined by a well diffusion assay. The isolates were identified as Limosilactobacillus fermentum (FY1, FY3, FY4, IL2, and IL5), Lactobacillus delbrueckii (FY6 and FY7), Lactobacillus sp. (IL7), and Lactobacillus gasseri (IL12). All isolates showed variable in vitro tolerance to acidic pH for 3 h and visible growth at pH 4 and in the presence of 0.3% ox-bile. The antibiotic susceptibility profile of Lactobacillus isolates indicated resistance against vancomycin, ciprofloxacin, streptomycin, and lincomycin. Isolates had variable auto-aggregation and showed variable capabilities to co-aggregate with S. enteritidis. Based on all tested parameters, L. fermentum IL2, L. fermentum IL5, and L. gasseri IL12 were selected for co-culture experiments, followed by in vivo evaluation in Balb/c mice. All the selected isolates resulted in a 100% reduction in S. enteritidis in broth. Lactobacillus isolates efficiently colonized mouse guts and inhibited S. enteritidis colonization. Overall, there was ≥99.06% and ≤4.32 Mean log10 reduction in Salmonella counts in mice feces within 7 days. The study, thus, provided characterized lactobacilli that could be considered as potential ingredients for probiotic formulations intended to prevent S. enteritidis infection in humans.

In-vitro evaluation of indigenous probiotic lactobacilli for lead bio-adsorption potential, its tolerance and complex stability

Probiotic lactic acid bacteria exhibit metal ion binding properties, which can be employed as metal bio-adsorbents in the human system. Lead is a prevalent dietary contaminant that causes lead toxicity in humans, especially children. In the present investigation, we evaluated the indigenous lactobacilli for their lead bioadsorption potential that can offer a pre-emptive approach for bioremediating lead toxicity. After standardizing the lead bioadsorption assay, ten probiotic lactobacilli showing lead retention of >80% in the pellet were selected. Statistical correlation analysis on lead bioadsorption assay, factors affecting lead and lead resistance profiling revealed L. plantarum HD 51 as the most potent lead adsorber. Scanning electron microscopy of L. plantarum HD 51 demonstrated that the binding occurred on the bacterial cell wall. Hence L. plantarum HD-51 could be used as a biotherapeutic agent to reduce the body’s burden on lead by sequestering it out of the human body.

Growth of ɣ-Proteobacteria in Low Salt Cucumber Fermentation Is Prevented by Lactobacilli and the Cover Brine Ingredients.

ABSTRACTThis study investigated the ability of ɣ-proteobacteria, indigenous to fresh cucumber, to grow in the expressed fruit juice (CJM) and fermentation. It was hypothesized that fresh cucumbers can support prolific growth of ɣ-proteobacteria but that the cover brine composition and acid production by the competing lactobacilli in the fermentation of the fruit act as inhibitory agents. The ɣ-proteobacteria proliferated in CJM with an average maximum growth rate (μmax) of 0.3895 ± 0.0929 and doubling time (Td) of 1.885 ± 0.465/h. A significant difference was found between the ɣ-proteobacteria μmax and Td relative to Lactiplantibacillus pentosus LA0445 (0.2319 ± 0.019; 2.89/h) and Levilactobacillus brevis 7.2.43 (0.221 ± 0.015; 3.35/h) but not Lactiplantibacillus plantarum 3.2.8 (0.412 ± 0.119; 1.87/h). While inoculation level insignificantly altered the μmax and Td of the bacteria tested; it impacted the length of lag and stationary phases for the lactobacilli. Unlike the lactobacilli, the ɣ-proteobacteria were inhibited in CJM supplemented with a low salt fermentation cover brine containing calcium chloride, acetic acid and potassium sorbate. The ɣ-proteobacteria, P. agglomerans, was unable to proliferate in cucumber fermentations brined with calcium chloride at a pH of 6.0 ± 0.1 and the population of Enterobacteriaceae was outcompeted by the lactobacilli within 36 h. Together these observations demonstrate that the prolific growth of ɣ-proteobacteria in CJM is not replicated in cucumber fermentation. While the ɣ-proteobacteria growth rate is faster that most lactobacilli in CJM, their growth in cucumber fermentation is prevented by the cover brine and the acid produced by the indigenous lactobacilli. Thus, the lactobacilli indigenous to cucumber and cover brine composition influence the safety and quality of fermented cucumbers.IMPORTANCE While the abundance of specific ɣ-proteobacteria species varies among vegetable type, several harbor Enterobacteriaceae and Pseudomonadaceae that benefit the plant system. It is documented that such bacterial populations decrease in density early in vegetable fermentations. Consequently, it is assumed that they do not contribute to the quality of finished products. This study explored the viability of ɣ-proteobacteria in CJM, used as a model system, CJM supplemented with fermentation cover brine and cucumber fermentation, which are characterized by an extremely acidic endpoint pH (3.23 ± 0.17; n = 391). The data presented demonstrates that fresh cucumbers provide the nutrients needed by ɣ-proteobacteria to proliferate and reduce pH to 4.47 ± 0.12. However, ɣ-proteobacteria are unable to proliferate in cucumber fermentation. Control of ɣ-proteobacteria in fermentations depends on the cover brine constituents and the indigenous competing lactobacilli. This knowledge is of importance when developing guidelines for the safe fermentation of vegetables, particularly with low salt.

