Potential Of Lactic Acid Bacteria Research Articles

In Vitro and In Vivo Cholesterol Reducing Ability and Safety of Probiotic Candidates Isolated from Korean Fermented Soya Beans

Hypercholesterolemia is a risk factor for cardiovascular diseases, and hence, reducing serum cholesterol levels could reduce the incidence. In this study, we ascertained the cholesterol-reducing potential of lactic acid bacteria (LAB) isolated from Korean fermented soybean paste. Live, resting, and dead cells of all the bacteria reduced cholesterol in liquid media in a strain-dependent manner. Live cells of Weissella cibaria SCCB2306, Pediococcus acidilactici SDL1402, P. acidilactici SDL1406, and Lactobacillus rhamnosus JDFM6 reduced the most cholesterol in liquid media by 78 ± 3%, 72 ± 3%, 76 ± 3%, 75 ± 5%, and 79 ± 2%, respectively. As the cholesterol levels in the media reduced, cell membrane lipids of P. acidilactici SDL1402, P. acidilactici SDL1406, and L. rhamnosus JDFM6 increased by 23.36mg/mL, 6.53mg/mL, and 8.14mg/mL, respectively, indicating that cholesterol was incorporated into the bacteria cell membranes. All the bacteria displayed bile salt hydrolase activities in a strain-dependent manner. Though all four LAB significantly reduced cholesterol levels in Caenorhabditis elegans irrespective of the order of feeding, L. rhamnosus JDFM6 reduced the most cholesterol in vivo (up to 40% of ingested cholesterol). None of the four LAB hydrolyzed mucin or gelatin and none was toxic to C. elegans. The concentrations of phenylethylamine, putrescine, cadaverine, histamine, and tyramine produced by the LAB were below the toxic limits of biogenic amines set by the European Food Safety Authority. Taken together, our results demonstrate that Weissella cibaria SCCB2306, P. acidilactici SDL1402, P. acidilactici SDL1405, and L. rhamnosus JDFM6 could be safe cholesterol-reducing probiotic candidates for preventing or managing hypercholesterolemia.

Potential of lactic acid bacteria in biocontrol of Aspergillus niger, Penicillium chrysogenum and Fusarium graminearum in culture media and natural substrate

Potential of lactic acid bacteria in biocontrol of Aspergillus niger, Penicillium chrysogenum and Fusarium graminearum in culture media and natural substrate

Bioactivities and ACE-inhibitory peptides releasing potential of lactic acid bacteria in fermented soy milk

This study was designed to evaluate the bioactivities such as β-glucosidase activity, α-galactosidase activity, and the growth behavior of the Lactobacillus cultures in soy milk medium. Ten Lactobacillus cultures were considered in this study. L. fermentum (M2) and L. casei (NK9) were selected due to their better α-galactosidase, β-glucosidase activity and growth behavior in soy milk medium during fermentation. Further, soy milk fermented with M2 showed higher proteolytic activity (0.67 OD) and ACE-inhibitory (48.44%) than NK9 (proteolytic activity: 0.48 OD and ACE-inhibitory activity: 41.33%). Bioactive peptides produced during the fermentation of soy milk using the selected Lactobacillus cultures were also identified with potent ACE-inhibitory activity by MALDI-TOF spectrometry, and the identified ACE inhibitory peptide sequences from fermented soy milk were characterized using Biopep database.Graphical abstract

Isolation, Characterization and Identification of Lactic Acid Bacteria as Probiotic

Lactic acid bacteria that grow as the adventitious microflora of foods or that are added to foods as cultures are generally considered to be harmless or even an advantage for human health. The objective of this study was to isolate, screen and identify lactic acid bacteria from different sources. As well, evaluate the more potent lactic acid bacteria isolates for their probiotic characteristics. Ninety-six bacterial isolates were isolated from different 18 sources, 51 (53%) isolates were able to hydrolyze 0.5% bile salts while 28 isolates were able to hydrolyze 1% bile salts. Also, only 11 isolates were able to tolerate 2% bile salts after 6h incubation periods. On the other hand, lactic acid bacteria isolates were able to survive at pH 1.5 and 3.0 as well 8.0. Also, these isolates were potent for cholesterol assimilation, NaCl tolerance, exopolysaccharides production, antioxidant activity. Lactic acid bacteria isolate MS87 that exhibited excellent probiotic characteristics was identified using 16S rRNA sequence as Pediococcus pentosaceus. This study led to suggest that environmental-derived lactic acid bacteria-strains could be used as a potential source of probiotic.

