WorldWideScience

Sample records for acid bacteria inhibiting

  1. Inhibition of aflatoxin-producing aspergilli by lactic acid bacteria ...

    African Journals Online (AJOL)

    A total of six lactic acid bacteria (LAB) isolates were selected from five indigenously fermented cereal gruels and identified as Lactobacillus fermentum OYB, Lb. fermentum RS2, Lb. plantarum MW, Lb. plantarum YO, Lb. brevis WS3, and Lactococcus spp. RS3. Six aflatoxin-producing aspergilli were also selected from the ...

  2. Antibiotics influence on lactic acid bacteria inhibiting gastrointestinal tract

    Directory of Open Access Journals (Sweden)

    Andreja Čanžek Majhenič

    2001-04-01

    Full Text Available Lactic acid bacteria (LAB are common inhabitants of the gastrointestinal (GI tract and have important role in maintaining the equilibrium of GI flora, which can be influenced by various factors like diets, antimicrobials and stress. Minimal inhibitory concentrations (MIC and minimal bactericidal concentrations (MBC of 6 antibiotics, commonly used in human medicine for 8 selected lactobacilli strains were determined by macrodilution and microdilution methods in liquid media and by diffusion method on agar plates. The effects of Penicillin G and Ampicillin on intestinal LAB were tested in vivoon mice as well. Lactobacilli were sensitive to Penicillin G, (penicillines and their derivatives and Erythromycin (macrolides by in vitro testing. Clyndamycin (pyranosid showed moderate inhibitory effect. All lactobacilli strains were resistant to Kanamycin and Neomycin (aminoglycosides, while L. salivarius IM 124 has shown extra resistance to Erythromycin and Clyndamycin. The influence of orally administered Ampicillin showed no significant influence on LAB count in mice faeces. The effect of Penicillin G on mice LAB total count was significant, while no effect of orally administered lactobacilli was determined.

  3. Inhibition of hydrogen fermentation of organic wastes by lactic acid bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Noike, Tatsuya; Takabatake, Hiroo [Tohoku Univ., Sendai (Japan). Dept. of Civil Engineering; Japan Science and Technology Corporation, Saitama (Japan). CREST; Mizuno, Osama [Ataka Construction and Engineering Co., Osaka (Japan); Ohba, Mika [Japan Science and Technology Corporation, Saitama (Japan). CREST

    2002-12-01

    The effects of lactic acid bacteria (LAB) on hydrogen fermentation of organic waste were investigated. For this three hydrogen producing strains of Clostridium were cultured with two lactic acid bacteria, i.e. Lactobacillus paracasei and Enterococcus durans, which were isolated from the wastes generated in the bean curd manufacturing. The decrease or cessation of hydrogen production by Clostridium was caused by the addition of LAB. The supernatants of L. paracasei and E. durans suspensions also inhibited hydrogen production by Clostridium. This inhibition was partially destroyed in the presence of trypsin, which is a protease inactivating a bacteriocin. These results suggest that the inhibitory effect of lactic acid bacteria on hydrogen production was caused by bacteriocins excreted from LAB which have a deleterious effect on other bacteria. To suppress any effect by LAB, heat treatment of this waste was investigated as a possible pretreatment step. The inhibition of hydrogen production was reduced by heat treatment for 30 min at temperatures ranging from 50{sup o}C to 90{sup o}C. This means that a temperature of 50{sup o}C is already adequate to prevent growth of LAB. (Author)

  4. Sugar fatty acid esters inhibit biofilm formation by food-borne pathogenic bacteria

    Science.gov (United States)

    Furukawa, Soichi; Akiyoshi, Yuko; O’Toole, George A.; Ogihara, Hirokazu; Morinaga, Yasushi

    2010-01-01

    Effects of food additives on biofilm formation by food-borne pathogenic bacteria were investigated. Thirty-three potential food additives and 3 related compounds were added to the culture medium at concentrations from 0.001 to 0.1% (w/w), followed by inoculation and cultivation of five biofilm-forming bacterial strains for the evaluation of biofilm formation. Among the tested food additives, 21 showed inhibitory effects of biofilm formation by Staphylococcus aureus and Escherichia coli, and in particular, sugar fatty acid esters showed significant anti-biofilm activity. Sugar fatty acid esters with long chain fatty acid residues (C14-16) exerted their inhibitory effect at the concentration of 0.001%(w/w), but bacterial growth was not affected at this low concentration. Activities of the sugar fatty acid esters positively correlated with the increase of the chain length of the fatty acid residues. Sugar fatty acid esters inhibited the initial attachment of the Staphylococcus aureus cells to the abiotic surface. Sugar fatty acid esters with long chain fatty acid residues (C14-16) also inhibited biofilm formation by Streptococcus mutans and Listeria monocytogenes at 0.01%(w/w), while the inhibition of biofilm formation by Pseudomonas aeruginosa required the addition of a far higher concentration (0.1%(w/w)) of the sugar fatty acid esters. PMID:20089325

  5. Inhibition Effect of Lactic Acid Bacteria against Food Born Pathogen, Listeria monocytogenes

    Directory of Open Access Journals (Sweden)

    Rouha Kasra-Kermanshahi

    2015-09-01

    Full Text Available Disease caused by consuming microbial contaminated food has increased significantly in recent years due to changes in the livelihoods and eating habits of the human populations. Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella enterica are three of the most important foodborne bacterial pathogens and can lead to foodborne diseases. Increased use of antibiotics, has led to development of bacterial resistance to antibiotics. Therefore, there is growing interest in the development of new types of effective and nontoxic antimicrobial compounds. Nowadays, the most extensive research and commercial practices are based on probiotic bacteria. Probiotics, specifically lactic acid bacteria are widely used in the food industry for fermentation but have gained attention from health professionals because of their potential beneficial effects. Now probiotic therapy is thought to be an effective way to improve the gut health and an alternative to antibiotic treatments. They contribute to food safety by their ability to inhibit the growth of several other bacteria. LAB can be used as protective cultures to compete with potential pathogens and other undesired organisms, thereby increasing the safety of the food product.

  6. In-situ inhibition of Staphylococcus aureus by lactic acid bacteria consortia from two traditional Slovenian raw milk cheeses

    Directory of Open Access Journals (Sweden)

    Aljoša Trmčić

    2010-09-01

    Full Text Available Bacteriocin(s producing lactic acid bacteria naturally present in traditional cheeses represent an inexhaustive pool of microbes with safeguarding potential. Some bacteriocins produced by cheese lactic acid bacteria were already described as successful anti-staphylococcal agents. The presence of genes for bacteriocins with potential anti-staphylococcal activity was also demonstrated in two Slovenian traditional raw milk cheeses, “Tolminc” and “Kraški ovčji sir”. Same bacteriocin genes were also detected in viable lactic acid bacteria consortia’s isolated from “bacteriocin positive cheeses” on Rogosa, M17 and CATC agar media. The aim of the research was to elucidate whether or not this particular cheese consortia, in which bacteriocin genes were detected, actually exhibit anti-staphylococcal activity in milk and/or cheese. For this purpose different cheese consortia were selected in relation to versatility of detected bacteriocin genes and used to perform challenge tests against Staphylococcus aureus in milk and cheese. In milk following the time/temperature regime of traditional cheese production all cheese consortia effectively inhibited growth of Staphylococcus aureus in the range of app. 2 to 3 log. In cheese the inhibition of staphylococci was less pronounced but still evident since inhibition of app. 1.5 log was detected. Sole inhibition by lactic acid production was ruled out whilelinking inhibition directly to bacteriocin production would take some additional work.

  7. Process for inhibiting the growth of a culture of lactic acid bacteria, and optionally lysing the bacterial cells, and uses of the resulting lysed culture

    NARCIS (Netherlands)

    Nauta, Arjen; Venema, Gerard; Kok, Jan; Ledeboer, Aat M.

    1995-01-01

    The invention provides a process for inhibiting the growth of a culture of lactic acid bacteria, or a product containing such culture e.g. a cheese product, in which in the cells of the lactic acid bacteria a holin obtainable from bacteriophages of Gram-positive bacteria, esp. from bacteriophages of

  8. Short communication: Lactic acid bacteria from the honeybee inhibit the in vitro growth of mastitis pathogens.

    Science.gov (United States)

    Piccart, K; Vásquez, A; Piepers, S; De Vliegher, S; Olofsson, T C

    2016-04-01

    Despite the increasing knowledge of prevention and control strategies, bovine mastitis remains one of the most challenging diseases in the dairy industry. This study investigated the antimicrobial activity of 13 species of lactic acid bacteria (LAB), previously isolated from the honey crop of the honeybee, on several mastitis pathogens. The viable LAB were first reintroduced into a sterilized heather honey matrix. More than 20 different bovine mastitis isolates were tested against the mixture of the 13 LAB species in the honey medium using a dual-culture overlay assay. The mastitis isolates were identified through bacteriological culturing, followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Additionally, the mastitis isolates were subjected to antimicrobial susceptibility testing through disk diffusion. Growth of all tested mastitis pathogens, including the ones displaying antimicrobial resistance to one or more antimicrobial compounds, were inhibited to some extent by the honey and LAB combination. The antibacterial effect of these LAB opens up new perspectives on alternative treatment and prevention of bovine mastitis. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  9. In vitro growth inhibition of intra root canal pathogenic microorganisms by Lactic Acid Bacteria, an Antibiosis method

    Directory of Open Access Journals (Sweden)

    A. Nakhjavani F.

    2008-12-01

    Full Text Available "nBackground and Aim: Elimination of microorganisms and their byproducts from root canal system is one of important aims of root canal therapy. This object is gained by using of many chemomechanical techniques but with noncertain success. A new method is used of nonpathogenic bacteria for growth inhibition of pathogenic bacteria, Antibiosis, in root canal therapy.The aim of this study was in vitro evaluation of antimicrobial effect of probiotics, such as Lactic Acid Bacteria (LAB on the infected root canal bacteria. "nMaterials and Methods: Isolated bacteria from infected root canal were grown and then scattered onto the muller Hinton agar plates which contain wells, LAB, extracted from dairy products, were added into these wells, Inhibition effected of LAB was determined. Furthermore the sample taken from the inhibition zone and possible resistant monoclonal bacteria also were identified, then 6 sensitive and 14 resistant samples were selected and E. faecalis species were added to them; Then antimicrobial effects of LAB on these samples was reevaluated. "nResults: The results showed that 66.7% of the samples were sensitive at least to one type of LAB, and 33% were resistant to all kind of LAB. Meanwhile the outgrowing anaerobic bacteria inside the inhibition zone were from the low frequency oral bacterial flora. Furthermore, adding E. faecalis to the samples caused more sensitivity of them to LAB. Mc-Neamar test recognized the difference significant. "nConclusion: This study showed that the LAB inhibit growth of the pathogenic root canal bacteriae. Furthermore, presence of E. faecalis reinforces the antimicrobial effect of LAB. It seemed that LAB maybe have potential to use in endodontic practice for elimination of root canal infections.

  10. Effect of inhibition on tyrosinase and melanogenesis of Agastache rugosa Kuntze by lactic acid bacteria fermentation.

    Science.gov (United States)

    Kim, Nam Young; Kwon, Hee Souk; Lee, Hyeon Yong

    2017-09-01

    This work presents the first report that A. rugosa could have tyrosinase and melanogenesis inhibition and that its activities also be improved by fermentation with Lactobacillus rhamnosus and Lactobacillus paracasei. It was found that the tyrosinase and melanogenesis inhibition was correlated with antioxidant activity of acacetin, the major biologically active substances in A. rugosa. we pursued an improvement in tyrosinase and melanogenesis inhibition of A. rugosa extract by fermentation process. A. rugosa was extracted by lactic acid fermentation process; we measured antioxidant activities and tyrosinase and melanogenesis inhibition of A. rugosa extracts. In particular, reducing power of the extract from fermentation process (FE) was measured as 0.562 (O.D.), whereas reducing power of the extracts from 70% ethanol extraction (EE) was lower than the FE as 0.496 (O.D.). Polyphenols and flavonoids in the FE were higher than the EE: 69.3 mg/g vs. 60.5 mg/g, and 187 mg/g vs. 138 mg/g. The FE was estimated as 51.04% tyrosinase inhibition and 41.88% for the EE. Similarly, melanin inhibition in melanocyte B16F10 was observed as 66.60% vs. 42.23% for the FE and EE. The increase in tyrosinase and melanogenesis inhibition activity was confirmed by high elution of acacetin through fermentation process such as 289.97 mg/100 g vs. 198.04 mg/100 g in the FE and EE. These results indicate that tyrosinase and melanogenesis inhibition activities of the extracts should be associated with antioxidant activity because acacetin is known to have strong antioxidant activity, which can also positively affect whitening activities. © 2016 Wiley Periodicals, Inc.

  11. Beneficial bacteria inhibit cachexia

    Science.gov (United States)

    Varian, Bernard J.; Goureshetti, Sravya; Poutahidis, Theofilos; Lakritz, Jessica R.; Levkovich, Tatiana; Kwok, Caitlin; Teliousis, Konstantinos; Ibrahim, Yassin M.; Mirabal, Sheyla; Erdman, Susan E.

    2016-01-01

    Muscle wasting, known as cachexia, is a debilitating condition associated with chronic inflammation such as during cancer. Beneficial microbes have been shown to optimize systemic inflammatory tone during good health; however, interactions between microbes and host immunity in the context of cachexia are incompletely understood. Here we use mouse models to test roles for bacteria in muscle wasting syndromes. We find that feeding of a human commensal microbe, Lactobacillus reuteri, to mice is sufficient to lower systemic indices of inflammation and inhibit cachexia. Further, the microbial muscle-building phenomenon extends to normal aging as wild type animals exhibited increased growth hormone levels and up-regulation of transcription factor Forkhead Box N1 [FoxN1] associated with thymus gland retention and longevity. Interestingly, mice with a defective FoxN1 gene (athymic nude) fail to inhibit sarcopenia after L. reuteri therapy, indicating a FoxN1-mediated mechanism. In conclusion, symbiotic bacteria may serve to stimulate FoxN1 and thymic functions that regulate inflammation, offering possible alternatives for cachexia prevention and novel insights into roles for microbiota in mammalian ontogeny and phylogeny. PMID:26933816

  12. Identification of organic acids in Cichorium intybus inhibiting virulence-related properties of oral pathogenic bacteria.

    Science.gov (United States)

    Papetti, Adele; Mascherpa, Dora; Carazzone, Chiara; Stauder, Monica; Spratt, David A; Wilson, Michael; Pratten, Jonathan; Ciric, Lena; Lingström, Peter; Zaura, Egija; Weiss, Ervin; Ofek, Itzak; Signoretto, Caterina; Pruzzo, Carla; Gazzani, Gabriella

    2013-06-01

    The low molecular mass (LMM) extract of Cichorium intybus var. silvestre (red chicory) has been shown to inhibit virulence-linked properties of oral pathogens including Streptococcus mutans, Actinomyces naeslundii and Prevotella intermedia. In the present study HPLC-DAD-ESI/MS(2) was used to investigate the compounds contained in this extract for their anti-virulence activity. The extract contained a number of components, including oxalic, succinic, shikimic and quinic acids, which interfere with the growth and virulence traits (i.e., biofilm formation, adherence to epithelial cells and hydroxyapatite) of oral pathogens involved in gingivitis and tooth decay. Succinic and quinic acid seem to be the most potent, mainly by interfering with the ability of oral pathogens to form biofilms (either through inhibition of their development or promotion of their disruption). Our findings suggest that one or more of these compounds may modulate plaque formation in vivo, which is a prerequisite for the development of both caries and gingivitis. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. INHIBITION OF STAPHYLOCOCCUS AUREUS BY LACTIC ACID BACTERIA AND / OR BIFIDOBACTERIUM LACTIS DURING MILK FERMENTATION AND STORAGE

    Directory of Open Access Journals (Sweden)

    Khalaf S. Al-Delaimy

    2013-02-01

    Full Text Available Survival and inhibition of Staphylococcus aureus by the lactic acid bacteria (LAB starter culture (Sterptococcus thermophillus and Lactobacillus delbrukii subsp. bulgaricus and/ or probiotic bacteria Bifidobacterium lactis during milk fermentation to yoghurt and storage up to 12 days was studied. Adding S. aureus (initial count log 6.64/ ml with LAB (initial count log 6.8/ ml in milk during yoghurt processing and storage resulted in no significant change in the counts of both S. aureus and LAB during fermentation period of 4 hrs at 45° C. A steady decrease in S. aureus count during storage at 25° C and 4° C was observed reaching a complete (100 % inhibition after 9 and 12 days, respectively, with no significant increase in LAB count. Adding S. aureus (initial count log 6.62/ ml with B. lactis (initial count log 6.83/ ml in milk for 4 hr at45° C, no significant changes in the counts of both bacteria were found. After storage at 25° C and at 4° C a sharp decline in the S. aureus count with a 100 % inhibition after 6 and 9 days with approximately two log and one log increase in B. lactis counts consecutively. In general similar result was observed when adding S. aureus together with LAB and B. lactis in milk during fermentation and storage. pH values decreased during milk fermentation and storage from initially 6.55-6.64 to around 4 in most milk samples. The results of this study show that S. aureus was completely inhibited by LAB and/or B. lactis after milk fermentation to yoghurt and storage at room temperature and refrigeration for 6-9 days. It is therefore recommended to add the probiotic B. lactis with LAB to milk for yoghurt processing.

  14. Inhibition of fructan-fermenting equine faecal bacteria and Streptococcus bovis by hops (Humulus lupulus L.) β-acid.

    Science.gov (United States)

    Harlow, B E; Lawrence, L M; Kagan, I A; Flythe, M D

    2014-08-01

    The goals of this study were to determine if β-acid from hops (Humulus lupulus L.) could be used to control fructan fermentation by equine hindgut micro-organisms, and to verify the antimicrobial mode of action on Streptococcus bovis, which has been implicated in fructan fermentation, hindgut acidosis and pasture-associated laminitis (PAL) in the horse. Suspensions of uncultivated equine faecal micro-organisms produced fermentation acids when inulin (model fructan) was the substrate, but β-acid (i.e. lupulone) concentrations ≥9 ppm inhibited lactate production and mitigated the decrease in pH. Inulin-fermenting Strep. bovis was isolated from the β-acid-free suspensions after enrichment with inulin. The isolates were sensitive to β-acid, which decreased the viable number of streptococci in faecal suspensions, as well as growth, lactate production and the intracellular potassium of Strep. bovis in pure culture. These results are consistent with the hypothesis that hops β-acid prevented the growth of fructan-fermenting equine faecal bacteria, and that the mechanism of action was dissipation of the intracellular potassium of Strep. bovis. Bacterial hindgut fermentation of grass fructans has been linked to PAL and other metabolic disorders in horses. Hops β-acid is a potential phytochemical intervention to decrease the growth of bacteria responsible for PAL. © 2014 The Society for Applied Microbiology. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

  15. Surface functionalization of titanium substrates with chitosan-lauric acid conjugate to enhance osteoblasts functions and inhibit bacteria adhesion.

    Science.gov (United States)

    Zhao, Lu; Hu, Yan; Xu, Dawei; Cai, Kaiyong

    2014-07-01

    Orthopedic implants failures are generally related to poor osseointegration and/or bacterial infection in clinical application. Surface functionalization of an implant is one promising alternative for enhancing osseointegration and/or reducing bacterial infection, thus ensuring the long term survival of the implant. In this study, titanium (Ti) substrates were surface functionalized with a polydopamine (PDOP) film as an intermediate layer for post-immobilization of chitosan-lauric acid (Chi-LA) conjugate. Chi-LA conjugate was synthesized and characterized by Fourier transform infrared spectroscopy (FTIR) and hydrogen proton nuclear magnetic resonance (NMR) spectrometer, respectively. Lauric acid (LA), a natural saturated fatty acid, was used mainly due to its good antibacterial property. Scanning electron microscopy (SEM) and water contact angle measurements were employed to detect the morphology changes and surface wettability of Ti substrates. The results suggested that Chi-LA conjugate was successfully immobilized onto the surfaces of Ti substrates. In vitro tests confirmed that the cell adhesion, cell viability, intracellular alkaline phosphatase activity and mineralization capacity of osteoblasts were remarkably improved when cultured onto Chi-LA surface functionalized Ti substrates. Antibacterial assay against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) showed that the Chi-LA modified Ti substrates efficiently inhibited the adhesion and growth of bacteria. Overall, this study developed a promising approach to fabricate functional Ti-based orthopedic implants, which could enhance the biological functions of osteoblasts and concurrently reduce bacteria adhesion. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Selection of probiotic lactic acid bacteria able to inhibit β-hemolytic Escherichia coli isolated from diarrheal piglets

    Directory of Open Access Journals (Sweden)

    Malawach, T.

    2007-05-01

    Full Text Available A total of 306 isolates of lactic acid bacteria were isolated from 250 samples of piglet faeces. The strains were investigated for preliminary probiotic properties based on their stability in bile salts (0.30%and high acidity (pH 3.0. Ability to utilize protein, fat and starch, growth in the absence of vitamin B12 and growth with both aerobic and anaerobic conditions were also considered. As a result of above criteria, 20isolates were selected. Using an agar spot method, all isolates were able to inhibit β-hemolytic Escherichia coli 240/2 under aerobic and anaerobic condition. A further investigation using a co-culture techniqueshowed that only six isolates inhibited β-hemolytic E. coli 240/2, E. coli K88 and E. coli K 99 by more than 90 percent. The selected isolates were resistant to the following antibiotics: amikacin, polymyxin B andnalidixic acid; however the strains were susceptible to erythromycin and chloramphenicol. All six active isolates were identified as Lactobacillus plantarum by API 50 CH system.

  17. Identification of organic acids in Cichorium intybus inhibiting virulence-related properties of oral pathogenic bacteria

    NARCIS (Netherlands)

    Papetti, A.; Mascherpa, D.; Carazzone, C.; Stauder, M.; Spratt, D.A.; Wilson, M.; Pratten, J.; Ciric, L.; Lingström, P.; Zaura, E.; Weiss, E.; Ofek, I.; Signoretto, C.; Pruzzo, C.; Gazzani, G.

    2013-01-01

    The low molecular mass (LMM) extract of Cichorium intybus var. silvestre (red chicory) has been shown to inhibit virulence-linked properties of oral pathogens including Streptococcus mutans, Actinomyces naeslundii and Prevotella intermedia. In the present study HPLC-DAD-ESI/MS2 was used to

  18. Use of Bacteriocinogenic Cultures without Inhibiting Cheese Associated Nonstarter Lactic Acid Bacteria; A Trial with Lactobacillus plantarum

    Directory of Open Access Journals (Sweden)

    Franca Rossi

    2016-02-01

    Full Text Available Bacteriocinogenic cultures can represent a natural way to increase the safety of cheeses made from raw milk, in which a relevant role in ripening and flavor formation is exerted by the nonstarter lactic acid bacteria (NSLAB. Since the latter can be inhibited by bacteriocin producers, this study evaluated to which extent a nisinogenic culture inoculated at low initial levels can affect the growth rate and peptide degradation activity of the nisin-sensitive cheese isolate Lactobacillus plantarum LZ by comparison with its isogenic variant, L. plantarum LZNI, with increased immunity to nisin. A growth delay of the nisin sensitive strain was observed only when its initial number was 100-fold lower than the nisin producer and nisin was added as an inducer of its own production. In this case, the amount of free α-amino groups was significantly different between cultures of L. plantarum LZ and LZNI only at Day 1. Reverse Phase High Performance Liquid Chromatography (RP-HPLC highlighted a few differences between the peptide profiles of co-cultures L. plantarum LZ and LZNI. However, results showed that the bacteriocin producer did not dramatically influence the behavior of the sensitive NSLAB and that the evaluation of the effects on microbial contaminants in cheese is worthwhile.

  19. Fungal inhibitory lactic acid bacteria

    OpenAIRE

    Ström, Katrin

    2005-01-01

    Lactic acid bacteria (LAB) are microorganisms that have been used for centuries to prepare and improve storage of food and for ensiling of different crops for animal feed. This thesis explores the possibility of using LAB to inhibit growth of spoilage fungi in food and feed products. LAB isolates, collected from plant material or dairy products, were screened for antifungal activity in a dual culture assay. Strains with antifungal activity were identified and the fungal inhibitory activity wa...

  20. Bacterial contaminants from frozen puff pastry production process and their growth inhibition by antimicrobial substances from lactic acid bacteria.

    Science.gov (United States)

    Rumjuankiat, Kittaporn; Keawsompong, Suttipun; Nitisinprasert, Sunee

    2017-05-01

    Seventy-five bacterial contaminants which still persisted to cleaning system from three puff pastry production lines (dough forming, layer and filling forming, and shock freezing) were identified using 16S rDNA as seven genera of Bacillus , Corynebacterium , Dermacoccus , Enterobacter , Klebsiella, Pseudomonas , and Staphylococcus with detection frequencies of 24.00, 2.66, 1.33, 37.33, 1.33, 2.66, and 30.66, respectively. Seventeen species were discovered while only 11 species Bacillus cereus, B. subtilis, B. pumilus, Corynebacterium striatum , Dermacoccus barathri , Enterobacter asburiae, Staphylococcus kloosii, S. haemolyticus, S. hominis, S. warneri , and S. aureus were detected at the end of production. Based on their abundance, the highest abundance of E. asburiae could be used as a biomarker for product quality. While a low abundance of the mesophile pathogen C. striatum , which causes respiratory and nervous infection and appeared only at the shock freezing step was firstly reported for its detection in bakery product. Six antimicrobial substances (AMSs) from lactic acid bacteria, FF1-4, FF1-7, PFUR-242, PFUR-255, PP-174, and nisin A were tested for their inhibition activities against the contaminants. The three most effective were FF1-7, PP-174, and nisin A exhibiting wide inhibition spectra of 88.00%, 85.33%, and 86.66%, respectively. The potential of a disinfectant solution containing 800 AU/ml of PP-174 and nisin A against the most resistant strains of Enterobacter , Staphylococcus , Bacillus and Klebsiella was determined on artificially contaminated conveyor belt coupons at 0, 4, 8, 12, and 16 hr. The survival levels of the test strains were below 1 log CFU/coupon at 0 hr. The results suggested that a combined solution of PP-174 and nisin A may be beneficial as a sanitizer to inhibit bacterial contaminants in the frozen puff pastry industry.

  1. Lactic Acid Bacteria Inducing a Weak Interleukin-12 and Tumor Necrosis Alpha Response in Human Dendritic Cells Inhibit Strongly Stimulating Lactic Acid Bacteria but Act Synergistically with Gram-Negative Bacteria

    DEFF Research Database (Denmark)

    Zeuthen, Louise Hjerrild; Christensen, Hanne Risager; Frøkiær, Hanne

    2006-01-01

    The development and maintenance of immune homeostasis indispensably depend on signals from the gut flora. Lactic acid bacteria (LAB), which are gram-positive (G+) organisms, are plausible significant players and have received much attention. Gram-negative (G-) commensals, such as members...

  2. The role of lactic acid bacteria (Lactobacillus sp yel133) from beef in inhibiting of microbial contaminants on various fillers of starter culture

    Science.gov (United States)

    Yunilas; Mirwandhono, E.

    2018-02-01

    The role of Lactic Acid Bacteria (LAB) on the starter culture can be seen from the ability to grow and suppress the growth of microbial contaminants (fungi). The research aimed to investigate the role of LAB (Lactobacillus sp YEL133) in inhibiting microbial contaminants (fungi) on starter cultures of various fillers. The materials used in this research was Lactobacillus sp YEL133 from beef and various fillers (rice flour, corn starch and wheat flour). The research methods used completely randomized design (CRD) with 3 treatments and 4 replications. The treatments of this research was P1(rice flour), P2 (corn starch) and P3 (wheat flour) that inoculated with Lactobacillus sp YEL133. Parameters which is observed such as: growth of lactic acid bacteria, total microbes and total fungi as microbial contaminants. The results showed that the starter culture with a filler material of rice flour produce lactic acid bacteria and microbes were highly significant (P <0.01) for corn starch and wheat flour, as well as able to suppress the growth of microbial contaminants (fungi). The conclusion of the research is the use Lactobacillus sp YEL133 can suppress the growth of fungi on the starter culture using rice flour.

  3. LACTIC ACID BACTERIA: PROBIOTIC APPLICATIONS

    OpenAIRE

    NEENA GARG

    2015-01-01

    Lactic acid bacteria (LAB) is a heterotrophic Gram-positive bacteria which under goes lactic acid fermentations and leads to production of lactic acid as an end product. LAB includes Lactobacillus, Leuconostoc, Pediococcus, Lactococcus and Streptococcus which are grouped together in the family lactobacillaceae. LAB shows numerous antimicrobial activities due to production of antibacterial and antifungal compounds such as organic acids, bacteriocins, diacetyl, hydrogen peroxide and reutrin. LA...

  4. [Teichoic acids from lactic acid bacteria].

    Science.gov (United States)

    Livins'ka, O P; Harmasheva, I L; Kovalenko, N K

    2012-01-01

    The current view of the structural diversity of teichoic acids and their involvement in the biological activity of lactobacilli has been reviewed. The mechanisms of effects of probiotic lactic acid bacteria, in particular adhesive and immunostimulating functions have been described. The prospects of the use of structure data of teichoic acid in the assessment of intraspecific diversity of lactic acid bacteria have been also reflected.

  5. Eugenol stimulates lactate accumulation yet inhibits volatile fatty acid production and eliminates coliform bacteria in cattle and swine waste.

    Science.gov (United States)

    Varel, V H; Miller, D L

    2004-01-01

    To determine how eugenol affects fermentation parameters and faecal coliforms in cattle and swine waste slurries stored anaerobically. Waste slurries (faeces:urine:water, 50:35:15) were blended with and without additives and aliquoted to triplicate 1-l flasks. Faecal coliforms were eliminated in cattle and swine waste slurries within 1 or 2 days with additions of eugenol at 10.05 mm (0.15%) and 16.75 mm (0.25%). At these concentrations volatile fatty acids (VFA) were reduced ca 70 and 50% in cattle and swine waste, respectively, over 6-8 weeks. Additionally, in cattle waste, eugenol stimulated the accumulation of lactate (>180 mm) when compared with thymol treatment (20 mm lactate). In swine waste, lactate accumulation did not occur without additives; eugenol and thymol stimulated lactate accumulation to concentrations of 22 and 32 mm, respectively. Eugenol added to cattle waste may be more beneficial than thymol because not only does it effectively control faecal coliforms and odour (VFA production), it also stimulates lactate accumulation. This in turn, causes the pH to drop more rapidly, further inhibiting microbial activity and nutrient emissions. Plant essential oils have the potential to solve some of the environmental problems associated with consolidated animal feeding operations. Thymol and eugenol reduce fermentative activity, thus, have the potential to reduce emissions of greenhouse gases and odour, and curtail transmission of pathogens in cattle and swine wastes.

  6. Selection of autochthonous lactic acid bacteria from goat dairies and their addition to evaluate the inhibition of Salmonella typhi in artisanal cheese.

    Science.gov (United States)

    Ferrari, Iris da Silva; de Souza, Jane Viana; Ramos, Cintia Lacerda; da Costa, Mateus Matiuzzi; Schwan, Rosane Freitas; Dias, Francesca Silva

    2016-12-01

    This study aimed to select autochthonous lactic acid bacteria (LAB) with probiotic and functional properties from goat dairies and test their addition to artisanal cheese for the inhibition of Salmonella typhi. In vitro tests, including survival in the gastrointestinal tract (GIT), auto- and co-aggregation, the hemolytic test, DNase activity, antimicrobial susceptibility, antibacterial activity, tolerance to NaCl and exopolysaccharide (EPS), gas and diacetyl production were conducted for sixty isolates. Based on these tests, four LAB isolates (UNIVASF CAP 16, 45, 84 and 279) were selected and identified. Additional tests, such as production of lactic and citric acids by UNIVASF CAP isolates were performed in addition to assays of bile salt hydrolase (BSH), β-galactosidase and decarboxylase activity. The four selected LAB produced high lactic acid (>17 g/L) and low citric acid (0.2 g/L) concentrations. All selected strains showed BSH and β-galactosidase activity and none showed decarboxylase activity. Three goat cheeses (1, 2 and control) were produced and evaluated for the inhibitory action of selected LAB against Salmonella typhi. The cheese inoculated with LAB (cheese 2) decreased 0.38 log10 CFU/g of S. Typhy population while in the cheese without LAB inoculation (cheese 1) the pathogen population increased by 0.29 log units. Further, the pH value increased linearly over time, by 0.004 units per day in cheese 1. In the cheese 2, the pH value decreased linearly over time, by 0.066 units per day. The cocktail containing selected Lactobacillus strains with potential probiotic and technological properties showed antibacterial activity against S. typhi in vitro and in artisanal goat cheese. Thus, goat milk is important source of potential probiotic LAB which may be used to inhibit the growth of Salmonella population in cheese goat, contributing to safety and functional value of the product. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Lactic acid bacteria: inhibition of angiotensin converting enzyme in vitro and in vivo

    DEFF Research Database (Denmark)

    Fuglsang, Anders; Rattray, Fergal; Nilsson, Dan

    2003-01-01

    and ACE inhibition, indicating that peptide measurement constitutes a convenient selection method. The effect of active fermentates on in vivo ACE activity was demonstrated in normotensive rats. The pressor effect of angiotensin I (0.3 μg/kg) upon intravenous injection was significantly lower when rats...

  8. Lactic Acid Bacteria in Total Mixed Ration Silage Containing Soybean Curd Residue: Their Isolation, Identification and Ability to Inhibit Aerobic Deterioration

    Science.gov (United States)

    Li, Y.; Wang, F.; Nishino, N.

    2016-01-01

    We investigated the effects of the predominant lactic acid bacteria (LAB) on the fermentation characteristics and aerobic stability of total mixed ration (TMR) silage containing soybean curd residue (SC-TMR silage). The SC-TMR materials were ensiled in laboratory silos for 14 or 56 days. LAB predominant in SC-TMR silage were identified (Exp. 1). Lactobacillus fermentum (L. fermentum) and Streptococcus bovis (S. bovis) were found in the untreated materials, Leuconostoc pseudomesenteroides (L. pseudomesenteroides) in 14-day silage and Lactobacillus plantarum (L. plantarum) in all silages. Pediococcus acidilactici (P. acidilactici), Lactobacillus paracasei (L. paracasei), and Lactobacillus brevis (L. brevis) formed more than 90% of the isolates in 56-day silage. Italian ryegrass and whole crop maize were inoculated with P. acidilactici and L. brevis isolates and the fermentation and aerobic stability determined (Exp. 2). Inoculation with P. acidilactici and L. brevis alone or combined improved the fermentation products in ryegrass silage and markedly enhanced its aerobic stability. In maize silage, P. acidilactici and L. brevis inoculation caused no changes and suppressed deterioration when combined with increases in acetic acid content. The results indicate that P. acidilactici and L. brevis may produce a synergistic effect to inhibit SC-TMR silage deterioration. Further studies are needed to identify the inhibitory substances, which may be useful for developing potential antifungal agents. PMID:26949952

  9. Lactic Acid Bacteria in Total Mixed Ration Silage Containing Soybean Curd Residue: Their Isolation, Identification and Ability to Inhibit Aerobic Deterioration

    Directory of Open Access Journals (Sweden)

    Y. Li

    2016-04-01

    Full Text Available We investigated the effects of the predominant lactic acid bacteria (LAB on the fermentation characteristics and aerobic stability of total mixed ration (TMR silage containing soybean curd residue (SC-TMR silage. The SC-TMR materials were ensiled in laboratory silos for 14 or 56 days. LAB predominant in SC-TMR silage were identified (Exp. 1. Lactobacillus fermentum (L. fermentum and Streptococcus bovis (S. bovis were found in the untreated materials, Leuconostoc pseudomesenteroides (L. pseudomesenteroides in 14-day silage and Lactobacillus plantarum (L. plantarum in all silages. Pediococcus acidilactici (P. acidilactici, Lactobacillus paracasei (L. paracasei, and Lactobacillus brevis (L. brevis formed more than 90% of the isolates in 56-day silage. Italian ryegrass and whole crop maize were inoculated with P. acidilactici and L. brevis isolates and the fermentation and aerobic stability determined (Exp. 2. Inoculation with P. acidilactici and L. brevis alone or combined improved the fermentation products in ryegrass silage and markedly enhanced its aerobic stability. In maize silage, P. acidilactici and L. brevis inoculation caused no changes and suppressed deterioration when combined with increases in acetic acid content. The results indicate that P. acidilactici and L. brevis may produce a synergistic effect to inhibit SC-TMR silage deterioration. Further studies are needed to identify the inhibitory substances, which may be useful for developing potential antifungal agents.

  10. Inhibition of fructan-fermenting equine fecal bacteria and Streptococcus bovis by hops (Humulus lupulus L.) ß-acid

    Science.gov (United States)

    Aims: The goals were to determine if the '-acid from hops (Humulus lupulus L.) could be used to control fructan fermentation by equine hindgut microorganisms, and to verify the antimicrobial mode of action on the Streptococcus bovis, which has been implicated in fructan fermentation, hindgut acidos...

  11. Effectiveness of a Commercial Lactic Acid Bacteria Intervention Applied to Inhibit Shiga Toxin-Producing Escherichia coli on Refrigerated Vacuum-Aged Beef

    Directory of Open Access Journals (Sweden)

    Katie R. Kirsch

    2017-01-01

    Full Text Available Because of their antagonistic activity towards pathogenic and spoilage bacteria, some members of the lactic acid bacteria (LAB have been evaluated for use as food biopreservatives. The objectives of this study were to assess the antimicrobial utility of a commercial LAB intervention against O157 and non-O157 Shiga-toxigenic E. coli (STEC on intact beef strip loins during refrigerated vacuum aging and determine intervention efficacy as a function of mode of intervention application. Prerigor strip loins were inoculated with a cocktail (8.9±0.1 log10 CFU/ml of rifampicin-resistant (100.0 μg/ml; RifR O157 and non-O157 STEC. Inoculated loins were chilled to ≤4°C and treated with 8.7±0.1 log10 CFU/ml LAB intervention using either a pressurized tank air sprayer (conventional application or air-assisted electrostatic sprayer (ESS. Surviving STEC were enumerated on tryptic soy agar supplemented with 100.0 μg/ml rifampicin (TSAR to determine STEC inhibition as a function of intervention application method (conventional, ESS and refrigerated aging period (14, 28 days. Intervention application reduced STEC by 0.4 log10 CFU/cm2 (p0.05. Data indicate that the LAB biopreservative may assist beef safety protection when utilized within a multi-intervention beef harvest, fabrication, and aging process.

  12. Production of reuterin in a fermented milk product by Lactobacillus reuteri: Inhibition of pathogens, spoilage microorganisms, and lactic acid bacteria.

    Science.gov (United States)

    Ortiz-Rivera, Y; Sánchez-Vega, R; Gutiérrez-Méndez, N; León-Félix, J; Acosta-Muñiz, C; Sepulveda, D R

    2017-06-01

    We assessed the antimicrobial activity of reuterin produced in vitro in glycerol aqueous solutions in situ by Lactobacillus reuteri ATCC 53608 as part of a fermented milk product against starter (Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus), spoilage (Penicillium expansum), pathogenic (Staphylococcus aureus Salmonella enterica ssp. enterica, and Listeria monocytogenes), and pathogen surrogate (Escherichia coli DH5α) microorganisms. We also assayed the influence of cold storage (28 d at 4°C) and reuterin on the color and rheology of the fermented milk product. We obtained maximum reuterin concentrations of 107.5 and 33.97 mM in glycerol aqueous solution and fermented milk product, respectively. Reuterin was stable throughout its refrigerated shelf life. Gram-positive microorganisms were more resistant to reuterin than gram-negative microorganisms. Penicillium expansum and Lactobacillus reuteri ATCC 53608 survived at concentrations up to 10 and 8.5 mM, respectively. Escherichia coli DH5α was the most sensitive to reuterin (0.9 mM). The presence of reuterin did not cause relevant changes in the quality parameters of the fermented milk product, including pH, acidity, soluble solids, color, and rheological aspects (storage and loss moduli and viscosity). This study demonstrated the viability of using Lactobacillus reuteri ATCC 53608 as a biopreservative in a fermented milk product through reuterin synthesis, without drastically modifying its quality parameters. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  13. Selectivity of Inhibition of N-Succinyl-l,l-Diaminopimelic Acid Desuccinylase in Bacteria: The product of dapE-gene Is Not the Target of l-Captopril Antimicrobial Activity.

    Science.gov (United States)

    Uda, Narasimha Rao; Creus, Marc

    2011-01-01

    The emergence of bacterial strains that are resistant to virtually all currently available antibiotics underscores the importance of developing new antimicrobial compounds. N-succinyl-l,l-diaminopimelic acid desuccinylase (DapE) is a metallohydrolase involved in the meso-diaminopimelate (mDAP)/lysine biosynthetic pathway necessary for lysine biosynthesis and for building the peptidoglycan cell wall. Because DapE is essential for Gram-negative and some Gram-positive bacteria, DapE has been proposed as a good target for antibiotic development. Recently, l-captopril has been suggested as a lead compound for inhibition of DapE, although its selectivity for this enzyme target in bacteria remains unclear (Gillner et al. (2009)). Here, we tested the selectivity of l-captopril against DapE in bacteria. Since DapE knockout strains of gram-negative bacteria are viable upon chemical supplementation with mDAP, we reasoned that the antimicrobial activity of compounds targeting DapE should be abolished in mDAP-containing media. Although l-captopril had modest antimicrobial activity in Escherichia coli and in Salmonella enterica, to our surprise, inhibition of bacterial growth was independent both of mDAP supplementation and DapE over-expression. We conclude that DapE is not the main target of l-captopril inhibition in these bacteria. The methods implemented here will be useful for screening DapE-selective antimicrobial compounds directly in bacterial cultures.

  14. Genetics of Lactic Acid Bacteria

    Science.gov (United States)

    Zagorec, Monique; Anba-Mondoloni, Jamila; Coq, Anne-Marie Crutz-Le; Champomier-Vergès, Marie-Christine

    Many meat (or fish) products, obtained by the fermentation of meat originating from various animals by the flora that naturally contaminates it, are part of the human diet since millenaries. Historically, the use of bacteria as starters for the fermentation of meat, to produce dry sausages, was thus performed empirically through the endogenous micro-biota, then, by a volunteer addition of starters, often performed by back-slopping, without knowing precisely the microbial species involved. It is only since about 50 years that well defined bacterial cultures have been used as starters for the fermentation of dry sausages. Nowadays, the indigenous micro-biota of fermented meat products is well identified, and the literature is rich of reports on the identification of lactic acid bacteria (LAB) present in many traditional fermented products from various geographical origin, obtained without the addition of commercial starters (See Talon, Leroy, & Lebert, 2007, and references therein).

  15. Antifungal Capacity of Lactic Acid Bacteria Isolated From Salad ...

    African Journals Online (AJOL)

    This study explores the use of lactic acid bacteria from fresh salad vegetables to inhibit fungal growth. The antifungal assay was done using the agar well diffusion method as reported by Schillinger and Lucke (1989). The largest zone of inhibition (25mm) was recorded by the antagonistic activity of the isolate identified to ...

  16. DEOXYRIBONUCLEIC ACID HYBRIDS OF ACETIC ACID BACTERIA

    Science.gov (United States)

    De Ley, J.; Friedman, S.

    1964-01-01

    De Ley, J. (State University, Ghent, Belgium), and S. Friedman. Deoxyribonucleic acid hybrids of acetic acid bacteria. J. Bacteriol. 88:937–945. 1964.—Deuterated N15-labeled deoxyribonucleic acid (DNA) from Acetobacter aceti (mesoxydans 4) forms hybrids with ordinary DNA from other species of this genus (A. xylinum, A. pasteurianus, A. estunensis, and possibly A. xylinoides) when the guanine plus cytosine base composition does not vary by more than 1 to 2%. Beyond this limit (A. aceti Ch31 and A. muciparus 5) no hybrids are formed. The hybrids are apparently derived from an asymmetrical part of the compositional distribution. The results lend strength to the concept of a genetic species rather than to a division of a genus into sharply separated species, based on small phenotypic differences. Taxonomic implications are discussed. PMID:14219057

  17. Isolation, characterization and identification of lactic acid bacteria ...

    African Journals Online (AJOL)

    Changes in pH, titratable acidity, Enterobacteriaceae, aerobic mesophiles, lactic acid bacteria (LAB) and yeast counts were investigated during borde fermentation. A rapid decrease in pH was associated with accelerated growth rate of LAB and inhibition of Enterobacteriaceae. Wide diversities of LAB strains were present at ...

  18. Lactic Acid Bacteria in the Gut

    NARCIS (Netherlands)

    Stolaki, M.; Vos, de W.M.; Kleerebezem, M.; Zoetendal, E.G.

    2012-01-01

    From all bacterial groups, the lactic acid bacteria (LAB) are probably the group of bacteria that is most associated with human lifestyle. The term LAB mainly refers to the ability of these organisms to convert sugars to lactic acid. The LAB comprise non-sporing, aerotolerant, coccus or rod-shaped,

  19. Energy transduction in lactic acid bacteria

    NARCIS (Netherlands)

    Poolman, Bert

    In the discovery of some general principles of energy transduction, lactic acid bacteria have played an important role. In this review, the energy transducing processes of lactic acid bacteria are discussed with the emphasis on the major developments of the past 5 years. This work not only includes

  20. Bacteriocin and cellulose production by lactic acid bacteria isolated ...

    African Journals Online (AJOL)

    Sixteen colonies of lactic acid bacteria (LAB) were selected and screened for their ability to produce bacteriocin by agar well diffusion method using the supernatant of centrifuged test cultures. Four isolates inhibited the growth of Listeria monocytogenes and Escherichia coli. Lactobacillus plantarum (6) and Lactobacillus ...

  1. Genetics of proteinases of lactic acid bacteria

    NARCIS (Netherlands)

    Kok, Jan; Venema, Gerhardus

    Because it is essential for good growth with concomitant rapid acid production, and for the production of flavorous peptides and amino acids, the proteolytic ability of lactic acid bacteria is of crucial importance for reliable dairy product quality. In view of this importance, considerable research

  2. Lactic acid bacteria: microbiological and functional aspects

    National Research Council Canada - National Science Library

    Lahtinen, Sampo

    2012-01-01

    "Updated with the substantial progress made in lactic acid and bacteria research since the third edition, this fourth volume discusses improved insights in genetics and new molecular biological techniques...

  3. Discovering lactic acid bacteria by genomics

    NARCIS (Netherlands)

    Klaenhammer, T; Altermann, E; Arigoni, F; Bolotin, A; Breidt, F; Broadbent, J; Cano, R; Chaillou, S; Deutscher, J; Gasson, M; van de Guchte, M; Guzzo, J; Hartke, A; Hawkins, T; Hols, P; Hutkins, R; Kleerebezem, M; Kok, J; Kuipers, O; Maguin, E; McKay, L; Mills, D; Nauta, A; Overbeek, R; Pel, H; Pridmore, D; Saier, M; van Sinderen, D; Sorokin, A; Steele, J; O'Sullivan, D; de Vos, W; Weimer, B; Zagorec, M; Siezen, R

    This review summarizes a collection of lactic acid bacteria that are now undergoing genomic sequencing and analysis. Summaries are presented on twenty different species, with each overview discussing the organisms fundamental and practical significance, environmental habitat, and its role in

  4. Potentials of Exopolysaccharides from Lactic Acid Bacteria

    OpenAIRE

    Patel, Seema; Majumder, Avishek; Goyal, Arun

    2011-01-01

    Recent research in the area of importance of microbes has revealed the immense industrial potential of exopolysaccharides and their derivative oligosaccharides from lactic acid bacteria. However, due to lack of adequate technological knowledge, the exopolysaccharides have remained largely under exploited. In the present review, the enormous potentials of different types of exopolysaccharides from lactic acid bacteria are described. This also summarizes the recent advances in the applications ...

  5. Probiotic properties of lactic acid bacteria isolated from human milk.

    Science.gov (United States)

    Reis, N A; Saraiva, M A F; Duarte, E A A; de Carvalho, E A; Vieira, B B; Evangelista-Barreto, N S

    2016-09-01

    The objective of this study was to identify and characterize lactic acid bacteria isolated from human milk, with an emphasis on their probiotic properties. The strains were tested for their ability to inhibit growth of Enterococcus faecalis, Salmonella enterica subsp. enterica serotype Enteritidis, Listeria monocytogenes, Staphylococcus aureus and Escherichia coli, as well as for susceptibility to antimicrobial agents and for acid pH and bile salt tolerance. Gram-positive and catalase-negative were selected and identified as Enterococcus (83·3%) after sequencing the 16S rDNA gene. All the isolates inhibited growth of Ent. faecalis and S. serotype Enteritidis, 97% inhibited growth of L. monocytogenes and Staph. aureus and 78·8% inhibited growth of E. coli. Most of the isolates were resistant to gentamicin (50%) and vancomycin (47%). Twelve isolates grew when subjected to pH 3·0 and 0·1% bile salts. At lower pH (2·5-2·0), Ent. faecalis F1 and Weissella confusa F8 were more efficient. It was possible to isolate from human milk the lactic acid bacteria with potential for use as probiotics. Lactic acid bacteria isolated of nursing mothers have probiotic properties. © 2016 The Society for Applied Microbiology.

  6. Genetics of proteinases of lactic acid bacteria

    OpenAIRE

    Kok, Jan; Venema, Gerhardus

    1988-01-01

    Because it is essential for good growth with concomitant rapid acid production, and for the production of flavorous peptides and amino acids, the proteolytic ability of lactic acid bacteria is of crucial importance for reliable dairy product quality. In view of this importance, considerable research has been carried out to characterize the enzymes involved. The intensified genetic research in the lactic acid streptococci and the development of gene cloning systems for these organisms have res...

  7. Characterization of acetic acid bacteria in "traditional balsamic vinegar".

    Science.gov (United States)

    Gullo, Maria; Caggia, Cinzia; De Vero, Luciana; Giudici, Paolo

    2006-02-01

    This study evaluated the glucose tolerance of acetic acid bacteria strains isolated from Traditional Balsamic Vinegar. The results showed that the greatest hurdle to acetic acid bacteria growth is the high sugar concentration, since the majority of the isolated strains are inhibited by 25% of glucose. Sugar tolerance is an important technological trait because Traditional Balsamic Vinegar is made with concentrated cooked must. On the contrary, ethanol concentration of the cooked and fermented must is less significant for acetic acid bacteria growth. A tentative identification of the isolated strains was done by 16S-23S-5S rDNA PCR/RFLP technique and the isolated strains were clustered: 32 strains belong to Gluconacetobacter xylinus group, two strains to Acetobacter pasteurianus group and one to Acetobacter aceti.

  8. Comparative genomics of the lactic acid bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Makarova, K.; Slesarev, A.; Wolf, Y.; Sorokin, A.; Mirkin, B.; Koonin, E.; Pavlov, A.; Pavlova, N.; Karamychev, V.; Polouchine, N.; Shakhova, V.; Grigoriev, I.; Lou, Y.; Rokhsar, D.; Lucas, S.; Huang, K.; Goodstein, D. M.; Hawkins, T.; Plengvidhya, V.; Welker, D.; Hughes, J.; Goh, Y.; Benson, A.; Baldwin, K.; Lee, J. -H.; Diaz-Muniz, I.; Dosti, B.; Smeianov, V; Wechter, W.; Barabote, R.; Lorca, G.; Altermann, E.; Barrangou, R.; Ganesan, B.; Xie, Y.; Rawsthorne, H.; Tamir, D.; Parker, C.; Breidt, F.; Broadbent, J.; Hutkins, R.; O' Sullivan, D.; Steele, J.; Unlu, G.; Saier, M.; Klaenhammer, T.; Richardson, P.; Kozyavkin, S.; Weimer, B.; Mills, D.

    2006-06-01

    Lactic acid-producing bacteria are associated with various plant and animal niches and play a key role in the production of fermented foods and beverages. We report nine genome sequences representing the phylogenetic and functional diversity of these bacteria. The small genomes of lactic acid bacteria encode a broad repertoire of transporters for efficient carbon and nitrogen acquisition from the nutritionally rich environments they inhabit and reflect a limited range of biosynthetic capabilities that indicate both prototrophic and auxotrophic strains. Phylogenetic analyses, comparison of gene content across the group, and reconstruction of ancestral gene sets indicate a combination of extensive gene loss and key gene acquisitions via horizontal gene transfer during the coevolution of lactic acid bacteria with their habitats.

  9. The proteolytic system of lactic acid bacteria.

    Science.gov (United States)

    Mayo, B

    1993-12-01

    Lactic acid bacteria are widely used throughout the world, empirically or deliberately, in the manufacturing of several food and feed stuffs, including milk products (such as cheese, butter, yoghurt, buttermilk, etc.), fermented vegetables (pickles, olives and sauerkraut), sausages, sourdough bread and silage, due to their ability to convert sugars into lactic acid. Of these, dairy products are of outstanding economic importance. Starter cultures used in the dairy industry are mixtures of carefully selected lactic acid bacteria which are added to the milk to fulfil the desired fermentation. Dairy starter cultures must reach high densities in milk in order to produce lactic acid at the required rates for manufacturing. Under these conditions, amino acids supply becomes limitant due to their scarce concentration in milk and to the auxotrophies shown by many starter bacteria. This implies the necessity of a proteolytic system, able to degrade the most abundant protein in milk, casein, into assimilable amino acids and peptides. Casein degradation and utilization require the concerted action of proteinases, peptidases and amino acid and peptide uptake systems. This whole set of enzymes constitutes the proteolytic system. In this article an overview of the recent biochemical and genetic data on the proteolytic system of lactic acid bacteria will be presented.

  10. CHARACTERIZATION OF LACTIC ACID BACTERIA ISOLATED FROM SUMBAWA MARE MILK

    Directory of Open Access Journals (Sweden)

    Nengah Sujaya

    2008-06-01

    Full Text Available A study was carried out to isolate and characterize lactic acid bacteria (LAB from the Sumbawa mares milk The Isolation of LAB was conducted in Man Rogosa Sharpe (MRS agar. The isolates were characterized by standard methods, such as Gram staining, cell morphology study and fermentation activities. The ability of the isolates to inhibit some pathogenic bacteria was studied by dual culture assay. Isolates showing the widest spectrum of inhibiting pathogenic bacteria were further identified using API 50 CHL. The results showed that Sumbawa mare milk was dominated by lactobacilli and weisella/leuconostoc. As many as 26 out 36 isolates belong to homofermentative lactobacilli and another 10 isolates belong to both heterofermentative lactobacilli and weissella or leuconostoc. Twenty four isolates inhibited the growth of Escherichia coli 25922, Shigela flexneri, Salmonella typhimurium, and Staphylococcus aureus 29213. Two promising isolates with the widest spectrum of inhibiting pathogenic bacteria, Lactobacillus sp. SKG34 and Lactobacillus sp. SKG49, were identified respectively as Lactobacillus rhamnosus SKG34 and Lactobacillus ramnosus SKG49. These two isolates were specific strains of the sumbawa mare milk and are very potential to be developed as probiotic for human.

  11. Antifungal Activity of Selected Lactic Acid Bacteria and Propionic Acid Bacteria against Dairy-Associated Spoilage Fungi

    DEFF Research Database (Denmark)

    Aunsbjerg, Stina Dissing

    Bacterial cultures of lactic and propionic acid bacteria are widely used in fermented products including dairy products. Spoilage fungi may constitute a quality and safety issue in these products. The antifungal properties of some lactic and propionic acid bacteria make them potential candidates...... diacetyl and lactic acid, 6 antifungal hydroxy acids were identified. Of these, 3 have previously been reported from antifungal lactic acid bacteria, whereas the other 3 hydroxy acids have not previously been reported produced by antifungal lactic acid bacteria....

  12. Polyphasic taxonomic characterization of lactic acid bacteria ...

    African Journals Online (AJOL)

    Polyphasic taxonomic characterization of lactic acid bacteria isolated from spontaneous sorghum fermentations used to produce ting, a traditional South African food. ... The results of these analyses showed that ting fermentation involved at least three different species of LAB, i.e. Lactobacillus fermentum, L. plantarum

  13. Stress physiology of lactic acid bacteria

    NARCIS (Netherlands)

    Papadimitriou, Konstantinos; Alegría, Ángel; Bron, Peter A.; Angelis, De Maria; Gobbetti, Marco; Kleerebezem, Michiel; Lemos, José A.; Linares, Daniel M.; Ross, Paul; Stanton, Catherine; Turroni, Francesca; Sinderen, Van Douwe; Varmanen, Pekka; Ventura, Marco; Zúñiga, Manuel; Tsakalidou, Effie; Kok, Jan

    2016-01-01

    Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and

  14. Stress Physiology of Lactic Acid Bacteria

    NARCIS (Netherlands)

    Papadimitriou, Konstantinos; Alegría, Ángel; Bron, Peter A; de Angelis, Maria; Gobbetti, Marco; Kleerebezem, Michiel; Lemos, José A; Linares, Daniel M; Ross, Paul; Stanton, Catherine; Turroni, Francesca; van Sinderen, Douwe; Varmanen, Pekka; Ventura, Marco; Zúñiga, Manuel; Tsakalidou, Effie; Kok, Jan

    Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the

  15. Exopolysaccharides produced by lactic acid bacteria

    NARCIS (Netherlands)

    Caggianiello, Graziano; Kleerebezem, Michiel; Spano, Giuseppe

    2016-01-01

    A wide range of lactic acid bacteria (LAB) is able to produce capsular or extracellular polysaccharides, with various chemical compositions and properties. Polysaccharides produced by LAB alter the rheological properties of the matrix in which they are dispersed, leading to typically viscous and

  16. Why engineering lactic acid bacteria for biobutanol

    Science.gov (United States)

    The Gram-positive Lactic acid bacteria (LAB) are considered attractive biocatalysts for biomass to biofuels for several reasons. They have GRAS (Generally Recognized As Safe) status that are acceptable in food, feed, and medical applications. LAB are fermentative: selected strains are capable of f...

  17. The proteolytic systems of lactic acid bacteria

    NARCIS (Netherlands)

    Kunji, Edmund R.S.; Mierau, Igor; Hagting, Anja; Poolman, Bert; Konings, Wil N.

    1996-01-01

    Proteolysis in dairy lactic acid bacteria has been studied in great detail by genetic, biochemical and ultrastructural methods. From these studies the picture emerges that the proteolytic systems of lactococci and lactobacilli are remarkably similar in their components and mode of action. The

  18. Proteolytic enzymes of lactic acid bacteria

    NARCIS (Netherlands)

    Law, J; Haandrikman, A

    The proteolytic system of lactic acid bacteria is essential for their growth in milk and contributes significantly to flavour development in fermented milk products where these microorganisms are used as starter cultures. The proteolytic system is composed of proteinases which initially cleave the

  19. Genera and species in acetic acid bacteria.

    Science.gov (United States)

    Yamada, Yuzo; Yukphan, Pattaraporn

    2008-06-30

    Taxonomic studies of acetic acid bacteria were historically surveyed. The genus Acetobacter was first introduced in 1898 with a single species, Acetobacter aceti. The genus Gluconobacter was proposed in 1935 for strains with intense oxidation of glucose to gluconic acid rather than oxidation of ethanol to acetic acid and no oxidation of acetate. The genus "Acetomonas" was described in 1954 for strains with polar flagellation and no oxidation of acetate. The proposals of the two generic names were due to confusion, and "Acetomonas" was a junior subjective synonym of Gluconobacter. The genus Acetobacter was in 1984 divided into two subgenera, Acetobacter and Gluconoacetobacter. The latter was elevated to the genus Gluconacetobacter in 1998. In the acetic acid bacteria, ten genera are presently recognized and accommodated to the family Acetobacteraceae, the Alphaproteobacteria: Acetobacteer, Gluconobacter, Acidomonas, Gluconacetobacter, Asaia, Kozakia, Swaminathania, Saccharibacter, Neoasaia and Granulibacter. In contrast, the genus Frateuria, strains of which were once named 'pseudacetic acid bacteria', was classified into the Gammaproteobacteria. The genus Gluconacetobacter was phylogenetically divided into two groups: the Gluconacetobacter liquefaciens group and the Gluconacetobacter xylinus group. The two groups were discussed taxonomically.

  20. Identification of Lactic Acid Bacteria and Propionic Acid Bacteria using FTIR Spectroscopy and Artificial Neural Networks

    OpenAIRE

    Dziuba, Bartłomiej; Nalepa, Beata

    2012-01-01

    In the present study, lactic acid bacteria and propionic acid bacteria have been identified at the genus level with the use of artificial neural networks (ANNs) and Fourier transform infrared spectroscopy (FTIR). Bacterial strains of the genera Lactobacillus, Lactococcus, Leuconostoc, Streptococcus and Propionibacterium were analyzed since they deliver health benefits and are routinely used in the food processing industry. The correctness of bacterial identification by ANNs and FTIR was evalu...

  1. Bacteriocins From Lactic Acid Bacteria: Interest For Food Products Biopreservation

    OpenAIRE

    Dortu, C.; Thonart, Philippe

    2009-01-01

    Bacteriocins from lactic acid bacteria: interest for food products biopreservation. Bacteriocins from lactic acid bacteria are low molecular weight antimicrobial peptides. They have inhibitory activity against the bacteria that are closed related to the producer strains and a narrow inhibitory spectrum. Nevertheless, most of them have activity against some food-born pathogenic bacteria as Listeria monocytogenes. The application of bacteriocins or bacteriocin producing lactic acid bacteria in ...

  2. Characterization of anti-listerial lactic acid bacteria isolated from Thai fermented fish products

    DEFF Research Database (Denmark)

    Østergaard, Anya; Embarek, Peter Karim Ben; Wedell-Neergaard, C.

    1998-01-01

    Thai fermented fish products were screened for lactic acid bacteria capable of inhibiting Listeria sp. (Listeria innocua). Of 4150 assumed lactic acid bacteria colonies from MRS agar plates that were screened by an agar-overlay method 58 (1.4%) were positive. Forty four of these strains were...... further characterized and 43 strains were inhibitory against Listeria monocytogenes. The strains were inhibitory to other Gram- positive (lactic acid) bacteria probably because of production of bacteriocins. All 44 strains inhibited both Vibrio cholerae and Vibrio parahaemolyticus and 37 were inhibitory...... to a mesophilic fish spoilage bacterium tan Aeromonas sp.). Inhibition of Gram-negative bacteria was attributed to production of lactic acid. Most strains were identified as Lactobacillus spp., and all grew well at ambient temperatures (25-37 degrees C) and tolerated up to 6.5% NaCl. Glucose was fermented rapidly...

  3. Extractive Fermentation of Lactic Acid in Lactic Acid Bacteria Cultivation: A Review

    Science.gov (United States)

    Othman, Majdiah; Ariff, Arbakariya B.; Rios-Solis, Leonardo; Halim, Murni

    2017-01-01

    Lactic acid bacteria are industrially important microorganisms recognized for their fermentative ability mostly in their probiotic benefits as well as lactic acid production for various applications. Nevertheless, lactic acid fermentation often suffers end-product inhibition which decreases the cell growth rate. The inhibition of lactic acid is due to the solubility of the undissociated lactic acid within the cytoplasmic membrane and insolubility of dissociated lactate, which causes acidification of cytoplasm and failure of proton motive forces. This phenomenon influences the transmembrane pH gradient and decreases the amount of energy available for cell growth. In general, the restriction imposed by lactic acid on its fermentation can be avoided by extractive fermentation techniques, which can also be exploited for product recovery. PMID:29209295

  4. Extractive Fermentation of Lactic Acid in Lactic Acid Bacteria Cultivation: A Review.

    Science.gov (United States)

    Othman, Majdiah; Ariff, Arbakariya B; Rios-Solis, Leonardo; Halim, Murni

    2017-01-01

    Lactic acid bacteria are industrially important microorganisms recognized for their fermentative ability mostly in their probiotic benefits as well as lactic acid production for various applications. Nevertheless, lactic acid fermentation often suffers end-product inhibition which decreases the cell growth rate. The inhibition of lactic acid is due to the solubility of the undissociated lactic acid within the cytoplasmic membrane and insolubility of dissociated lactate, which causes acidification of cytoplasm and failure of proton motive forces. This phenomenon influences the transmembrane pH gradient and decreases the amount of energy available for cell growth. In general, the restriction imposed by lactic acid on its fermentation can be avoided by extractive fermentation techniques, which can also be exploited for product recovery.

  5. Extractive Fermentation of Lactic Acid in Lactic Acid Bacteria Cultivation: A Review

    Directory of Open Access Journals (Sweden)

    Majdiah Othman

    2017-11-01

    Full Text Available Lactic acid bacteria are industrially important microorganisms recognized for their fermentative ability mostly in their probiotic benefits as well as lactic acid production for various applications. Nevertheless, lactic acid fermentation often suffers end-product inhibition which decreases the cell growth rate. The inhibition of lactic acid is due to the solubility of the undissociated lactic acid within the cytoplasmic membrane and insolubility of dissociated lactate, which causes acidification of cytoplasm and failure of proton motive forces. This phenomenon influences the transmembrane pH gradient and decreases the amount of energy available for cell growth. In general, the restriction imposed by lactic acid on its fermentation can be avoided by extractive fermentation techniques, which can also be exploited for product recovery.

  6. Freeze-drying of lactic acid bacteria.

    Science.gov (United States)

    Fonseca, Fernanda; Cenard, Stéphanie; Passot, Stéphanie

    2015-01-01

    Lactic acid bacteria are of great importance for the food and biotechnology industry. They are widely used as starters for manufacturing food (e.g., yogurt, cheese, fermented meats, and vegetables) and probiotic products, as well as for green chemistry applications. Freeze-drying or lyophilization is a convenient method for preservation of bacteria. By reducing water activity to values below 0.2, it allows long-term storage and low-cost distribution at suprazero temperatures, while minimizing losses in viability and functionality. Stabilization of bacteria via freeze-drying starts with the addition of a protectant solution to the bacterial suspension. Freeze-drying includes three steps, namely, (1) freezing of the concentrated and protected cell suspension, (2) primary drying to remove ice by sublimation, and (3) secondary drying to remove unfrozen water by desorption. In this chapter we describe a method for freeze-drying of lactic acid bacteria at a pilot scale, thus allowing control of the process parameters for maximal survival and functionality recovery.

  7. Antibiotic resistance of lactic acid bacteria

    OpenAIRE

    Bulajić Snežana; Mijačević Zora; Savić-Radovanović Radoslava

    2008-01-01

    Knowledge on the antibiotic resistance of lactic acid bacteria is still limited, possibly because of the large numbers of genera and species encountered in this group, as well as variances in their resistance spectra. The EFSA considers antibiotic resistances, especially transferable resistances, an important decision criterion for determining a strain's QPS status. There are no approved standards for the phenotypic or genotypic evaluation of antibiotic resistances in food isolat...

  8. Stress Physiology of Lactic Acid Bacteria

    OpenAIRE

    Papadimitriou, Konstantinos; Alegría, Ángel; Bron, Peter A.; de Angelis, Maria; Gobbetti, Marco; Kleerebezem, Michiel; Lemos, José A.; Linares, Daniel M.; Ross, Paul; Stanton, Catherine; Turroni, Francesca; van Sinderen, Douwe; Varmanen, Pekka; Ventura, Marco; Zúñiga, Manuel

    2016-01-01

    Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diver...

  9. Progress in engineering acid stress resistance of lactic acid bacteria.

    Science.gov (United States)

    Wu, Chongde; Huang, Jun; Zhou, Rongqing

    2014-02-01

    Lactic acid bacteria (LAB) are widely used for the production of a variety of fermented foods, and are considered as probiotic due to their health-promoting effect. However, LAB encounter various environmental stresses both in industrial fermentation and application, among which acid stress is one of the most important survival challenges. Improving the acid stress resistance may contribute to the application and function of probiotic action to the host. Recently, the advent of genomics, functional genomics and high-throughput technologies have allowed for the understanding of acid tolerance mechanisms at a systems level, and many method to improve acid tolerance have been developed. This review describes the current progress in engineering acid stress resistance of LAB. Special emphasis is placed on engineering cellular microenvironment (engineering amino acid metabolism, introduction of exogenous biosynthetic capacity, and overproduction of stress response proteins) and maintaining cell membrane functionality. Moreover, strategies to improve acid tolerance and the related physiological mechanisms are also discussed.

  10. [Methanotrophic bacteria of acid sphagnum bogs].

    Science.gov (United States)

    Dedysh, S N

    2002-01-01

    Acid sphagnum bogs cover a considerable part of the territory of Russia and are an important natural source of biogenic methane, which is formed in their anaerobic layers. A considerable portion of this methane is consumed in the aerobic part of the bog profile by acidophilic methanotrophic bacteria, which comprise the methane filter of sphagnum bogs and decrease CH4 emission to the atmosphere. For a long time, these bacteria escaped isolation, which became possible only after the elucidation of the optimal conditions of their functioning in situ: pH 4.5 to 5.5; temperature, from 15 to 20 degrees C; and low salt concentration in the solution. Reproduction of these conditions and rejection of earlier used media with a high content of biogenic elements allowed methanotrophic bacteria of two new genera and species--Methylocella palustris and Methylocapsa acidophila--to be isolated from the peat of sphagnum bogs of the northern part of European Russia and West Siberia. These bacteria are well adapted to the conditions in cold, acid, oligotrophic sphagnum bogs. They grow in a pH range of 4.2-7.5 with an optimum at 5.0-5.5, prefer moderate temperatures (15-25 degrees C) and media with a low content of mineral salts (200-500 mg/l), and are capable of active nitrogen fixation. Design of fluorescently labeled 16S rRNA-targeted oligonucleotide probes for the detection of Methylocella palustris and Methylocapsa acidophila and their application to the analysis of sphagnum peat samples showed that these bacteria represent dominant populations of methanotrophs with a density of 10(5)-10(6) cells/g peat. In addition to Methylocella and Methylocapsa populations, one more abundant population of methanotrophs was revealed (10(6) cells/g peat), which were phylogenetically close to the genus Methylocystis.

