Sample records for aerobic bacteria lactic

  1. Lactic Acid Bacteria

    NSDL National Science Digital Library

    This on-line exercise is focused on lactic acid bacteria, a group of related bacteria that produce lactic acid as a result of carbohydrate fermentation. It includes a protocol for the enrichment of lactic acid bacteria from enriched samples (like yogurt, sauerkraut, decaying plant matter, and tooth plaque). Three parameters are measured: growth, culture diversity, and pH. The exercise also includes instructions for the isolation of some of these bacteria by using the streak-plate method.

  2. Effect of applying lactic acid bacteria and propionic acid on fermentation quality and aerobic stability of oats-common vetch mixed silage on the Tibetan plateau.

    PubMed

    Zhang, Jie; Guo, Gang; Chen, Lei; Li, Junfeng; Yuan, Xianjun; Yu, Chengqun; Shimojo, Masataka; Shao, Tao

    2015-06-01

    The objective of this study was to evaluate effects of lactic acid bacteria and propionic acid on the fermentation quality and aerobic stability of oats-common vetch mixed silage by using a small-scale fermentation system on the Tibetan plateau. (i) An inoculant (Lactobacillus plantarum) (L) or (ii) propionic acid (P) or (iii) inoculant?+?propionic acid (PL) were used as additives. After fermenting for 60 days, silos were opened and the aerobic stability was tested for the following 15 days. The results showed that all silages were well preserved with low pH and NH3 -N, and high lactic acid content and V-scores. L and PL silages showed higher (P?lactic acid and crude protein content than the control silage. P silage inhibited lactic acid production. Under aerobic conditions, L silage had similar yeast counts as the control silage (>?10(5) ?cfu/g fresh matter (FM)); however, it numerically reduced aerobic stability for 6?h. P and PL silages showed fewer yeasts (aerobic stability (>?360?h). The result suggested that PL is the best additive as it could not only improved fermentation quality, but also aerobic stability of oats-common vetch mixed silage on the Tibetan plateau. PMID:25494579

  3. Lactic acid bacteria of meat and meat products.

    PubMed

    Egan, A F

    1983-09-01

    When the growth of aerobic spoilage bacteria is inhibited, lactic acid bacteria may become the dominant component of the microbial flora of meats. This occurs with cured meats and with meats packaged in films of low gas permeability. The presence of a flora of psychrotrophic lactic acid bacteria on vacuum-packaged fresh chilled meats usually ensures that shelf-life is maximal. When these organisms spoil meats it is generally by causing souring, however other specific types of spoilage do occur. Some strains cause slime formation and greening of cured meats, and others may produce hydrogen sulphide during growth on vacuum-packaged beef. The safety and stability of fermented sausages depends upon fermentation caused by lactic acid bacteria. Overall the presence on meats of lactic acid bacteria is more desirable than that of the types of bacteria they have replaced. PMID:6354082

  4. Effect of inoculation of mesophilic lactic acid bacteria on microbial and sensory changes of minced goat meat during storage under vacuum and subsequent aerobic storage.

    PubMed

    Babji, Y; Murthy, T R

    2000-02-01

    Minced goat meat inoculated with cell suspensions of Lactococcus lactis ssp lactis (Lc. lactis) or Lactobacillus plantarum was stored under vacuum in PETPE film at 4°C and transferred to aerobic storage for 7 days in LDPE bags. During storage under vacuum, the lactic counts of the inoculated samples dropped followed by the development of spontaneous lactic flora. The pH of meat was lower in the treated samples than in the control. Towards the end of vacuum storage cell densities were lower than those in the control only for psychrotrophs in L. plantarum treatment and coliforms and staphylococcal counts in Lc. lactis treatment. There were increases in lactic counts in both treated and control samples during aerobic storage after previous vacuum storage of 18 days in trial 1 and 9 days in trial 2 with reductions in the counts of different bacterial groups and deterioration in colour of the treated samples compared with the control. When goat meat chunks were surface sanitized in alcohol and treated with lactic cell suspension and vacuum stored, there was development of acid and salty taste (acceptable) in the treated samples whereas the control showed a bland taste. PMID:22060616

  5. Dry matter and nutritional losses during aerobic deterioration of corn and sorghum silages as influenced by different lactic acid bacteria inocula.

    PubMed

    Tabacco, E; Righi, F; Quarantelli, A; Borreani, G

    2011-03-01

    The economic damage that results from aerobic deterioration of silage is a significant problem for farm profitability and feed quality. This paper quantifies the dry matter (DM) and nutritional losses that occur during the exposure of corn and sorghum silages to air over 14 d and assesses the possibility of enhancing the aerobic stability of silages through inoculation with lactic acid bacteria (LAB). The trial was carried out in Northern Italy on corn (50% milk line) and grain sorghum (early dough stage) silages. The crops were ensiled in 30-L jars, without a LAB inoculant (C), with a Lactobacillus plantarum inoculum (LP), and with a Lactobacillus buchneri inoculum (LB; theoretical rate of 1 × 10(6) cfu/g of fresh forage). The pre-ensiled material, the silage at silo opening, and the aerobically exposed silage were analyzed for DM content, fermentative profiles, yeast and mold count, starch, crude protein, ash, fiber components, 24-h and 48-h DM digestibility and neutral detergent fiber (NDF) degradability. The yield and nutrient analysis data of the corn and sorghum silages were used as input for Milk2006 to estimate the total digestible nutrients, net energy of lactation, and milk production per Mg of DM. The DM fermentation and respiration losses were also calculated. The inocula influenced the in vitro NDF digestibility at 24h, the net energy for lactation (NE(L)), and the predicted milk yield per megagram of DM, whereas the length of time of air exposure influenced DM digestibility at 24 and 48 h, the NE(L), and the predicted milk yield per megagram of DM in the corn silages. The inocula only influenced the milk yield per megagram of DM and the air exposure affected the DM digestibility at 24h, the NE(L), and the milk yield per megagram of DM in the sorghum silages. The milk yield, after 14 d of air exposure, decreased to 1,442, 1,418, and 1,277 kg/Mg of DM for C, LB, and LP corn silages, respectively, compared with an average value of 1,568 kg of silage at opening. In the sorghum silages, the milk yield, after 14 d of air exposure, decreased to 1,226, 1,278, and 1,250 kg/Mg of DM for C, LB, and LP, respectively. When the estimated milk yield per megagram of harvested DM of corn and sorghum silage were related to mold count, it was shown that the loss of potential milk production occurred when the mold count exceeded 4 log cfu/g of silage, and it was almost halved when the mold count reached values greater than 8 log cfu/g of silage. Inoculation with L. buchneri, at a rate of 1 × 10(6) cfu/g of fresh forage, enhanced the stability of the silage after exposure to air, and, consequently, contributed to maintaining the nutritional value of the harvested forage over time, for air exposure up to 7 d. PMID:21338806

  6. Iron requirement and search for siderophores in lactic acid bacteria

    Microsoft Academic Search

    Ashok Pandey; Françoise Bringel; Jean-Marie Meyer

    1994-01-01

    Twenty-three strains of lactic acid bacteria belonging to the genera Lactobacillus, Lactococcus, Leuconostoc, Pediococcus or Carnobacterium, were studied for growth and siderophore production under controlled iron-starvation conditions. No growth differences were observed in the media either supplemented with or depleted of iron, in agitated (aerobic) or static (microaerophilic) growth conditions, and none of the tested species produced siderophores. Growth studies

  7. Evolutionary Genomics of Lactic Acid Bacteria

    Microsoft Academic Search

    Kira S. Makarova; Eugene V. Koonin

    2007-01-01

    The lactic acid bacteria (LAB) might be the most numerous group of bacteria linked to humans. They are naturally asso- ciated with mucosal surfaces, particularly the gastrointestinal tract, and are also indigenous to food-related habitats, includ- ing plant (fruits, vegetables, and cereal grains), wine, milk, and meat environments (60, 61). The LAB include both important pathogens, e.g., several Streptococcus species,

  8. The proteolytic system of lactic acid bacteria.

    PubMed

    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. PMID:8172695

  9. Discovering lactic acid bacteria by genomics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This review summarizes a collection of lactic acid bacteria that are now undergoing genomic sequencing and analysis. Summaries are presented on 20 different species, with each overview discussing the organisms fundamental and practical significance, environmental habitat, and its role in fermentati...