Antimicrobial Activity of Lactic Acid Bacteria Found in Dadiah on Disease-Causing Skin Infections

Dadiah is a fermented food made from buffalo milk containing lactic acid bacteria (LAB). The potentialof LAB as an antimicrobial organism is expected to inhibit or kill pathogens, especially those causinginflammations in the skin. Dadiah used in this study was obtained from the Lintau area of Tanah DatarDistrict, West Sumatra, Indonesia. LAB isolation and identification involved the use of MRS Broth(MERCR) and MRS Agar (MERCK) media and the pathogenic bacteria used include Staphylococcusaureus, Propionibacterium acnes, Acinetobacter Baumannii, Klebsiella pneumonia, and Pseudomonasaeruginosa. The results of this study obtained a total LAB of 7x1011 CFU / g and showed the highestantimicrobial activity in the Staphylococcus aureus with a14.53 mm clear zone and 13.18 mm bacteria inthe Pseudomonas aeruginosa test bacteria.

Antilisterial Potential of Lactic Acid Bacteria in Eliminating Listeria monocytogenes in Host and Ready-to-Eat Food Application

Listeriosis is a severe food borne disease with a mortality rate of up to 30% caused by pathogenic Listeria monocytogenes via the production of several virulence factors including listeriolysin O (LLO), transcriptional activator (PrfA), actin (Act), internalin (Int), etc. It is a foodborne disease predominantly causing infections through consumption of contaminated food and is often associated with ready-to-eat food (RTE) and dairy products. Common medication for listeriosis such as antibiotics might cause an eagle effect and antibiotic resistance if it is overused. Therefore, exploration of the use of lactic acid bacteria (LAB) with probiotic characteristics and multiple antimicrobial properties is increasingly getting attention for their capability to treat listeriosis, vaccine development, and hurdle technologies. The antilisterial gene, a gene coding to produce antimicrobial peptide (AMP), one of the inhibitory substances found in LAB, is one of the potential key factors in listeriosis treatment, coupled with the vast array of functions and strategies; this review summarizes the various strategies by LAB against L. monocytogenes and the prospect in development of a ‘generally regarded as safe’ LAB for treatment of listeriosis.

Lactic acid bacteria prevent both periodontitis and atherosclerosis exacerbated by periodontitis in spontaneously hyperlipidemic mice.

Recent studies have shown a link between periodontal disease and cardiovascular disease. We have previously reported that oral administration of Porphyromonas gingivalis (Pg) accelerates atherosclerosis in apolipoprotein E-deficient spontaneously hyperlipidemic (Apoeshl ) mice. This study evaluated the potential of lactic acid bacteria (LAB) to change the intestinal flora changes induced by periodontopathic bacteria and to prevent/slow down the development of atherosclerosis. Lactobacillus gasseri O3-2 (Lg) was orally intubated in Apoeshl mice for 5weeks. Three weeks after oral intubation, the mice were orally infected with Pg for 2weeks. Thirty days after the last infection with Pg, Lg+Pg-treated mice showed a significant reduction in alveolar bone loss compared to the Pg-treated group. The Lg treatment restored the Pg-induced intestinal flora disturbance to normal. Furthermore, a significant decrease in atherosclerotic plaque lesion size and suppressed inflammatory cytokine production in the aorta were detected in the Lg+Pg-treated group. In contrast, blood concentrations of TMAO, histidine, and carnitine were enhanced by the Lg treatment but decreased by Lg+Pg treatment. These results suggest that oral Lg treatment is effective in preventing periodontitis and atherosclerosis.