  11. Potential of lactic acid bacteria in aflatoxin risk mitigation.

    Science.gov (United States)

    Ahlberg, Sara H; Joutsjoki, Vesa; Korhonen, Hannu J

    2015-08-17

    Aflatoxins (AF) are ubiquitous mycotoxins contaminating food and feed. Consumption of contaminated food and feed can cause a severe health risk to humans and animals. A novel biological method could reduce the health risks of aflatoxins through inhibiting mold growth and binding aflatoxins. Lactic acid bacteria (LAB) are commonly used in fermented food production. LAB are known to inhibit mold growth and, to some extent, to bind aflatoxins in different matrices. Reduced mold growth and aflatoxin production may be caused by competition for nutrients between bacterial cells and fungi. Most likely, binding of aflatoxins depends on environmental conditions and is strain-specific. Killed bacteria cells possess consistently better binding abilities for aflatoxin B1 (AFB1) than viable cells. Lactobacilli especially are relatively well studied and provide noticeable possibilities in binding of aflatoxin B1 and M1 in food. It seems that binding is reversible and that bound aflatoxins are released later on (Haskard et al., 2001; Peltonen et al., 2001). This literature review suggests that novel biological methods, such as lactic acid bacteria, show potential in mitigating toxic effects of aflatoxins in food and feed. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. In vitro screening of soil bacteria for inhibiting phytopathogenic fungi ...

    African Journals Online (AJOL)

    At present, the greatest interest resides with the development and application of specific biocontrol agent for the control of diseases on plant and this form the focus of this work. Several soil bacteria were evaluated in vitro for their effectiveness on the basis of their ability to suppress fungi in plate inhibition assays. 51 strains ...

  13. Biosynthesis of myristic acid in luminescent bacteria

    International Nuclear Information System (INIS)

    Byers, D.M.

    1987-01-01

    In vivo pulse-label studies have demonstrated that luminescent bacteria can provide myritic acid (14:0) required for the synthesis of the luciferase substrate myristyl aldehyde. Luminescent wild type Vibrio harveyi incubated with [ 14 C] acetate in a nutrient-depleted medium accumulated substantial tree [ 14 C]fatty acid (up to 20% of the total lipid label). Radio-gas chromatography revealed that > 75% of the labeled fatty acid is 14:0. No free fatty acid was detected in wild type cells labeled prior to the development of bioluminescence in the exponential growth phase, or in a dark mutant of V. harveyi (mutant M17) that requires exogenous 14:0 for light emission. The preferential accumulation of 14:0 was not observed when wild type cells were labeled with [ 14 C]acetate in regular growth medium. Moreover, all V. harveyi strains exhibited similar fatty acid mass compositions regardless of the state of bioluminescence. Since earlier work has shown that a luminescence-related acyltransferase (defective in the M17 mutant) can catalyze the deacylation of fatty acyl-acyl carrier protein in vitro, the present results are consistent with a model in which this enzyme diverts 14:0 to the luminescence system during fatty acid biosynthesis. Under normal conditions, the supply of 14:0 by this pathway is tightly regulated such that bioluminescence development does not significantly alter the total fatty acid composition

  14. Beneficial effects of antioxidative lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Hisako Nakagawa

    2017-01-01

    Full Text Available Oxidative stress is caused by exposure to reactive oxygen intermediates. The oxidative damage of cell components such as proteins, lipids, and nucleic acids one of the important factors associated with diabetes mellitus, cancers and cardiovascular diseases. This occurs as a result of imbalance between the generations of oxygen derived radicals and the organism’s antioxidant potential. The amount of oxidative damage increases as an organism ages and is postulated to be a major causal factor of senescence. To date, many studies have focused on food sources, nutrients, and components that exert antioxidant activity in worms, flies, mice, and humans. Probiotics, live microorganisms that when administered in adequate amounts provide many beneficial effects on the human health, have been attracting growing interest for their health-promoting effects, and have often been administered in fermented milk products. In particular, lactic acid bacteria (LAB are known to conferre physiologic benefits. Many studies have indicated the antioxidative activity of LAB. Here we review that the effects of lactic acid bacteria to respond to oxidative stress, is connected to oxidative-stress related disease and aging.

  15. Effects of volatile fatty acid concentrations on methane yield and methanogenic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yuanyuan; Zhang, Yanlin; Wang, Jianbo; Meng, Liang [Engineering Technology Academy, Huazhong Agriculture University, Wuhan 430070 (China)

    2009-05-15

    Volatile fatty acids (VFAs) are important mid-products in the production of methane, and their concentrations affect the efficiency of fermentation. However, their effects on methane yield and methanogenic bacteria growth have been less extensively studied. To address these effects, acetic acid, propionic acid, butyric acid and ethanol were used as substrates and an L{sub 9}(3{sup 4}) orthogonal table was adopted to design anaerobic digestion tests. When the highest concentrations of ethanol, acetic acid and butyric acid were 2400, 2400 and 1800 mg L{sup -1}, respectively, there was no significant inhibition of the activity of methanogenic bacteria. However, when the propionic acid concentration was increased to 900 mg L{sup -1}, significant inhibition appeared, the bacteria concentration decreased from 6 x 10{sup 7} to 0.6-1 x 10{sup 7} ml{sup -1} and their activity would not reconvert. These effects resulted in the accumulation of ethanol and VFAs, and the total methane yield consequently became very low (<321 ml). The original propionic acid concentration had a significant inhibitory effect on methanogenic bacteria growth (P < 0.01). An optimization analysis showed that ethanol, acetic acid, propionic acid and butyric acid at concentrations of 1600, 1600, 300 and 1800 mg L{sup -1}, respectively, led to the maximum accumulative methane yield of 1620 ml and the maximum methanogenic bacteria concentration of 7.3 x 10{sup 8} ml{sup -1}. (author)

  16. Mechanisms and improvement of acid resistance in lactic acid bacteria.

    Science.gov (United States)

    Wang, Chao; Cui, Yanhua; Qu, Xiaojun

    2018-03-01

    Lactic acid bacteria (LAB) can take advantage of fermentable carbohydrates to produce lactic acid. They are proverbially applied in industry, agricultural production, animal husbandry, food enterprise, pharmaceutical engineering and some other important fields, which are closely related to human life. For performing the probiotic functions, LAB have to face the low pH environment of the gastrointestinal tract. Therefore, acid resistance of LAB is of great importance not only for their own growth, but also for fermentation and preparation of probiotic products. Recent research studies on acid resistance mechanisms of LAB are mainly focused on neutralization process, biofilm and cell density, proton pump, protection of macromolecules, pre-adaptation and cross-protection, and effect of solutes. In this context, biotechnological strategies such as synthetic biology, genome shuffling, high pressure homogenization and adaptive laboratory evolution were also used to improve the acid resistance of LAB to respond to constantly changing low pH environment.

  17. The effect of lactic acid bacteria on cocoa bean fermentation.

    Science.gov (United States)

    Ho, Van Thi Thuy; Zhao, Jian; Fleet, Graham

    2015-07-16

    Cocoa beans (Theobroma cacao L.) are the raw material for chocolate production. Fermentation of cocoa pulp by microorganisms is crucial for developing chocolate flavor precursors. Yeasts conduct an alcoholic fermentation within the bean pulp that is essential for the production of good quality beans, giving typical chocolate characters. However, the roles of bacteria such as lactic acid bacteria and acetic acid bacteria in contributing to the quality of cocoa bean and chocolate are not fully understood. Using controlled laboratory fermentations, this study investigated the contribution of lactic acid bacteria to cocoa bean fermentation. Cocoa beans were fermented under conditions where the growth of lactic acid bacteria was restricted by the use of nisin and lysozyme. The resultant microbial ecology, chemistry and chocolate quality of beans from these fermentations were compared with those of indigenous (control) fermentations. The yeasts Hanseniaspora guilliermondii, Pichia kudriavzevii, Kluyveromyces marxianus and Saccharomyces cerevisiae, the lactic acid bacteria Lactobacillus plantarum, Lactobacillus pentosus and Lactobacillus fermentum and the acetic acid bacteria Acetobacter pasteurianus and Gluconobacter frateurii were the major species found in control fermentations. In fermentations with the presence of nisin and lysozyme, the same species of yeasts and acetic acid bacteria grew but the growth of lactic acid bacteria was prevented or restricted. These beans underwent characteristic alcoholic fermentation where the utilization of sugars and the production of ethanol, organic acids and volatile compounds in the bean pulp and nibs were similar for beans fermented in the presence of lactic acid bacteria. Lactic acid was produced during both fermentations but more so when lactic acid bacteria grew. Beans fermented in the presence or absence of lactic acid bacteria were fully fermented, had similar shell weights and gave acceptable chocolates with no differences

  18. Identification of Lactic Acid Bacteria and Propionic Acid Bacteria using FTIR Spectroscopy and Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Beata Nalepa

    2012-01-01

    Full Text Available In the present study, lactic acid bacteria and propionic acid bacteria have been identified at the genus level with the use of artificial neural networks (ANNs and Fourier transform infrared spectroscopy (FTIR. Bacterial strains of the genera Lactobacillus, Lactococcus, Leuconostoc, Streptococcus and Propionibacterium were analyzed since they deliver health benefits and are routinely used in the food processing industry. The correctness of bacterial identification by ANNs and FTIR was evaluated at two stages. At first stage, ANNs were tested based on the spectra of 66 reference bacterial strains. At second stage, the evaluation involved 286 spectra of bacterial strains isolated from food products, deposited in our laboratory collection, and identified by genus-specific PCR. ANNs were developed based on the spectra and their first derivatives. The most satisfactory results were reported for the probabilistic neural network, which was built using a combination of W5W4W3 spectral ranges. This network correctly identified the genus of 95 % of the lactic acid bacteria and propionic acid bacteria strains analyzed.

  19. 9th International Symposium on Lactic Acid Bacteria

    OpenAIRE

    Kuipers, Oscar P.; Poolman, Berend; Hugenholtz, Jeroen

    2008-01-01

    What’s new in the field of lactic acid bacteria? The 9th International Symposium on Lactic Acid Bacteria (LAB9) will take place 31 August to 4 September 2008 in Egmond aan Zee, The Netherlands. Traditionally, the triannual LAB symposium focuses on the themes of genetics, physiology, and applications of lactic acid bacteria (LAB). These microorganisms are widely used in the food industry but are also increasingly applied as probiotics, enzyme and metabolite factories, and vaccine delivery vehi...

  20. Antimutagenicity of fermented milk with lactic acid bacteria

    OpenAIRE

    細野, 明義; Akiyoshi, Hosono; 信州大学大学院農学研究科; Graduate School of Agriculture, Shinshu University

    2002-01-01

    Fermented milk and lactic acid bacteria have been considered to provide potential health benefits to human beings. Milk containing casein has been shown to be highly antimutagenic, and fermentation by lactic acid bacteria produces various hydrolytic peptides which contribute to the high antimutagenicity of fermented milk. The antimutagenic property of fermented milk was dependent on the strains of lactic acid bacteria and the fermentation time. Not only the proteolytic products of casein, but...

  1. Acetic Acid Bacteria as Symbionts of Insects

    KAUST Repository

    Crotti, Elena

    2016-06-14

    Acetic acid bacteria (AAB) are being increasingly described as associating with different insect species that rely on sugar-based diets. AAB have been found in several insect orders, among them Diptera, Hemiptera, and Hymenoptera, including several vectors of plant, animal, and human diseases. AAB have been shown to associate with the epithelia of different organs of the host, they are able to move within the insect’s body and to be transmitted horizontally and vertically. Here, we review the ecology of AAB and examine their relationships with different insect models including mosquitoes, leafhoppers, and honey bees. We also discuss the potential use of AAB in symbiont-based control strategies, such as “Trojan-horse” agents, to block the transmission of vector-borne diseases.

  2. [Regulating acid stress resistance of lactic acid bacteria--a review].

    Science.gov (United States)

    Wu, Chongde; Huang, Jun; Zhou, Rongqing

    2014-07-04

    As cell factories, lactic acid bacteria are widely used in food, agriculture, pharmaceutical and other industries. Acid stress is one the important survival challenges encountered by lactic acid bacteria both in fermentation process and in the gastrointestinal tract. Recently, the development of systems biology and metabolic engineering brings unprecedented opportunity for further elucidating the acid tolerance mechanisms and improving the acid stress resistance of lactic acid bacteria. This review addresses physiological mechanisms of lactic acid bacteria during acid stress. Moreover, strategies to improve the acid stress resistance of lactic acid were proposed.

  3. Identification of subdominant lactic acid bacteria in dawadawa (a ...

    African Journals Online (AJOL)

    ) by lactic acid bacteria (LAB) was investigated for seven days. The LAB isolated were Pediococcus pentosaceus, Lactobacillus raffinolactus, Leuconostoc mesenteroides, Leuconostoc sp, Pediococcus halophilus, Pediococcus sp ...

  4. Selectivity of Inhibition of N-Succinyl- l , l -Diaminopimelic Acid Desuccinylase in Bacteria: The product of dapE-gene Is Not the Target of l -Captopril Antimicrobial Activity

    OpenAIRE

    Uda, Narasimha Rao; Creus, Marc

    2011-01-01

    The emergence of bacterial strains that are resistant to virtually all currently available antibiotics underscores the importance of developing new antimicrobial compounds. N-succinyl-l,l-diaminopimelic acid desuccinylase (DapE) is a metallohydrolase involved in the meso-diaminopimelate (mDAP)/lysine biosynthetic pathway necessary for lysine biosynthesis and for building the peptidoglycan cell wall. Because DapE is essential for Gram-negative and some Gram-positive bacteria, DapE has been pro...

  5. Stress Physiology of Lactic Acid Bacteria.

    Science.gov (United States)

    Papadimitriou, Konstantinos; Alegría, Ángel; Bron, Peter A; de Angelis, Maria; Gobbetti, Marco; Kleerebezem, Michiel; Lemos, José A; Linares, Daniel M; Ross, Paul; Stanton, Catherine; Turroni, Francesca; van Sinderen, Douwe; Varmanen, Pekka; Ventura, Marco; Zúñiga, Manuel; Tsakalidou, Effie; Kok, Jan

    2016-09-01

    Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diverse as starter (e.g., Lactococcus lactis), probiotic (e.g., several Lactobacillus spp.), and pathogenic (e.g., Enterococcus and Streptococcus spp.) LAB. Here we present the state of the art for LAB stress behavior. We describe the multitude of stresses that LAB are confronted with, and we present the experimental context used to study the stress responses of LAB, focusing on adaptation, habituation, and cross-protection as well as on self-induced multistress resistance in stationary phase, biofilms, and dormancy. We also consider stress responses at the population and single-cell levels. Subsequently, we concentrate on the stress defense mechanisms that have been reported to date, grouping them according to their direct participation in preserving cell energy, defending macromolecules, and protecting the cell envelope. Stress-induced responses of probiotic LAB and commensal/pathogenic LAB are highlighted separately due to the complexity of the peculiar multistress conditions to which these bacteria are subjected in their hosts. Induction of prophages under environmental stresses is then discussed. Finally, we present systems-based strategies to characterize the "stressome" of LAB and to engineer new food-related and probiotic LAB with improved stress tolerance. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  6. Stress Physiology of Lactic Acid Bacteria

    Science.gov (United States)

    Papadimitriou, Konstantinos; Alegría, Ángel; Bron, Peter A.; de Angelis, Maria; Gobbetti, Marco; Kleerebezem, Michiel; Lemos, José A.; Linares, Daniel M.; Ross, Paul; Stanton, Catherine; Turroni, Francesca; van Sinderen, Douwe; Varmanen, Pekka; Ventura, Marco; Zúñiga, Manuel; Tsakalidou, Effie

    2016-01-01

    SUMMARY Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diverse as starter (e.g., Lactococcus lactis), probiotic (e.g., several Lactobacillus spp.), and pathogenic (e.g., Enterococcus and Streptococcus spp.) LAB. Here we present the state of the art for LAB stress behavior. We describe the multitude of stresses that LAB are confronted with, and we present the experimental context used to study the stress responses of LAB, focusing on adaptation, habituation, and cross-protection as well as on self-induced multistress resistance in stationary phase, biofilms, and dormancy. We also consider stress responses at the population and single-cell levels. Subsequently, we concentrate on the stress defense mechanisms that have been reported to date, grouping them according to their direct participation in preserving cell energy, defending macromolecules, and protecting the cell envelope. Stress-induced responses of probiotic LAB and commensal/pathogenic LAB are highlighted separately due to the complexity of the peculiar multistress conditions to which these bacteria are subjected in their hosts. Induction of prophages under environmental stresses is then discussed. Finally, we present systems-based strategies to characterize the “stressome” of LAB and to engineer new food-related and probiotic LAB with improved stress tolerance. PMID:27466284

  7. Characterization of lactic acid bacteria from local cow´s milk kefir

    Science.gov (United States)

    Ismail, YS; Yulvizar, C.; Mazhitov, B.

    2018-03-01

    One of products from milk fermentation is kefir. It is made by adding kefir grains which are composed of lactic acid bacteria and yeast into milk. The lactic acid bacteria are a group of bacteria that produce antimicrobial substances and able to inhibit the growth of pathogenic bacteria. In this research, the lactic acid bacteria were isolated from Aceh local cow`s milk kefir to determine the genus of the isolates. The methods used in the characterization of lactic acid bacteria are colony morphology, cell morphology, and biochemical tests which includes a catalase test; 5%, 6.5%, and 10% salt endurance tests; 37°C and 14°C temperature endurance tests, SIM test, TSIA test, MR-VP test, and O/F test. Of the four isolates found from the cow’s milk kefir, two isolates were confirmed as lactic acid bacteria (isolates SK-1 and SK-4). Both isolates are Gram positive bacteria, and have negative catalase activity. From the observations of colony morphology, cell morphology, and biochemical tests, it was found that the genus of SK-1 is Lactobacillus and the genus of SK-4 is Enterococcus.

  8. Introduction and comparison of measurement methods of antifungal properties of lactic acid bacteria in cheese

    Directory of Open Access Journals (Sweden)

    H Sedaghat

    2014-02-01

    Full Text Available Various laboratory methods have been developed to evaluate the effectiveness of anti-mould effect of lactic acid bacteria. However, most of these investigations have been conducted in culture medium. Due to the occurrence of complex interaction between food components and antimicrobial substances produced by lactic acid bacteria, the result achieved from these studies may be different from those seen in food model. In various studies growth inhibition of molds on the surface of foods are considered as antifungal activity. Consequently, introduction and comparison of efficient methods for evaluation of anti-mould effect of lactic acid bacteria would be helpful. In this study, antifungal activity of lactic acid bacteria inoculated in cheese was estimated using Microdilution method. Pieces of cheese samples were overlaid with molds and the antifungal effect of this bacteria was studied against Aspergillus flavus and Aspergillus parasiticus. All three methods showed the effectiveness of lactic bacteria on mold inhibition. Comparison of the results showed that there was significant positive correlation between antifungal overlay assay and direct growth of mold on cheese, since this two test showed antifungal effect in the same way including interaction between bacteria and mold and also producing antifungal compound.

  9. Molecular screening of wine lactic acid bacteria degrading hydroxycinnamic acids.

    Science.gov (United States)

    de las Rivas, Blanca; Rodríguez, Héctor; Curiel, José Antonio; Landete, José María; Muñoz, Rosario

    2009-01-28

    The potential to produce volatile phenols from hydroxycinnamic acids was investigated for lactic acid bacteria (LAB) isolated from Spanish grape must and wine. A PCR assay was developed for the detection of LAB that potentially produce volatile phenols. Synthetic degenerate oligonucleotides for the specific detection of the pdc gene encoding a phenolic acid decarboxylase were designed. The pdc PCR assay amplifies a 321 bp DNA fragment from phenolic acid decarboxylase. The pdc PCR method was applied to 85 strains belonging to the 6 main wine LAB species. Lactobacillus plantarum, Lactobacillus brevis, and Pediococcus pentosaceus strains produce a positive response in the pdc PCR assay, whereas Oenococcus oeni, Lactobacillus hilgardii, and Leuconostoc mesenteroides strains did not produce the expected PCR product. The production of vinyl and ethyl derivatives from hydroxycinnamic acids in culture media was determined by high-performance liquid chromatography. A relationship was found between pdc PCR amplification and volatile phenol production, so that the LAB strains that gave a positive pdc PCR response produce volatile phenols, whereas strains that did not produce a PCR amplicon did not produce volatile phenols. The proposed method could be useful for a preliminary identification of LAB strains able to produce volatile phenols in wine.

  10. Bacteriocins from lactic acid bacteria as an alternative to antibiotics.

    Science.gov (United States)

    Ołdak, Aleksandra; Zielińska, Dorota

    2017-05-05

    Bacteriocins are ribosomally synthesized, proteinaceous substances that inhibit the growth of closely related species through numerous mechanisms. The classification system used in this review divided bacteriocins into four sub-groups based on their size. Currently, there is extensive research focused on bacteriocins and their usage as a food preservative. The increasing incidence of multidrug resistant bacterial pathogens is one of the most pressing medical problems in recent years. Recently, the potential clinical application of LAB (Lactic Acid Bacteria) bacteriocin has been the subject of investigations by many scientists. Bacteriocins can be considered in a sense as antibiotic, although they differ from conventional antibiotics in numerous aspects. The gene-encoded nature of bacteriocins makes them easily amenable through bioengineering to either increase their activity or specify target microorganism. Owing to this feature of bacteriocins, antibiotic therapy would become less damaging to the natural gut microflora, which is a common drawback of conventional antibiotic use. Bacteriocins from lactic acid bacteria represent one of the most studied microbial defense systems and the idea of subjecting them to bioengineering to either increase antimicrobial activity or further specify their target microorganism is now a rapidly expanding field. This review aimed to present bacteriocins as a possible alternative to conventional antibiotics basic on latest scientific data.

  11. Probiotic properties of endemic strains of lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Flora N. Tkhruni

    2013-01-01

    Full Text Available Strains of lactic acid bacteria (LAB isolated from various samples of matsun, yogurt and salted cheese from natural farms of Armenia were studied. They have high antimicrobial and probiotic activities, growth rate and differ by their resistance to enzymes. Supernatants of LAB retain bactericidal activity at рН 3.0-8.0 and inhibit growth of various microflora. The application of different methods of identification and LAB genotyping (API 50 CH, 16S rRNA sequencing, GS-PCR, RAPD PCR showed that isolated LAB evidenced a 99.9% similarity with L. rhamnosus, L. plantarum and L. pentosus species and coccoid forms of Streptococcus and Enterococcus species. It can be concluded, that some strains of lactic acid bacteria, isolated from dairy products from natural farms of Armenia, can be properly used for biopreservation of some foodstuffs. On the basis of experimental data, the LAB can be used as basis for obtaining the new products of functional nutrition.

  12. Bacteriocins from lactic acid bacteria as an alternative to antibiotics

    Directory of Open Access Journals (Sweden)

    Aleksandra Ołdak

    2017-05-01

    Full Text Available Bacteriocins are ribosomally synthesized, proteinaceous substances that inhibit the growth of closely related species through numerous mechanisms. The classification system used in this review divided bacteriocins into four sub-groups based on their size. Currently, there is extensive research focused on bacteriocins and their usage as a food preservative.The increasing incidence of multidrug resistant bacterial pathogens is one of the most pressing medical problems in recent years. Recently, the potential clinical application of LAB (Lactic Acid Bacteria bacteriocin has been the subject of investigations by many scientists.Bacteriocins can be considered in a sense as antibiotic, although they differ from conventional antibiotics in numerous aspects. The gene-encoded nature of bacteriocins makes them easily amenable through bioengineering to either increase their activity or specify target microorganism. Owing to this feature of bacteriocins, antibiotic therapy would become less damaging to the natural gut microflora, which is a common drawback of conventional antibiotic use. Bacteriocins from lactic acid bacteria represent one of the most studied microbial defense systems and the idea of subjecting them to bioengineering to either increase antimicrobial activity or further specify their target microorganism is now a rapidly expanding field. This review aimed to present bacteriocins as a possible alternative to conventional antibiotics basic on latest scientific data.

  13. Metabolite Profiles of Lactic Acid Bacteria in Grass Silage▿

    OpenAIRE

    Broberg, Anders; Jacobsson, Karin; Ström, Katrin; Schnürer, Johan

    2007-01-01

    The metabolite production of lactic acid bacteria (LAB) on silage was investigated. The aim was to compare the production of antifungal metabolites in silage with the production in liquid cultures previously studied in our laboratory. The following metabolites were found to be present at elevated concentrations in silos inoculated with LAB strains: 3-hydroxydecanoic acid, 2-hydroxy-4-methylpentanoic acid, benzoic acid, catechol, hydrocinnamic acid, salicylic acid, 3-phenyllactic acid, 4-hydro...

  14. Antagonistic activity of isolated lactic acid bacteria from Pliek U against gram-negative bacteria Escherichia coli ATCC 25922

    Science.gov (United States)

    Kiti, A. A.; Jamilah, I.; Rusmarilin, H.

    2017-09-01

    Lactic acid bacteria (LAB) is one group of microbes that has many benefits, notably in food and health industries sector. LAB plays an important role in food fermentation and it has bacteriostatic effect against the growth of pathogenic microorganisms. The research related LAB continued to be done to increase the diversity of potential isolates derived from nature which is indigenous bacteria for biotechnological purposes. This study was aimed to isolate and characterize LAB derived from pliek u sample and to examine the potency to inhibits Escherichia coli ATCC 25922 bacteria growth. A total of 5 isolates were isolated and based on morphological and physiological characteristics of the fifth bacteria, they are allegedly belonging to the genus Bacillus. Result of antagonistic test showed that the five isolates could inhibits the growth of E. coli ATCC 25922. The highest inhibition zone is 8.5 mm was shown by isolates NQ2, while the lowest inhibition is 1.5 mm was shown by isolates NQ3.

  15. Influence of carbohydrates on the isolation of lactic acid bacteria.

    Science.gov (United States)

    Endo, A; Futagawa-Endo, Y; Dicks, L M T

    2011-04-01

      To determine the influence of carbohydrates on enrichment isolation of lactic acid bacteria from different niches.   Lactic acid bacteria in three traditional fermented products in southern Africa (amasi, mahewu and tshwala) and in three fresh samples (two flowers and a fruit) were enrichment cultured in media supplemented with 13 different carbohydrates. Diversity of lactic acid bacteria was determined by PCR-denaturing-gradient gel electrophoresis. Carbohydrates used in enrichment media had a big impact on the isolation of lactic acid bacteria from fermented products. Depending on the carbohydrates tested, the number of species detected ranged from one to four in amasi, one to five in mahewu and one to three in tshwala. Fructose and mannitol selected for relatively higher numbers of lactic acid bacteria in fermented products. Specific relationships between substrates and lactic acid bacteria have been noted. On the other hand, small influences were found among carbohydrates tested in flowers and fruit.   Carbohydrates have a big impact on the isolation of a variety of lactic acid bacteria in fermented food.   This is the first study that reports the influence of carbohydrates on the enrichment of lactic acid bacteria. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

  16. Bacteriocins and lactic acid bacteria - a minireview | Savadogo ...

    African Journals Online (AJOL)

    Fermentation of various foods by lactic acid bacteria (LAB) is one of the oldest forms of biopreservation practised by mankind. Bacterial antagonism has been recognized for over a century but in recent years this phenomenon has received more scientific attention, particulary in the use of various strains of lactic acid bacteria.

  17. Screening and identification of lactic acid bacteria isolated from ...

    African Journals Online (AJOL)

    The lactic acid bacteria (LAB) isolated from sorghum (Sorghum bicolor. L.) silage were identified during different periods of evolution of sorghum silage in west Algeria. Morphological, physiological, biochemical and technological techniques were used to characterize lactic acid bacteria isolates. A total number of 27 ...

  18. Antimicrobial activity of autochthonous lactic acid bacteria isolated ...

    African Journals Online (AJOL)

    Twenty samples of traditional fermented milk “Raib” were collected in eastern Algeria from individual household. They were evaluated for the presence of autochthonous bacteriocin-producing lactic acid bacteria. From 13 of these samples 52 strains of lactic acid bacteria were isolated, and shown to exhibit inhibitory activity ...

  19. Time related total lactic acid bacteria population diversity and ...

    African Journals Online (AJOL)

    user

    2011-02-07

    Feb 7, 2011 ... type. Comparison of 16S rDNA sequences of pure culture isolates with those in Genbank database revealed that, the dominating lactic acid bacteria were L. plantarum and Pediococcus species. Key words: Lactic acid bacteria, communities' diversity, fortified weaning foods, polymerase chain reaction.

  20. Biopreservative activity of lactic acid bacteria on suya produced from ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-10-20

    Oct 20, 2008 ... fermentative microorganisms (Ogunbanwo et al., 2004). *Corresponding author. E-mail: sokanisaac@yahoo.co.uk. Lactic acid bacteria (LAB) have been employed in the preservation of food materials for many centuries. In the meat industry, lactic acid bacteria are widely used as starter cultures for sausage ...

  1. Antimicrobial activities of lactic acid bacteria isolated from akamu ...

    African Journals Online (AJOL)

    SAM

    2014-07-16

    Jul 16, 2014 ... Key words: Bacteriocins, lactic acid bacteria (LAB), target organisms, antimicrobial activity. INTRODUCTION. Lactic acid bacteria (LAB) play essential roles in the fermentative production of many traditional foods. A wide variety of strains are routinely used as starter cultures in the manufacture of fermented ...

  2. Characterization of lactic acid bacteria from camel milk and their ...

    African Journals Online (AJOL)

    Proper selection and balance for starter culture is critical for the manufacture of fermented products of desirable texture and flavor. The objective of this study was to characterize lactic acid bacteria (LAB) from camel milk and elucidate their properties to use as a starter culture. Twenty-one lactic acid bacteria species were ...

  3. Compatible solutes in lactic acid bacteria subjected to water stress

    NARCIS (Netherlands)

    Kets, E.P.W.

    1997-01-01

    The goal of the research project described in this thesis was to investigate the protective effect of compatible solutes on tactic acid bacteria subjected to drying. Dried preparations of lactic acid bacteria are applied as starter cultures in feed and food industries. Dried starter

  4. Lactic Acid Bacteria : embarking on 30 more years of research

    NARCIS (Netherlands)

    Kok, Jan; Johansen, Eric; Kleerebezem, Michiel; Teusink, Bas

    2014-01-01

    The 11th International Symposium on Lactic Acid Bacteria Lactic Acid Bacteria play important roles in the pro- duction of food and feed and are increasingly used as health-promoting probiotics. The incessant scientific interest in these microorganisms by academic research groups as well as by

  5. Bacteriocins of lactic acid bacteria : extending the family

    NARCIS (Netherlands)

    Alvarez-Sieiro, Patricia; Montalbán-López, Manuel; Mu, Dongdong; Kuipers, Oscar P

    2016-01-01

    Lactic acid bacteria (LAB) constitute a heterogeneous group of microorganisms that produce lactic acid as the major product during the fermentation process. LAB are Gram-positive bacteria with great biotechnological potential in the food industry. They can produce bacteriocins, which are

  6. Bacteriocins produced by lactic acid bacteria: A review

    Directory of Open Access Journals (Sweden)

    Vesković-Moračanin Slavica M.

    2014-01-01

    Full Text Available Lactic acid bacteria (LAB have an essential role in the production of fermented products. With their metabolic activity, they influence the ripening processes - leading to desired sensory qualities while at the same time inhibiting the growth of undesired microorganisms. Because of their dominant role during fermentation and because of a long tradition of utilization, Lhave been designated as “safe microbiota”. Biological protection of LAB, as a naturally present and/or selected and intentionally added microflora, is realized through the production of non-specific (lactic acid, acetic acid and other volatile organic acids, hydrogen peroxide, diacetyl, etc and specific metabolites, bacteriocins. Bacteriocins are extracellularly released proteins or peptides which possess certain antibacterial activity towards certain types of microorganisms, usually related to the producing bacteria. Today, bacteriocins represent a very interesting potential for their application in the food industry. Their application can reduce the use of synthetic preservatives and/or the intensity of thermal treatment during food production consumer’s need for safe, fresh and minimally-processed food. With the intention of realizing this potential to the fullest, it is necessary to understand the nature of bacteriocins, their production mechanisms, regulations and actions, as well as the influence of external factors on the their antimicrobial activity. The composition of food, i.e. its characteristics (pH, temperature, ingredients and additives, types and quantities of epiphytic microbiota and the actual technological process used in production, can all influence the stability and activity of the added bacteriocins. The future research in this field should also aim to clarify this unknown aspect of the application of bacteriocins, to provide the necessary knowledge about the optimization of the external conditions and open up the possibility of discovering their new

  7. Antagonistic pattern of lactic acid bacteria against native spoilage ...

    African Journals Online (AJOL)

    CIBA

    2012-11-08

    borne bacteria. All three LABs exhibited inhibition ... enhance its keeping quality may have undesirable effects to consumers. Antibacterial ... dilutions, onto Baird parker agar (BPA, Hi- media, Mumbai) supplemented with sterile ...

  8. Pediocin production by recombinant lactic acid bacteria.

    Science.gov (United States)

    Somkuti, G A; Steinberg, D H

    2003-03-01

    Production of the anti-listerial bacteriocin, pediocin, by lactic acid bacteria (LAB) transformed with the cloning vector pPC418 (Ped+, 9.1 kb) was influenced by composition of media and incubation temperature. Maximum pediocin production, tested against Listeria innocua, by electrotransformants of Lactococcus lactis ssp. lactis was measured in tryptone/lactose/yeast extract medium after 24 h growth at 30 degrees C, while incubation at 40 degrees C was optimum for Ped+ transformants of Streptococcus thermophilus and Enterococcus faecalis. The amount of pediocin produced by S. thermophilus in skim milk and cheese whey supplemented with 0.5% yeast extract was estimated as 51,000 units ml(-1) and 25,000 units ml(-1), respectively. Pediocin production remained essentially unchanged in reconstituted skim milk or whey media diluted up to 10-fold. The results demonstrate the capacity of recombinant strains of LAB to produce pediocin in a variety of growth media including skim milk and inexpensive cheese whey-based media, requiring minimum nutritional supplementation.

  9. Zinc Binding by Lactic Acid Bacteria

    Directory of Open Access Journals (Sweden)

    Jasna Mrvčić

    2009-01-01

    Full Text Available Zinc is an essential trace element in all organisms. A common method for the prevention of zinc deficiency is pharmacological supplementation, especially in a highly available form of a metalloprotein complex. The potential of different microbes to bind essential and toxic heavy metals has recently been recognized. In this work, biosorption of zinc by lactic acid bacteria (LAB has been investigated. Specific LAB were assessed for their ability to bind zinc from a water solution. Significant amount of zinc ions was bound, and this binding was found to be LAB species-specific. Differences among the species in binding performance at a concentration range between 10–90 mg/L were evaluated with Langmuir model for biosorption. Binding of zinc was a fast process, strongly influenced by ionic strength, pH, biomass concentration, and temperature. The most effective metal-binding LAB species was Leuconostoc mesenteroides (27.10 mg of Zn2+ per gram of dry mass bound at pH=5 and 32 °C, during 24 h. FT-IR spectroscopy analysis and electron microscopy demonstrated that passive adsorption and active uptake of the zinc ions were involved.

  10. Nickel Inhibits Mitochondrial Fatty Acid Oxidation

    Science.gov (United States)

    Uppala, Radha; McKinney, Richard W.; Brant, Kelly A.; Fabisiak, James P.; Goetzman, Eric S.

    2015-01-01

    Nickel exposure is associated with changes in cellular energy metabolism which may contribute to its carcinogenic properties. Here, we demonstrate that nickel strongly represses mitochondrial fatty acid oxidation—the pathway by which fatty acids are catabolized for energy—in both primary human lung fibroblasts and mouse embryonic fibroblasts. At the concentrations used, nickel suppresses fatty acid oxidation without globally suppressing mitochondrial function as evidenced by increased glucose oxidation to CO2. Pre-treatment with L-carnitine, previously shown to prevent nickel-induced mitochondrial dysfunction in neuroblastoma cells, did not prevent the inhibition of fatty acid oxidation. The effect of nickel on fatty acid oxidation occurred only with prolonged exposure (>5 hr), suggesting that direct inhibition of the active sites of metabolic enzymes is not the mechanism of action. Nickel is a known hypoxia-mimetic that activates hypoxia inducible factor-1α (HIF1α). Nickel-induced inhibition of fatty acid oxidation was blunted in HIF1α knockout fibroblasts, implicating HIF1α as one contributor to the mechanism. Additionally, nickel down-regulated the protein levels of the key fatty acid oxidation enzyme very long-chain acyl-CoA dehydrogenase (VLCAD) in a dose-dependent fashion. In conclusion, inhibition of fatty acid oxidation by nickel, concurrent with increased glucose metabolism, represents a form of metabolic reprogramming that may contribute to nickel-induced carcinogenesis. PMID:26051273

  11. Antimicrobial activity of preparations after combined cultivation of lactic acid bacteria and yeast strains.

    Science.gov (United States)

    Balabekyan, Ts R; Karapetyan, K J; Khachatryan, T V; Khachatryan, G E; Tatikyan, S Sh

    2018-03-30

    Use of antimicrobials in both human and animal populations over the past several decades has led to the emergence of multidrug-resistant bacteria populations that are resistant to many commercially available drugs. For example, acquired resistance to first-line antimicrobial agents increasingly complicates the management of extra-intestinal infections due to Escherichia coli, which are a major source of illness and death. The continued development of new classes of natural antimicrobial agents, possessing antibacterial activity, has become of increasing importance for medicine and veterinary. So, selection of lactic acid bacteria and yeast strains for their combined cultivation with the aim of increasing of the activity is topical. It was shown that during combined cultivation of the lactic acid bacteria with probiotic properties and yeast strains, antimicrobial activity depends on the genus and species to which the strain of lactic acid bacteria and yeast belongs. They inhibited the growth of multidrug-resistant bacteria with better efficiency. Increasing of the antimicrobial activity can be explained by the synergetic effect of products of cultures metabolism and by interaction between lactic acid bacteria cells with the cell wall of yeasts. Our data showed perspectives of combined cultivation of yeast and lactic acid bacteria for creation of a new class of antimicrobial preparations with high antibacterial activity and broad spectrum of action. Preparation can be recommended for treatment of animals. © 2018 Blackwell Verlag GmbH.

  12. Characterization of anti-listerial lactic acid bacteria isolated from Thai fermented fish products

    DEFF Research Database (Denmark)

    Østergaard, Anya; Embarek, Peter Karim Ben; Wedell-Neergaard, C.

    1998-01-01

    further characterized and 43 strains were inhibitory against Listeria monocytogenes. The strains were inhibitory to other Gram- positive (lactic acid) bacteria probably because of production of bacteriocins. All 44 strains inhibited both Vibrio cholerae and Vibrio parahaemolyticus and 37 were inhibitory...

  13. COMPARISON OF OCCURENCE LACTIC ACID BACTERIA IN CHOSEN YOGURTS

    Directory of Open Access Journals (Sweden)

    Silvia Pinterová

    2010-11-01

    Full Text Available The yogurt is healthy food, which contains at least 100 million cultures per gram. Probiotic bacteria have been proven to reduce the effects of some gastrointestinal problems, probiotics can greatly reduce lactose intolerance, have also been proven to prevent colon cancers, there are also a natural immune system booster. In our research we detected numbers of lactid acid bacteria in yogurts in slovak market. There were classical yogurts, yogurts with probiotics, yogurts with fat and non fat. We numbered lactid acid bacteria from and after expiration, in agars MRS and Lee´s. In examined yogurts we detected from expiration from 78.107  to 169.107  and after expiration from 59.107 to 133.107 lactic acid bacteria in 1 ml of yogurt. In agreement with Food Codex of SR (2010 of rules all these yogurts satisfy number of lactid acid bacteria. doi:10.5219/31

  14. Lactic Acid Bacteria Differentially Activate Natural Killer Cells

    DEFF Research Database (Denmark)

    Fink, Lisbeth Nielsen; Christensen, Hanne Risager; Frøkiær, Hanne

    antigen presenting cells and T-cells. Bacteria translocating across the gastrointestinal mucosa are presumed to gain access to NK cell compartments, as consumption of certain strains of lactic acid bacteria has been shown to increase in vivo NK cytotoxic activity. On-going research in our lab aims...... at describing strain-dependent effects of lactic acid bacteria on regulatory functions of NK-cells. Here, we have investigated how human gut flora-derived non-pathogenic lactic acid bacteria affect NK cells in vitro, by measuring proliferation and IFN-gamma production of human peripheral blood NK cells upon...... bacterial stimulation. Methods: CD3-CD56+ NK cells were isolated from buffy coats by negative isolation using a lineage specific antibody cocktail and magnetic beads binding the labelling antibodies on non-NK cells. NK cells were incubated either with 10 microg/ml UV-inactivated lactic acid bacteria or 10...

  15. Lactic Acid Bacteria Producing Inhibitor of Alpha Glucosidase Isolated from Ganyong (Canna Edulis) and Kimpul (Xanthosoma sagittifolium)

    Science.gov (United States)

    Nurhayati, Rifa; Miftakhussolikhah; Frediansyah, Andri; Lailatul Rachmah, Desy

    2017-12-01

    Type 2 diabetes is a disease that caused by the failure of insulin secretion by the beta cells of the pancreas and insulin resistance in peripheral levels. One therapy for diabetics is by inhibiting the activity of α-glucosidase. Lactic acid bacteria have the ability to inhibit of α-glucosidase activity. The aims of this research was to isolation and screening of lactic acid bacteria from ganyong tuber (Canna Edulis) and kimpul tuber (Xanthosoma sagittifolium), which has the ability to inhibit the activity of α-glucosidase. Eightteen isolates were identified as lactic acid bacteria and all of them could inhibit the activity of α-glukosidase. The GN 8 isolate was perform the highest inhibition acivity.

  16. Importance of lactic acid bacteria in Asian fermented foods.

    Science.gov (United States)

    Rhee, Sook Jong; Lee, Jang-Eun; Lee, Cherl-Ho

    2011-08-30

    Lactic acid bacteria play important roles in various fermented foods in Asia. Besides being the main component in kimchi and other fermented foods, they are used to preserve edible food materials through fermentation of other raw-materials such as rice wine/beer, rice cakes, and fish by producing organic acids to control putrefactive microorganisms and pathogens. These bacteria also provide a selective environment favoring fermentative microorganisms and produce desirable flavors in various fermented foods. This paper discusses the role of lactic acid bacteria in various non-dairy fermented food products in Asia and their nutritional and physiological functions in the Asian diet.

  17. Characterization of lactic acid bacteria isolated from Algerian arid ...

    African Journals Online (AJOL)

    Diversity and density of lactic acid bacteria isolated from Algerian raw goats\\' milk in arid zones were studied by determination of morphological, cultural, physiological and biochemical characteristics. 206 lactic acid bacterial strains were isolated, with 115 of them belonging to lactic acid cocci and others to the genus, ...

  18. Genetics of the proteolytic system of lactic acid bacteria

    NARCIS (Netherlands)

    Kok, Jan

    1990-01-01

    The proteolytic system of lactic acid bacteria is of eminent importance for the rapid growth of these organisms in protein-rich media. The combined action of proteinases and peptidases provides the cell with small peptides and essential amino acids. The amino acids and peptides thus liberated have

  19. Interaction of neptunium with humic acid and anaerobic bacteria

    International Nuclear Information System (INIS)

    Kubota, Takumi; Sasaki, Takayuki; Kudo, Akira

    2002-01-01

    Humic acid and bacteria play an important role in the migration of radionuclides in groundwaters. The interaction of neptunium with humic acid and anaerobic bacteria has been investigated by liquid/liquid and solid/liquid extraction systems. For liquid/liquid extraction, the apparent complex formation constant, β α was obtained from the distribution between two phases of neptunium. For solid/liquid extraction, the ratio of sorption to bacteria, K d , was measured. K d of humic acid can be evaluated from β α . The large value of β α and K d means strong interaction of neptunium with organisms. In order to examine the effect of the nature of organism on interaction, the interaction with humic acid was compared to that with non-sterilized or sterilized mixed anaerobic bacteria. The value of β α of humate depended on neptunium ion concentration as well as pH, which showed the effect of polyelectrolyte properties and heterogeneous composition of humic acid. The comparison of interaction with humic acid and bacteria indicated that the K d value of humic acid was larger than that of bacteria and more strongly depend on pH. (author)

  20. Isolation of lactic acid bacteria with potential protective culture characteristics from fruits

    Science.gov (United States)

    Hashim, Nurul Huda; Sani, Norrakiah Abdullah

    2015-09-01

    Lactic acid bacteria are also known as beneficial microorganisms abundantly found in fermented food products. In this study, lactic acid bacteria were isolated from fresh cut fruits obtained from local markets. Throughout the isolation process from 11 samples of fruits, 225 presumptive lactic acid bacteria were isolated on MRS agar medium. After catalase and oxidase tests, 149 resulted to fit the characteristics of lactic acid bacteria. Further identification using Gram staining was conducted to identify the Gram positive bacteria. After this confirmation, the fermentation characteristics of these isolates were identified. It was found that 87 (58.4%) isolates were heterofermentative, while the rest of 62 (41.6%) are homofermentative lactic acid bacteria. Later, all these isolates were investigated for the ability to inhibit growth of Staphylococcus aureus using agar spot assay method. Seven (4.7%) isolates showed strong antagonistic capacity, while 127 (85.2%) and 8 (5.4%) isolates have medium and weak antagonistic capacity, respectively. The other 7 (4.7%) isolates indicated to have no antagonistic effect on S. aureus. Results support the potential of LAB isolated in this study which showed strong antagonistic activity against S. aureus may be manipulated to become protective cultures in food products. While the homofermentative or heterofermentative LAB can be utilized in fermentation of food and non-food products depending on the by-products required during the fermentation.

  1. Isolation And Characterization Of Lactic Acid Bacteria In Kirario, An ...

    African Journals Online (AJOL)

    The lactic acid bacteria (LAB) are the most diverse groups of bacteria known, and have been used by many communities in the World in spontaneous fermentation to produce fermented porridges with unique technological characteristics. Kirario is a traditional fermented porridge based on green maize, millet and/or ...

  2. Selection of local extremophile lactic acid bacteria with high capacity ...

    African Journals Online (AJOL)

    These bacteria can exist under extreme conditions of the digestive tract (acidity and high concentration of bile salts) and have a high capacity to degrade lactose. The aim is to produce yoguort with the bacteria that remain viable and active in the digestive tract, so as to enhance lactase activity at the intolerant lactose.

  3. Antibacterial Activities of Lactic Acid Bacteria Isolated from Selected ...

    African Journals Online (AJOL)

    Members of lactic acid bacteria (LAB) are known probiotics and have been reported to have antimicrobial properties. Although various researchers have documented the isolation of these bacteria from fruits and vegetables, studies on LAB associated with lettuce, cucumber and cabbage are limited and non-existing in ...

  4. Effects of supplementing lactic acid bacteria on fecal microbiota ...

    African Journals Online (AJOL)

    Results: The results indicated that Lactobacillus plantarum strain L.p X3-2B increased fecal lactic acid bacteria(LAB) and Bifidobacterium while resisting the growth of harmful bacteria. Viable counts of LAB and Bifidobacterium reached 8 log cfu/mL after feeding for 14 days. Fecal pH in the control group was high in ...

  5. Antibacterial Activity of Lactic Acid Bacteria Isolated from Healthy ...

    African Journals Online (AJOL)

    Lactic acid bacteria (LAB), namely, Lactobacillus acidophilus 1, Lactobacillus acidophilus 2, Lactobacillus brevis 1, Lactobacillus rhamnosus 1, Lactococcus lactis subsp. lactis 1, Lactococcus lactis subsp. lactis 2, Lactococcus raffinolactis 1, Pediococcus acidilactici 1, Pediococcus pentosaceus 1, and Pediococcus ...

  6. Efficacy of lactic acid bacteria in the reduction of trimethylamine ...

    African Journals Online (AJOL)

    Different strains of lactic acid bacteria (LAB) such as Pediococcus acidilactici, Pediococcus pentosaceous, Streptococcus thermophilus, Lactococcus lactis, Lactobacillus plantarum, Lactobacillus acidophilus and Lactobacillus helveticus were procured from the NCL (National Chemical Laboratory), Pune, India. These LAB ...

  7. Screening of malting sorghum samples for lactic acid bacteria with ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-17

    Jun 17, 2009 ... fermentum and Lactobacillus acidophilus, respectively. LAB isolated from three varieties of sorghum grains undergoing malting exhibited the ability to produce bacteriocin and hydrogen peroxide. Key words: Lactic acid bacteria, sorghum varieties, malting, bacteriocin, hydrogen peroxide. INTRODUCTION.

  8. Technologically important properties of lactic acid bacteria isolated ...

    African Journals Online (AJOL)

    SERVER

    2007-07-18

    Jul 18, 2007 ... facultatively heterofermentative lactobacilli. Lactic acid bacteria were identified on the basis of phenotypic characters as Lactococcus lactis subsp. lactis, Enterococcus faecalis, Enterococcus faecium, Enterococcus durans, Lactobacillus paracasei subsp. paracasei, Lactobacillus plantarum and.

  9. Characterization of lactic acid bacteria isolated from indigenous dahi ...

    African Journals Online (AJOL)

    Diversity and density of lactic acid bacteria from indigenous dahi were studied by the determination of morphological, cultural, physiological and biochemical characteristics. A total of 143 isolates were identified phenotypically and divided into three genera: Lactobacillus, Lactococcus and Streptococcus.

  10. Antibacterial Activity of Lactic Acid Bacteria Isolated from Salad ...

    African Journals Online (AJOL)

    To determine the inhibitory capacity of lactic acid bacteria (LAB) due to the action of antagonistic substances, 8 members of the LAB group namely, Lactobacillus brevis, Lactobacillus casei, Lactobacillus cellebiosuis, Lactobacillus delbruesckii, Lactobacillus fermentum, Lactobacillus plantarum, Leuconostoc mesenteroides ...

  11. Possible Probiotic Lactic Acid Bacteria Isolated from Oysters (Crassostrea gigas).

    Science.gov (United States)

    Kang, Chang-Ho; Gu, Takyong; So, Jae-Seong

    2017-09-05

    We attempted to isolate lactic acid bacteria (LAB) from the marine oyster (Crassostrea gigas) and selected several environmental stress-resistant isolates for the development of a future probiotic adjuvant for marine aquaculture. Twenty-six presumptive LAB isolates were extracted from oysters and screened (by an agar diffusion assay) for antimicrobial activity toward various pathogens: Vibrio parahaemolyticus, Streptococcus iniae, and Edwardsiella tarda. Eight isolates had an antibacterial activity toward V. parahaemolyticus; in particular, 6 isolates showed a growth-inhibitory activity, with inhibition zone diameters > 15 mm. Of these, 5 isolates (JL17, JL18, JL28, HL7, and HL32) were also active against S. iniae and E. tarda. Enterococcus faecium HL7 was selected as the isolate most resistant to environmental stressors: the minimum NaCl, ethanol, and hydrogen peroxide concentrations at which HL7 cells lost their viability were 1.9 M, 11%, and 0.013%, respectively. When an antibiotic sensitivity test was performed on E. faecium HL7, this isolate was found to be resistant to trimethoprim/sulfamethoxazole, cephalothin, ampicillin, rifampin, gentamicin, cefotaxime, cefepime, cefotetan, nalidixic acid, and kanamycin. While the oyster model studies provided indication that E. faecium HL7 could be a good candidate as biocontrol agent against V. vulnificus, further optimization is needed in the actual animal rearing situation.

  12. Probiotic lactic acid bacteria for applications in vegetarian food products

    Directory of Open Access Journals (Sweden)

    Charernjiratrakul, W.

    2007-07-01

    Full Text Available Total of 225 isolates of lactic acid bacteria were isolated from 152 samples of various fermented foods. The strains were investigated for their probiotic properties based on stability in bile salt (0.30% and high acidity (pH 3, growth under both aerobic and anaerobic conditions, ability to grow without vitamin B12. According to the above criteria, 40 isolates were selected. Using an agar spot method, 16 isolates were able to inhibit Salmonella typhimurium, S. typhi, S. enteritidis, S. paratyphi and 4 strains of E. coli O157 : H7 as clear zone greater than 10 mm. Moreover, utilization of protein or fat or starch was also considered. Only 5 isolates were able to utilize protein and further selected for antibiotics sensitivity test. The selected isolates were susceptible to following antibiotics: ampicillin, chloramphenicol, erythromycin , kanamycin, tetracycline and vancomycin; however they were resistant to ceptazidime and norfloxacin. They all showed better growth in vegetarian medium (coconut juice medium than MRS medium both under static and shaking conditions. Five active isolates were identified as Lactobacillus plantarum LL13, LN18, LP11, LS35 and Pediococcus pentosaceus LT02 by API 50 CH system. All cultures grew well in carrot juice by reducing pH from 6.4 to below 4.0 after 24 h of fermentation at 35oC. The lactic cultures in fermented carrot juice lost their viability about 2 log cycles after 15 days of cold storage at 4oC.

  13. Phytic Acid Inhibits Lipid Peroxidation In Vitro

    Directory of Open Access Journals (Sweden)

    Alicja Zajdel

    2013-01-01

    Full Text Available Phytic acid (PA has been recognized as a potent antioxidant and inhibitor of iron-catalyzed hydroxyl radical formation under in vitro and in vivo conditions. Therefore, the aim of the present study was to investigate, with the use of HPLC/MS/MS, whether PA is capable of inhibiting linoleic acid autoxidation and Fe(II/ascorbate-induced peroxidation, as well as Fe(II/ascorbate-induced lipid peroxidation in human colonic epithelial cells. PA at 100 μM and 500 μM effectively inhibited the decay of linoleic acid, both in the absence and presence of Fe(II/ascorbate. The observed inhibitory effect of PA on Fe(II/ascorbate-induced lipid peroxidation was lower (10–20% compared to that of autoxidation. PA did not change linoleic acid hydroperoxides concentration levels after 24 hours of Fe(II/ascorbate-induced peroxidation. In the absence of Fe(II/ascorbate, PA at 100 μM and 500 μM significantly suppressed decomposition of linoleic acid hydroperoxides. Moreover, PA at the tested nontoxic concentrations (100 μM and 500 μM significantly decreased 4-hydroxyalkenal levels in Caco-2 cells which structurally and functionally resemble the small intestinal epithelium. It is concluded that PA inhibits linoleic acid oxidation and reduces the formation of 4-hydroxyalkenals. Acting as an antioxidant it may help to prevent intestinal diseases induced by oxygen radicals and lipid peroxidation products.

  14. The impact of lactic acid bacteria on sourdough fermentation

    Directory of Open Access Journals (Sweden)

    Savić Dragiša S.

    2005-01-01

    Full Text Available The baking of sourdough breads represents one of the oldest biotechnological processes. Despite traditionality, sourdough bread has great potential because of its benefits. Sourdough is a mixture of flour and water that is dominated by a complex microflora composed of yeasts and lactic acid bacteria that are crucial in the preparation of bread dough. Lactic acid bacteria cause acidification by producing lactic acid that increases the shelf life of bread by preventing the growth of undesirable microorganisms and affects the nutritional value of bread by increasing the availability of minerals. In addition to these advantages, the use of sourdough fermentation also improves dough machinability, breadcrumb structure and the characteristic flavour of bread. Lactic acid bacteria in sourdough fermentation are well known representing both homofermentative and heterofermentative bacteria. They may originate from selected natural contaminants in the flour or from a starter culture containing one or more known species of lactic acid bacteria. Sourdough can be cultivated in bakeries or obtained from commercial suppliers. However, many bakeries in Europe still use spontaneously fermented sourdoughs, which have been kept metabolically active for decades by the addition of flour and water at regular intervals. The impact of lactic acid bacteria on sourdough fermentation and their influence on dough and bread quality was discussed on the basis of research and literature data.

  15. Undecylenic Acid Inhibits Morphogenesis of Candida albicans

    OpenAIRE

    McLain, Nealoo; Ascanio, Rhoda; Baker, Carol; Strohaver, Robert A.; Dolan, Joseph W.

    2000-01-01

    Resilient liners are frequently used to treat denture stomatitis, a condition often associated with Candida albicans infections. Of 10 liners tested, 2 were found to inhibit the switch from the yeast form to hyphae and a third was found to stimulate this switch. The inhibitor was determined to be undecylenic acid.

  16. Undecylenic acid inhibits morphogenesis of Candida albicans.

    Science.gov (United States)

    McLain, N; Ascanio, R; Baker, C; Strohaver, R A; Dolan, J W

    2000-10-01

    Resilient liners are frequently used to treat denture stomatitis, a condition often associated with Candida albicans infections. Of 10 liners tested, 2 were found to inhibit the switch from the yeast form to hyphae and a third was found to stimulate this switch. The inhibitor was determined to be undecylenic acid.

  17. Probiotic lactic acid bacteria ? the fledgling cuckoos of the gut?

    OpenAIRE

    Berstad, Arnold; Raa, Jan; Midtvedt, Tore; Valeur, J?rgen

    2016-01-01

    It is tempting to look at bacteria from our human egocentric point of view and label them as either ‘good’ or ‘bad’. However, a microbial society has its own system of government – ‘microcracy’ – and its own rules of play. Lactic acid bacteria are often referred to as representatives of the good ones, and there is little doubt that those belonging to the normal intestinal flora are beneficial for human health. But we should stop thinking of lactic acid bacteria as always being ‘friendly’ – th...

  18. Probiotic lactic acid bacteria - the fledgling cuckoos of the gut?

    Science.gov (United States)

    Berstad, Arnold; Raa, Jan; Midtvedt, Tore; Valeur, Jørgen

    2016-01-01

    It is tempting to look at bacteria from our human egocentric point of view and label them as either 'good' or 'bad'. However, a microbial society has its own system of government - 'microcracy' - and its own rules of play. Lactic acid bacteria are often referred to as representatives of the good ones, and there is little doubt that those belonging to the normal intestinal flora are beneficial for human health. But we should stop thinking of lactic acid bacteria as always being 'friendly' - they may instead behave like fledgling cuckoos.

  19. Genetics of the proteolytic system of lactic acid bacteria

    OpenAIRE

    Kok, Jan

    1990-01-01

    The proteolytic system of lactic acid bacteria is of eminent importance for the rapid growth of these organisms in protein-rich media. The combined action of proteinases and peptidases provides the cell with small peptides and essential amino acids. The amino acids and peptides thus liberated have to be translocated across the cytoplasmic membrane. To that purpose, the cell contains specific transport proteins. The internalized peptides are further degraded to amino acids by intracellullar pe...

  20. Hypolipidemic effects of lactic acid bacteria fermented cereal in rats

    Directory of Open Access Journals (Sweden)

    Banjoko Immaculata

    2012-12-01

    Full Text Available Abstract Background The objectives of the present study were to investigate the efficacy of the mixed culture of Lactobacillus acidophilus (DSM 20242, Bifidobacterium bifidum (DSM 20082 and Lactobacillus helveticus (CK60 in the fermentation of maize and the evaluation of the effect of the fermented meal on the lipid profile of rats. Methods Rats were randomly assigned to 3 groups and each group placed on a Diet A (high fat diet into which a maize meal fermented with a mixed culture of Lb acidophilus (DSM 20242, B bifidum (DSM 20082 and Lb helveticus (CK 60 was incorporated, B (unfermented high fat diet or C (commercial rat chow respectively after the first group of 7 rats randomly selected were sacrificed to obtain the baseline data. Thereafter 7 rats each from the experimental and control groups were sacrificed weekly for 4 weeks and the plasma, erythrocytes, lipoproteins and organs of the rats were assessed for cholesterol, triglyceride and phospholipids. Results Our results revealed that the mixed culture of Lb acidophilus (DSM 20242, B bifidum (DSM 20082 and Lb helveticus (CK 60 were able to grow and ferment maize meal into ‘ogi’ of acceptable flavour. In addition to plasma and hepatic hypercholesterolemia and hypertriglyceridemia, phospholipidosis in plasma, as well as cholesterogenesis, triglyceride constipation and phospholipidosis in extra-hepatic tissues characterized the consumption of unfermented hyperlipidemic diets. However, feeding the animals with the fermented maize diet reversed the dyslipidemia. Conclusion The findings of this study indicate that consumption of mixed culture lactic acid bacteria (Lb acidophilus (DSM 20242, Bifidobacterium bifidum (DSM 20082 and Lb helveticus (CK 60 fermented food results in the inhibition of fat absorption. It also inhibits the activity of HMG CoA reductase. This inhibition may be by feedback inhibition or repression of the transcription of the gene encoding the enzyme via activation of the

  1. Effects of humic acids on the growth of bacteria

    Science.gov (United States)

    Tikhonov, V. V.; Yakushev, A. V.; Zavgorodnyaya, Yu. A.; Byzov, B. A.; Demin, V. V.

    2010-03-01

    The influence of humic acids of different origins on the growth of bacterial cultures of different taxa isolated from the soil and the digestive tracts of earthworms ( Aporrectodea caliginosa)—habitats with contrasting conditions—was studied. More than half of the soil and intestinal isolates from the 170 tested strains grew on the humic acid of brown coal as the only carbon source. The specific growth rate of the bacteria isolated from the intestines of the earthworms was higher than that of the soil bacteria. The use of humic acids by intestinal bacteria confirms the possibility of symbiotic digestion by earthworms with the participation of bacterial symbionts. Humic acids at a concentration of 0.1 g/l stimulated the growth of the soil and intestinal bacteria strains (66 strains out of 161) on Czapek’s medium with glucose (1 g/l), probably, acting as a regulator of the cell metabolism. On the medium with the humic acid, the intestinal bacteria grew faster than the soil isolates did. The most active growth of the intestinal isolates was observed by Paenibacillus sp., Pseudomonas putida, Delftia acidovorans, Microbacterium terregens, and Aeromonas sp.; among the soil ones were the representatives of the Pseudomonas genus. A response of the bacteria to the influence of humic acids was shown at the strain level using the example of Pseudomonas representatives. The Flexom humin preparation stimulated the growth of the hydrocarbon-oxidizing Acinetobacter sp. bacteria. This effect can be used for creating a new compound with the elevated activity of bacteria that are destroyers of oil and oil products.

  2. Interactions among lactic acid starter and probiotic bacteria used for fermented dairy products.

    Science.gov (United States)

    Vinderola, C G; Mocchiutti, P; Reinheimer, J A

    2002-04-01

    Interactions among lactic acid starter and probiotic bacteria were investigated to establish adequate combinations of strains to manufacture probiotic dairy products. For this aim, a total of 48 strains of Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactococcus lactis, Lactobacillus acidophilus, Lactobacillus casei, and Bifidobacterium spp. (eight of each) were used. The detection of bacterial interactions was carried out using the well-diffusion agar assay, and the interactions found were further characterized by growth kinetics. A variety of interactions was demonstrated. Lb. delbrueckii subsp. bulgaricus was found to be able to inhibit S. thermophilus strains. Among probiotic cultures, Lb. acidophilus was the sole species that was inhibited by the others (Lb. casei and Bifidobacterium). In general, probiotic bacteria proved to be more inhibitory towards lactic acid bacteria than vice versa since the latter did not exert any effect on the growth of the former, with some exceptions. The study of interactions by growth kinetics allowed the setting of four different kinds of behaviors between species of lactic acid starter and probiotic bacteria (stimulation, delay, complete inhibition of growth, and no effects among them). The possible interactions among the strains selected to manufacture a probiotic fermented dairy product should be taken into account when choosing the best combination/s to optimize their performance in the process and their survival in the products during cold storage.

  3. The influence of stress conditions on the growth of selected lactic acid bacteria

    International Nuclear Information System (INIS)

    Bok, H.E.

    1985-01-01

    A study was undertaken to determine the effects of certain stress conditions on selected lactic acid bacteria. Where recontamination occurred, lactic acid bacteria was already the dominant bacterial group, with counts of higher than 10 6 /g in vacuum-packaged 'shelf stable' meat products after 1 week storage at 25 and 37 degrees Celsius respectively. Some of the isolates were capable of growing at a pH of 3,9. The minimum pH for growth of a specific culture was dependant on the type of acid that was used to lower the pH. Lactic and acetic acid had the highest inhibitory action. Hydrochloric and citric acid showed similar inhibitory effects, while the effects when using ascorbic acid or gluconic acid for lowering the pH were also fairly similar. Increase in the activity of certain lactic acid bacteria was noticed where the ratio of undissociated to dissociated citric acid in the medium was increased. After exceeding a concentration of 0,048 moles/l undissosiated citric acid in the medium, the activity of the majority of cultures was progressively inhibited. This phenomenon was also found with acetic acid for certain cultures. Selected lactic acid bacteria were resistant to an water activity (a (sub w)) of 0,94 in MRS broth, where NaCl or glycerol was used as a humectant. The minimum a (sub w) for growth was dependent on the type of humectant used. Concentrations of sodium benzoate and potassium sorbate were necessary to inhibit the majority of strains. The % inhibition by sodium benzoate and methyl paraben did not significantly change with a lowering in the pH of the growth medium. Except in the case of lactic acid, the different acids used to lower the pH of the medium did not have a significant effect on the % inhibition by the chemical preservatives. For the cocci, gamma D 10 values of between 0,82 and 1,29 kGy were recorded, whereas the lactobacilli were less resistant to gamma rays, with D 10 values of between 0,21 and 0,54 kGy

  4. Inhibitory effect of bacteriocin-producing lactic acid bacteria against histamine-forming bacteria isolated from Myeolchi-jeot

    Directory of Open Access Journals (Sweden)

    Eun-Seo Lim

    2016-12-01

    Full Text Available Abstract The objectives of this study were to identify the histamine-forming bacteria and bacteriocin- producing lactic acid bacteria (LAB isolated from Myeolchi-jeot according to sequence analysis of the 16S rRNA gene, to evaluate the inhibitory effects of the bacteriocin on the growth and histamine accumulation of histamine-forming bacteria, and to assess the physico-chemical properties of the bacteriocin. Based on 16S rRNA gene sequences, histamine-forming bacteria were identified as Bacillus licheniformis MCH01, Serratia marcescens MCH02, Staphylococcus xylosus MCH03, Aeromonas hydrophila MCH04, and Morganella morganii MCH05. The five LAB strains identified as Pediococcus acidilactici MCL11, Leuconostoc mesenteroides MCL12, Enterococcus faecium MCL13, Lactobacillus sakei MCL14, and Lactobacillus acidophilus MCL15 were found to produce an antibacterial compound with inhibitory activity against the tested histamine-producing bacteria. The inhibitory activity of these bacteriocins obtained from the five LAB remained stable after incubation at pH 4.0–8.0 and heating for 10 min at 80 °C; however, the bacteriocin activity was destroyed after treatment with papain, pepsin, proteinase K, α-chymotrypsin, or trypsin. Meanwhile, these bacteriocins produced by the tested LAB strains also exhibited histamine-degradation ability. Therefore, these antimicrobial substances may play a role in inhibiting histamine formation in the fermented fish products and preventing seafood-related food-borne disease caused by bacterially generated histamine.

  5. Remediation of Acid Mine Drainage with Sulfate Reducing Bacteria

    Science.gov (United States)

    Hauri, James F.; Schaider, Laurel A.

    2009-01-01

    Sulfate reducing bacteria have been shown to be effective at treating acid mine drainage through sulfide production and subsequent precipitation of metal sulfides. In this laboratory experiment for undergraduate environmental chemistry courses, students design and implement a set of bioreactors to remediate acid mine drainage and explain observed…

  6. Continuous Cultivation of Photosynthetic Bacteria for Fatty Acids Production

    DEFF Research Database (Denmark)

    Kim, Dong-Hoon; Lee, Ji-Hye; Hwang, Yuhoon

    2013-01-01

    In the present work, we introduced a novel approach for microbial fatty acids (FA) production. Photosynthetic bacteria, Rhodobacter sphaeroides KD131, were cultivated in a continuous-flow, stirred-tank reactor (CFSTR) at various substrate (lactate) concentrations.At hydraulic retention time (HRT)....... sphaeroides was around 35% of dry cell weight, mainly composed of vaccenic acid (C18:1, omega-7)....

  7. Engineering metabolic highways in Lactococci and other lactic acid bacteria

    NARCIS (Netherlands)

    Vos, de W.M.; Hugenholtz, J.

    2004-01-01

    Lactic acid bacteria (LAB) are widely used in industrial food fermentations and are receiving increased attention for use as cell factories for the production of food and pharmaceutical products. Glycolytic conversion of sugars into lactic acid is the main metabolic highway in these Gram-positive

  8. Making More of Milk Sugar by Engineering Lactic Acid Bacteria

    NARCIS (Netherlands)

    Vos, Willem M. de; Hols, Pascal; Kranenburg, Richard van; Luesink, Evert; Kuipers, Oscar P.; Oost, John van der; Kleerebezem, Michiel; Hugenholtz, Jeroen

    1998-01-01

    By exploiting their genetic and metabolic capacity, lactic acid bacteria can be used to generate a variety of products from milk sugar lactose other than the archetypical lactic acid. This review will outline the different genetic and metabolic engineering strategies that can be applied to lactic

  9. High efficiency recombineering in lactic acid bacteria

    OpenAIRE

    van Pijkeren, Jan-Peter; Britton, Robert A.