  10. Discovering lactic acid bacteria by genomics

    Microsoft Academic Search

    Todd Klaenhammer; Eric Altermann; Fabrizio Arigoni; Alexander Bolotin; Fred Breidt; Jeffrey Broadbent; Raul Cano; Stephane Chaillou; Josef Deutscher; Mike Gasson; Maarten van de Gutche; Jean Guzzo; Axel Hartke; Trevor Hawkins; Pascal Hols; Robert W. Hutkins; Michiel Kleerebezem; Jan Kok; Oscar Kuipers; Mark Lubbers; Emanuelle Maguin; Larry McKay; David Mills; Arjen Nauta; Ross Overbeek; Herman Pel; David Pridmore; Milton Saier; Douwe van Sinderen; Alexei Sorokin; James Steele; Daniel OSullivan; Willem de Vos; Bart Weimer; Monique Zagorec; Roland Seizen

    2002-01-01

    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 fermentation, bioprocessing, or probiotics. For those projects where genome sequence data were available by March 2002, summaries include a listing

  11. Anchoring of proteins to lactic acid bacteria

    Microsoft Academic Search

    Girbe Buist; Kees Leenhouts; Jan Kok

    1999-01-01

    The anchoring of proteins to the cell surface of lactic acid bacteria (LAB) using genetic techniques is an exciting and emerging research area that holds great promise for a wide variety of biotechnological applications. This paper reviews five different types of anchoring domains that have been explored for their efficiency in attaching hybrid proteins to the cell membrane or cell

  12. Food phenolics and lactic acid bacteria

    Microsoft Academic Search

    Héctor Rodríguez; José Antonio Curiel; José María Landete; Blanca de las Rivas; Félix López de Felipe; Carmen Gómez-Cordovés; José Miguel Mancheño; Rosario Muñoz

    2009-01-01

    Phenolic compounds are important constituents of food products of plant origin. These compounds are directly related to sensory characteristics of foods such as flavour, astringency, and colour. In addition, the presence of phenolic compounds on the diet is beneficial to health due to their chemopreventive activities against carcinogenesis and mutagenesis, mainly due to their antioxidant activities. Lactic acid bacteria (LAB)

  13. Precision genome engineering in lactic acid bacteria.

    PubMed

    van Pijkeren, Jan Peter; Britton, Robert A

    2014-08-29

    Innovative new genome engineering technologies for manipulating chromosomes have appeared in the last decade. One of these technologies, recombination mediated genetic engineering (recombineering) allows for precision DNA engineering of chromosomes and plasmids in Escherichia coli. Single-stranded DNA recombineering (SSDR) allows for the generation of subtle mutations without the need for selection and without leaving behind any foreign DNA. In this review we discuss the application of SSDR technology in lactic acid bacteria, with an emphasis on key factors that were critical to move this technology from E. coli into Lactobacillus reuteri and Lactococcus lactis. We also provide a blueprint for how to proceed if one is attempting to establish SSDR technology in a lactic acid bacterium. The emergence of CRISPR-Cas technology in genome engineering and its potential application to enhancing SSDR in lactic acid bacteria is discussed. The ability to perform precision genome engineering in medically and industrially important lactic acid bacteria will allow for the genetic improvement of strains without compromising safety. PMID:25185700

  14. Metabolic engineering of sugar catabolism in lactic acid bacteria

    Microsoft Academic Search

    Willem M. Vos

    1996-01-01

    Lactic acid bacteria are characterized by a relatively simple sugar fermentation pathway that, by definition, results in the formation of lactic acid. The extensive knowledge of traditional pathways and the accumulating genetic information on these and novel ones, allows for the rerouting of metabolic processes in lactic acid bacteria by physiological approaches, genetic methods, or a combination of these two.

  15. Biosynthesis of bacteriocins in lactic acid bacteria

    Microsoft Academic Search

    Ingolf F. Nes; Dzung Bao Diep; Leiv Sigve Håvarstein; May Bente Brurberg; Vincent Eijsink; Helge Holo

    1996-01-01

    A large number of new bacteriocins in lactic acid bacteria (LAB) has been characterized in recent years. Most of the new bacteriocins belong to the class II bacteriocins which are small (30–100 amino acids) heat-stable and commonly not post-translationally modified. While most bacteriocin producers synthesize only one bacteriocin, it has been shown that several LAB produce multiple bacteriocins (2–3 bacteriocins).

  16. Genetics of Lactic Acid Bacteria

    Microsoft Academic Search

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

    2008-01-01

    Many meat (or fish) products, obtained by the fermentation of meat originating from various animals by the flora that naturally\\u000a contaminates it, are part of the human diet since millenaries. Historically, the use of bacteria as starters for the fermentation\\u000a of meat, to produce dry sausages, was thus performed empirically through the endogenous micro-biota, then, by a volunteer\\u000a addition of

  17. Freeze-drying of lactic acid bacteria.

    PubMed

    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. PMID:25428024

  18. Antagonism of Lactic Acid Bacteria against Phytopathogenic Bacteria

    PubMed Central

    Visser, Ronèl; Holzapfel, Wilhelm H.; Bezuidenhout, Johannes J.; Kotzé, Johannes M.

    1986-01-01

    A variety of lactic acid bacteria, isolated from plant surfaces and plant-associated products, were found to be antagonistic to test strains of the phytopathogens Xanthomonas campestris, Erwinia carotovora, and Pseudomonas syringae. Effective “in vitro” inhibition was found both on agar plates and in broth cultures. In pot trials, treatment of bean plants with a Lactobacillus plantarum strain before inoculation with P. syringae caused a significant reduction of the disease incidence. Images PMID:16347150

  19. Cancer chemopreventive effects of lactic acid bacteria.

    PubMed

    Kim, Jong-Eun; Kim, Ji Yeon; Lee, Ki Won; Lee, Hyong Joo

    2007-08-01

    Lactic acid bacteria (LAB) provide several potential health and nutritional benefits, including improving the nutritional value of food, controlling serum cholesterol levels, and controlling some types of cancer. Numerous in vitro, in vivo, human, and epidemiological studies have provided evidence of the chemopreventive effects of LAB on colon, bladder, liver, breast, and gastric cancers. These effects act via diverse mechanisms, including alteration of the gastrointestinal microflora, enhancement of the host's immune response, and antioxidative and antiproliferative activities. This review discusses the recent progresses on the chemopreventive effects of LAB on specific cancer types and the underlying molecular mechanisms. PMID:18051589

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

    PubMed

    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 in sensory rankings. It was concluded that lactic acid bacteria may not be necessary for successful cocoa fermentation. PMID:25889523

  1. Aerobic Mesophilic Bacteria in Composts

    Microsoft Academic Search

    D. M. Webley

    1948-01-01

    IN a previous communication1, an account was given of the activity of the thermophilic flora which develops in composts made from grass cuttings (lawn mowings). This thermophilic flora can be seen as a white coating on the cuttings, particularly in the upper layers during the high-temperature phase. From it true and facultative thermophilic bacteria were isolated. Recently, in addition, evidence

  2. Lactic acid bacteria of foods and their current taxonomy

    Microsoft Academic Search

    Michael E. Stiles; Wilhelm H. Holzapfel

    1997-01-01

    Application of molecular genetic techniques to determine the relatedness of food-associated lactic acid bacteria has resulted in significant changes in their taxonomic classification. During the 1980s the genus Streptococcus was separated into the three genera Enterococcus, Lactococcus and Streptococcus. The lactic acid bacteria associated with foods now include species of the genera Carnobacterium, Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Oenococcus, Pediococcus, Streptococcus,

  3. Antagonistic activity in plant-associated lactic acid bacteria

    Microsoft Academic Search

    Thomas Müller; Undine Behrendt; Marina Müller

    1996-01-01

    A total of 256 strains of lactic acid bacteria isolated from forage grasses were screened for antagonistic activities under conditions where the effects of organic acids and hydrogen peroxide were minimised. Thirty seven strains were shown to inhibit the growth of other lactic acid bacteria in the agar spot test with viable cells. Cell free supernatants from 16 of these

  4. Towards lactic acid bacteria-based biorefineries.

    PubMed

    Mazzoli, Roberto; Bosco, Francesca; Mizrahi, Itzhak; Bayer, Edward A; Pessione, Enrica

    2014-11-15

    Lactic acid bacteria (LAB) have long been used in industrial applications mainly as starters for food fermentation or as biocontrol agents or as probiotics. However, LAB possess several characteristics that render them among the most promising candidates for use in future biorefineries in converting plant-derived biomass-either from dedicated crops or from municipal/industrial solid wastes-into biofuels and high value-added products. Lactic acid, their main fermentation product, is an attractive building block extensively used by the chemical industry, owing to the potential for production of polylactides as biodegradable and biocompatible plastic alternative to polymers derived from petrochemicals. LA is but one of many high-value compounds which can be produced by LAB fermentation, which also include biofuels such as ethanol and butanol, biodegradable plastic polymers, exopolysaccharides, antimicrobial agents, health-promoting substances and nutraceuticals. Furthermore, several LAB strains have ascertained probiotic properties, and their biomass can be considered a high-value product. The present contribution aims to provide an extensive overview of the main industrial applications of LAB and future perspectives concerning their utilization in biorefineries. Strategies will be described in detail for developing LAB strains with broader substrate metabolic capacity for fermentation of cheaper biomass. PMID:25087936