A new probiotic candidate bacterium from human milk: Limosilactobacillus vaginalis MA-10

AbstractThe probiotic and technological potentials of lactic acid bacteria originating from human milk are becoming a remarkable research area. In the present study, Limosilactobacillus vaginalis MA-10 isolated from human milk was investigated in vitro for its probiotic and technological aspects. According to the results obtained in the study, MA-10 strain exhibited non-haemolytic activity and various degrees of sensitivity to most of the tested antibiotics. The strain showed good resistance to the gastrointestinal system and maintained its viability under these conditions. Its antimicrobial activity against human or clinical bacterial and fungal microorganisms and fish bacteria was determined in the range of 2.38–11.22 mm. The MA-10 strain was able to assimilate cholesterol ranging from 31.42 to 82.30%. The strain showed 9.34% ferrous-ion chelating and 32% DPPH free radical scavenging activities. These initial results from the present study confirm that L. vaginalis MA-10 may be a new source with appropriated probiotic and technological traits for various industries, and further in vivo assays.Due to the limited number of studies on L. vaginalis strains originated from human breast milk in the literature, the data obtained in this study are thought to be important for revealing the basic probiotic properties of the strain.

Potential of Lactobacillus strains for the production of fermented functional beverages enriched in galacto-oligosaccharides

Galacto-oligosaccharides (GOS) are prevalent prebiotic ingredients of various functional foods. GOS synthesis by β-galactosidase from whey-derived lactose results in a crude GOS mixture containing additionally lactose, glucose and galactose. In this study, we assessed the potential of lactic acid bacteria for depleting non-GOS sugars from crude GOS by selective fermentation. We aimed to combine the prebiotic characteristics of purified GOS with the health promoting effects of lactic acid fermentation metabolites. Our results indicated that supplementation of crude GOS with casein hydrolysate and retardation of acidification during fermentation stimulated cell growth, mono- and disaccharide consumption, overall organic acid production and diversity of the produced acids. Fermentation performed by Lactobacillus paracasei PB9 and L. plantarum 2108 resulted in lactic and citric acid containing high purity GOS media with a final pH below 4.6. We assessed the products as nutritionally safe that open a way to the formulation of prebiotic fermented beverages. Moreover, lactic fermentation of crude GOS would offer an alternative to the end-to-end valorization of whey-derived lactose.

Metataxonomic analysis of microbiota from Pakistani dromedary camelids milk and characterization of a newly isolated Lactobacillus fermentum strain with probiotic and bio-yogurt starter traits.

This study was undertaken to investigate the starter and probiotic potential of lactic acid bacteria isolated from dromedarian camel's milk using both culture-dependent and -independent approaches and metataxonomic analysis. Strains of lactic acid bacteria recovered were examined in vitro for tolerance to gastric acidity, bile, and lysozyme. Bile salt hydrolysis, serum cholesterol-lowering, oxalate degradation, proteolytic activity, exopolysaccharide production, and cell surface characteristics necessary for colonizing intestinal mucosa were also evaluated. A single strain of the species, Lactobacillus fermentum named NPL280, was selected through multivariate analysis as it harbored potential probiotic advantages and fulfilled safety criteria. The strain assimilated cholesterol, degraded oxalate, produced exopolysaccharides, and proved to be a proficient alternate yogurt starter with good viability in stored bio-yogurt. A sensorial analysis of the prepared bio-yogurt was also found to be exemplary. We conclude that the indigenous L. fermentum strain NPL280 has the desired traits of a starter and adjunct probiotic culture for dairy products.

Evaluation of the probiotic and postbiotic potential of lactic acid bacteria from artisanal dairy products against pathogens.