    2012-01-01

    The ability to efficiently generate targeted point mutations in the chromosome without the need for antibiotics, or other means of selection, is a powerful strategy for genome engineering. Although oligonucleotide-mediated recombineering (ssDNA recombineering) has been utilized in Escherichia coli for over a decade, the successful adaptation of ssDNA recombineering to Gram-positive bacteria has not been reported. Here we describe the development and application of ssDNA recombineering in lact...

  10. Structural diversity and biological significance of lipoteichoic acid in Gram-positive bacteria: focusing on beneficial probiotic lactic acid bacteria.

    Science.gov (United States)

    Shiraishi, Tsukasa; Yokota, Shinichi; Fukiya, Satoru; Yokota, Atsushi

    2016-01-01

    Bacterial cell surface molecules are at the forefront of host-bacterium interactions. Teichoic acids are observed only in Gram-positive bacteria, and they are one of the main cell surface components. Teichoic acids play important physiological roles and contribute to the bacterial interaction with their host. In particular, lipoteichoic acid (LTA) anchored to the cell membrane has attracted attention as a host immunomodulator. Chemical and biological characteristics of LTA from various bacteria have been described. However, most of the information concerns pathogenic bacteria, and information on beneficial bacteria, including probiotic lactic acid bacteria, is insufficient. LTA is structurally diverse. Strain-level structural diversity of LTA is suggested to underpin its immunomodulatory activities. Thus, the structural information on LTA in probiotics, in particular strain-associated diversity, is important for understanding its beneficial roles associated with the modulation of immune response. Continued accumulation of structural information is necessary to elucidate the detailed physiological roles and significance of LTA. In this review article, we summarize the current state of knowledge on LTA structure, in particular the structure of LTA from lactic acid bacteria. We also describe the significance of structural diversity and biological roles of LTA.

  11. Boswellic acid inhibits expression of acid sphingomyelinase in intestinal cells

    Directory of Open Access Journals (Sweden)

    Duan Rui-Dong

    2009-12-01

    Full Text Available Abstract Background Boswellic acid is a type of triterpenoids with antiinflammatory and antiproliferative properties. Sphingomyelin metabolism generates multiple lipid signals affecting cell proliferation, inflammation, and apoptosis. Upregulation of acid sphingomyelinase (SMase has been found in several inflammation-related diseases such as inflammatory bowel diseases, atherosclerosis, and diabetes. Methods The present study is to examine the effect of 3-acetyl-11-keto-β-boswellic acids (AKBA, a potent boswellic acid, on acid SMase activity and expression in intestinal cells. Both transformed Caco-2 cells and non-transformed Int407 cells were incubated with AKBA. After incubation, the change of acid SMase activity was assayed biochemically, the enzyme protein was examined by Western blot, and acid SMase mRNA was quantified by qPCR. Results We found that AKBA decreased acid SMase activity in both intestinal cell lines in dose and time dependent manners without affecting the secretion of the enzyme to the cell culture medium. The effect of AKBA was more effective in the fetal bovine serum-free culture medium. Among different types of boswellic acid, AKBA was the most potent one. The inhibitory effect on acid SMase activity occurred only in the intact cells but not in cell-free extract in the test tubes. At low concentration, AKBA only decreased the acid SMase activity but not the quantity of the enzyme protein. However, at high concentration, AKBA decreased both the mass of acid SMase protein and the mRNA levels of acid SMase in the cells, as demonstrated by Western blot and qPCR, respectively. Under the concentrations decreasing acid SMase activity, AKBA significantly inhibited cell proliferation. Conclusion We identified a novel inhibitory effect of boswellic acids on acid SMase expression, which may have implications in human diseases and health.

  12. Lactobacillus plantarum lipoteichoic acid inhibits biofilm formation of Streptococcus mutans

    Science.gov (United States)

    Ahn, Ki Bum; Baik, Jung Eun; Park, Ok-Jin; Yun, Cheol-Heui

    2018-01-01

    Dental caries is a biofilm-dependent oral disease and Streptococcus mutans is the known primary etiologic agent of dental caries that initiates biofilm formation on tooth surfaces. Although some Lactobacillus strains inhibit biofilm formation of oral pathogenic bacteria, the molecular mechanisms by which lactobacilli inhibit bacterial biofilm formation are not clearly understood. In this study, we demonstrated that Lactobacillus plantarum lipoteichoic acid (Lp.LTA) inhibited the biofilm formation of S. mutans on polystyrene plates, hydroxyapatite discs, and dentin slices without affecting the bacterial growth. Lp.LTA interferes with sucrose decomposition of S. mutans required for the production of exopolysaccharide, which is a main component of biofilm. Lp.LTA also attenuated the biding of fluorescein isothiocyanate-conjugated dextran to S. mutans, which is known to have a high affinity to exopolysaccharide on S. mutans. Dealanylated Lp.LTA did not inhibit biofilm formation of S. mutans implying that D-alanine moieties in the Lp.LTA structure were crucial for inhibition. Collectively, these results suggest that Lp.LTA attenuates S. mutans biofilm formation and could be used to develop effective anticaries agents. PMID:29420616

  13. Functional genomics of lactic acid bacteria: from food to health.

    Science.gov (United States)

    Douillard, François P; de Vos, Willem M

    2014-08-29

    Genome analysis using next generation sequencing technologies has revolutionized the characterization of lactic acid bacteria and complete genomes of all major groups are now available. Comparative genomics has provided new insights into the natural and laboratory evolution of lactic acid bacteria and their environmental interactions. Moreover, functional genomics approaches have been used to understand the response of lactic acid bacteria to their environment. The results have been instrumental in understanding the adaptation of lactic acid bacteria in artisanal and industrial food fermentations as well as their interactions with the human host. Collectively, this has led to a detailed analysis of genes involved in colonization, persistence, interaction and signaling towards to the human host and its health. Finally, massive parallel genome re-sequencing has provided new opportunities in applied genomics, specifically in the characterization of novel non-GMO strains that have potential to be used in the food industry. Here, we provide an overview of the state of the art of these functional genomics approaches and their impact in understanding, applying and designing lactic acid bacteria for food and health.

  14. Fermentation of D-Tagatose by Human Intestinal Bacteria and Dairy Lactic Acid Bacteria

    OpenAIRE

    Bertelsen, Hans; Andersen, Hans; Tvede, Michael

    2011-01-01

    A number of 174 normal or pathogenic human enteric bacteria and dairy lactic acid bacteria were screened for D-tagatose fermentation by incubation for 48 hours. Selection criteria for fermentation employed included a drop in pH below 5.5 and a distance to controls of more than 0.5. Only a few of the normal occurring enteric human bacteria were able to ferment D-tagatose, among those Enterococcus faecalis, Enterococcus faecium and Lactobacillus strains. D-Tagatose fermentation seems to be comm...

  15. Reactivation of latent HIV-1 by a wide variety of butyric acid-producing bacteria.

    Science.gov (United States)

    Imai, Kenichi; Yamada, Kiyoshi; Tamura, Muneaki; Ochiai, Kuniyasu; Okamoto, Takashi

    2012-08-01

    Latently infected cells harbor human immunodeficiency virus type 1 (HIV-1) proviral DNA copies integrated in heterochromatin, allowing persistence of transcriptionally silent proviruses. It is widely accepted that hypoacetylation of histone proteins by histone deacetylases (HDACs) is involved in maintaining the HIV-1 latency by repressing viral transcription. HIV-1 replication can be induced from latently infected cells by environmental factors, such as inflammation and co-infection with other microbes. It is known that a bacterial metabolite butyric acid inhibits catalytic action of HDAC and induces transcription of silenced genes including HIV-1 provirus. There are a number of such bacteria in gut, vaginal, and oral cavities that produce butyric acid during their anaerobic glycolysis. Since these organs are known to be the major site of HIV-1 transmission and its replication, we explored a possibility that explosive viral replication in these organs could be ascribable to butyric acid produced from anaerobic resident bacteria. In this study, we demonstrate that the culture supernatant of various bacteria producing butyric acid could greatly reactivate the latently-infected HIV-1. These bacteria include Fusobacterium nucleatum (commonly present in oral cavity, and gut), Clostridium cochlearium, Eubacterium multiforme (gut), and Anaerococcus tetradius (vagina). We also clarified that butyric acid in these culture supernatants could induce histone acetylation and HIV-1 replication by inhibiting HDAC. Our observations indicate that butyric acid-producing bacteria could be involved in AIDS progression by reactivating the latent HIV provirus and, subsequently, by eliminating such bacterial infection may contribute to the prevention of the AIDS development and transmission.

  16. Lactic acid bacteria and the human gastrointestinal tract

    DEFF Research Database (Denmark)

    Hove, H; Nørgaard, H; Mortensen, P B

    1999-01-01

    OBJECTIVE: This review summarises the effects of lactic acid bacteria on lactose malabsorption, bacterial/viral or antibiotic associated diarrhoea, and describes the impact of lactic acid bacteria on cancer and the fermentative products in the colon. RESULTS: Eight studies (including 78 patients......) demonstrated that lactase deficient subjects absorbed lactose in yogurt better than lactose in milk, while two studies (25 patients) did not support this. Two studies (22 patients) showed that unfermented acidophilus milk was absorbed better than milk, while six studies (68 patients) found no significant...... differences. Addition of lactose hydrolysing enzyme, lactase, to milk improved lactose malabsorption in seven studies (131 lactose malabsorbers), while one study (10 malabsorbers) demonstrated no improvement. Lactic acid bacteria alleviated travellers' diarrhoea in one study (94 individuals) while a study...

  17. Exopolysaccharide and lactic acid bacteria: Perception, functionality and prospects

    Directory of Open Access Journals (Sweden)

    Vivek K. Bajpai

    2016-03-01

    Full Text Available Lactic acid bacteria exhibit the most effective potential to divert significant amount of fermentable sugars towards the biosynthesis of functional exopolysaccharide. Exopolysaccharides from lactic acid bacteria are receiving a renewed interest due to the claims of human health benefits. This review provides an update on multiple uses and production of exopolysaccharides with major emphasis on their chemical properties, characterization, and some other molecular strategies adopted for their genetics and biological tailoring to better understand the process of exopolysaccharide production along with their antiviral efficacy with multiple modes of action. Additionally, microbiological, biochemical, nutritional and biotechnological aspects of exopolysaccharide production have also been discussed. Moreover, appro-priate suggestions have been made on lactic acid bacteria improvements, leading to enhanced production with advanced modification and production process that may contribute to the economic soundness of applications in food and pharmacological industries with this promising group of biomolecules.

  18. Nucleotide Metabolism and its Control in Lactic Acid Bacteria

    DEFF Research Database (Denmark)

    Kilstrup, Mogens; Hammer, Karin; Jensen, Peter Ruhdal

    2005-01-01

    Most metabolic reactions are connected through either their utilization of nucleotides or their utilization of nucleotides or their regulation by these metabolites. In this review the biosynthetic pathways for pyrimidine and purine metabolism in lactic acid bacteria are described including...... the interconversion pathways, the formation of deoxyribonucleotides and the salvage pathways for use of exogenous precursors. The data for the enzymatic and the genetic regulation of these pathways are reviewed, as well as the gene organizations in different lactic acid bacteria. Mutant phenotypes and methods...... for manipulation of nucleotide pools are also discussed. Our aim is to provide an overview of the physiology and genetics of nucleotide metabolism and its regulation that will facilitate the interpretation of data arising from genetics, metabolomics, proteomics, and transcriptomics in lactic acid bacteria....

  19. Typing some of lactic acid bacteria in Syria using PCR and FT-IR techniques

    International Nuclear Information System (INIS)

    Al-Mariri, A.; Sharabi, N. D.

    2008-11-01

    Lactic Acid Bacteria (LAB) are considered to be the most useful microorganisms. They are beneficial in flavoring foods, inhibiting pathogenic as well as spoilage bacteria in food products. The isolates of LAB were obtained from traditional Syrian dairy products (white cheese and curdled yogurt) obtained from different regions in Syria. The isolates were subjected to phenotypic characterization analyses. The PCR technique of bacterial DNA was evaluated as an advanced tool for the identification of LAB. It was found that strains: E. faecium, E. faecalis and S. thermophilus dominate in white cheese and in yogurt. Our results demonstrated that we could identify LAB using Fourier transform infrared spectroscopy (FT-IR) patterns. (Authors)

  20. Typing some of lactic acid bacteria in Syria using PCR and FT-IR techniques

    International Nuclear Information System (INIS)

    Al-Mariri, A.; Sharabi, N. D.

    2010-01-01

    Lactic Acid Bacteria (LAB) are considered to be the most useful microorganisms. They are beneficial in flavoring foods, inhibiting pathogenic as well as spoilage bacteria in food products. The isolates of LAB were obtained from traditional Syrian dairy products (white cheese and curdled yogurt) obtained from different regions in Syria. The isolates were subjected to phenotypic characterization analyses. The PCR technique of bacterial DNA was evaluated as an advanced tool for the identification of LAB. It was found that strains: E. faecium, E. faecalis and S. thermophilus dominate in white cheese and in yogurt. Our results demonstrated that we could identify LAB using Fourier transform infrared spectroscopy (FT-IR) patterns. (author)

  1. Effect of fermented broth from lactic acid bacteria on pathogenic bacteria proliferation.

    Science.gov (United States)

    Gutiérrez, S; Martínez-Blanco, H; Rodríguez-Aparicio, L B; Ferrero, M A

    2016-04-01

    In this study, the effect that 5 fermented broths of lactic acid bacteria (LAB) strains have on the viability or proliferation and adhesion of 7 potentially pathogenic microorganisms was tested. The fermented broth from Lactococcus lactis C660 had a growth inhibitory effect on Escherichia coli K92 that reached of 31%, 19% to Pseudomonas fluorescens, and 76% to Staphylococcus epidermidis. The growth of Staph. epidermidis was negatively affected to 90% by Lc. lactis 11454 broth, whereas the growth of P. fluorescens (25%) and both species of Staphylococcus (35% to Staphylococcus aureus and 76% to Staph. epidermidis) were inhibited when they were incubated in the presence of Lactobacillus casei 393 broth. Finally, the fermented broth of Lactobacillus rhamnosus showed an inhibitory effect on growth of E. coli K92, Listeria innocua, and Staph. epidermidis reached values of 12, 28, and 76%, respectively. Staphylococcus epidermidis was the most affected strain because the effect was detected from the early stages of growth and it was completely abolished. The results of bacterial adhesion revealed that broths from Lc. lactis strains, Lactobacillus paracasei, and Lb. rhamnosus caused a loss of E. coli K92 adhesion. Bacillus cereus showed a decreased of adhesion in the presence of the broths of Lc. lactis strains and Lb. paracasei. Listeria innocua adhesion inhibition was observed in the presence of Lb. paracasei broth, and the greatest inhibitory effect was registered when this pathogenic bacterium was incubated in presence of Lc. lactis 11454 broth. With respect to the 2 Pseudomonas, we observed a slight adhesion inhibition showed by Lactobacillus rhamnosus broth against Pseudomonas putida. These results confirm that the effect caused by the different LAB assayed is also broth- and species-specific and reveal that the broth from LAB tested can be used as functional bioactive compounds to regulate the adhesion and biofilm synthesis and ultimately lead to preventing food and

  2. Isolation and Characterization of Lactic Acid Bacteria from Inasua

    Directory of Open Access Journals (Sweden)

    Ferymon Mahulette

    2017-04-01

    Full Text Available Inasua is a traditionally product of wet salt fish fermentation produced by Teon, Nila and Serua (TNS Communities in Central Maluku, Indonesia. The community made this fermented fish to anticipate the lean time when fisherman could not go to sea.  The  fish that used as inasua raw material is demersal fishes that live around coral reefs, such as Samandar fish (Siganatus guttatus, Gala-gala fish (Lutjanus sp. and Sikuda fish (Lethrinus ornatus. The objective of the research was to isolate and characterize of bacterial indigenous in  Inasua from three producers in Seram Island. The measurement of pH from inasua samples were 5.9, 5.0 and 5.8, respectively. The highest number of lactic acid bacteria was found from  Gala – gala inasua was 2,5x107 cfu/g sample. Isolation of all isolates bacteria from inasua showed that a total of 7 isolates of bacteria was obtained  from Samadar inasua, 9 isolates from  Gala-gala inasua, and 7 isolates from  Sikuda inasua.  From a total of 23 isolates, only 6 isolates had characteristic as lactic acid bacteria that were Gram  positive, negative catalase, and cocci shape. The microscopic characteristics  of the isolates are coccid in pairs or uniforms which combine to form tetrads. Carbohydrate utilization test  of selected isolate by using API 50 CHB kit indicated that 13 carbohydrates are fermented by these isolates  after incubation for 48 hours. The research  was concluded that the dominant bacteria in inasua sample  is  cocci-lactic acid bacteria. Keywords : fermented fish, inasua, lactic acid bacteria, MRSA medium

  3. Inhibition of Staphylococcus aureus by the commensal bacteria of human milk.

    Science.gov (United States)

    Heikkilä, M P; Saris, P E J

    2003-01-01

    To study the bacterial diversity in expressed human milk with a focus on detecting bacteria with an antimicrobial activity against Staphylococcus aureus, known as a causative agent of maternal breast infections and neonatal infections. Random isolates (n = 509) were collected from breast milk samples (n = 40) of healthy lactating women, genotypically identified, and tested for antimicrobial activity against Staph. aureus. Commensal staphylococci (64%) and oral streptococci (30%), with Staph. epidermidis, Strep. salivarius, and Strep. mitis as the most frequent isolates, were the predominant bacterial species in breast milk. One-fifth of Staph. epidermidis and half of Strep. salivarius isolates suppressed growth of Staph. aureus. Enterococci (Ent. faecalis), isolated from 7.5% of samples, and lactic acid bacteria (LAB) (Lactobacillus rhamnosus, Lact. crispatus, Lactococcus lactis, Leuconoctoc mesenteroides), isolated from 12.5% of samples, were also effective against Staph. aureus. One L. lactis isolate was shown to produce nisin, a bacteriocin used in food industry to prevent bacterial pathogens and spoilage. Expressed breast milk contains commensal bacteria, which inhibit Staph. aureus. The strains inhibitory against the pathogen Staph. aureus have potential use as bacteriotherapeutic agents in preventing neonatal and maternal breast infections caused by this bacterium.

  4. Potential of lactic acid bacteria as suppressors of wine allergies

    Directory of Open Access Journals (Sweden)

    Yıldırım Hatice Kalkan

    2017-01-01

    Full Text Available Allergens causes some symptoms as all asthma, allergic conjunctivitis, and allergic rhinitis. These symptoms are seen twice as many in women than in men. The major wine allergens reported in wines are endochitinase 4A and lipid-transfer protein (LTP. This review deal with possibilities of using lactic acid bacteria as suppressors of wine allergies. Phenolic compounds present in wines have not only antioxidant properties causing radical scavenging but also some special properties reported in many in vitro studies as regulating functions in inflammatory cells as mast cells. So what is the role of lactic acid bacteria in these cases? Lactic acid bacteria are used during malolactic fermentation step of wine production with purpose of malic acid reduction. During this bioconversion complex phenolic compounds could be hydrolysed by bacterial enzymes to their aglycone forms. Obtained aglycons could pass through the intestinal epithelium of human and allowed reduction of IgE antibody production by affecting Th1/ Th2 ratio. Considering different contents and quantities of phenols in different grape varieties and consequently in different wines more studies are required in order to determine which lactic acid bacteria and strains could be effective in suppressing wine allergens.

  5. Ammonia production by human faecal bacteria, and the enumeration, isolation and characterization of bacteria capable of growth on peptides and amino acids

    Directory of Open Access Journals (Sweden)

    Richardson Anthony J

    2013-01-01

    Full Text Available Abstract Background The products of protein breakdown in the human colon are considered to be detrimental to gut health. Amino acid catabolism leads to the formation of sulfides, phenolic compounds and amines, which are inflammatory and/or precursors to the formation of carcinogens, including N-nitroso compounds. The aim of this study was to investigate the kinetics of protein breakdown and the bacterial species involved. Results Casein, pancreatic casein hydrolysate (mainly short-chain peptides or amino acids were incubated in vitro with suspensions of faecal bacteria from 3 omnivorous and 3 vegetarian human donors. Results from the two donor groups were similar. Ammonia production was highest from peptides, followed by casein and amino acids, which were similar. The amino acids metabolized most extensively were Asp, Ser, Lys and Glu. Monensin inhibited the rate of ammonia production from amino acids by 60% (P = 0.001, indicating the involvement of Gram-positive bacteria. Enrichment cultures were carried out to investigate if, by analogy with the rumen, there was a significant population of asaccharolytic, obligately amino acid-fermenting bacteria (‘hyper-ammonia-producing’ bacteria; HAP in the colon. Numbers of bacteria capable of growth on peptides or amino acids alone averaged 3.5% of the total viable count, somewhat higher than the rumen. None of these were HAP, however. The species enriched included Clostridium spp., one of which was C. perfringens, Enterococcus, Shigella and Escherichia coli. Conclusions Protein fermentation by human faecal bacteria in the absence of sugars not only leads to the formation of hazardous metabolic products, but also to the possible proliferation of harmful bacteria. The kinetics of protein metabolism were similar to the rumen, but HAP bacteria were not found.

  6. Acetic acid bacteria: A group of bacteria with versatile biotechnological applications.

    Science.gov (United States)

    Saichana, Natsaran; Matsushita, Kazunobu; Adachi, Osao; Frébort, Ivo; Frebortova, Jitka

    2015-11-01

    Acetic acid bacteria are gram-negative obligate aerobic bacteria assigned to the family Acetobacteraceae of Alphaproteobacteria. They are members of the genera Acetobacter, Gluconobacter, Gluconacetobacter, Acidomonas, Asaia, Kozakia, Swaminathania, Saccharibacter, Neoasaia, Granulibacter, Tanticharoenia, Ameyamaea, Neokomagataea, and Komagataeibacter. Many strains of Acetobacter and Komagataeibacter have been known to possess high acetic acid fermentation ability as well as the acetic acid and ethanol resistance, which are considered to be useful features for industrial production of acetic acid and vinegar, the commercial product. On the other hand, Gluconobacter strains have the ability to perform oxidative fermentation of various sugars, sugar alcohols, and sugar acids leading to the formation of several valuable products. Thermotolerant strains of acetic acid bacteria were isolated in order to serve as the new strains of choice for industrial fermentations, in which the cooling costs for maintaining optimum growth and production temperature in the fermentation vessels could be significantly reduced. Genetic modifications by adaptation and genetic engineering were also applied to improve their properties, such as productivity and heat resistance. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Characterization of Lactic Acid Bacteria (LAB) isolated from Indonesian shrimp paste (terasi)

    Science.gov (United States)

    Amalia, U.; Sumardianto; Agustini, T. W.

    2018-02-01

    Shrimp paste was one of fermented products, popular as a taste enhancer in many dishes. The processing of shrimp paste was natural fermentation, depends on shrimp it self and the presence of salt. The salt inhibits the growth of undesirable microorganism and allows the salt-tolerant lactic acid bacteria (LAB) to ferment the protein source to lactic acids. The objectives of this study were to characterize LAB isolated from Indonesian shrimp paste or "Terasi" with different times of fermentation (30, 60 and 90 days). Vitech analysis showed that there were four strains of the microorganism referred to as lactic acid bacteria (named: LABS1, LABS2, LABS3 and LABS4) with 95% sequence similarity. On the basis of biochemical, four isolates represented Lactobacillus, which the name Lactobacillus plantarum is proposed. L.plantarum was play role in resulting secondary metabolites, which gave umami flavor in shrimp paste.

  8. Discrimination of wine lactic acid bacteria by Raman spectroscopy.

    Science.gov (United States)

    Rodriguez, Susan B; Thornton, Mark A; Thornton, Roy J

    2017-08-01

    Species of Lactobacillus, Pediococcus, Oenococcus, and Leuconostoc play an important role in winemaking, as either inoculants or contaminants. The metabolic products of these lactic acid bacteria have considerable effects on the flavor, aroma, and texture of a wine. However, analysis of a wine's microflora, especially the bacteria, is rarely done unless spoilage becomes evident, and identification at the species or strain level is uncommon as the methods required are technically difficult and expensive. In this work, we used Raman spectral fingerprints to discriminate 19 strains of Lactobacillus, Pediococcus, and Oenococcus. Species of Lactobacillus and Pediococcus and strains of O. oeni and P. damnosus were classified with high sensitivity: 86-90 and 84-85%, respectively. Our results demonstrate that a simple, inexpensive method utilizing Raman spectroscopy can be used to accurately identify lactic acid bacteria isolated from wine.

  9. Technologically important properties of lactic acid bacteria isolated ...

    African Journals Online (AJOL)

    Technologically important properties of lactic acid bacteria isolated from raw milk of three breeds of Algerian dromedary ( Camelus dromedarius ) ... isolated from Algerian dromedary milks that showed potentially important properties suggest that they are good candidate for camels milk processing or other dairy fermentation ...

  10. Isolation and screening of lactic acid bacteria, Lactococcus lactis ...

    African Journals Online (AJOL)

    In aquaculture probiotic feeding could play a crucial role in developing microbial control strategies, since disease outbreaks are recognized as important constraints to aquaculture production and the fear of antibiotic resistance. In this study, lactic acid bacteria (LAB) strains from the intestinal tissue of African catfish Clarias ...

  11. Analysis of some functional properties of acetic acid bacteria ...

    African Journals Online (AJOL)

    SARAH

    2014-03-31

    Mar 31, 2014 ... Analysis of some functional properties of acetic acid bacteria involved in Ivorian cocoa fermentation. Wilfried YAO, Honoré G. OUATTARA, Bernadette GOUALIE, Souleymane SOUMAHORO, Sébastien. NIAMKE. Laboratoire de Biotechnologies, UFR Biosciences, Université Félix HOUPHOUET-BOIGNY ...

  12. Identification of Lactic Acid Bacteria isolated from Opaque beer ...

    African Journals Online (AJOL)

    A study was carried out to identify lactic acid bacteria (LAB) isolated from chibuku that would be later assessed for potential as starter cultures. Thirty-eight isolates were Gram stained and the 20, which were Gram positive, were identified to genus level using morphological, physiological and biochemical tests. Five genera ...

  13. Antimicrobial susceptibility pattern of lactic acid bacteria isolated ...

    African Journals Online (AJOL)

    Currently, the efficacies of antimicrobials have been threatened due to the development of resistance to antibiotics by some microorganisms. Lactic acid bacteria (LAB) from fermented products, may act as reservoir of antimicrobial resistance-genes that could be transferred to pathogens, either in the food matrix or in the ...

  14. Mucosal Vaccination and Therapy with Genetically Modified Lactic Acid Bacteria

    NARCIS (Netherlands)

    Wells, J.

    2011-01-01

    Lactic acid bacteria (LAB) have proved to be effective mucosal delivery vehicles that overcome the problem of delivering functional proteins to the mucosal tissues. By the intranasal route, both live and killed LAB vaccine strains have been shown to elicit mucosal and systemic immune responses that

  15. Recombinant lactic acid bacteria as mucosal biotherapeutic agents

    NARCIS (Netherlands)

    Daniel, C.; Roussel, Y.; Kleerebezem, M.; Pot, B.

    2011-01-01

    The safety status of lactic acid bacteria (LAB) and their capacity to survive the passage through the gastrointestinal tract (GI tract) have rendered them excellent candidates for the production of therapeutic proteins and their delivery in situ to the GI tract. During the past two decades, major

  16. Systems Biology of lactic acid bacteria: a critical review.

    NARCIS (Netherlands)

    Teusink, B.; Bachmann, H.; Molenaar, D.

    2011-01-01

    Understanding the properties of a system as emerging from the interaction of well described parts is the most important goal of Systems Biology. Although in the practice of Lactic Acid Bacteria (LAB) physiology we most often think of the parts as the proteins and metabolites, a wider interpretation

  17. Lactic acid bacteria in a changing legislative environment

    NARCIS (Netherlands)

    Feord, J.

    2002-01-01

    The benefits of using lactic acid bacteria in the food chain, both through direct consumption and production of ingredients, are increasingly recognised by the food industry and consumers alike. The regulatory environment surrounding these products is diverse, covering foods and food ingredients,

  18. Antimicrobial activities of lactic acid bacteria isolated from akamu ...

    African Journals Online (AJOL)

    Three lactic acid bacteria (LAB) isolates designated AS1, AS2 and KN4 isolated from kunun-zaki (a sorghum based non-alcoholic beverage widely consumed in Northern Nigeria) and identified as Lactobacillus plantarum, Lactobacillus brevis and Lactobacillus delbruckii, respectively, produced significant inhibitory ...

  19. Identification of exopolysaccharides-producing lactic acid bacteria ...

    African Journals Online (AJOL)

    Spacer region between 16S and 23 S rRNA genes of thirteen lactic acid bacteria strains from Burkina Faso fermented milk samples were amplified by the polymerase chain reaction (PCR). Lactobacillus delbrueckii, Lactobacillus acidophilus, Lactobacillus fermentum, Streptococcus thermophilus, Pediococcus spp, ...

  20. Evaluation of the probiotic potential of lactic acid bacteria isolated ...

    African Journals Online (AJOL)

    The probiotic-related characteristics of 55 strains of lactic acid bacteria isolated from the faeces of 3 - 6 months old breast-fed infants were determined. The API 50 CH and SDS-PAGE techniques were employed to ascertain the identity of the isolated strains. The predominant species among the isolated strains were ...

  1. Systems solutions by lactic acid bacteria: from paradigms to practice.

    Science.gov (United States)

    de Vos, Willem M

    2011-08-30

    Lactic acid bacteria are among the powerhouses of the food industry, colonize the surfaces of plants and animals, and contribute to our health and well-being. The genomic characterization of LAB has rocketed and presently over 100 complete or nearly complete genomes are available, many of which serve as scientific paradigms. Moreover, functional and comparative metagenomic studies are taking off and provide a wealth of insight in the activity of lactic acid bacteria used in a variety of applications, ranging from starters in complex fermentations to their marketing as probiotics. In this new era of high throughput analysis, biology has become big science. Hence, there is a need to systematically store the generated information, apply this in an intelligent way, and provide modalities for constructing self-learning systems that can be used for future improvements. This review addresses these systems solutions with a state of the art overview of the present paradigms that relate to the use of lactic acid bacteria in industrial applications. Moreover, an outlook is presented of the future developments that include the transition into practice as well as the use of lactic acid bacteria in synthetic biology and other next generation applications.

  2. Novel applications of Lactic Acid Bacteria (LAB) and Recombinant ...

    African Journals Online (AJOL)

    Lactic acid bacteria (LAB), present in intestines of most animals and humans, plays an important role as starters of fermented food products where it acts as a biopreservative, preventing spoilage by pathogenic microorganisms through acidification, competition for essential nutrients, and / or production of inhibitory ...

  3. Mixed cultures of Kimchi lactic acid bacteria show increased cell ...

    African Journals Online (AJOL)

    ufuoma

    bioactive substances. This suggests that Lactobacilli isolated from kimchi could potentially be used for functional food. Foods containing probiotics can eliminate constipation symptoms arising from irregular eating habits, stress and excessive dieting (Kapka-Skrzypczak et al., 2012). Mixed cultures of lactic acid bacteria have.

  4. Lactic Acid Bacteria in Health and Disease | Ongol | Rwanda ...

    African Journals Online (AJOL)

    The genera, lactic acid bacteria (LAB) have been used by humans in production of fermented foods since time immemorial and in some ancient communities; consumption of LAB fermented foods products was associated with improved health. Currently there is a keen scientific interest in developed countries on health ...

  5. Short Communication Antibacterial Activities of Lactic Acid Bacteria ...

    African Journals Online (AJOL)

    2011-12-20

    Dec 20, 2011 ... A total of four lactic acid bacteria were isolated as follows: Pediococcus pentosaceus 2 from cucumber, Lactobacillus cellobiosus from cabbage, Lactobacillus salivarius and Lactobacillus plantarum 1 from lettuce. Pediococcus pentosaceus 2 and L. salivarius showed inhibitory effects on all the standard ...

  6. Differentiation studies of predominant lactic acid bacteria isolated ...

    African Journals Online (AJOL)

    Jane

    2011-08-08

    Aug 8, 2011 ... Several authors have noted that Lactobacillus spp. con- stitute the majority of lactic acid bacteria of the fermented cassava preparation (Rascana, 1986; Rahayu, 1996). Unfortunately, the identification of these LAB in growol is just based on their morphological and physiological characteristics in genus ...

  7. Fumonisin B 1 Reduction in Lactic Acid Bacteria Fermentation of ...

    African Journals Online (AJOL)

    This study investigated how fermentation can promote fumonisin B1 reduction in maize-based porridges. Four starter culture of lactic acid bacteria (Lactobacillus plantarum, Pediococcus pentosaceus, Lactobacillus casei and Lactobacillus fermentum) were used, porridge samples was spiked with fumonisins B1 and allowed ...

  8. Biochemical and functional properties of lactic acid bacteria isolated ...

    African Journals Online (AJOL)

    Objective: Fermentation is an important step in the post-harvest processing of cocoa beans. The quality of beans and chocolate depends strongly on the type and characteristics of microbial strains involved in the fermentation. This study investigates some functional properties of lactic acid bacteria (LAB), involved in Côte ...

  9. Isolation and screening of lactic acid bacteria, Lactococcus lactis ...

    African Journals Online (AJOL)

    Yomi

    2012-04-10

    Apr 10, 2012 ... In aquaculture probiotic feeding could play a crucial role in developing microbial control strategies, since disease outbreaks are recognized as important constraints to aquaculture production and the fear of antibiotic resistance. In this study, lactic acid bacteria (LAB) strains from the intestinal tissue of.

  10. Heme and menaquinone induced electron transport in lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Santos Filipe

    2009-05-01

    Full Text Available Abstract Background For some lactic acid bacteria higher biomass production as a result of aerobic respiration has been reported upon supplementation with heme and menaquinone. In this report, we have studied a large number of species among lactic acid bacteria for the existence of this trait. Results Heme- (and menaquinone stimulated aerobic growth was observed for several species and genera of lactic acid bacteria. These include Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacilllus brevis, Lactobacillus paralimentarius, Streptococcus entericus and Lactococcus garviae. The increased biomass production without further acidification, which are respiration associated traits, are suitable for high-throughput screening as demonstrated by the screening of 8000 Lactococcus lactis insertion mutants. Respiration-negative insertion-mutants were found with noxA, bd-type cytochrome and menaquinol biosynthesis gene-disruptions. Phenotypic screening and in silico genome analysis suggest that respiration can be considered characteristic for certain species. Conclusion We propose that the cyd-genes were present in the common ancestor of lactic acid bacteria, and that multiple gene-loss events best explains the observed distribution of these genes among the species.

  11. Genetic manipulation of the peptidolytic system in lactic acid bacteria

    NARCIS (Netherlands)

    Kok, J; Venema, G

    1995-01-01

    Due to their presumed involvenment in product flavour the peptidases of lactic acid bacteria have been subject to extensive research. A major breakthrough, was the isolation and purification of the various enzymes to homogeniety. This allowed a reevaluation of the number of different enzymes in one

  12. Systems solutions by lactic acid bacteria: from paradigms to practice

    NARCIS (Netherlands)

    Vos, de W.M.

    2011-01-01

    Lactic acid bacteria are among the powerhouses of the food industry, colonize the surfaces of plants and animals, and contribute to our health and well-being. The genomic characterization of LAB has rocketed and presently over 100 complete or nearly complete genomes are available, many of which

  13. Effects of lactic acid bacteria contamination on lignocellulosic ethanol fermentation

    Science.gov (United States)

    Slower fermentation rates, mixed sugar compositions, and lower sugar concentrations may make lignocellulosic fermentations more susceptible to contamination by lactic acid bacteria (LAB), which is a common and costly problem to the corn-based fuel ethanol industry. To examine the effects of LAB con...

  14. Quorum sensing-controlled gene expression in lactic acid bacteria

    NARCIS (Netherlands)

    Kuipers, Oscar P.; Ruyter, Pascalle G.G.A. de; Kleerebezem, Michiel; Vos, Willem M. de

    1998-01-01

    Quorum sensing in lactic acid bacteria (LAB) involves peptides that are directly sensed by membrane-located histidine kinases, after which the signal is transmitted to an intracellular response regulator. This regulator in turn activates transcription of target genes, that commonly include the

  15. Repressive efficacy of lactic acid bacteria against the human ...

    African Journals Online (AJOL)

    Different strains of lactic acid bacteria (LAB) namely Lactobacillus acidophilus NCIM 2287, Lactobacillus plantarum NCIM 2085, Lactobacillus helveticus NCIM 2126 and Lactococcus lactis NCIM 2114 were procured from the National Chemical Laboratory (NCL) Pune, India. These LAB cells were individually (107 cfu/ml) ...

  16. Differentiation studies of predominant lactic acid bacteria isolated ...

    African Journals Online (AJOL)

    Twelve isolates known as weakly amylolytic lactic acid bacteria were isolated from different time during growol fermentation, a cassava based product from Indonesia. Differentiation tests of these strains were performed using molecular and phenotypic characterization. 16S subunit of the ribosomal RNA and phenylalanyl ...

  17. Controlled overproduction of proteins by lactic acid bacteria

    NARCIS (Netherlands)

    Kuipers, Oscar P.; Ruyter, Pascalle G.G.A. de; Kleerebezem, Michiel; Vos, Willem M. de

    1997-01-01

    Lactic acid bacteria are widely used in industrial food fermentations, contributing to flavour, texture and preservation of the fermented products. Here we describe recent advances in the development of controlled gene expression systems, which allow the regulated overproduction of any desirable

  18. Lactic acid bacteria : the bugs of the new millennium

    NARCIS (Netherlands)

    Konings, W.N; Kok, J.; Kuipers, O.P.; Poolman, B.

    2000-01-01

    Lactic acid bacteria (LABs) are widely used in the manufacturing of fermented food and are among the best-studied microorganisms. Detailed knowledge of a number of physiological traits has opened new potential applications for these organisms in the food industry, while other traits might be

  19. Advanced molecular tools for the identification of lactic acid bacteria

    NARCIS (Netherlands)

    Amor, Ben K.; Vaughan, E.E.; Vos, de W.M.

    2007-01-01

    Recent years have seen an explosion in the development and application of molecular tools for identifying microbes and analyzing their activity. These tools are increasingly applied to strains of lactic acid bacteria (LAB), including those used in fermentation and as well as those marketed as

  20. Antagonistic pattern of lactic acid bacteria against native spoilage ...

    African Journals Online (AJOL)

    CIBA

    2012-11-08

    Nov 8, 2012 ... Different strains of lactic acid bacteria (LAB) namely Lactobacillus acidophilus NCIM 2287,. Lactobacillus plantarum NCIM 2085, Lactobacillus helveticus NCIM 2126 and Lactococcus lactis NCIM. 2114 were procured from the National Chemical Laboratory (NCL) Pune, India. These LAB cells were.

  1. Antibacterial activities of lactic acid bacteria isolated from cow ...

    African Journals Online (AJOL)

    Objective: To determine the antimicrobial activity of cow's intestinal Lactic acid bacteria (LAB) against enteric commensals. Method: ... Conclusion: This study shows that LAB from cow faeces possess considerable antimicrobial activity against resistant Es- cherichia ... tries1. The meat from cattle, goat, sheep, pig and poul-.

  2. Analysis of some functional properties of acetic acid bacteria ...

    African Journals Online (AJOL)

    Objective: To investigate some functional properties of acetic acid bacteria (AAB), involved in Côte d'Ivoire cocoa fermentation. Methods and results: Six day heap fermentation on banana leaves was conducted at farm level and AAB growth was monitored during this process at 24 h interval by numeration on plate agar.

  3. Characterization And Identification Of Lactic Acid Bacteria From ...

    African Journals Online (AJOL)

    $hr3k

    2013-06-05

    Jun 5, 2013 ... Diversity and density of lactic acid bacteria from indigenous dahi were studied by the determination of morphological, cultural, physiological and biochemical characteristics. A total of 143 isolates were identified phenotypically and divided into three genera: Lactobacillus, Lactococcus and Streptococcus.

  4. AKTIVITAS ANTIKAPANG BAKTERI ASAM LAKTAT TERHADAP PERTUMBUHAN KAPANG KONTAMINAN KEJI [Antimycotic Activity of Lactic Acid Bacteria on the Growth of Cheese Contaminating Molds

    OpenAIRE

    S. Styahadi3); L Nuraida2); Fatim Illianingtyas1); B S.L Jenie2)

    2006-01-01

    Local cheese is frequently contaminated by toxigenic molds which is harmful for human health. Lactic acid bacteria have been proven to inhibit the growth of toxigenic mold in some food products. The research was aimed to study the activity of indigenous lactic acid bacteria to inhibit the growth of toxigenic molds in local cheese. The molds studied were isolated from local cheese production (Gouda type). The cheese contaminating molds were identified as Penicillium sp. and Aspergillus sp. Nin...

  5. Molecular identification and physiological characterization of yeasts, lactic acid bacteria and acetic acid bacteria isolated from heap and box cocoa bean fermentations in West Africa.

    Science.gov (United States)

    Visintin, Simonetta; Alessandria, Valentina; Valente, Antonio; Dolci, Paola; Cocolin, Luca

    2016-01-04

    Yeast, lactic acid bacteria (LAB) and acetic acid bacteria (AAB) populations, isolated from cocoa bean heap and box fermentations in West Africa, have been investigated. The fermentation dynamicswere determined by viable counts, and 106 yeasts, 105 LAB and 82 AAB isolateswere identified by means of rep-PCR grouping and sequencing of the rRNA genes. During the box fermentations, the most abundant species were Saccharomyces cerevisiae, Candida ethanolica, Lactobacillus fermentum, Lactobacillus plantarum, Acetobacter pasteurianus and Acetobacter syzygii, while S. cerevisiae, Schizosaccharomyces pombe, Hanseniaspora guilliermondii, Pichia manshurica, C. ethanolica, Hanseniaspora uvarum, Lb. fermentum, Lb. plantarum, A. pasteurianus and Acetobacter lovaniensis were identified in the heap fermentations. Furthermore, the most abundant species were molecularly characterized by analyzing the rep-PCR profiles. Strains grouped according to the type of fermentations and their progression during the transformation process were also highlighted. The yeast, LAB and AAB isolates were physiologically characterized to determine their ability to grow at different temperatures, as well as at different pH, and ethanol concentrations, tolerance to osmotic stress, and lactic acid and acetic acid inhibition. Temperatures of 45 °C, a pH of 2.5 to 3.5, 12% (v/v) ethanol and high concentrations of lactic and acetic acid have a significant influence on the growth of yeasts, LAB and AAB. Finally, the yeastswere screened for enzymatic activity, and the S. cerevisiae, H. guilliermondii, H. uvarumand C. ethanolica species were shown to possess several enzymes that may impact the quality of the final product.

  6. Investigation of antibacterial activity of Lactic Acid Bacteria isolated from traditional kordish cheese in comparison with commercial strains

    Directory of Open Access Journals (Sweden)

    Fereshteh Tofangsazan

    2013-12-01

    Full Text Available Background and Aim: The health benefits of lactic acid bacteria in human, especially their anti-pathogenic properties has been the focus of recent interests. The objective of this study was to investigate the antibacterial activity of lactic acid bacteria (LAB isolated from traditional Kurdish cheese against a few bacterial pathogens. Materials and Methods: The cell free culture supernatant of LAB isolated from Kurdish cheese which was treated with heat and NaOH were tested for their antibacterial activity by Agar Disk Diffusion method. Moreover, Minimum Inhibition Concentration and Co-aggregation of LAB against pathogens were determined. Each test was repeated for three times. Results: The LAB isolates, in comparison with commercial lactic acid bacteria, showed suitable antibacterial activity. Heating the bacterial supernatant eliminated its anti-bacterial property; however, alkali treatment did not have any effect. The Minimum Inhibition Concentration did not show significant differences between native and commercial lactic acid bacteria; however, the native LAB showed suitable co-aggregation with pathogens. Conclusion: Traditional lactic acid bacteria and their metabolites can inhibit growth of pathogens. This shows the positive role of LAB in human health which necessitates their increase usage as natural antimicrobial agent.

  7. Acetic acid bacteria spoilage of bottled red wine -- a review.

    Science.gov (United States)

    Bartowsky, Eveline J; Henschke, Paul A

    2008-06-30

    Acetic acid bacteria (AAB) are ubiquitous organisms that are well adapted to sugar and ethanol rich environments. This family of Gram-positive bacteria are well known for their ability to produce acetic acid, the main constituent in vinegar. The oxidation of ethanol through acetaldehyde to acetic acid is well understood and characterised. AAB form part of the complex natural microbial flora of grapes and wine, however their presence is less desirable than the lactic acid bacteria and yeast. Even though AAB were described by Pasteur in the 1850s, wine associated AAB are still difficult to cultivate on artificial laboratory media and until more recently, their taxonomy has not been well characterised. Wine is at most risk of spoilage during production and the presence of these strictly aerobic bacteria in grape must and during wine maturation can be controlled by eliminating, or at least limiting oxygen, an essential growth factor. However, a new risk, spoilage of wine by AAB after packaging, has only recently been reported. As wine is not always sterile filtered prior to bottling, especially red wine, it often has a small resident bacterial population (wines, sealed with natural cork closures, and stored in a vertical upright position may develop spoilage by acetic acid bacteria. This spoilage is evident as a distinct deposit of bacterial biofilm in the neck of the bottle at the interface of the wine and the headspace of air, and is accompanied with vinegar, sherry, bruised apple, nutty, and solvent like off-aromas, depending on the degree of spoilage. This review focuses on the wine associated AAB species, the aroma and flavour changes in wine due to AAB metabolism, discusses the importance of oxygen ingress into the bottle and presents a hypothesis for the mechanism of spoilage of bottled red wine.

  8. Review - Lactic acid bacteria in traditional fermented Asian foods.

    Science.gov (United States)

    Azam, Mariya; Mohsin, Mashkoor; Ijaz, Hira; Tulain, Ume Ruqia; Ashraf, Muhammad Adnan; Fayyaz, Ahad; Abadeen, Zainul; Kamran, Qindeel

    2017-09-01

    Lactic acid bacteria play vital roles in various fermented foods in Asia. This paper reviews many types of the world's lactic acid fermented foods and discusses the beneficial effects of lactic acid fermentation of food. The lactic acid bacteria associated with foods now include species of the genera Carnobacterium, Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Oenococcus, Pediococcus, Streptococcus, Tetragenococcus, Vagococcus and Weissella. Lactic acid bacteria (LAB) are involved in many fermentation processes of Asian traditional foods, demonstrating their profound effects on improving food quality and food safety. During the past few decades' interest has arisen in the use of the varied antagonistic activities of LAB to extent the shelf-life of protein-rich products such as meats and fish. This review article outlines the main types of LAB fermentation as well as their typical fermented foods such as idli, kishk, sauerkraut, koumiss, Suan-tsai, stinky tofu, Chinese sausage and kefir. The roles of LAB and the reasons for their common presence are also discussed.

  9. Isolation of lactic acid-forming bacteria from biogas plants.

    Science.gov (United States)

    Bohn, Jelena; Yüksel-Dadak, Aytül; Dröge, Stefan; König, Helmut

    2017-02-20

    Direct molecular approaches provide hints that lactic acid bacteria play an important role in the degradation process of organic material to methanogenetic substrates in biogas plants. However, their diversity in biogas fermenter samples has not been analyzed in detail yet. For that reason, five different biogas fermenters, which were fed mainly with maize silage and manure from cattle or pigs, were examined for the occurrence of lactic acid-forming bacteria. A total of 197 lactic acid-forming bacterial strains were isolated, which we assigned to 21 species, belonging to the genera Bacillus, Clostridium, Lactobacillus, Pediococcus, Streptococcus and Pseudoramibacter-related. A qualitative multiplex system and a real-time quantitative PCR could be developed for most isolates, realized by the selection of specific primers. Their role in biogas plants was discussed on the basis of the quantitative results and on physiological data of the isolates. Copyright © 2016. Published by Elsevier B.V.

  10. Relation between chemotaxis and consumption of amino acids in bacteria

    Science.gov (United States)

    Yang, Yiling; M. Pollard, Abiola; Höfler, Carolin; Poschet, Gernot; Wirtz, Markus; Hell, Rüdiger

    2015-01-01

    Summary Chemotaxis enables bacteria to navigate chemical gradients in their environment, accumulating toward high concentrations of attractants and avoiding high concentrations of repellents. Although finding nutrients is likely to be an important function of bacterial chemotaxis, not all characterized attractants are nutrients. Moreover, even for potential nutrients, the exact relation between the metabolic value of chemicals and their efficiency as chemoattractants has not been systematically explored. Here we compare the chemotactic response of amino acids with their use by bacteria for two well‐established models of chemotactic behavior, E scherichia coli and B acillus subtilis. We demonstrate that in E . coli chemotaxis toward amino acids indeed strongly correlates with their utilization. However, no such correlation is observed for B . subtilis, suggesting that in this case, the amino acids are not followed because of their nutritional value but rather as environmental cues. PMID:25807888

  11. Inhibition of Dermatophilus congolensis by substances produced by bacteria found on the skin.

    Science.gov (United States)

    Kingali, J M; Heron, I D; Morrow, A N

    1990-04-01

    Bacteria, isolated from the skins of clinically normal sheep, were tested for inhibitory activity against Dermatophilus congolensis grown in vitro. Out of 85 bacterial isolates, 19, mainly Bacillus spp., showed zones of inhibition when grown together with D. congolensis. The inhibitory activity was shown to be due to the metabolites released by the bacteria.

  12. Lactic acid bacteria as a cell factory for riboflavin production.

    Science.gov (United States)

    Thakur, Kiran; Tomar, Sudhir Kumar; De, Sachinandan

    2016-07-01

    Consumers are increasingly becoming aware of their health and nutritional requirements, and in this context, vitamins produced in situ by microbes may suit their needs and expectations. B groups vitamins are essential components of cellular metabolism and among them riboflavin is one of the vital vitamins required by bacteria, plants, animals and humans. Here, we focus on the importance of microbial production of riboflavin over chemical synthesis. In addition, genetic abilities for riboflavin biosynthesis by lactic acid bacteria are discussed. Genetically modified strains by employing genetic engineering and chemical analogues have been developed to enhance riboflavin production. The present review attempts to collect the currently available information on riboflavin production by microbes in general, while placing greater emphasis on food grade lactic acid bacteria and human gut commensals. For designing riboflavin-enriched functional foods, proper selection and exploitation of riboflavin-producing lactic acid bacteria is essential. Moreover, eliminating the in situ vitamin fortification step will decrease the cost of food production. © 2015 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  13. Antibacterial and antibiofilm activities of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) against periodontopathic bacteria.

    Science.gov (United States)

    Sun, Mengjun; Zhou, Zichao; Dong, Jiachen; Zhang, Jichun; Xia, Yiru; Shu, Rong

    2016-10-01

    Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are two major omega-3 polyunsaturated fatty acids (n-3 PUFAs) with antimicrobial properties. In this study, we evaluated the potential antibacterial and antibiofilm activities of DHA and EPA against two periodontal pathogens, Porphyromonas gingivalis (P. gingivalis) and Fusobacterium nucleatum (F. nucleatum). MTT assay showed that DHA and EPA still exhibited no cytotoxicity to human oral tissue cells when the concentration came to 100 μM and 200 μM, respectively. Against P. gingivalis, DHA and EPA showed the same minimum inhibitory concentration (MIC) of 12.5 μM, and a respective minimum bactericidal concentration (MBC) of 12.5 μM and 25 μM. However, the MIC and MBC values of DHA or EPA against F. nucleatum were both greater than 100 μM. For early-stage bacteria, DHA or EPA displayed complete inhibition on the planktonic growth and biofilm formation of P. gingivalis from the lowest concentration of 12.5 μM. And the planktonic growth of F. nucleatum was slightly but not completely inhibited by DHA or EPA even at the concentration of 100 μM, however, the biofilm formation of F. nucleatum at 24 h was significantly restrained by 100 μM EPA. For exponential-phase bacteria, 100 μM DHA or EPA completely killed P. gingivalis and significantly decreased the viable counts of F. nucleatum. Meanwhile, the morphology of P. gingivalis was apparently damaged, and the virulence factor gene expression of P. gingivalis and F. nucleatum was strongly downregulated. Besides, the viability and the thickness of mature P. gingivalis biofilm, together with the viability of mature F. nucleatum biofilm were both significantly decreased in the presence of 100 μM DHA or EPA. In conclusion, DHA and EPA possessed antibacterial activities against planktonic and biofilm forms of periodontal pathogens, which suggested that DHA and EPA might be potentially supplementary therapeutic agents for prevention

  14. Antibacterial and Antibiofilm Activity of Lactic Acid Bacteria Isolated from Traditional Artisanal Milk Cheese from Northeast China Against Enteropathogenic Bacteria.

    Science.gov (United States)

    Cui, Xingyang; Shi, Yunjia; Gu, Shanshan; Yan, Xin; Chen, Hongyan; Ge, Junwei

    2017-12-07

    The present study aims to investigate the probiotic properties of novel strains of lactic acid bacteria isolated from traditional artisanal milk cheese from Northeast China and to explore their antibacterial activity against enteropathogenic bacteria. Of the 321 isolates, 86 exhibited survival in low pH, resistance to pancreatin, and tolerance to bile salts; of these, 12 inhibited the growth of more than seven enteropathogenic bacteria and exhibited antibiofilm activities against Staphylococcus aureus CMCC26003 and/or Escherichia coli CVCC230. Based on 16S ribosomal RNA sequence analysis, the 12 isolates were assigned to Lactobacillus plantarum (7), Lactobacillus helveticus (3), Pediococcus acidilactici (1), and Enterococcus faecium (1) species. In addition, 5 of the 12 strains were susceptible to most of the tested antibiotics. Furthermore, four strains with sensitivity to antibiotics showed significantly high levels of hydrophobicity similar to or better than the reference strain Lactobacillus rhamnosus GG. Moreover, three strains were confirmed safe through non-hemolytic activities and bacterial translocation. Overall, the selected Lact. plantarum 27053 and 27172 and Lact. helveticus 27058 strains can be considered potential probiotic strains and candidates for further application in functional food and prevention or treatment of gastrointestinal diseases.

  15. Probiotic bacteria survive in Cheddar cheese and modify populations of other lactic acid bacteria.

    Science.gov (United States)

    Ganesan, B; Weimer, B C; Pinzon, J; Dao Kong, N; Rompato, G; Brothersen, C; McMahon, D J

    2014-06-01

    Starter lactic acid bacteria in Cheddar cheese face physico-chemical stresses during manufacture and ageing that alter their abilities to survive and to interact with other bacterial populations. Nonstarter bacteria are derived from milk handling, cheese equipment and human contact during manufacture. Probiotic bacteria are added to foods for human health benefits that also encounter physiological stresses and microbial competition that may mitigate their survival during ageing. We added probiotic Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus paracasei and Bifidobacterium animalis subsp. lactis to full-fat, reduced-fat and low-fat Cheddar cheeses, aiming to study their survival over 270 days of ageing and to determine the role of the cheese matrix in their survival. Probiotic and other lactic acid bacterial populations were enumerated by quantitative PCR using primers specifically targeting the different bacterial genera or species of interest. Bifidobacteria were initially added at 10(6) CFU g(-1) cheese and survived variably in the different cheeses over the 270-day ageing process. Probiotic lactobacilli that were added at 10(7) CFU g(-1) cheese and incident nonstarter lactobacilli (initially at 10(8) CFU g(-1) cheese) increased by 10- to 100-fold over 270 days. Viable bacterial populations were differentiated using propidium monoazide followed by species-specific qPCR assays, which demonstrated that the starter and probiotic microbes survived over ageing, independent of cheese type. Addition of probiotic bacteria, at levels 100-fold below that of starter bacteria, modified starter and nonstarter bacterial levels. We demonstrated that starter lactococci, nonstarter lactobacilli and probiotic bacteria are capable of surviving throughout the cheesemaking and ageing process, indicating that delivery via hard cheeses is possible. Probiotic addition at lower levels may also alter starter and nonstarter bacterial survival. We applied qPCR to study

  16. A Glutamic Acid-Producing Lactic Acid Bacteria Isolated from Malaysian Fermented Foods

    Directory of Open Access Journals (Sweden)

    Bita Forghani

    2012-05-01

    Full Text Available L-glutamaic acid is the principal excitatory neurotransmitter in the brain and an important intermediate in metabolism. In the present study, lactic acid bacteria (218 were isolated from six different fermented foods as potent sources of glutamic acid producers. The presumptive bacteria were tested for their ability to synthesize glutamic acid. Out of the 35 strains showing this capability, strain MNZ was determined as the highest glutamic-acid producer. Identification tests including 16S rRNA gene sequencing and sugar assimilation ability identified the strain MNZ as Lactobacillus plantarum. The characteristics of this microorganism related to its glutamic acid-producing ability, growth rate, glucose consumption and pH profile were studied. Results revealed that glutamic acid was formed inside the cell and excreted into the extracellular medium. Glutamic acid production was found to be growth-associated and glucose significantly enhanced glutamic acid production (1.032 mmol/L compared to other carbon sources. A concentration of 0.7% ammonium nitrate as a nitrogen source effectively enhanced glutamic acid production. To the best of our knowledge this is the first report of glutamic acid production by lactic acid bacteria. The results of this study can be further applied for developing functional foods enriched in glutamic acid and subsequently γ-amino butyric acid (GABA as a bioactive compound.

  17. A Glutamic Acid-Producing Lactic Acid Bacteria Isolated from Malaysian Fermented Foods

    Science.gov (United States)

    Zareian, Mohsen; Ebrahimpour, Afshin; Bakar, Fatimah Abu; Mohamed, Abdul Karim Sabo; Forghani, Bita; Ab-Kadir, Mohd Safuan B.; Saari, Nazamid

    2012-01-01

    l-glutamaic acid is the principal excitatory neurotransmitter in the brain and an important intermediate in metabolism. In the present study, lactic acid bacteria (218) were isolated from six different fermented foods as potent sources of glutamic acid producers. The presumptive bacteria were tested for their ability to synthesize glutamic acid. Out of the 35 strains showing this capability, strain MNZ was determined as the highest glutamic-acid producer. Identification tests including 16S rRNA gene sequencing and sugar assimilation ability identified the strain MNZ as Lactobacillus plantarum. The characteristics of this microorganism related to its glutamic acid-producing ability, growth rate, glucose consumption and pH profile were studied. Results revealed that glutamic acid was formed inside the cell and excreted into the extracellular medium. Glutamic acid production was found to be growth-associated and glucose significantly enhanced glutamic acid production (1.032 mmol/L) compared to other carbon sources. A concentration of 0.7% ammonium nitrate as a nitrogen source effectively enhanced glutamic acid production. To the best of our knowledge this is the first report of glutamic acid production by lactic acid bacteria. The results of this study can be further applied for developing functional foods enriched in glutamic acid and subsequently γ-amino butyric acid (GABA) as a bioactive compound. PMID:22754309

  18. Nanosized Minicells Generated by Lactic Acid Bacteria for Drug Delivery

    Directory of Open Access Journals (Sweden)

    Huu Ngoc Nguyen

    2017-01-01

    Full Text Available Nanotechnology has the ability to target specific areas of the body, controlling the drug release and significantly increasing the bioavailability of active compounds. Organic and inorganic nanoparticles have been developed for drug delivery systems. Many delivery systems are through clinical stages for development and market. Minicell, a nanosized cell generated by bacteria, is a potential particle for drug delivery because of its size, safety, and biodegradability. Minicells produced by bacteria could drive therapeutic agents against cancer, microbial infection, and other diseases by targeting. In addition, minicells generated by lactic acid bacteria being probiotics are more interesting than others because of their benefits like safety, immunological improvement, and biodegradation. This review aims to highlight the stages of development of nanoparticle for drug delivery and discuss their advantages and limitations to clarify minicells as a new opportunity for the development of potential nanoparticle for drug delivery.

  19. Organism-adapted specificity of the allosteric regulation of pyruvate kinase in lactic acid bacteria.

    Directory of Open Access Journals (Sweden)

    Nadine Veith

    Full Text Available Pyruvate kinase (PYK is a critical allosterically regulated enzyme that links glycolysis, the primary energy metabolism, to cellular metabolism. Lactic acid bacteria rely almost exclusively on glycolysis for their energy production under anaerobic conditions, which reinforces the key role of PYK in their metabolism. These organisms are closely related, but have adapted to a huge variety of native environments. They include food-fermenting organisms, important symbionts in the human gut, and antibiotic-resistant pathogens. In contrast to the rather conserved inhibition of PYK by inorganic phosphate, the activation of PYK shows high variability in the type of activating compound between different lactic acid bacteria. System-wide comparative studies of the metabolism of lactic acid bacteria are required to understand the reasons for the diversity of these closely related microorganisms. These require knowledge of the identities of the enzyme modifiers. Here, we predict potential allosteric activators of PYKs from three lactic acid bacteria which are adapted to different native environments. We used protein structure-based molecular modeling and enzyme kinetic modeling to predict and validate potential activators of PYK. Specifically, we compared the electrostatic potential and the binding of phosphate moieties at the allosteric binding sites, and predicted potential allosteric activators by docking. We then made a kinetic model of Lactococcus lactis PYK to relate the activator predictions to the intracellular sugar-phosphate conditions in lactic acid bacteria. This strategy enabled us to predict fructose 1,6-bisphosphate as the sole activator of the Enterococcus faecalis PYK, and to predict that the PYKs from Streptococcus pyogenes and Lactobacillus plantarum show weaker specificity for their allosteric activators, while still having fructose 1,6-bisphosphate play the main activator role in vivo. These differences in the specificity of allosteric

  20. Phenolic Biotransformations during Conversion of Ferulic Acid to Vanillin by Lactic Acid Bacteria

    Directory of Open Access Journals (Sweden)

    Baljinder Kaur

    2013-01-01

    Full Text Available Vanillin is widely used as food additive and as a masking agent in various pharmaceutical formulations. Ferulic acid is an important precursor of vanillin that is available in abundance in cell walls of cereals like wheat, corn, and rice. Phenolic biotransformations can occur during growth of lactic acid bacteria (LAB, and their production can be made feasible using specialized LAB strains that have been reported to produce ferulic acid esterases. The present study aimed at screening a panel of LAB isolates for their ability to release phenolics from agrowaste materials like rice bran and their biotransformation to industrially important compounds such as ferulic acid, 4-ethyl phenol, vanillic acid, vanillin, and vanillyl alcohol. Bacterial isolates were evaluated using ferulic acid esterase, ferulic acid decarboxylase, and vanillin dehydrogenase assays. This work highlights the importance of lactic acid bacteria in phenolic biotransformations for the development of food grade flavours and additives.

  1. Phenolic biotransformations during conversion of ferulic acid to vanillin by lactic acid bacteria.

    Science.gov (United States)

    Kaur, Baljinder; Chakraborty, Debkumar; Kumar, Balvir

    2013-01-01

    Vanillin is widely used as food additive and as a masking agent in various pharmaceutical formulations. Ferulic acid is an important precursor of vanillin that is available in abundance in cell walls of cereals like wheat, corn, and rice. Phenolic biotransformations can occur during growth of lactic acid bacteria (LAB), and their production can be made feasible using specialized LAB strains that have been reported to produce ferulic acid esterases. The present study aimed at screening a panel of LAB isolates for their ability to release phenolics from agrowaste materials like rice bran and their biotransformation to industrially important compounds such as ferulic acid, 4-ethyl phenol, vanillic acid, vanillin, and vanillyl alcohol. Bacterial isolates were evaluated using ferulic acid esterase, ferulic acid decarboxylase, and vanillin dehydrogenase assays. This work highlights the importance of lactic acid bacteria in phenolic biotransformations for the development of food grade flavours and additives.

  2. Phenolic Biotransformations during Conversion of Ferulic Acid to Vanillin by Lactic Acid Bacteria

    Science.gov (United States)

    Kaur, Baljinder; Kumar, Balvir

    2013-01-01

    Vanillin is widely used as food additive and as a masking agent in various pharmaceutical formulations. Ferulic acid is an important precursor of vanillin that is available in abundance in cell walls of cereals like wheat, corn, and rice. Phenolic biotransformations can occur during growth of lactic acid bacteria (LAB), and their production can be made feasible using specialized LAB strains that have been reported to produce ferulic acid esterases. The present study aimed at screening a panel of LAB isolates for their ability to release phenolics from agrowaste materials like rice bran and their biotransformation to industrially important compounds such as ferulic acid, 4-ethyl phenol, vanillic acid, vanillin, and vanillyl alcohol. Bacterial isolates were evaluated using ferulic acid esterase, ferulic acid decarboxylase, and vanillin dehydrogenase assays. This work highlights the importance of lactic acid bacteria in phenolic biotransformations for the development of food grade flavours and additives. PMID:24066293

  3. LACTIC ACID AND ACETIC ACID BACTERIA ISOLATED FROM RED WINE

    Directory of Open Access Journals (Sweden)

    Attila Kántor

    2013-02-01

    Full Text Available The aim of our study was the identification of red wine microbiota during the fermentation process using a classical microbiological method and real-time PCR. The changes in different groups of microorganisms were monitored in total counts of bacteria, Lactobacillus cells and Acetobacter cells. Microbiological parameters were observed during the current collection and processing of wine in 2012. Samples were taken during the fermentation process in wine enterprises and were storaged with different conditions. During this period were examined 4 bottles of wine berween Cabernet Sauvignon and Frankovka modra. The total counts of bacteria ranged from 4.98±0.08 in the wine Cabernet Sauvignon at 4 °C of storage to 5.63±0.13 log CFU.ml-1 in the wine Cabernet Sauvignon at 25 °C of storage. The number of lactobacilli ranged from 2.18±0.10 in the Cabernet Sauvignon at 4 °C to 2.49±0.04 log CFU.ml-1 in the Frankovka modra wine at 25 °C of storage and the number of Acetobacter cells ranged from 4.21±0.04 in the Cabernet Sauvignon at 4 °C of storage to 4.52±0.15 log CFU.ml-1 in Cabernet Sauvignon at 25 °C of storage. The presence and sensitivity of Gram-positive and Gram-negative bacterial species Lactobacillus acidophilus, Lactobacillus crispatus, Lactobacillus salivarius, Acetobacter aceti, Acetobacter pasteurianus and Acetobacter orleaniensis were detected using Real time PCR.

  4. Bacteriocins of lactic acid bacteria: extending the family.

    Science.gov (United States)

    Alvarez-Sieiro, Patricia; Montalbán-López, Manuel; Mu, Dongdong; Kuipers, Oscar P

    2016-04-01

    Lactic acid bacteria (LAB) constitute a heterogeneous group of microorganisms that produce lactic acid as the major product during the fermentation process. LAB are Gram-positive bacteria with great biotechnological potential in the food industry. They can produce bacteriocins, which are proteinaceous antimicrobial molecules with a diverse genetic origin, posttranslationally modified or not, that can help the producer organism to outcompete other bacterial species. In this review, we focus on the various types of bacteriocins that can be found in LAB and the organization and regulation of the gene clusters responsible for their production and biosynthesis, and consider the food applications of the prototype bacteriocins from LAB. Furthermore, we propose a revised classification of bacteriocins that can accommodate the increasing number of classes reported over the last years.

  5. The Efficient Clade: Lactic Acid Bacteria for Industrial Chemical Production.

    Science.gov (United States)

    Sauer, Michael; Russmayer, Hannes; Grabherr, Reingard; Peterbauer, Clemens K; Marx, Hans

    2017-08-01

    Lactic acid bacteria are well known to be beneficial for food production and, as probiotics, they are relevant for many aspects of health. However, their potential as cell factories for the chemical industry is only emerging. Many physiological traits of these microorganisms, evolved for optimal growth in their niche, are also valuable in an industrial context. Here, we illuminate these features and describe why the distinctive adaptation of lactic acid bacteria is particularly useful when developing a microbial process for chemical production from renewable resources. High carbon uptake rates with low biomass formation combined with strictly regulated simple metabolic pathways, leading to a limited number of metabolites, are among the key factors defining their success in both nature and industry. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. DNA fingerprinting of lactic acid bacteria in sauerkraut fermentations.

    Science.gov (United States)

    Plengvidhya, Vethachai; Breidt, Fredrick; Lu, Zhongjing; Fleming, Henry P

    2007-12-01

    Previous studies using traditional biochemical identification methods to study the ecology of commercial sauerkraut fermentations revealed that four species of lactic acid bacteria, Leuconostoc mesenteroides, Lactobacillus plantarum, Pediococcus pentosaceus, and Lactobacillus brevis, were the primary microorganisms in these fermentations. In this study, 686 isolates were collected from four commercial fermentations and analyzed by DNA fingerprinting. The results indicate that the species of lactic acid bacteria present in sauerkraut fermentations are more diverse than previously reported and include Leuconostoc citreum, Leuconostoc argentinum, Lactobacillus paraplantarum, Lactobacillus coryniformis, and Weissella sp. The newly identified species Leuconostoc fallax was also found. Unexpectedly, only two isolates of P. pentosaceus and 15 isolates of L. brevis were recovered during this study. A better understanding of the microbiota may aid in the development of low-salt fermentations, which may have altered microflora and altered sensory characteristics.

  7. Molecular characterization of the phenolic acid metabolism in the lactic acid bacteria Lactobacillus plantarum

    OpenAIRE

    Barthelmebs, Lise; Diviés, Charles; Cavin, Jean-François

    2001-01-01

    International audience; The lactic acid bacteria Lactobacillus plantarum displays substrate-inducible decarboxylase activities on $p$-coumaric, caffeic and ferulic acids. Purification of the $p$-coumaric acid decarboxylase (PDC) was performed. Sequence of the N-terminal part of the PDC led to the cloning of the corresponding pdc gene. Expression of this gene in Escherichia coli revealed that PDC displayed a weak activity on ferulic acid, detectable in vitro in the presence of ammonium sulfate...