  5. High efficiency recombineering in lactic acid bacteria.

    PubMed

    van Pijkeren, Jan-Peter; Britton, Robert A

    2012-05-01

    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 lactic acid bacteria. Mutations were incorporated in the chromosome of Lactobacillus reuteri and Lactococcus lactis without selection at frequencies ranging between 0.4% and 19%. Whole genome sequence analysis showed that ssDNA recombineering is specific and not hypermutagenic. To highlight the utility of ssDNA recombineering we reduced the intrinsic vancomymycin resistance of L. reuteri >100-fold. By creating a single amino acid change in the D-Ala-D-Ala ligase enzyme we reduced the minimum inhibitory concentration for vancomycin from >256 to 1.5?µg/ml, well below the clinically relevant minimum inhibitory concentration. Recombineering thus allows high efficiency mutagenesis in lactobacilli and lactococci, and may be used to further enhance beneficial properties and safety of strains used in medicine and industry. We expect that this work will serve as a blueprint for the adaptation of ssDNA recombineering to other gram-positive bacteria. PMID:22328729

  6. Exopolysaccharides from sourdough lactic acid bacteria.

    PubMed

    Galle, Sandra; Arendt, Elke K

    2014-01-01

    The use of sourdough improves the quality and increases the shelf life of bread. The positive effects are associated with metabolites produced by lactic acid bacteria (LAB) during sourdough fermentation, including organic acids, exopolysaccharides (EPS), and enzymes. EPS formed during sourdough fermentation by glycansucrase activity from sucrose influence the viscoelastic properties of the dough and beneficially affect the texture and shelf life (in particular, starch retrogradation) of bread. Accordingly, EPS have the potential to replace hydrocolloids currently used as bread improvers and meet so the consumer demands for a reduced use of food additives. In this review, the current knowledge about the functional aspects of EPS formation by sourdough LAB especially in baking applications is summarized. PMID:24499068

  7. Exploiting expolysaccharides from lactic acid bacteria.

    PubMed

    Jolly, Laure; Vincent, Sébastien J F; Duboc, Philippe; Neeser, Jean-Richard

    2002-08-01

    Microbial exopolysaccharides (EPSs) synthesized by lactic acid bacteria (LAB) play a major role in the manufacturing of fermented dairy products. EPS production is characterized by a large variety in terms of quantity, chemical composition, molecular size, charge, type of sidechains and rigidity of the molecules. Monosaccharide unit's composition, linkages, charge and size determine the EPS' intrinsic properties and their interactions with other milk constituents. EPSs contribute to texture, mouthfeel, taste perception and stability of the final product. Furthermore, it was reported that EPS from food grade organisms, particularly LAB, have potential as food additives and as functional food ingredients with both health and economic benefits. A better understanding of structure-function relationships of EPS in a dairy food matrix and of EPS biosynthesis remain two major challenges for further applications of EPS and the engineering of functional polysaccharides. PMID:12369204

  8. Health and nutritional benefits from lactic acid bacteria.

    PubMed

    Gilliland, S E

    1990-09-01

    There are several potential health or nutritional benefits possible from some species of lactic acid bacteria. Among these are: improved nutritional value of food, control of intestinal infections, improved digestion of lactose, control of some types of cancer, and control of serum cholesterol levels. Some potential benefits may result from growth and action of the bacteria during the manufacture of cultured foods. Some may result from growth and action of certain species of the lactic acid bacteria in the intestinal tract following ingestion of foods containing them. In selecting a culture to produce a specific benefit it is necessary to consider not only the wide variation among species of the lactic acid bacteria but also that among strains within a given species. With the possible exception of improving lactose utilization by persons who are lactose maldigestors, no specific health or nutritional claims can yet be made for the lactic acid bacteria. PMID:2271223

  9. Clinical importance of lactic acid bacteria: a short review.

    PubMed

    Kumari, Archana; Catanzaro, Roberto; Marotta, Francesco

    2011-12-01

    Lactic acid bacteria (LAB) were used extensively as starter cultures in food fermentation. Some of the health benefits which have been claimed for lactic acid bacteria as probiotics include the following: improvement of the normal microflora, prevention of infectious diseases and food allergies, reduction of serum cholesterol, anticarcinogenic activity, stabilization of the gut mucosal barrier, immune adjuvant properties, alleviation of intestinal bowel disease symptoms and improvement in the digestion of lactose in intolerant hosts. The present study is aimed to brief review the some clinical importance of lactic acid bacteria (www.actabiomedica.it). PMID:22783712

  10. Lactic acid bacteria and human health.

    PubMed

    Gorbach, S L

    1990-02-01

    Although claims for health and nutritional benefits have been made for lactic acid bacteria in fermented dairy products for nearly a century, the nutritional and therapeutic value of these organisms is still controversial. This article will review the scientific basis of these claims. There are numerous studies showing fermentation of food with lactobacilli increase the quantity, availability, digestibility, and assimilability of nutrients. The basis for this conclusion comes from direct measurements of vitamin synthesis and from increased feed efficiency when fermented products are fed to animals. There have been a number of studies showing that various fermented dairy products lower serum cholesterol levels in humans and animals. These studies are reviewed and the validity of these findings are assessed. A summary of the evidence indicating that lactase deficient individuals can eat yogurt and the mechanisms involved in this toleration is reviewed. The role of fermented dairy products in inhibiting tumor growth and chemically induced tumors in animals is discussed and the possible mechanisms involved in this protective effect are reviewed. Fermented dairy products and lypholized lactobacilli preparations have been shown to be useful in treating and preventing various intestinal infections including; salmonellosis, shigellosis and antibiotic induced diarrhea. In this context a specific lactobacillus designated GG has been shown to be useful in treating recurring diarrhea caused by a toxin produced by Clostridium difficile. PMID:2109988

  11. Importance of lactic acid bacteria in Asian fermented foods

    PubMed Central

    2011-01-01

    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. PMID:21995342

  12. Biology of Moderately Halophilic Aerobic Bacteria

    PubMed Central

    Ventosa, Antonio; Nieto, Joaquín J.; Oren, Aharon

    1998-01-01

    The moderately halophilic heterotrophic aerobic bacteria form a diverse group of microorganisms. The property of halophilism is widespread within the bacterial domain. Bacterial halophiles are abundant in environments such as salt lakes, saline soils, and salted food products. Most species keep their intracellular ionic concentrations at low levels while synthesizing or accumulating organic solutes to provide osmotic equilibrium of the cytoplasm with the surrounding medium. Complex mechanisms of adjustment of the intracellular environments and the properties of the cytoplasmic membrane enable rapid adaptation to changes in the salt concentration of the environment. Approaches to the study of genetic processes have recently been developed for several moderate halophiles, opening the way toward an understanding of haloadaptation at the molecular level. The new information obtained is also expected to contribute to the development of novel biotechnological uses for these organisms. PMID:9618450

  13. Barriers to application of genetically modified lactic acid bacteria.

    PubMed

    Verrips, C T; van den Berg, D J

    1996-10-01

    To increase the acceptability of food products containing genetically modified microorganisms it is necessary to provide in an early stage to the consumers that the product is safe and that the product provide a clear benefit to the consumer. To comply with the first requirement a systematic approach to analyze the probability that genetically modified lactic acid bacteria will transform other inhabitants of the gastro- intestinal (G/I) tract or that these lactic acid bacteria will pick up genetic information of these inhabitants has been proposed and worked out to some degree. From this analysis it is clear that reliable data are still missing to carry out complete risk assessment. However, on the basis of present knowledge, lactic acid bacteria containing conjugative plasmids should be avoided. Various studies show that consumers in developed countries will accept these products when they offer to them health or taste benefits or a better keepability. For the developing countries the biggest challenge for scientists is most likely to make indigenous fermented food products with strongly improved microbiological stability due to broad spectra bacteriocins produced by lactic acid bacteria. Moreover, these lactic acid bacteria may contribute to health. PMID:8879412

  14. Fermentation Characteristics and Lactic Acid Bacteria Succession of Total Mixed Ration Silages Formulated with Peach Pomace

    PubMed Central

    Hu, Xiaodong; Hao, Wei; Wang, Huili; Ning, Tingting; Zheng, Mingli; Xu, Chuncheng

    2015-01-01

    The objective of this study was to assess the use of peach pomace in total mixed ration (TMR) silages and clarify the differences in aerobic stability between TMR and TMR silages caused by lactic acid bacteria (LAB). The TMR were prepared using peach pomace, alfalfa hay or Leymus chinensis hay, maize meal, soybean meal, cotton meal, limestone, a vitamin-mineral supplement, and salt in a ratio of 6.0:34.0:44.4:7.0:5.0:2.5:1.0:0.1 on a dry matter (DM) basis. Fermentation quality, microbial composition, and the predominant LAB were examined during ensiling and aerobic deterioration. The results indicated that the TMR silages with peach pomace were well fermented, with low pH and high lactic acid concentrations. The aerobic stability of TMR silages were significantly higher than that of TMR. Compared with TMR silages with alfalfa hay, TMR silage with Leymus chinensis hay was much more prone to deterioration. Although the dominant LAB were not identical in TMR, the same dominant species, Lactobacillus buchneri and Pediococcus acidilactici, were found in both types of TMR silages after 56 d of ensiling, and they may play an important role in the aerobic stability of TMR silages. PMID:25656205

  15. Biotechnology of lactic acid bacteria with special reference to bacteriophage resistance

    Microsoft Academic Search

    Charles Daly; Gerald F. Fitzgerald; Ruth Davis

    1996-01-01

    Lactic acid bacteria play an important role in many food and feed fermentations. In recent years major advances have been made in unravelling the genetic and molecular basis of significant industrial traits of lactic acid bacteria. Bacteriophages which can infect and destroy lactic acid bacteria pose a particularly serious threat to dairy fermentations that can result in serious economic losses.