Probiotic and postbiotic potential of thirty-two strains of lactic acid bacteria (LAB), obtained earlier from artisanal dairy sources in Pakistan, have been investigated against major multi-drug resistant (MDR) and food borne pathogenic bacteria. LAB strains were identified by 16S rRNA gene sequencing and their antibacterial activity was assessed by the microdilution method. Four LAB isolates, Weissella confusa PL6, Enterococcus faecium PL7, and Lactobacillus delbrueckii PL11 and PL13 were shortlisted. Their ability to degrade lactose and safety for human consumption in terms of hemolysis and antibiotic susceptibility were assessed in vitro. The antibacterial components in the cell-free supernatants (CFSs) of isolate cultures were characterized biochemically by HPLC. Acid neutralization but not protease treatment abolished the antibacterial activity of CFSs. Lactic, acetic and propionic acids were the main acids in the CFSs, and acid production peaked in the stationary phase of growth. The antibacterial activity of the LAB cultures resulted from secretion of organic acids that lowered the pH. The strains exhibited variable ability to degrade lactose and were non-hemolytic and susceptible to the most common antibiotics. These LAB strains are probiotic candidates for further investigation of their postbiotic role in naturally preserving processed foods and for attenuation of lactose intolerance.

Assessment of the bioprotective potential of lactic acid bacteria against Listeria monocytogenes in ground beef.

Lactic acid bacteria can be considered as natural biopreservative and good biotechnological alternative to food safety. In this study, the antilisterial compounds produced by Enterococcus isolates from the Patagonian environment and their effectiveness for the control of Listeria monocytogenes in a food model were studied. Enterococcus isolates whose cell-free supernatant presented activity against Listeria monocytogenes were identified and evaluated for their virulence factors. The activity of the antimicrobial compounds produced by Enterococcus sp. against Listeria monocytogenes Scott A in meat gravy and ground beef during refrigerated storage was tested. The results indicated that ten Enterococcus isolates presented activity against Listeria monocytogenes and none of the selected strains presented virulence factors. L. monocytogenes in the food models containing the antilisterial compounds produced by Enterococcus sp. has decreased over the days, indicating that these compounds and cultures are an alternative to control the growth of L. monocytogenes in foods.

Isolation, identification and potential probiotic characterization of lactic acid bacteria from Thai traditional fermented food.

The probiotic potential of lactic acid bacteria (LAB) isolated from Thai traditional fermented food was investigated. Forty-two samples were collected from four markets in Phra Nakhon Si Ayutthaya Province. Out of 50 isolated LAB, 6 (a3, f4, f8, K1, K4 and K9) obtained from pla-ra and bamboo shoot pickle samples showed high tolerance to gastrointestinal tract conditions. These isolates were selected to identify and characterize their probiotic properties. Isolate a3 was identified as Weissella thailandensis, isolates f4 and f8 were identified as belonging to Enterococcus thailandicus and isolates K1, K4 and K9 were determined as Limosilactobacillus fermentum. All six LAB exhibited high autoaggregation ability (93.40–95.01%), while W. thailandensis isolate a3 showed potential for coaggregation in almost all the pathogenic bacteria tested. Cell-free supernatant (CFS) obtained from all isolates did not inhibit Staphylococcus aureus. CFS derived from L. fermentum isolate K4 showed the most efficient antimicrobial activity, in particular against Gram-negative bacteria, while L. fermentum isolate K4 presented high surface hydrophobicity in the presence of xylene and n-hexane. All LAB isolates were found to be resistant to clindamycin and nalidixic acid, whereas E. thailandicus isolate f8 exhibited resistance to most of the antibiotics tested. L. fermentum isolate K4 showed promise as a suitable probiotic candidate for future applications in the food industry due to tolerance to gastrointestinal tract conditions with high surface hydrophobicity and inhibited most of the pathogens tested.

Characterization and probiotic potential of lactic acid bacteria isolated from dadiah sampled in West Sumatra

Dadiah is a traditional dairy food from West Sumatra. Dadiah is made by fermenting fresh buffalo milk in banana leaves covered bamboo sticks at room temperature for two days. Dadiah is nutritious because it contains lactic acid bacteria (LAB) that have probiotic properties. This study aims to determine the characteristics and biochemical properties of LAB by catalase assay and fermentation type. We identified the LAB found in dadiah using conventional laboratory tests and 16S rRNA sequencing methods and confirmed that the LAB was Lactobacillus fermentum. Gram staining showed that the isolated bacteria were Gram-positive bacilli and the catalase assay and fermentation type showed it to be negative catalase and homofermentative.