  8. PENAMBAHAN BAKTERI ASAM LAKTAT TERENKAPSULASI UNTUK MENEKAN PERTUMBUHAN BAKTERI PATOGEN PADA PROSES PRODUKSI TAPIOKA [Addition of Encapsulated Lactic Acid Bacteria to Suppress the Growth of Pathogenic Bacteria during Tapioca Production

    Directory of Open Access Journals (Sweden)

    Glisina Dwinoor Rembulan

    2015-07-01

    Full Text Available Lactic acid bacteria (LAB produce organic acids and active compounds which can inhibit the growth of pathogenic bacteria. Lactic acid bacteria potentially can be introduced to inhibit pathogenic bacteria in the tapioca production at the extraction stage, especially during the settling process since there is possibility of starch slurry to be contaminated by pathogenic bacteria from water. The objectives of this research were to design a solid starter of LAB through encapsulation by using modified starch includes sour cassava starch, lintnerized cassava starch and nanocrystalline starch, utilize the starter for suppressing the growth of pathogenic bacteria in the production process of tapioca and characterize the functional properties of tapioca. The encapsulation of lactic acid bacteria was conducted by freeze drying at a temperature of -50°C for 48 hours. The viability of LAB after freeze drying with sour cassava starch matrix was 92% of the liquid starter, with lintnerized cassava starch matrix was 93%, while that with nanocrystalline matrix was 96%. After application of the LAB culture during settling process for tapioca extraction and the tapioca was stored at room temperature for 6 months, it was shown that E. coli, Salmonella and Shigella were  detected in the native tapioca starch (without treatment while the starch added with lactic acid bacteria starter was not absent for the pathogenic bacteria. The addition of lactic acid bacteria in extraction process can suppress the growth of pathogenic bacteria in tapioca. The results showed that lintnerized cassava starch matrix is the best matrix because after 6 months it still contained lactic acid bacteria as compared to liquid starter and that encapsulated with other matrixes.

  9. Diversity of lactic acid bacteria isolated from AOC Salers cheese.

    Science.gov (United States)

    Callon, Cécile; Millet, Liliane; Montel, Marie-Christine

    2004-05-01

    The objective of this work was to describe the diversity of lactic acid bacteria in traditional raw milk Salers cheeses at the species and strain levels. The characterization of 381 strains isolated during ripening and various strain collections was investigated using physiological analysis and molecular techniques: Rep-PCR, species and genus specific amplifications and the sequence analysis of 16S rDNA for strain typing and taxonomic identification. The strains belonged to Lactobacillus plantarum, Lactobacillus paracasei, Lactococcus lactis, Lactococcus garviae, Enterococcus faecalis, Enterococcus faecium, Leuconostoc mesenteroides, Leuconostoc pseudomesenteroides, Streptococcus salivarius, Streptococcus millieri, Streptococcus macedonicus and Pediococcus pentosaceus. A wide phenotypic and genomic heterogeneity was observed within the different species (Lactobacillus plantarum, Lactobacillus paracasei and Leuconostoc mesenteroides) according to the origin and the time of ripening. The natural microflora was different from strain collection and each method must be combined to identify and characterize natural microflora. This study revealed the low selectivity of selective media used for the isolation of different groups of lactic acid bacteria except the Facultatively Heterofermentative lactobacilli medium selecting mesophile lactobacilli and SB medium selective for Enterococcus. The study reveals, for the first time, the microbial lactic acid bacteria community of Salers cheese and its diversity. A better knowledge of microbial flora will be useful to improve understanding of sensory quality of cheeses.

  10. Isolation of lactic acid bacteria for its possible use in the fermentation of green algerian olives

    Directory of Open Access Journals (Sweden)

    Nour-Eddine, Karam

    2004-12-01

    Full Text Available This study was undertaken with the aim of obtaining lactic acid bacteria with the ability to ferment olives for possible use as starter cultures. For this reason, 32 isolates of lactic acid bacteria isolated from the spontaneous fermentation of green olives were characterized and identified on the basis of morphological and biochemical criteria. 14 of them were identified as Lactococcus lactis, 11 isolates as Lactobacillus plantarum and 7 isolates as Enterococcus sp. Of the 18 isolates examined for antagonistic activity, 3 isolates of Lactobacillus plantarum and one isolate of Enterococcus sp. were able to give distinct zones of inhibition against 5 indicator strains of lactic acid bacteria isolated in this study. Cell free supernatant of Lactobacillus plantarum OL9 was active against Gram-positive bacteria (Lactobacillus, Enterococcus and Propionibacterium and also against one Gram-negative bacteria strain of spoilage significance (Erwinia.Este estudio se emprendió con el objetivo de obtener bacterias del ácido láctico con capacidad para utilizarse como cultivo iniciador en la fermentación de aceitunas. Por esta razón, 32 cepas de bacterias del ácido láctico procedentes de fermentaciones espontáneas de aceitunas verdes se caracterizaron e identificaron en función de criterios morfológicos y bioquímicos. Catorce cepas se identificaron como Lactococcus lactis, 11 cepas como Lactobacillus plantarum y 7 cepas como Enterococcus sp. De las 18 cepas que se examinaron para detectar actividades antagónicas, se encontró que 3 cepas de Lactobacillus plantarum y una de Enterococcus sp. mostraban zonas de inhibición contra 5 cepas indicadoras de bacterias del ácido láctico aisladas en este estudio. El sobrenadante libre de células Lactobacillus plantarum OL9 fue activo contra diversas bacterias Gram-positivas (Lactobacillus, Enterococcus y Propionibacterium y contra una cepa de bacteria Gram-negativa relacionada con alteraciones (Erwinia.

  11. 40 CFR 798.5500 - Differential growth inhibition of repair proficient and repair deficient bacteria: “Bacterial DNA...

    Science.gov (United States)

    2010-07-01

    ... repair proficient and repair deficient bacteria: âBacterial DNA damage or repair tests.â 798.5500 Section... inhibition of repair proficient and repair deficient bacteria: “Bacterial DNA damage or repair tests.” (a... killing or growth inhibition of repair deficient bacteria in a set of repair proficient and deficient...

  12. Incidence of Bacteriocins Produced by Food-Related Lactic Acid Bacteria Active towards Oral Pathogens

    Directory of Open Access Journals (Sweden)

    Konstantinos Papadimitriou

    2013-02-01

    Full Text Available In the present study we investigated the incidence of bacteriocins produced by 236 lactic acid bacteria (LAB food isolates against pathogenic or opportunistic pathogenic oral bacteria. This set of LAB contained several strains (≥17% producing bacteriocins active against food-related bacteria. Interestingly only Streptococcus macedonicus ACA-DC 198 was able to inhibit the growth of Streptococcus oralis, Streptococcus sanguinis and Streptococcus gordonii, while Lactobacillus fermentum ACA-DC 179 and Lactobacillus plantarun ACA-DC 269 produced bacteriocins solely against Streptococcus oralis. Thus, the percentage of strains that were found to produce bacteriocins against oral bacteria was ~1.3%. The rarity of bacteriocins active against oral LAB pathogens produced by food-related LAB was unexpected given their close phylogenetic relationship. Nevertheless, when tested in inhibition assays, the potency of the bacteriocin(s of S. macedonicus ACA-DC 198 against the three oral streptococci was high. Fourier-transform infrared spectroscopy combined with principal component analysis revealed that exposure of the target cells to the antimicrobial compounds caused major alterations of key cellular constituents. Our findings indicate that bacteriocins produced by food-related LAB against oral LAB may be rare, but deserve further investigation since, when discovered, they can be effective antimicrobials.

  13. Antibacterial activity of hen egg white lysozyme modified by heat and enzymatic treatments against oenological lactic acid bacteria and acetic acid bacteria.

    Science.gov (United States)

    Carrillo, W; García-Ruiz, A; Recio, I; Moreno-Arribas, M V

    2014-10-01

    The antimicrobial activity of heat-denatured and hydrolyzed hen egg white lysozyme against oenological lactic acid and acetic acid bacteria was investigated. The lysozyme was denatured by heating, and native and heat-denatured lysozymes were hydrolyzed by pepsin. The lytic activity against Micrococcus lysodeikticus of heat-denatured lysozyme decreased with the temperature of the heat treatment, whereas the hydrolyzed lysozyme had no enzymatic activity. Heat-denatured and hydrolyzed lysozyme preparations showed antimicrobial activity against acetic acid bacteria. Lysozyme heated at 90°C exerted potent activity against Acetobacter aceti CIAL-106 and Gluconobacter oxydans CIAL-107 with concentrations required to obtain 50% inhibition of growth (IC50) of 0.089 and 0.013 mg/ml, respectively. This preparation also demonstrated activity against Lactobacillus casei CIAL-52 and Oenococcus oeni CIAL-91 (IC50, 1.37 and 0.45 mg/ml, respectively). The two hydrolysates from native and heat-denatured lysozyme were active against O. oeni CIAL-96 (IC50, 2.77 and 0.3 mg/ml, respectively). The results obtained suggest that thermal and enzymatic treatments increase the antibacterial spectrum of hen egg white lysozyme in relation to oenological microorganisms.

  14. Lactic acid bacteria and health: are probiotics safe for human?

    Directory of Open Access Journals (Sweden)

    Izabela Kubiszewska

    2014-11-01

    Full Text Available The effect of Lactobacillus and Bifidobacterium on human health has been examined for many years. Numerous in vivo and in vitro studies have confirmed the beneficial activity of some exogenous lactic acid bacteria in the treatment and prevention of rotaviral infection, antibiotic-associated diarrhea, inflammatory bowel disease and other gastrointestinal disorders. Probiotics support the action of the intestinal microflora and exhibit a favorable modulatory effect on the host’s immune system. However, it should be remembered that relatively harmless lactobacilli can occasionally induce opportunistic infections. Due to reaching almost 20 x 1012 probiotic doses per year which contain live cultures of bacteria, it is essential to monitor the safety aspect of their administration. In recent years, infections caused by Lactobacillus and Bifidobacterium made up 0.05% to 0.4% of cases of endocarditis and bacteremia. In most cases, the infections were caused by endogenous microflora of the host or bacterial strains colonizing the host’s oral cavity. According to a review of cases of infections caused by bacteria of the genus Lactobacillus from 2005 (collected by J.P. Cannot’a, 1.7% of infections have been linked directly with intensive dairy probiotic consumption by patients. Additionally, due to the lack of a precise description of most individuals’ eating habits, the possible effect of probiotics on infection development definitively should not be ruled out. The present paper describes cases of diseases caused by lactic acid bacteria, a potential mechanism for the adverse action of bacteria, and the possible hazard connected with probiotic supplementation for seriously ill and hospitalized patients.

  15. [Lactic acid bacteria and health: are probiotics safe for human?].

    Science.gov (United States)

    Kubiszewska, Izabela; Januszewska, Milena; Rybka, Joanna; Gackowska, Lidia

    2014-11-17

    The effect of Lactobacillus and Bifidobacterium on human health has been examined for many years. Numerous in vivo and in vitro studies have confirmed the beneficial activity of some exogenous lactic acid bacteria in the treatment and prevention of rotaviral infection, antibiotic-associated diarrhea, inflammatory bowel disease and other gastrointestinal disorders. Probiotics support the action of the intestinal microflora and exhibit a favorable modulatory effect on the host's immune system. However, it should be remembered that relatively harmless lactobacilli can occasionally induce opportunistic infections. Due to reaching almost 20x10(12) probiotic doses per year which contain live cultures of bacteria, it is essential to monitor the safety aspect of their administration. In recent years, infections caused by Lactobacillus and Bifidobacterium made up 0.05% to 0.4% of cases of endocarditis and bacteremia. In most cases, the infections were caused by endogenous microflora of the host or bacterial strains colonizing the host's oral cavity. According to a review of cases of infections caused by bacteria of the genus Lactobacillus from 2005 (collected by J.P. Cannot'a), 1.7% of infections have been linked directly with intensive dairy probiotic consumption by patients. Additionally, due to the lack of a precise description of most individuals' eating habits, the possible effect of probiotics on infection development definitively should not be ruled out. The present paper describes cases of diseases caused by lactic acid bacteria, a potential mechanism for the adverse action of bacteria, and the possible hazard connected with probiotic supplementation for seriously ill and hospitalized patients.

  16. Bioprotection of Golden Delicious apples and Iceberg lettuce against foodborne bacterial pathogens by lactic acid bacteria.

    Science.gov (United States)

    Trias, Rosalia; Bañeras, Lluís; Badosa, Esther; Montesinos, Emilio

    2008-03-31

    Lactic acid bacteria were isolated from fresh vegetables and fruit and its ability to inhibit the growth of foodborne human pathogens (Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella typhimurium, and Staphylococcus aureus) was tested using the agar spot assay. Eighteen isolates showed a strong antagonistic capacity and were further characterised and identified using 16S rDNA sequencing and API 50CH. Most of them pertained to Leuconostoc spp. and Lactobacillus plantarum, and a few corresponded to Weissella spp. and Lactococcus lactis. Growth and efficacy of control of foodborne pathogen test bacteria by selected strains were tested in wounded Golden Delicious apples and Iceberg lettuce leaf cuts. The strains grew on the substrates and did not cause negative effects on the general aspect of tissues of apple or lettuce. Treatment of apple wounds and lettuce cuts with the antagonistic strains reduced the cell count of S. typhimurium and E .coli by 1 to 2 log cfu/wound or g, whereas the growth of L. monocytogenes was completely inhibited. Results support the potential use of lactic acid bacteria as bioprotective agents against foodborne human pathogens in ready-to-eat fresh fruit and vegetable products.

  17. Amino acid composition of rumen bacteria and protozoa in cattle.

    Science.gov (United States)

    Sok, M; Ouellet, D R; Firkins, J L; Pellerin, D; Lapierre, H

    2017-07-01

    Because microbial crude protein (MCP) constitutes more than 50% of the protein digested in cattle, its AA composition is needed to adequately estimate AA supply. Our objective was to update the AA contributions of the rumen microbial AA flowing to the duodenum using only studies from cattle, differentiating between fluid-associated bacteria (FAB), particle-associated bacteria (PAB), and protozoa, based on published literature (53, 16, and 18 treatment means were used for each type of microorganism, respectively). In addition, Cys and Met reported concentrations were retained only when an adequate protection of the sulfur groups was performed before the acid hydrolysis. The total AA (or true protein) fraction represented 82.4% of CP in bacteria. For 10 AA, including 4 essential AA, the AA composition differed between protozoa and bacteria. The most noticeable differences were a 45% lower Lys concentration and 40% higher Ala concentration in bacteria than in protozoa. Differences between FAB and PAB were less pronounced than differences between bacteria and protozoa. Assuming 33% FAB, 50% PAB, and 17% of protozoa in MCP duodenal flow, the updated concentrations of AA would decrease supply estimates of Met, Thr, and Val originating from MCP and increase those of Lys and Phe by 5 to 10% compared with those calculated using the FAB composition reported previously. Therefore, inclusion of the contribution of PAB and protozoa to the duodenal MCP flow is needed to adequately estimate AA supply from microbial origin when a factorial method is used to estimate duodenal AA flow. Furthermore, acknowledging the fact that hydrolysis of 1 kg of true microbial protein yields 1.16 kg of free AA substantially increases the estimates of AA supply from MCP. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  18. Recent Developments for Remediating Acidic Mine Waters Using Sulfidogenic Bacteria

    Directory of Open Access Journals (Sweden)

    Ivan Nancucheo

    2017-01-01

    Full Text Available Acidic mine drainage (AMD is regarded as a pollutant and considered as potential source of valuable metals. With diminishing metal resources and ever-increasing demand on industry, recovering AMD metals is a sustainable initiative, despite facing major challenges. AMD refers to effluents draining from abandoned mines and mine wastes usually highly acidic that contain a variety of dissolved metals (Fe, Mn, Cu, Ni, and Zn in much greater concentration than what is found in natural water bodies. There are numerous remediation treatments including chemical (lime treatment or biological methods (aerobic wetlands and compost bioreactors used for metal precipitation and removal from AMD. However, controlled biomineralization and selective recovering of metals using sulfidogenic bacteria are advantageous, reducing costs and environmental risks of sludge disposal. The increased understanding of the microbiology of acid-tolerant sulfidogenic bacteria will lead to the development of novel approaches to AMD treatment. We present and discuss several important recent approaches using low sulfidogenic bioreactors to both remediate and selectively recover metal sulfides from AMD. This work also highlights the efficiency and drawbacks of these types of treatments for metal recovery and points to future research for enhancing the use of novel acidophilic and acid-tolerant sulfidogenic microorganisms in AMD treatment.

  19. Antimicrobial effect of selected lactic acid bacteria against microorganisms with decarboxylase activity

    Directory of Open Access Journals (Sweden)

    Khatantuul Purevdorj

    2017-01-01

    Full Text Available The main purpose of this study was to evaluate the antimicrobial activity of twenty-one bacteriocinogenic lactic acid bacteria (12 strains of Lactococcus lactis subsp. lactis, 4 strains of Lactobacillus gasseri, 3 strains of Lb. helveticus and 2 strains of Lb. acidophilus, LAB against 28 Staphylococcus and 33 Enterococcus strains able to produce tyramine, putrescine, 2-phenylethylamine and cadaverine. The antimicrobial activity of cell-free supernatants (CFS from tested LAB was examined by an agar-well diffusion assay. Nine out of twenty-one strains (33% showed the inhibitory effect on tested enterococci and staphylococci, namely 9 strains of Lactococcus lactis subsp. lactis. The diameters of inhibition zones ranged between 7 mm and 14 mm. The biggest diameter of 14 mm inhibition was obtained with the CFS's from strains CCDM 670 and CCDM 731 on Enterococcus sp. E16 and E28. The cell-free supernatants from Lactococcus lactis subsp. lactis CCDM 71 and from Lactococcus lactis subsp. lactis CCDM 731 displayed the broadest antibacterial activity (52% inhibition of all tested strains. On the other hand, the cell-free supernatants from the screened Lactobacillus strains did not show any inhibitory effect on the tested Staphylococcus and Enterococcus strains. Nowadays, the great attention is given to the antibacterial substances produced by lactic acid bacteria. With the ability to produce a variety of metabolites displaying inhibitory effect, the LAB have great potential in biopreservation of food.

  20. Isolation, enumeration, molecular identification and probiotic potential evaluation of lactic acid bacteria isolated from sheep milk

    Directory of Open Access Journals (Sweden)

    L.B. Acurcio

    2014-06-01

    Full Text Available Lactic acid bacteria species were molecularly identified in milk from Lacaune, Santa Inês and crossbred sheep breeds and their in vitro probiotic potential was evaluated. The species identified were Enterococcus faecium (56.25%, E. durans (31.25% and E. casseliflavus (12.5%. No other lactic acid bacteria species, such as lactobacilli, was identified. Most of the isolated enterococci were resistant to gastric pH (2.0 and to 0.3% oxgall. All tested enterococci were resistant to ceftazidime, oxacillin and streptomycin and sensible to clindamycin, erythromycin and penicillin. The resistance to ciprofloxacin, gentamicin, tetracycline and vancomycin varied among tested species. All tested enterococci strongly inhibited (P<0.05 Escherichia coli and Listeria monocytogenes, moderately inhibited E. faecalis and Staphylococcus aureus and did not inhibit Pseudomonas aeruginosa, Salmonella enterica var. Typhimurium and also one E. durans sample isolated from sheep milk. Four samples of E. faecium, one of E. durans and one of E. casseliflavus presented the best probiotic potential.

  1. Antibacterial efficacy of triple-layered poly(lactic-co-glycolic acid)/nanoapatite/lauric acid guided bone regeneration membrane on periodontal bacteria.

    Science.gov (United States)

    Saarani, Nur Najiha; Jamuna-Thevi, Kalitheerta; Shahab, Neelam; Hermawan, Hendra; Saidin, Syafiqah

    2017-05-31

    A guided bone regeneration (GBR) membrane has been extensively used in the repair and regeneration of damaged periodontal tissues. One of the main challenges of GBR restoration is bacterial colonization on the membrane, constitutes to premature membrane degradation. Therefore, the purpose of this study was to investigate the antibacterial efficacy of triple-layered GBR membrane composed of poly(lactic-co-glycolic acid) (PLGA), nanoapatite (NAp) and lauric acid (LA) with two types of Gram-negative periodontal bacteria, Fusobacterium nucleatum and Porphyromonas gingivalis through a disc diffusion and bacterial count tests. The membranes exhibited a pattern of growth inhibition and killing effect against both bacteria. The increase in LA concentration tended to increase the bactericidal activities which indicated by higher diameter of inhibition zone and higher antibacterial percentage. It is shown that the incorporation of LA into the GBR membrane has retarded the growth and proliferation of Gram-negative periodontal bacteria for the treatment of periodontal disease.

  2. Lactic Acid Bacteria Isolated from the Gastro-Intestinal Tract of Chicken: Potential Use as Probiotic

    Directory of Open Access Journals (Sweden)

    S Harimurti

    2007-05-01

    Full Text Available Lactic acid bacteria have been suggested to have several beneficial effects on human and animals. These bacteria, indigenous to the gastro-intestinal tract, are important in regulating the balance among the desirable and undesirable intestinal microflora and in controlling enteric pathogenic infection in the host. Objectives of this research are to obtain lactic acid bacteria isolates from gastro-intestinal tract of chicken and to screen their ability as a probiotic agent i.e., their antagonistic against pathogenic bacteria, their survival at low pH and high concentration of bile salt. In this research, 74 samples used as sources of bacteria, and among them only 11 samples could be isolated as lactic acid bacteria with the total number of isolates of 61. Based on the preliminary screening i.e., their antagonistic factor against pathogenic bacteria, 20 isolates was further studied. Based on the identification scheme, these isolates belong to three species, i.e., Lactobacillus murinus, Pediococcus acidilactici, and Streptococcus thermophilus. The result showed that most isolates grow well in the media with the initial pH of 5.5, but their growth were retarded when the initial pH 3.5. Only one isolate Streptococcus thermophilus Kp-2 showed its growth at initial pH of 3.5. All isolates did not show any growth at initial pH 2.5, though their viability still high. The result based on the isolates resistance to bile salt showed that most isolates could grow at media with 0.20% of bile salt. Their growth was inhibited with the increasing bile salt concentration. However, few isolates could grow well at media with 1% of bile salt. Based on their characteristics three isolates i.e., Lactobacillus murinus Ar-3, Streptococcus thermophilus Kp-2, and Pediococcus acidilactici Kd-6 were selected as probiotic agents for the continuing research. i.e. production of biomass and its application to chicken production. (Animal Production 9(2: 82-91 (2007 Key Words

  3. Selection of proteolytic bacteria with ability to inhibit Vibrio harveyi during white shrimp (Litopenaeus vannamei cultivation

    Directory of Open Access Journals (Sweden)

    Suntinanalert, P.

    2007-03-01

    Full Text Available Five isolates of bacteria with high proteolytic activity, isolated from water samples of intensive shrimp ponds in southern Thailand, were selected to test for the ability to control the shrimp pathogen Vibrioharveyi. 70 μl of each culture broth were investigated for their ability to inhibit V. harveyi using an agar well diffusion test but only one isolate W3 gave a reasonable sized inhibition zone of 21.62 mm. This zone wassimilar to that of oxolinic acid (2 μg and sulfamethoxazole (25 μg. The W3 isolate was identified as Pseudomonas sp. Shrimp cultivation in aquaria was conducted to investigate the inhibition of V. harveyi bythe isolate W3. The experiment consisted of a treatment of the shrimp culture with an inoculum of the isolate W3 and V. harveyi (biocontrol set, a positive control set (only inoculation of V. harveyi and a negativecontrol set as without inoculation. No mortality was found in the negative control. Shrimp mortality in the biocontrol set (33% was lower than that in the positive control set (40%; however, it showed no significantdifference (p>0.05. The average numbers of V. harveyi over 12 days of the biocontrol set were lower than those in the positive control set by about 1 log cycle although the numbers were not significantly different(p>0.05. The shrimp growth rate at day 32 of cultivation was in order of the biocontrol treatment (10.17% > the negative control treatment (9.44% > the positive control set (9.28%, but no significant difference (p>0.05 was observed among treatments.

  4. Bioconversion Using Lactic Acid Bacteria: Ginsenosides, GABA, and Phenolic Compounds.

    Science.gov (United States)

    Lee, Na-Kyoung; Paik, Hyun-Dong

    2017-05-28

    Lactic acid bacteria (LAB) are used as fermentation starters in vegetable and dairy products and influence the pH and flavors of foods. For many centuries, LAB have been used to manufacture fermented foods; therefore, they are generally regarded as safe. LAB produce various substances, such as lactic acid, β-glucosidase, and β-galactosidase, making them useful as fermentation starters. Existing functional substances have been assessed as fermentation substrates for better component bioavailability or other functions. Representative materials that were bioconverted using LAB have been reported and include minor ginsenosides, γ-aminobutyric acid, equol, aglycones, bioactive isoflavones, genistein, and daidzein, among others. Fermentation mainly involves polyphenol and polysaccharide substrates and is conducted using bacterial strains such as Streptococcus thermophilus, Lactobacillus plantarum, and Bifidobacterium sp. In this review, we summarize recent studies of bioconversion using LAB and discuss future directions for this field.

  5. Phenolic Biotransformations during Conversion of Ferulic Acid to Vanillin by Lactic Acid Bacteria

    OpenAIRE

    Kaur, Baljinder; Chakraborty, Debkumar; Kumar, Balvir

    2013-01-01

    Vanillin is widely used as food additive and as a masking agent in various pharmaceutical formulations. Ferulic acid is an important precursor of vanillin that is available in abundance in cell walls of cereals like wheat, corn, and rice. Phenolic biotransformations can occur during growth of lactic acid bacteria (LAB), and their production can be made feasible using specialized LAB strains that have been reported to produce ferulic acid esterases. The present study aimed at screening a panel...

  6. Food-grade Selection Markers in Lactic Acid Bacteria

    Directory of Open Access Journals (Sweden)

    Song He

    2012-08-01

    Full Text Available Lactic acid bacteria (LAB are generally regarded as safe (GRAS microorganisms and widely used in industry and medicine. We are trying to add additional properties to them by gene engineering. However, the genetically modified bacteria are not acceptable to use in food and medicine due to the presence of antibiotic resistance genes in plasmids. Thus, it is necessary to develop food-grade selection markers. Food-grade markers can be divided into three classes based on their selected characteristics: dominant, complementary and sugar fermentation markers. The developments on these food-grade selection markers were reviewed in order to provide valuable references for the further study. [TAF Prev Med Bull 2012; 11(4.000: 499-510

  7. Development of Mucosal Vaccines Based on Lactic Acid Bacteria

    Science.gov (United States)

    Bermúdez-Humarán, Luis G.; Innocentin, Silvia; Lefèvre, Francois; Chatel, Jean-Marc; Langella, Philippe

    Today, sufficient data are available to support the use of lactic acid bacteria (LAB), notably lactococci and lactobacilli, as delivery vehicles for the development of new mucosal vaccines. These non-pathogenic Gram-positive bacteria have been safely consumed by humans for centuries in fermented foods. They thus constitute an attractive alternative to the attenuated pathogens (most popular live vectors actually studied) which could recover their pathogenic potential and are thus not totally safe for use in humans. This chapter reviews the current research and advances in the use of LAB as live delivery vectors of proteins of interest for the development of new safe mucosal vaccines. The use of LAB as DNA vaccine vehicles to deliver DNA directly to antigen-presenting cells of the immune system is also discussed.

  8. Current taxonomy of phages infecting lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Jennifer eMahony

    2014-01-01

    Full Text Available Phages infecting lactic acid bacteria have been the focus of significant research attention over the past three decades. Through the isolation and characterization of hundreds of phage isolates, it has been possible to classify phages of the dairy starter and adjunct bacteria Lactococus lactis, Streptococcus thermophilus, Leuconostoc spp. and Lactobacillus spp. Among these, phages of L. lactis have been most thoroughly scrutinized and serve as an excellent model system to address issues that arise when attempting taxonomic classification of phages infecting other LAB species. Here, we present an overview of the current taxonomy of phages infecting LAB genera of industrial significance, the methods employed in these taxonomic efforts and how these may be employed for the taxonomy of phages of currently underrepresented and emerging phage species.

  9. Analysis of proteins responsive to acetic acid in Acetobacter: molecular mechanisms conferring acetic acid resistance in acetic acid bacteria.

    Science.gov (United States)

    Nakano, Shigeru; Fukaya, Masahiro

    2008-06-30

    Acetic acid bacteria are used for industrial vinegar production because of their remarkable ability to oxidize ethanol and high resistance to acetic acid. Although several molecular machineries responsible for acetic acid resistance in acetic acid bacteria have been reported, the entire mechanism that confers acetic acid resistance has not been completely understood. One of the promising methods to elucidate the entire mechanism is global analysis of proteins responsive to acetic acid by two-dimensional gel electrophoresis. Recently, two proteins whose production was greatly enhanced by acetic acid in Acetobacter aceti were identified to be aconitase and a putative ABC-transporter, respectively; furthermore, overexpression or disruption of the genes encoding these proteins affected acetic acid resistance in A. aceti, indicating that these proteins are involved in acetic acid resistance. Overexpression of each gene increased acetic acid resistance in Acetobacter, which resulted in an improvement in the productivity of acetic acid fermentation. Taken together, the results of the proteomic analysis and those of previous studies indicate that acetic acid resistance in acetic acid bacteria is conferred by several mechanisms. These findings also provide a clue to breed a strain having high resistance to acetic acid for vinegar fermentation.

  10. Selective inhibition of Erwinia amylovora by the herbicidally active germination-arrest factor (GAF) produced by Pseudomonas bacteria.

    Science.gov (United States)

    Halgren, A; Azevedo, M; Mills, D; Armstrong, D; Thimmaiah, M; McPhail, K; Banowetz, G

    2011-10-01

     The germination-arrest factor (GAF) produced by Pseudomonas fluorescens WH6, and identified as 4-formylaminooxyvinylglycine, specifically inhibits the germination of a wide range of grassy weeds. This study was undertaken to determine whether GAF has antimicrobial activity in addition to its inhibitory effects on grass seed germination. Culture filtrate from Ps. fluorescens WH6 had little or no effect on 17 species of bacteria grown in Petri dish lawns, but the in vitro growth of Erwinia amylovora, the causal agent of the disease of orchard crops known as fire blight, was strongly inhibited by the filtrate. The anti-Erwinia activity of WH6 culture filtrate was shown to be due to its GAF content, and a commercially available oxyvinylglycine, 4-aminoethoxyvinylglycine (AVG), exhibited anti-Erwinia activity similar to that of GAF. The effects of GAF on Erwinia were reversed by particular amino acids. The biological properties of GAF include a rather specific antimicrobial activity against Erw. amylovora. This may be a general property of oxyvinylglycines as AVG exhibited similar activity. The ability of particular amino acids to reverse GAF inhibition is consistent with a potential effect of this compound on the activity of aminotransferases. The results presented here demonstrate a novel antimicrobial activity of oxyvinylglycines and suggest that GAF and/or GAF-producing bacteria may have potential for the control of fire blight. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology. No claim to US Government works.

  11. Screening of probiotic lactic acid bacteria from Thai fermented foods for human.

    Directory of Open Access Journals (Sweden)

    Kantachote, D.

    2004-09-01

    Full Text Available Total of 327 strains of lactic acid bacteria were isolated from 179 samples of various Thai fermented foods. The strains were investigated for their probiotic properties based on stability in bile salt (0.15% and high acidity (pH 2, 3 and 4. Moreover, utilization of protein or fat or starch, growth in the absence of vitamin B12 and growth under both aerobic and anaerobic conditions with no significant difference were also considered. According to the above criteria, 67 strains were selected for antibiotics sensitivity test. The selected strains were susceptible to following antibiotics: ampicillin, cephalothin, cefoperazone, tetracycline andchloramphenicol; however the strains were resistant to vancomycin, kanamycin, streptomycin, norfloxacin and polymyxin B. Using agar spot method, only 5 strains were able to inhibit 13 strains of manifest by a bacteria indicator as clear zone greater than 10 mm. A further investigation using co-culture technique showed inhibition of the tested organisms was between 80 and 100 percent. The strains grew under media of MRS and SPY2 (no materials from animal over 36 hours with no significant difference. The strains were investigated for survival in condition of high acidity within 3 hours. It was found that at pH 4 almost 100% were maintained but at pH 2 and 3 the survival reduced approximately 1 log cycle. The strain LA71 which showed the highest survival was identified as Lactobacillus plantarum.

  12. Commercial probiotic bacteria and prebiotic carbohydrates: a fundamental study on prebiotics uptake, antimicrobials production and inhibition of pathogens.

    Science.gov (United States)

    Cruz-Guerrero, Alma; Hernández-Sánchez, Humberto; Rodríguez-Serrano, Gabriela; Gómez-Ruiz, Lorena; García-Garibay, Mariano; Figueroa-González, Ivonne

    2014-08-01

    Probiotics and prebiotics are among the most important functional food ingredients worldwide. The proven benefits of such ingredients to human health have encouraged the development of functional foods containing both probiotics and prebiotics. In this work, the production of antimicrobial compounds coupled to the uptake of commercial prebiotics by probiotic bacteria was investigated. The probiotic bacteria studied were able to take up commercial prebiotic carbohydrates to the same or higher extent than that observed for lactose (control carbohydrate). The growth of probiotic bacteria was coupled to the production of antimicrobials such as short-chain fatty acids (SCFA), H2 O2 and bacteriocins. A higher production of antimicrobial compounds was recorded with Oligomate 55® compared with Regulact® and Frutafit® (3-5 and 10-115 times higher SCFA and H2 O2 production, respectively). The probiotic bacteria grown with Oligomate 55® also produced bacteriocins and other non-identified antimicrobial compounds. The antimicrobials produced by the probiotic bacteria inhibited up to 50% the growth of model pathogens such as Escherichia coli, Listeria innocua and Micrococcus luteus compared with control cultures. The results here obtained are useful for the adequate selection of probiotic/prebiotics pairs and therefore in the development of efficient functional foods. © 2013 Society of Chemical Industry.

  13. Analyses of Dynamics in Dairy Products and Identification of Lactic Acid Bacteria Population by Molecular Methods

    OpenAIRE

    Aytül Sofu

    2017-01-01

    Lactic acid bacteria (LAB) with different ecological niches are widely seen in fermented meat, vegetables, dairy products and cereals as well as in fermented beverages. Lactic acid bacteria are the most important group of bacteria in dairy industry due to their probiotic characteristics and fermentation agents as starter culture. In the taxonomy of the lactic acid bacteria; by means of rep-PCR, which is the analysis of repetitive sequences that are based on 16S ribosomal RNA (rRNA) gene seque...

  14. Endophytic Fungi Associated With Turmeric (Curcuma longa L. Can Inhibit Histamine-Forming Bacteria in Fish

    Directory of Open Access Journals (Sweden)

    Eris Septiana

    2017-01-01

    Full Text Available Turmeric (Curcuma longa L. is a medicinal plant that is commonly used as spice and preservative. Many types of endophytic fungi have been reported as being associated with medicinal plants and able to synthesize secondary metabolites. In this study, endophytic fungi were isolated from all plant parts of turmeric plants. Identification of the endophytic fungi was done using morphological characteristics and sequencing of the internal transcribed spacer (ITS region of ribosomal DNA. The dual culture method was used for screening antibacterial activity of the endophytic fungi against Morganella morganii, a common histamine-producing bacteria. The disc diffusion method was used to test the ability of water fractions of selected endophytic fungi to inhibit M. morganii growth. Two-dimensional thin layer chromatography was used to determine the fungal extract inhibition activity on histamine formation. In total, 11 endophytic fungi were successfully isolated and identified as Arthrobotrys foliicola, Cochliobolus kusanoi, Daldinia eschscholzii, Fusarium oxysporum, Fusarium proliferatum, Fusarium solani, Fusarium verticillioides, Phanerochaete chrysosporium, and Phaeosphaeria ammophilae. Five isolates showed inhibition activity against M. morganii in the dual culture tests. Based on the disc diffusion assay, A. foliicola and F. verticillioides inhibited the growth of M. morganii as a histamine-producing bacteria, and inhibiting histamine formation in fish. The best effects in inhibiting growth of the histamine-producing bacteria and histamine formation inhibition in fish were produced with F. verticillioides water fraction at 0°C incubation.

  15. Fermentation of aqueous plant seed extracts by lactic acid bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Schafner, D.W.; Beuchat, R.L.

    1986-05-01

    The effects of lactic acid bacterial fermentation on chemical and physical changes in aqueous extracts of cowpea (Vigna unguiculata), peanut (Arachis hypogea), soybean (Glycine max), and sorghum (Sorghum vulgare) were studied. The bacteria investigated were Lactobacillus helveticus, L. delbrueckii, L. casei, L. bulgaricus, L. acidophilus, and Streptococcus thermophilus. Organisms were inoculated individually into all of the seed extracts; L. bulgaricus and S. thermophilus were also evaluated together as inocula for fermenting the legume extracts. During fermentation, bacterial population and changes in titratable acidity, pH, viscosity, and color were measured over a 72 h period at 37 degrees C. Maximum bacterial populations, titratable acidity, pH, and viscosity varied depending upon the type of extract and bacterial strain. The maximum population of each organism was influenced by fermentable carbohydrates, which, in turn, influenced acid production and change in pH. Change in viscosity was correlated with the amount of protein and titratable acidity of products. Color was affected by pasteurization treatment and fermentation as well as the source of extract. In the extracts inoculated simultaneously with L. bulgaricus and S. thermophilus, a synergistic effect resulted in increased bacterial populations, titratable acidity, and viscosity, and decreased pH in all the legume extracts when compared to the extracts fermented with either of these organisms individually. Fermented extracts offer potential as substitutes for cultured dairy products. 24 references.

  16. Metabolic strategies of beer spoilage lactic acid bacteria in beer.

    Science.gov (United States)

    Geissler, Andreas J; Behr, Jürgen; von Kamp, Kristina; Vogel, Rudi F

    2016-01-04

    Beer contains only limited amounts of readily fermentable carbohydrates and amino acids. Beer spoilage lactic acid bacteria (LAB) have to come up with metabolic strategies in order to deal with selective nutrient content, high energy demand of hop tolerance mechanisms and a low pH. The metabolism of 26 LAB strains of 6 species and varying spoilage potentialwas investigated in order to define and compare their metabolic capabilities using multivariate statistics and outline possible metabolic strategies. Metabolic capabilities of beer spoilage LAB regarding carbohydrate and amino acids did not correlate with spoilage potential, but with fermentation type (heterofermentative/homofermentative) and species. A shift to mixed acid fermentation by homofermentative (hof) Pediococcus claussenii and Lactobacillus backii was observed as a specific feature of their growth in beer. For heterofermentative (hef) LAB a mostly versatile carbohydrate metabolism could be demonstrated, supplementing the known relevance of organic acids for their growth in beer. For hef LAB a distinct amino acid metabolism, resulting in biogenic amine production, was observed, presumably contributing to energy supply and pH homeostasis.

  17. Volatile Compounds and Lactic Acid Bacteria in Spontaneous Fermented Sourdough

    International Nuclear Information System (INIS)

    Kam, W.Y.; Aida, W.M.W.; Sahilah, A.M.; Maskat, M.Y.

    2011-01-01

    The aim of this study is to identify the predominating lactic acid bacteria (LAB) in a spontaneous fermented wheat sourdough. At the same time, an investigation towards volatile compounds that were produced was also carried out. Lactobacillus plantarum has been identified as the dominant species of lactobacilli with characters of a facultative heterofermentative strain. The generated volatile compounds that were produced during spontaneous fermentation were isolated by solvent extraction method, analysed by gas chromatography (GC), and identified by mass spectrophotometer (MS). Butyric acid has been found to be the main volatile compound with relative abundance of 6.75 % and acetic acid at relative abundance of 3.60 %. Esters that were formed at relatively low amount were butyl formate (1.23 %) and cis 3 hexenyl propionate (0.05 %). Butanol was also found at low amount with relative abundance of 0.60 %. The carbohydrate metabolism of Lactobacillus plantarum may contributed to the production of acetic acid in this study via further catabolism activity on lactic acid that was produced. However, butyric acid was not the major product via fermentation by LAB but mostly carried out by the genus Clostridium via carbohydrate metabolism which needs further investigation. (author)

  18. Inhibition of Fungal Pathogens across Genotypes and Temperatures by Amphibian Skin Bacteria

    Directory of Open Access Journals (Sweden)

    Carly R. Muletz-Wolz

    2017-08-01

    Full Text Available Symbiotic bacteria may dampen the impacts of infectious diseases on hosts by inhibiting pathogen growth. However, our understanding of the generality of pathogen inhibition by different bacterial taxa across pathogen genotypes and environmental conditions is limited. Bacterial inhibitory properties are of particular interest for the amphibian-killing fungal pathogens (Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans, for which probiotic applications as conservation strategies have been proposed. We quantified the inhibition strength of five putatively B. dendrobatidis-inhibitory bacteria isolated from woodland salamander skin against six Batrachochytrium genotypes at two temperatures (12 and 18°C. We selected six genotypes from across the Batrachochytrium phylogeny: B. salamandrivorans, B. dendrobatidis-Brazil and four genotypes of the B. dendrobatidis Global Panzootic Lineage (GPL1: JEL647, JEL404; GPL2: SRS810, JEL423. We performed 96-well plate challenge assays in a full factorial design. We detected a Batrachochytrium genotype by temperature interaction on bacterial inhibition score for all bacteria, indicating that bacteria vary in ability to inhibit Batrachochytrium depending on pathogen genotype and temperature. Acinetobacter rhizosphaerae moderately inhibited B. salamandrivorans at both temperatures (μ = 46–53%, but not any B. dendrobatidis genotypes. Chryseobacterium sp. inhibited three Batrachochytrium genotypes at both temperatures (μ = 5–71%. Pseudomonas sp. strain 1 inhibited all Batrachochytrium genotypes at 12°C and four Batrachochytrium genotypes at 18°C (μ = 5–100%. Pseudomonas sp. strain 2 and Stenotrophomonas sp. moderately to strongly inhibited all six Batrachochytrium genotypes at both temperatures (μ = 57–100%. All bacteria consistently inhibited B. salamandrivorans. Using cluster analysis of inhibition scores, we found that more closely related Batrachochytrium genotypes grouped together

  19. Lactic acid bacteria isolated from yak milk show probiotic potential.

    Science.gov (United States)

    Kaur, Manpreet; Singh, Harjodh; Jangra, Manoj; Kaur, Lakhwinder; Jaswal, Pallavi; Dureja, Chetna; Nandanwar, Hemraj; Chaudhuri, Saumya Ray; Raje, Manoj; Mishra, Sunita; Pinnaka, Anil Kumar

    2017-10-01

    Probiotic industries strive for new, efficient and promising probiotic strains that impart a positive impact on consumer health. Challenges are persisting in isolation, screening, and selection of the new indigenous probiotic strains. In the present research, we explored the probiotic potential of 17 lactic acid bacteria isolated from Yak milk in a series of in vitro tests. We also demonstrated their health benefits, i.e., cholesterol degradation, lactose digestion, antimicrobial activity, antioxidant, and anticancer activities. Principal component analysis revealed that more than 50% of the strains fulfilled the examined criteria, e.g., survival in acidic pH, bile concentrations, and adherent property. Approximately all the strains produced antimicrobial substances against the maximum number of tested strains including clinical strains. Most strains degraded cholesterol in comparison to the reference probiotic strain whereas strain Yc showed 1.5 times higher the degradation efficiency of the control strain. Lan4 strain exhibited remarkable anticancer activity and induced the maximum apoptosis (87%) in the Hela cells and was non-toxic to the non-cancerous HEK293 cells. Around ten strains showed positive lactose digestion. Overall, this can be concluded that selected lactic acid bacteria revealed excellent probiotic properties along with desirable health benefits. These strains need to be further investigated in details for their application in the development of novel probiotic preparations for the improvement of public health.

  20. Corrosion inhibition of aqueous solutions of inorganic mineral acids

    Energy Technology Data Exchange (ETDEWEB)

    Stanford, J.R.

    1971-06-15

    A particularly corrosive use of mineral acids is the employment of 15% solutions and, in some instances, even more concentrated solutions of hydrochloric acid in oil well acidizing applications. It has been found that aqueous solutions of inorganic mineral acids, particularly hydrochloric acid solutions, may be inhibited against their corrosive tendencies toward ferrous metals by adding novel compositions of the invention whereby inhibited mineral acid aqueous solutions are provided. In its simplest embodiment the invention comprises using in combination the Mannich reaction products of a hydroabietyl amine, formaldehyde, and certain aliphatic aldehydes in combination with an acetylenic alcohol which contains from 3 to 12 carbon atoms. (7 claims)

  1. Functional fermented whey-based beverage using lactic acid bacteria.

    Science.gov (United States)

    Pescuma, Micaela; Hébert, Elvira María; Mozzi, Fernanda; de Valdez, Graciela Font

    2010-06-30

    Whey protein concentrate (WPC) is employed as functional food ingredient because of its nutritional value and emulsifying properties. However, the major whey protein beta-lactoglobulin (BLG) is the main cause of milk allergy. The aim of this study was to formulate a fermented whey beverage using selected lactic acid bacteria and WPC35 (WPC containing 35% of proteins) to obtain a fermented product with low lactose and BLG contents and high essential amino acid concentration. Cell viability, lactose consumption, lactic acid production, proteolytic activity, amino acid release and BLG degradation by the selected strains Lactobacillus acidophilus CRL 636, Lactobacillus delbrueckii subsp. bulgaricus CRL 656 and Streptococcus thermophilus CRL 804, as single or mixed (SLaB) cultures were evaluated in WPC35 (10%, w/v) incubated at 37 degrees C for 24h. Then, the fermented WPC35 was mixed with peach juice and calcium lactate (2%, w/v) and stored at 10 degrees C for 28 days. During fermentation, single cultures grew 1.7-3.1 log CFU/ml and produced 25.1-95.0 mmol/l of lactic acid as consequence of lactose consumption (14.0-41.8 mmol/l) after 12h fermentation. L. delbrueckii subsp. bulgaricus CRL 656 was the most proteolytic strain (626 microg/ml Leu) and released the branched-chain essential amino acids Leu (16 microg/ml), Ile (27 microg/ml) and Val (43 microg/ml). All strains were able to degrade BLG in a range of 41-85% after 12h incubation. The starter culture SLaB grew 3.0 log CFU/ml, showed marked pH reduction, produced 122.0 mmol/l of lactic acid, displayed high proteolytic activity (484 microg/ml Leu) releasing Leu (13 microg/ml), Ile (18 microg/ml) and Val (35 microg/ml), and hydrolyzed 92% of BLG. The addition of calcium lactate to WPC35 maintained the drink pH stable during shelf life; no contamination was detected during this period. After 28 days, a decrease in cell viability of all strains was observed being more pronounced for L. delbrueckii subsp. bulgaricus

  2. Acetic acid bacteria in fermented foods and beverages.

    Science.gov (United States)

    De Roos, Jonas; De Vuyst, Luc

    2018-02-01

    Although acetic acid bacteria (AAB) are commonly found in spontaneous or backslopped fermented foods and beverages, rather limited knowledge about their occurrence and functional role in natural food fermentation ecosystems is available. Not only is their cultivation, isolation, and identification difficult, their cells are often present in a viable but not culturable state. Yet, they are promising starter cultures either to better control known food fermentation processes or to produce novel fermented foods and beverages. This review summarizes the most recent findings on the occurrence and functional role of AAB in natural food fermentation processes such as lambic beer, water kefir, kombucha, and cocoa. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Overview on mechanisms of acetic acid resistance in acetic acid bacteria.

    Science.gov (United States)

    Wang, Bin; Shao, Yanchun; Chen, Fusheng

    2015-02-01

    Acetic acid bacteria (AAB) are a group of gram-negative or gram-variable bacteria which possess an obligate aerobic property with oxygen as the terminal electron acceptor, meanwhile transform ethanol and sugar to corresponding aldehydes, ketones and organic acids. Since the first genus Acetobacter of AAB was established in 1898, 16 AAB genera have been recorded so far. As the main producer of a world-wide condiment, vinegar, AAB have evolved an elegant adaptive system that enables them to survive and produce a high concentration of acetic acid. Some researches and reviews focused on mechanisms of acid resistance in enteric bacteria and made the mechanisms thoroughly understood, while a few investigations did in AAB. As the related technologies with proteome, transcriptome and genome were rapidly developed and applied to AAB research, some plausible mechanisms conferring acetic acid resistance in some AAB strains have been published. In this review, the related mechanisms of AAB against acetic acid with acetic acid assimilation, transportation systems, cell morphology and membrane compositions, adaptation response, and fermentation conditions will be described. Finally, a framework for future research for anti-acid AAB will be provided.

  4. Diversity of lactic acid bacteria of the bioethanol process

    Directory of Open Access Journals (Sweden)

    Azevedo Vasco

    2010-11-01

    Full Text Available Abstract Background Bacteria may compete with yeast for nutrients during bioethanol production process, potentially causing economic losses. This is the first study aiming at the quantification and identification of Lactic Acid Bacteria (LAB present in the bioethanol industrial processes in different distilleries of Brazil. Results A total of 489 LAB isolates were obtained from four distilleries in 2007 and 2008. The abundance of LAB in the fermentation tanks varied between 6.0 × 105 and 8.9 × 108 CFUs/mL. Crude sugar cane juice contained 7.4 × 107 to 6.0 × 108 LAB CFUs. Most of the LAB isolates belonged to the genus Lactobacillus according to rRNA operon enzyme restriction profiles. A variety of Lactobacillus species occurred throughout the bioethanol process, but the most frequently found species towards the end of the harvest season were L. fermentum and L. vini. The different rep-PCR patterns indicate the co-occurrence of distinct populations of the species L. fermentum and L. vini, suggesting a great intraspecific diversity. Representative isolates of both species had the ability to grow in medium containing up to 10% ethanol, suggesting selection of ethanol tolerant bacteria throughout the process. Conclusions This study served as a first survey of the LAB diversity in the bioethanol process in Brazil. The abundance and diversity of LAB suggest that they have a significant impact in the bioethanol process.

  5. Antagonism Between Osmophilic Lactic Acid Bacteria and Yeasts in Brine Fermentation of Soy Sauce

    OpenAIRE

    Noda, Fumio; Hayashi, Kazuya; Mizunuma, Takeji

    1980-01-01

    Brine fermentation by osmophilic lactic acid bacteria and yeasts for long periods of time is essential to produce a good quality of shoyu (Japanese fermented soy sauce). It is well known that lactic acid fermentation by osmophilic lactic acid bacteria results in the depression of alcoholic fermentation by osmophilic yeasts, but the nature of the interaction between osmophilic lactic acid bacteria and yeasts in brine fermentation of shoyu has not been revealed. The inhibitory effect of osmophi...

  6. Detoxification of cancerogenic compounds by lactic acid bacteria strains.

    Science.gov (United States)

    Lili, Zhao; Junyan, Wei; Hongfei, Zhao; Baoqing, Zhu; Bolin, Zhang

    2017-10-20

    Carcinogens in food are an important issue that threat people's health right now. Lactic acid bacteria (LAB) strains as well-known probiotics have shown numerous perspectives in being used as a good food additive to confront cancerogenic compounds in recent years. Some LAB strains can remove cancerogenic compounds from medium environment via direct physical binding and avoid re-pollution of poisonous secondary metabolites which are generated from degradation of cancerogenic compounds. This article presents a whole overview of the physical-binding of LAB strains to such common cancerogenic compounds existed in food and feed environments as mycotoxins, polycyclic aromatic hydrocarbons (PAHs), heterocyclic amines (HAs) and pthalic acid esters (PAEs).In most cases, summaries of these published researches show that the binding of LAB strains to cancerogenic compounds is a physical process. Binding sites generally take place in cell wall, and peptidoglycan from LAB cells is the chief binding site. The adsorption of lactic acid bacteria to cancerogenic compounds is strain-specific. Specially, the strains from the two genera Lactobacillus and Bifidobacterium show a better potential in binding cancerogenic compounds. Moreover, we firstly used molecular dynamic computer model as a highly potential tool to simulate the binding behavior of peptidoglycan from Lactobacillus acidophilus to DBP, one of pthalic acid esters with genetic toxicity. It was seen that the theoretical data were quite consistent with the experimental results in terms of the ability of this bacterium to bind DBP. Also, the toxicity reduction of cancerogenic compounds by LAB strains could be achieved either in gastrointestinal model or animal tests and clinical researches as well. In conclusion, carefully selected LAB strains should be a good solution as one of safety strategies to reduce potential risk of cancerogenic compounds from food-based products.

  7. Inhibition of multiplication of herpes simplex virus by caffeic acid.

    Science.gov (United States)

    Ikeda, Keiko; Tsujimoto, Kazuko; Uozaki, Misao; Nishide, Mitsunori; Suzuki, Yukiko; Koyama, A Hajime; Yamasaki, Hisashi

    2011-10-01

    Hot water extracts of coffee grinds and commercial instant coffee solutions have been shown to exhibit marked antiviral and virucidal activities against herpes simplex virus type 1 (HSV-1). Specifically, it has been shown that caffeine and N-methyl-pyridinium formate inhibit the multiplication of HSV-1 in HEp-2 cells. The present study examined the virological properties and the antiviral activity of caffeic acid against HSV-1. Caffeic acid inhibited the multiplication of HSV-1 in vitro, while chlorogenic acid, a caffeic acid ester with quinic acid, did not. These reagents did not have a direct virucidal effect. The one-step growth curve of HSV-1 showed that the addition of caffeic acid at 8 h post infection (h p.i.) did not significantly affect the formation of progeny viruses. An analysis of the influence of the time of caffeic acid addition, revealed that addition at an early time post infection remarkably inhibited the formation of progeny infectious virus in the infected cells, but its addition after 6 h p.i. (i.e., the time of the completion of viral genome replication) did not efficiently inhibit this process. These results indicate that caffeic acid inhibits HSV-1 multiplication mainly before the completion of viral DNA replication, but not thereafter. Although caffeic acid showed some cytotoxicity by prolonged incubation, the observed antiviral activity is likely not the secondary result of the cytotoxic effect of the reagent, because the inhibition of the virus multiplication was observed before appearance of the notable cytotoxicity.

  8. Acetic acid production from food wastes using yeast and acetic acid bacteria micro-aerobic fermentation.

    Science.gov (United States)

    Li, Yang; He, Dongwei; Niu, Dongjie; Zhao, Youcai

    2015-05-01

    In this study, yeast and acetic acid bacteria strains were adopted to enhance the ethanol-type fermentation resulting to a volatile fatty acids yield of 30.22 g/L, and improve acetic acid production to 25.88 g/L, with food wastes as substrate. In contrast, only 12.81 g/L acetic acid can be obtained in the absence of strains. The parameters such as pH, oxidation reduction potential and volatile fatty acids were tested and the microbial diversity of different strains and activity of hydrolytic ferment were investigated to reveal the mechanism. The optimum pH and oxidation reduction potential for the acetic acid production were determined to be at 3.0-3.5 and -500 mV, respectively. Yeast can convert organic matters into ethanol, which is used by acetic acid bacteria to convert the organic wastes into acetic acid. The acetic acid thus obtained from food wastes micro-aerobic fermentation liquid could be extracted by distillation to get high-pure acetic acid.

  9. In vitro growth inhibition of mastitis causing bacteria by phenolics and metal chelators

    Energy Technology Data Exchange (ETDEWEB)

    Chew, B.P.; Tjoelker, L.W.; Tanaka, T.S.

    1985-11-01

    Antimicrobial activities of three phenolic compounds and four metal chelators were tested at 0, 250, 500, and 1000 ppm in vitro against four major mastitis-causing bacteria, Streptococcus agalactiae, Staphylococcus aureus, Klebsiella pnuemoniae, and Escherichia coli. Overall, butylated hydroxyanisole and tert-butylhydroquinone showed the greatest antimicrobial activity. These phenolics were bactericidal at 250 to 500 ppm against all four bacteria tested. The butylated hydroxytoluene was bactericidal against the gram-positive bacteria but was ineffective against the coliforms. At 250 ppm, disodium ethylenediaminetetraacetic acid was bactericidal against the gram-positive bacteria but much less effective against the gram-negatives. However, diethylene-triaminepentaacetic acid was more growth inhibitory than ethylenediaminetetraacetic acid against the gram-negative bacteria and especially against Escherichia coli. All other compounds were generally much less effective or ineffective against all four microorganisms. Therefore, butylated hydroxyanisole, butylated hydroxytoluene, tert-butylhydroquinone, ethylenediaminetetraacetic acid, and diethylenetriaminepentaacetic acid may have practical implications in the prevention or treatment of bovine mastitis.

  10. Population dynamics of mixed cultures of yeast and lactic acid bacteria in cider conditions

    Directory of Open Access Journals (Sweden)

    Leila Roseli Dierings

    2013-10-01

    Full Text Available The objective of this work was to study the malolactic bioconversion in low acidity cider, according Brazilian conditions. The apple must was inoculated with Saccharomyces cerevisiae or S. cerevisiae with Oenococcus oeni. The control contained the indigenous microorganisms. Fermentation assays were carried out with clarified apple must from the Gala variety. At the beginning of fermentation, there was a fast growth of the non-Saccharomyces yeast population. Competitive inhibition occurred in all the assays, either with inoculated or indigenous populations of the yeast. The lactic acid bacteria count was ca. 1.41·10²CFU/mL at the beginning and 10(6CFU/mL after yeast cells autolysis. The lactic bacteria O. oeni reached the highest population (10(7CFU/mL when added to the apple must after the decline of the yeast. The malic acid was totally consumed during the alcoholic fermentation period (80.0 to 95.5 % and lactic acid was still synthesized during the 35 days of malolactic fermentation. These results could be important in order to achieve a high quality brut, or sec cider obtained from the dessert apple must.

  11. The use of lactic acid bacteria to reduce mercury bioaccessibility.

    Science.gov (United States)

    Jadán-Piedra, C; Alcántara, C; Monedero, V; Zúñiga, M; Vélez, D; Devesa, V

    2017-08-01

    Mercury in food is present in either inorganic [Hg(II)] or methylmercury (CH 3 Hg) form. Intestinal absorption of mercury is influenced by interactions with other food components. The use of dietary components to reduce mercury bioavailability has been previously proposed. The aim of this work is to explore the use of lactic acid bacteria to reduce the amount of mercury solubilized after gastrointestinal digestion and available for absorption (bioaccessibility). Ten strains were tested by addition to aqueous solutions containing Hg(II) or CH 3 Hg, or to food samples, and submission of the mixtures to gastrointestinal digestion. All of the strains assayed reduce the soluble fraction from standards of mercury species under gastrointestinal digestion conditions (72-98%). However their effectiveness is lower in food, and reductions in bioaccessibility are only observed with mushrooms (⩽68%). It is hypothesized that bioaccessible mercury in seafood forms part of complexes that do not interact with lactic acid bacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Identification and quantification of antifungal compounds produced by lactic acid bacteria and propionibacteria.

    Science.gov (United States)

    Le Lay, Céline; Coton, Emmanuel; Le Blay, Gwenaëlle; Chobert, Jean-Marc; Haertlé, Thomas; Choiset, Yvan; Van Long, Nicolas Nguyen; Meslet-Cladière, Laurence; Mounier, Jérôme

    2016-12-19

    Fungal growth in bakery products represents the most frequent cause of spoilage and leads to economic losses for industrials and consumers. Bacteria, such as lactic acid bacteria and propionibacteria, are commonly known to play an active role in preservation of fermented food, producing a large range of antifungal metabolites. In a previous study (Le Lay et al., 2016), an extensive screening performed both in vitro and in situ allowed for the selection of bacteria exhibiting an antifungal activity. In the present study, active supernatants against Penicillium corylophilum and Aspergillus niger were analyzed to identify and quantify the antifungal compounds associated with the observed activity. Supernatant treatments (pH neutralization, heating and addition of proteinase K) suggested that organic acids played the most important role in the antifungal activity of each tested supernatant. Different methods (HPLC, mass spectrometry, colorimetric and enzymatic assays) were then applied to analyze the supernatants and it was shown that the main antifungal compounds corresponded to lactic, acetic and propionic acids, ethanol and hydrogen peroxide, as well as other compounds present at low levels such as phenyllactic, hydroxyphenyllactic, azelaic and caproic acids. Based on these results, various combinations of the identified compounds were used to evaluate their effect on conidial germination and fungal growth of P. corylophilum and Eurotium repens. Some combinations presented the same activity than the bacterial culture supernatant thus confirming the involvement of the identified molecules in the antifungal activity. The obtained results suggested that acetic acid was mainly responsible for the antifungal activity against P. corylophilum and played an important role in E. repens inhibition. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. [Screening and functional properties of cholesterol-degrading lactic acid bacteria from Jiangshui].

    Science.gov (United States)

    Li, Xueping; Li, Jianhong; Li, Minquan; Meng, Xiangang

    2015-08-04

    We intended to obtain and characterize lactic acid bacteria with high capacity of cholesterol-degrading. We chose Jiangshui as the experimental material, screened lactic acid bacteria by the culture medium with high cholesterol, and studied other features of lactic acid bacteria like salt-tolerant, acid resistance, then identified the species of lactic acid bacteria by combining physiological and biochemical methods and 16S rDNA sequence. All lactic acid bacteria isolated had the capacity of cholesterol-degrading to some extent. There were 4 strains had high cholesterol-degrading rate (> 75%). Four strains were Lactococcus lactis subsp. lactis, two were Brevibacterium casei, and one was Lactococcus raffinolactis. Cholesterol-degrading lactic acid bacteria were screened from Jiangshui, with application potential for cholesterol degradation.

  14. Selective growth-inhibiting effects of compounds identified in Tabebuia impetiginosa inner bark on human intestinal bacteria.

    Science.gov (United States)

    Park, Byeoung-Soo; Kim, Jun-Ran; Lee, Sung-Eun; Kim, Kyoung Soon; Takeoka, Gary R; Ahn, Young-Joon; Kim, Jeong-Han

    2005-02-23

    The growth-inhibiting activity of anthraquinone-2-carboxylic acid and lapachol identified in the inner bark of taheebo, Tabebuia impetiginosa, toward 10 human intestinal bacteria was evaluated by using a paper disk diffusion bioassay and compared to those of seven lapachol congeners (1,4-naphthoquinone, naphthazarin, menadione, lawsone, plumbagin, juglone, and dichlone) as well as two commercially available antibiotics, chloramphenicol and tetracycline. Anthraquinone-2-carboxylic acid exhibited very strong growth inhibition of Clostridium paraputrificum at 1 microg/disk while 100 microg/disk of lapachol was needed for moderate growth inhibition of the same organism. These two isolates exhibited weak inhibition of Clostridium perfringens and Escherichia coli at 100 microg/disk while no adverse effects were observed on the growth of Bifidobacterium adolescentis, Bifidobacterium bifidum, Bifidobacterium infantis, Lactobacillus acidophilus, and Lactobacillus casei at 1000 microg/disk. Structure-activity relationships indicate that a methyl group in the C-2 position of 1,4-naphthoquinone derivatives might play an important role in antibacterial activity.

  15. Modelling the effect of lactic acid bacteria from starter- and aroma culture on growth of Listeria monocytogenes in cottage cheese.

    Science.gov (United States)

    Østergaard, Nina Bjerre; Eklöw, Annelie; Dalgaard, Paw

    2014-10-01

    Four mathematical models were developed and validated for simultaneous growth of mesophilic lactic acid bacteria from added cultures and Listeria monocytogenes, during chilled storage of cottage cheese with fresh- or cultured cream dressing. The mathematical models include the effect of temperature, pH, NaCl, lactic- and sorbic acid and the interaction between these environmental factors. Growth models were developed by combining new and existing cardinal parameter values. Subsequently, the reference growth rate parameters (μref at 25°C) were fitted to a total of 52 growth rates from cottage cheese to improve model performance. The inhibiting effect of mesophilic lactic acid bacteria from added cultures on growth of L. monocytogenes was efficiently modelled using the Jameson approach. The new models appropriately predicted the maximum population density of L. monocytogenes in cottage cheese. The developed models were successfully validated by using 25 growth rates for L. monocytogenes, 17 growth rates for lactic acid bacteria and a total of 26 growth curves for simultaneous growth of L. monocytogenes and lactic acid bacteria in cottage cheese. These data were used in combination with bias- and accuracy factors and with the concept of acceptable simulation zone. Evaluation of predicted growth rates of L. monocytogenes in cottage cheese with fresh- or cultured cream dressing resulted in bias-factors (Bf) of 1.07-1.10 with corresponding accuracy factor (Af) values of 1.11 to 1.22. Lactic acid bacteria from added starter culture were on average predicted to grow 16% faster than observed (Bf of 1.16 and Af of 1.32) and growth of the diacetyl producing aroma culture was on average predicted 9% slower than observed (Bf of 0.91 and Af of 1.17). The acceptable simulation zone method showed the new models to successfully predict maximum population density of L. monocytogenes when growing together with lactic acid bacteria in cottage cheese. 11 of 13 simulations of L

  16. Nonstarter lactic acid bacteria volatilomes produced using cheese components.

    Science.gov (United States)

    Sgarbi, E; Lazzi, C; Tabanelli, G; Gatti, M; Neviani, E; Gardini, F

    2013-07-01

    In long-ripened cheese, flavor formation occurs during ripening. The metabolism of lactic acid bacteria (LAB) leads to the production of different compounds that contribute to the flavor of cheese. The contribution of LAB to the formation of cheese flavor has previously been studied. However, the specific nonstarter LAB (NSLAB) metabolic reactions in ripened cheese that lead to the formation of flavor compounds remain unclear. In ripened cheese, the nutrient sources available include small peptides or amino acids, citrate, lactate, free fatty acids, and starter LAB cell lysis products. Thus, the aim of this study was to evaluate the ability of NSLAB to produce volatile flavor compounds by using an in vitro system that used only the nutrients available in ripened cheese as the energy source. Moreover, the potential contribution of the NSLAB volatilome on total cheese flavor is discussed. For this purpose, the production of volatile compounds on cheese-based medium (CBM) and on starter LAB lysed cell medium (LCM) by 2 Lactobacillus casei and 2 Lactobacillus rhamnosus strains, previously isolated from ripened Parmigiano Reggiano cheese, was investigated. The generated volatile compounds were analyzed with head-space gas chromatography mass spectrometry. Overall, ketones, aldehydes, alcohols, and acids were the most abundant compounds produced. Differences in volatilome production were found between NSLAB grown in LCM and CBM. The catabolic metabolism of amino acids and fatty acids were required for NSLAB growth on LCM. Conversely, pyruvate metabolism was the main catabolic pathway that supported growth of NSLAB in CBM. This study can be considered a first step toward a better understanding of how microbiota involved in the long ripening of cheese may contribute to the development of cheese flavor. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  17. Insights into the evolution of sialic acid catabolism among bacteria

    Directory of Open Access Journals (Sweden)

    Almagro-Moreno Salvador

    2009-05-01

    Full Text Available Abstract Background Sialic acids comprise a family of nine-carbon amino sugars that are prevalent in mucus rich environments. Sialic acids from the human host are used by a number of pathogens as an energy source. Here we explore the evolution of the genes involved in the catabolism of sialic acid. Results The cluster of genes encoding the enzymes N-acetylneuraminate lyase (NanA, epimerase (NanE, and kinase (NanK, necessary for the catabolism of sialic acid (the Nan cluster, are confined 46 bacterial species, 42 of which colonize mammals, 33 as pathogens and 9 as gut commensals. We found a putative sialic acid transporter associated with the Nan cluster in most species. We reconstructed the phylogenetic history of the NanA, NanE, and NanK proteins from the 46 species and compared them to the species tree based on 16S rRNA. Within the NanA phylogeny, Gram-negative and Gram-positive bacteria do not form distinct clades. NanA from Yersinia and Vibrio species was most closely related to the NanA clade from eukaryotes. To examine this further, we reconstructed the phylogeny of all NanA homologues in the databases. In this analysis of 83 NanA sequences, Bacteroidetes, a human commensal group formed a distinct clade with Verrucomicrobia, and branched with the Eukaryotes and the Yersinia/Vibrio clades. We speculate that pathogens such as V. cholerae may have acquired NanA from a commensal aiding their colonization of the human gut. Both the NanE and NanK phylogenies more closely represented the species tree but numerous incidences of incongruence are noted. We confirmed the predicted function of the sialic acid catabolism cluster in members the major intestinal pathogens Salmonella enterica, Vibrio cholerae, V. vulnificus, Yersinia enterocolitica and Y. pestis. Conclusion The Nan cluster among bacteria is confined to human pathogens and commensals conferring them the ability to utilize a ubiquitous carbon source in mucus rich surfaces of the human body

  18. Recent advances in nitrogen-fixing acetic acid bacteria.

    Science.gov (United States)

    Pedraza, Raúl O

    2008-06-30

    Nitrogen is an essential plant nutrient, widely applied as N-fertilizer to improve yield of agriculturally important crops. An interesting alternative to avoid or reduce the use of N-fertilizers could be the exploitation of plant growth-promoting bacteria (PGPB), capable of enhancing growth and yield of many plant species, several of agronomic and ecological significance. PGPB belong to diverse genera, including Azospirillum, Azotobacter, Herbaspirillum, Bacillus, Burkholderia, Pseudomonas, Rhizobium, and Gluconacetobacter, among others. They are capable of promoting plant growth through different mechanisms including (in some cases), the biological nitrogen fixation (BNF), the enzymatic reduction of the atmospheric dinitrogen (N(2)) to ammonia, catalyzed by nitrogenase. Aerobic bacteria able to oxidize ethanol to acetic acid in neutral or acid media are candidates of belonging to the family Acetobacteraceae. At present, this family has been divided into ten genera: Acetobacter, Gluconacetobacter, Gluconobacter, Acidomonas, Asaia, Kozakia, Saccharibacter, Swaminathania, Neoasaia, and Granulibacter. Among them, only three genera include N(2)-fixing species: Gluconacetobacter, Swaminathania and Acetobacter. The first N(2)-fixing acetic acid bacterium (AAB) was described in Brazil. It was found inside tissues of the sugarcane plant, and first named as Acetobacter diazotrophicus, but then renamed as Gluconacetobacter diazotrophicus. Later, two new species within the genus Gluconacetobacter, associated to coffee plants, were described in Mexico: G. johannae and G. azotocaptans. A salt-tolerant bacterium named Swaminathania salitolerans was found associated to wild rice plants. Recently, N(2)-fixing Acetobacter peroxydans and Acetobacter nitrogenifigens, associated with rice plants and Kombucha tea, respectively, were described in India. In this paper, recent advances involving nitrogen-fixing AAB are presented. Their natural habitats, physiological and genetic aspects

  19. Effects of hops (Humulus lupulus L.) extract on volatile fatty acid production by rumen bacteria.

    Science.gov (United States)

    Flythe, M D; Aiken, G E

    2010-10-01

    To determine the effects of hops extract on in vitro volatile fatty acid (VFA) production by bovine rumen micro-organisms. When mixed rumen microbes were suspended in media containing carbohydrates, the initial rates of VFA production were suppressed by β-acid-rich hops extract. The rates of VFA production increased over extended incubations (24 h), and hops extract caused an increase in the propionate to acetate ratio. Hops extract inhibited the growth and metabolism of Streptococcus bovis, but Selenomonas ruminantium and Megasphaera elsdenii were not affected. Likewise, the propionate production of M. elsdenii/S. bovis co-cultures, but not M. elsdenii/S. ruminantium co-cultures, was decreased in the presence of hops extract. These results are consistent with the hypothesis that the hops inhibit Gram-positive lactic acid bacteria (S. bovis), and the rumen microbial community requires a period of adaptation before normal VFA production resumes. Selenomonas bovis and S. ruminantium both produce lactate, which is the substrate for propionate production by M. elsdenii. However, S. ruminantium has an outer membrane, while S. bovis does not. The enhanced production of the gluconeogenesis precursor, propionic acid, provides further evidence that plant secondary metabolites from hops could be used to improve rumen fermentation. Journal compilation © 2010 The Society for Applied Microbiology. No claim to US Government works.