  16. Perspectives of engineering lactic acid bacteria for biotechnological polyol production

    Microsoft Academic Search

    Vicente Monedero; Gaspar Pérez-Martínez; María J. Yebra

    2010-01-01

    Polyols are sugar alcohols largely used as sweeteners and they are claimed to have several health-promoting effects (low-caloric,\\u000a low-glycemic, low-insulinemic, anticariogenic, and prebiotic). While at present chemical synthesis is the only strategy able\\u000a to assure the polyol market demand, the biotechnological production of polyols has been implemented in yeasts, fungi, and\\u000a bacteria. Lactic acid bacteria (LAB) are a group of

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

    Microsoft Academic Search

    Micaela Pescuma; Elvira María Hébert; Fernanda Mozzi

    2010-01-01

    Whey protein concentrate (WPC) is employed as functional food ingredient because of its nutritional value and emulsifying properties. However, the major whey protein ?-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

  18. Polyphasic characterization of the lactic acid bacteria in kefir

    Microsoft Academic Search

    Isabelle Mainville; Normand Robert; Byong Lee; Edward R. Farnworth

    2006-01-01

    The lactic acid bacteria of kefir were isolated and characterized using phenotypical, biochemical, and genotypical methods. Polyphasic analyses of results permitted the identification of the microflora to the strain level. The genus Lactobacillus was represented by the species Lb. kefir and Lb. kefiranofaciens. Both subspecies of Lactococcus lactis (lactis and cremoris) were isolated. Leuconostoc mesenteroides subsp. cremoris was also found.The

  19. Phylogenomic reconstruction of lactic acid bacteria: an update

    Microsoft Academic Search

    Zhi-Gang Zhang; Zhi-Qiang Ye; Li Yu; Peng Shi

    2011-01-01

    BACKGROUND: Lactic acid bacteria (LAB) are important in the food industry for the production of fermented food products and in human health as commensals in the gut. However, the phylogenetic relationships among LAB species remain under intensive debate owing to disagreements among different data sets. RESULTS: We performed a phylogenetic analysis of LAB species based on 232 genes from 28

  20. Modelling strategies for the industrial exploitation of lactic acid bacteria

    Microsoft Academic Search

    Eddy J. Smid; Bas Teusink

    2006-01-01

    Lactic acid bacteria (LAB) have a long tradition of use in the food industry, and the number and diversity of their applications has increased considerably over the years. Traditionally, process optimization for these applications involved both strain selection and trial and error. More recently, metabolic engineering has emerged as a discipline that focuses on the rational improvement of industrially useful

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

    PubMed Central

    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 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. PMID:21995776

  2. Malolactic activity of lactic acid bacteria during sauerkraut fermentation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The frequency of lactic acid bacteria (LAB) involved in sauerkraut fermentation with (MDC+) or without (MDC-) the ability to decarboxylate malic acid was determined. The MDC+ phenotype was found in >99% of homofermentative LAB isolated from commercial fermentations. In contrast, heterofermentative...

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

    PubMed

    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. PMID:17921264

  4. DNA Fingerprinting of Lactic Acid Bacteria in Sauerkraut Fermentations? † ‡

    PubMed Central

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

    2007-01-01

    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. PMID:17921264

  5. CLA production from ricinoleic acid by lactic acid bacteria

    Microsoft Academic Search

    Akinori Ando; Jun Ogawa; Shigenobu Kishino; Sakayu Shimizu

    2003-01-01

    The ability to produce CLA from ricinoleic acid is widely distributed in lactic acid bacteria. Washed cells of Lactobacillus plantarum JCM 1551 were selected as a potential catalyst for CLA production from ricinoleic acid. Cells cultivated in medium supplemented\\u000a with a mixture of ?-linolenic acid and linoleic acid showed enhanced CLA productivity. Under optimal reaction conditions,\\u000a with the free acid

  6. Lactic acid bacteria in a changing legislative environment.

    PubMed

    Feord, Jean

    2002-08-01

    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, processing aids, feed additives and dietary supplements. On a global basis, there are different approaches taken by the various regulatory authorities. While in Europe, the national legislation is gradually being harmonized, predominantly through the Novel Foods Regulation, there is still a wide disparity between the stringency of regulation of microbial products fed to animals and the comparatively relaxed approach to 'non-novel' microbial products intended for human consumption. In the United States, the onus is on self-regulation of the manufacturer, with the Generally Recognised As Safe (GRAS) and Dietary Supplement Health Education Act (DSHEA) notification schemes encouraging industry to be more open about the ingredients they market. In Japan, the Foods for Special Health Use system continues to gain recognition as more products are approved, and is a potential model for other countries in regulating functional foods. Despite the different approaches to regulating these products, safety of microorganisms such as lactic acid bacteria in the food chain is paramount in all countries. This paper discusses the regulatory requirements of microbial products, predominantly lactic acid bacteria within the global markets, focusing mainly on the developments in Europe. PMID:12369202

  7. Lactic acid bacteria in fermented foods in Thailand.

    PubMed

    Tanasupawat, S; Komagata, K

    1995-05-01

    Traditional fermented foods (fish, meat and vegetable products), produced by many different processes, are eaten in many parts of Thailand. Lactic acid bacteria are responsible for the souring and ripening of these foods. Homofermentative strains of Lactobacillus pentosus, L. plantarum and Pediococcus pentosaceus are dominant in foods with low salt concentrations whereas P. halophilus strains are present in foods containing high salt. Strains of Lactobacillus sake, other Lactobacillus spp., P. acidilactici and P. urinaeequi are frequently found. Heterofermentative strains of L. brevis, L. confusus, L. fermentum, L. vaccinostercus, other Lactobacillus spp., and of Leuconostoc spp. are distributed as minor bacteria and strains of Staphylococcus, Enterococcus and Halobacterium are occasionally isolated. PMID:24414643

  8. Hepatoprotective effect of lactic acid bacteria, inhibitors of ?-glucuronidase production against intestinal microflora

    Microsoft Academic Search

    Song-Yi Han; Chul-Sung Huh; Young-Tae Ahn; Kwang-Sei Lim; Young-Jin Baek; Dong-Hyun Kim

    2005-01-01

    The hepatoprotective activity of lactic acid bacteria (Lactobacillus brevis HY7401,Lactobacillus acidophilus CSG andBifidobacterium longum HY8001), which inhibited ?-glucuronidase productivity of intestinal microflora, ont-BHP- or CCI4-induced hepatotoxicity of mice were evaluated. These oral administration of lactic acid bacteria lowered ?-glucuronidase\\u000a production of intestinal microflora as well asEscherichia coli HGU-3. When lactic acid bacteria at a dose of 0.5 or 2 g

  9. Characterization of lactic acid bacteria isolated from Algerian arid zone raw goats' milk

    Microsoft Academic Search

    Bettache GUESSAS; Mebrouk KIHAL

    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, Lactobacillus. The representative species of the total cocci were Lactococcus sp. (76.16%),

  10. Fermentation of high-protein plant biomass by introduction of lactic acid bacteria

    Microsoft Academic Search

    R. A. Shurkhno; R. G. Gareev; A. G. Abul’khanov; Sh. Z. Validov; A. M. Boronin; R. P. Naumova

    2005-01-01

    Lactic acid bacteria displaying increased ability to produce lactic acid, medium proteolytic activity, and tolerance to osmotic stress were isolated under selective conditions from phyllosphere and rhizosphere of registered and raised cultivars of legumes. Lactic fermentation of poorly ensilable leguminous plants (red clover and Caucasian goat’s rue) was performed by introduction of rifampin-resistant homofermenting representatives of the genus Lactobacillus (selected

  11. Recombinant lactic acid bacteria as mucosal biotherapeutic agents.

    PubMed

    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. PMID:21665301

  12. Production, recovery and purification of bacteriocins from lactic acid bacteria

    Microsoft Academic Search

    E. Parente; A. Ricciardi

    1999-01-01

    Bacteriocins produced by lactic acid bacteria are a heterogeneous group of peptide inhibitors which include lantibiotics\\u000a (class I, e.g. nisin), small heat-stable peptides (class II, e.g. pediocin AcH\\/PA1) and large heat-labile proteins (class\\u000a III, e.g. helveticin J). Many bacteriocins belonging to the first two groups can be successfully used to inhibit undesirable\\u000a microorganisms in foods, but only nisin is produced