The Probiotic Properties of Lactobacilli in Organic Pigs

Indigenous Lactobacilli are suitable probiotics because they adapt well in the hosts and ecological niches. Here we test local Lactobacillus for future application in the pigs as the farm-autogenous strains. The objectives of this study were to evaluate the probiotic properties of Lactobacillus isolated from the feces of antibiotic-free organic pigs. The properties include bile salt and pepsin tolerance, survival in storage (37 & 4 o C) and probiotic-packaging (50 o C) temperatures, antibiogram, and antagonistic activity against Salmonella typhimurium ATCC 13311 and Escherichia coli ATCC 25922. Eighteen isolates with three different species were tested in this study as follows: L. reuteri (seven strains), L. mucosae (ten strains), and L. plantarum (one strain). Four isolates— L. reuteri -OP1, L. mucosae -OP2, L. mucosae -OP3, and L. reuteri -OP17—had good in vitro probiotic characteristics. Eleven isolates completely inhibited both E. coli and S. typhimurium . The other isolates are perfectly disabled, either E. coli or S. typhimurium . Despite that, they caused a reduction in the numbers of each pathogen. All Lactobacilli tested were susceptible to amoxicillin-clavulanate, ampicillin, and imipenem. Most isolates were sensitive to clindamycin (72%), gentamicin (56%), and tetracycline (50%). Half of the proportions were somewhat sensitive/resistant to cefotaxime (39/44%), tetracycline (50/39%), and streptomycin (39/56%). One hundred percent of Lactobacilli were resistant to norfloxacin, sulfamethoxazole-trimethoprim, and vancomycin, while 94% were resistant to enrofloxacin. Most of the local Lactobacilli passed in vitro tests, but the efficacy of probiotics in pigs awaits further in vivo investigation. Therefore, the potential probiotic strains derived from this study could be selected for further evaluation of their probiotic roles in economic pigs.

Impacts of Prebiotic-Supplemented Diets and Breastmilk on Population and Diversity of Lactobacilli Established in Thai Healthy Infants.

The relative abundance and diversity of lactobacilli present in feces of infants fed with breastmilk and fructooligosaccharide-galactooligosaccharide (FOS-GOS)-, and inulin-galactooligosaccharide (inulin-GOS)-supplemented infantformulae and combination of both were compared. Fecal lactobacilli rapidly colonized and reached maximum total cell counts, which were significantly higher in the infants fed by combining breastmilk with a formula containing either FOS-GOS (C1-A infant) or inulin-GOS (C2-C infant) and the exclusively formula fed ones (F1-F and F2-H infants) than those detected in the exclusively breast-fed (B1-D and B2-E infants) (P < 0.05). The greatest relative abundance of fecal lactobacilli species was observed in all infant receiving prebiotic-containing diets, whereas bifidobacteria appeared predominantly in exclusively breast-fed infants. The species composition of lactobacilli was highly unique among individual and more variable in both groups of infants receiving breastmilk than the exclusively formula-fed infants. Breastmilk seem to be a great source of indigenous lactobacilli vertically transferred and continuously seeded infants' gut. Meanwhile, prebiotic supplementation in infant formulae enhanced and sustained the successful colonization of lactobacilli.

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The Need to Focus on Therapy Instead of Associations.

Molecular analyses of the vaginal microbiota have uncovered a vast array of organisms in this niche, but not so far changed what has been known for a long time: lactobacilli are dominant in health, and the diagnosis and treatment of symptomatic bacterial vaginosis is sub-optimal, and has not changed for over 40 years. While the lowering cost of DNA sequencing has attracted more researchers to the field, and bioinformatics, and statistical tools have made it possible to produce large datasets, it is functional and actionable studies that are more urgently needed, not more microbial abundance, and health or disease-associative data. The triggers of dysbiosis remain to be identified, but ultimately treatment will require disrupting biofilms of primarily anaerobic bacteria and replacing them with the host's own lactobacilli, or health-promoting organisms. The options of using probiotic strains to displace the biofilms and for prebiotics to encourage resurgence of the indigenous lactobacilli hold great promise, but more researchers need to develop, and test these concepts in humans. The enormity of the problem of vaginal dysbiosis cannot be understated. It should not take another 40 years to offer better management options.