Gökkuşağı Alabalığı Bağırsaklarından İzole Edilen Laktik Asit Bakterilerinin Lactococcus garvieae’ye Karşı Probiyotik Potansiyelinin İn Vitro Olarak Belirlenmesi

Bu çalışma amacı, gökkuşağı alabalıklarının bağırsak mikroflorasından Lactococcus garvieae’ye karşı antagonostik etkiye sahip Laktik Asit Bakterilerinin (LAB) izole edilmesi ve antagonostik etkiye sahip olduğu belirlenen bakteriyel türlerin olası probiyotik potansiyelinin in vitro olarak ortaya konulmasıdır. Bu amaçla Gökkuşağı alabalıklarının bağırsak florasından LAB türleri konvansiyonel kültür metotları kullanılarak izole edildi. Elde edilen izolatların L. garvieae’ye karşı antagonostik etkinlikleri agar well difüzyon testi ile belirlendi. Sonraki aşamada antagonostik aktiviteye sahip olduğu belirlenen izolatların hidrofobisitesi, pH ve safra tolerans düzeyleri ve antibiyotik duyarlılık profilleri belirlendi. Elde edilen aday probiyotik bakterilerinin genetik identifikasyonu PCR metodu ile gerçekleştirildi. Balıkların bağırsak florasından toplamda 47 izolat elde edildi. Bu izolatların 6’sının L. garvieae’ye karşı antagonostik etkinliğe sahip olduğu belirlendi. İleri testlerde izolatların hidrofobik özellikte oldukları, yüksek safra ve düşük pH şartlarına dirençli oldukları ve izolatların tamamının beş farklı antibiyotiğe karşı dirençli olduğu belirlendi. Genetik identifikasyon sonucu izolatlardan beşi Lactobacillus acidophilus olarak identifiye edildi. Bir izolat ise Lactobacillus spp. olarak tanımlandı. Bu çalışma ile ülkemiz kültür balığı yetiştiriciliğinde yaygın olarak görülen L. garvieae’nın kontrol altına alınmasında kullanılabilecek olası probiyotik bakteriler elde edilmiştir.

Potential of Lactic Acid Bacteria Isolated From Different Forages as Silage Inoculants for Improving Fermentation Quality and Aerobic Stability.

We aimed at isolating lactic acid bacteria (LAB) from different plant materials to study their crossed-fermentation capacity in silos and to find strains able to confer enhanced aerobic stability to silage. A total of 129 LAB isolates were obtained from lucerne (alfalfa), maize, sorghum, ryegrass, rice, barley, canola, Gatton panic, Melilotus albus, soy, white clover, wheat, sunflower, oat, and moha. Four Lactiplantibacillus plantarum subsp. plantarum strains (isolated from oat, lucerne, sorghum, or maize) were selected for their growth capacity. Identity (16S sequencing) and diversity (RAPD-PCR) were confirmed. Fermentative capacity (inoculated at 104, 105, 106, 107 CFU/g) was studied in maize silage and their cross-fermentation capacity was assessed in oat, lucerne, sorghum, and maize. Heterofermentative strains with the highest acetic acid production capacity conferred higher aerobic stability to maize silages. Regardless the source of isolation, L. plantarum strains, inoculated at a rate of 106 CFU/g, were effective to produce silage from different plant materials. From more than 100 isolates obtained, the application of a succession of experiments allowed us to narrow down the number of potential candidates of silage inoculants to two strains. Based on the studies made, L. plantarum LpM15 and Limosilactobacillus fermentum LfM1 showed potential to be used as inoculants, however further studies are needed to determine their performance when inoculated together. The former because it positively influenced different quality parameters in oat, lucerne, sorghum, and maize silage, and the latter because of its capacity to confer enhanced aerobic stability to maize silage. The rest of the strains constitute a valuable collection of autochthonous strains that will be further studied in the future for new applications in animal or human foods.