  13. Production of probiotic cabbage juice by lactic acid bacteria.

    PubMed

    Yoon, Kyung Young; Woodams, Edward E; Hang, Yong D

    2006-08-01

    Research was undertaken to determine the suitability of cabbage as a raw material for production of probiotic cabbage juice by lactic acid bacteria (Lactobacillus plantarum C3, Lactobacillus casei A4, and Lactobacillus delbrueckii D7). Cabbage juice was inoculated with a 24-h-old lactic culture and incubated at 30 degrees C. Changes in pH, acidity, sugar content, and viable cell counts during fermentation under controlled conditions were monitored. L. casei, L. delbrueckii, and L. plantarum grew well on cabbage juice and reached nearly 10x10(8) CFU/mL after 48 h of fermentation at 30 degrees C. L. casei, however, produced a smaller amount of titratable acidity expressed as lactic acid than L. delbrueckii or L. plantarum. After 4 weeks of cold storage at 4 degrees C, the viable cell counts of L. plantarum and L. delbrueckii were still 4.1x10(7) and 4.5x10(5) mL(-1), respectively. L. casei did not survive the low pH and high acidity conditions in fermented cabbage juice and lost cell viability completely after 2 weeks of cold storage at 4 degrees C. Fermented cabbage juice could serve as a healthy beverage for vegetarians and lactose-allergic consumers. PMID:16125381

  14. Inhibition of citrus fungal pathogens by using lactic acid bacteria.

    PubMed

    Gerez, C L; Carbajo, M S; Rollán, G; Torres Leal, G; Font de Valdez, G

    2010-08-01

    The effect of lactic acid bacteria (LAB) on pathogenic fungi was evaluated and the metabolites involved in the antifungal effect were characterized. Penicillium digitatum (INTA 1 to INTA 7) and Geotrichum citri-aurantii (INTA 8) isolated from decayed lemon from commercial packinghouses were treated with imazalil and guazatine to obtain strains resistant to these fungicides. The most resistant strains (4 fungal strains) were selected for evaluating the antifungal activity of 33 LAB strains, among which only 8 strains gave positive results. The antifungal activity of these LAB strains was related to the production of lactic acid, acetic acid, and phenyllactic acid (PLA). A central composite design and the response surface methodology were used to evaluate the inhibitory effect of the organic acids produced by the LAB cultures. The antifungal activity of lactic acid was directly related to its concentration; however, acetic acid and PLA showed a peak of activity at 52.5 and 0.8 mM, respectively, with inhibition rates similar to those obtained with Serenade((R)) (3.0 ppm) imazalil (50 ppm) and guazatine (50 ppm). Beyond the peak of activity, a reduction in effectiveness of both acetic acid and PLA was observed. Comparing the inhibition rate of the organic acids, PLA was about 66- and 600-fold more effective than acetic acid and lactic acid, respectively. This study presents evidences on the antifungal effect of selected LAB strains and their end products. Studies are currently being undertaken to evaluate the effectiveness in preventing postharvest diseases on citrus fruits. PMID:20722936

  15. Development of Mucosal Vaccines Based on Lactic Acid Bacteria

    NASA Astrophysics Data System (ADS)

    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.

  16. Current taxonomy of phages infecting lactic acid bacteria

    PubMed Central

    Mahony, Jennifer; van Sinderen, Douwe

    2013-01-01

    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. PMID:24478767

  17. Comparative Studies of Class IIa Bacteriocins of Lactic Acid Bacteria

    PubMed Central

    Eijsink, Vincent G. H.; Skeie, Marianne; Middelhoven, P. Hans; Brurberg, May Bente; Nes, Ingolf F.

    1998-01-01

    Four class IIa bacteriocins (pediocin PA-1, enterocin A, sakacin P, and curvacin A) were purified to homogeneity and tested for activity toward a variety of indicator strains. Pediocin PA-1 and enterocin A inhibited more strains and had generally lower MICs than sakacin P and curvacin A. The antagonistic activity of pediocin-PA1 and enterocin A was much more sensitive to reduction of disulfide bonds than the antagonistic activity of sakacin P and curvacin A, suggesting that an extra disulfide bond that is present in the former two may contribute to their high levels of activity. The food pathogen Listeria monocytogenes was among the most sensitive indicator strains for all four bacteriocins. Enterocin A was most effective in inhibiting Listeria, having MICs in the range of 0.1 to 1 ng/ml. Sakacin P had the interesting property of being very active toward Listeria but not having concomitant high levels of activity toward lactic acid bacteria. Strains producing class IIa bacteriocins displayed various degrees of resistance toward noncognate class IIa bacteriocins; for the sakacin P producer, it was shown that this resistance is correlated with the expression of immunity genes. It is hypothesized that variation in the presence and/or expression of such immunity genes accounts in part for the remarkably large variation in bacteriocin sensitivity displayed by lactic acid bacteria. PMID:9726871

  18. Comparative functional genomics of amino acid metabolism of lactic acid bacteria

    Microsoft Academic Search

    M. I. Pastink

    2009-01-01

    The amino acid metabolism of lactic acid bacteria used as starters in industrial fermentations has profound effects on the quality of the fermented foods. The work described in this PhD thesis was initiated to use genomics technologies and a comparative approach to link the gene content of some well-known lactic acid bacteria to flavor formation and to increase our general

  19. Aerobic Denitrifying Bacteria That Produce Low Levels of Nitrous Oxide

    PubMed Central

    Takaya, Naoki; Catalan-Sakairi, Maria Antonina B.; Sakaguchi, Yasushi; Kato, Isao; Zhou, Zhemin; Shoun, Hirofumi

    2003-01-01

    Most denitrifiers produce nitrous oxide (N2O) instead of dinitrogen (N2) under aerobic conditions. We isolated and characterized novel aerobic denitrifiers that produce low levels of N2O under aerobic conditions. We monitored the denitrification activities of two of the isolates, strains TR2 and K50, in batch and continuous cultures. Both strains reduced nitrate (NO3?) to N2 at rates of 0.9 and 0.03 ?mol min?1 unit of optical density at 540 nm?1 at dissolved oxygen (O2) (DO) concentrations of 39 and 38 ?mol liter?1, respectively. At the same DO level, the typical denitrifier Pseudomonas stutzeri and the previously described aerobic denitrifier Paracoccus denitrificans did not produce N2 but evolved more than 10-fold more N2O than strains TR2 and K50 evolved. The isolates denitrified NO3? with concomitant consumption of O2. These results indicated that strains TR2 and K50 are aerobic denitrifiers. These two isolates were taxonomically placed in the ? subclass of the class Proteobacteria and were identified as P. stutzeri TR2 and Pseudomonas sp. strain K50. These strains should be useful for future investigations of the mechanisms of denitrifying bacteria that regulate N2O emission, the single-stage process for nitrogen removal, and microbial N2O emission into the ecosystem. PMID:12788710

  20. Biodegradation of Asphalt Cement-20 by Aerobic Bacteria

    PubMed Central

    Pendrys, John P.

    1989-01-01

    Seven gram-negative, aerobic bacteria were isolated from a mixed culture enriched for asphalt-degrading bacteria. The predominant genera of these isolates were Pseudomonas, Acinetobacter, Alcaligenes, Flavimonas, and Flavobacterium. The mixed culture preferentially degraded the saturate and naphthene aromatic fractions of asphalt cement-20. A residue remained on the surface which was resistant to biodegradation and protected the underlying asphalt from biodegradation. The most potent asphalt-degrading bacterium, Acinetobacter calcoaceticus NAV2, excretes an emulsifier which is capable of emulsifying the saturate and naphthene aromatic fractions of asphalt cement-20. This emulsifier is not denatured by phenol. PMID:16347928

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

    Microsoft Academic Search

    Lucila Saavedra; Fernando Sesma

    2011-01-01

    \\u000a The search for new antimicrobial peptides produced by lactic acid ­bacteria and other Gram-positive microorganisms has become\\u000a an interesting field of research in the past decades. The fact that bacteriocins are active against numerous foodborne and\\u000a human pathogens, are produced by generally regarded as safe (GRAS) microorganisms, and are readily degraded by proteolytic\\u000a host systems makes them attractive candidates for

  2. Metabolite Profiles of Lactic Acid Bacteria in Grass Silage?

    PubMed Central

    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-hydroxybenzoic acid, (trans, trans)-3,4-dihydroxycyclohexane-1-carboxylic acid, p-hydrocoumaric acid, vanillic acid, azelaic acid, hydroferulic acid, p-coumaric acid, hydrocaffeic acid, ferulic acid, and caffeic acid. Among these metabolites, the antifungal compounds 3-phenyllactic acid and 3-hydroxydecanoic acid were previously isolated in our laboratory from liquid cultures of the same LAB strains by bioassay-guided fractionation. It was concluded that other metabolites, e.g., p-hydrocoumaric acid, hydroferulic acid, and p-coumaric acid, were released from the grass by the added LAB strains. The antifungal activities of the identified metabolites in 100 mM lactic acid were investigated. The MICs against Pichia anomala, Penicillium roqueforti, and Aspergillus fumigatus were determined, and 3-hydroxydecanoic acid showed the lowest MIC (0.1 mg ml?1 for two of the three test organisms). PMID:17616609

  3. Biodiversity of lactic acid bacteria in Romanian dairy products.

    PubMed

    Zamfir, Medana; Vancanneyt, Marc; Makras, Lefteris; Vaningelgem, Frederik; Lefebvre, Karen; Pot, Bruno; Swings, Jean; De Vuyst, Luc