  20. UJI SIFAT PROBIOTIK BAKTERI ASAM LAKTAT SEBAGAI KANDIDAT BAHAN PANGAN FUNGSIONAL [Probiotic Characteristics of laactic acid Bacteria as Candidate for Functional Food

    Directory of Open Access Journals (Sweden)

    Ida Susanti

    2007-12-01

    Full Text Available Lactic acid bacteria have been reported to be useful as a healt adjunct and are commonly added to food as delivery mechanism. As a probiotic, lactic acid bacteria should have the ability to survive in the digestion process such as resistance towards acidic pH, varieties of bile salt concentrations and enteric pathogan. In this study, lactic acid bacteria were isolated from various sources. Twenty isolated of lactic acid bacteria selected for their resistancy toeards acidic pH (pH 2.5, 0.3% bile salt and their antagonistic activity against enteric pathogan (Esherichia coli, Staphylococcus aureus and Bacillus cereus. The result showed that most of all strauns had good resistance to acidic pH and there were no significant difference among theme (p>0.05. More over, all strains showed tolerance to 0,3% bile salt concentration (varietis among isolates were significant p>0.05. All strains showed inhibition activity against enteric pathogan bacteria, this was estimated from the size of the diameter of the inhibition zones. (The inhibition were significantly different among them (p>0,05. The best five stains that fulfilled these properties L casei FNCC262, L. acidophilus FNCC116, KL-3 isolate, Da-1 isolate, and Db-2 isolate. These strains could be used as probiotics in further and applications.

  1. Differential Real-Time PCR Assay for Enumeration of Lactic Acid Bacteria in Wine

    Science.gov (United States)

    Neeley, Ezekiel T.; Phister, Trevor G.; Mills, David A.

    2005-01-01

    Oenococcus oeni is often employed to perform the malolactic fermentation in wine production, while nonoenococcal lactic acid bacteria often contribute to wine spoilage. Two real-time PCR assays were developed to enumerate the total, and nonoenococcal, lactic acid bacterial populations in wine. Used together, these assays can assess the spoilage risk of juice or wine from lactic acid bacteria. PMID:16332898

  2. Isolation and identification of lactic acid bacteria from abalone (Haliotis asinina as a potential candidate of probiotic

    Directory of Open Access Journals (Sweden)

    YAYAN SOFYAN

    2010-01-01

    Full Text Available Sarkono, Faturrahman, Sofyan Y. 2010. Isolation and identification of lactic acid bacteria from abalone (Haliotis asinina as a potential candidate of probiotic. Nusantara Bioscience 2: 38-42. The purpose of this study was to isolate, select and characterize lactic acid bacteria (LAB from abalone as a potential candidate probiotic in abalone cultivation system. Selective isolation of LAB performed using de Man Rogosa Sharpe medium. LAB isolate that potential as probiotics was screened. Selection was based on its ability to suppress the growth of pathogenic bacteria, bacterial resistance to acidic conditions and bacterial resistance to bile salts (bile. Further characterization and identification conducted to determine the species. The results showed that two of the ten isolates potential to be developed as probiotic bacteria that have the ability to inhibit several pathogenic bacteria such as Eschericia coli, Bacillus cereus dan Staphylococus aureus, able to grow at acidic condition and bile tolerance during the incubation for 24 hour. Based on the API test kit, the both of isolate identified as members of the species Lactobacillus paracasei ssp. paracasei.

  3. Purification Techniques of Bacteriocins from Lactic Acid Bacteria and Other Gram-Positive Bacteria

    Science.gov (United States)

    Saavedra, Lucila; Sesma, Fernando

    The search for new antimicrobial peptides produced by lactic acid ­bacteria and other Gram-positive microorganisms has become an interesting field of research in the past decades. The fact that bacteriocins are active against numerous foodborne and human pathogens, are produced by generally regarded as safe (GRAS) microorganisms, and are readily degraded by proteolytic host systems makes them attractive candidates for biotechnological applications. However, before suggesting or choosing a new bacteriocin for future technology developments, it is necessary to elucidate its biochemical structure and its mode of action, which may be carried out once the bacteriocin is purified to homogeneity. This chapter focuses on describing the main strategies used for the purification of numerous bacteriocins.

  4. Olfactory attraction of Drosophila suzukii by symbiotic acetic acid bacteria

    KAUST Repository

    Mazzetto, Fabio

    2016-03-24

    Some species of acetic acid bacteria (AAB) play relevant roles in the metabolism and physiology of Drosophila spp. and in some cases convey benefits to their hosts. The pest Drosophila suzukii harbors a set of AAB similar to those of other Drosophila species. Here, we investigate the potential to exploit the ability of AAB to produce volatile substances that attract female D. suzukii. Using a two-way olfactometer bioassay, we investigate the preference of D. suzukii for strains of AAB, and using solid-phase microextraction gas chromatography–mass spectrometry we specifically characterize their volatile profiles to identify attractive and non-attractive components produced by strains from the genera Acetobacter, Gluconobacter, and Komagataeibacter. Flies had a preference for one strain of Komagataeibacter and two strains of Gluconobacter. Analyses of the volatile profiles from the preferred Gluconobacter isolates found that acetic acid is distinctively emitted even after 2 days of bacterial growth, confirming the relevance of this volatile in the profile of this isolate for attracting flies. Analyses of the volatile profile from the preferred Komagataeibacter isolate showed that a different volatile in its profile could be responsible for attracting D. suzukii. Moreover, variation in the concentration of butyric acid derivatives found in some strains may influence the preference of D. suzukii. Our results indicate that Gluconobacter and Komagataeibacter strains isolated from D. suzukii have the potential to provide substances that could be exploited to develop sustainable mass-trapping-based control approaches. © 2016 Springer-Verlag Berlin Heidelberg

  5. Interactions between Cooccurring Lactic Acid Bacteria in Honey Bee Hives.

    Science.gov (United States)

    Rokop, Z P; Horton, M A; Newton, I L G

    2015-10-01

    In contrast to the honey bee gut, which is colonized by a few characteristic bacterial clades, the hive of the honey bee is home to a diverse array of microbes, including many lactic acid bacteria (LAB). In this study, we used culture, combined with sequencing, to sample the LAB communities found across hive environments. Specifically, we sought to use network analysis to identify microbial hubs sharing nearly identical operational taxonomic units, evidence which may indicate cooccurrence of bacteria between environments. In the process, we identified interactions between noncore bacterial members (Fructobacillus and Lactobacillaceae) and honey bee-specific "core" members. Both Fructobacillus and Lactobacillaceae colonize brood cells, bee bread, and nectar and may serve the role of pioneering species, establishing an environment conducive to the inoculation by honey bee core bacteria. Coculture assays showed that these noncore bacterial members promote the growth of honey bee-specific bacterial species. Specifically, Fructobacillus by-products in spent medium supported the growth of the Firm-5 honey bee-specific clade in vitro. Metabolic characterization of Fructobacillus using carbohydrate utilization assays revealed that this strain is capable of utilizing the simple sugars fructose and glucose, as well as the complex plant carbohydrate lignin. We tested Fructobacillus for antibiotic sensitivity and found that this bacterium, which may be important for establishment of the microbiome, is sensitive to the commonly used antibiotic tetracycline. Our results point to the possible significance of "noncore" and environmental microbial community members in the modulation of honey bee microbiome dynamics and suggest that tetracycline use by beekeepers should be limited. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  6. Acid tolerance response and survival by oral bacteria.

    Science.gov (United States)

    Svensäter, G; Larsson, U B; Greif, E C; Cvitkovitch, D G; Hamilton, I R

    1997-10-01

    Using 21 species of oral bacteria, representing six acidogenic genera, we undertook to determine whether the pH-limiting exponential growth is related to the ability of the organisms to generate an acid-tolerance response that results in enhanced survival at low pH. The lower pH limit of exponential growth varied by more than two units with that of Neisseria A182 at pH 6.34; growth of Lactobacillus casei RB1014 stopped at pH 3.81, with species of Actinomyces, Enterococcus, Prevotella and Streptococcus falling between these limits. The working hypothesis was that the organisms with the higher pH limits for growth are unable to respond to acidic environments in order to survive, whereas the more aciduric organisms would possess or acquire acid tolerance. Adaptation to acid tolerance was tested by determining whether the prior exposure of exponential-phase cells to a low, sub-lethal pH would trigger the induction of a mechanism that would enhance survival at a pH killing pH 7.5 control cells. The killing pH varied from pH 4.5 for Prevotella intermedia ATCC 25611 to pH 2.3 for the three Lactobacillus casei strains in the study, with the three Streptococcus mutans strains killed at pH 3.0 for 3 h. The adaptation experiments revealed three groups of organisms: non-acid-responders, generally representing strains with the highest terminal pH values; weak acid-responders in the middle of the pH list, generating low numbers of survivors at one or two pH values, and the aciduric, strong responders generating a high number of survivors at pH values in the range 6.0 to 3.5, but not at pH 7.5. Predominant among the latter group were the S. mutans and Lactobacilli casei strains, with the most significant adaptive response exhibited by S. mutans LT11 and S. mutans Ingbritt, involving a process that required protein synthesis. Time course experiments with the latter organisms indicated that 90-120 min was required after exposure to the triggering pH before the acid response was

  7. Comparative Growth Behaviour and Biofunctionality of Lactic Acid Bacteria During Fermentation of Soy Milk and Bovine Milk.

    Science.gov (United States)

    Hati, Subrota; Patel, Nikita; Mandal, Surajit

    2017-04-29

    The study reports the growth, acidification and proteolysis of eight selected lactic acid bacteria in skim and soy milk. Angiotensin-converting enzyme inhibition and antimicrobial profiles of skim and soy milk fermented by the lactic acid bacteria were also determined. Among eight lactic cultures (S. thermophilus MD2, L. helveticus V3, L. rhamnosus NS6, L. rhamnosus NS4, L. bulgaricus NCDC 09, L. acidophilus NCDC 15, L. acidophilus NCDC 298 and L. helveticus NCDC 292) studied, L. bulgaricus NCDC 09 and S. thermophilus MD2 decreased the pH of skim and soy milk in greater extent. Acid production (i.e. titratable acidity) by L. bulgaricus NCDC 09 and L. helveticus V3 was higher than other strains. Higher viable counts were observed in S. thermophilus MD2 and L. helveticus V3. Higher proteolysis was exhibited by S. thermophilus MD2 and L. rhamnosus NS6 in both skim and soy milk. Milk fermented by S. thermophilus (MD2) exhibited highest angiotensin-converting enzyme inhibition. Antimicrobial activities of cell-free supernatant of milk fermented by S. thermophilus MD2 and L. helveticus V3 were higher. All the tested lactic acid bacteria performed better in skim milk as compared to soy milk.

  8. Characterization of Bacteriocin-Producing Lactic Acid Bacteria Isolated from Native Fruits of Ecuadorian Amazon.

    Science.gov (United States)

    Garzón, Karina; Ortega, Clara; Tenea, Gabriela N

    2017-12-04

    Tropical, wild-type fruits are considered biodiverse "hotspots" of microorganisms with possible functional characteristics to be investigated. In this study, several native lactic acid bacteria (LAB) of Ecuadorian Amazon showing highly inhibitory potential were identified and characterized. Based on carbohydrate fermentation profile and 16S rRNA gene sequencing, seven strains were assigned as Lactobacillus plantarum and one strain as Weissella confusa. Using agar-well diffusion method the active synthetized components released in the neutralized and hydroxide peroxide eliminated cell-free supernatant were inhibited by proteolytic enzymes, while the activity was maintained stable after the treatment with catalase, lysozyme, α-amylase and lipase suggesting their proteinaceous nature. The inhibitory activity was stimulated by acidic conditions, upon exposure to high heat and maintained stable at different ranges of sodium chloride (4-10%). The DNA sequencing analysis confirmed the presence of plw structural gene encoding for plantacirin W in the selected L. plantarum strains. Moreover, we showed that the active peptides of Cys5-4 strains contrast effectively, in a bactericidal manner, the growth of food borne E. coli UTNEc1 and Salmonella UTNSm2, with about tree fold reduction of viable counts at the early stage of the target cell growth. The results indicated that the bacteriocin produced by selected native lactic acid bacteria strains has elevated capacity to suppress several pathogenic microorganisms implying their potential as antimicrobial agents or food preservatives.

  9. Adhesion Properties of Lactic Acid Bacteria on Intestinal Mucin

    Directory of Open Access Journals (Sweden)

    Keita Nishiyama

    2016-09-01

    Full Text Available Lactic acid bacteria (LAB are Gram-positive bacteria that are natural inhabitants of the gastrointestinal (GI tracts of mammals, including humans. Since Mechnikov first proposed that yogurt could prevent intestinal putrefaction and aging, the beneficial effects of LAB have been widely demonstrated. The region between the duodenum and the terminal of the ileum is the primary region colonized by LAB, particularly the Lactobacillus species, and this region is covered by a mucus layer composed mainly of mucin-type glycoproteins. The mucus layer plays a role in protecting the intestinal epithelial cells against damage, but is also considered to be critical for the adhesion of Lactobacillus in the GI tract. Consequently, the adhesion exhibited by lactobacilli on mucin has attracted attention as one of the critical factors contributing to the persistent beneficial effects of Lactobacillus in a constantly changing intestinal environment. Thus, understanding the interactions between Lactobacillus and mucin is crucial for elucidating the survival strategies of LAB in the GI tract. This review highlights the properties of the interactions between Lactobacillus and mucin, while concomitantly considering the structure of the GI tract from a histochemical perspective.

  10. Future access and improvement of industrial lactic acid bacteria cultures.

    Science.gov (United States)

    Johansen, Eric

    2017-12-21

    Industrial fermentations based on micro-organisms such as the lactic acid bacteria (LAB) play an important role in several industries globally and represent multi-billion Euro/dollar businesses. LAB provide a natural way to produce safe, sustainable, and environmentally friendly products for a variety of industries. Product innovation is a key requirement for these industries to survive and grow globally. However, the development of new products may be affected by two man-made constraints; the Nagoya Protocol on benefit sharing and the opposition to the use of modern biotechnology for strain improvement. An expert workshop was held in Amsterdam, May 10-11, 2017 to discuss these challenges; a number of conclusions and recommendations were formulated and will be presented herein.

  11. Recombinant lactic acid bacteria as mucosal biotherapeutic agents.

    Science.gov (United States)

    Daniel, Catherine; Roussel, Yvonne; Kleerebezem, Michiel; Pot, Bruno

    2011-10-01

    The safety status of lactic acid bacteria (LAB) and their capacity to survive the passage through the gastrointestinal tract (GI tract) have rendered them excellent candidates for the production of therapeutic proteins and their delivery in situ to the GI tract. During the past two decades, major health benefits of mucosally administered recombinant LAB have been successfully demonstrated, predominantly using animal models. However, the field has recently moved into the era of human clinical trials. In this review, we provide a timely update on the recent important advances made in this field, and outline the potential of recombinant LAB as therapeutic tools for their safe and efficient use in human health. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Lactic acid bacteria as adjuvants for sublingual allergy vaccines.

    Science.gov (United States)

    Van Overtvelt, Laurence; Moussu, Helene; Horiot, Stéphane; Samson, Sandrine; Lombardi, Vincent; Mascarell, Laurent; van de Moer, Ariane; Bourdet-Sicard, Raphaëlle; Moingeon, Philippe

    2010-04-09

    We compared immunomodulatory properties of 11 strains of lactic acid bacteria as well as their capacity to enhance sublingual immunotherapy efficacy in a murine asthma model. Two types of bacterial strains were identified, including: (i) potent inducers of IL-12p70 and IL-10 in dendritic cells, supporting IFN-gamma and IL-10 production in CD4+ T cells such as Lactobacillus helveticus; (ii) pure Th1 inducers such as L. casei. Sublingual administration in ovalbumin-sensitized mice of L. helveticus, but not L. casei, reduced airways hyperresponsiveness, bronchial inflammation and proliferation of specific T cells in cervical lymph nodes. Thus, probiotics acting as a Th1/possibly Treg, but not Th1 adjuvant, potentiate tolerance induction via the sublingual route. Copyright 2010 Elsevier Ltd. All rights reserved.

  13. Biotyping of cultivable lactic acid bacteria isolated from donkey milk.

    Science.gov (United States)

    Carminati, D; Tidona, F; Fornasari, M E; Rossetti, L; Meucci, A; Giraffa, G

    2014-09-01

    The diversity of lactic acid bacteria (LAB) species in donkey's milk was analysed by culture-dependent microbial techniques. Dominant strains were isolated on agar media generally used for enumerating LAB. To enrich the number of acidifying LAB present, the milk samples were incubated at 37°C for 24 h (cultured milk samples, CM). One of the CM samples was heat-treated at 63°C for 10 min before incubation at 37°C (heat-treated and cultured milk sample, TCM) to select thermophilic LAB. The microflora in these CM and TCM samples was then compared to that of the raw milk samples (RM). Among the 129 LAB isolates, 10 different species (four Enterococcus, five Streptococcus and one Pediococcus) were identified by molecular methods. Although the 10 LAB species were present in the RM samples, only three and two isolates were found in CM and TCM samples, respectively. Despite the selection protocol being set up to favour the isolation of all LAB isolates present in donkey milk, relatively few species and biotypes were isolated. No LAB isolates belonging to the most technologically important dairy starter species were detected. The possible factors related to the limited LAB diversity in donkey's milk have been discussed below. There is increased interest in using donkey's milk as a source of human nutrition. The large amounts of antimicrobial components and defence factors present in donkey's milk provide protection from microbial infections and distinguish donkey's milk from the milks of other mammals. However, the microbiota in donkey's milk has so far been poorly characterized, specifically with regard to the lactic acid bacteria (LAB). This study has identified cultivable, acidifying and thermoduric LAB that could be used to develop starter cultures. This is the first study to investigate the culturable LAB microbiota present in donkey's milk. © 2014 The Society for Applied Microbiology.

  14. [Synthesis and degradation of hyaluronic acid by bacteria of Streptococcus genus].

    Science.gov (United States)

    Beloded, A V; Samoĭlenko, I I; Tsepilov, R N

    2010-01-01

    Modern data on metabolism of hyaluronic acid by bacteria from Streptococcus genus are presented. Several species of bacteria forming capsule from hyaluronic acid, which is analogous to glycosaminoglycan of vertebrates, are considered. Different aspects of hyaluronic acid synthesis are described: biochemical synthesis pathway, genetic basis, regulation of expression of genes belonging to hyaluronic acid synthesis operon. Biological role and physiologic importance of hyaluronic acid for bacteria, including its role in overcoming immune barrier by pathogenic species, are discussed. Process of depolymerization of hyaluronic acid in presence of hyaluronatlyases secreted by certain streptococci is considered. Characteristic of streptococcal enzyme hyaluronatlyase, its mechanism of catalytic effect, and biological function are presented.

  15. Phenolic acid degradation potential and growth behavior of lactic acid bacteria in sunflower substrates.

    Science.gov (United States)

    Fritsch, Caroline; Heinrich, Veronika; Vogel, Rudi F; Toelstede, Simone

    2016-08-01

    Sunflower flour provides a high content of protein with a well-balanced amino acid composition and is therefore regarded as an attractive source for protein. The use for human nutrition is hindered by phenolic compounds, mainly chlorogenic acid, which can lead under specific circumstances to undesirable discolorations. In this study, growth behavior and degradation ability of chlorogenic acid of four lactic acid bacteria were explored. Data suggested that significant higher fermentation performances on sunflower flour as compared to sunflower protein concentrate were reached by Lactobacillus plantarum, Pediococcus pentosaceus, Lactobacillus gasseri and Bifidobacterium animalis subsp. lactis. In fermentation with the latter two strains reduced amounts of chlorogenic acid were observed in sunflower flour (-11.4% and -19.8%, respectively), which were more pronounced in the protein concentrate (-50.7% and -95.6%, respectively). High tolerances against chlorogenic acid and the cleavage product quinic acid with a minimum inhibitory concentration (MIC) of ≥20.48 mg/ml after 48 h were recorded for all strains except Bifidobacterium animalis subsp. lactis, which was more sensitive. The second cleavage compound, caffeic acid revealed a higher antimicrobial potential with MIC values of 0.64-5.12 mg/ml. In this proof of concept study, degradation versus inhibitory effect suggest the existence of basic mechanisms of interaction between phenolic acids in sunflower and lactic acid bacteria and a feasible way to reduce the chlorogenic acid content, which may help to avoid undesired color changes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Inhibition of aflatoxin-producing aspergilli by lactic acid bacteria ...

    African Journals Online (AJOL)

    If you would like more information about how to print, save, and work with PDFs, Highwire Press provides a helpful Frequently Asked Questions about PDFs. Alternatively, you can download the PDF file directly to your computer, from where it can be opened using a PDF reader. To download the PDF, click the Download link ...

  17. Antigenotoxic activity of lactic acid bacteria, prebiotics, and products of their fermentation against selected mutagens.

    Science.gov (United States)

    Nowak, Adriana; Śliżewska, Katarzyna; Otlewska, Anna

    2015-12-01

    Dietary components such as lactic acid bacteria (LAB) and prebiotics can modulate the intestinal microbiota and are thought to be involved in the reduction of colorectal cancer risk. The presented study measured, using the comet assay, the antigenotoxic activity of both probiotic and non-probiotic LAB, as well as some prebiotics and the end-products of their fermentation, against fecal water (FW). The production of short chain fatty acids by the bacteria was quantified using HPLC. Seven out of the ten tested viable strains significantly decreased DNA damage induced by FW. The most effective of them were Lactobacillus mucosae 0988 and Bifidobacterium animalis ssp. lactis Bb-12, leading to a 76% and 80% decrease in genotoxicity, respectively. The end-products of fermentation of seven prebiotics by Lactobacillus casei DN 114-001 exhibited the strongest antigenotoxic activity against FW, with fermented inulin reducing genotoxicity by 75%. Among the tested bacteria, this strain produced the highest amounts of butyrate in the process of prebiotic fermentation, and especially from resistant dextrin (4.09 μM/mL). Fermented resistant dextrin improved DNA repair by 78% in cells pre-treated with 6.8 μM methylnitronitrosoguanidine (MNNG). Fermented inulin induced stronger DNA repair in cells pre-treated with mutagens (FW, 25 μM hydrogen peroxide, or MNNG) than non-fermented inulin, and the efficiency of DNA repair after 120 min of incubation decreased by 71%, 50% and 70%, respectively. The different degrees of genotoxicity inhibition observed for the various combinations of bacteria and prebiotics suggest that this effect may be attributable to carbohydrate type, SCFA yield, and the ratio of the end-products of prebiotic fermentation. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. A prebiotic role of Ecklonia cava improves the mortality of Edwardsiella tarda-infected zebrafish models via regulating the growth of lactic acid bacteria and pathogen bacteria.

    Science.gov (United States)

    Lee, WonWoo; Oh, Jae Young; Kim, Eun-A; Kang, Nalae; Kim, Kil-Nam; Ahn, Ginnae; Jeon, You-Jin

    2016-07-01

    In this study, the beneficial prebiotic roles of Ecklonia cava (E. cava, EC) were evaluated on the growth of lactic acid bacteria (LAB) and pathogen bacteria and the mortality of pathogen-bacteria infected zebrafish model. The result showed that the original E. cava (EC) led to the highest growth effects on three LABs (Lactobacillus brevis, L. brevis; Lactobacillus pentosus, L. pentosus; Lactobacillus plantarum; L. plantarum) and it was dose-dependent manners. Also, EC, its Celluclast enzymatic (ECC) and 100% ethanol extracts (ECE) showed the anti-bacterial activities on the fish pathogenic bacteria such as (Edwardsiella tarda; E. tarda, Streptococcus iniae; S. iniae, and Vibrio harveyi; V. harveyi). Interestingly, EC induced the higher production of the secondary metabolites from L. plantarum in MRS medium. The secondary metabolites produced by EC significantly inhibited the growth of pathogen bacteria. In further in vivo study, the co-treatment of EC and L. plantarum improved the growth and mortality of E. tarda-infected zebrafish as regulating the expression of inflammatory molecules such as iNOS and COX2. Taken together, our present study suggests that the EC plays an important role as a potential prebiotic and has a protective effect against the infection caused by E. tarda injection in zebrafish. Also, our conclusion from this evidence is that EC can be used and applied as a useful prebiotic. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Screening of Lactic Acid Bacteria for Anti-Fusarium Activity and Optimization of Incubation Conditions.

    Science.gov (United States)

    Zhao, Hui; Vegi, Anuradha; Wolf-Hall, Charlene

    2017-10-01

    Anti-Fusarium activities of lactic acid bacteria (LAB) Lactobacillus plantarum 299V, L. plantarum NRRL-4496, and Lactobacillus rhamnosus VT1 were determined by a microdilution assay developed in this study against Fusarium graminearum 08/RG/BF/51. A cell-free Lactobacillus culture supernatant (CFLCS) of L. rhamnosus VT1 had the highest anti-Fusarium activity. Response surface methodology was used to optimize the incubation conditions for production of CFLCS. A Box-Behnken factorial design was used to investigate the effects of incubation time, shaking speed, and incubation temperature on the inhibition rate of CFLCS. A model equation was generated to predict the inhibition rate of CFLCS under various incubation conditions. A low probability value (0.0012) and associated F value of 25.10 suggested that the model was highly significant. A high R 2 value (0.978) indicated a very satisfactory model performance. Response surface methodology analysis suggested that an incubation temperature at 34°C, a shaking speed at 170 rpm, and an incubation time of 55 h were the best combination for production of CFLCS from L. rhamnosus VT1. Under these incubation conditions, a 10% L. rhamnosus VT1 CFLCS solution was predicted to inhibit the growth of F. graminearum by 75.6% in vitro and inhibited 83.7% of the growth in the validation experiment. Thus, the CFLCS of L. rhamnosus VT1 was an effective anti-Fusarium mixture.

  20. Characterization of Exopolysaccharides Produced by Thermophilic Lactic Acid Bacteria Isolated from Tropical Fruits of Thailand.

    Science.gov (United States)

    Panthavee, Wanchai; Noda, Masafumi; Danshiitsoodol, Narandalai; Kumagai, Takanori; Sugiyama, Masanori

    2017-01-01

    In the present study, we have obtained two exopolysaccharide (EPS)-producing thermophilic lactic acid bacteria (LAB) that were isolated from tropical fruits of Thailand. The two strains, designated LY45 and PY45, were identified as Pediococcus pentosaceus and Lactobacillus amylovorus, respectively. Both plant-derived LAB strains, which produce neutral EPSs together with the acidic one, can grow vigorously at 45°C and even at 50°C. Hyaluronidase (EC 3.2.1.35), which catalyzes the degradation of hyaluronic acid, activates an inflammatory reaction. Interestingly, EPSs produced by the LY45 and PY45 strains were found to inhibit hyaluronidase activity at the same order of IC 50 values as did sodium cromoglicate and dipotassium glycyrrhizinate, which are well-known as anti-inflammatory agents. The LY45-derived neutral EPS consists of glucose and mannose as monosaccharide components, whereas the acidic one contains mainly mannose, together with glucose and galactose. On the other hand, although Lactobacillus amylovorus PY45 also produces neutral and acidic EPSs, the main monosaccharide in both EPSs is mannose, and glucose is a minor component. Furthermore, the PY45 strain may be probiotically and industrially useful because the microorganism can utilize starch and glycogen as carbon sources.

  1. Properties of Kimchi Fermented with GABA-Producing Lactic Acid Bacteria as a Starter.

    Science.gov (United States)

    Lee, Kang Wook; Shim, Jae Min; Yao, Zhuang; Kim, Jeong A; Kim, Jeong Hwan

    2018-02-13

    Kimchi was prepared with a starter, Lactobacillus zymae GU240 producing γ-aminobutyric acid (GABA), and one precursor of GABA (glutamic acid, glutamic acid mono sodium salt (MSG), or kelp extract). L. zymae GU240, an isolate from kimchi, can grow at 7% NaCl and low temperature. Five different kimchi samples were fermented for 20 weeks at -1°C. Kimchi with starter alone could not produce GABA. GABA content was highest in kimchi with co-inoculation of starter and MSG (1%, w/w). Kimchi co-inoculated with a starter and kelp extract powder (3%, w/w) had the second highest GABA content. Addition of glutamic acid powder (1%, w/w) caused a reduction in the pH level of kimchi and growth inhibition of lactic acid bacteria (LAB) and yeasts. Kimchi samples with MSG or kelp extract showed improvement of sensory evaluation scores. The results demonstrate the possibility to produce kimchi with improved functionality and taste by using L. zymae GU240 as a starter along with a suitable precursor such as MSG or kelp extract.

  2. NATURE OF THE LIPIDS OF SOME LACTIC ACID BACTERIA1

    Science.gov (United States)

    Ikawa, Miyoshi

    1963-01-01

    Ikawa, Miyoshi (University of California, Berkeley). Nature of the lipids of some lactic acid bacteria. J. Bacteriol. 85:772–781. 1963.—Lactobacillus casei, L. plantarum, Leuconostoc mesenteroides, Pediococcus cerevisiae, and Streptococcus faecalis were grown on a lipid-free medium, and the amounts of acetone-soluble lipids, acetone-insoluble phospholipids, and unextracted or bound lipid in the cells were estimated. Neutral glycerides appeared to be absent, or present only in traces, in L. casei and S. faecalis. L. plantarum, L. mesenteroides, and P. cerevisiae, in addition to containing glycerides, appeared to contain glycolipids of glucose and galactose. Glycerol was present in the phospholipid fraction of all the organisms, and, in addition, galactose was present in L. mesenteroides. Paper chromatography of hydrolysates of the phospholipid fractions showed the absence of the usual phospholipid nitrogen bases, serine, ethanolamine, and choline, in these organisms. Microbiological assays of lyophilized unextracted cells for myo-inositol and choline also showed that lipids containing these components occurred in very small amounts at most. The principal ninhydrin-reacting substance in the phospholipid fraction of L. casei, L. plantarum, P. cerevisiae, and S. faecalis was lysine, which seemed to be exclusively of the l configuration. The principal ninhydrin-reacting substance in the L. mesenteroides phospholipid fraction was d-alanine. These amino acids appeared to be bound in components of the phospholipid fraction and not free. Images PMID:14044942

  3. Impact of lactic acid bacteria on conjugated linoleic acid content and atherogenic index of butter

    Directory of Open Access Journals (Sweden)

    L Roufegari-Nejad

    2012-11-01

    Full Text Available This is a study aimed to investigate the effect of lactic acid bacteria including Lactobacillus acidophilus and Sterptococcus thermophilus (as thermophilic culture, Lactococcus lactis subsp. lactis, cremoris and diacetylactis, Leuconostoc citrovorum (as mesophilic culture, Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium lactis and a mixed culture of L.acidophilus, L. casei and B. lactis on fatty acid profile, conjugated linoleic acid (CLA and atherogenic index (AI of butter. Fatty acid analysis with gas chromatography indicated that application of thermophilic and mixed culture decreased the ratio of saturated to unsaturated fatty acid; whereas, the butters made with L. acidophilus had the highest content of CLA. Moreover, AI in the samples prepared with thermophilic cultures was the least. Sensory evaluation of the treatments revealed no significant differences (p> 0/05 in appearance and color. However, the butters prepared with thermophilic and mesophilic cultures had more desirable taste in comparison with the samples made with L. acidophilus, L. casei and B. lactis. From the nutritional point of view, the adverse effect of butter could be diminished via the application of selected lactic acid bacteria.

  4. Lactic Acid Bacteria Selection for Biopreservation as a Part of Hurdle Technology Approach Applied on Seafood

    Directory of Open Access Journals (Sweden)

    Norman Wiernasz

    2017-05-01

    Full Text Available As fragile food commodities, microbial, and organoleptic qualities of fishery and seafood can quickly deteriorate. In this context, microbial quality and security improvement during the whole food processing chain (from catch to plate, using hurdle technology, a combination of mild preserving technologies such as biopreservation, modified atmosphere packaging, and superchilling, are of great interest. As natural flora and antimicrobial metabolites producers, lactic acid bacteria (LAB are commonly studied for food biopreservation. Thirty-five LAB known to possess interesting antimicrobial activity were selected for their potential application as bioprotective agents as a part of hurdle technology applied to fishery products. The selection approach was based on seven criteria including antimicrobial activity, alteration potential, tolerance to chitosan coating, and superchilling process, cross inhibition, biogenic amines production (histamine, tyramine, and antibiotics resistance. Antimicrobial activity was assessed against six common spoiling bacteria in fishery products (Shewanella baltica, Photobacterium phosphoreum, Brochothrix thermosphacta, Lactobacillus sakei, Hafnia alvei, Serratia proteamaculans and one pathogenic bacterium (Listeria monocytogenes in co-culture inhibitory assays miniaturized in 96-well microtiter plates. Antimicrobial activity and spoilage evaluation, both performed in cod and salmon juice, highlighted the existence of sensory signatures and inhibition profiles, which seem to be species related. Finally, six LAB with no unusual antibiotics resistance profile nor histamine production ability were selected as bioprotective agents for further in situ inhibitory assays in cod and salmon based products, alone or in combination with other hurdles (chitosan, modified atmosphere packing, and superchilling.

  5. Modelling the effect of lactic acid bacteria from starter- and aroma culture on growth of Listeria monocytogenes in cottage cheese

    DEFF Research Database (Denmark)

    Østergaard, Nina Bjerre; Eklöw, Annelie; Dalgaard, Paw

    2014-01-01

    Four mathematical models were developed and validated for simultaneous growth of mesophilic lactic acid bacteria from added cultures and Listeria monocytogenes, during chilled storage of cottage cheese with freshor cultured cream dressing. The mathematical models include the effect of temperature...... cheese to improvemodel performance. The inhibiting effect of mesophilic lactic acid bacteria from added cultures on growth of L. monocytogenes was efficiently modelled using the Jameson approach. The new models appropriately predicted the maximum population density of L. monocytogenes in cottage cheese......- and accuracy factors and with the concept of acceptable simulation zone. Evaluation of predicted growth rates of L. monocytogenes in cottage cheese with fresh- or cultured cream dressing resulted in bias-factors (Bf) of 1.07–1.10with corresponding accuracy factor (Af) values of 1.11 to 1.22. Lactic acid...

  6. Thyroid peroxidase activity is inhibited by amino acids

    Directory of Open Access Journals (Sweden)

    D.P. Carvalho

    2000-03-01

    Full Text Available Normal in vitro thyroid peroxidase (TPO iodide oxidation activity was completely inhibited by a hydrolyzed TPO preparation (0.15 mg/ml or hydrolyzed bovine serum albumin (BSA, 0.2 mg/ml. A pancreatic hydrolysate of casein (trypticase peptone, 0.1 mg/ml and some amino acids (cysteine, tryptophan and methionine, 50 µM each also inhibited the TPO iodide oxidation reaction completely, whereas casamino acids (0.1 mg/ml, and tyrosine, phenylalanine and histidine (50 µM each inhibited the TPO reaction by 54% or less. A pancreatic digest of gelatin (0.1 mg/ml or any other amino acid (50 µM tested did not significantly decrease TPO activity. The amino acids that impair iodide oxidation also inhibit the TPO albumin iodination activity. The inhibitory amino acids contain side chains with either sulfur atoms (cysteine and methionine or aromatic rings (tyrosine, tryptophan, histidine and phenylalanine. Among the amino acids tested, only cysteine affected the TPO guaiacol oxidation reaction, producing a transient inhibition at 25 or 50 µM. The iodide oxidation inhibitory activity of cysteine, methionine and tryptophan was reversed by increasing iodide concentrations from 12 to 18 mM, while no such effect was observed when the cofactor (H2O2 concentration was increased. The inhibitory substances might interfere with the enzyme activity by competing with its normal substrates for their binding sites, binding to the free substrates or reducing their oxidized form.

  7. Differential oxidative and antioxidative response of duckweed Lemna minor toward plant growth promoting/inhibiting bacteria.

    Science.gov (United States)

    Ishizawa, Hidehiro; Kuroda, Masashi; Morikawa, Masaaki; Ike, Michihiko

    2017-09-01

    Bacteria colonizing the plant rhizosphere are believed to positively or negatively affect the host plant productivity. This feature has inspired researchers to engineer such interactions to enhance crop production. However, it remains to be elucidated whether rhizobacteria influences plant oxidative stress vis-a-vis other environmental stressors, and whether such influence is associated with their growth promoting/inhibiting ability. In this study, two plant growth-promoting bacteria (PGPB) and two plant growth-inhibiting bacteria (PGIB) were separately inoculated into axenic duckweed (Lemna minor) culture under laboratory conditions for 4 and 8 days in order to investigate their effects on plant oxidative stress and antioxidant activities. As previously characterized, the inoculation of PGPB and PGIB strains accelerated and reduced the growth of L. minor, respectively. After 4 and 8 days of cultivation, compared to the PGPB strains, the PGIB strains induced larger amounts of O 2 •- , H 2 O 2 , and malondialdehyde (MDA) in duckweed, although all bacterial strains consistently increased O 2 •- content by two times more than that in the aseptic control plants. Activities of five antioxidant enzymes were also elevated by the inoculation of PGIB, confirming the severe oxidative stress condition in plants. These results suggest that the surface attached bacteria affect differently on host oxidative stress and its response, which degree correlates negatively to their effects on plant growth. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  8. Modelling and predicting the simultaneous growth of Escherichia coli and lactic acid bacteria in milk.

    Science.gov (United States)

    Ačai, P; Valík, L'; Medved'ová, A; Rosskopf, F

    2016-09-01

    Modelling and predicting the simultaneous competitive growth of Escherichia coli and starter culture of lactic acid bacteria (Fresco 1010, Chr. Hansen, Hørsholm, Denmark) was studied in milk at different temperatures and Fresco inoculum concentrations. The lactic acid bacteria (LAB) were able to induce an early stationary state in E. coli The developed model described and tested the growth inhibition of E. coli (with initial inoculum concentration 10(3) CFU/mL) when LAB have reached maximum density in different conditions of temperature (ranging from 12 ℃ to 30 ℃) and for various inoculum sizes of LAB (ranging from approximately 10(3) to 10(7) CFU/mL). The prediction ability of the microbial competition model (the Baranyi and Roberts model coupled with the Gimenez and Dalgaard model) was first performed only with parameters estimated from individual growth of E. coli and the LAB and then with the introduced competition coefficients evaluated from co-culture growth of E. coli and LAB in milk. Both the results and their statistical indices showed that the model with incorporated average values of competition coefficients improved the prediction of E. coli behaviour in co-culture with LAB. © The Author(s) 2015.

  9. Corrosion inhibition of carbon steel by an amine- fatty acid in acidic ...

    African Journals Online (AJOL)

    The corrosion inhibition of carbon steel in 3% de-aerated NaCl acidic solution with amine–fatty acid corrosion inhibitor, KI384, was investigated at different temperatures using potentiodynamic polarization technique. The Corrosion rate was calculated in the presence and absence of inhibitor. The inhibition increased with ...

  10. Decreased sugar concentration in vegetable and fruit juices by growth of functional lactic acid bacteria.

    Science.gov (United States)

    Ishii, Masaki; Matsumoto, Yasuhiko; Nishida, Satoshi; Sekimizu, Kazuhisa

    2017-03-22

    Leuconostoc carnosum #7-2, L. gelidum #4-2, and L. mesenteroides 8/11-3, which were isolated from fermented plant foods, are lactic acid bacteria. We previously reported that these bacteria are functional lactic acid bacteria whose innate immunity-stimulating activities are high based on a silkworm muscle contraction assay. The concentrations of these three lactic acid bacteria increased to more than 1 × 10 6 colony forming units (cfu)/mL in various vegetable and fruit juices when the pH values were appropriately adjusted. As the bacteria grew in the vegetable and fruit juices, the pH decreased and the concentrations of total sugars and glucose also decreased. These findings suggest that these functional lactic acid bacteria can be used to produce vegetable and fruit juices with reduced sugar levels, which is expected to be beneficial for human health.

  11. Electron transport chains of lactic acid bacteria - walking on crutches is part of their lifestyle

    Science.gov (United States)

    Brooijmans, Rob; Hugenholtz, Jeroen

    2009-01-01

    A variety of lactic acid bacteria contain rudimentary electron transport chains that can be reconstituted by the addition of heme and menaquinone to the growth medium. These activated electron transport chains lead to higher biomass production and increased robustness, which is beneficial for industrial applications, but a major concern when dealing with pathogenic lactic acid bacteria. PMID:20948651

  12. Human milk is a source of lactic acid bacteria for the infant gut.

    Science.gov (United States)

    Martín, Rocío; Langa, Susana; Reviriego, Carlota; Jimínez, Esther; Marín, María L; Xaus, Jordi; Fernández, Leonides; Rodríguez, Juan M

    2003-12-01

    To investigate whether human breast milk contains potentially probiotic lactic acid bacteria, and therefore, whether it can be considered a synbiotic food. Study design Lactic acid bacteria were isolated from milk, mammary areola, and breast skin of eight healthy mothers and oral swabs and feces of their respective breast-fed infants. Some isolates (178 from each mother and newborn pair) were randomly selected and submitted to randomly amplified polymorphic DNA (RAPD) polymerase chain reaction analysis, and those that displayed identical RAPD patterns were identified by 16S rDNA sequencing. Within each mother and newborn pair, some rod-shaped lactic acid bacteria isolated from mammary areola, breast milk, and infant oral swabs and feces displayed identical RAPD profiles. All of them, independently from the mother and child pair, were identified as Lactobacillus gasseri. Similarly, among coccoid lactic acid bacteria from these different sources, some shared an identical RAPD pattern and were identified as Enterococcus faecium. In contrast, none of the lactic acid bacteria isolated from breast skin shared RAPD profiles with lactic acid bacteria of the other sources. Breast-feeding can be a significant source of lactic acid bacteria to the infant gut. Lactic acid bacteria present in milk may have an endogenous origin and may not be the result of contamination from the surrounding breast skin.

  13. Evaluation of Ellagic acid on the activities of oral bacteria with the ...

    African Journals Online (AJOL)

    USER

    2010-06-21

    Jun 21, 2010 ... water-insoluble glucan generated by oral bacteria. The numbers of 3H-thymidine labeled bacteria attached to S-HA was counted by scintillation counting method. Sprague Dawley rats were orally fed with 0.5mg/mL ellagic acid for 28 days and their behaviours and excretions were monitored. Ellagic acid.

  14. Omeprazole Inhibits Acetylsalicylic Acid-Modified Histamine Stimulation of Acid Secretion in Rabbit Gastric Glands

    Directory of Open Access Journals (Sweden)

    Daniel T Brosseuk

    1994-01-01

    Full Text Available The effects of misoprostol and omeprazole on basal-, histamine- and acetylsalicylic acid (ASA-induced gastric acid secretion by isolated rabbit gastric glands were studied. The authors found that ASA at a concentration of 2.4×10-3 M significantly inhibited acid secretion in the isolated gastric glands to 65% of basal levels, and that ASA at a concentration of 2.4×l0-2 M significantly inhibited the histamine stimulation of acid secretion to 78% of maximal. Misoprostol inhibited acid secretion to 76% of basal acid secretion, while omeprazole inhibited secretion to 58% of basal values. Misoprostol inhibited the ASA-modified histamine stimulation to 82% of maximal stimulation. In contrast, omeprazole was able to inhibit the ASA-modified histamine stimulation to 48% of maximal. This omeprazole inhibition of secretagogue-induced acid production reduced acid secretion to levels below basal secretion, indicating that neither histamine nor ASA (at the concentrations used, alone or in combination, had any stimulatory effect in the presence of omeprazole. Misoprostol is the recommended drug of choice for prevention and treatment of nonsteroidal anti-inflammatory drug (NSAID-induced gastrointestinal mucosal injury. In vitro results suggest that omeprazole appears to treat this condition more effectively if gastric acid secretion is a necessary prerequisite for NSAID-induced mucosal injury.

  15. Toxicity reduction of ochratoxin A by lactic acid bacteria.

    Science.gov (United States)

    Luz, C; Ferrer, J; Mañes, J; Meca, G

    2018-02-01

    Ochratoxin A (OTA) is a mycotoxin produced by the metabolism of fungus belonging to the genus Aspergillus and Penicillium. In this paper we report, the capacity of different cultures of lactic acid bacteria (LAB) to degrade OTA present in MRS broth at both pH 3.5 and 6.5. A study of OTA reduction during gastrointestinal digestion carried out with the LAB was also performed. Taking into account the two reduction mechanisms of OTA studied in this work as the enzymatic one and the adsorption on the cell wall, as well as at pH 3.5 and 6.5 the reduction values of OTA were in a range of 30-99%, being the strains with greater reduction (97% and 95%) Lb. rhamnosus CECT 278T and Lb. plantarum CECT 749 respectively. In the experiments carried out digesting the OTA in MRS medium with LAB, the highest bioaccessibility reduction was observed by the strain of Lb. johnsonii CECT 289, showing a mean reduction around all the gastrointestinal digestion process of 97.4%. The mass spectrometry associated to the linear ion trap method identified ochratoxin alpha (OTα) m/z = 256.1 and phenylalanine (Phe) m/z = 166.1 as the major metabolites of OTA degradation in LAB cultures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Isolation and characterisation of lactic acid bacteria from donkey milk.

    Science.gov (United States)

    Soto Del Rio, Maria de Los Dolores; Andrighetto, Christian; Dalmasso, Alessandra; Lombardi, Angiolella; Civera, Tiziana; Bottero, Maria Teresa

    2016-08-01

    During the last years the interest in donkey milk has increased significantly mainly because of its compelling functional elements. Even if the composition and nutritional properties of donkey milk are known, its microbiota is less studied. This Research Communication aimed to provide a comprehensive characterisation of the lactic acid bacteria in raw donkey milk. RAPD-PCR assay combined with 16S rDNA sequencing analysis were used to describe the microbial diversity of several donkey farms in the North West part of Italy. The more frequently detected species were: Lactobacillus paracasei, Lactococcus lactis and Carnobacterium maltaromaticum. Less abundant genera were Leuconostoc, Enterococcus and Streptococcus. The yeast Kluyveromyces marxianus was also isolated. The bacterial and biotype distribution notably diverged among the farms. Several of the found species, not previously detected in donkey milk, could have an important probiotic activity and biotechnological potential. This study represents an important insight to the ample diversity of the microorganisms present in the highly selective ecosystem of raw donkey milk.

  17. Optimization of β-galactosidase production from lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Carević Milica

    2015-01-01

    Full Text Available β-galactosidase, commonly known as lactase, represents commercially important enzyme that is prevalently used for lactose hydrolysis in milk and whey. To the date, it has been isolated from various sources. In this study different strains of lactic acid bacteria were assessed for their β-galactosidase productivity, and Lactobacillus acidophilus ATCC 4356 resulted with the highest production potential. Thereafter, optimal conditions for accomplishing high yields of β-galactosidase activity were determined. Maximal specific activity (1.01 IU mL-1 was accomplished after 2 days shake flask culture fermentation (150 rpm at 37ºC, with modified Man Rogosa Sharpe culture broth using lactose (2.5% as sole carbon source. Finally, in order to intensify release of intracellular β-galactosidase different mechanical and chemical methods were conducted. Nevertheless, vortexing with quartz sand (150 μm as abrasive was proven to be the most efficient method of cell disruption. The optimum temperature of obtained β-galactosidase was 45°C and the optimum range pH 6.5-7.5.

  18. A metabolic pathway for catabolizing levulinic acid in bacteria

    International Nuclear Information System (INIS)

    Rand, Jacqueline M.; Pisithkul, Tippapha; Clark, Ryan L.; Thiede, Joshua M.; Mehrer, Christopher R.

    2017-01-01

    Microorganisms can catabolize a wide range of organic compounds and therefore have the potential to perform many industrially relevant bioconversions. One barrier to realizing the potential of biorefining strategies lies in our incomplete knowledge of metabolic pathways, including those that can be used to assimilate naturally abundant or easily generated feedstocks. For instance, levulinic acid (LA) is a carbon source that is readily obtainable as a dehydration product of lignocellulosic biomass and can serve as the sole carbon source for some bacteria. Yet, the genetics and structure of LA catabolism have remained unknown. Here, we report the identification and characterization of a seven-gene operon that enables LA catabolism in Pseudomonas putida KT2440. When the pathway was reconstituted with purified proteins, we observed the formation of four acyl-CoA intermediates, including a unique 4-phosphovaleryl-CoA and the previously observed 3-hydroxyvaleryl-CoA product. Using adaptive evolution, we obtained a mutant of Escherichia coli LS5218 with functional deletions of fadE and atoC that was capable of robust growth on LA when it expressed the five enzymes from the P. putida operon. Here, this discovery will enable more efficient use of biomass hydrolysates and metabolic engineering to develop bioconversions using LA as a feedstock.

  19. Removal of Paralytic Shellfish Toxins by Probiotic Lactic Acid Bacteria

    Directory of Open Access Journals (Sweden)

    Mari Vasama

    2014-07-01

    Full Text Available Paralytic shellfish toxins (PSTs are non-protein neurotoxins produced by saltwater dinoflagellates and freshwater cyanobacteria. The ability of Lactobacillus rhamnosus strains GG and LC-705 (in viable and non-viable forms to remove PSTs (saxitoxin (STX, neosaxitoxin (neoSTX, gonyautoxins 2 and 3 (GTX2/3, C-toxins 1 and 2 (C1/2 from neutral and acidic solution (pH 7.3 and 2 was examined using HPLC. Binding decreased in the order of STX ~ neoSTX > C2 > GTX3 > GTX2 > C1. Removal of STX and neoSTX (77%–97.2% was significantly greater than removal of GTX3 and C2 (33.3%–49.7%. There were no significant differences in toxin removal capacity between viable and non-viable forms of lactobacilli, which suggested that binding rather than metabolism is the mechanism of the removal of toxins. In general, binding was not affected by the presence of other organic molecules in solution. Importantly, this is the first study to demonstrate the ability of specific probiotic lactic bacteria to remove PSTs, particularly the most toxic PST-STX, from solution. Further, these results warrant thorough screening and assessment of safe and beneficial microbes for their usefulness in the seafood and water industries and their effectiveness in vivo.

  20. Modification of azo dyes by lactic acid bacteria.

    Science.gov (United States)

    Pérez-Díaz, I M; McFeeters, R F

    2009-08-01

    The ability of Lactobacillus casei and Lactobacillus paracasei to modify the azo dye, tartrazine, was recently documented as the result of the investigation on red coloured spoilage in acidified cucumbers. Fourteen other lactic acid bacteria (LAB) were screened for their capability to modify the food colouring tartrazine and other azo dyes of relevance for the textile industry. Most LAB modified tartrazine under anaerobic conditions, but not under aerobic conditions in modified chemically defined media. Microbial growth was not affected by the presence of the azo dyes in the culture medium. The product of the tartrazine modification by LAB was identified as a molecule 111 daltons larger than its precursor by liquid chromatography-mass spectrometry. This product had a purple colour under aerobic conditions and was colourless under anaerobic conditions. It absorbed light at 361 and 553 nm. LAB are capable of anabolizing azo dyes only under anaerobic conditions. IMPACT AND SIGNIFICANCE OF THE STUDY: Although micro-organisms capable of reducing the azo bond on multiple dyes have been known for decades, this is the first report of anabolism of azo dyes by food related micro-organisms, such as LAB.

  1. Antimicrobial Activity of Cell Free Supernatant of Irradiated Lactic Acid Bacteria Isolates

    International Nuclear Information System (INIS)

    Abdelaleem, M.A.; AL-Hagar, O.E.Aa.

    2015-01-01

    Attempts were made to isolate bio preservatives using food wastes with no value and low cost. Whey is the raw material achieved that value. Whey and many other food wastes are used in our study to isolate Lactic acid bacteria (LAB). Cell free supernatants (CFS) of isolates are used to evaluate their antimicrobial activity against indicator pathogenic bacterial strains. CFS-9 isolate from whey has the highest inhibitory activity compared to all other isolates. The inhibitory activity of CFS-9, Nisin (400 IU / ml) and the standard Lactococcus Lactis Subsp. Lactis ATCC 11454 (Lacto) were determined. Furthermore, isolate-9 and Lacto strains were exposed to irradiation at different doses. The inhibition zones of; control isolate-9 (non-irradiated) showed the highest values against all indicator strains, CFS of irradiated Lacto at dose 250 Gy was the highest value against Bacillus cereus and Escherichia coli compared to other irradiation treatments, CFS of irradiated Lacto at dose 100 Gy was the highest value against Staph aureus, while the inhibition zone was in the highest value in CFS of irradiated Lacto at dose 500 Gy against Salmonella typhimurium. Nisin (400 IU / ml) was significantly higher than all CFS of irradiated isolate-9 while, the inhibition zones of all CFS-Lacto (irradiated and nonirradiated) are better and higher than nisin-400

  2. Autoinducer-2 properties of kimchi are associated with lactic acid bacteria involved in its fermentation.

    Science.gov (United States)

    Park, Hyunjoon; Shin, Heuynkil; Lee, Kyuyeon; Holzapfel, Wilhelm

    2016-05-16

    Bacteria use the cell density-dependent quorum signalling system to regulate particular gene expressions. In food microbiology, signalling is well known for its relation to (foodborne) pathogenicity, food spoilage, and biofilm formation. Quorum quenching and inhibition are thus being considered as a feasible approach in food preservation and safety. In the case of the luxS-mediated universal quorum sensing using autoinducer-2 (AI-2), however, it could be a different issue. Several studies have reported a luxS AI-2 synthase homologue in numerous bacteria, comprising both pathogens and beneficial strains. A recent study has shown the AI-2 signal to restore the balance of the major phyla of the gut microbiota in antibiotic-induced dysbiosis. We measured the AI-2 activity of the lactic fermented food, kimchi, and found different AI-2 signalling intensities. In order to trace the origin of the signal production, we obtained 229 lactic acid bacterial isolates from the kimchi samples, and detected the AI-2 properties of each isolate using a modified AI-2 bioluminescence assay. Our results showed isolates of dominant species of the genera Lactobacillus, Weissella and Leuconostoc which either produced or inhibited the AI-2 signal. No isolate of the dominant species Lactobacillus sakei (75 isolates) and Lactobacillus curvatus (28 isolates) showed AI-2 producing activity, while AI-2 inhibition could not be detected for any of the 31 Lactobacillus plantarum isolates. These results suggest the AI-2 activity of kimchi to result from the interaction of the associated microbial food cultures (MFCs) during fermentation. Thus far, only sparse information is available on AI-2 signalling interaction in fermented food, however, we suggest that fermented food may be a supplier of AI-2 signalling molecules via typical MFCs. Copyright © 2016. Published by Elsevier B.V.

  3. Antibacterial activity and optimisation of bacteriocin producing lactic acid bacteria isolated from beef (red meat) samples

    International Nuclear Information System (INIS)

    Ali, N.M.; Mazhar, B.; Khadija, I.; Kalim, B.

    2016-01-01

    Bacteriocin producing bacteria are commonly found in meat products to enhance their shelf-life. In the present study, bacterial species were isolated from meat samples (beef) from different localities of Lahore, Pakistan. MRS agar medium was used to isolate lactic acid bacteria (LAB) through spread and streak methods (incubated for 72 h at 37 degree C). Identification of bacteriocinogenic LAB strains was done by using staining techniques, morphology based characteristics and biochemical tests. These strains were BSH 1b, BSH 3a, BIP 4a, BIP 3a, BIP 1b and BRR 3a. Antibacterial activity of LAB was performed against food borne pathogens viz., Escherichia coli and Staphylococcus aureus through paper disc diffusion method. Three bacterial strains showed maximum inhibition and characterised by ribotyping viz., BIP 4a was identified as Lactobacillus curvatures, BIP 3a was Staphylococcus warneri and BIP 1b was Lactobacillus graminis . Optimum pH 5-6.5 and 30-37 degree C temperature for isolated bacterial strains was recorded. Protein concentration measured was 0.07 mg/mL for BSH 1b, 0.065 mg/mL for BSH 3a, 0.057 mg/mL for BIP 4a, 0.062 mg/mL for BIP 1b, 0.065 mg/mL for BIP 3a and for BRR 3a 0.078 mg/mL, respectively. Bacteriocin of all isolates except BIP 3a was found to be sensitive towards pepsin and resistant towards Rnase. Bacteriocin production was stable at between pH 5.0 and 6.0 and resistant temperature was 40 degree C. It was concluded that lactic acid bacteria (LAB) from meat can be helpful as antibacterial agents against food-borne bacterial pathogens because of thermostable producing bacteriocin. (author)

  4. Antimicrobial Activity – The Most Important Property of Probiotic and Starter Lactic Acid Bacteria

    Directory of Open Access Journals (Sweden)

    Blaženka Kos

    2010-01-01

    Full Text Available The antimicrobial activity of industrially important lactic acid bacteria as starter cultures and probiotic bacteria is the main subject of this review. This activity has been attributed to the production of metabolites such as organic acids (lactic and acetic acid, hydrogen peroxide, ethanol, diacetyl, acetaldehyde, acetoine, carbon dioxide, reuterin, reutericyclin and bacteriocins. The potential of using bacteriocins of lactic acid bacteria, primarily used as biopreservatives, represents a perspective, alternative antimicrobial strategy for continuously increasing problem with antibiotic resistance. Another strategy in resolving this problem is an application of probiotics for different gastrointestinal and urogenital infection therapies.

  5. Examination of Lactic Acid Bacteria to Secretion of Bacteriocins

    Directory of Open Access Journals (Sweden)

    Maira Urazova

    2014-01-01

    Full Text Available Introduction: Bacteriocins produced by lactic acid bacteria (LAB have the potential to cover a very broad field of applications, including the food industry and the medical sector. In the food industry, bacteriocinogenic LAB strains can be used as starter cultures, co-cultures, and bioprotective cultures, which would be used to improve food quality and safety. In the medical sector, bacteriocins of probiotic LAB might play a role in interactions, which take place in human gastrointestinal tract, and contribute to gut health. The aim of this study was the examine the effect of LAB antimicrobial activity. Methods: LAB were isolated from different commercial and home made products, such as kazy and sour cream. To screen for bacteriocin producing LAB, we used an agar diffusion bioassay, described in a previous study by Dr. Yang, with three modifications in cell-free supernatant (CFS. First we had a clear supernatant, second we adjusted the CFS to pH 6.0 to eliminate acids antimicrobial effects, and third the CFS pH 6.0 was treated with catalase to exclude the action of H2O2 and confirm action of bacteriocin-like substances. Pathogenic S.marcescens, E. coli, S.aureus cultures were used as indicators. Results: Screening of 95 strains of LAB through deferred antagonism to six indicator cultures showed that all of the selected strains had a high value of antibacterial activity. However, CFS of only 50 strains retained their antimicrobial activity, and 10 of them lost this activity in the second modification of CFS with pH 6.0 to test culture S.marcescens, which confirmed the acidic nature of antimicrobial activity of CFS. Lb.rhamnosus (P-1, Lb.fermentum (N-6, and Lc.lactis (7M lost antibacterial activity in the presence of the catalase. All modifications of CFS of three strains: Lb.pentosus (16al, Lb.pentosus (P-2, and Pediococcusacidilactici (8 retained inhibitory activity to E.coli and S. aureus. Supernatants of only Lactococcusgarvieae (10a and

  6. INHIBITION OF PATHOGENS BY SPOROGENIC BACTERIA ISOLATED FROM HONEY OF Melipona sp. (APIDAE: APINAE: MELIPONINI

    Directory of Open Access Journals (Sweden)

    KELY DAMIANA NOVAES DA SILVA

    2016-01-01

    Full Text Available The aim of this study was to isolate sporogenic bacteria from the honey of stingless bees Melipona sp., in dry forest, and to evaluate their antagonistic potential for medicinal employment purposes and animal production. The honey samples were collected in Serra Talhada - PE, where honey was taken from four different hives (in triplicate, totaling 12 samples. The samples were diluted and subjected to 80 ºC for 20 minutes to eliminate vegetative cells. The dilutions were plated onto nutrient agar and incubated at 30 ºC for 72 hours. Then the colony forming units (CFU were quantified. The samples were also plated onto malt agar and Sabouraud agar, and incubated at 30 ºC for 14 days for the growth of yeast and molds. Total and fecal coliforms were quantified by the most probable number method (MPN. Seven isolates (I of sporogenic bacteria ( Bacillus were obtained, however only four showed probiotic potential. Isolate I - 5 showed the greatest probiotic potential and inhibited the growth of Escherichia coli , Klebsiella sp., Pseudomonas aeruginosa, Salmonella sp., and Staphylococcus aureus . The growth of the Sarcina sp. was not inhibited by any isolate. No yeast, molds or coliforms were found. The Melipona sp. honey is a source of spore - forming bacteria and is antagonistic to microorganisms that contaminate honey. It has good microbiological quality.

  7. Production of γ-Amino Butyric Acid in Tea Leaves wit Treatment of Lactic Acid Bacteria

    Science.gov (United States)

    Watanabe, Yuko; Hayakawa, Kiyoshi; Ueno, Hiroshi

    Lactic acid bacteria was searched for producing termented tea that contained a lot of γ-amino butyric acid(GABA). Also examined were the growth condition, GABA production and changes in catechin contents in the tea leaves. Lactobacillus brevis L12 was found to be suitable for the production of fermented tea since it gave as much GABA as gabaron tea when tea leaves being suspended with water at 10% and incubated for 4 days at 25°C. The amount of GABA produced was more than calculated based upon the content of glutamic acid in tea leaves. It is probable to assume that glutamate derived from glutamine and theanine is converted into GABA.

  8. Lactic acid bacteria: promising supplements for enhancing the biological activities of kombucha.

    Science.gov (United States)

    Nguyen, Nguyen Khoi; Dong, Ngan Thi Ngoc; Nguyen, Huong Thuy; Le, Phu Hong

    2015-01-01

    Kombucha is sweetened black tea that is fermented by a symbiosis of bacteria and yeast embedded within a cellulose membrane. It is considered a health drink in many countries because it is a rich source of vitamins and may have other health benefits. It has previously been reported that adding lactic acid bacteria (Lactobacillus) strains to kombucha can enhance its biological functions, but in that study only lactic acid bacteria isolated from kefir grains were tested. There are many other natural sources of lactic acid bacteria. In this study, we examined the effects of lactic acid bacteria from various fermented Vietnamese food sources (pickled cabbage, kefir and kombucha) on kombucha's three main biological functions: glucuronic acid production, antibacterial activity and antioxidant ability. Glucuronic acid production was determined by high-performance liquid chromatography-mass spectrometry, antibacterial activity was assessed by the agar-well diffusion method and antioxidant ability was evaluated by determining the 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity. Four strains of food-borne pathogenic bacteria were used in our antibacterial experiments: Listeria monocytogenes ATCC 19111, Escherichia coli ATCC 8739, Salmonella typhimurium ATCC 14028 and Bacillus cereus ATCC 11778. Our findings showed that lactic acid bacteria strains isolated from kefir are superior to those from other sources for improving glucuronic acid production and enhancing the antibacterial and antioxidant activities of kombucha. This study illustrates the potential of Lactobacillus casei and Lactobacillus plantarum isolated from kefir as biosupplements for enhancing the bioactivities of kombucha.

  9. Engineering strategies aimed at control of acidification rate of lactic acid bacteria

    DEFF Research Database (Denmark)

    Martinussen, Jan; Solem, Christian; Holm, Anders Koefoed

    2013-01-01

    The ability of lactic acid bacteria to produce lactic acid from various sugars plays an important role in food fermentations. Lactic acid is derived from pyruvate, the end product of glycolysis and thus a fast lactic acid production rate requires a high glycolytic flux. In addition to lactic acid...... fermentation processes, but also for novel applications of lactic acid bacteria, such as cell factories for the production of green fuels and chemicals. With respect to the control and regulation of the fermentation mode, some progress has been made, but the question of which component(s) control the main...

  10. Mechanism of acid corrosion inhibition using magnetic nanofluid

    Science.gov (United States)

    Parekh, Kinnari; Jauhari, Smita; Upadhyay, R. V.

    2016-12-01

    The inhibition effect of magnetic nanofluid on carbon steel in acid solutions was investigated using gravimetric, potentiodynamic and SEM measurement. The inhibition efficiency increases up to 95% and 75% for 51.7 mM concentration, respectively, in 1 M HCl and 1 M H2SO4 medium. The adsorption of nanoparticles to the steel surface forms a barrier between the metal and the aggressive environment, which is responsible for observed inhibition action. The adsorption of nanoparticles on steel surface is supported by the Langmuir and Freundlich adsorption isotherm and surface morphology scanned through SEM.

  11. Use of agar diffusion assay to evaluate bactericidal activity of formulations of alkaline salts of fatty acids against bacteria associated with poultry processing

    Science.gov (United States)

    The agar diffusion assay was used to examine antibacterial activity of alkaline salts of fatty acids (FA). Wells in agar media seeded with bacteria were filled with FA-potassium hydroxide (KOH) solutions, plates were incubated, and zones of inhibition were measured. The relationship between bacteric...

  12. Inhibiting Effect of Nicotinic Acid Hydrazide on Corrosion of Aluminum and Mild Steel in Acidic Medium

    International Nuclear Information System (INIS)

    Bhat, J. Ishwara; Alva, Vijaya D. P.

    2014-01-01

    The corrosion behavior of aluminum and mild steel in hydrochloric acid medium was studied using a nicotinic acid hydrazide as inhibitor by potentiodynamic polarization, electrochemical impedance spectroscopy technique and gravimetric methods. The effects of inhibitor concentration and temperature were investigated. The experimental results suggested, nicotinic acid hydrazide is a good corrosion inhibitor for both aluminum and mild steel in hydrochloric acid medium and the inhibition efficiency increased with increase in the inhibitor concentration. The polarization studies revealed that nicotinic acid hydrazide exhibits mixed type of inhibition. The inhibition was assumed to occur via adsorption of the inhibitor molecules on the aluminum and mild steel surface and inhibits corrosion by blocking the reaction sites on the surface of aluminum

  13. Acid-regulated proteins induced by Streptococcus mutans and other oral bacteria during acid shock.

    Science.gov (United States)

    Hamilton, I R; Svensäter, G

    1998-10-01

    Our previous research has demonstrated that with the more aciduric oral bacteria, an acid shock to sub-lethal pH values results in the induction of an acid tolerance response that protects the cells at extremely low pH (pH 3.0-4.0) that kills unadapted control cells maintained at pH 7.5 (Oral Microbiol Immunol 1997: 12: 266-273). In this study, we were interested in comparing the protein profiles of acid-shocked and control cells of nine organisms from three acid-ogenic genera that could be categorized as strong, weak and non-acid responders in an attempt to identify proteins that could be classified as acid-regulated proteins and which may be important in the process of survival at very low pH. For this, log-phase cultures were rapidly acidified from pH 7.5 to 5.5 in the presence of [14C]-amino acids for varying periods up to 2 h, the period previously shown to be required for maximum induction of the acid response. The cells were extracted for total protein and subjected to one-dimensional sodium dodecyl sulfate-polyacrylamide chromatography with comparable control and acid-shocked protein profiles compared by scanning and computer analysis. Of particular interest were the proteins in the acid-shocked cells that showed enhanced labeling (i.e., synthesis) over the control cells, since these were considered acid-regulated proteins of importance in pH homeostasis. Streptococcus mutans LT11 generated the most rapid and complex pattern: a total of 36 acid-regulated proteins showing enhanced synthesis, with 25 appearing within the first 30 min of acid shock. The enhanced synthesis was transient with all proteins, with the exception of two with molecular weights of 50/49 and 33/32 kDa. Within the acid-regulated proteins were proteins having molecular weights comparable to the heat shock proteins and the various subunits of the membrane H+/ATPase. By comparison, the strong responder, Lactobacillus casei 151, showed the enhanced formation of only nine proteins within the

  14. Who will win the race in childrens' oral cavities? Streptococcus mutans or beneficial lactic acid bacteria?

    Science.gov (United States)

    Güngör, Ö E; Kırzıoğlu, Z; Dinçer, E; Kıvanç, M

    2013-09-01

    Adhesion to oral soft and hard tissue is crucial for bacterial colonisation in the mouth. The aim of this work was to select strains of oral lactic acid bacteria that could be used as probiotics for oral health. To this end, the adhesive properties of some lactic acid bacteria were investigated. Seventeen lactic acid bacteria including two Streptococcus mutans strains were isolated from the oral cavity of healthy children, while other strains were isolated from fermented meat products. The bacterial strains were applied to teeth surfaces covered with saliva or without saliva. A significant diversity in adhesion capacity to teeth surfaces among the lactic acid bacteria was observed. Lactic acid bacteria isolated from the oral cavity adhered the best to teeth surfaces covered with saliva, whereas lactic acid bacteria isolated from fermented meat samples adhered the best to tooth surface without saliva. All strains of lactic acid bacteria were able to reduce the number of S. mutans cells, in particular on saliva-coated tooth surface. Therefore, they might have potential as probiotics for the oral cavity.