Screening of probiotic Lactobacilli with potential anti-allergic activity based on hyaluronidase inhibition and degranulation of RBL-2H3 cells in vitro

In the present study, the probiotic potential of lactic acid bacteria (LAB) isolated from different dairy sources were evaluated, and probiotics with anti-allergic activity were further screened based on the hyaluronidase inhibition assay and the degranulation of RBL-2H3 cells in vitro. As a result, Out of 20 strains, 15 LAB exhibited desirable probiotic properties and safety in vitro. Considering the suppressive activities on hyaluronidase and β-hexosaminidase release in degranulation-induced RBL-2H3 cells, strains LZ077E, LZ183E, and LZ260E exhibited potential probiotic properties that could be useful for alleviating allergic diseases. To evaluate the reliability of this result, the efficacy of these three strains on the expression of some cytokines and proteins in the signal pathway related to the FcεRI receptor on the RBL-2H3 cell surface were analyzed. The results show three strains exhibited remarkable downregulation of histamine and cytokines TNF-α and IL-4. Similarly, immunoblot analysis revealed that the probiotics also significantly decreased the phosphorylation of Lyn and Syk in RBL-2H3 cells. Our preliminary results may provide some scientific support for the use of probiotics for the treatment of allergic and inflammatory diseases, as well as the rapid screening of anti-allergic active probiotics in vitro.

Probiotic potential of lactic acid bacteria isolated from traditionally fermented legume products of Western Kenya

Fermentation as a processing technique has been used for a long time by people of Western Kenya to improve the quality of raw food material. During fermentation, lactic acid bacteria (LAB) synthesize vitamins and minerals, produce biologically active peptides with enzymes such as proteinase and peptidase, and remove some ant-nutrients. The medicinal and i¬‚avor enhancing properties of fermented foods are due to the presence of probiotics. This study aims at isolating and biochemically characterizing potential probiotic lactic acid bacteria from spontaneously fermented legume-based products from two locations in Vihiga County; Emuhaya and Mbale, Kenya. The results from the findings are presumptive indicator of probiotic bacteria in fermented legumes. RC0PU2, SB0PU3 and CP0PU1 isolated form Emuhaya can survive at low pH of 2 while SB0PU3 and CP0PU1 in addition can survive a salt concentration of 3%. SB0PU3 and CPOPU2 and RC0PU2, SB0PU2 and CPOPU3 can grow at high temperature of 45°C. RC0PU2, SB0PU2, GG0PU1, CP0PU1 and CPOPU2 can tolerate a salt concentration of 3%. Only two isolates RCOPU2 and CPOPU2 isolated from Mbale samples survived at the pH of 2. The findings from this study indicated that fermented legumes are potential sources of probiotics with unique characteristics. Key words: Probiotic potential, legumes, lactic acid bacteria.

Selection of potential lactic acid bacteria from fermented Sumbawa mare’s milk as starter cultures

Selection of potential lactic acid bacteria from fermented Sumbawa mare’s milk as starter cultures

Identification and probiotic potential of lactic acid bacteria from camel milk.

In the present study, a total of 80 presumed lactic acid bacteria (LAB) were isolated from camel milk. Selected LAB were identified as Lactococcus lactis (cam 12), Enterococcus lactis (cam 14) and Lactobacillus plantarum (cam 15) and their potential were tested by tolerance & de-conjugation of bile salts, antimicrobial activity, surface hydrophobicity and adhesion potential) along with this of probiotics were evaluated for curd formation and assessed for sensory properties and syneresis. Selected LABs showed antimicrobial activity against wide range of pathogenic bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus cereus and Escherchiaia. coli). LAB (cam 12, cam 14 and cam15) were highly sceptible to chloramphenicol, vancomycin, and tetracyclin. In vitro adhesion studies with Caco-2 cells demonstrated strong adhesion activity with hydrophobicity (99%) was observed. Acute oral toxicity of E. lactis and L. plantarum showed non-toxic, non-virulent and safe for industrial application. The study provides potential LAB which may act as a substitute of functional food, synthetic feed and industrial curd formulation with in the shortest span (240min at 28-32°C).