    2006-09-01

    Traditionally fermented dairy products are still a very important part of the daily food in Romania, especially for people living in the countryside. To study the biodiversity of lactic acid bacterium strains of these products, 110 samples (raw and fermented milk, sour cream, and cheese) were collected from farm houses, monasteries, and local markets throughout Romania. Lactic acid bacteria (LAB) were isolated using six different cultivation conditions. All 599 isolates were tested for their Gram reaction, catalase activity, and morphology. A rep-PCR fingerprinting technique with the (GTG)5 primer and, in some cases SDS-PAGE of total cell proteins and 16S rRNA gene sequencing were used to cluster and/or identify the LAB. The biodiversity of the isolated strains was correlated with the type of product and/or technology applied. The most frequent LAB found in Romanian raw milk and fermented dairy products were Lactococcus lactis, Leuconostoc spp., and Enterococcus spp. Among the latter, a new species E. saccharominimus was found. PMID:16919730

  4. Spray-drying of bacteriocin-producing lactic acid bacteria.

    PubMed

    Mauriello, G; Aponte, M; Andolfi, R; Moschetti, G; Villani, F

    1999-07-01

    Cell survival, cellular damage, and antagonistic activity were investigated after spray-drying of four bacteriocin-producing strains of lactic acid bacteria: Lactococcus lactis subsp. lactis 140, isolated from natural whey culture and producing a narrow-inhibitory spectrum bacteriocin); L. lactis subsp. lactis G35, isolated from pizza dough and producing nisin; Lactobacillus curvatus 32Y and Lactobacillus sp. 8Z, isolated from dry sausages. Trials were performed with bacteria suspended in skimmed milk or directly grown in whey. Three air temperatures at the inlet of the drier (160, 180, and 200 degrees C) and three flow rates (10, 13, and 17 ml/min) were assayed. Cell viability and bacteriocin activity of the dried materials were determined immediately after the process and after 5, 15, 30, and 60 days of storage at 4 degrees C. There was no significant difference between the two feeding suspensions in cell survival, always decreasing with the increase of inlet-air temperature. No loss of bacteriocin activity was detected in reconstituted powders, nor was any loss of ability to produce bacteriocin found after drying. Investigations of sensitivity to NaCl revealed only temporary damage to dried bacteria. During storage for 2 months at 4 degrees C, all samples, but mainly the lactococcal strains, displayed a gradual decrease in cell survival. Bacteriocin activity remained at the same level, allowing powders to be considered as effective biopreservatives. PMID:10419271

  5. Cell wall structure and function in lactic acid bacteria

    PubMed Central

    2014-01-01

    The cell wall of Gram-positive bacteria is a complex assemblage of glycopolymers and proteins. It consists of a thick peptidoglycan sacculus that surrounds the cytoplasmic membrane and that is decorated with teichoic acids, polysaccharides, and proteins. It plays a major role in bacterial physiology since it maintains cell shape and integrity during growth and division; in addition, it acts as the interface between the bacterium and its environment. Lactic acid bacteria (LAB) are traditionally and widely used to ferment food, and they are also the subject of more and more research because of their potential health-related benefits. It is now recognized that understanding the composition, structure, and properties of LAB cell walls is a crucial part of developing technological and health applications using these bacteria. In this review, we examine the different components of the Gram-positive cell wall: peptidoglycan, teichoic acids, polysaccharides, and proteins. We present recent findings regarding the structure and function of these complex compounds, results that have emerged thanks to the tandem development of structural analysis and whole genome sequencing. Although general structures and biosynthesis pathways are conserved among Gram-positive bacteria, studies have revealed that LAB cell walls demonstrate unique properties; these studies have yielded some notable, fundamental, and novel findings. Given the potential of this research to contribute to future applied strategies, in our discussion of the role played by cell wall components in LAB physiology, we pay special attention to the mechanisms controlling bacterial autolysis, bacterial sensitivity to bacteriophages and the mechanisms underlying interactions between probiotic bacteria and their hosts. PMID:25186919

  6. Cell wall structure and function in lactic acid bacteria.

    PubMed

    Chapot-Chartier, Marie-Pierre; Kulakauskas, Saulius

    2014-08-29

    The cell wall of Gram-positive bacteria is a complex assemblage of glycopolymers and proteins. It consists of a thick peptidoglycan sacculus that surrounds the cytoplasmic membrane and that is decorated with teichoic acids, polysaccharides, and proteins. It plays a major role in bacterial physiology since it maintains cell shape and integrity during growth and division; in addition, it acts as the interface between the bacterium and its environment. Lactic acid bacteria (LAB) are traditionally and widely used to ferment food, and they are also the subject of more and more research because of their potential health-related benefits. It is now recognized that understanding the composition, structure, and properties of LAB cell walls is a crucial part of developing technological and health applications using these bacteria. In this review, we examine the different components of the Gram-positive cell wall: peptidoglycan, teichoic acids, polysaccharides, and proteins. We present recent findings regarding the structure and function of these complex compounds, results that have emerged thanks to the tandem development of structural analysis and whole genome sequencing. Although general structures and biosynthesis pathways are conserved among Gram-positive bacteria, studies have revealed that LAB cell walls demonstrate unique properties; these studies have yielded some notable, fundamental, and novel findings. Given the potential of this research to contribute to future applied strategies, in our discussion of the role played by cell wall components in LAB physiology, we pay special attention to the mechanisms controlling bacterial autolysis, bacterial sensitivity to bacteriophages and the mechanisms underlying interactions between probiotic bacteria and their hosts. PMID:25186919

  7. Lactic acid bacteria convert human fibroblasts to multipotent cells.

    PubMed

    Ohta, Kunimasa; Kawano, Rie; Ito, Naofumi

    2012-01-01

    The human gastrointestinal tract is colonized by a vast community of symbionts and commensals. Lactic acid bacteria (LAB) form a group of related, low-GC-content, gram-positive bacteria that are considered to offer a number of probiotic benefits to general health. While the role of LAB in gastrointestinal microecology has been the subject of extensive study, little is known about how commensal prokaryotic organisms directly influence eukaryotic cells. Here, we demonstrate the generation of multipotential cells from adult human dermal fibroblast cells by incorporating LAB. LAB-incorporated cell clusters are similar to embryoid bodies derived from embryonic stem cells and can differentiate into endodermal, mesodermal, and ectodermal cells in vivo and in vitro. LAB-incorporated cell clusters express a set of genes associated with multipotency, and microarray analysis indicates a remarkable increase of NANOG, a multipotency marker, and a notable decrease in HOX gene expression in LAB-incorporated cells. During the cell culture, the LAB-incorporated cell clusters stop cell division and start to express early senescence markers without cell death. Thus, LAB-incorporated cell clusters have potentially wide-ranging implications for cell generation, reprogramming, and cell-based therapy. PMID:23300571

  8. Evaluation of Immunomodulatory Effects of Lactic Acid Bacteria in Turbot (Scophthalmus maximus)

    Microsoft Academic Search

    L. Villamil; C. Tafalla; A. Figueras; B. Novoa

    2002-01-01

    In the present work, the effects of several lactic acid bacteria on the immune response of turbot (Scophthal- mus maximus) macrophages have been studied both in vitro and in vivo. Out of six lactic acid bacterial strains tested, only heat-killed Lactococcus lactis significantly increased the turbot head kidney macrophage chemilu- minescent (CL) response after 24 h of incubation. Nitric oxide

  9. The Benefits of Lactic Acid Bacteria in Yogurt on the Gastrointestinal Function and Health

    Microsoft Academic Search

    Ayman Suliman Mazahreh; Omer Turki Mamdoh Ershidat

    2009-01-01

    2 Abstract: The nutritional value of yogurt and Lactic Acid-producing Bacteria (LAB) on the gastrointestinal health and function, have been investigated in this study. Both Lactobacillus bulgaricus and Streptococcus thermophilus (LAB) species, contribute to the formation of yogurt as a result of anaerobic fermentation of lactic acid in the milk. The present study focuses on the effect of yogurt consumption

  10. Bacillus spp. produce antibacterial activities against lactic acid bacteria that contaminate fuel ethanol plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. Canine intestinal lactic acid bacteria agglutinated with concanavalin A.