  15. Systems biology of lactic acid bacteria: a critical review.

    Science.gov (United States)

    Teusink, Bas; Bachmann, Herwig; Molenaar, Douwe

    2011-08-30

    Understanding the properties of a system as emerging from the interaction of well described parts is the most important goal of Systems Biology. Although in the practice of Lactic Acid Bacteria (LAB) physiology we most often think of the parts as the proteins and metabolites, a wider interpretation of what a part is can be useful. For example, different strains or species can be the parts of a community, or we could study only the chemical reactions as the parts of metabolism (and forgetting about the enzymes that catalyze them), as is done in flux balance analysis. As long as we have some understanding of the properties of these parts, we can investigate whether their interaction leads to novel or unanticipated behaviour of the system that they constitute. There has been a tendency in the Systems Biology community to think that the collection and integration of data should continue ad infinitum, or that we will otherwise not be able to understand the systems that we study in their details. However, it may sometimes be useful to take a step back and consider whether the knowledge that we already have may not explain the system behaviour that we find so intriguing. Reasoning about systems can be difficult, and may require the application of mathematical techniques. The reward is sometimes the realization of unexpected conclusions, or in the worst case, that we still do not know enough details of the parts, or of the interactions between them. We will discuss a number of cases, with a focus on LAB-related work, where a typical systems approach has brought new knowledge or perspective, often counterintuitive, and clashing with conclusions from simpler approaches. Also novel types of testable hypotheses may be generated by the systems approach, which we will illustrate. Finally we will give an outlook on the fields of research where the systems approach may point the way for the near future.

  16. Resistance to antibiotics in Lacid acid bacteria - strain Lactococcus

    Directory of Open Access Journals (Sweden)

    Filipić Brankica

    2015-01-01

    Full Text Available Lactic acid bacteria (LAB are widely used in the food industry, especially in the production of fermented dairy products and meat. The most studied species among Lis Lactococcus lactis. L. lactis strains are of great importance in the production of fermented dairy products such as yogurt, butter, fresh cheese and some kind of semi-hard cheese. Although L. lactis acquired the „Generally Regarded As Safe“ (GRAS status, many investigations indicated that lactococci may act as reservoirs of antibiotic resistance genes, which could be transferred to other bacterial species in human gastrointestinal tract includ­ing pathogens. The genome analysis of L. lactis indicated the presence of at least 40 putative drug transporter genes, and only four multidrug resistance (MDR transporters are functionally characterized: LmrA, LmrP, LmrCD i CmbT. LmrA is the first described MDR transporter in prokaryotes. LmrCD is responsible for resistance to cholate, which is an integral part of human bile and LmrCD is important for intestinal survival of lactococci that are used as probiotics. Secondary multidrug transporter LmrP confers resistance to lincosamides, macrolides, streptogramins and tetracyclines. CmbT protein has an effect on the host cell resistance to lincomycin, sulfadiazine, streptomycin, rifampicin, puromycin and sulfametox­azole. Since the food chain is an important way of transmitting resistance genes in human and animal population, it is of great importance to study the mechanisms of resistance in lactococci and other LAB, intended for the food industry. [Projekat Ministarstva nauke Republike Srbije, br. 173019: Izučavanje gena i molekularnih mehanizama u osnovi probiotičke aktivnosti bakterija mlečne kiseline izolovanih sa područja Zapadnog Balkana

  17. Selection of Lactic Acid Bacteria as Probiotic Candidate for Chicken

    Directory of Open Access Journals (Sweden)

    F. Hamida

    2015-08-01

    Full Text Available Lactic acid bacteria (LAB regarded as safe microorganisms; they can naturally live in gastrointestinal tract, so appropriately used as a probiotic for chicken. This study aimed to select six isolates of LAB (E1223, E3, E4, E5, E7, and E8 to obtain the isolates potentially as probiotic candidate for chicken. The six isolates were derived from spontaneous fermented corn obtained from Laboratory of Animal Biotechnology and Biomedical, PPSHB, Bogor Agricultural University, Indonesia. LAB isolates were tested their susceptibility to antibiotics (bambermycin, erythromycin, chloramphenicol, and tetracycline then were examined in vitro for their tolerance to gastrointestinal pH (2, 3, 4, and 7.2 and 0.5% bile salt condition, antimicrobial activity against Salmonella enteritidis and Enterococcus casseliflavus, and ability to adhere to chicken ileal cells. The results showed the isolates E5, E7, and E8 were sensitive to tetracycline and chloramphenicol, they could survive at pH 2, 3, 4, and 7.2, could survive at 0.5% bile salts, produced antimicrobial activity, and able to adhere to ileal cells (9.40±0.00 Log CFU/cm2 of E8 and were significantly (P<0.05 higher than those of control (5.30±0.14 Log CFU/cm2. In conclusion, this study showed that isolate E8 had better potential compared to isolates E5 and E7 in most in vitro assays as a probiotic candidate for chicken. E5, E7, and E8 were closely related with Pediococcus pentosaceus based on 16S rRNA gene.

  18. Antimicrobial properties of lactic acid bacteria isolated from traditional yogurt and milk against Shigella strains.

    Science.gov (United States)

    Zare Mirzaei, Elnaze; Lashani, Elahe; Davoodabadi, Abolfazl

    2018-01-01

    Background: Lactic acid bacteria (LAB) are normal flora of the mouth, intestines and the female genital tract. They are also frequently found in meat, vegetables, and dairy products. Most of probiotic bacteria belong to the LAB group. Some probiotic LAB are useful in prevention and treatment of diarrheal diseases. The aim of this study was to investigate the antimicrobial properties of LAB isolated from traditional yogurt and milk against Shigella strains. Materials and methods: Forty LAB strains were isolated from traditional yogurt and milk. The antimicrobial activity of LAB against Shigella strains (eight S. flexneri , four S. sonnei ) was examined using the agar-well diffusion assay. LAB strains with antimicrobial effect against all Shigella strains were identified by 16S rRNA gene sequencing. Results: Six LAB strains inhibited the growth of all 12 Shigella strains. Lb. paracasei Y1-3, Lb. paracasei Y8-1 and Lb. fermentum Y2-2 were isolated from yogurt. Lb. paracasei M18-1, Lb. parelimentarius M4-3 and Lb. plantarum M19-1 were isolated from milk. Conclusion: This study showed that Lactobacillus strains with good inhibitory activity against S. flexneri and S. sonnei could be isolated from traditional yogurt and milk.

  19. Glycation inhibits trichloroacetic acid (TCA)-induced whey protein precipitation

    Science.gov (United States)

    Four different WPI saccharide conjugates were successfully prepared to test whether glycation could inhibit WPI precipitation induced by trichloroacetic acid (TCA). Conjugates molecular weights after glycation were analyzed with SDS-PAGE. No significant secondary structure change due to glycation wa...

  20. Inhibition of nuclear T3 binding by fatty acids

    NARCIS (Netherlands)

    Wiersinga, W. M.; Chopra, I. J.; Teco, G. N.

    1988-01-01

    Studies were performed to evaluate a possible modulatory role of lipids on the binding of T3 to rat liver nuclear receptors in vitro. Unsaturated fatty acids were potent inhibitors of the binding of [125I] T3 to isolated rat liver nuclei. Doses (in mumol/L) causing a 50% inhibition of nuclear T3

  1. Phosphatidic acid inhibits ceramide 1-phosphate-stimulated macrophage migration.

    Science.gov (United States)

    Ouro, Alberto; Arana, Lide; Rivera, Io-Guané; Ordoñez, Marta; Gomez-Larrauri, Ana; Presa, Natalia; Simón, Jorge; Trueba, Miguel; Gangoiti, Patricia; Bittman, Robert; Gomez-Muñoz, Antonio

    2014-12-15

    Ceramide 1-phosphate (C1P) was recently demonstrated to potently induce cell migration. This action could only be observed when C1P was applied exogenously to cells in culture, and was inhibited by pertussis toxin. However, the mechanisms involved in this process are poorly understood. In this work, we found that phosphatidic acid (PA), which is structurally related to C1P, displaced radiolabeled C1P from its membrane-binding site and inhibited C1P-stimulated macrophage migration. This effect was independent of the saturated fatty acid chain length or the presence of a double bond in each of the fatty acyl chains of PA. Treatment of RAW264.7 macrophages with exogenous phospholipase D (PLD), an enzyme that produces PA from membrane phospholipids, also inhibited C1P-stimulated cell migration. Likewise, PA or exogenous PLD inhibited C1P-stimulated extracellularly regulated kinases (ERK) 1 and 2 phosphorylation, leading to inhibition of cell migration. However, PA did not inhibit C1P-stimulated Akt phosphorylation. It is concluded that PA is a physiological regulator of C1P-stimulated macrophage migration. These actions of PA may have important implications in the control of pathophysiological functions that are regulated by C1P, including inflammation and various cellular processes associated with cell migration such as organogenesis or tumor metastasis. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. INHIBITION TEST OF METHANOL EXTRACT FROM SOURSOP LEAF (Annona muricata Linn. AGAINST Streptococcus mutans BACTERIA

    Directory of Open Access Journals (Sweden)

    Raudhatul Jannah

    2017-03-01

    Full Text Available Dental caries is a disease with a high prevalence of caries in Indonesia is caused by the bacterium Streptococcus mutans. The leaves of the soursop (Annona muricata Linn. is one of the herbs that can remove dental plaque. This study aims to determine the chemical content and measure the inhibitory antibacterial soursop leaft methanol extractin inhibiting the growth of Streptococcus mutans bacteria. Phytochemical screening stated that the leaf of the soursop contains flavonoids, alkaloids, tannins, steroids, glycosides and saponins. Test of inhibition were measured using paper disc diffusion method with variation concentrations of 5, 10, 15 20, and 25%, positive control is tetrasilkin 30 µg, and a negative control is methanol. Antibacterial test results showed that the methanol extract of soursop leaves have antibacterial activity against Streptococcus mutans at concentrations of 5, 10, 15, 20 and 25% with inhibitory diameter of 9,1; 10,57; 11,53; 12,01 and 13,75 mm respectively.

  3. Deoxynybomycins inhibit mutant DNA gyrase and rescue mice infected with fluoroquinolone-resistant bacteria.

    Science.gov (United States)

    Parkinson, Elizabeth I; Bair, Joseph S; Nakamura, Bradley A; Lee, Hyang Y; Kuttab, Hani I; Southgate, Emma H; Lezmi, Stéphane; Lau, Gee W; Hergenrother, Paul J

    2015-04-24

    Fluoroquinolones are one of the most commonly prescribed classes of antibiotics, but fluoroquinolone resistance (FQR) is widespread and increasing. Deoxynybomycin (DNM) is a natural-product antibiotic with an unusual mechanism of action, inhibiting the mutant DNA gyrase that confers FQR. Unfortunately, isolation of DNM is difficult and DNM is insoluble in aqueous solutions, making it a poor candidate for development. Here we describe a facile chemical route to produce DNM and its derivatives. These compounds possess excellent activity against FQR methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci clinical isolates and inhibit mutant DNA gyrase in-vitro. Bacteria that develop resistance to DNM are re-sensitized to fluoroquinolones, suggesting that resistance that emerges to DNM would be treatable. Using a DNM derivative, the first in-vivo efficacy of the nybomycin class is demonstrated in a mouse infection model. Overall, the data presented suggest the promise of DNM derivatives for the treatment of FQR infections.

  4. Identification and Antimicrobial Activity Detection of Lactic Acid Bacteria Isolated from Corn Stover Silage

    Directory of Open Access Journals (Sweden)

    Dongxia Li

    2015-05-01

    Full Text Available A total of 59 lactic acid bacteria (LAB strains were isolated from corn stover silage. According to phenotypic and chemotaxonomic characteristics, 16S ribosomal DNA (rDNA sequences and recA gene polymerase chain reaction amplification, these LAB isolates were identified as five species: Lactobacillus (L. plantarum subsp. plantarum, Pediococcus pentosaceus, Enterococcus mundtii, Weissella cibaria and Leuconostoc pseudomesenteroides, respectively. Those strains were also screened for antimicrobial activity using a dual-culture agar plate assay. Based on excluding the effects of organic acids and hydrogen peroxide, two L. plantarum subsp. plantarum strains ZZU 203 and 204, which strongly inhibited Salmonella enterica ATCC 43971T, Micrococcus luteus ATCC 4698T and Escherichia coli ATCC 11775T were selected for further research on sensitivity of the antimicrobial substance to heat, pH and protease. Cell-free culture supernatants of the two strains exhibited strong heat stability (60 min at 100°C, but the antimicrobial activity was eliminated after treatment at 121°C for 15 min. The antimicrobial substance remained active under acidic condition (pH 2.0 to 6.0, but became inactive under neutral and alkaline condition (pH 7.0 to 9.0. In addition, the antimicrobial activities of these two strains decreased remarkably after digestion by protease K. These results preliminarily suggest that the desirable antimicrobial activity of strains ZZU 203 and 204 is the result of the production of a bacteriocin-like substance, and these two strains with antimicrobial activity could be used as silage additives to inhibit proliferation of unwanted microorganism during ensiling and preserve nutrients of silage. The nature of the antimicrobial substances is being investigated in our laboratory.

  5. Effect of Bawang Dayak (Eleutherine palmifolia (L) Merr) crude extract towards bacteria inhibition zone and carp (Cyprinus carpio) hematology

    Science.gov (United States)

    Maftuch

    2017-05-01

    Negative impacts of antibiotics and chemical substance usage in aquaculture demand the researchers discover more efficient alternative yet environmentally friendly to overcome fish diseases. One alternative is by using Bawang Dayak (Eleutherine palmifolia (L.) Merr). This research aimed to reveal the effect of Bawang Dayak crude extract towards the inhibition zone of A. hydrophilia, V. harveyi, and P. fluorescens bacteria. Furthermore, it was also conducted to investigate the carp (C. carpio) hematology which was infected with A. hydrophila bacteria, and find the most appropriate dose of Bawang Dayak crude extract to inhibit the bacteria. This experimental research was performed by using Completely Randomized Design with 4 treatments and 3 replications. The best result of the zone of inhibition test in A. hydrophila bacteria was at the dose of 70 ppm while V. harveyi and P. Fluorescens bacteria were at the dose of 85 ppm. Then, fish hematology was found best at the dose of 80 ppm. Bawang Dayak crude extract was significant towards the inhibition zone of A. hydrophila, V. harveyi and P. Fluorescens bacteria, and carp hematology which was infected with A. hydrophila bacteria.

  6. Genome-Scale Model of Streptococcus thermophilus LMG18311 for Metabolic Comparison of Lactic Acid Bacteria

    NARCIS (Netherlands)

    Pastink, M.I.; Teusink, B.; Hols, P.; Visser, S.; Vos, de W.M.; Hugenholtz, J.

    2009-01-01

    In this report we describe amino acid-metabolism and amino acid-dependency of the dairy bacterium Streptococcus thermophilus LMG18311 and compare that with two other characterized lactic acid bacteria, Lactococcus lactis and Lactobacillus plantarum. Through the construction of a genome-scale

  7. Beneficial Protective Role of Endogenous Lactic Acid Bacteria Against Mycotic Contamination of Honeybee Beebread.

    Science.gov (United States)

    Janashia, Irakli; Choiset, Yvan; Jozefiak, Damian; Déniel, Franck; Coton, Emmanuel; Moosavi-Movahedi, Ali Akbar; Chanishvili, Nina; Haertlé, Thomas

    2018-01-03

    The purpose of this article is to reveal the role of the lactic acid bacteria (LAB) in the beebread transformation/preservation, biochemical properties of 25 honeybee endogenous LAB strains, particularly: antifungal, proteolytic, and amylolytic activities putatively expressed in the beebread environment have been studied. Seventeen fungal strains isolated from beebread samples were identified and checked for their ability to grow on simulated beebread substrate (SBS) and then used to study mycotic propagation in the presence of LAB. Fungal strains identified as Aspergillus niger (Po1), Candida sp. (BB01), and Z. rouxii (BB02) were able to grow on SBS. Their growth was partly inhibited when co-cultured with the endogenous honeybee LAB strains studied. No proteolytic or amylolytic activities of the studied LAB were detected using pollen, casein starch based media as substrates. These findings suggest that some honeybee LAB symbionts are involved in maintaining a safe microbiological state in the host honeybee colonies by inhibiting beebread mycotic contaminations, starch, and protein predigestion in beebread by LAB is less probable. Honeybee endogenous LAB use pollen as a growth substrate and in the same time restricts fungal propagation, thus showing host beneficial action preserving larval food. This study also can have an impact on development of novel methods of pollen preservation and its processing as a food ingredient.

  8. Characterization of bacteriocinogenic strains of lactic acid bacteria from traditional Slovenian cheese ‘Tolminc’

    Directory of Open Access Journals (Sweden)

    Aljoša Trmčić

    2010-12-01

    Full Text Available The purpose of this research was to examine traditional Slovenian ‘Tolminc’ cheese for the presence of lactic acid bacteria that produce several bacteriocins. The presence of gene determinants for different bacteriocins in this type of cheese and in the cultivable population of ‘Tolminc’ microbiota, have already been demonstrated, as well as its antimicrobial activity. Due to the difficulties in connecting the presence of gene determinants for bacteriocins with the observed antimicrobial activity it was decided to examine in this study the same features on the level of individual bacteriocinogenic strains. Like in previous results, enterococci and their bacteriocins prevailed in cheese microbial consortia. None of isolated strains inhibited growth of Staphylococcus aureus, while the other indicator strains were inhibited in a strain specific manner. Most of isolated strains carried gene determinants for cytolysin. On the basis of gene determinants for bacteriocins, antimicrobial activity, phenotyping by PhP (PhenePlateTM system and PCR identification, some similarities found were among Enterococcus isolates.

  9. Lactic acid bacteria affect serum cholesterol levels, harmful fecal enzyme activity, and fecal water content

    Directory of Open Access Journals (Sweden)

    Chung Myung

    2009-06-01

    Full Text Available Abstract Background Lactic acid bacteria (LAB are beneficial probiotic organisms that contribute to improved nutrition, microbial balance, and immuno-enhancement of the intestinal tract, as well as lower cholesterol. Although present in many foods, most trials have been in spreads or dairy products. Here we tested whether Bifidobacteria isolates could lower cholesterol, inhibit harmful enzyme activities, and control fecal water content. Methods In vitro culture experiments were performed to evaluate the ability of Bifidobacterium spp. isolated from healthy Koreans (20~30 years old to reduce cholesterol-levels in MRS broth containing polyoxyethanylcholesterol sebacate. Animal experiments were performed to investigate the effects on lowering cholesterol, inhibiting harmful enzyme activities, and controlling fecal water content. For animal studies, 0.2 ml of the selected strain cultures (108~109 CFU/ml were orally administered to SD rats (fed a high-cholesterol diet every day for 2 weeks. Results B. longum SPM1207 reduced serum total cholesterol and LDL levels significantly (p B. longum SPM1207 also increased fecal LAB levels and fecal water content, and reduced body weight and harmful intestinal enzyme activities. Conclusion Daily consumption of B. longum SPM1207 can help in managing mild to moderate hypercholesterolemia, with potential to improve human health by helping to prevent colon cancer and constipation.

  10. Influence of Co-Doping of Ni (II on Photocatalytic Activity of TiO2 for Pathogenic Bacteria Inhibition

    Directory of Open Access Journals (Sweden)

    Baharuddin Shaleh

    2010-04-01

    Full Text Available Nanoparticle titanium dioxide (TiO2 has most attention in the past decade, since it can be applied as alternative material on sterilization photocatalyst process. This research focused on increasing performance of titania such as structure, particles size and surface area through Ni ion doped on TiO2 surface by sol-gel technique. Product were used to design of a photobioreactor for sterilization process from pathogenic bacteria such as Escherichia coli, Staphylococcus aureus and Bacillus subtilis. Product were characterized using TG-DTA, XRD, TEM, SEM-EDS and BET. Titanium dioxide with anatase structure have 12.1 nm in particles size and surface area 49.6 m2/ g that have higher inhibition rate to bacteria cell. Photobiocatalytic reaction was carried out in various TiO2-Ni concentration and UV irradiation times. The anti bacteria from TiO2-Ni to all bacteria cell suspension after UV irradiated at λm : 365 nm has good synergistic effect. Effect of mechanical treatment by sonicator showed the increasing inhibition rate around 4% for 120 minute irradiation. Inhibition rate optimization for each bacteria gave different efficiency inhibition to TiO2-Ni concentration 1.5-2.0 g/L. TiO2-Ni inhibited growth of Escherichia coli, Staphylococcus aureus around ≥ 95% for 120 minute irradiation, while Bacillus subtilis resistance with inhibition percentage rate only 88.1%.

  11. Streptomyces lunalinharesii Strain 235 Shows the Potential to Inhibit Bacteria Involved in Biocorrosion Processes

    Directory of Open Access Journals (Sweden)

    Juliana Pacheco da Rosa

    2013-01-01

    Full Text Available Four actinomycete strains previously isolated from Brazilian soils were tested for their antimicrobial activity against Bacillus pumilus LF-4 and Desulfovibrio alaskensis NCIMB 13491, bacteria that are well known to be involved in biofilm formation and biocorrosion. Strain 235, belonging to the species Streptomyces lunalinharesii, inhibited the growth of both bacteria. The antimicrobial activity was seen over a wide range of pH, and after treatment with several chemicals and heat but not with proteinase K and trypsin. The antimicrobial substances present in the concentrated supernatant from growth media were partially characterized by SDS-PAGE and extracellular polypeptides were seen. Bands in the size range of 12 to 14.4 kDa caused antimicrobial activity. Transmission electron microscopy of D. alaskensis cells treated with the concentrated supernatant containing the antimicrobial substances revealed the formation of prominent bubbles, the spherical double-layered structures on the cell membrane, and the periplasmic space completely filled with electron-dense material. This is the first report on the production of antimicrobial substances by actinomycetes against bacteria involved in biocorrosion processes, and these findings may be of great relevance as an alternative source of biocides to those currently employed in the petroleum industry.

  12. Comparative analysis of proteins with a mucus-binding domain found exclusively in lactic acid bacteria

    NARCIS (Netherlands)

    Boekhorst, J.; Helmer, Q.; Kleerebezem, M; Siezen, R.J.

    2006-01-01

    Lactic acid bacteria (LAB) are frequently encountered inhabitants of the human intestinal tract. A protective layer of mucus covers the epithelial cells of the intestine, offering an attachment site for these bacteria. In this study bioinformatics tools were used to identify and characterize

  13. Identification of TLR2/TLR6 signalling lactic acid bacteria for supporting immune regulation

    NARCIS (Netherlands)

    Ren, Shengcheng; Zhang, Qiuxiang; de Haan, Bart J.; Zhang, Hao; Faas, Marijke M.; de Vos, Paul

    2016-01-01

    Although many lactic acid bacteria (LAB) influence the consumer's immune status it is not completely understood how this is established. Bacteria-host interactions between bacterial cell-wall components and toll-like receptors (TLRs) have been suggested to play an essential role. Here we

  14. Effect of lactic acid bacteria on the textural properties of an edible ...

    African Journals Online (AJOL)

    This study was aimed to evaluate the effects of different components and the addition of probiotic bacteria of lactic acid bacteria (LAB, Lactobacillus casei) on the physicochemical and textural characteristics of edible films using a response surface Box-Behnken design. The edible films were made of the following ...

  15. Effect of lactic acid bacteria on the textural properties of an edible ...

    African Journals Online (AJOL)

    Rodrigo

    2013-05-08

    May 8, 2013 ... This study was aimed to evaluate the effects of different components and the addition of probiotic bacteria of lactic acid bacteria (LAB, Lactobacillus casei) on the physicochemical and textural characteristics of edible films using a response surface Box-Behnken design. The edible films were made of the ...

  16. From physiology to systems metabolic engineering for the production of biochemicals by lactic acid bacteria

    DEFF Research Database (Denmark)

    Gaspar, Paula; Carvalho, Ana L.; Vinga, Susana

    2013-01-01

    The lactic acid bacteria (LAB) are a functionally related group of low-GC Gram-positive bacteria known essentially for their roles in bioprocessing of foods and animal feeds. Due to extensive industrial use and enormous economical value, LAB have been intensively studied and a large body of compr...

  17. Theobromine inhibits uric acid crystallization. A potential application in the treatment of uric acid nephrolithiasis.

    Science.gov (United States)

    Grases, Felix; Rodriguez, Adrian; Costa-Bauza, Antonia

    2014-01-01

    To assess the capacity of methylxanthines (caffeine, theophylline, theobromine and paraxanthine) to inhibit uric acid crystallization, and to evaluate their potential application in the treatment of uric acid nephrolithiasis. The ability of methylxathines to inhibit uric acid nucleation was assayed turbidimetrically. Crystal morphology and its modification due to the effect of theobromine were evaluated by scanning electron microscopy (SEM). The ability of theobromine to inhibit uric acid crystal growth on calculi fragments resulting from extracorporeal shock wave lithotripsy (ESWL) was evaluated using a flow system. The turbidimetric assay showed that among the studied methylxanthines, theobromine could markedly inhibit uric acid nucleation. SEM images showed that the presence of theobromine resulted in thinner uric acid crystals. Furthermore, in a flow system theobromine blocked the regrowth of post-ESWL uric acid calculi fragments. Theobromine, a natural dimethylxanthine present in high amounts in cocoa, acts as an inhibitor of nucleation and crystal growth of uric acid. Therefore, theobromine may be clinically useful in the treatment of uric acid nephrolithiasis.

  18. Theobromine inhibits uric acid crystallization. A potential application in the treatment of uric acid nephrolithiasis.

    Directory of Open Access Journals (Sweden)

    Felix Grases

    Full Text Available To assess the capacity of methylxanthines (caffeine, theophylline, theobromine and paraxanthine to inhibit uric acid crystallization, and to evaluate their potential application in the treatment of uric acid nephrolithiasis.The ability of methylxathines to inhibit uric acid nucleation was assayed turbidimetrically. Crystal morphology and its modification due to the effect of theobromine were evaluated by scanning electron microscopy (SEM. The ability of theobromine to inhibit uric acid crystal growth on calculi fragments resulting from extracorporeal shock wave lithotripsy (ESWL was evaluated using a flow system.The turbidimetric assay showed that among the studied methylxanthines, theobromine could markedly inhibit uric acid nucleation. SEM images showed that the presence of theobromine resulted in thinner uric acid crystals. Furthermore, in a flow system theobromine blocked the regrowth of post-ESWL uric acid calculi fragments.Theobromine, a natural dimethylxanthine present in high amounts in cocoa, acts as an inhibitor of nucleation and crystal growth of uric acid. Therefore, theobromine may be clinically useful in the treatment of uric acid nephrolithiasis.

  19. Theobromine Inhibits Uric Acid Crystallization. A Potential Application in the Treatment of Uric Acid Nephrolithiasis

    Science.gov (United States)

    Grases, Felix; Rodriguez, Adrian; Costa-Bauza, Antonia

    2014-01-01

    Purpose To assess the capacity of methylxanthines (caffeine, theophylline, theobromine and paraxanthine) to inhibit uric acid crystallization, and to evaluate their potential application in the treatment of uric acid nephrolithiasis. Materials and Methods The ability of methylxathines to inhibit uric acid nucleation was assayed turbidimetrically. Crystal morphology and its modification due to the effect of theobromine were evaluated by scanning electron microscopy (SEM). The ability of theobromine to inhibit uric acid crystal growth on calculi fragments resulting from extracorporeal shock wave lithotripsy (ESWL) was evaluated using a flow system. Results The turbidimetric assay showed that among the studied methylxanthines, theobromine could markedly inhibit uric acid nucleation. SEM images showed that the presence of theobromine resulted in thinner uric acid crystals. Furthermore, in a flow system theobromine blocked the regrowth of post-ESWL uric acid calculi fragments. Conclusions Theobromine, a natural dimethylxanthine present in high amounts in cocoa, acts as an inhibitor of nucleation and crystal growth of uric acid. Therefore, theobromine may be clinically useful in the treatment of uric acid nephrolithiasis. PMID:25333633

  20. Lactic Acid Bacteria from Kefir Increase Cytotoxicity of Natural Killer Cells to Tumor Cells.

    Science.gov (United States)

    Yamane, Takuya; Sakamoto, Tatsuji; Nakagaki, Takenori; Nakano, Yoshihisa

    2018-03-27

    The Japanese fermented beverage, homemade kefir, contains six lactic acid bacteria: Lactococcus. lactis subsp. Lactis , Lactococcus . lactis subsp. Cremoris , Lactococcus. Lactis subsp. Lactis biovar diacetylactis , Lactobacillus plantarum , Leuconostoc meseuteroides subsp. Cremoris and Lactobacillus casei . In this study, we found that a mixture of the six lactic acid bacteria from kefir increased the cytotoxicity of human natural killer KHYG-1 cells to human chronic myelogenous leukemia K562 cells and colorectal tumor HCT116 cells. Furthermore, levels of mRNA expression and secretion of IFN-γ (interferon gamma) increased in KHYG-1 cells that had been treated with the six lactic acid bacteria mixture from kefir. The results suggest that the six lactic acid bacteria mixture from kefir has strong effects on natural immunity and tumor cell cytotoxicity.

  1. Lactic acid bacteria of the Leuconostoc genus with high innate immunity-stimulating activity.

    Science.gov (United States)

    Ishii, Masaki; Nishida, Satoshi; Kataoka, Keiko; Nishiyama, Yayoi; Abe, Shigeru; Sekimizu, Kazuhisa

    2017-03-22

    We screened lactic acid bacteria that exhibited high innate immunity-stimulating activity by monitoring muscle contraction activity in silkworms. Heat-treated fractions of lactic acid bacteria, Leuconostoc carnosum #7-2, Leuconostoc gelidum #4-2, and Leuconostoc mesenteroides 8/11-3, had high (250-460 units/mg) innate immunity-stimulating activity. These lactic acid bacteria proliferated in milk to concentrations of 1 × 10 6 colony forming unit/mL. The present findings suggest that the silkworm muscle contraction assay is useful for screening lactic acid bacteria with high innate immunity-stimulating activity, and that the assay can be used for the production of fermented foods made from milk.

  2. Bacillus spp. produce antibacterial activities against lactic acid bacteria that contaminate fuel ethanol plants

    Science.gov (United States)

    Lactic acid bacteria (LAB) frequently contaminate commercial fuel ethanol fermentations, reducing yields and decreasing profitability of biofuel production. Microorganisms from environmental sources in different geographic regions of Thailand were tested for antibacterial activity against LAB. Fou...

  3. Antibacterial Activity of Some Lactic Acid Bacteria Isolated from an Algerian Dairy Product

    International Nuclear Information System (INIS)

    Mezaini, A.; Bouras, A.D.; Mezaini, A.; Chihib, N.; Nedjar-Arroume, N.; Hornez, J.P.

    2010-01-01

    In the present study, the antibacterial effect of 20 lactic acid bacteria isolates from a traditional cheese was investigated. 6 isolates showed antibacterial effect against Gram positive bacteria. Streptococcus thermophilus T2 strain showed the wide inhibitory spectrum against the Gram positive bacteria. Growth and bacitracin production profiles showed that the maximal bacitracin production, by S. thermophilus T2 cells, was measured by the end of the late-log phase (90 AU ml -1 ) with a bacterio cine production rate of 9.3 (AU ml -1 ) h -1 . In addition, our findings showed that the bacitracin, produced by S. thermophilus T2, was stable over a wide ph range (4-8); this indicates that such bacitracin may be useful in acidic as well as non acidic food. This preliminarily work shows the potential application of autochthonous lactic acid bacteria to improve safety of traditional fermented food.

  4. Influence of starter culture of lactic acid bacteria on the shelf life of ...

    African Journals Online (AJOL)

    A total of eight lactic acid bacteria were isolated from various fermented cereal gruels (ogi). They were identified as Lactobacillus plantarum, Lactobacillus casei, Leuconostoc mesenteroides, Lactobacillus brevis, Lactobacillus fermentum, Lactobacillus delbrueckii, Lactobacillus acidophilus and Pediococcus acidilactici.

  5. Structure-function relationships of glucansucrase and fructansucrase enzymes from lactic acid bacteria

    NARCIS (Netherlands)

    Hijum, S.A.F.T. van; Kralj, S.; Ozimek, L.K.; Dijkhuizen, L.; Geel-Schutten, G.H. van

    2006-01-01

    Lactic acid bacteria (LAB) employ sucrase-type enzymes to convert sucrose into homopolysaccharides consisting of either glucosyl units (glucans) or fructosyl units (fructans). The enzymes involved are labeled glucansucrases (GS) and fructansucrases (FS), respectively. The available molecular,

  6. Mutually stimulating interactions between lactic acid bacteria and Saccharomyces cerevisiae in sourdough fermentation

    NARCIS (Netherlands)

    Sieuwerts, Sander; Bron, Peter A.; Smid, Eddy J.

    2018-01-01

    Interactions between microorganisms are key to their performance in food habitats. Improved understanding of these interactions supports rational improvement of food fermentations. This study aimed at identifying interactions between lactic acid bacteria and yeast during sourdough fermentation.

  7. Molecular Characterization of Intrinsic and Acquired antibiotic resistance in lactic Acid bacteria and Bifidobacteria

    NARCIS (Netherlands)

    Ammor, M.S.; Flórez, A.B.; Hoek, van A.H.A.M.; Reyes-Gavilan, de los C.G.; Aarts, H.J.M.; Margolles, A.; Mayo, B.

    2008-01-01

    The minimum inhibitory concentrations (MICs) of 6 different antibiotics (chloramphenicol, clindamycin, erythromycin, streptomycin, tetracycline and vancomycin) were determined for 143 strains of lactic acid bacteria and bifidobacteria using the Etest. Different MICs were found for different species

  8. Lipoteichoic acid preparations of gram-positive bacteria induce interleukin-12 through a CD14-dependent pathway.

    Science.gov (United States)

    Cleveland, M G; Gorham, J D; Murphy, T L; Tuomanen, E; Murphy, K M

    1996-01-01

    Interleukin 12 (IL-12) strongly augments gamma interferon production by natural killer (NK) and T cells. IL-12 also promotes effective cell-mediated immune responses, which are particularly important against intracellular bacteria such as Listeria monocytogenes. While the lipopolysaccharide (LPS) of gram-negative bacteria induces monocyte production of IL-12, the relevant gram-positive components which induce IL-12 production are uncharacterized. We used the human monocytic cell line THP-1 to study IL-12 induction by gram-positive bacteria. Muramyl dipeptides as well as the major muramyl tetrapeptide component of Streptococcus pneumoniae were inactive for inducing IL-12. In contrast, lipoteichoic acid (LTA), a predominant surface glycolipid of gram-positive bacteria, potently induced IL-12 p40 gene expression. A competitive LPS antagonist, Rhodobacter sphaeroides LPS, inhibited LTA-induced IL-12 production, suggesting a common pathway for LPS and LTA in IL-12 activation. Pretreatment of cells with anti-CD14 monoclonal antibody blocked both LPS and LTA induction of IL-12 p40 expression. LTA also induced Thl development in naive CD4 T cells by an IL-12-dependent mechanism, indicating direct induction of physiologic levels of IL-12. Together, these results show that LTA is a potent surface structure of gram-positive bacteria which induces IL-12 in monocytes through a CD14-mediated pathway. PMID:8675286

  9. Chlorogenic Acid Inhibits Human Platelet Activation and Thrombus Formation

    Science.gov (United States)

    Fuentes, Eduardo; Caballero, Julio; Alarcón, Marcelo; Rojas, Armando; Palomo, Iván

    2014-01-01

    Background Chlorogenic acid is a potent phenolic antioxidant. However, its effect on platelet aggregation, a critical factor in arterial thrombosis, remains unclear. Consequently, chlorogenic acid-action mechanisms in preventing platelet activation and thrombus formation were examined. Methods and Results Chlorogenic acid in a dose-dependent manner (0.1 to 1 mmol/L) inhibited platelet secretion and aggregation induced by ADP, collagen, arachidonic acid and TRAP-6, and diminished platelet firm adhesion/aggregation and platelet-leukocyte interactions under flow conditions. At these concentrations chlorogenic acid significantly decreased platelet inflammatory mediators (sP-selectin, sCD40L, CCL5 and IL-1β) and increased intraplatelet cAMP levels/PKA activation. Interestingly, SQ22536 (an adenylate cyclase inhibitor) and ZM241385 (a potent A2A receptor antagonist) attenuated the antiplatelet effect of chlorogenic acid. Chlorogenic acid is compatible to the active site of the adenosine A2A receptor as revealed through molecular modeling. In addition, chlorogenic acid had a significantly lower effect on mouse bleeding time when compared to the same dose of aspirin. Conclusions Antiplatelet and antithrombotic effects of chlorogenic acid are associated with the A2A receptor/adenylate cyclase/cAMP/PKA signaling pathway. PMID:24598787

  10. ISOLATION AND IDENTIFICATION OF LACTIC ACID PRODUCING BACTERIA FROM CAMEL MILK

    OpenAIRE

    Toqeer Ahmad, Rashida Kanwal, Izhar Hussain Athar1, Najam Ayub

    2002-01-01

    Lactic acid bacteria (LAB) were isolated from camel milk by culturing the camel milk on specific media and pure culture was obtained by sub culturing. Purification of culture was confirmed by Gram's staining and identified by different bio-chemical tests. Camel milk contains lactic acid producing bacteria including Strpptococci such as S. cremoris and S. lactis and Lactobacilli such as L. acidophilus L. acidophilus grows more rapidly in camel milk than others as its growth is supported by cam...

  11. Characterization of lactic acid bacteria isolated from poultry farms in Senegal

    OpenAIRE

    Coulibaly, Ibourahema; Dubois Dauphin, Robin; Destain, Jacqueline; Thonart, Philippe

    2008-01-01

    The group that includes the lactic acid bacteria is one of the most diverse groups of bacteria known and these organisms have been characterized extensively by using different techniques. In this study, thirty lactic acid bacterial strains were isolated from soils chicken faeces and feathers. A total of nineteen isolates were obtained and by sequential screening for catalase activity and Gram-staining, eight were determined to be LAB out of which six were established to be homofermentative by...

  12. Inhibition of fatty acid metabolism reduces human myeloma cells proliferation.

    Directory of Open Access Journals (Sweden)

    José Manuel Tirado-Vélez

    Full Text Available Multiple myeloma is a haematological malignancy characterized by the clonal proliferation of plasma cells. It has been proposed that targeting cancer cell metabolism would provide a new selective anticancer therapeutic strategy. In this work, we tested the hypothesis that inhibition of β-oxidation and de novo fatty acid synthesis would reduce cell proliferation in human myeloma cells. We evaluated the effect of etomoxir and orlistat on fatty acid metabolism, glucose metabolism, cell cycle distribution, proliferation, cell death and expression of G1/S phase regulatory proteins in myeloma cells. Etomoxir and orlistat inhibited β-oxidation and de novo fatty acid synthesis respectively in myeloma cells, without altering significantly glucose metabolism. These effects were associated with reduced cell viability and cell cycle arrest in G0/G1. Specifically, etomoxir and orlistat reduced by 40-70% myeloma cells proliferation. The combination of etomoxir and orlistat resulted in an additive inhibitory effect on cell proliferation. Orlistat induced apoptosis and sensitized RPMI-8226 cells to apoptosis induction by bortezomib, whereas apoptosis was not altered by etomoxir. Finally, the inhibitory effect of both drugs on cell proliferation was associated with reduced p21 protein levels and phosphorylation levels of retinoblastoma protein. In conclusion, inhibition of fatty acid metabolism represents a potential therapeutic approach to treat human multiple myeloma.

  13. Assessment of probiotic properties in lactic acid bacteria isolated from wine.

    Science.gov (United States)

    García-Ruiz, Almudena; González de Llano, Dolores; Esteban-Fernández, Adelaida; Requena, Teresa; Bartolomé, Begoña; Moreno-Arribas, M Victoria

    2014-12-01

    Probiotic properties are highly strain-dependent but rarely studied in enological lactic acid bacteria (LAB). In this study, the probiotic features of 11 strains of Lactobacillus spp., Pediococcus spp., and Oenococcus oeni, including saliva and acid resistance, bile tolerance and exopolysaccharides' production, were investigated. The assays included two probiotic reference strains (Lactobacillus plantarum CLC 17 and Lactobacillus fermentum CECT5716). The Lactobacillus and Pediococcus strains showed high resistance to lysozyme (>80% resistance to 100 mg/L of lysozyme under conditions simulating the in vivo dilution by saliva) and were capable of surviving at low pH values (pH 1.8) and bile salts, suggesting good adaptation of the wine strains to gastrointestinal conditions. The ability of the strains to adhere to the intestinal mucosa and the inhibition of the adhesion of Escherichia coli to human intestinal cells were also evaluated. Adhesion levels of enological LAB to Caco-2 cells varied from 0.37% to 12.2%, depending on the strain. In particular, Pediococcus pentosaceus CIAL-86 showed a high percentage of adhesion to intestinal cells (>12%), even higher than that shown by the probiotic reference strains, and a high anti-adhesion activity against E. coli CIAL-153 (>30%), all of which support this wine LAB strain as a potential probiotic. Published by Elsevier Ltd.

  14. Oxalate-Degrading Enzyme Recombined Lactic Acid Bacteria Strains Reduce Hyperoxaluria.

    Science.gov (United States)

    Zhao, Chenming; Yang, Huan; Zhu, Xiaojing; Li, Yang; Wang, Ning; Han, Shanfu; Xu, Hua; Chen, Zhiqiang; Ye, Zhangqun

    2017-12-02

    To develop recombinant lactic acid bacteria (LAB) strains that express oxalate-degrading enzymes through biotechnology-based approach for the treatment of hyperoxaluria by oral administration. The coding gene of oxalate decarboxylase (ODC) and oxalate oxidase (OxO) was transformed into Lactococcus lactis MG1363. The oxalate degradation ability in vitro was evaluated in media with high concentration of oxalate. Hyperoxaluria rat models through high oxalate diet were given recombinant LAB through oral administration. Twenty-four-hour urinary oxalate was measured, and kidney stone formation was investigated. LAB recombined with the coding gene of ODC could effectively decrease the amount of oxalate in the media and in the urine of rats. Moreover, the formation of calcium oxalate crystals in kidneys was also inhibited. The acid-induced promoter p170 significantly enhanced the reduction of hyperoxaluria. However, recombinant LAB expressing heterologous OxO showed less efficiency in oxalate degradation even in the presence of p170. LAB expressing ODC is more efficient in degradation of oxalate in vitro and in vivo than that expressing OxO. This present study provided novel recombinant probiotic strains as a potential treatment tool against oxalosis. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Characterization of the spoilage lactic acid bacteria in "sliced vacuum-packed cooked ham".

    Science.gov (United States)

    Kalschne, Daneysa Lahis; Womer, Rute; Mattana, Ademir; Sarmento, Cleonice Mendes Pereira; Colla, Luciane Maria; Colla, Eliane

    2015-03-01

    The lactic acid bacteria are involved with food fermentation and in such cases with food spoilage. Considering the need to reduce the lactic acid bacteria growth in meat products, the aim of this work was to enumerated and investigated the lactic acid bacteria present on sliced vacuum-packed cooked ham stored at 4 °C and 8 °C for 45 days by phenotypic and molecular techniques. The quantification showed that the lactic acid bacteria were present from the first day with mean count of 1.98 log cfu/g for the four batches analyzed. The lactic acid bacteria grew rapidly on the samples, and plate counts around 7.59 log cfu/g and 8.25 log cfu/g were detected after 45 days of storage at 4 °C and 8 °C, respectively; storage temperatures studied showed significant influence on the microorganism in study growth. The predominant lactic acid bacteria associated with the spoilage samples at one day of storage includes Lactobacillus sp., the phenotypic overlap Leuconostoc / Weissella sp. and Enterococcus sp. At 45 days of storage at 4 and 8 °C the mainly specie was Lactobacillus curvatus , following by Lactobacillus sakei and Leuconostoc mesentereoides ; the Enterococcus sp. was not present in the samples.

  16. Characterization of the spoilage lactic acid bacteria in “sliced vacuum-packed cooked ham”

    Science.gov (United States)

    Kalschne, Daneysa Lahis; Womer, Rute; Mattana, Ademir; Sarmento, Cleonice Mendes Pereira; Colla, Luciane Maria; Colla, Eliane

    2015-01-01

    The lactic acid bacteria are involved with food fermentation and in such cases with food spoilage. Considering the need to reduce the lactic acid bacteria growth in meat products, the aim of this work was to enumerated and investigated the lactic acid bacteria present on sliced vacuum-packed cooked ham stored at 4 °C and 8 °C for 45 days by phenotypic and molecular techniques. The quantification showed that the lactic acid bacteria were present from the first day with mean count of 1.98 log cfu/g for the four batches analyzed. The lactic acid bacteria grew rapidly on the samples, and plate counts around 7.59 log cfu/g and 8.25 log cfu/g were detected after 45 days of storage at 4 °C and 8 °C, respectively; storage temperatures studied showed significant influence on the microorganism in study growth. The predominant lactic acid bacteria associated with the spoilage samples at one day of storage includes Lactobacillus sp., the phenotypic overlap Leuconostoc / Weissella sp. and Enterococcus sp. At 45 days of storage at 4 and 8 °C the mainly specie was Lactobacillus curvatus , following by Lactobacillus sakei and Leuconostoc mesentereoides ; the Enterococcus sp. was not present in the samples. PMID:26221105

  17. Characterization of the spoilage lactic acid bacteria in “sliced vacuum-packed cooked ham”

    Directory of Open Access Journals (Sweden)

    Daneysa Lahis Kalschne

    2015-03-01

    Full Text Available The lactic acid bacteria are involved with food fermentation and in such cases with food spoilage. Considering the need to reduce the lactic acid bacteria growth in meat products, the aim of this work was to enumerated and investigated the lactic acid bacteria present on sliced vacuum-packed cooked ham stored at 4 °C and 8 °C for 45 days by phenotypic and molecular techniques. The quantification showed that the lactic acid bacteria were present from the first day with mean count of 1.98 log cfu/g for the four batches analyzed. The lactic acid bacteria grew rapidly on the samples, and plate counts around 7.59 log cfu/g and 8.25 log cfu/g were detected after 45 days of storage at 4 °C and 8 °C, respectively; storage temperatures studied showed significant influence on the microorganism in study growth. The predominant lactic acid bacteria associated with the spoilage samples at one day of storage includes Lactobacillus sp., the phenotypic overlap Leuconostoc/Weissella sp. and Enterococcus sp. At 45 days of storage at 4 and 8 °C the mainly specie was Lactobacillus curvatus, following by Lactobacillus sakei and Leuconostoc mesentereoides; the Enterococcus sp. was not present in the samples.

  18. Characteristics of Lactic Acid Bacteria Isolated from Gastrointestinal Tract of Cemani Chicken and Their Potential Use as Probiotics

    Directory of Open Access Journals (Sweden)

    S. N. Jannah

    2014-12-01

    Full Text Available The aims of this study were to screen and characterize lactic acid bacteria (LAB isolated from gastrointestinal (GI tract of Cemani chicken, one of Indonesian local chicken and to investigate their potential use as probiotics. LAB were isolated from GI tract using MRSA and GYPA media and incubated anaerobically. Selected LAB were determined their probiotic properties with several assays. Identification of selected LAB was based on 16S rDNA sequences, morphological and biochemical characteristics. Ninety five bacteria were isolated and characterized as lactic acid bacteria (Gram positive, catalase negative, non sporeforming and acid producing. Twenty four isolates of LAB demonstrated antimicrobial activity against Escherichia coli JCM 1649 and Salmonella enteritidis B2586, and three selected isolates, i.e. CCM011, CSP004, and CVM002 showed the highest inhibition activity. The isolates had characters of high cell surface hydrophobicity and inter-isolate coaggregation ability of LAB, high survival at low pH, high phytase and protease activity (but no amylase and lipase activity, weak coaggregation with pathogen and no resistance to the examined antibiotics. The isolates were identified based on sequence analysis of 16S rRNA gene as Lactobacillus salivarius, however, each isolate had different profiles of sugar fermentation. Therefore the three LAB isolates had potential application as probiotics for chicken.

  19. Assessment of the in vitro bioactive properties of lactic acid bacteria isolated from native ecological niches of Ecuador.

    Science.gov (United States)

    Benavides, Ana B; Ulcuango, Mario; Yépez, Lucía; Tenea, Gabriela N

    Lactic acid bacteria are known for their biotechnological potential. In various regions of Ecuador numerous indigenous biological resources are largely undocumented. In this study, we evaluated the potential probiotic characteristics and antagonistic in vitro properties of some lactic acid bacteria from native niches of the subtropical rain forests of Ecuador. These isolates were identified according to their morphological properties, standard API50CH fermentation profile and RAPD-DNA polymorphism pattern. The selected isolates were further evaluated for their probiotic potential. The isolates grew at 15°C and 45°C, survived at a pH ranging from 2.5 to 4.5 in the presence of 0.3% bile (>90%) and grew under sodium chloride conditions. All selected isolates were sensitive to ampicillin, amoxicillin and cefuroxime and some showed resistance to gentamicin, kanamycin and tetracycline. Moreover, the agar well diffusion assay showed that the supernatant of each strain at pH 3.0 and pH 4.0, but not at pH 7.0 exhibited increased antimicrobial activity (inhibition zone >15mm) against two foodborne pathogens, Escherichia coli and Salmonella spp. To our knowledge, this is the first report describing the antagonistic activity against two foodborne pathogens and the probiotic in vitro potential of lactic acid bacteria isolated from native biota of Ecuador. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Using In Vitro Immunomodulatory Properties of Lactic Acid Bacteria for Selection of Probiotics against Salmonella Infection in Broiler Chicks.

    Directory of Open Access Journals (Sweden)

    Junchang Feng

    Full Text Available Poultry is known to be a major reservoir of Salmonella. The use of lactic acid bacteria has become one of successful strategies to control Salmonella in poultry. The purpose of this study was to select lactic acid bacteria strains by their in vitro immunomodulatory properties for potential use as probiotics against Salmonella infection in broiler chicks. Among 101 isolated lactic acid bacteria strains, 13 strains effectively survived under acidic (pH 2.5 and bile salt (ranging from 0.1% to 1.0% conditions, effectively inhibited growth of 6 pathogens, and adhered to Caco-2 cells. However, their in vitro immunomodulatory activities differed significantly. Finally, three strains with higher in vitro immunomodulatory properties (Lactobacillus plantarum PZ01, Lactobacillus salivarius JM32 and Pediococcus acidilactici JH231 and three strains with lower in vitro immunomodulatory activities (Enterococcus faecium JS11, Lactobacillus salivarius JK22 and Lactobacillus salivarius JM2A1 were compared for their inhibitory effects on Salmonella adhesion and invasion to Caco-2 cells in vitro and their antimicrobial effects in vivo. The former three strains inhibited Salmonella adhesion and invasion to Caco-2 cells in vitro, reduced the number of Salmonella in intestinal content, spleen and liver, reduced the levels of lipopolysaccharide-induced TNF-α factor (LITAF, IL-1β, IL-6 and IL-12 in serum and increased the level of IL-10 in serum during a challenge study in vivo more efficiently than the latter three strains. These results suggest that in vitro immunomodulatory activities could be used as additional parameters to select more effective probiotics as feed supplements for poultry.

  1. Muricholic acids inhibit Clostridium difficile spore germination and growth.

    Directory of Open Access Journals (Sweden)

    Michael B Francis

    Full Text Available Infections caused by Clostridium difficile have increased steadily over the past several years. While studies on C. difficile virulence and physiology have been hindered, in the past, by lack of genetic approaches and suitable animal models, newly developed technologies and animal models allow these processes to be studied in detail. One such advance is the generation of a mouse-model of C. difficile infection. The development of this system is a major step forward in analyzing the genetic requirements for colonization and infection. While important, it is equally as important in understanding what differences exist between mice and humans. One of these differences is the natural bile acid composition. Bile acid-mediated spore germination is an important step in C. difficile colonization. Mice produce several different bile acids that are not found in humans. These muricholic acids have the potential to impact C. difficile spore germination. Here we find that the three muricholic acids (α-muricholic acid, β-muricholic acid and ω-muricholic acid inhibit C. difficile spore germination and can impact the growth of vegetative cells. These results highlight an important difference between humans and mice and may have an impact on C. difficile virulence in the mouse-model of C. difficile infection.

  2. Inhibition of tyrosinase by fumaric acid: Integration of inhibition kinetics with computational docking simulations.

    Science.gov (United States)

    Gou, Lin; Lee, Jinhyuk; Yang, Jun-Mo; Park, Yong-Doo; Zhou, Hai-Meng; Zhan, Yi; Lü, Zhi-Rong

    2017-12-01

    Fumaric acid (FA), which is naturally found in organisms, is a well known intermediate of the citric acid cycle. We evaluated the effects of FA on tyrosinase activity and structure via enzyme kinetics and computational simulations. FA was found to be a reversible inhibitor of tyrosinase and its induced mechanism was the parabolic non-competitive inhibition type with IC 50 =13.7±0.25mM and K i slope =12.64±0.75mM. We newly established the equation for the dissociation constant (K islope ) for the parabolic inhibition type in this study. Kinetic measurements and spectrofluorimetry studies showed that FA induced regional changes in the active site of tyrosinase. One possible binding site for FA was identified under the condition without L-DOPA. The computational docking simulations further revealed that FA can interact with HIS263 and HIS85 at the active site. Furthermore, four important hydrogen bonds were found to be involved with the docking of FA on tyrosinase. Our study provides insight into the mechanism by which dicarboxylic acids such as FA inhibit tyrosinase. By inhibiting tyrosinase and its central role in pigment production, FA is a potential natural antipigmentation agent. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Antimicrobial properties of lactic acid bacteria isolated from uruguayan artisan cheese

    Directory of Open Access Journals (Sweden)

    Martín Fraga Cotelo

    2013-12-01

    Full Text Available Uruguayan artisan cheese is elaborated with raw milk and non-commercial starters. The associated native microbiota may include lactic acid bacteria and also potentially pathogenic bacteria. Lactic acid bacteria were isolated from artisan cheese, raw milk, and non-commercial starter cultures, and their potential bacteriocin production was assessed. A culture collection of 509 isolates was obtained, and five isolates were bacteriocin-producers and were identified as Enterococcus durans,Lactobacillus casei, and Lactococcus lactis. No evidence of potential virulence factors were found in E. durans strains. These are promising results in terms of using these native strains for cheese manufacture and to obtain safe products.

  4. Probiotic lactic acid bacteria – the fledgling cuckoos of the gut?

    Directory of Open Access Journals (Sweden)

    Arnold Berstad

    2016-05-01

    Full Text Available It is tempting to look at bacteria from our human egocentric point of view and label them as either ‘good’ or ‘bad’. However, a microbial society has its own system of government – ‘microcracy’ – and its own rules of play. Lactic acid bacteria are often referred to as representatives of the good ones, and there is little doubt that those belonging to the normal intestinal flora are beneficial for human health. But we should stop thinking of lactic acid bacteria as always being ‘friendly’ – they may instead behave like fledgling cuckoos.

  5. Inhibition studies of soybean (Glycine max) urease with heavy metals, sodium salts of mineral acids, boric acid, and boronic acids.

    Science.gov (United States)

    Kumar, Sandeep; Kayastha, Arvind M

    2010-10-01

    Various inhibitors were tested for their inhibitory effects on soybean urease. The K(i) values for boric acid, 4-bromophenylboronic acid, butylboronic acid, and phenylboronic acid were 0.20 +/- 0.05 mM, 0.22 +/- 0.04 mM, 1.50 +/- 0.10 mM, and 2.00 +/- 0.11 mM, respectively. The inhibition was competitive type with boric acid and boronic acids. Heavy metal ions including Ag(+), Hg(2+), and Cu(2+) showed strong inhibition on soybean urease, with the silver ion being a potent inhibitor (IC(50) = 2.3 x 10(-8) mM). Time-dependent inhibition studies exhibited biphasic kinetics with all heavy metal ions. Furthermore, inhibition studies with sodium salts of mineral acids (NaF, NaCl, NaNO(3), and Na(2)SO(4)) showed that only F(-) inhibited soybean urease significantly (IC(50) = 2.9 mM). Competitive type of inhibition was observed for this anion with a K(i) value of 1.30 mM.

  6. Macrokinetics of magnesium sulfite oxidation inhibited by ascorbic acid.

    Science.gov (United States)

    Lidong, Wang; Yongliang, Ma; Wendi, Zhang; Qiangwei, Li; Yi, Zhao; Zhanchao, Zhang

    2013-08-15

    Magnesia flue gas desulfurization is a promising process for small to medium scale industrial coal-fired boilers in order to reduce sulfur dioxide emissions, in which oxidation control of magnesium sulfite is of great importance for the recycling of products. Effects of four inhibitors were compared by kinetic experiments indicating that ascorbic acid is the best additive, which retards the oxidation process of magnesium sulfite in trace presence. The macrokinetics of magnesium sulfite oxidation inhibited by ascorbic acid were studied. Effects of the factors, including ascorbic acid concentration, magnesium sulfite concentration, oxygen partial pressure, pH, and temperature, were investigated in a stirred reactor with bubbling. The results show that the reaction rate is -0.55 order in ascorbic acid, 0.77 in oxygen partial pressure, and zero in magnesium sulfite concentration, respectively. The apparent activation energy is 88.0 kJ mol(-1). Integrated with the kinetic model, it is concluded that the oxidation rate of magnesium sulfite inhibited by ascorbic acid is controlled by the intrinsic chemical reaction. The result provides a useful reference for sulfite recovery in magnesia desulfurization. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Prospects of recombinant DNA technology in lactic acid bacteria and its application

    Energy Technology Data Exchange (ETDEWEB)

    Kadota, Mariko (Yakult Honsha Co. Ltd., Tokyo (Japan))

    1988-12-25

    This paper outlines recombinational DNA technology which has become feasible recently and uses dairy lactic acid bacteria as the host and discusses the present status of its application. The purpose of studies in this field is to establish host vectors for dairy lactic acid bacteria and raise dairy lactic acid bacteria using recombinational DNA technology as well as the gene structure which is developed by lactic acid bacteria. Recently, energetic effort is being made for these studies on a worldwide scale. Technical lags as compared with techniques in which other bacteria are used as the host are being eliminated. However, it is actually difficult to use bacteria raised using DNA technology. This is because of problems concerning safety which would be impaired when recombined organisms are released into environment and difficulties in obtaining social consensus about such release. In this circumstance, it is important not only to develop appropriate technology, but also to demonstrate the safety of raised bacteria. 29 refs., 3 figs., 3 tabs.

  8. Phenotypic and genotypic characterization of lactic acid bacteria ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-03

    Jun 3, 2009 ... factured at specific ecological localities. These bacteria represent the local .... in portable refrigerator. Bacterial strains, media and ...... An ecological study of lactococci isolated from raw milk in the Camembert cheese registered designation of origin area. Appl. Environ. Microbiol. 64: 4729-4735. Duan Y ...

  9. [Thermoresistance of acid producing psychrotrophic bacteria isolated from milk].

    Science.gov (United States)

    Alfenas, R de C

    1999-03-01

    An acidificant psychrotrophic bacteria was isolated from raw milk from Bromocresol Purple Agar medium, after incubation at 7 degrees C, for 10 days. Cells from the culture, at the beginning of the stationary phase, were inoculated sterilized in powder milk, reconstituted at 12% of total solids, resulting in approximately 10(8) cells per milliliter. Portions of 3 ml of inoculated milk were transferred to borosilicate tubes and were submitted to cells resistance determination at 62, 70, 75 and 80 degrees C, by the TDT tube method. The survival curves at the respective temperatures and the curve of thermal death were drawn. The bacteria presented a D75 degrees C value of 0.15 minutes and z = 8.7 degrees C. Treatments LTLT and HTST of pasteurization promoted 5.27 and 0.53 decimal reductions in the number of available bacteria cells, respectively. The conclusion of this study was that the isolated bacteria is destroyed only by the treatment LTLT of pasteurization.

  10. Screening of malting sorghum samples for lactic acid bacteria with ...

    African Journals Online (AJOL)

    catalase of these inhibitory compounds from the seven bacteria identified them as bacteriocins. Based on standard biochemical and microbiological tests, the isolates were tentatively identified as belonging to Lactococcus spp., Leuconostoc spp., Lactobacillus spp. and Streptococcus spp. However, three isolates (GS3A, ...

  11. Phytase-active lactic acid bacteria from sourdoughs

    DEFF Research Database (Denmark)

    Nuobariene, Lina; Cizeikiene, Dalia; Gradzeviciute, Egle

    2015-01-01

    bacteria (LAB) which could be used as a starter to increase mineral bioavailability in whole-meal bread. Hence, LAB isolates were isolated from Lithuanian sourdoughs, tested for phytase activity, and phytase active isolates were identified. Studies of phytase activity of the isolates were carried out...

  12. Metabolic and functional paths of lactic acid bacteria in plant foods: get out of the labyrinth.

    Science.gov (United States)

    Filannino, Pasquale; Di Cagno, Raffaella; Gobbetti, Marco

    2018-02-01

    Even though lactic acid bacteria are only a small part of the plant autochthonous microbiota, they represent the most important microbes having the capability to promote significant changes in the health-promoting properties of plant foods. Owing to the variety of plant chemical components and the possible pathways for bioconversion, plant fermentation is like a metabolic labyrinth undertaken by bacteria. The winding metabolic pathways involve several secondary plant metabolites (e.g. phenolics). The success of these paths is connected to the adaptive growth and survival of lactic acid bacteria. A panel of various interacting omics approaches unraveled the specific traits of lactic acid bacteria to adapt to plants, which allow the optimal design of fermentation strategies for targeted raw matrices. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Antibacterial Activity of Some Lactic Acid Bacteria Isolated from an Algerian Dairy Product

    Directory of Open Access Journals (Sweden)

    Abdelkader Mezaini

    2009-01-01

    Full Text Available In the present study, the antibacterial effect of 20 lactic acid bacteria isolates from a traditional cheese was investigated. 6 isolates showed antibacterial effect against Gram positive bacteria. Streptococcus thermophilus T2 strain showed the wide inhibitory spectrum against the Gram positive bacteria. Growth and bacteriocin production profiles showed that the maximal bacteriocin production, by S. thermophilus T2 cells, was measured by the end of the late-log phase (90 AU ml−1 with a bacteriocine production rate of 9.3 (AU ml−1 h−1. In addition, our findings showed that the bacteriocin, produced by S. thermophilus T2, was stable over a wide pH range (4–8; this indicates that such bacteriocin may be useful in acidic as well as nonacidic food. This preliminarily work shows the potential application of autochthonous lactic acid bacteria to improve safety of traditional fermented food.

  14. Acid, bile, and heat tolerance of free and microencapsulated probiotic bacteria.

    Science.gov (United States)

    Ding, W K; Shah, N P

    2007-11-01

    Eight strains of probiotic bacteria, including Lactobacillus rhamnosus, Bifidobacterium longum, L. salivarius, L. plantarum, L. acidophilus, L. paracasei, B. lactis type Bl-O4, and B. lactis type Bi-07, were studied for their acid, bile, and heat tolerance. Microencapsulation in alginate matrix was used to enhance survival of the bacteria in acid and bile as well as a brief exposure to heat. Free probiotic organisms were used as a control. The acid tolerance of probiotic organisms was tested using HCl in MRS broth over a 2-h incubation period. Bile tolerance was tested using 2 types of bile salts, oxgall and taurocholic acid, over an 8-h incubation period. Heat tolerance was tested by exposing the probiotic organisms to 65 degrees C for up to 1 h. Results indicated microencapsulated probiotic bacteria survived better (P strains. At 30 min of heat treatment, microencapsulated probiotic bacteria survived with an average loss of only 4.17-log CFU/mL, compared to 6.74-log CFU/mL loss with free probiotic bacteria. However, after 1 h of heating both free and microencapsulated probiotic strains showed similar losses in viability. Overall microencapsulation improved the survival of probiotic bacteria when exposed to acidic conditions, bile salts, and mild heat treatment.

  15. Technology and safety assessment for lactic acid bacteria isolated from traditional Bulgarian fermented meat product "lukanka".

    Science.gov (United States)

    Todorov, Svetoslav Dimitrov; Stojanovski, Saso; Iliev, Ilia; Moncheva, Penka; Nero, Luis Augusto; Ivanova, Iskra Vitanova

    The present work discusses the technological and new selection criteria that should be included for selecting lactic acid bacteria for production of fermented meat. Lactic acid bacteria isolated from Bulgarian traditional fermented "lulanka" salami was studied regarding some positive technological parameters (growth at different temperature, pH, and proteolytic activity). The presence of genes related to the virulence factors, production of biogenic amines, and vancomycin resistance were presented in low frequency in the studied lactic acid bacteria. On the other hand, production of antimicrobial peptides and high spread of bacteriocin genes were broadly presented. Very strong activity against L. monocytogenes was detected in some of the studied lactic acid bacteria. In addition, the studied strains did not present any antimicrobial activity against tested closely related bacteria such as Lactobacillus spp., Lactococcus spp., Enterococcus spp. or Pediococcus spp. To our knowledge this is the first study on the safety and antimicrobial properties of lactic acid bacteria isolated from Bulgarian lukanka obtained by spontaneous fermentation. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  16. Technology and safety assessment for lactic acid bacteria isolated from traditional Bulgarian fermented meat product "lukanka"

    Directory of Open Access Journals (Sweden)

    Svetoslav Dimitrov Todorov

    Full Text Available Abstract The present work discusses the technological and new selection criteria that should be included for selecting lactic acid bacteria for production of fermented meat. Lactic acid bacteria isolated from Bulgarian traditional fermented "lulanka" salami was studied regarding some positive technological parameters (growth at different temperature, pH, and proteolytic activity. The presence of genes related to the virulence factors, production of biogenic amines, and vancomycin resistance were presented in low frequency in the studied lactic acid bacteria. On the other hand, production of antimicrobial peptides and high spread of bacteriocin genes were broadly presented. Very strong activity against L. monocytogenes was detected in some of the studied lactic acid bacteria. In addition, the studied strains did not present any antimicrobial activity against tested closely related bacteria such as Lactobacillus spp., Lactococcus spp., Enterococcus spp. or Pediococcus spp. To our knowledge this is the first study on the safety and antimicrobial properties of lactic acid bacteria isolated from Bulgarian lukanka obtained by spontaneous fermentation.

  17. Control of Listeria monocytogenes in fresh cheese using protective lactic acid bacteria.

    Science.gov (United States)

    Coelho, M C; Silva, C C G; Ribeiro, S C; Dapkevicius, M L N E; Rosa, H J D

    2014-11-17

    In the past years, there has been a particular focus on the application of bacteriocins produced by lactic acid bacteria (LAB) in controlling the growth of pathogenic bacteria in foods. The aim of this study was to select LAB strains with antimicrobial activity, previously isolated from a traditional Azorean artisanal cheese (Pico cheese), in order to identify those with the greatest potential in reducing Listeria monocytogenes in fresh cheese. Eight bacteriocin producer strains identified as Lactococcus lactis (1) and Enterococcus faecalis (7) were tested. In general, the bacteriocin-producing strains presented a moderate growth in fresh cheese at refrigeration temperatures (4 °C), increasing one log count in three days. They exhibited slow acidification capacity, despite the increased production of lactic acid displayed by some strains after 24h. Bacteriocin activity was only detected in the whey of fresh cheese inoculated with two Enterococcus strains, but all cheeses made with bacteriocin-producing strains inhibited L. monocytogenes growth in the agar diffusion bioassay. No significant differences were found in overall sensory evaluation made by a non-trained panel of 50-52 tasters using the isolates as adjunct culture in fresh cheese, with the exception of one Enterococcus strain. To test the effect of in situ bacteriocin production against L. monocytogenes, fresh cheese was made from pasteurized cows' milk inoculated with bacteriocin-producing LAB and artificially contaminated with approximately 10(6) CFU/mL of L. monocytogenes. The numbers of L. monocytogenes were monitored during storage of fresh cheese at refrigeration temperature (4 °C) for up to 15 days. All strains controlled the growth of L. monocytogenes, although some Enterococcus were more effective in reducing the pathogen counts. After 7 days, this reduction was of approximately 4 log units compared to the positive control. In comparison, an increase of 4 log CFU/mL in pathogen numbers was

  18. Endophytic Bacteria Isolated from Common Bean (Phaseolus vulgaris) Exhibiting High Variability Showed Antimicrobial Activity and Quorum Sensing Inhibition.