Biological Properties and Probiotic Potential of Intestinal Lactobacilli

Data on inefficiency in some cases or temporary positive effect of commercial probiotics led to the development of the concept of autoprobiotic therapy. According to this, the correction of disturbed microbiocenoses is carried out using autostrains of indigenous normal flora (bifidobacteria, lactobacilli and enterococci). However, publications about effectiveness of autoprobiotic therapy are few and contradictory.The aimof the study was to investigate the biological properties and probiotic potential of intestinal lactobacilli, as well as the effectiveness of autoprobiotic therapy, based on Lactobacillus spp.Methods.Biological properties (antibiotic resistance, hemolytic, adhesive and antagonistic activity) were studied in 159 strains of intestinal lactobacilli. Autoprobiotic therapy with sour-milk ferments based on lactobacilli autostrains was carried out in 78 patients of the of the North Caucasus Federal District (NCFD) hospitals to correct the microbiocenosis of the large intestine due to antibiotic therapy.Results.The indigene strains of the intestinal lactobacilli of patients of NCFD hospitals are characterized by a wide spectrum of antibiotic sensitivity, lack of hemolysin production, medium adhesiveness and a high degree of antagonistic activity. Autoprobiotic therapy using Lactobacillus spp. significantly increases the amount of lactobacilli of the large intestine of patients in hospitals of the North Caucasian Federal District.Conclusion.A high probiotic potential of the indigenous intestinal lactobacilli is identified, which makes it possible to use them as effective autoprobiotics. The effectiveness of autoprobiotics with fermented milk starters with Lactobacillus spp. has been proven to restore the normal amount of intestinal lactobacilli patients after the use of broad-spectrum antibiotics.

Role of inulin as prebiotics on inflammatory bowel disease.

The present review is focused on the prebiotic impact of inulin on the management of the gastrointestinal disorder. Prebiotics can be described as "non-digestible food ingredient stimulating the growth of a certain number of bacteria in the colon, which can improve the host health". In 2004 this definition was modernized to include other areas that may benefit from selective targeting of particular microorganisms: "selectively fermented ingredients that alter the configuration and activity in the gastrointestinal microbiota that confer positive effect". The positive impact of prebiotics in experimental colitis and human inflammatory bowel disease (IBD) has already been established. Prebiotics shows a positive effect in the prevention of IBD by modulating the trophic functions of the flora. Inulin enhances the growth of indigenous lactobacilli and/or bifidobacteria by inducing colonic production of short chain fatty acids (SCFA's) and these properties are related to decreased mucosal lesion scores and diminished mucosal inflammation. Inulin shows a positive approach to retain microbial populations and to support epithelial barrier function by their prebiotic effect which helps in the host defense against invasion and pathogens translocation (endogenous and/or exogenous) and in the inhibition of gastrointestinal diseases and this impact should be verified in further clinical studies. In the present review, we discussed the positive effect of prebiotics in rat IBD models and in human subjects along with their potential protective mechanisms. Preclinical and clinical data revealed that the gut mucosal barrier would be improved by the use of prebiotics in IBD.

Разработка метода идентификации индигенных лактобацилл кишечника при создании аутопробиотиков

Разработка метода идентификации индигенных лактобацилл кишечника при создании аутопробиотиков

Susceptibility of gut indigenous lactic acid bacteria in BALB/c mice to oral administered Lactobacillus plantarum

Cells of Lactobacillus plantarum strains AN1 and Tennozu-SU2 exert anti-inflammatory responses in ICR mouse models of inflammatory bowel disease and protective effects against S. Typhimurium infection in BALB/c mice, respectively. To clarify the existence of L. plantarum-susceptible gut indigenous bacteria, AN1 and Tennozu-SU2 cells were administered to BALB/c mice via drinking water. Gene amplicon sequencing of 16S rRNA of caecal content revealed that the AN1 and Tennozu-SU2 cells affected the abundance of caecal indigenous lactobacilli, but the effect on the dominant Clostridiales and Bacteroidales was not clear. With Blood and Liver (BL) agar containing 5% v/v horse blood, six typical colonies from faecal samples were detected as the principal lactobacilli. Among them, two typical colonies were isolated and identified to be AN1 and Tennozu-SU2. Two and one typical colonies detected in all mice were identified to be L. reuteri and L. murinus, respectively. The other one was identified and estimated to be indigenous L. plantarum detected in the Tennozu-SU2 group.