    PubMed

    Kim, So-Young; Ogawa, Yasuki; Adachi, Yoshikazu

    2006-12-01

    Twenty-six out of 46 representative lactic acid bacteria (LAB) that we isolated from 36 dogs in a previous study were agglutinated by concanavalin A (ConA) at a concentration of 0.1563 mg/ml, while isolates did not agglutinate without the addition of ConA. Amongst the isolates, L. reuteri, L. mucosae, and E. canintestini agglutinated strongly, while L. gallinarum, L. kitasatonis, L. acidophilus, L. saerimneri, B. animalis ssp. animalis, P. acidilactici, and E. hirae did not agglutinate. ConA-agglutination of LAB was specifically inhibited by D-glucose, D-galactose, and D-mannose at a concentration of 1.563 mg/ml. Among the sugars, ConA-agglutination was strongly inhibited by D-mannose, while the inhibition level by D-glucose and D-galactose were lower than that of D-mannose. ConA- agglutination of all the LAB isolates was inhibited by D-mannose, except for L. reuteri (one species) and L. mucosae (two species). ConA-agglutination of Bifidobacterium spp. was inhibited by only D-mannose. Based on our results, ConA-agglutination of LAB seems to be strain-specific, but not species-specific. PMID:17213708

  12. Antihepatocarcinoma activity of lactic acid bacteria fermented Panax notoginseng.

    PubMed

    Lin, Yu-Wei; Mou, Yu-Chen; Su, Chen-Chiang; Chiang, Been-Huang

    2010-08-11

    Panax notoginseng was used as the medium for lactic acid bacteria fermentation to manufacture product with antihepatocarcinoma activity. The fermentation broth prepared in a 250 mL Erlenmeyer flask was found to possess antiproliferation activity against hepatoma Hep3B cells. At the dosage of 500 microg/mL, the viability of hepatoma Hep3B cells was approximately 2.2%. When the fermentation was scaled up to a 6.6 L fermenter, it was found that the fermentation broth produced at 37 degrees C for 2 days showed the highest antihepatoma activity. Animal study revealed that when Hep3B implanted SCID mice were treated with 1000 mg/kg BW/day of the fermentation broth, tumor volume and tumor weight were reduced approximately 60% as compared to the negative control group. HPLC analyses showed that saponins in P. notoginseng including notoginsenoside R(1) and ginsenosides Rg(1), Rb(1), Rd, and Rh(4) decreased, but ginsenosides Rh(1) and Rg(3) increased during fermentation. LC-MS/MS revealed that the minor saponins ginsenoside F(1), protopanaxatriol, and notoginseng R(2) also exist in the fermentation product. It appears that ginsenoside Rg(3), ginsenoside Rh(1), and protopanaxatriol are possibly responsible for the enhanced antihepatocarcinoma activity of the P. notoginseng fermentation broth. PMID:20681639

  13. Mucosal vaccination and therapy with genetically modified lactic acid bacteria.

    PubMed

    Wells, Jerry

    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 afford protection against infectious challenges. To be effective via oral administration, frequent dosing over several weeks is required but new targeting and adjuvant strategies have clearly demonstrated the potential to increase the immunogenicity and protective immunity of LAB vaccines. Oral administration of Lactococcus lactis has been shown to induce antigen-specific oral tolerance (OT) to secreted recombinant antigens. LAB delivery is more efficient at inducing OT than the purified antigen, thus avoiding the need for purification of large quantities of antigen. This approach holds promise for new therapeutic interventions in allergies and antigen-induced autoimmune diseases. Several clinical and research reports demonstrate considerable progress in the application of genetically modified L. lactis for the treatment of inflammatory bowel disease (IBD). New medical targets are on the horizon, and the approval by several health authorities and biosafety committees of a containment system for a genetically modified L. lactis that secretes Il-10 should pave the way for new LAB delivery applications in the future. PMID:22129390

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

    PubMed Central

    Vasama, Mari; Kumar, Himanshu; Salminen, Seppo; Haskard, Carolyn A.

    2014-01-01

    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. PMID:25046082

  15. Antagonism of Helicobacter pylori by bacteriocins of lactic acid bacteria.

    PubMed

    Kim, Tae-Seok; Hur, Ji-Woon; Yu, Myeong-Ae; Cheigh, Chan-Ick; Kim, Kyung-Nam; Hwang, Jae-Kwan; Pyun, Yu-Ryang

    2003-01-01

    Antimicrobial activity of seven bacteriocins produced by lactic acid bacteria against Helicobacter pylori strains (ATCC 43504, Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH [DSM] 4867, DSM 9691, and DSM 10242) was investigated in vitro using a broth microdilution assay. The bacteriocins chosen for the study were nisin A; lacticins A164, BH5, JW3, and NK24; pediocin PO2; and leucocin K. Antimicrobial activity of the bacteriocins varied among the H. pylori strains tested, of which strain ATCC 43504 was the most tolerant. Among the bacteriocins tested, lacticins A164 and BH5 produced by Lactococcus lactis subsp. lactis A164 and L. lactis BH5, respectively, showed the strongest antibacterial activity against H. pylori strains. MICs of the lacticins against H. pylori strains, when assessed by the critical dilution micromethod, ranged from 0.097 to 0.390 mg/liter (DSM strains) or from 12.5 to 25 mg/liter (ATCC 43504), supporting the strain-dependent sensitivity of the pathogen. Pediocin PO2 was less active than the lacticins against four strains of H. pylori, and leucocin K was the least active peptide, with no inhibition toward H. pylori ATCC 43504. Anti-Helicobacter activity of lacticin A164 was dependent on initial inoculum size as well as concentration of the bacteriocin added. PMID:12540174

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

    PubMed

    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. PMID:25763303

  17. [Identification of industrial strains of lactic acid bacteria by methods of molecular genetic typing].

    PubMed

    Botina, S G; Tsygankov, Iu D; Sukhodolets, V V

    2006-12-01

    Various methods currently used in microbiology for determining taxonomic state of bacteria are discussed. The main focus is aimed at identifying and gene typing of lactic acid bacteria, used as starter cultures for industrial process of production of sour milk products, meat products, and probiotics. PMID:17326382

  18. Study of the Possible Mechanisms Involved in the Mucosal Immune System Activation by Lactic Acid Bacteria

    Microsoft Academic Search

    G. Perdigón; E. Vintiñi; S. Alvarez; M. Medina; M. Medici

    1999-01-01

    The induction of a mucosal immune response is not easy due to the development of oral tolerance, but under some conditions, bacteria can activate this im- mune system. Antigens administered orally can inter- act with M cells of Peyer's patches or bind to the epithelial cells. We have demonstrated that certain lactic acid bacteria are able to induce specific secre-

  19. Comparative genomics of lactic acid bacteria reveals a niche-specific gene set

    Microsoft Academic Search

    Orla O'Sullivan; John O'Callaghan; Amaia Sangrador-Vegas; Olivia McAuliffe; Lydia Slattery; Pawel Kaleta; Michael Callanan; Gerald F Fitzgerald; R Paul Ross; Tom Beresford

    2009-01-01

    BACKGROUND: The recently sequenced genome of Lactobacillus helveticus DPC4571 1 revealed a dairy organism with significant homology (75% of genes are homologous) to a probiotic bacteria Lb. acidophilus NCFM 2. This led us to hypothesise that a group of genes could be determined which could define an organism's niche. RESULTS: Taking 11 fully sequenced lactic acid bacteria (LAB) as our

  20. Short communication Metatranscriptome analysis of lactic acid bacteria during kimchi fermentation with

    E-print Network

    Bae, Jin-Woo

    Short communication Metatranscriptome analysis of lactic acid bacteria during kimchi fermentation microbial diversity and biological activity during the fermentation of kimchi, a traditional Korean. Metagenomic analysis revealed 23 LAB related to kimchi fermentation [defined as bacteria with more than a 1

  1. Strong Synergy between a Eukaryotic Antimicrobial Peptide and Bacteriocins from Lactic Acid Bacteria

    Microsoft Academic Search

    Torben Luders; Gunn Alice Birkemo; Gunnar Fimland; Jon Nissen-Meyer; Ingolf F. Nes

    2003-01-01

    The antimicrobial effect obtained upon combining the prokaryotic antimicrobial peptides (AMPs; more commonly referred to as bacteriocins) pediocin PA-1, sakacin P, and curvacin A (all produced by lactic acid bacteria (LAB)) with the eukaryotic AMP pleurocidin (from fish) has been investigated. The three LAB AMPs alone were active against gram-positive Listeria ivanovii bacteria at nanomolar concentrations, whereas they were inactive

  2. 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.