    Science.gov (United States)

    Lopes, Ralf Bruno Moura; Costa, Leonardo Emanuel de Oliveira; Vanetti, Maria Cristina Dantas; de Araújo, Elza Fernandes; de Queiroz, Marisa Vieira

    2015-10-01

    Endophytic bacteria play a key role in the biocontrol of phytopathogenic microorganisms. In this study, genotypic diversity was analyzed via repetitive element PCR (rep-PCR) of endophytic isolates of the phylum Actinobacteria that were previously collected from leaves of cultivars of common bean (Phaseolus vulgaris). Considerable variability was observed, which has not been reported previously for this phylum of endophytic bacteria of the common bean. Furthermore, the ethanol extracts from cultures of various isolates inhibited the growth of pathogenic bacteria in vitro, especially Gram-positive pathogens. Extracts from cultures of Microbacterium testaceum BAC1065 and BAC1093, which were both isolated from the 'Talismã' cultivar, strongly inhibited most of the pathogenic bacteria tested. Bean endophytic bacteria were also demonstrated to have the potential to inhibit the quorum sensing of Gram-negative bacteria. This mechanism may regulate the production of virulence factors in pathogens. The ability to inhibit quorum sensing has also not been reported previously for endophytic microorganisms of P. vulgaris. Furthermore, M. testaceum with capacity to inhibit quorum sensing appears to be widespread in common bean. The genomic profiles of M. testaceum were also analyzed via pulsed-field gel electrophoresis, and greater differentiation was observed using this method than rep-PCR; in general, no groups were formed based on the cultivar of origin. This study showed for the first time that endophytic bacteria from common bean plants exhibit high variability and may be useful for the development of strategies for the biological control of diseases in this important legume plant.

  19. Metabolism of Fructophilic Lactic Acid Bacteria Isolated from the Apis mellifera L. Bee Gut: Phenolic Acids as External Electron Acceptors

    Science.gov (United States)

    Filannino, Pasquale; Addante, Rocco; Pontonio, Erica; Gobbetti, Marco

    2016-01-01

    ABSTRACT Fructophilic lactic acid bacteria (FLAB) are strongly associated with the gastrointestinal tracts (GITs) of Apis mellifera L. worker bees due to the consumption of fructose as a major carbohydrate. Seventy-seven presumptive lactic acid bacteria (LAB) were isolated from GITs of healthy A. mellifera L. adults, which were collected from 5 different geographical locations of the Apulia region of Italy. Almost all of the isolates showed fructophilic tendencies: these isolates were identified as Lactobacillus kunkeei (69%) or Fructobacillus fructosus (31%). A high-throughput phenotypic microarray targeting 190 carbon sources was used to determine that 83 compounds were differentially consumed. Phenotyping grouped the strains into two clusters, reflecting growth performance. The utilization of phenolic acids, such as p-coumaric, caffeic, syringic, or gallic acids, as electron acceptors was investigated in fructose-based medium. Almost all FLAB strains showed tolerance to high phenolic acid concentrations. p-Coumaric acid and caffeic acid were consumed by all FLAB strains through reductases or decarboxylases. Syringic and gallic acids were partially metabolized. The data collected suggest that FLAB require external electron acceptors to regenerate NADH. The use of phenolic acids as external electron acceptors by the 4 FLAB showing the highest phenolic acid reductase activity was investigated in glucose-based medium supplemented with p-coumaric acid. Metabolic responses observed through a phenotypic microarray suggested that FLAB may use p-coumaric acid as an external electron acceptor, enhancing glucose dissimilation but less efficiently than other external acceptors such as fructose or pyruvic acid. IMPORTANCE Fructophilic lactic acid bacteria (FLAB) remain to be fully explored. This study intends to link unique biochemical features of FLAB with their habitat. The quite unique FLAB phenome within the group lactic acid bacteria (LAB) may have practical relevance

  20. New potentially antihypertensive peptides liberated in milk during fermentation with selected lactic acid bacteria and kombucha cultures.

    Science.gov (United States)

    Elkhtab, Ebrahim; El-Alfy, Mohamed; Shenana, Mohamed; Mohamed, Abdelaty; Yousef, Ahmed E

    2017-12-01

    Compounds with the ability to inhibit angiotensin-converting enzyme (ACE) are used medically to treat human hypertension. The presence of such compounds naturally in food is potentially useful for treating the disease state. The goal of this study was to screen lactic acid bacteria, including species commonly used as dairy starter cultures, for the ability to produce new potent ACE-inhibiting peptides during milk fermentation. Strains of Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus helveticus, Lactobacillus paracasei, Lactococcus lactis, Leuconostoc mesenteroides, and Pediococcus acidilactici were tested in this study. Additionally, a symbiotic consortium of yeast and bacteria, used commercially to produce kombucha tea, was tested. Commercially sterile milk was inoculated with lactic acid bacteria strains and kombucha culture and incubated at 37°C for up to 72 h, and the liberation of ACE-inhibiting compounds during fermentation was monitored. Fermented milk was centrifuged and the supernatant (crude extract) was subjected to ultrafiltration using 3- and 10-kDa cut-off filters. Crude and ultrafiltered extracts were tested for ACE-inhibitory activity. The 10-kDa filtrate resulting from L. casei ATCC 7469 and kombucha culture fermentations (72 h) showed the highest ACE-inhibitory activity. Two-step purification of these filtrates was done using HPLC equipped with a reverse-phase column. Analysis of HPLC-purified fractions by liquid chromatography-mass spectrometry/mass spectrometry identified several new peptides with potent ACE-inhibitory activities. Some of these peptides were synthesized, and their ACE-inhibitory activities were confirmed. Use of organisms producing these unique peptides in food fermentations could contribute positively to human health. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  1. Lactic acid bacteria in the quality improvement and depreciation of wine.

    Science.gov (United States)

    Lonvaud-Funel, A

    1999-01-01

    The winemaking process includes two main steps: lactic acid bacteria are responsible for the malolactic fermentation which follows the alcoholic fermentation by yeasts. Both types of microorganisms are present on grapes and on cellar equipment. Yeasts are better adapted to growth in grape must than lactic acid bacteria, so the alcoholic fermentation starts quickly. In must, up to ten lactic acid bacteria species can be identified. They belong to the Lactobacillus, Pediococcus, Leuconostoc and Oenococcus genera. Throughout alcoholic fermentation, a natural selection occurs and finally the dominant species is O. oeni, due to interactions between yeasts and bacteria and between bacteria themselves. After bacterial growth, when the population is over 10(6) CFU/ml, malolactic transformation is the obvious change in wine composition. However, many other substrates can be metabolized. Some like remaining sugars and citric acid are always assimilated by lactic acid bacteria, thus providing them with energy and carbon. Other substrates such as some amino acids may be used following pathways restricted to strains carrying the adequate enzymes. Some strains can also produce exopolysaccharides. All these transformations greatly influence the sensory and hygienic quality of wine. Malic acid transformation is encouraged because it induces deacidification. Diacetyl produced from citric acid is also helpful to some extent. Sensory analyses show that many other reactions change the aromas and make malolactic fermentation beneficial, but they are as yet unknown. On the contrary, an excess of acetic acid, the synthesis of glucane, biogenic amines and precursors of ethylcarbamate are undesirable. Fortunately, lactic acid bacteria normally multiply in dry wines; moreover some of these activities are not widespread. Moreover, the most striking trait of wine lactic acid bacteria is their capacity to adapt to a hostile environment. The mechanisms for this are not yet completely elucidated

  2. In vitro evaluation of bacteriocin-like inhibitory substances produced by lactic acid bacteria isolated during traditional Sicilian cheese making

    Directory of Open Access Journals (Sweden)

    Giusi Macaluso

    2016-02-01

    Full Text Available Bacteriocins are antimicrobial proteins produced by bacteria that inhibit the growth of other bacteria with a bactericidal or bacteriostatic mode of action. Many lactic acid bacteria (LAB produce a high diversity of different bacteriocins. Bacteriocinogenic LAB are generally recognised as safe (GRAS and useful to control the frequent development of pathogens and spoilage microorganisms. For this reason they are commonly used as starter cultures in food fermentations. In this study, the authors describe the results of a screening on 699 LAB isolated from wooden vat surfaces, raw milk and traditional Sicilian cheeses, for the production of bacteriocin-like inhibitory substances, by comparing two alternative methods. The antagonistic activity of LAB and its proteinaceous nature were evaluated using the spot-on-the-lawn and the well-diffusion assay (WDA and the sensitivity to proteolytic (proteinase K, protease B and trypsin, amylolytic (α-amylase and lipolytic (lipase enzymes. The indicator strains used were: Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, Salmonella enteritidis. A total of 223 strains (belonging to the species Enterococcus spp., Lactobacillus spp., Pediococcus spp., Streptococcus spp., Leuconostoc spp. and Lactococcus lactis were found to inhibit the growth of Listeria monocytogenes by using the spot-on-the-lawn method; only 37 of these were confirmed by using the WDA. The direct addition of bacteriocin-producing cultures into dairy products can be a more practical and economic option for the improvement of the safety and quality of the final product.

  3. The use of naturally occurring selectively isolated bacteria for inhibiting paraffin deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lazar, I.; Voicu, A.; Dobrota, S.; Petrisor, I.G.; Stefanescu, M.; Sandulescu, L. [Institute of Biology of the Romanian Academy, Spl. Independentei 296, Bucharest (Romania); Nicolescu, C.; Mucenica, D. [PETROSTAR Ploiesti, Bdul Bucuresti 35, Ploiesti (Romania)

    1999-01-01

    One of the most severe problems at any oil fields producing paraffinic oils is that of paraffin depositions. Romania which has a long experience in oil production is also faced with this problem in many oil fields. The microbial treatment, based on the activity of naturally occurring, selectively isolated bacteria, is already proved as an effective alternative to conventional methods to prevent and remove paraffin damage. Using such kind of bacterial products, exciting results for inhibiting paraffin depositions have been obtained. In this paper results concerning the naturally occurring bacteria selectively isolated from hydrocarbon polluted sites as well as from paraffinic oils, semi-solid and solid paraffin depositions are presented. After a laboratory screening, 15 bacterial strains (BS 1-15), three bacterial consortia (BC 1-3) and a Special Bacterial Consortium (SBC1) were selected. For the selection of bacterial consortia, the classical enrichment culture method has been used. The Special Bacterial Consortium resulted from a mixture of BS 1-15 and BC 1-3 following the steps of the classical enrichment culture method. The BS 1-15, BC 1-3 and SBC1 have been tested for their performances in producing biosurfactants and biosolvents as well as for hydrocarbon utilisation. The SBC1 has been tested for its ability in degradation of hydrocarbons contained in several types of paraffinic or non-paraffinic oils, and then for inhibiting paraffin deposition on a `flow equipment` using two types of paraffinic oils. The SBC1 has been also tested for degradation of hydrocarbons contained in semi-solid and solid paraffin depositions. The results obtained could support further applications to prevent and control paraffin depositions

  4. The use of naturally occurring selectively isolated bacteria for inhibiting paraffin deposition

    International Nuclear Information System (INIS)

    Lazar, I.; Voicu, A.; Dobrota, S.; Petrisor, I.G.; Stefanescu, M.; Sandulescu, L.; Nicolescu, C.; Mucenica, D.

    1999-01-01

    One of the most severe problems at any oil fields producing paraffinic oils is that of paraffin depositions. Romania which has a long experience in oil production is also faced with this problem in many oil fields. The microbial treatment, based on the activity of naturally occurring, selectively isolated bacteria, is already proved as an effective alternative to conventional methods to prevent and remove paraffin damage. Using such kind of bacterial products, exciting results for inhibiting paraffin depositions have been obtained. In this paper results concerning the naturally occurring bacteria selectively isolated from hydrocarbon polluted sites as well as from paraffinic oils, semi-solid and solid paraffin depositions are presented. After a laboratory screening, 15 bacterial strains (BS 1-15), three bacterial consortia (BC 1-3) and a Special Bacterial Consortium (SBC1) were selected. For the selection of bacterial consortia, the classical enrichment culture method has been used. The Special Bacterial Consortium resulted from a mixture of BS 1-15 and BC 1-3 following the steps of the classical enrichment culture method. The BS 1-15, BC 1-3 and SBC1 have been tested for their performances in producing biosurfactants and biosolvents as well as for hydrocarbon utilisation. The SBC1 has been tested for its ability in degradation of hydrocarbons contained in several types of paraffinic or non-paraffinic oils, and then for inhibiting paraffin deposition on a 'flow equipment' using two types of paraffinic oils. The SBC1 has been also tested for degradation of hydrocarbons contained in semi-solid and solid paraffin depositions. The results obtained could support further applications to prevent and control paraffin depositions

  5. Screening of Lactic Acid Bacteria from Rumen Liquor and King Grass Silage as well as Their Antibacterial Activities

    Directory of Open Access Journals (Sweden)

    A. Sofyan

    2013-12-01

    Full Text Available Probiotic is a live microbial culture which has positive effect on animal by improving the natural balance of microflora in the digestive tract. This experiment aimed to screen and identify indigenous lactic acid bacteria (LAB from rumen liquor and king grass (Pennisetum hybrid silage as a probiotic candidate and to evaluate their resistance in low pH, and inhibitory activities against pathogenic bacteria. The LAB isolate was characterized by a clear zone formed on MRSA medium + CaCO3 0.2% (w/v and further identified by morphological and biochemical assays. The selected isolates were evaluated for their viability in low pH, pathogenic bacterial inhibition, and lactic acid production. The experimental arrangement was a factorial block design (4 x 2 consisted of four isolates and two levels of pH value (pH 2 and 3, each treatment in 3 equal replicates. The result showed that four isolates (two isolates from the rumen liquor of fistulated cattle and two isolates from silage were identified as lactic acid bacteria. The four isolates showed inhibition activity against Escherichia coli, Bacillus subtilis, Staphylococcus aureus and performed viability at low pH during 2 h treatment. The highest lactic acid production was obtained from isolates Sil.3 (21.42% and followed by CR2 (19.88%, CR1 (15.40% and Sil.9 (15.08%. Biochemical identification by standard of analytical profile index (API 50 CHL kit showed that the selected isolates CR1 was Lactobacillus paracasei ssp. paracasei 3 (91.5%, L. paracasei ssp. paracasei 3 (76.5%, Sil.3 was Lactobacillus brevis (95.1%, and Sil.9 was Lactobacillus collinoides (92.5%. In conclusion, probiotic candidates isolated from rumen liquor are confirmed as L. paracasei ssp. paracasei (CR1 and CR2, while two other isolates from king grass silage are identified as L. brevis (Sil.3 and L. collinoides (Sil.9. L. brevis (Sil.3 and L. paracasei ssp. paracasei (CR1 has higher inhibition against pathogenic bacteria (E. coli, S

  6. Evaluation of ginsenoside bioconversion of lactic acid bacteria isolated from kimchi

    Directory of Open Access Journals (Sweden)

    Boyeon Park

    2017-10-01

    Conclusion: Ginsenoside Rg5 concentration of five LABs have ranged from ∼2.6 μg/mL to 6.5 μg/mL and increased in accordance with the incubation periods. Our results indicate that the enzymatic activity along with acidic condition contribute to the production of minor ginsenoside from lactic acid bacteria.

  7. Isolation of Lactic Acid Bacteria That Produce Protease and Bacteriocin-Like Substance From Mud Crab (Scylla sp. Digestive Tract (Isolasi Bakteri Asam Laktat yang Menghasilkan Protease dan Senyawa Bacteriocin-Like dari Saluran Pencernaan Kepiting

    Directory of Open Access Journals (Sweden)

    Heru Pramono

    2015-03-01

    Kata kunci: Bakteri Asam Laktat, Bakteriosin-like substance, Protease, Scylla  sp. Digestive tract is complex environment consist of large amount of bacteria’s species. Fish intestine bacteria consist of aerobic or facultative anaerob bacteria which can produce antibacterial and enzym. The objectives of this research were to isolated lactic acid bacteria that produce bacteriocin-like and protease from mud crab digestive tract. Isolation and characterization of isolates were conducted employing media MRS.  Neutralized cell free supernatant of isolates were tested using disc diffusion agar of against pathogenic and spoilage bacteria to indicate bacteriocin-like-producing lactic acid bacteria. Protease-producing isolate was tested using disc diffusion method in casein agar. Among a hundred isolates, 96 isolates were showed clear zone in MRS+CaCO3,, catalase negative, and Gram positive bacteria. Thirty four isolates produced protease and only four isolates (i.e. IKP29, IKP30, IKP52, and IKP94 showed strong inhibition against pathogenic and spoilage bacteria. There were three patterns of inhibition among three isolates against Bacillus subtilis, Staphylococcus aureus, Eschericia coli, and Salmonella sp. All three isolates showed potential uses for produce starter culture for fishery product fermentation purpose. This is the first report of isolation lactic acid bacteria that produced protease and bacteriocin-like from digestive tract of mud crab. Keywords: Lactic acid bacteria, Bacteriocin-like substance, Protease, Scylla  sp.

  8. Lactic acid bacteria as a cell factory for riboflavin production

    OpenAIRE

    Thakur, Kiran; Tomar, Sudhir Kumar; De, Sachinandan

    2015-01-01

    Summary Consumers are increasingly becoming aware of their health and nutritional requirements, and in this context, vitamins produced in situ by microbes may suit their needs and expectations. B groups vitamins are essential components of cellular metabolism and among them riboflavin is one of the vital vitamins required by bacteria, plants, animals and humans. Here, we focus on the importance of microbial production of riboflavin over chemical synthesis. In addition, genetic abilities for r...

  9. 10-oxo-12(Z)-octadecenoic acid, a linoleic acid metabolite produced by gut lactic acid bacteria, potently activates PPARγ and stimulates adipogenesis.

    Science.gov (United States)

    Goto, Tsuyoshi; Kim, Young-Il; Furuzono, Tomoya; Takahashi, Nobuyuki; Yamakuni, Kanae; Yang, Ha-Eun; Li, Yongjia; Ohue, Ryuji; Nomura, Wataru; Sugawara, Tatsuya; Yu, Rina; Kitamura, Nahoko; Park, Si-Bum; Kishino, Shigenobu; Ogawa, Jun; Kawada, Teruo

    2015-04-17

    Our previous study has shown that gut lactic acid bacteria generate various kinds of fatty acids from polyunsaturated fatty acids such as linoleic acid (LA). In this study, we investigated the effects of LA and LA-derived fatty acids on the activation of peroxisome proliferator-activated receptors (PPARs) which regulate whole-body energy metabolism. None of the fatty acids activated PPARδ, whereas almost all activated PPARα in luciferase assays. Two fatty acids potently activated PPARγ, a master regulator of adipocyte differentiation, with 10-oxo-12(Z)-octadecenoic acid (KetoA) having the most potency. In 3T3-L1 cells, KetoA induced adipocyte differentiation via the activation of PPARγ, and increased adiponectin production and insulin-stimulated glucose uptake. These findings suggest that fatty acids, including KetoA, generated in gut by lactic acid bacteria may be involved in the regulation of host energy metabolism. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Effects of culture conditions on acetic acid production by bacteria ...

    African Journals Online (AJOL)

    SARAH

    2015-11-30

    Nov 30, 2015 ... implicated in conversion of ethanol into acetic acid. (Tayama et al., 1989). Therefore, incapacity of these strains to produce acetic acid at 45 °C is probably due to several factors unexplained in our knowledge especially since Moghadami et al. (2013) have demonstrated that thermotolerant strains have high.

  11. On the amino acid esters of phosphatidyl glycerol from bacteria

    NARCIS (Netherlands)

    Houtsmuller, U.M.T.; Deenen, L.L.M. van

    1965-01-01

    1. 1. The phospholipids of Staphylococcus aureus were fractionated on silicic acid columns. The major compounds all appeared to be polyglycerol lipids. Diphosphatidyl glycerol and phosphatidyl glycerol were identified by comparison with the synthetic phospholipids. 2. 2. An amino acid derivative

  12. Effects of culture conditions on acetic acid production by bacteria ...

    African Journals Online (AJOL)

    SARAH

    2015-11-30

    Nov 30, 2015 ... Wheals, 2004; Romero-Cortes et al., 2012). Generally, AAB emerged after 24 h of fermentation when air comes in fermentation heap (Nielsen et al., 2007) and then oxidize ethanol previously produced by yeasts to acetic acid by exothermic reaction. This acid diffuses into beans and in combination with heat ...

  13. Effects of culture conditions on acetic acid production by bacteria ...

    African Journals Online (AJOL)

    Objectives: This study investigates the acidification capacity under various culture conditions of high acetic acid producer AAB strains previously isolated from Ivoirian cocoa beans fermentation. Methodology and Results: Effect of culture conditions was studied in agar medium and acid production was monitored by ...

  14. Characterization of lactic acid bacteria isolated from poultry farms in ...

    African Journals Online (AJOL)

    The Lactobacilli strains, both isolated from faeces, produced higher amounts of cells and lactic acid from soils as compared to the lactococci strain isolated from feathers. L (+)-lactic acid is the only optical isomer for use in pharmaceutical and food industries because is only adapted to assimilate this form. The optical isomers ...

  15. A Consistent Methodology Based Parameter Estimation for a Lactic Acid Bacteria Fermentation Model

    DEFF Research Database (Denmark)

    Spann, Robert; Roca, Christophe; Kold, David

    2017-01-01

    Lactic acid bacteria are used in many industrial applications, e.g. as starter cultures in the dairy industry or as probiotics, and research on their cell production is highly required. A first principles kinetic model was developed to describe and understand the biological, physical, and chemical...... mechanisms in a lactic acid bacteria fermentation. We present here a consistent approach for a methodology based parameter estimation for a lactic acid fermentation. In the beginning, just an initial knowledge based guess of parameters was available and an initial parameter estimation of the complete set...

  16. Kinetic analysis of strains of lactic acid bacteria and acetic acid bacteria in cocoa pulp simulation media toward development of a starter culture for cocoa bean fermentation.

    Science.gov (United States)

    Lefeber, Timothy; Janssens, Maarten; Camu, Nicholas; De Vuyst, Luc

    2010-12-01

    The composition of cocoa pulp simulation media (PSM) was optimized with species-specific strains of lactic acid bacteria (PSM-LAB) and acetic acid bacteria (PSM-AAB). Also, laboratory fermentations were carried out in PSM to investigate growth and metabolite production of strains of Lactobacillus plantarum and Lactobacillus fermentum and of Acetobacter pasteurianus isolated from Ghanaian cocoa bean heap fermentations, in view of the development of a defined starter culture. In a first step, a selection of strains was made out of a pool of strains of these LAB and AAB species, obtained from previous studies, based on their fermentation kinetics in PSM. Also, various concentrations of citric acid in the presence of glucose and/or fructose (PSM-LAB) and of lactic acid in the presence of ethanol (PSM-AAB) were tested. These data could explain the competitiveness of particular cocoa-specific strains, namely, L. plantarum 80 (homolactic and acid tolerant), L. fermentum 222 (heterolactic, citric acid fermenting, mannitol producing, and less acid tolerant), and A. pasteurianus 386B (ethanol and lactic acid oxidizing, acetic acid overoxidizing, acid tolerant, and moderately heat tolerant), during the natural cocoa bean fermentation process. For instance, it turned out that the capacity to use citric acid, which was exhibited by L. fermentum 222, is of the utmost importance. Also, the formation of mannitol was dependent not only on the LAB strain but also on environmental conditions. A mixture of L. plantarum 80, L. fermentum 222, and A. pasteurianus 386B can now be considered a mixed-strain starter culture for better controlled and more reliable cocoa bean fermentation processes.

  17. AKTIVITAS ANTIKAPANG BAKTERI ASAM LAKTAT TERHADAP PERTUMBUHAN KAPANG KONTAMINAN KEJI [Antimycotic Activity of Lactic Acid Bacteria on the Growth of Cheese Contaminating Molds

    Directory of Open Access Journals (Sweden)

    S. Styahadi3

    2006-04-01

    Full Text Available Local cheese is frequently contaminated by toxigenic molds which is harmful for human health. Lactic acid bacteria have been proven to inhibit the growth of toxigenic mold in some food products. The research was aimed to study the activity of indigenous lactic acid bacteria to inhibit the growth of toxigenic molds in local cheese. The molds studied were isolated from local cheese production (Gouda type. The cheese contaminating molds were identified as Penicillium sp. and Aspergillus sp. Nine species of indigenous lactic acid bacteria (LAB were tested for antimycotic activities, i.e. Lactobacillus plantarum kik, Lactobacillus plantarum sa, Lactobacillus plantarum pi28a, Lactobacillus plantarum dd, Lactobacillus coryneformis, Lactobacillus brevis, Lactococcus piscium, Leuconostoc mesenteroides, and Leuconostoc paramesenteroides. The research revealed that the promising indigenous LAB which inhibited the contaminating molds was Lb plantarum pi28a. Application of Lb plantarum pi28a on local cheese production could inhibit the growth of Penicillium sp. and Aspergillus sp. up to 12 days.

  18. Extraction, isolation and purification of exopolysaccharide from lactic acid bacteria using ethanol precipitation method

    Directory of Open Access Journals (Sweden)

    Vivek K. Bajpai

    2016-09-01

    Full Text Available Lactic acid bacteria are classified ‘Generally Recognized As Safe’ (GRAS with most effective potential to divert significant amount of fermentable sugars towards the biosynthesis of functional exopolysaccharide. Exopolysaccharides from lactic acid bacteria are receiving a renewed interest due to the claims of human health benefits, such as modulation of immune response system and more importantly in food and pharma industries as a texturizer, viscosifer, emulsifier and syneresis-lowering agent. Its purification methodology involves: a Extraction of cell-free supernatant from lactic acid bacteria; b Denature of protein using trichloroacetic acid; c Ethanol precipitation; d Dialysis; and e Freeze drying. However, depending on nature of research, compounds can be further purified using scanning electron microscopy (SEM, infrared spectrum (IR; and nuclear magnetic resonance (NMR spectral analyses.

  19. Tyrosinase Inhibitory and Anti-oxidative Effects of Lactic Acid Bacteria Isolated from Dairy Cow Feces.

    Science.gov (United States)

    Ji, Keunho; Cho, Youn Su; Kim, Young Tae

    2018-03-01

    Overproduction and accumulation of melanin cause a number of skin diseases. The inhibitors of tyrosinase are important for the treatment of skin diseases associated with hyper-pigmentation after UV exposure and application in cosmetics for whitening and depigmentation. Reactive oxygen species (ROS) including hydrogen peroxide are generated by chemical substances and metabolic intermediates and cause various diseases including cancer and heart diseases. We have isolated four different lactic acid bacteria (LAB) strains from dairy cow feces and investigated the tyrosinase inhibition and anti-oxidative effects of culture filtrates prepared from the isolated bacteria, which are designated as EA3, EB2, PC2, and PD3. To investigate optimal culture conditions isolated LAB strains, the measurements of tyrosinase inhibitory and anti-oxidative activities were performed. The results of tyrosinase inhibitory activities revealed that Enterococcus sp. EA3 showed about 65% at culture conditions (14 h, 30 °C, pH 8, and 0% NaCl), Enterococcus sp. EB2 about 65% at culture conditions (12 h, 30 °C, pH 9, and 0% NaCl), Pediococcus sp. PC2 about 80% at culture conditions (20 h, 30 °C, pH 6, and 0% NaCl), and Pediococcus sp. PD3 about 80% at culture conditions (20 h, 30 °C, pH 8, and 0% NaCl), respectively. In addition, anti-oxidative activities against four different LAB strains showed approximately more than 30% at optimal conditions for the measurements of tyrosinase inhibitory activities. From the results, we have suggested that the isolated four LAB strains could be useful for a potential agent for developing anti-oxidants and tyrosinase inhibitors.

  20. Accelerated wound healing in mice by on-site production and delivery of CXCL12 by transformed lactic acid bacteria.

    Science.gov (United States)

    Vågesjö, Evelina; Öhnstedt, Emelie; Mortier, Anneleen; Lofton, Hava; Huss, Fredrik; Proost, Paul; Roos, Stefan; Phillipson, Mia

    2018-02-20

    Impaired wound closure is a growing medical problem associated with metabolic diseases and aging. Immune cells play important roles in wound healing by following instructions from the microenvironment. Here, we developed a technology to bioengineer the wound microenvironment and enhance healing abilities of the immune cells. This resulted in strongly accelerated wound healing and was achieved by transforming Lactobacilli with a plasmid encoding CXCL12. CXCL12-delivering bacteria administrated topically to wounds in mice efficiently enhanced wound closure by increasing proliferation of dermal cells and macrophages, and led to increased TGF-β expression in macrophages. Bacteria-produced lactic acid reduced the local pH, which inhibited the peptidase CD26 and consequently enhanced the availability of bioactive CXCL12. Importantly, treatment with CXCL12-delivering Lactobacilli also improved wound closure in mice with hyperglycemia or peripheral ischemia, conditions associated with chronic wounds, and in a human skin wound model. Further, initial safety studies demonstrated that the topically applied transformed bacteria exerted effects restricted to the wound, as neither bacteria nor the chemokine produced could be detected in systemic circulation. Development of drugs accelerating wound healing is limited by the proteolytic nature of wounds. Our technology overcomes this by on-site chemokine production and reduced degradation, which together ensure prolonged chemokine bioavailability that instructed local immune cells and enhanced wound healing. Copyright © 2018 the Author(s). Published by PNAS.

  1. Cadmium inhibits acid secretion in stimulated frog gastric mucosa

    International Nuclear Information System (INIS)

    Gerbino, Andrea; Debellis, Lucantonio; Caroppo, Rosa; Curci, Silvana; Colella, Matilde

    2010-01-01

    Cadmium, a toxic environmental pollutant, affects the function of different organs such as lungs, liver and kidney. Less is known about its toxic effects on the gastric mucosa. The aim of this study was to investigate the mechanisms by which cadmium impacts on the physiology of gastric mucosa. To this end, intact amphibian mucosae were mounted in Ussing chambers and the rate of acid secretion, short circuit current (I sc ), transepithelial potential (V t ) and resistance (R t ) were recorded in the continuous presence of cadmium. Addition of cadmium (20 μM to 1 mM) on the serosal but not luminal side of the mucosae resulted in inhibition of acid secretion and increase in NPPB-sensitive, chloride-dependent short circuit current. Remarkably, cadmium exerted its effects only on histamine-stimulated tissues. Experiments with TPEN, a cell-permeant chelator for heavy metals, showed that cadmium acts from the intracellular side of the acid secreting cells. Furthermore, cadmium-induced inhibition of acid secretion and increase in I sc cannot be explained by an action on: 1) H 2 histamine receptor, 2) Ca 2+ signalling 3) adenylyl cyclase or 4) carbonic anhydrase. Conversely, cadmium was ineffective in the presence of the H + /K + -ATPase blocker omeprazole suggesting that the two compounds likely act on the same target. Our findings suggest that cadmium affects the functionality of histamine-stimulated gastric mucosa by inhibiting the H + /K + -ATPase from the intracellular side. These data shed new light on the toxic effect of this dangerous environmental pollutant and may result in new avenues for therapeutic intervention in acute and chronic intoxication.

  2. In Vitro Characterization of Lactic Acid Bacteria Isolated from Bovine Milk as Potential Probiotic Strains to Prevent Bovine Mastitis.

    Science.gov (United States)

    Pellegrino, Matías S; Frola, Ignacio D; Natanael, Berardo; Gobelli, Dino; Nader-Macias, María E F; Bogni, Cristina I

    2018-01-02

    Bovine mastitis causes economic losses on dairy farms worldwide. Lactic acid bacteria (LAB) in animal health are an alternative tool to avoid antibiotic therapy on the prevention of bovine mastitis. In previous studies, 12 LAB isolated from bovine milk were selected taking into account some of the following characteristics: hydrophobicity, auto aggregative capability, inhibition of indicator pathogens, hydrogen peroxide, and capsular polysaccharide production. These LAB were considered because of their beneficial properties. In this work, we also analyzed the antimicrobial activity and the co-aggregation against mastitis causing bacteria, auto-inhibition, adhesion to bovine teat canal epithelial cells (BTCEC), and growth kinetic curves for the 12 LAB. Two of them, Lactococcus lactis subsp. lactis CRL 1655 and Lactobacillus perolens CRL 1724, were selected because they had an interesting pattern of adhesion to BTEC, the inhibition of pathogens and the co-aggregation with the 100% of the assayed pathogens. They showed a predictable difference in the PFGE genomic pattern bands. The kinetic growth of these two strains was similar between them and with the rest of the assayed LAB. The strains selected in the present study showed indispensable characteristics for their inclusion in a probiotic formulation to be used at dry-off period for the prevention of bovine mastitis.

  3. Intestinal bacteria in charge of radiation-induced inhibition of tumor metastases

    International Nuclear Information System (INIS)

    Ando, K.; Matsumoto, T.; Koike, S.

    1984-01-01

    The authors previously reported that caecal irradiation prior to an i.v. challenge of tumor cells inhibited lung metastases formation. The authors here identified bacteria in charge of the radiation effect and reported kinetics of bacterial flora after abdominal irradiation. C3Hf/He male mice in either SPF, germ-free or gnotobiotic condition received abdominal irradiation with /sup 137/Cs γ-ray of 12 Gy and received an i.v. challenge of 10 fibrosarcoma (NFSa) 7 days thereafter. Gnotobiotes which were mono-associated with Enterobacter cloacae(Ent. cloacae) showed significantly smaller number of lung metastases than germ-free mice while monoassociation with Bifidobacilli failed to exert any inhibition. In SPF mice, Ent. cloacae translocated to mesenteric lymph nodes at day 5 to 7 of irradiation while Bifidobacilli and Lactobacili were detectable only at day 14. Considering that Ent. cloacae possess endotoxin while Bifidobacilli and Lactobacilli do not, abdominal irradiation probably releases endotoxin from caecum to the rest of the body, resulting in stimulation of the host defence mechanism against metastases

  4. Screening of antimicrobial activity of lactic acid bacteria isolated ...

    African Journals Online (AJOL)

    conducted under the appropriated hygiene and safety standards could help reducing diarrheal diseases and thus ensure the well-being of children 0 to 5 years old. The objective of this work was therefore to identify and characterize LAB isolated from anango baca slurry, able to inhibit the growth of pathogens and food ...

  5. Dynamics and Biodiversity of Populations of Lactic Acid Bacteria and Acetic Acid Bacteria Involved in Spontaneous Heap Fermentation of Cocoa Beans in Ghana▿

    Science.gov (United States)

    Camu, Nicholas; De Winter, Tom; Verbrugghe, Kristof; Cleenwerck, Ilse; Vandamme, Peter; Takrama, Jemmy S.; Vancanneyt, Marc; De Vuyst, Luc

    2007-01-01

    The Ghanaian cocoa bean heap fermentation process was studied through a multiphasic approach, encompassing both microbiological and metabolite target analyses. A culture-dependent (plating and incubation, followed by repetitive-sequence-based PCR analyses of picked-up colonies) and culture-independent (denaturing gradient gel electrophoresis [DGGE] of 16S rRNA gene amplicons, PCR-DGGE) approach revealed a limited biodiversity and targeted population dynamics of both lactic acid bacteria (LAB) and acetic acid bacteria (AAB) during fermentation. Four main clusters were identified among the LAB isolated: Lactobacillus plantarum, Lactobacillus fermentum, Leuconostoc pseudomesenteroides, and Enterococcus casseliflavus. Other taxa encompassed, for instance, Weissella. Only four clusters were found among the AAB identified: Acetobacter pasteurianus, Acetobacter syzygii-like bacteria, and two small clusters of Acetobacter tropicalis-like bacteria. Particular strains of L. plantarum, L. fermentum, and A. pasteurianus, originating from the environment, were well adapted to the environmental conditions prevailing during Ghanaian cocoa bean heap fermentation and apparently played a significant role in the cocoa bean fermentation process. Yeasts produced ethanol from sugars, and LAB produced lactic acid, acetic acid, ethanol, and mannitol from sugars and/or citrate. Whereas L. plantarum strains were abundant in the beginning of the fermentation, L. fermentum strains converted fructose into mannitol upon prolonged fermentation. A. pasteurianus grew on ethanol, mannitol, and lactate and converted ethanol into acetic acid. A newly proposed Weissella sp., referred to as “Weissella ghanaensis,” was detected through PCR-DGGE analysis in some of the fermentations and was only occasionally picked up through culture-based isolation. Two new species of Acetobacter were found as well, namely, the species tentatively named “Acetobacter senegalensis” (A. tropicalis-like) and

  6. Dynamics and biodiversity of populations of lactic acid bacteria and acetic acid bacteria involved in spontaneous heap fermentation of cocoa beans in Ghana.

    Science.gov (United States)

    Camu, Nicholas; De Winter, Tom; Verbrugghe, Kristof; Cleenwerck, Ilse; Vandamme, Peter; Takrama, Jemmy S; Vancanneyt, Marc; De Vuyst, Luc

    2007-03-01

    The Ghanaian cocoa bean heap fermentation process was studied through a multiphasic approach, encompassing both microbiological and metabolite target analyses. A culture-dependent (plating and incubation, followed by repetitive-sequence-based PCR analyses of picked-up colonies) and culture-independent (denaturing gradient gel electrophoresis [DGGE] of 16S rRNA gene amplicons, PCR-DGGE) approach revealed a limited biodiversity and targeted population dynamics of both lactic acid bacteria (LAB) and acetic acid bacteria (AAB) during fermentation. Four main clusters were identified among the LAB isolated: Lactobacillus plantarum, Lactobacillus fermentum, Leuconostoc pseudomesenteroides, and Enterococcus casseliflavus. Other taxa encompassed, for instance, Weissella. Only four clusters were found among the AAB identified: Acetobacter pasteurianus, Acetobacter syzygii-like bacteria, and two small clusters of Acetobacter tropicalis-like bacteria. Particular strains of L. plantarum, L. fermentum, and A. pasteurianus, originating from the environment, were well adapted to the environmental conditions prevailing during Ghanaian cocoa bean heap fermentation and apparently played a significant role in the cocoa bean fermentation process. Yeasts produced ethanol from sugars, and LAB produced lactic acid, acetic acid, ethanol, and mannitol from sugars and/or citrate. Whereas L. plantarum strains were abundant in the beginning of the fermentation, L. fermentum strains converted fructose into mannitol upon prolonged fermentation. A. pasteurianus grew on ethanol, mannitol, and lactate and converted ethanol into acetic acid. A newly proposed Weissella sp., referred to as "Weissella ghanaensis," was detected through PCR-DGGE analysis in some of the fermentations and was only occasionally picked up through culture-based isolation. Two new species of Acetobacter were found as well, namely, the species tentatively named "Acetobacter senegalensis" (A. tropicalis-like) and "Acetobacter

  7. An in vitro study on the effect of free amino acids alone or in combination with nisin on biofilms as well as on planktonic bacteria of Streptococcus mutans.

    Directory of Open Access Journals (Sweden)

    Zhongchun Tong

    Full Text Available Free D-amino acids (D-AAs are one of the most striking features of the peptidoglycan composition in bacteria and play a key role in regulating and disassembling bacterial biofilms. Previous studies have indicated that the antimicrobial peptide nisin can inhibit the growth of the cariogenic bacteria Streptococcus mutans. The present study investigated the effect of free amino acids either alone or in combination with nisin on biofilm and on planktonic S. mutans bacteria. The results of the MIC and MBC analyses showed that D-cysteine (Cys, D- or L-aspartic acid (Asp, and D- or L-glutamic acid (Glu significantly improve the antibacterial activity of nisin against S. mutans and that the mixture of D-Cys, D-Asp, and D-Glu (3D-AAs and the mixture of L-Cys, L-Asp, and L-Glu (3L-AAs at a concentration of 40 mM can prevent S. mutans growth. Crystal violet staining showed that the D- or L-enantiomers of Cys, Asp, and Glu at a concentration of 40 mM can inhibit the formation of S. mutans biofilms, and their mixture generated a stronger inhibition than the components alone. Furthermore, the mixture of the three D-AAs or L-AAs may improve the antibacterial activity of nisin against S. mutans biofilms. This study underscores the potential of free amino acids for the enhancement of the antibacterial activity of nisin and the inhibition of the cariogenic bacteria S. mutans and biofilms.

  8. Effect of fatty acids on arenavirus replication: inhibition of virus production by lauric acid.

    Science.gov (United States)

    Bartolotta, S; García, C C; Candurra, N A; Damonte, E B

    2001-01-01

    To study the functional involvement of cellular membrane properties on arenavirus infection, saturated fatty acids of variable chain length (C10-C18) were evaluated for their inhibitory activity against the multiplication of Junin virus (JUNV). The most active inhibitor was lauric acid (C12), which reduced virus yields of several attenuated and pathogenic strains of JUNV in a dose dependent manner, without affecting cell viability. Fatty acids with shorter or longer chain length had a reduced or negligible anti-JUNV activity. Lauric acid did not inactivate virion infectivity neither interacted with the cell to induce a state refractory to virus infection. From mechanistic studies, it can be concluded that lauric acid inhibited a late maturation stage in the replicative cycle of JUNV. Viral protein synthesis was not affected by the compound, but the expression of glycoproteins in the plasma membrane was diminished. A direct correlation between the inhibition of JUNV production and the stimulation of triacylglycerol cell content was demonstrated, and both lauric-acid induced effects were dependent on the continued presence of the fatty acid. Thus, the decreased insertion of viral glycoproteins into the plasma membrane, apparently due to the increased incorporation of triacylglycerols, seems to cause an inhibition of JUNV maturation and release.

  9. Combination of aspartic acid and glutamic acid inhibits tumor cell proliferation.

    Science.gov (United States)

    Yamaguchi, Yoshie; Yamamoto, Katsunori; Sato, Yoshinori; Inoue, Shinjiro; Morinaga, Tetsuo; Hirano, Eiichi

    2016-01-01

    Placental extract contains several biologically active compounds, and pharmacological induction of placental extract has therapeutic effects, such as improving liver function in patients with hepatitis or cirrhosis. Here, we searched for novel molecules with an anti-tumor activity in placental extracts. Active molecules were separated by chromatographic analysis, and their antiproliferative activities were determined by a colorimetric assay. We identified aspartic acid and glutamic acid to possess the antiproliferative activity against human hepatoma cells. Furthermore, we showed that the combination of aspartic acid and glutamic acid exhibited enhanced antiproliferative activity, and inhibited Akt phosphorylation. We also examined in vivo tumor inhibition activity using the rabbit VX2 liver tumor model. The treatment mixture (emulsion of the amino acids with Lipiodol) administered by hepatic artery injection inhibited tumor cell growth of the rabbit VX2 liver. These results suggest that the combination of aspartic acid and glutamic acid may be useful for induction of tumor cell death, and has the potential for clinical use as a cancer therapeutic agent.

  10. Production and structural characterization of exopolysaccharides from newly isolated probiotic lactic acid bacteria.

    Science.gov (United States)

    Abid, Yousra; Casillo, Angela; Gharsallah, Houda; Joulak, Ichrak; Lanzetta, Rosa; Corsaro, Maria Michela; Attia, Hamadi; Azabou, Samia

    2018-03-01

    In this work, four exopolysaccharide-producing lactic acid bacteria (LAB) strains, newly isolated from Tunisian spontaneously fermented foods and beverages, namely bovine and turkey meat sausages (BMS and TMS), date palm sap (DPS) and cow milk (CM), were identified as Leuconostoc citreum-BMS, Leuconostoc mesenteroides-TMS, Pediococcus pentosaceus-DPS and Leuconostoc pseudomesenteroides-CM, respectively. The isolated strains showed the ability to withstand simulated human gastrointestinal (GI) tract conditions (low pH, lysozyme, bile salts, pepsin and pancreatin) and showed high surface hydrophobicity (79-90%), besides their ability to act against Escherichia coli and Listeria monocytogenes and to produce exopolysaccharides (EPS). Therefore, these isolates can be served as potential probiotics. The produced EPS were growth-associated suggesting that they are primary metabolites. The molecular weights were higher than 10 6 Da using HPLC-SEC. 2D-NMR results indicated that all the samples were mixtures of dextran and levan, except for EPS-CM which was a levan-type EPS. Furthermore, the EPS samples showed an abitlity to inhibit and to disrupt pathogenic biofilms and showed high thermostability studied via differential scanning calorimetry (DSC) with melting points higher than 224°C making them promising to be used in thermal processed foods. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. The Use of Lactic Acid Bacteria as a Probiotic in Swine Diets

    Directory of Open Access Journals (Sweden)

    Fengjuan Yang

    2015-01-01

    Full Text Available As the resistance of pathogens to antibiotics and the possibility of antibiotic residues in animal products attract increasing attention, the interest in the use of alternatives to in-feed antibiotics has been growing. Recent research with Lactic acid bacteria (LAB in pigs suggests that LAB provide a potential alternative to antibiotic strategies. LAB include Lactobacillus species, Bifidobacterium spp, Bacillus spp, and some other microbes. LAB can adjust the intestinal environment, inhibit or kill pathogens in the gastrointestinal tract and improve the microbial balance in the intestine, as well as regulate intestinal mucosal immunity and maintain intestinal barrier function, thereby benefiting the health of pigs. The related mechanisms for these effects of LAB may include producing microbicidal substances with effects against gastrointestinal pathogens and other harmful microbes, competing with pathogens for binding sites on the intestinal epithelial cell surface and mucin as well as stimulating the immune system. In this review, the characteristics of LAB and their probiotic effects in newborn piglets, weaned piglets, growing pigs and sows are documented.

  12. Cereal fungal infection, mycotoxins, and lactic acid bacteria mediated bioprotection: from crop farming to cereal products.

    Science.gov (United States)

    Oliveira, Pedro M; Zannini, Emanuele; Arendt, Elke K

    2014-02-01

    Lactic acid bacteria (LAB) metabolites are a reliable alternative for reducing fungal infections pre-/post-harvest with additional advantages for cereal-base products which convene the food market's trend. Grain industrial use is in expansion owing to its applicability in generating functional food. The food market is directed towards functional natural food with clear health benefits for the consumer in detriment to chemical additives. The food market chain is becoming broader and more complex, which presents an ever-growing fungal threat. Toxigenic and spoilage fungi are responsible for numerous diseases and economic losses. Cereal infections may occur in the field or post-processing, along the food chain. Consequently, the investigation of LAB metabolites with antifungal activity has gained prominence in the scientific research community. LAB bioprotection retards the development of fungal diseases in the field and inhibit pathogens and spoilage fungi in food products. In addition to the health safety improvement, LAB metabolites also enhance shelf-life, organoleptic and texture qualities of cereal-base foods. This review presents an overview of the fungal impact through the cereal food chain leading to investigation on LAB antifungal compounds. Applicability of LAB in plant protection and cereal industry is discussed. Specific case studies include Fusarium head blight, malting and baking. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Lactic Acid Bacteria and Their Bacteriocins: Classification, Biosynthesis and Applications against Uropathogens: A Mini-Review

    Directory of Open Access Journals (Sweden)

    Mduduzi Paul Mokoena

    2017-07-01

    Full Text Available Several lactic acid bacteria (LAB isolates from the Lactobacillus genera have been applied in food preservation, partly due to their antimicrobial properties. Their application in the control of human pathogens holds promise provided appropriate strains are scientifically chosen and a suitable mode of delivery is utilized. Urinary tract infection (UTI is a global problem, affecting mainly diabetic patients and women. Many uropathogens are developing resistance to commonly used antibiotics. There is a need for more research on the ability of LAB to inhibit uropathogens, with a view to apply them in clinical settings, while adhering to strict selection guidelines in the choice of candidate LAB. While several studies have indicated the ability of LAB to elicit inhibitory activities against uropathogens in vitro, more in vivo and clinical trials are essential to validate the efficacy of LAB in the treatment and prevention of UTI. The emerging applications of LAB such as in adjuvant therapy, oral vaccine development, and as purveyors of bioprotective agents, are relevant in infection prevention and amelioration. Therefore, this review explores the potential of LAB isolates and their bacteriocins to control uropathogens, with a view to limit clinical use of antibiotics.

  14. Anti-Listeria activity of lactic acid bacteria in two traditional Sicilian cheeses

    Directory of Open Access Journals (Sweden)

    Maria Luisa Scatassa

    2017-01-01

    Full Text Available Listeria monocytogenes is a pathogen frequently found in dairy products, and its growth is difficult to control. Bacteriocinlike inhibitory substances (BLIS, produced by lactic acid bacteria (LAB, having proven in vitro anti-Listeria activity, could provide an innovative approach to control L. monocytogenes; however, this application needs to be evaluated in vivo. In this study, twenty LAB strains isolated from different Sicilian dairy environments were tested for control of growth of L. monocytogenes in three different experimental trials. First, raw and UHT milk were inoculated with LAB strains alone, and LAB strains mixed with L. monocytogenes. Second, mini-cheeses containing LAB and/or L. monocytogenes were produced. Third, two traditional Sicilian cheeses inoculated with a multi-strain LAB mixture combined with L. monocytogenes were produced. The addition of BLIS produced by LAB to milk and in mini-cheese production was unable to inhibit the growth of L. monocytogenes. However, an anti-Listeria effect was observed in the Pecorino Siciliano cheeses, where, after 15 days of ripening, the cheeses with added LAB had fewer L. monocytogenes compared to the control cheeses with no added LAB, while in the Vastedda della valle del Belìce cheeses, the multi-strain LAB mixture completely prevented the growth of L. monocytogenes.

  15. Inhibition of histone deacetylase activity by valproic acid blocks adipogenesis.

    Science.gov (United States)

    Lagace, Diane C; Nachtigal, Mark W

    2004-04-30

    Adipogenesis is dependent on the sequential activation of transcription factors including the CCAAT/enhancer-binding proteins (C/EBP), peroxisome proliferator-activated receptor gamma (PPARgamma), and steroid regulatory element-binding protein (SREBP). We show that the mood stabilizing drug valproic acid (VPA; 0.5-2 mm) inhibits mouse 3T3 L1 and human preadipocyte differentiation, likely through its histone deacetylase (HDAC) inhibitory properties. The HDAC inhibitor trichostatin A (TSA) also inhibited adipogenesis, whereas the VPA analog valpromide, which does not possess HDAC inhibitory effects, did not prevent adipogenesis. Acute or chronic VPA treatment inhibited differentiation yet did not affect mitotic clonal expansion. VPA (1 mm) inhibited PPARgamma induced differentiation but does not activate a PPARgamma reporter gene, suggesting that it is not a PPARgamma ligand. VPA or TSA treatment reduced mRNA and protein levels of PPARgamma and SREBP1a. TSA reduced C/EBPalpha mRNA and protein levels, whereas VPA only produced a decrease in C/EBPalpha protein expression. Overall our results highlight a role for HDAC activity in adipogenesis that can be blocked by treatment with VPA.

  16. Glucose and D-Allulose contained medium to support the growth of lactic acid bacteria

    Science.gov (United States)

    Al-Baarri, A. N.; Legowo, A. M.; Pramono, Y. B.; Sari, D. I.; Pangestika, W.

    2018-01-01

    Monosaccharide has been known as support agent for the growth of lactic acid bacteria. However the combination among monosaccharides for supporting the living of bacteria has not been understood well. This research was done for analyzing the combination glucose and D-allulose for the growth of Lactobacillus acidophilus and Streptococcus thermophillus. The NaCl medium containing glucose and D-allulose was used to analyse the growth of bacteria. The study showed that glucose and D-allulose have been detected as supportive agent to L. acidophilus and S. thermophillus specifically. As conclusion, glucose and D-allulose supported the growth of lactic acid bacteria equally. This finding might provide the beneficial information for industry to utilize D-allulose as well as glucose.

  17. Fighting Off Wound Pathogens in Horses with Honeybee Lactic Acid Bacteria.

    Science.gov (United States)

    Olofsson, Tobias C; Butler, Éile; Lindholm, Christina; Nilson, Bo; Michanek, Per; Vásquez, Alejandra

    2016-10-01

    In the global perspective of antibiotic resistance, it is urgent to find potent topical antibiotics for the use in human and animal infection. Healing of equine wounds, particularly in the limbs, is difficult due to hydrostatic factors and exposure to environmental contaminants, which can lead to heavy bio-burden/biofilm formation and sometimes to infection. Therefore, antibiotics are often prescribed. Recent studies have shown that honeybee-specific lactic acid bacteria (LAB), involved in honey production, and inhibit human wound pathogens. The aim of this pilot study was to investigate the effects on the healing of hard-to-heal equine wounds after treatment with these LAB symbionts viable in a heather honey formulation. For this, we included ten horses with wound duration of >1 year, investigated the wound microbiota, and treated wounds with the novel honeybee LAB formulation. We identified the microbiota using MALDI-TOF mass spectrometry and DNA sequencing. In addition, the antimicrobial properties of the honeybee LAB formulation were tested against all wound isolates in vitro. Our results indicate a diverse wound microbiota including fifty-three bacterial species that showed 90 % colonization by at least one species of Staphylococcus. Treatment with the formulation promoted wound healing in all cases already after the first application and the wounds were either completely healed (n = 3) in less than 20 days or healing was in progress. Furthermore, the honeybee LAB formulation inhibited all pathogens when tested in vitro. Consequently, this new treatment option presents as a powerful candidate for the topical treatment of hard-to-heal wounds in horses.

  18. Inhibition of Listeria monocytogenes by fatty acids and monoglycerides.

    Science.gov (United States)

    Wang, L L; Johnson, E A

    1992-01-01

    Fatty acids and monoglycerides were evaluated in brain heart infusion broth and in milk for antimicrobial activity against the Scott A strain of Listeria monocytogenes. C12:0, C18:3, and glyceryl monolaurate (monolaurin) had the strongest activity in brain heart infusion broth and were bactericidal at 10 to 20 micrograms/ml, whereas potassium (K)-conjugated linoleic acids and C18:2 were bactericidal at 50 to 200 micrograms/ml. C14:0, C16:0, C18:0, C18:1, glyceryl monomyristate, and glyceryl monopalmitate were not inhibitory at 200 micrograms/ml. The bactericidal activity in brain heart infusion broth was higher at pH 5 than at pH 6. In whole milk and skim milk, K-conjugated linoleic acid was bacteriostatic and prolonged the lag phase especially at 4 degrees C. Monolaurin inactivated L. monocytogenes in skim milk at 4 degrees C, but was less inhibitory at 23 degrees C. Monolaurin did not inhibit L. monocytogenes in whole milk because of the higher fat content. Other fatty acids tested were not effective in whole or skim milk. Our results suggest that K-conjugated linoleic acids or monolaurin could be used as an inhibitory agent against L. monocytogenes in dairy foods. Images PMID:1610184

  19. Curcumin improves alcoholic fatty liver by inhibiting fatty acid biosynthesis.

    Science.gov (United States)

    Guo, Chang; Ma, Jingfan; Zhong, Qionghong; Zhao, Mengyuan; Hu, Tianxing; Chen, Tong; Qiu, Longxin; Wen, Longping

    2017-08-01

    Alcoholic fatty liver is a threat to human health. It has been long known that abstinence from alcohol is the most effective therapy, other effective therapies are not available for the treatment in humans. Curcumin has a great potential for anti-oxidation and anti-inflammation, but the effect on metabolic reconstruction remains little known. Here we performed metabolomic analysis by gas chromatography/mass spectrometry and explored ethanol pathogenic insight as well as curcumin action pattern. We identified seventy-one metabolites in mouse liver. Carbohydrates and lipids were characteristic categories. Pathway analysis results revealed that ethanol-induced pathways including biosynthesis of unsaturated fatty acids, fatty acid biosynthesis and pentose and glucuronate interconversions were suppressed by curcumin. Additionally, ethanol enhanced galactose metabolism and pentose phosphate pathway. Glyoxylate and dicarboxylate metabolism and pyruvate metabolism were inhibited in mice fed ethanol diet plus curcumin. Stearic acid, oleic acid and linoleic acid were disease biomarkers and therapical biomarkers. These results reflect the landscape of hepatic metabolism regulation. Our findings illustrate ethanol pathological pathway and metabolic mechanism of curcumin therapy. Copyright © 2017. Published by Elsevier Inc.

  20. Isolation and characterization of isopimaric acid-degrading bacteria from a sequencing batch reactor.

    OpenAIRE

    Wilson, A E; Moore, E R; Mohn, W W

    1996-01-01

    We isolated two aerobic, gram-negative bacteria which grew on the diterpene resin acid isopimaric acid (IpA) as the sole carbon source and electron donor. The source of the isolates was a sequencing batch reactor treating a high-strength process stream from a paper mill. The isolates, IpA-1 and IpA-2, also grew on pimaric and dehydroabietic acids, and IpA-1 grew on abietic acid. Both strains used fatty acids, but neither strain used camphor, sitosterol, or betulin. Strain IpA-1 grew anaerobic...

  1. Hydroxycinnamic acids used as external acceptors of electrons: an energetic advantage for strictly heterofermentative lactic acid bacteria.

    Science.gov (United States)

    Filannino, Pasquale; Gobbetti, Marco; De Angelis, Maria; Di Cagno, Raffaella

    2014-12-01

    The metabolism of hydroxycinnamic acids by strictly heterofermentative lactic acid bacteria (19 strains) was investigated as a potential alternative energy route. Lactobacillus curvatus PE5 was the most tolerant to hydroxycinnamic acids, followed by strains of Weissella spp., Lactobacillus brevis, Lactobacillus fermentum, and Leuconostoc mesenteroides, for which the MIC values were the same. The highest sensitivity was found for Lactobacillus rossiae strains. During growth in MRS broth, lactic acid bacteria reduced caffeic, p-coumaric, and ferulic acids into dihydrocaffeic, phloretic, and dihydroferulic acids, respectively, or decarboxylated hydroxycinnamic acids into the corresponding vinyl derivatives and then reduced the latter compounds to ethyl compounds. Reductase activities mainly emerged, and the activities of selected strains were further investigated in chemically defined basal medium (CDM) under anaerobic conditions. The end products of carbon metabolism were quantified, as were the levels of intracellular ATP and the NAD(+)/NADH ratio. Electron and carbon balances and theoretical ATP/glucose yields were also estimated. When CDM was supplemented with hydroxycinnamic acids, the synthesis of ethanol decreased and the concentration of acetic acid increased. The levels of these metabolites reflected on the alcohol dehydrogenase and acetate kinase activities. Overall, some biochemical traits distinguished the common metabolism of strictly heterofermentative strains: main reductase activity toward hydroxycinnamic acids, a shift from alcohol dehydrogenase to acetate kinase activities, an increase in the NAD(+)/NADH ratio, and the accumulation of supplementary intracellular ATP. Taken together, the above-described metabolic responses suggest that strictly heterofermentative lactic acid bacteria mainly use hydroxycinnamic acids as external acceptors of electrons. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  2. Effect of Wheat Dietary Fiber Particle Size during Digestion In Vitro on Bile Acid, Faecal Bacteria and Short-Chain Fatty Acid Content.

    Science.gov (United States)

    Dziedzic, Krzysztof; Szwengiel, Artur; Górecka, Danuta; Gujska, Elżbieta; Kaczkowska, Joanna; Drożdżyńska, Agnieszka; Walkowiak, Jarosław

    2016-06-01

    The influence of bile acid concentration on the growth of Bifidobacterium spp. and Lactobacillus spp. bacteria was demonstrated. Exposing these bacteria to the environment containing bile acid salts, and very poor in nutrients, leads to the disappearance of these microorganisms due to the toxic effect of bile acids. A multidimensional analysis of data in the form of principal component analysis indicated that lactic acid bacteria bind bile acids and show antagonistic effect on E. coli spp. bacteria. The growth in E. coli spp. population was accompanied by a decline in the population of Bifidobacterium spp. and Lactobacillus spp. with a simultaneous reduction in the concentration of bile acids. This is direct proof of acid binding ability of the tested lactic acid bacteria with respect to cholic acid, lithocholic acid and deoxycholic acid. This research demonstrated that the degree of fineness of wheat dietary fibre does not affect the sorption of bile acids and growth of some bacteria species; however, it has an impact on the profile of synthesized short-chained fatty acids. During the digestion of a very fine wheat fibre fraction (WF 90), an increase in the concentration of propionic and butyric acids, as compared with the wheat fiber fraction of larger particles - WF 500, was observed. Our study suggested that wheat fibre did not affect faecal bacteria growth, however, we observed binding of bile acids by Bifidobacterium spp. and Lactobacillus spp.

  3. Identification of 2-hydroxyisocaproic acid production in lactic acid bacteria and evaluation of microbial dynamics during kimchi ripening.

    Science.gov (United States)

    Park, Boyeon; Hwang, Hyelyeon; Chang, Ji Yoon; Hong, Sung Wook; Lee, Se Hee; Jung, Min Young; Sohn, Sung-Oh; Park, Hae Woong; Lee, Jong-Hee

    2017-09-07

    Lactic acid bacteria produce diverse functional metabolites in fermented foods. However, little is known regarding the metabolites and the fermentation process in kimchi. In this study, the culture broth from Leuconostoc lactis, a lactic acid bacterium isolated from kimchi, was analysed by liquid chromatography-tandem mass spectrometry and identified by the MS-DIAL program. The MassBank database was used to analyse the metabolites produced during fermentation. A mass spectrum corresponding to 2-hydroxyisocaproic acid (HICA) was validated based on a collision-induced dissociation (CID) fragmentation pattern with an identified m/z value of 131.07. HICA production by lactic acid bacteria was monitored and showed a positive correlation with hydroxyisocaproate dehydrogenases (HicDs), which play a key role in the production of HICA from leucine and ketoisocaproic acid. Interestingly, the HICA contents of kimchi varied with Leuconostoc and Lactobacillus content during the early stage of fermentation, and the addition of lactic acid bacteria enhanced the HICA content of kimchi. Our results suggest that HICA production in kimchi is dependent on the lactic acid bacterial composition.

  4. Conjugated linoleic acid content and organoleptic attributes of fermented milk products produced with probiotic bacteria.

    Science.gov (United States)

    Xu, Sa; Boylston, Terri D; Glatz, Bonita A

    2005-11-16

    The effect of probiotic bacteria on the formation of conjugated linoleic acid (CLA), microbial growth, and organoleptic attributes (acidity, texture, and flavor) of fermented milk products was determined. Four probiotic bacteria, Lactobacillus rhamnosus, Propionibacterium freudenreichii subsp. shermanii 56, P. freudenreichii subsp. shermanii 51, and P. freudenreichii subsp. freudenreichii 23, were evaluated individually or in coculture with traditional yogurt cultures (Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus). The lipid source was hydrolyzed soy oil. L. rhamnosus, in coculture with yogurt culture, resulted in the highest content of CLA. Growth and CLA formation of propionibacteria were enhanced in the presence of yogurt cultures. Texture and flavor attributes of fermented milks produced with propionibacteria were significantly different than the fermented milks processed with yogurt cultures. The fermented milks processed with probiotic bacteria in coculture with yogurt cultures demonstrated similar acidity, texture, and flavor as the fermented milk produced with yogurt cultures.

  5. Role in Cheese Flavour Formation of Heterofermentative Lactic Acid Bacteria from Mesophilic Starter Cultures

    DEFF Research Database (Denmark)

    Pedersen, Thomas Bæk

    Undefined mesophilic cheese starters are complex ecosystems that contain both homofermentative and heterofermentative lactic acid bacteria, with the Lactococcus genera representing the former and Lceuonostoc and sometimes Lactobacillus the latter. These starters originate from old butter starters...... with plant isolates, the ability to ferment citrate and lacked several genes involved in the fermentation of complex carbohydrates. The presented research in this thesis has gained insight in to the role of heterofermentative lactic acid bacteria in cheese flavour formation. The traditional DL......-starters contained numerous of strains of heterofermentative Le. mesenteroides, whereas Le. pseudomesenteroides and  only were found in some starters. The potential of heterofermentative lactic acid bacteria to effect the flavour formation in cheese seems to be dependent on how well they grow and establish...

  6. Cancer Preventive Potential of Kimchi Lactic Acid Bacteria (Weissella cibaria, Lactobacillus plantarum).

    Science.gov (United States)

    Kwak, Shin-Hye; Cho, Young-Mi; Noh, Geon-Min; Om, Ae-Son

    2014-12-01

    The number of death due to cancer has been increasing in Korea. Chemotherapy is known to cause side effects because it damages not only cancerous cells but healthy cells. Recently, attention has focused on food-derived chemopreventive and anti-tumor agents or formulations with fewer side effects. Kimchi, most popular and widely consumed in Korea, contains high levels of lactic acid bacteria and has been shown to possess chemopreventive effects. This review focuses on Weissella cibaria and Lactobacillus plantarum, the representatives of kimchi lactic acid bacteria, in terms of their abilities to prevent cancer. Further studies are needed to understand the mechanisms by which lactic acid bacteria in kimchi prevent carcinogenic processes and improve immune functions.

  7. THE SEARCH AND PROPERTIES OF LACTIC ACID BACTERIA PERSPECTIVE FOR BIOTECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Naumenko О. V.

    2014-10-01

    Full Text Available Search of biologically active Lactobacillus strains prospective for functional milk food production was the aim of the research. The study involved the lactic acid bacteria isolated from biological material of healthy humen and non- dairy lactic products. Using modern methodological approaches, the strains of lactic acid bacteria such as Lactobacillus casei 302, Lactobacillus acidophilus 35 and Streptococcus thermophilus 21 having high level of biological activity were selected. High biological potential of selected cultures of lactic acid bacteria, which could provide stability for the technological process of production and essential characteristics of bacterial preparations and fermented their products, was set. In vitro the experiments demonstrated that selected strains had valuable production properties, namely the ability to reduce level of cholesterol and lactose during development in milk, were resistant to virulent bacteriophages and aggressive compounds of the gastrointestinal tract, and high adhesive and antagonistic activities as well.

  8. Phenotypic and genotypic characterization of lactic acid bacteria isolated from raw goat milk and effect of farming practices on the dominant species of lactic acid bacteria.

    Science.gov (United States)

    Tormo, Hélène; Ali Haimoud Lekhal, Djamila; Roques, C

    2015-10-01

    Lactic acid bacteria, in particular Lactococcus lactis, play a decisive role in the cheese making process and more particularly in lactic cheeses which are primarily produced on goat dairy farms. The objective of this study was therefore to identify the main lactic acid bacteria found in raw goats' milk from three different regions in France and evaluate if certain farming practices have an effect on the distribution of species of lactic acid bacteria in the various milk samples. Identification at genus or species level was carried out using phenotypic tests and genotypic methods including repetitive element REP-PCR, species-specific PCR and 16S rRNA gene sequencing. The distribution of the main bacterial species in the milk samples varied depending on farms and their characteristics. Out of the 146 strains identified, L. lactis was the dominant species (60% of strains), followed by Enterococcus (38%) of which Enterococcus faecalis and Enterococcus faecium. Within the species L. lactis, L. lactis subsp lactis was detected more frequently than L. lactis subsp cremoris (74% vs. 26%). The predominance of L. lactis subsp cremoris was linked to geographical area studied. It appears that the animals' environment plays a role in the balance between the dominance of L. lactis and enterococci in raw goats' milk. The separation between the milking parlor and the goat shed (vs no separation) and only straw in the bedding (vs straw and hay) seems to promote L. lactis in the milk (vs enterococci). Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Screening for proteolytically active lactic acid bacteria and bioactivity of peptide hydrolysates obtained with selected strains.

    Science.gov (United States)

    Kliche, T; Li, B; Bockelmann, W; Habermann, D; Klempt, M; de Vrese, M; Wutkowski, A; Clawin-Raedecker, I; Heller, K J

    2017-10-01

    In a screening for proteolytically active lactic acid bacteria, three strains, Lactobacillus delbrueckii ssp. lactis 92202, Lactobacillus helveticus 92201, and Lactobacillus delbrueckii ssp. bulgaricus 92059, showed the highest activities following growth in milk. All three strains degraded α- and β-casein, but did not hydrolyse κ-casein. HPLC analysis of skim milk fermentation revealed increasing amounts of peptides after 5 and 10 h with Lb. d. ssp. bulgaricus 92059. Hydrolysates obtained with Lb. d. ssp. lactis 92202 and Lb. d. ssp. bulgaricus 92059 revealed the highest angiotensin-converting enzyme-inhibitory effect. The effect was dose dependent. Almost no effect (<10%) was seen for Lb. helveticus 92201. For Lb. d. ssp. bulgaricus 92059, maximal inhibition of approx. 65% was reached after 25 h of fermentation. In an in vitro assay measuring potential immunomodulation, hydrolysates of the three strains yielded anti-inflammatory activities in the presence of TNF-α. However, the effects were more pronounced at lower hydrolysate concentrations. In the absence of TNF-α, slight pro-inflammatory effects were observed. The hydrolysate of Lb. d. ssp. bulgaricus 92059, when purified by means of solid-phase extraction, exhibited pro-inflammatory activity. Sour whey containing Lb. d. ssp. bulgaricus 92059 cells showed pro-inflammatory activity while cell-free sour whey was clearly anti-inflammatory. In the purified hydrolysate, 20 different α- and β-casein (CN)-derived peptides could be identified by LC-MS. Most peptides originated from the central and C-terminal regions of β-casein. Peptide length was between 9 (β-CN(f 59-67)) and 22 amino acids (β-CN(f 117-138)).