In Vitro Screening of Indigenous Lactobacillus Isolates for Selecting Organisms with Better Health-Promoting Attributes.

Lactobacilli have several attributes that provide health benefits to the host. The aim of this study was to screen indigenous lactobacilli from human gut and fermented foods for such attributes as production of β- and α-galactosidase and also their ability to reduce serum cholesterol. Lactobacilli were cultured on MRS broth and β-galactosidase activity was determined using o-nitrophenyl-β-D-galactopyranoside (ONPG) as a substrate. Three isolates Lactobacillus fermentum GPI-3 and L. fermentum GPI-6 and Lactobacillus salivarius GPI-1(S) showed better β-galactosidase activity than the standard strains Lactobacillus rhamnosus GG (LGG) and Lactobacillus plantarum ATCC 8014. The isolates showed variability in assimilating cholesterol during growth. Several isolates showed excellent cholesterol-lowering ability compared to standard strains LGG and L. plantarum ATCC 8014. Isolate L. rhamnosus SCB being the highest acid producer (pH4.38) also showed the highest cholesterol reduction compared to other strains including standard strains. The ability of these isolates to produce α-galactosidase was also studied and the maximum α-galactosidase activity was found in isolate L. salivarius GPI-1(S) followed by L. fermentum FA-5 and Lactobacillus helveticus FA-7. This study therefore reports Lactobacillus isolates that have superior probiotic properties when compared to the standard strains; hence, they could be considered as potential probiotic strains, which can provide health benefits to the Indian population.

α-Galactosidase activity and oligosaccharides reduction pattern of indigenous lactobacilli during fermentation of soy milk

Abstract Soy milk, a water extract of soybean, can provide a plentiful and inexpensive supply of proteins. Besides, other nutritive components such as lipids, vitamins, minerals, isoflavones, flavonoids, saponins, and bioactive peptides found in soy milk are known to have therapeutic values. Conversely, the presence of indigestible oligosaccharides and beany flavor have limited the wide consumption of soy milk. α-Galactosidase enzyme are known to hydrolyze these flatulence causing oligosaccharides. In this context, this study evaluated the α-galactosidases production potential and oligosaccharides reduction pattern of six Lactobacillus isolates during growth in soy milk. All the strains were efficiently grown in soy milk with viable count ranging from 5.7 to 10.4 Log10 cfu/ml during 24 h of fermentation. All the strains were found proteolytic in nature represented varied degree of proteolysis at each fermentation step investigated. The highest proteolysis was observed by LR C34 (638.56 ± 7.9 µg serine/ml) after 24 h of fermentation. Among studied Lactobacillus strains LR C8 displayed highest cumulative α-galactosidases activity between 6 and 18 h of incubation. Correspondingly, the highest utilization of sucrose and stachyose was also showed by LR C8. Overall, sucrose and raffinose were reduced maximum upto 24 h of fermentation in comparison to stachyose by studied lactobacilli. Interestingly, more than 90% reduction in stachyose given by LR C8 was significantly higher (P

Evaluation of probiotic and prebiotic-like effects of Bacillus subtilis BN on growth of lactobacilli.

The aim of this study was to determine the probiotic and the prebiotic-like properties of Bacillus subtilis BN, a spore-forming bacterium, also known as "natto-kin", which is used for making the Japanese fermented food, natto. We used the spores and vegetative cells of this strain and compared their effects on the growth of lactobacilli. Culture supernatant from B. subtilis BN was added to a glucose-free MRS medium used to culture lactobacilli. When lactobacilli were cultured in the supernatant-containing medium, growth was improved. This effect resulted from the digestion of starch by amylase, which was secreted by B. subtilis. Moreover, improved amylase-independent growth was also observed. Co-culture with B. subtilis improved the growth of lactobacilli, and this effect was only observed with vegetative cells; spores did not improve the growth of lactobacilli. This effect on growth was lost upon heat treatment of the vegetative cells. These results suggest that the surface protein of B. subtilis BN vegetative cells participates in the improved growth effect of lactobacilli. It is possible that B. subtilis BN could improve the intestinal flora. In addition, B. subtilis BN inhibited the growth of Salmonella enterica. Thus, it was shown that B. subtilis BN has both a probiotic and prebiotic potential. This is the first study demonstrating the selective growth improvement of indigenous intestinal lactobacilli using B. subtilis BN.