  10. Selection of potential probiotic lactic acid bacteria from fermented olives by in vitro tests.

    Science.gov (United States)

    Argyri, Anthoula A; Zoumpopoulou, Georgia; Karatzas, Kimon-Andreas G; Tsakalidou, Effie; Nychas, George-John E; Panagou, Efstathios Z; Tassou, Chrysoula C

    2013-04-01

    The present study aims to evaluate the probiotic potential of lactic acid bacteria (LAB) isolated from naturally fermented olives and select candidates to be used as probiotic starters for the improvement of the traditional fermentation process and the production of newly added value functional foods. Seventy one (71) lactic acid bacterial strains (17 Leuconostoc mesenteroides, 1 Ln. pseudomesenteroides, 13 Lactobacillus plantarum, 37 Lb. pentosus, 1 Lb. paraplantarum, and 2 Lb. paracasei subsp. paracasei) isolated from table olives were screened for their probiotic potential. Lb. rhamnosus GG and Lb. casei Shirota were used as reference strains. The in vitro tests included survival in simulated gastrointestinal tract conditions, antimicrobial activity (against Listeria monocytogenes, Salmonella Enteritidis, Escherichia coli O157:H7), Caco-2 surface adhesion, resistance to 9 antibiotics and haemolytic activity. Three (3) Lb. pentosus, 4 Lb. plantarum and 2 Lb. paracasei subsp. paracasei strains demonstrated the highest final population (>8 log cfu/ml) after 3 h of exposure at low pH. The majority of the tested strains were resistant to bile salts even after 4 h of exposure, while 5 Lb. plantarum and 7 Lb. pentosus strains exhibited partial bile salt hydrolase activity. None of the strains inhibited the growth of the pathogens tested. Variable efficiency to adhere to Caco-2 cells was observed. This was the same regarding strains' susceptibility towards different antibiotics. None of the strains exhibited β-haemolytic activity. As a whole, 4 strains of Lb. pentosus, 3 strains of Lb. plantarum and 2 strains of Lb. paracasei subsp. paracasei were found to possess desirable in vitro probiotic properties similar to or even better than the reference probiotic strains Lb. casei Shirota and Lb. rhamnosus GG. These strains are good candidates for further investigation both with in vivo studies to elucidate their potential health benefits and in olive fermentation processes

  11. 10-oxo-12(Z)-octadecenoic acid, a linoleic acid metabolite produced by gut lactic acid bacteria, potently activates PPARγ and stimulates adipogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Goto, Tsuyoshi, E-mail: tgoto@kais.kyoto-u.ac.jp [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011 (Japan); Research Unit for Physiological Chemistry, The Center for the Promotion of Interdisciplinary Education and Research, Kyoto University (Japan); Kim, Young-Il; Furuzono, Tomoya [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011 (Japan); Takahashi, Nobuyuki [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011 (Japan); Research Unit for Physiological Chemistry, The Center for the Promotion of Interdisciplinary Education and Research, Kyoto University (Japan); Yamakuni, Kanae; Yang, Ha-Eun; Li, Yongjia [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011 (Japan); Ohue, Ryuji [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011 (Japan); Research Unit for Physiological Chemistry, The Center for the Promotion of Interdisciplinary Education and Research, Kyoto University (Japan); Nomura, Wataru [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011 (Japan); Sugawara, Tatsuya [Laboratory of Marine Bioproducts Technology, Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502 (Japan); Yu, Rina [Department of Food Science and Nutrition, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Kitamura, Nahoko [Laboratory of Fermentation Physiology and Applied Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502 (Japan); and others

    2015-04-17

    Our previous study has shown that gut lactic acid bacteria generate various kinds of fatty acids from polyunsaturated fatty acids such as linoleic acid (LA). In this study, we investigated the effects of LA and LA-derived fatty acids on the activation of peroxisome proliferator-activated receptors (PPARs) which regulate whole-body energy metabolism. None of the fatty acids activated PPARδ, whereas almost all activated PPARα in luciferase assays. Two fatty acids potently activated PPARγ, a master regulator of adipocyte differentiation, with 10-oxo-12(Z)-octadecenoic acid (KetoA) having the most potency. In 3T3-L1 cells, KetoA induced adipocyte differentiation via the activation of PPARγ, and increased adiponectin production and insulin-stimulated glucose uptake. These findings suggest that fatty acids, including KetoA, generated in gut by lactic acid bacteria may be involved in the regulation of host energy metabolism. - Highlights: • Most LA-derived fatty acids from gut lactic acid bacteria potently activated PPARα. • Among tested fatty acids, KetoA and KetoC significantly activated PPARγ. • KetoA induced adipocyte differentiation via the activation of PPARγ. • KetoA enhanced adiponectin production and glucose uptake during adipogenesis.

  12. Spontaneous organic cocoa bean box fermentations in Brazil are characterized by a restricted species diversity of lactic acid bacteria and acetic acid bacteria.

    Science.gov (United States)

    Papalexandratou, Zoi; Vrancken, Gino; De Bruyne, Katrien; Vandamme, Peter; De Vuyst, Luc

    2011-10-01

    Spontaneous organic cocoa bean box fermentations were carried out on two different farms in Brazil. Physical parameters, microbial growth, bacterial species diversity [mainly lactic acid bacteria (LAB) and acetic acid bacteria (AAB)], and metabolite kinetics were monitored, and chocolates were produced from the fermented dry cocoa beans. The main end-products of the catabolism of the pulp substrates (glucose, fructose, and citric acid) by yeasts, LAB, and AAB were ethanol, lactic acid, mannitol, and/or acetic acid. Lactobacillus fermentum and Acetobacter pasteurianus were the predominating bacterial species of the fermentations as revealed through (GTG)(5)-PCR fingerprinting of isolates and PCR-DGGE of 16S rRNA gene PCR amplicons of DNA directly extracted from fermentation samples. Fructobacillus pseudoficulneus, Lactobacillus plantarum, and Acetobacter senegalensis were among the prevailing species during the initial phase of the fermentations. Also, three novel LAB species were found. This study emphasized the possible participation of Enterobacteriaceae in the cocoa bean fermentation process. Tatumella ptyseos and Tatumella citrea were the prevailing enterobacterial species in the beginning of the fermentations as revealed by 16S rRNA gene-PCR-DGGE. Finally, it turned out that control over a restricted bacterial species diversity during fermentation through an ideal post-harvest handling of the cocoa beans will allow the production of high-quality cocoa and chocolates produced thereof, independent of the fermentation method or farm. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Bile Salt and Acid Tolerant of Lactic Acid Bacteria Isolated from Proventriculus of Broiler Chicken

    Directory of Open Access Journals (Sweden)

    E. Damayanti

    2014-08-01

    Full Text Available The aim of this research was to obtain the lactic acid bacteria (LAB as probiotic candidates which have resistance to bile salt and acid condition. LAB was obtained using isolation method from proventriculus of broiler chicken. Selective MRS media with 0.2% CaCO3 addition were used for LAB isolation using pour plate sampling method under anaerobic condition. The result showed that four selected isolates had morphological and biochemical characteristics as LAB. The selected LAB was characterized as follow: antibacterial activities, antibiotic sensitivity, resistance on bile salt, gastric juice and acid condition, and biochemical identification. Antibacterial activities assay of cell free supernatant was confirmed using disc paper diffusion method which was arranged on factorial design and each treatment consisted of three replications. The cell free supernatant of LAB isolates had antibacterial activities against Escherichia coli, Pseudomonas aerugenosa, and Salmonella pullorum. Molecular identification procedure using 16S rRNA sequence analysis showed that R01 and R02 as Pediococcus acidilactici. The viability of the two isolates were tested by acid pH (pH 1, 2, and 3, gastric juice pH 2, and bile salt condition for digestives tract simulation. The result showed that R01 and R02 had a high viability percentages at pH 1, 2, and 3 (95.45%, 99.49%, 104.01%, and 67.17%, 120.74%, 103.4%, respectively and at bile salt simulation for 1-2 hours (100.35%-102.71% and 100.02%-102.65%, respectively, but at gastric juice simulation for 1-2 hours, the P. acidilactici R01 had higher viability than P. acidilactici R02 (59.69%-76.53% versus 43.57%-40.69%, respectively. In the antibiotic sensitivity test for three antibiotics (i.e. erythromicin 15 µg, penicillin G 10 µg, and streptomycin 10 µg, the P. acidilactici R02 showed resistance to Streptomycin and Penicillin. It is concluded that P. acidilactici R01 and P. acidilactici R02 isolated from proventriculus

  14. Modulation of folate production in lactic acid bacteria

    NARCIS (Netherlands)

    Wegkamp, H.B.A.

    2008-01-01

    Food fortification has proven to be very useful in reducing health problems associated with mal-intake of essential nutrients, such as the B-vitamin folate. Folate is used as one-carbon donor/acceptor in several biochemical processes like synthesis of DNA, RNA and some amino acids. Sufficient intake

  15. Time related total lactic acid bacteria population diversity and ...

    African Journals Online (AJOL)

    The total lactic acid bacterial community involved in the spontaneous fermentation of malted cowpea fortified cereal weaning food was investigated by phenotypically and cultivation independent method. A total of 74 out of the isolated 178 strains were Lactobacillus plantarum, 32 were Pediococcus acidilactici and over 60% ...

  16. Evaluation of the probiotic potential of lactic acid bacteria isolated ...

    African Journals Online (AJOL)

    The predominant species among the isolated strains were Lactobacillus (Lb.) acidophilus, Lb. plantarum, Enterococcus (E.) faecium, and E. faecalis. Probiotic properties such as bile resistance, acid tolerance, and adhesion to intestinal mucous were assessed. In vitro results obtained showed that five strains, Lb. plantarum ...

  17. Effect of lactic acid bacteria starter culture fermentation of cassava ...

    African Journals Online (AJOL)

    The effects of lactic acid fermentation of cassava on the chemical and sensory characteristic of fufu flour were investigated. Two strains of Lactobacillus plantarum were used as starter cultures for the fermentation of cassava to fufu for 96 h. The resultant wet fufu samples were dried at 65oC in a cabinet dryer for 48 h and ...

  18. Temperature-dependent inhibition of opportunistic Vibrio pathogens by native coral commensal bacteria.

    Science.gov (United States)

    Frydenborg, Beck R; Krediet, Cory J; Teplitski, Max; Ritchie, Kim B

    2014-02-01

    Bacteria living within the surface mucus layer of corals compete for nutrients and space. A number of stresses affect the outcome of this competition. The interactions between native microorganisms and opportunistic pathogens largely determine the coral holobiont's overall health and fitness. In this study, we tested the hypothesis that commensal bacteria isolated from the mucus layer of a healthy elkhorn coral, Acropora palmata, are capable of inhibition of opportunistic pathogens, Vibrio shiloi AK1 and Vibrio coralliilyticus. These vibrios are known to cause disease in corals and their virulence is temperature dependent. Elevated temperature (30 °C) increased the cell numbers of one commensal and both Vibrio pathogens in monocultures. We further tested the hypothesis that elevated temperature favors pathogenic organisms by simultaneously increasing the fitness of vibrios and decreasing the fitness of commensals by measuring growth of each species within a co-culture over the course of 1 week. In competition experiments between vibrios and commensals, the proportion of Vibrio spp. increased significantly under elevated temperature. We finished by investigating several temperature-dependent mechanisms that could influence co-culture differences via changes in competitive fitness. The ability of Vibrio spp. to utilize glycoproteins found in A. palmata mucus increased or remained stable when exposed to elevated temperature, while commensals' tended to decrease utilization. In both vibrios and commensals, protease activity increased at 30 °C, while chiA expression increased under elevated temperatures for Vibrio spp. These results provide insight into potential mechanisms through which elevated temperature may select for pathogenic bacterial dominance and lead to disease or a decrease in coral fitness.

  19. Iodine from bacterial iodide oxidization by Roseovarius spp. inhibits the growth of other bacteria.

    Science.gov (United States)

    Zhao, Dan; Lim, Choon-Ping; Miyanaga, Kazuhiko; Tanji, Yasunori

    2013-03-01

    Microbial activities in brine, seawater, or estuarine mud are involved in iodine cycle. To investigate the effects of the microbiologically induced iodine on other bacteria in the environment, a total of 13 bacteria that potentially participated in the iodide-oxidizing process were isolated from water or biofilm at a location containing 131 μg ml(-1) iodide. Three distinct strains were further identified as Roseovarius spp. based on 16 S rRNA gene sequences after being distinguished by restriction fragment length polymorphism analysis. Morphological characteristics of these three Roseovarius spp. varied considerably across and within strains. Iodine production increased with Roseovarius spp. growth when cultured in Marine Broth with 200 μg ml(-1) iodide (I(-)). When 10(6) CFU/ml Escherichia coli, Pseudomonas aeruginosa, and Bacillus pumilus were exposed to various concentrations of molecular iodine (I(2)), the minimum inhibitory concentrations (MICs) were 0.5, 1.0, and 1.0 μg ml(-1), respectively. However, fivefold increases in the MICs for Roseovarius spp. were obtained. In co-cultured Roseovarius sp. IOB-7 and E. coli in Marine Broth containing iodide (I(-)), the molecular iodine concentration was estimated to be 0.76 μg ml(-1) after 24 h and less than 50 % of E. coli was viable compared to that co-cultured without iodide. The growth inhibition of E. coli was also observed in co-cultures with the two other Roseovarius spp. strains when the molecular iodine concentration was assumed to be 0.52 μg ml(-1).

  20. Analyses of Dynamics in Dairy Products and Identification of Lactic Acid Bacteria Population by Molecular Methods

    Directory of Open Access Journals (Sweden)

    Aytül Sofu

    2017-01-01

    Full Text Available Lactic acid bacteria (LAB with different ecological niches are widely seen in fermented meat, vegetables, dairy products and cereals as well as in fermented beverages. Lactic acid bacteria are the most important group of bacteria in dairy industry due to their probiotic characteristics and fermentation agents as starter culture. In the taxonomy of the lactic acid bacteria; by means of rep-PCR, which is the analysis of repetitive sequences that are based on 16S ribosomal RNA (rRNA gene sequence, it is possible to conduct structural microbial community analyses such as Restriction Fragment Length Polymorphism (RFLP analysis of DNA fragments of different sizes cut with enzymes, Random Amplified Polymorphic DNA (RAPD polymorphic DNA amplified randomly at low temperatures and Amplified Fragment-Length Polymorphism (AFLP-PCR of cut genomic DNA. Besides, in the recent years, non-culture-based molecular methods such as Pulse Field Gel Electrophoresis (PFGE, Denaturing Gradient Gel Electrophoresis (DGGE, Thermal Gradient Gel Electrophoresis (TGGE, and Fluorescence In-situ Hybridization (FISH have replaced classical methods once used for the identification of LAB. Identification of lactic acid bacteria culture independent regardless of the method will be one of the most important methods used in the future pyrosequencing as a Next Generation Sequencing (NGS techniques. This paper reviews molecular-method based studies conducted on the identification of LAB species in dairy products.

  1. Bacteria immobilized electrospun polycaprolactone and polylactic acid fibrous webs for remediation of textile dyes in water.

    Science.gov (United States)

    Sarioglu, Omer Faruk; San Keskin, Nalan Oya; Celebioglu, Asli; Tekinay, Turgay; Uyar, Tamer

    2017-10-01

    In this study, preparation and application of novel biocomposite materials for textile dye removal which are produced by immobilization of specific bacteria onto electrospun nanofibrous webs are presented. A textile dye remediating bacterial isolate, Clavibacter michiganensis, was selected for bacterial immobilization, a commercial reactive textile dye, Setazol Blue BRF-X, was selected as the target contaminant, and electrospun polycaprolactone (PCL) and polylactic acid (PLA) nanofibrous polymeric webs were selected for bacterial integration. Bacterial adhesion onto nanofibrous webs was monitored by scanning electron microscopy (SEM) imaging and optical density (OD) measurements were performed for the detached bacteria. After achieving sufficient amounts of immobilized bacteria on electrospun nanofibrous webs, equivalent web samples were utilized for testing the dye removal capabilities. Both bacteria/PCL and bacteria/PLA webs have shown efficient remediation of Setazol Blue BRF-X dye within 48 h at each tested concentration (50, 100 and 200 mg/L), and their removal performances were very similar to the free-bacteria cells. The bacteria immobilized webs were then tested for five times of reuse at an initial dye concentration of 100 mg/L, and found as potentially reusable with higher bacterial immobilization and faster dye removal capacities at the end of the test. Overall, these findings suggest that electrospun nanofibrous webs are available platforms for bacterial integration and the bacteria immobilized webs can be used as starting inocula for use in remediation of textile dyes in wastewater systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Characterization of airag collected in Ulaanbaatar, Mongolia with emphasis on isolated lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Suk-Ho Choi

    2016-03-01

    Full Text Available Abstract Background Airag, alcoholic sour-tasting beverage, has been traditionally prepared by Mongolian nomads who naturally ferment fresh mares’ milk. Biochemical and microbiological compositions of airag samples collected in Ulaanbaatar, Mongolia and physiological characteristics of isolated lactic acid bacteria were investigated. Methods Protein composition and biochemical composition were determined using sodium dodecyl sulfate-gel electrophoresis and high performance liquid chromatography, respectively. Lactic acid bacteria were identified based on nucleotide sequence of 16S rRNA gene. Carbohydrate fermentation, acid survival, bile resistance and acid production in skim milk culture were determined. Results Equine whey proteins were present in airag samples more than caseins. The airag samples contained 0.10–3.36 % lactose, 1.44–2.33 % ethyl alcohol, 1.08–1.62 % lactic acid and 0.12–0.22 % acetic acid. Lactobacillus (L. helveticus were major lactic acid bacteria consisting of 9 isolates among total 18 isolates of lactic acid bacteria. L. helveticus survived strongly in PBS, pH 3.0 but did not grow in MRS broth containing 0.1 % oxgall. A couple of L. helveticus isolates lowered pH of skim milk culture to less than 4.0 and produced acid up to more than 1.0 %. Conclusion Highly variable biochemical compositions of the airag samples indicated inconsistent quality due to natural fermentation. Airag with low lactose content should be favorable for nutrition, considering that mares’ milk with high lactose content has strong laxative effect. The isolates of L. helveticus which produced acid actively in skim milk culture might have a major role in production of airag.

  3. Plasmids from Food Lactic Acid Bacteria: Diversity, Similarity, and New Developments

    Directory of Open Access Journals (Sweden)

    Yanhua Cui

    2015-06-01

    Full Text Available Plasmids are widely distributed in different sources of lactic acid bacteria (LAB as self-replicating extrachromosomal genetic materials, and have received considerable attention due to their close relationship with many important functions as well as some industrially relevant characteristics of the LAB species. They are interesting with regard to the development of food-grade cloning vectors. This review summarizes new developments in the area of lactic acid bacteria plasmids and aims to provide up to date information that can be used in related future research.

  4. Acetic Acid Bacteria and the Production and Quality of Wine Vinegar

    Directory of Open Access Journals (Sweden)

    Albert Mas

    2014-01-01

    Full Text Available The production of vinegar depends on an oxidation process that is mainly performed by acetic acid bacteria. Despite the different methods of vinegar production (more or less designated as either “fast” or “traditional”, the use of pure starter cultures remains far from being a reality. Uncontrolled mixed cultures are normally used, but this review proposes the use of controlled mixed cultures. The acetic acid bacteria species determine the quality of vinegar, although the final quality is a combined result of technological process, wood contact, and aging. This discussion centers on wine vinegar and evaluates the effects of these different processes on its chemical and sensory properties.

  5. Putrescine production from different amino acid precursors by lactic acid bacteria from wine and cider.

    Science.gov (United States)

    Costantini, Antonella; Pietroniro, Roberta; Doria, Francesca; Pessione, Enrica; Garcia-Moruno, Emilia

    2013-07-01

    The aim of this work was to study the production of biogenic amines and particularly putrescine in lactic acid bacteria (LAB) related to wine and cider. We applied an analytical protocol that involves the use of PCR and TLC techniques to determine the production of putrescine from different precursors. Moreover, we also studied the ability of the Lactobacillus and Pediococcus tested to produce histamine and tyramine. The results showed that the majority of the Lactobacillus brevis analyzed harbour both AgDI and tdc genes and are tyramine and putrescine producers. Conversely, among the other LAB tested, only one Lactobacillus hilgardii and one Pediococcus pentosaceus produced putrescine. The AgDI gene was also detected in two other LAB (Lactobacillus mali and Pediococcus parvulus), but no putrescine production was observed. Finally, hdc gene and histamine production were found in strains (L. hilgardii 5211, isolated from wine, and Lactobacillus casei 18, isolated from cider) that were not putrescine producers. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Antimicrobial activity of lactic acid bacteria isolated from bekasam against staphylococcus aureus ATCC 25923, escherichia coli ATCC 25922, and salmonella sp

    Science.gov (United States)

    Sari, Melia; Suryanto, Dwi; Yurnaliza

    2018-03-01

    Bekasam is an Indonesian fermented food made of fish. As a fermented food, this food may contain some beneficial bacteria like lactic acid bacteria (LAB), which usually have antimicrobial properties such as organic acid, hydrogen peroxide, and a bacteriocin. A study on antimicrobial activity of LAB isolated from bekasam against some pathogenic bacteria has been conducted. The purpose of this study was to know the ability of crude bacteriocin produced LAB of bekasam against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Salmonella sp. Bekasam sample was taken from South Sumatera. LAB isolation was done using de Man Rogosa and Sharpe agar. A bacterial colony with clear zone was selected and purified to get a single colony. The antagonistic assay of the LAB was conducted in Muller-Hinton agar Selected isolates with higher clearing zone were assayed for antibacterial effect of their crude bacteriocin of different culture incubation time of 6, 9, and 12 hours. The results showed that the crude extract bacteriocin of isolate MS2 of 9 hours culture incubation time inhibited more in Staphylococcus aureus ATCC 25923 with inhibition zone of 13.1 mm, whereas isolate MS9 of 9 hours culture incubation time inhibited more in Escherichia coli ATCC 25922 and Salmonella sp. with inhibition zone of 12.7 and 7.3 mm, respectively.

  7. Phenols in anaerobic digestion processes and inhibition of ammonia oxidising bacteria (AOB) in soil

    International Nuclear Information System (INIS)

    Leven, Lotta; Nyberg, Karin; Korkea-aho, Lena; Schnuerer, Anna

    2006-01-01

    This study focuses on the presence of phenols in digestate from seven Swedish large-scale anaerobic digestion processes and their impact on the activity of ammonia oxidising bacteria (AOB) in soil. In addition, the importance of feedstock composition and phenol degradation capacity for the occurrence of phenols in the digestate was investigated in the same processes. The results revealed that the content of phenols in the digestate was related to the inhibition of the activity of AOB in soil (EC 5 = 26 μg phenols g -1 d.w. soil). In addition, five pure phenols (phenol, o-, p-, m-cresol and 4-ethylphenol) inhibited the AOB to a similar extent (EC 5 = 43-110 μg g -1 d.w. soil). The phenol content in the digestate was mainly dependent on the composition of the feedstock, but also to some extent by the degradation capacity in the anaerobic digestion process. Swine manure in the feedstock resulted in digestate containing higher amounts of phenols than digestate from reactors with less or no swine manure in the feedstock. The degradation capacity of phenol and p-cresol was studied in diluted small-scale batch cultures and revealed that anaerobic digestion at mesophilic temperatures generally exhibited a higher degradation capacity compared to digestion at thermophilic temperature. Although phenol, p-cresol and 4-ethylphenol were quickly degraded in soil, the phenols added with the digestate constitute an environmental risk according to the guideline values for contaminated soils set by the Swedish Environmental Protection Agency. In conclusion, the management of anaerobic digestion processes is of decisive importance for the production of digestate with low amounts of phenols, and thereby little risks for negative effects of the phenols on the soil ecosystem

  8. Ring cleavage and degradative pathway of cyanuric acid in bacteria.

    Science.gov (United States)

    Cook, A M; Beilstein, P; Grossenbacher, H; Hütter, R

    1985-01-01

    The degradative pathway of cyanuric acid [1,3,5-triazine-2,4,6(1H,3H,5H)-trione] was examined in Pseudomonas sp. strain D. The bacterium grew with cyanuric acid, biuret, urea or NH4+ as sole source of nitrogen, and each substrate was entirely metabolized concomitantly with growth. Enzymes from strain D were separated by chromatography on DEAE-cellulose and three reactions were examined. Cyanuric acid (1 mol) was converted stoichiometrically into 1.0 mol of CO2 and 1.1 mol of biuret, which was conclusively identified. Biuret (1 mol) was converted stoichiometrically into 1.1 mol of NH4+, about 1 mol of CO2 and 1.0 mol of urea, which was conclusively identified. Urea (1 mol) was converted into 1.9 mol of NH4+ and 1.0 mol of CO2. The reactions proceeded under aerobic or anoxic conditions and were presumed to be hydrolytic. Data indicate that the same pathway occurred in another pseudomonad and a strain of Klebsiella pneumoniae. PMID:3904735

  9. Unusal pattern of product inhibition: batch acetic acid fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Bar, R.; Gainer, J.L.; Kirwan, D.J.

    1987-04-20

    The limited tolerance of microorganisms to their metabolic products results in inhibited growth and product formation. The relationship between the specific growth rate, micro, and the concentration of an inhibitory product has been described by a number of mathematical models. In most cases, micro was found to be inversely proportional to the product concentration and invariably the rate of substrate utilization followed the same pattern. In this communication, the authors report a rather unusual case in which the formation rate of a product, acetic acid, increased with a decreasing growth rate of the microorganism, Acetobacter aceti. Apparently, a similar behavior was mentioned in a review report with respect to Clostridium thermocellum in a batch culture but was not published in the freely circulating literature. The fermentation of ethanol to acetic acid, C/sub 2/H/sub 5/OH + O/sub 2/ = CH/sub 3/COOH + H/sub 2/O is clearly one of the oldest known fermentations. Because of its association with the commercial production of vinegar it has been a subject of extensive but rather technically oriented studies. Suprisingly, the uncommon uncoupling between the inhibited microbial growth and the product formation appears to have been unnoticed. 13 references.

  10. Proteolytic Pathways Induced by Herbicides That Inhibit Amino Acid Biosynthesis

    Science.gov (United States)

    Zulet, Amaia; Gil-Monreal, Miriam; Villamor, Joji Grace; Zabalza, Ana; van der Hoorn, Renier A. L.; Royuela, Mercedes

    2013-01-01

    Background The herbicides glyphosate (Gly) and imazamox (Imx) inhibit the biosynthesis of aromatic and branched-chain amino acids, respectively. Although these herbicides inhibit different pathways, they have been reported to show several common physiological effects in their modes of action, such as increasing free amino acid contents and decreasing soluble protein contents. To investigate proteolytic activities upon treatment with Gly and Imx, pea plants grown in hydroponic culture were treated with Imx or Gly, and the proteolytic profile of the roots was evaluated through fluorogenic kinetic assays and activity-based protein profiling. Results Several common changes in proteolytic activity were detected following Gly and Imx treatment. Both herbicides induced the ubiquitin-26 S proteasome system and papain-like cysteine proteases. In contrast, the activities of vacuolar processing enzymes, cysteine proteases and metacaspase 9 were reduced following treatment with both herbicides. Moreover, the activities of several putative serine protease were similarly increased or decreased following treatment with both herbicides. In contrast, an increase in YVADase activity was observed under Imx treatment versus a decrease under Gly treatment. Conclusion These results suggest that several proteolytic pathways are responsible for protein degradation upon herbicide treatment, although the specific role of each proteolytic activity remains to be determined. PMID:24040092

  11. Inhibition of acid sphingomyelinase by tricyclic antidepressants and analogons

    Directory of Open Access Journals (Sweden)

    Nadine eBeckmann

    2014-09-01

    Full Text Available Amitriptyline, a tricyclic antidepressant, has been used in the clinic to treat a number of disorders, in particular major depression and neuropathic pain. In the 1970s the ability of tricyclic antidepressants to inhibit acid sphingomyelinase (ASM was discovered. The enzyme ASM catalyzes the hydrolysis of sphingomyelin to ceramide. ASM and ceramide were shown to play a crucial role in a wide range of diseases, including cancer, cystic fibrosis, diabetes, Alzheimer’s disease and major depression, as well as viral (e.g. measles virus and bacterial (e.g. Staphylococcus aureus, Pseudomonas aeruginosa infections. Ceramide molecules may act in these diseases by the alteration of membrane biophysics, the self-association of ceramide molecules within the cell membrane and the ultimate formation of larger ceramide-enriched membrane domains/platforms. These domains were shown to serve the clustering of certain receptors such as CD95 and may also act in the above named diseases. The potential to block the generation of ceramide by inhibiting the ASM has opened up new therapeutic approaches for the treatment of these conditions. Since amitriptyline is one of the longest used clinical drugs and side effects are well studied, it could potentially become a cheap and easily accessible medication for patients suffering from these diseases. In this review, we aim to provide an overview of current in vitro and in vivo studies and clinical trials utilizing amitriptyline to inhibit ASM and contemplate possible future applications of the drug.

  12. Phenolic content, antioxidant activities and stimulatory roles of citrus fruits on some lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Irkin Reyhan

    2015-01-01

    Full Text Available In this study, phenolic compounds and antioxidant activities in citrus fruits and their peels were determined, and their stimulatory roles on some lactic acid bacteria were investigated. Phenolic compounds in citrus fruits such as mandarin, lemon, orange and grapefruit were determined either in the juices or in the peel extracts. Total phenolic content was determined in a spectrophotometer at 685 nm using the adapted Folin-Ciocalteu method. Total flavonoid content was measured using LC/MS (liquid chromatography-mass spectrometry. The effects of the fruit juices and peel extracts on the selected lactic acid bacteria (Lactobacillus delbrueckii NRRL B5448, Lb. casei NRRL B1922, Lb. acidophilus NRRL B4495 were investigated. The tested lactic acid bacteria were significantly affected by chlorogenic acid, hesperidin, naringin and caffeic acid compared to the control samples (P≤0.05. Antioxidant properties of fruit samples were also measured using the DPPH (2,2-diphenyl-1-picrylhydrazyl method. The phenolics positively affected the metabolism of bacteria, with the stimulatory effects of the assayed samples being influenced by the phenolic profile.

  13. The inhibitory activity of Lactic acid bacteria isolated from fresh cow cheese

    Directory of Open Access Journals (Sweden)

    Nevijo Zdolec

    2007-04-01

    Full Text Available Lactic acid bacteria are the constituent part of milk microbial flora that could influence the safety of dairy products due production of organic acids, hydrogen peroxide, carbon dioxide and bacteriocins. Taking this in consideration, the objective of this study was to investigate the composition of lactic acid bacteria population in fresh cow cheeses taken from local markets, as well as their antimicrobial capacity. Lactic acid bacteria counts were determined according to ISO 1524:1998 method, biochemical determination using API 50 CHL system, and inhibitory activity against L. monocytogenes NCTC 10527 by agar well diffusion assay. Lactic acid bacteria count in fresh cow cheeses (n=10 ranged from 5.87 to 8.38 log10 CFU g-1. Among 52 MRS isolates collected, 61.54 % were assigned to the Lactococcus lactis subsp. Lactis species, 23.07 % Lactobacillus helveticus, 11.54 % Leuconostoc mesenteroides subsp. cremoris and 3.85 % Leuconostoc mesenteroides subsp. mesenteroides. Antilisterial activity was found in 18 isolates.

  14. The role of spices and lactic acid bacteria as antimicrobial agent to extend the shelf life of metata ayib (traditional Ethiopian spiced fermented cottage cheese).

    Science.gov (United States)

    Geremew, Tsehayneh; Kebede, Ameha; Andualem, Berhanu

    2015-09-01

    Spices and lactic acid bacteria have natural antimicrobial substances and organic compounds having antagonistic activity against microorganisms. The objective of this study was to investigate the role of spices and lactic acid bacteria as antimicrobial agent to extend the shelf life of metata ayib. Antimicrobial activities of spices and lactic acid bacteria (LAB) filtrates were determined by agar well diffusion method against E. coli, S. aureus, S. flexneri and S. peumoniae. Aantimicrobial activity of garlic was found to be the most effective against all the tested pathogens. Inhibition zones of garlic extract against all pathogens was significantly (P ≤ 0.05) greater than the remaining spice extracts. Inhibition zones (12.50 ± 1.00 to 15.50 ± 1.00 mm) of ginger and R. graveolens ethanol extracts against all tested pathogens were significantly (P ≤ 0.05) greater than the remaining solvent extracts. Inhibition zone of O. basilicum ethanol extract against all pathogenic bacteria was significantly (p ≤ 0.05) greater than hexane and acetone extracts. Lactobacillus isolates were shown the highest antimicrobial activity than the other LAB isolates against all pathogens. The synergistic effect of spices together with LAB might be contributed a lot to preserve and extend shelf life of metata ayib. Their antimicrobial activity can reduce the risk of spoilage and pathogenesis. The possible reason of LAB isolates was may be due to production of lactic acid, acetic acid and secondary metabolites like bacteriocins. Aseptic processing of traditional cottage cheese (ayib) is by far needed to minimize risks associated during consumption of metata ayib.

  15. Local domestication of lactic acid bacteria via cassava beer fermentation

    Directory of Open Access Journals (Sweden)

    Alese M. Colehour

    2014-07-01

    Full Text Available Cassava beer, or chicha, is typically consumed daily by the indigenous Shuar people of the Ecuadorian Amazon. This traditional beverage made from cassava tuber (Manihot esculenta is thought to improve nutritional quality and flavor while extending shelf life in a tropical climate. Bacteria responsible for chicha fermentation could be a source of microbes for the human microbiome, but little is known regarding the microbiology of chicha. We investigated bacterial community composition of chicha batches using Illumina high-throughput sequencing. Fermented chicha samples were collected from seven Shuar households in two neighboring villages in the Morona-Santiago region of Ecuador, and the composition of the bacterial communities within each chicha sample was determined by sequencing a region of the 16S ribosomal gene. Members of the genus Lactobacillus dominated all samples. Significantly greater phylogenetic similarity was observed among chicha samples taken within a village than those from different villages. Community composition varied among chicha samples, even those separated by short geographic distances, suggesting that ecological and/or evolutionary processes, including human-mediated factors, may be responsible for creating locally distinct ferments. Our results add to evidence from other fermentation systems suggesting that traditional fermentation may be a form of domestication, providing endemic beneficial inocula for consumers, but additional research is needed to identify the mechanisms and extent of microbial dispersal.

  16. Biocontainment strategies for live lactic acid bacteria vaccine vectors

    Science.gov (United States)

    2010-01-01

    Stability is an important issue when engineering bacteria for use as live vaccine vectors. For the majority of live bacterial vaccines, the antigen-encoding gene is either plasmid located or integrated into the chromosome. Regardless, several safety concerns can be raised for both instances. One concern when using plasmid-encoded antigens is the transfer of antibiotic resistance markers. Alternatively, for chromosomal integrated antigens however, the concern focuses on the spread and possible release of genetically-modified microorganisms (GMM) into the environment, which is problematic. Their recombinant nature calls for a proper bio-containment strategy to be implemented or in place before any realistic attempt at releasing a live bacterial vaccine. No examples of human bacterial vaccines causing problems among animals have been found in the literature but the possibility exists and has to be both tested and evaluated before release of a live bacterial vaccine. The ideal GMM for use in humans should therefore contain the minimal amount of foreign DNA and must not include an antibiotic resistance marker. Furthermore, the possibilities of transgene horizontal transfer must be minimized, and GMM lethality for biocontainment should be achieved in an unconfined environment. PMID:21327129

  17. Local domestication of lactic acid bacteria via cassava beer fermentation.

    Science.gov (United States)

    Colehour, Alese M; Meadow, James F; Liebert, Melissa A; Cepon-Robins, Tara J; Gildner, Theresa E; Urlacher, Samuel S; Bohannan, Brendan J M; Snodgrass, J Josh; Sugiyama, Lawrence S

    2014-01-01

    Cassava beer, or chicha, is typically consumed daily by the indigenous Shuar people of the Ecuadorian Amazon. This traditional beverage made from cassava tuber (Manihot esculenta) is thought to improve nutritional quality and flavor while extending shelf life in a tropical climate. Bacteria responsible for chicha fermentation could be a source of microbes for the human microbiome, but little is known regarding the microbiology of chicha. We investigated bacterial community composition of chicha batches using Illumina high-throughput sequencing. Fermented chicha samples were collected from seven Shuar households in two neighboring villages in the Morona-Santiago region of Ecuador, and the composition of the bacterial communities within each chicha sample was determined by sequencing a region of the 16S ribosomal gene. Members of the genus Lactobacillus dominated all samples. Significantly greater phylogenetic similarity was observed among chicha samples taken within a village than those from different villages. Community composition varied among chicha samples, even those separated by short geographic distances, suggesting that ecological and/or evolutionary processes, including human-mediated factors, may be responsible for creating locally distinct ferments. Our results add to evidence from other fermentation systems suggesting that traditional fermentation may be a form of domestication, providing endemic beneficial inocula for consumers, but additional research is needed to identify the mechanisms and extent of microbial dispersal.

  18. Ganoderic acid T inhibits tumor invasion in vitro and in vivo through inhibition of MMP expression.

    Science.gov (United States)

    Chen, Nian-Hong; Liu, Jian-Wen; Zhong, Jian-Jiang

    2010-01-01

    The traditional Chinese medicinal mushroom, Ganoderma lucidum, has been used in Asia for several thousand years for the prevention and treatment of a variety of diseases, including cancer. In previous work, we purified ganoderic acid T (GA-T) from G. lucidum [28]. In the present study, we investigate the functions of GA-T in terms of its effects on invasion in vitro and metastasis in vivo. A trypan blue dye exclusion assay indicates that GA-T inhibits proliferation of HCT-116 cells, a human colon carcinoma cell line. Cell aggregation and adhesion assays show that GA-T promotes homotypic aggregation and simultaneously inhibits the adhesion of HCT-116 cells to the extracellular matrix (ECM) in a dose-dependent manner.Wound healing assays indicate that GA-T also inhibits the migration of HCT-116 cells in a dose-dependent manner, and it suppresses the migration of 95-D cells, a highly metastatic human lung tumor cell line, in a dose- and time-dependent manner. In addition, GA-T inhibits the nuclear translocation of nuclear factor-kappaB (NF-kappaB) and the degradation of inhibitor of kappaB-alpha (IkappaBalpha), which leads to down-regulated expression of matrix metalloproteinase-9 (MMP-9), inducible nitric oxide synthase (iNOS), and urokinase-type plasminogen activator (uPA). Animal and Lewis Lung Carcinoma (LLC) model experiments demonstrate that GA-T suppresses tumor growth and LLC metastasis and down-regulates MMP-2 and MMP-9 mRNA expression in vivo. Taken together, these results demonstrate that GA-T effectively inhibits cancer cell invasion in vitro and metastasis in vivo, and thus it may act as a potential drug for treating cancer.

  19. Inhibition of norsolorinic acid accumulation to Aspergillus parasiticus by marine actinomycetes

    Science.gov (United States)

    Yan, Peisheng; Shi, Cuijuan; Shen, Jihong; Wang, Kai; Gao, Xiujun; Li, Ping

    2014-11-01

    Thirty-six strains of marine actinomycetes were isolated from a sample of marine sediment collected from the Yellow Sea and evaluated in terms of their inhibitory activity on the growth of Aspergillus parasiticus and the production of norsolorinic acid using dual culture plate assay and agar diffusion methods. Among them, three strains showed strong antifungal activity and were subsequently identified as Streptomyces sp. by 16S rRNA gene sequencing analysis. The supernatant from the fermentation of the MA01 strain was extracted sequentially with chloroform and ethyl acetate, and the activities of the extracts were determined by tip culture assay. The assay results show that both extracts inhibited mycelium growth and toxin production, and the inhibitory activities of the extracts increased as their concentrations increased. The results of this study suggest that marine actinomycetes are biologically important for the control of mycotoxins, and that these bacteria could be used as novel biopesticides against mycotoxins.

  20. Cigarette smoke inhibits airway epithelial cell innate immune responses to bacteria.

    Science.gov (United States)

    Kulkarni, Ritwij; Rampersaud, Ryan; Aguilar, Jorge L; Randis, Tara M; Kreindler, James L; Ratner, Adam J

    2010-05-01

    The human upper respiratory tract, including the nasopharynx, is colonized by a diverse array of microorganisms. While the host generally exists in harmony with the commensal microflora, under certain conditions, these organisms may cause local or systemic disease. Respiratory epithelial cells act as local sentinels of the innate immune system, responding to conserved microbial patterns through activation of signal transduction pathways and cytokine production. In addition to colonizing microbes, these cells may also be influenced by environmental agents, including cigarette smoke (CS). Because of the strong relationship among secondhand smoke exposure, bacterial infection, and sinusitis, we hypothesized that components in CS might alter epithelial cell innate immune responses to pathogenic bacteria. We examined the effect of CS condensate (CSC) or extract (CSE) on signal transduction and cytokine production in primary and immortalized epithelial cells of human or murine origin in response to nontypeable Haemophilus influenzae and Staphylococcus aureus. We observed that epithelial production of interleukin-8 (IL-8) and IL-6 in response to bacterial stimulation was significantly inhibited in the presence of CS (P 0.05 compared to cells without CSC treatment). These results identify a novel oxidant-mediated immunosuppressive role for CS in epithelial cells.

  1. Ricinoleic acid inhibits methanogenesis and fatty acid biohydrogenation in ruminal digesta from sheep and in bacterial cultures.

    Science.gov (United States)

    Ramos Morales, E; Mata Espinosa, M A; McKain, N; Wallace, R J

    2012-12-01

    Ricinoleic acid (RA; 12-hydroxy-cis-9-18:1) is the main fatty acid component of castor oil. Although a precursor for CLA synthesis in lactic acid bacteria, RA was found previously not to form CLA in ruminal digesta but to have some inhibitory properties. The present study was undertaken to evaluate the potential of RA to modulate ruminal biohydrogenation and methanogenesis. Ruminal digesta from 4 sheep receiving a mixed hay-concentrate diet was incubated in vitro with 0.167 g/L of linoleic acid (LA; cis-9,cis-12-18:2) or with a combination of LA and RA or LA and castor oil (LA, RA, and castor oil added to a final concentration of 0.167 g/L) in the presence and absence of lipase. The CLA rumenic acid (cis-9,trans-11-18:2) accumulated when either RA or castor oil and lipase was present. Vaccenic acid (VA; trans-11-18:1) also accumulated, and a decrease of the rate of production of stearic acid (SA; 18:0) was observed. When LA was incubated with castor oil in the absence of lipase, no effects on biohydrogenation were observed. Ricinoleic acid at 0.02 g/L did not affect growth of Butyrivibrio fibrisolvens but it inhibited growth of Butyrivibrio proteoclasticus. Butyrivibrio proteoclasticus but not B. fibrisolvens metabolized RA to 12-hydroxystearate. Linoleic acid metabolism by B. proteoclasticus appeared to be unaffected by RA addition whereas rumenic acid accumulation increased (P = 0.015 at 12 h) when RA was added. A 28% decrease (P = 0.004) in methane was obtained in 24 h in vitro incubations of diluted buffered ruminal fluid with added 0.2 g RA/L. There was no effect on the total concentration of VFA after 24 h as a result of RA addition, but the molar proportions of acetate and butyrate were decreased (P = 0.041 and P methane emissions. In vivo studies are now required to confirm the potential of these additives.

  2. Naturally fermented Jijelian black olives: microbiological characteristics and isolation of lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Karam, Nour-Eddine

    2009-12-01

    Full Text Available A study of the microflora of traditionally fermented black olives in Eastern Algeria is presented. A count of the following microbial groups was carried out: mesophilic bacteria, enterobacteria, lactic acid bacteria (LAB, staphylococci and yeast. In a second phase, the identification and assessment of the technological traits of LAB was performed. Seventeen lactic acid bacteria were isolated and identified. These isolates were represented by two genera: Lactobacillus and Leuconostoc. The results showed that Lactobacillus plantarum was the predominant species in this traditional product.Un estudio sobre la microflora de aceitunas negras fermentada por métodos tradicionales en el Este de Argelia es presentado. Se realizo el siguiente recuento de grupos de microorganismos: bacterias mesófilas, enterobacterias, bacterias ácido lácticas (LAB, staphylococcus y levaduras. En una segunda fase, la identificación y evaluación de aspectos tecnológicos de LAB fue realizada. Setenta bacterias ácido lácticas fueron aisladas e identificadas. Estos aislados contenían principalmente dos géneros: Lactobacillus y Leuconostoc. Los resultados mostraron que Lactobacillus plantarum fue la especie predominante en este producto tradicional.

  3. Acid production in dental plaque after exposure to probiotic bacteria

    Directory of Open Access Journals (Sweden)

    Keller Mette K

    2012-10-01

    Full Text Available Abstract Background The increasing interest in probiotic lactobacilli in health maintenance has raised the question of potential risks. One possible side effect could be an increased acidogenicity in dental plaque. The aim of this study was to investigate the effect of probiotic lactobacilli on plaque lactic acid (LA production in vitro and in vivo. Methods In the first part (A, suspensions of two lactobacilli strains (L. reuteri DSM 17938, L. plantarum 299v were added to suspensions of supragingival dental plaque collected from healthy young adults (n=25. LA production after fermentation with either xylitol or fructose was analyzed. In the second part (B, subjects (n=18 were given lozenges with probiotic lactobacilli (L. reuteri DSM 17938 and ATCC PTA 5289 or placebo for two weeks in a double-blinded, randomized cross-over trial. The concentration of LA in supragingival plaque samples was determined at baseline and after 2 weeks. Salivary counts of mutans streptococci (MS and lactobacilli were estimated with chair-side methods. Results Plaque suspensions with L. reuteri DSM 17938 produced significantly less LA compared with L. plantarum 299v or controls (p Conclusion Lactic acid production in suspensions of plaque and probiotic lactobacilli was strain-dependant and the present study provides no evidence of an increase in plaque acidity by the supply of selected probiotic lactobacilli when challenged by fructose or xylitol. The study protocol was approved by The Danish National Committee on Biomedical Research Ethics (protocol no H-2-2010-112. Trial registration NCT01700712

  4. Effects of lactic acid bacteria and molasses additives on the microbial community and fermentation quality of soybean silage.

    Science.gov (United States)

    Ni, Kuikui; Wang, Fangfang; Zhu, Baoge; Yang, Junxiang; Zhou, Guoan; Pan, Yi; Tao, Yong; Zhong, Jin

    2017-08-01

    The objective was to study effects of lactic acid bacteria (L) and molasses (M) on the microbial community and fermentation quality of soybean silage. Soybean was ensiled with no additive control (C), 0.5% molasses (0.5%M), 0.5%M+L (0.5%ML), 2%M, 2%M+L (2%ML) for 7, 14, 30 and 60days. The M-treated silages could increase the content of lactic acid and decrease butyric acid than control. Besides, higher crude protein was also observed in M-treated silages. With prolonged ensiling time, there was a reduction of the ratio of lactic acid/acetic acid in the 2%M-treated and 2%ML-treated silages. The combined addition of L and 2%M could enhance the account of desirable Lactobacillus and inhibit the growth of undesirable microorganism such as Clostridia and Enterobacter. In summary, the silage quality of soybean was improved with the addition of L and M. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Strategies for improving production performance of probiotic Pediococcus acidilactici viable cell by overcoming lactic acid inhibition.

    Science.gov (United States)

    Othman, Majdiah; Ariff, Arbakariya B; Wasoh, Helmi; Kapri, Mohd Rizal; Halim, Murni

    2017-11-27

    Lactic acid bacteria are industrially important microorganisms recognized for fermentative ability mostly in their probiotic benefits as well as lactic acid production for various applications. Fermentation conditions such as concentration of initial glucose in the culture, concentration of lactic acid accumulated in the culture, types of pH control strategy, types of aeration mode and different agitation speed had influenced the cultivation performance of batch fermentation of Pediococcus acidilactici. The maximum viable cell concentration obtained in constant fed-batch fermentation at a feeding rate of 0.015 L/h was 6.1 times higher with 1.6 times reduction in lactic acid accumulation compared to batch fermentation. Anion exchange resin, IRA 67 was found to have the highest selectivity towards lactic acid compared to other components studied. Fed-batch fermentation of P. acidilactici coupled with lactic acid removal system using IRA 67 resin showed 55.5 and 9.1 times of improvement in maximum viable cell concentration compared to fermentation without resin for batch and fed-batch mode respectively. The improvement of the P. acidilactici growth in the constant fed-batch fermentation indicated the use of minimal and simple process control equipment is an effective approach for reducing by-product inhibition. Further improvement in the cultivation performance of P. acidilactici in fed-bath fermentation with in situ addition of anion-exchange resin significantly helped to enhance the growth of P. acidilactici by reducing the inhibitory effect of lactic acid and thus increasing probiotic production.

  6. Lactic acid bacteria in dairy food: surface characterization and interactions with food matrix components.

    Science.gov (United States)

    Burgain, J; Scher, J; Francius, G; Borges, F; Corgneau, M; Revol-Junelles, A M; Cailliez-Grimal, C; Gaiani, C

    2014-11-01

    This review gives an overview of the importance of interactions occurring in dairy matrices between Lactic Acid Bacteria and milk components. Dairy products are important sources of biological active compounds of particular relevance to human health. These compounds include immunoglobulins, whey proteins and peptides, polar lipids, and lactic acid bacteria including probiotics. A better understanding of interactions between bioactive components and their delivery matrix may successfully improve their transport to their target site of action. Pioneering research on probiotic lactic acid bacteria has mainly focused on their host effects. However, very little is known about their interaction with dairy ingredients. Such knowledge could contribute to designing new and more efficient dairy food, and to better understand relationships between milk constituents. The purpose of this review is first to provide an overview of the current knowledge about the biomolecules produced on bacterial surface and the composition of the dairy matter. In order to understand how bacteria interact with dairy molecules, adhesion mechanisms are subsequently reviewed with a special focus on the environmental conditions affecting bacterial adhesion. Methods dedicated to investigate the bacterial surface and to decipher interactions between bacteria and abiotic dairy components are also detailed. Finally, relevant industrial implications of these interactions are presented and discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Boric acid inhibits embryonic histone deacetylases: A suggested mechanism to explain boric acid-related teratogenicity

    International Nuclear Information System (INIS)

    Di Renzo, Francesca; Cappelletti, Graziella; Broccia, Maria L.; Giavini, Erminio; Menegola, Elena

    2007-01-01

    Histone deacetylases (HDAC) control gene expression by changing histonic as well as non histonic protein conformation. HDAC inhibitors (HDACi) are considered to be among the most promising drugs for epigenetic treatment for cancer. Recently a strict relationship between histone hyperacetylation in specific tissues of mouse embryos exposed to two HDACi (valproic acid and trichostatin A) and specific axial skeleton malformations has been demonstrated. The aim of this study is to verify if boric acid (BA), that induces in rodents malformations similar to those valproic acid and trichostatin A-related, acts through similar mechanisms: HDAC inhibition and histone hyperacetylation. Pregnant mice were treated intraperitoneally with a teratogenic dose of BA (1000 mg/kg, day 8 of gestation). Western blot analysis and immunostaining were performed with anti hyperacetylated histone 4 (H4) antibody on embryos explanted 1, 3 or 4 h after treatment and revealed H4 hyperacetylation at the level of somites. HDAC enzyme assay was performed on embryonic nuclear extracts. A significant HDAC inhibition activity (compatible with a mixed type partial inhibition mechanism) was evident with BA. Kinetic analyses indicate that BA modifies substrate affinity by a factor α = 0.51 and maximum velocity by a factor β = 0.70. This work provides the first evidence for HDAC inhibition by BA and suggests such a molecular mechanism for the induction of BA-related malformations

  8. Diversity and Antimicrobial Properties of Lactic Acid Bacteria Isolated from Rhizosphere of Olive Trees and Desert Truffles of Tunisia

    Science.gov (United States)

    Najjari, Afef; Turki, Yousra; Jaballah, Sana; Boudabous, Abdelatif; Ouzari, Hadda

    2013-01-01

    A total of 119 lactic acid bacteria (LAB) were isolated, by culture-dependant method, from rhizosphere samples of olive trees and desert truffles and evaluated for different biotechnological properties. Using the variability of the intergenic spacer 16S-23S and 16S rRNA gene sequences, the isolates were identified as the genera Lactococcus, Pediococcus, Lactobacillus, Weissella, and Enterococcus. All the strains showed proteolytic activity with variable rates 42% were EPS producers, while only 10% showed the ability to grow in 9% NaCl. In addition, a low rate of antibiotic resistance was detected among rhizospheric enterococci. Furthermore, a strong antibacterial activity against plant and/or pathogenic bacteria of Stenotrophomonas maltophilia, Pantoea agglomerans, Pseudomonas savastanoi, the food-borne Staphylococcus aureus, and Listeria monocytogenes was recorded. Antifungal activity evaluation showed that Botrytis cinerea was the most inhibited fungus followed by Penicillium expansum, Verticillium dahliae, and Aspergillus niger. Most of the active strains belonged to the genera Enterococcus and Weissella. This study led to suggest that environmental-derived LAB strains could be selected for technological application to control pathogenic bacteria and to protect food safety from postharvest deleterious microbiota. PMID:24151598

  9. Fermentation quality and in vitro methane production of sorghum silage prepared with cellulase and lactic acid bacteria.

    Science.gov (United States)

    Khota, Waroon; Pholsen, Suradej; Higgs, David; Cai, Yimin

    2017-11-01

    The effects of lactic acid bacteria (LAB) and cellulase enzyme on fermentation quality, microorganism population, chemical composition and in vitro gas production of sorghum silages were studied. Commercial inoculant Lactobacillus plantarum Chikuso 1 (CH), local selected strain Lactobacillus casei (L. casei) TH 14 and Acremonium cellulase (AC) were used as additives in sorghum silage preparation. Prior to ensiling Sorghum contained 104 LAB and 106 cfu/g fresh matter coliform bacteria. The chemical compositions of sorghum was 26.6% dry matter (DM), 5.2% crude protein (CP), and 69.7% DM for neutral detergent fiber. At 30 days of fermentation after ensiling, the LAB counts increased to a dominant population; the coliform bacteria and molds decreased to below detectable level. All sorghum silages were good quality with a low pH (66.9 g/kg DM). When silage was inoculated with TH14, the pH value was significantly (p<0.05) lower and the CP content significantly (p<0.05) higher compared to control, CH and AC-treatments. The ratio of in vitro methane production to total gas production and DM in TH 14 and TH 14+AC treatments were significantly (p<0.05) reduced compared with other treatments while in vitro dry matter digestibility and gas production did not differ among treatments. The results confirmed that L. casei TH14 could improve sorghum silage fermentation, inhibit protein degradation and decrease methane production.

  10. Diversity and antimicrobial properties of lactic acid bacteria isolated from rhizosphere of olive trees and desert truffles of Tunisia.

    Science.gov (United States)

    Fhoula, Imene; Najjari, Afef; Turki, Yousra; Jaballah, Sana; Boudabous, Abdelatif; Ouzari, Hadda

    2013-01-01

    A total of 119 lactic acid bacteria (LAB) were isolated, by culture-dependant method, from rhizosphere samples of olive trees and desert truffles and evaluated for different biotechnological properties. Using the variability of the intergenic spacer 16S-23S and 16S rRNA gene sequences, the isolates were identified as the genera Lactococcus, Pediococcus, Lactobacillus, Weissella, and Enterococcus. All the strains showed proteolytic activity with variable rates 42% were EPS producers, while only 10% showed the ability to grow in 9% NaCl. In addition, a low rate of antibiotic resistance was detected among rhizospheric enterococci. Furthermore, a strong antibacterial activity against plant and/or pathogenic bacteria of Stenotrophomonas maltophilia, Pantoea agglomerans, Pseudomonas savastanoi, the food-borne Staphylococcus aureus, and Listeria monocytogenes was recorded. Antifungal activity evaluation showed that Botrytis cinerea was the most inhibited fungus followed by Penicillium expansum, Verticillium dahliae, and Aspergillus niger. Most of the active strains belonged to the genera Enterococcus and Weissella. This study led to suggest that environmental-derived LAB strains could be selected for technological application to control pathogenic bacteria and to protect food safety from postharvest deleterious microbiota.

  11. Diversity and Antimicrobial Properties of Lactic Acid Bacteria Isolated from Rhizosphere of Olive Trees and Desert Truffles of Tunisia

    Directory of Open Access Journals (Sweden)

    Imene Fhoula

    2013-01-01

    Full Text Available A total of 119 lactic acid bacteria (LAB were isolated, by culture-dependant method, from rhizosphere samples of olive trees and desert truffles and evaluated for different biotechnological properties. Using the variability of the intergenic spacer 16S-23S and 16S rRNA gene sequences, the isolates were identified as the genera Lactococcus, Pediococcus, Lactobacillus, Weissella, and Enterococcus. All the strains showed proteolytic activity with variable rates 42% were EPS producers, while only 10% showed the ability to grow in 9% NaCl. In addition, a low rate of antibiotic resistance was detected among rhizospheric enterococci. Furthermore, a strong antibacterial activity against plant and/or pathogenic bacteria of Stenotrophomonas maltophilia, Pantoea agglomerans, Pseudomonas savastanoi, the food-borne Staphylococcus aureus, and Listeria monocytogenes was recorded. Antifungal activity evaluation showed that Botrytis cinerea was the most inhibited fungus followed by Penicillium expansum, Verticillium dahliae, and Aspergillus niger. Most of the active strains belonged to the genera Enterococcus and Weissella. This study led to suggest that environmental-derived LAB strains could be selected for technological application to control pathogenic bacteria and to protect food safety from postharvest deleterious microbiota.

  12. Inhibition of various gram-positive and gram-negative bacteria growth on selenium nanoparticle coated paper towels.

    Science.gov (United States)

    Wang, Qi; Larese-Casanova, Philip; Webster, Thomas J

    2015-01-01

    There are wide spread bacterial contamination issues on various paper products, such as paper towels hanging in sink splash zones or those used to clean surfaces, filter papers used in water and air purifying systems, and wrappings used in the food industry; such contamination may lead to the potential spread of bacteria and consequent severe health concerns. In this study, selenium nanoparticles were coated on normal paper towel surfaces through a quick precipitation method, introducing antibacterial properties to the paper towels in a healthy way. Their effectiveness at preventing biofilm formation was tested in bacterial assays involving Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus epidermidis. The results showed significant and continuous bacteria inhibition with about a 90% reduction from 24 to 72 hours for gram-positive bacteria including S. aureus and S. epidermidis. The selenium coated paper towels also showed significant inhibition of gram-negative bacteria like P. aeruginosa and E. coli growth at about 57% and 84%, respectively, after 72 hours of treatment. Therefore, this study established a promising selenium-based antibacterial strategy to prevent bacterial growth on paper products, which may lead to the avoidance of bacteria spreading and consequent severe health concerns.

  13. Competitive Oxidation of Volatile Fatty Acids by Sulfate- and Nitrate-Reducing Bacteria from an Oil Field in Argentina▿ †

    Science.gov (United States)

    Grigoryan, Aleksandr A.; Cornish, Sabrina L.; Buziak, Brenton; Lin, Shiping; Cavallaro, Adriana; Arensdorf, Joseph J.; Voordouw, Gerrit

    2008-01-01

    Acetate, propionate, and butyrate, collectively referred to as volatile fatty acids (VFA), are considered among the most important electron donors for sulfate-reducing bacteria (SRB) and heterotrophic nitrate-reducing bacteria (hNRB) in oil fields. Samples obtained from a field in the Neuquén Basin, western Argentina, had significant activity of mesophilic SRB, hNRB, and nitrate-reducing, sulfide-oxidizing bacteria (NR-SOB). In microcosms, containing VFA (3 mM each) and excess sulfate, SRB first used propionate and butyrate for the production of acetate, which reached concentrations of up to 12 mM prior to being used as an electron donor for sulfate reduction. In contrast, hNRB used all three organic acids with similar kinetics, while reducing nitrate to nitrite and nitrogen. Transient inhibition of VFA-utilizing SRB was observed with 0.5 mM nitrite and permanent inhibition with concentrations of 1 mM or more. The addition of nitrate to medium flowing into an upflow, packed-bed bioreactor with an established VFA-oxidizing SRB consortium led to a spike of nitrite up to 3 mM. The nitrite-mediated inhibition of SRB led, in turn, to the transient accumulation of up to 13 mM of acetate. The complete utilization of nitrate and the incomplete utilization of VFA, especially propionate, and sulfate indicated that SRB remained partially inhibited. Hence, in addition to lower sulfide concentrations, an increase in the concentration of acetate in the presence of sulfate in waters produced from an oil field subjected to nitrate injection may indicate whether the treatment is successful. The microbial community composition in the bioreactor, as determined by culturing and culture-independent techniques, indicated shifts with an increasing fraction of nitrate. With VFA and sulfate, the SRB genera Desulfobotulus, Desulfotignum, and Desulfobacter as well as the sulfur-reducing Desulfuromonas and the NR-SOB Arcobacter were detected. With VFA and nitrate, Pseudomonas spp. were

  14. Heterologous surface display on lactic acid bacteria: non-GMO alternative?

    Science.gov (United States)

    Zadravec, Petra; Štrukelj, Borut; Berlec, Aleš

    2015-01-01

    Lactic acid bacteria (LAB) are food-grade hosts for surface display with potential applications in food and therapy. Alternative approaches to surface display on LAB would avoid the use of recombinant DNA technology and genetically-modified organism (GMO)-related regulatory requirements. Non-covalent surface display of proteins can be achieved by fusing them to various cell-wall binding domains, of which the Lysine motif domain (LysM) is particularly well studied. Fusion proteins have been isolated from recombinant bacteria or from their growth medium and displayed on unmodified bacteria, enabling heterologous surface display. This was demonstrated on non-viable cells devoid of protein content, termed bacteria-like particles, and on various species of genus Lactobacillus. Of the latter, Lactobacillus salivarius ATCC 11741 was recently shown to be particularly amenable for LysM-mediated display. Possible regulatory implications of heterologous surface display are discussed, particularly those relevant for the European Union.

  15. Inhibition of xanthine oxidase by phytic acid and its antioxidative action.

    Science.gov (United States)

    Muraoka, Sanae; Miura, Toshiaki

    2004-02-13

    We examined if phytic acid inhibits the enzymatic superoxide source xanthine oxidase (XO). Half inhibition of XO by phytic acid (IC50) was about 30 mM in the formation of uric acid from xanthine, but generation of the superoxide was greatly affected by phytic acid; the IC50 was about 6 mM, indicating that the superoxide generating domain of XO is more sensitive to phytic acid. The XO activity in intestinal homogenate was also inhibited by phytic acid. However, it was not observed with intestinal homogenate that superoxide generation was more sensitive to phytic acid compared with the formation of uric acid as observed with XO from butter milk. XO-induced superoxide-dependent lipid peroxidation was inhibited by phytic acid, but not by myo-inositol. Reduction of ADP-Fe3+ caused by XO was inhibited by superoxide dismutase, but not phytic acid. The results suggest that phytic acid interferes with the formation of ADP-iron-oxygen complexes that initiate lipid peroxidation. Both phytic acid and myo-inositol inhibited XO-induced superoxide-dependent DNA damage. Mannitol inhibited the DNA strand break. Myo-inositol may act as a hydroxyl radical scavenger. The antioxidative action of phytic acid may be due to not only inhibiting XO, but also preventing formation of ADP-iron-oxygen complexes.

  16. Evolution of Acetic Acid Bacteria During Fermentation and Storage of Wine

    OpenAIRE

    Joyeux, A.; Lafon-Lafourcade, S.; Ribéreau-Gayon, P.

    1984-01-01

    Acetic acid bacteria were present at all stages of wine making, from the mature grape through vinification to conservation. A succession of Gluconobacter oxydans, Acetobacter pasteurianus, and Acetobacter aceti during the course of these stages was noted. Low levels of A. aceti remained in the wine; they exhibited rapid proliferation on short exposure of the wine to air and caused significant increases in the concentration of acetic acid. Higher temperature of wine storage and higher wine pH ...

  17. Influence of Biological Macromolecules and Aquatic Chemistries on the Inhibition of Nitrifying Bacteria by Silver Nanoparticles

    Science.gov (United States)

    Radniecki, T. S.; Anderson, J. W.; Schneider, M. C.; Stankus, D. P.; Nason, J. A.; Semprini, L.

    2010-12-01

    The use of silver nanoparticles (Ag-NP) as a broad spectrum biocide in a wide range of consumer goods has grown exponentially since 2006 (1), which may result in an increased release of Ag-NP into wastewater streams and ultimately the receiving bodies of water. Ammonia oxidizing bacteria (AOB) play a critical role in the global nitrogen cycle through the oxidation of ammonia (NH3) to nitrite (NO2-) and are widely considered to be the most sensitive microbial fauna in the environment being readily inhibited by contaminants, including Ag-NP (2). This research used physiological techniques in combination with physical/chemical assays to characterize the inhibition of Nitrosomonas europaea, the model AOB, by silver ions (Ag+), 3-5 nm Ag-NP, 20 nm Ag-NP and 80 nm Ag-NP under a variety of aqueous chemistries. In addition, the stability of Ag-NP suspensions was examined under a variety of aqueous chemistries including in the presences of divalent cations, chloride anions, natural organic matter (NOM), proteins (BSA) and lipopolysaccharides (alginate). Using the stable Ag-NP/test media suspensions, N. europaea was found to be extremely sensitive to Ag+, 3-5 nm Ag-NP, 20 nm Ag-NP and 80 nm Ag-NP with concentrations of 0.1, 0.12, 0.5 and 1.5 ppm, respectively, resulting in a 50% decrease in nitrification rates. The inhibition was correlated with the amount of Ag+ released into solution. It is suspected that the inhibition observed from Ag-NP exposure is caused by the liberated Ag+. The aquatic chemistry of the test media was found to have a profound influence on the stability of Ag-NP suspensions. The presence of Ag ligands (e.g. EDTA and Cl-) reduced toxicity of Ag-NP through the formation of Ag-ligand complexes with the liberated Ag+. The presence of divalent cations (e.g. Ca2+ or Mg2+) resulted in the rapid aggregation of Ag-NP leading to a decrease in Ag+ liberation and thus a decrease in N. europaea inhibition. The presence of 5 ppm NOM resulted in a highly stable Ag

  18. Lichen-derived caperatic acid and physodic acid inhibit Wnt signaling in colorectal cancer cells.

    Science.gov (United States)

    Paluszczak, Jarosław; Kleszcz, Robert; Studzińska-Sroka, Elżbieta; Krajka-Kuźniak, Violetta

    2018-04-01

    Lichens are a source of secondary metabolites which possess important biological activities, including antioxidant, antibacterial, anti-inflammatory, and cytotoxic effects. The anticancer activity of lichens was shown in many types of tumors, including colorectal cancers (CRC). Several studies revealed that the application of lichen extracts diminished the proliferation of CRC cells and induced apoptosis. Colon carcinogenesis is associated with aberrations in Wnt signaling. Elevated transcriptional activity of β-catenin induces cell survival, proliferation, and migration. Thus, the inhibition of Wnt signaling is a promising therapeutic strategy in colorectal cancer. The aim of this study was the evaluation of the effects of lichen-derived depsides (atranorin, lecanoric acid, squamatic acid) and depsidones (physodic acid, salazinic acid) and a poly-carboxylic fatty acid-caperatic acid, on Wnt signaling in HCT116 and DLD-1 colorectal cancer cell lines. HCT116 cells were more sensitive to the modulatory effects of the compounds. PKF118-310, which was used as a reference β-catenin inhibitor, dose-dependently reduced the expression of the classical β-catenin target gene-Axin2 in both cell lines. Lecanoric acid slightly reduced Axin2 expression in HCT116 cells while caperatic acid tended to reduce Axin2 expression in both cell lines. Physodic acid much more potently decreased Axin2 expression in HCT116 cells than in DLD-1 cells. Physodic acid and caperatic acid also diminished the expression of survivin and MMP7 in a cell line and time-dependent manner. None of the compounds affected the nuclear translocation of β-catenin. This is the first report showing the ability of caperatic acid and physodic acid to modulate β-catenin-dependent transcription.

  19. Production and transformation of dissolved neutral sugars and amino acids by bacteria in seawater

    DEFF Research Database (Denmark)

    Jørgensen, Linda; Lechtenfeld, O.J.; Benner, R.

    2014-01-01

    Dissolved organic matter (DOM) in the ocean consists of a heterogeneous mixture of molecules, most of which are of unknown origin. Neutral sugars and amino acids are among the few recognizable biomolecules in DOM, and the molecular composition of these biomolecules is shaped primarily by biological...... production and degradation processes. This study provides insight into the bioavailability of biomolecules as well as the chemical composition of DOM produced by bacteria. The molecular compositions of combined neutral sugars and amino acids were investigated in DOM produced by bacteria and in DOM remaining...... degradation are not strongly influenced by the initial substrate or bacterial community. The molecular composition of neutral sugars released by bacteria was characterized by a high glucose content (47 mol %) and heterogeneous contributions from other neutral sugars (3–14 mol %). DOM remaining after bacterial...

  20. Different temperatures select distinctive acetic acid bacteria species and promotes organic acids production during Kombucha tea fermentation.

    Science.gov (United States)

    De Filippis, Francesca; Troise, Antonio Dario; Vitaglione, Paola; Ercolini, Danilo

    2018-08-01

    Kombucha is a traditional beverage produced by tea fermentation, carried out by a symbiotic consortium of bacteria and yeasts. Acetic Acid Bacteria (AAB) usually dominate the bacterial community of Kombucha, driving the fermentative process. The consumption of this beverage was often associated to beneficial effects for the health, due to its antioxidant and detoxifying properties. We characterized bacterial populations of Kombucha tea fermented at 20 or 30 °C by using culture-dependent and -independent methods and monitored the concentration of gluconic and glucuronic acids, as well as of total polyphenols. We found significant differences in the microbiota at the two temperatures. Moreover, different species of Gluconacetobacter were selected, leading to a differential abundance of gluconic and glucuronic acids. Copyright © 2018 Elsevier Ltd. All rights reserved.