    PubMed

    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). PMID:26082325

  3. Cancer Preventive Potential of Kimchi Lactic Acid Bacteria (Weissella cibaria, Lactobacillus plantarum)

    PubMed Central

    Kwak, Shin-Hye; Cho, Young-Mi; Noh, Geon-Min; Om, Ae-Son

    2014-01-01

    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. PMID:25574459

  4. Cancer Preventive Potential of Kimchi Lactic Acid Bacteria (Weissella cibaria, Lactobacillus plantarum).

    PubMed

    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. PMID:25574459

  5. Plasmids from Food Lactic Acid Bacteria: Diversity, Similarity, and New Developments

    PubMed Central

    Cui, Yanhua; Hu, Tong; Qu, Xiaojun; Zhang, Lanwei; Ding, Zhongqing; Dong, Aijun

    2015-01-01

    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. PMID:26068451

  6. Modulation by lactic-acid bacteria of the intestinal ecosystem and plasma cholesterol in rabbits fed a casein diet

    Microsoft Academic Search

    Enrica Canzi; Raffaella Zanchi; Paola Camaschella; Alberto Cresci; Gian Franco Greppi; Carla Orpianesi; Monica Serrantoni; Annamaria Ferrari

    2000-01-01

    The effect of lactic acid bacteria on the serum cholesterol levels and the cecal microflora in rabbits fed dietary casein has been examined. A control group was fed a soybean protein diet, three other groups a casein diet; two of tho groups given casein were also given lyophilised resting cells of lactic acid bacteria: Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus

  7. Characterization of lactic acid bacteria and other gut bacteria in pigs by a macroarraying method.

    PubMed

    Thanantong, Narut; Edwards, Sandra; Sparagano, Olivier A E

    2006-10-01

    Lactic acid bacteria (LAB) consist of many genera, Gram-positive, and nonspore-forming micro-organisms; some members being used as probiotics while some others have negative effects on pig health. Bacterial species in the gastrointestinal tract can produce antibacterial substances, reduce serum cholesterol in their host, or can be responsible for growth reduction, diarrhea, and intestinal epithelial damage. It is therefore important for the pig industry to evaluate the impact of food and farm management on the presence of "good" or "bad" bacteria and the risk for consumers. This articles focuses on the molecular identification of gut microflora species following different diets given to pigs in UK and correlating the data on growth, health, and welfare. First of all, pig feces were individually collected from sows before and after farrowing and also from piglets before and after weaning over several months. Bacteria colonies were grown on MRS agar plates from feces and DNA was extracted (QIAamp DNA stool kit) and amplified using 16S rDNA (27f and 519r) primers. DNA sequencing and sequence alignment allowed us to identify species-specific zones, which were used as probes in a macroarray system also known as reverse line blot hybridization. Some probes were found to be species specific for the following species: Lactobacillus acidophilus, L. animalis, L. gallinarum, L. kitasanotis, L salivarius, Streptococcus alactolyticus, S. hyointestinalis, and Sarcina ventriculi. Actual studies are now focusing on the impact of diets of the microflora in different gut parts and at different stages of the animal's life. PMID:17135526

  8. Antibacterial Activity of Some Lactic Acid Bacteria Isolated from an Algerian Dairy Product

    PubMed Central

    Mezaini, Abdelkader; Chihib, Nour-Eddine; Dilmi Bouras, Abdelkader; Nedjar-Arroume, Naima; Hornez, Jean Pierre

    2009-01-01

    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 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. PMID:20041021

  9. Bacteriophages of lactic acid bacteria and their impact on milk fermentations

    PubMed Central

    2011-01-01

    Every biotechnology process that relies on the use of bacteria to make a product or to overproduce a molecule may, at some time, struggle with the presence of virulent phages. For example, phages are the primary cause of fermentation failure in the milk transformation industry. This review focuses on the recent scientific advances in the field of lactic acid bacteria phage research. Three specific topics, namely, the sources of contamination, the detection methods and the control procedures will be discussed. PMID:21995802

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

    Microsoft Academic Search

    Margreet I. Pastink; Bas Teusink; Pascal Hols; Sanne Visser; Vos de W. M; Jeroen Hugenholtz

    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 metabolic model of S. thermophilus, the metabolic differences between the three bacteria were visualized by direct projection on a metabolic map. The

  11. The role of lactic acid bacteria in colon cancer prevention: mechanistic considerations

    Microsoft Academic Search

    Kazuhiro Hirayama; Joseph Rafter

    1999-01-01

    Colorectal cancer is one of the most important causes of cancer morbidity and mortality in Western countries. While a myriad of healthful effects have been attributed to the probiotic lactic acid bacteria, perhaps the most controversial remains that of anticancer activity. It should be pointed out already at this point that there is no direct experimental evidence for cancer suppression

  12. EXTERNAL TREATMENT OF BROILER CHICKENS WITH LACTIC ACID BACTERIA BEFORE SLAUGHTER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lactic-acid-producing bacterial cultures were applied to the skin of live broilers 24 hours before slaughter to determine whether inoculation with the cultures could affect the numbers of bacteria that are normally found on the skin of processed broiler carcasses. The cultures contained 10,000 to 1...

  13. Technological characterization of lactic acid bacteria isolated from Armada cheese (a Spanish goats’ milk cheese)

    Microsoft Academic Search

    M. A Herreros; J. M Fresno; M. J González Prieto; M. E Tornadijo

    2003-01-01

    Thirty-one strains of lactic acid bacteria (LAB) isolated from Armada cheese, Sobado variety, (eight strains of Lactococcus lactis subsp. lactis, four strains of Lactococcus lactis subsp. cremoris, two strains of L. lactis subsp. lactis biovar. diacetylactis, two strains of Leuconostoc mesenteroides subsp. mesenteroides, two strains of Leuconostoc mesenteroides subsp. dextranicum, five strains of Lactobacillus plantarum, six strains of Lactobacillus casei

  14. Potential of bacteriocin-producing lactic acid bacteria for improvements in food safety and quality

    Microsoft Academic Search

    L O’Sullivan; R. P Ross; C Hill

    2002-01-01

    Lactic acid bacteria (LAB) have been used for centuries in the fermentation of a variety of dairy products. The preservative ability of LAB in foods is attributed to the production of anti-microbial metabolites including organic acids and bacteriocins. Bacteriocins generally exert their anti-microbial action by interfering with the cell wall or the membrane of target organisms, either by inhibiting cell

  15. Survival of Lactic Acid Bacteria in the Human Stomach and Adhesion to Intestinal Cells

    Microsoft Academic Search

    P. L. Conway; S. L. Gorbach; B. R. Goldin

    1987-01-01

    The survival of four strains of lactic acid bacteria in human gastric juice, in vivo and in vitro, and in buffered saline, pH 1 to 5, has been investigated. The strains studied include two Lactobacillus acidophilus strains, Lactobacillus bul- garicus, and Streptococcus thermophilus. In addition, the adhesion of these strains to freshly collected human and pig small intestinal cells and

  16. Resected Human Colonic Tissue: New Model for Characterizing Adhesion of Lactic Acid Bacteria

    Microsoft Academic Search

    Arthur C. Ouwehand; Seppo Salminen; Satu Tolkko; Peter Roberts; Jari Ovaska; Eeva Salminen

    2002-01-01

    Lactic acid bacteria (LAB) are commonly used to balance aberrant intestinal microflora and manage microflora dysfunc- tions (5, 6). Adhesion to the intestinal mucosa is considered important for beneficial health effects (2). In order to assess the adhesive abilities of LAB, in vitro adhesion models have been developed. The most widely used models are tissue cul- ture cells (1, 13)

  17. An evaluation of chelex-based DNA purification protocols for the typing of lactic acid bacteria

    Microsoft Academic Search

    Giorgio Giraffa; Lia Rossetti; Erasmo Neviani

    2000-01-01

    An easy and rapid protocol to extract DNA to be used as template for polymerase chain reaction (PCR) fingerprinting experiments from cultivable lactic acid bacteria (LAB) is proposed. Different procedures for rapid extraction of DNA by chelex (iminodiacetid acid) ionic resin were compared. Factors affecting the quality and reproducibility of PCR fingerprinting profiles were also investigated. Two out of three

  18. Characterization of probiotic properties of lactic acid bacteria isolated from intestinal microbiota of fish

    Microsoft Academic Search

    José L. Balcázar; Daniel Vendrell; Ignacio de Blas; Imanol Ruiz-Zarzuela; José L. Muzquiz; Olivia Girones

    2008-01-01

    The aim of this study was to evaluate the ability of three lactic acid bacteria (LAB) isolated from fish, Lactococcus lactis CLFP 101, Lactobacillus plantarum CLFP 238, and Lactobacillus fermentum CLFP 242 to inhibit adhesion of several fish pathogens (Aeromonas hydrophila, Aeromonas salmonicida, Yersinia ruckeri and Vibrio anguillarum) to host intestinal mucus under in vitro conditions. The results showed that

  19. Comparative study of lactic acid bacteria house flora isolated in different varieties of `chorizo'

    Microsoft Academic Search

    Eva M Santos; Consuelo González-Fernández; Isabel Jaime; Jordi Rovira

    1998-01-01

    A total of 516 strains of lactic acid bacteria isolated from `chorizo' (a Spanish dry fermented sausage) were identified. The `chorizo' was from three zones of Castilla and León in Spain: Burgos, Segovia and Salamanca. Two factories were chosen in each zone and the samples were taken at three stages of ripening. L. sake was the most predominant species present

  20. Effects of cultivation conditions on folate production by lactic acid bacteria

    Microsoft Academic Search

    Wilbert Sybesma; Marjo Starrenburg; Linda Tijsseling; Marcel H. N. Hoefnagel; Jeroen Hugenholtz

    2003-01-01

    A variety of lactic acid bacteria were screened for their ability to produce folate intracellularly and\\/or extracellularly. Lactococcus lactis, Streptococcus thermophilus, and Leuconostoc spp. all produced folate, while most Lactobacillus spp., with the exception of Lactobacillus plantarum, were not able to produce folate. Folate production was further investigated in L. lactis as a model organism for metabolic engineering and in

  1. Novel lactic acid bacteria inhibiting Paenibacillus larvae in honey bee larvae

    Microsoft Academic Search

    Eva Forsgren; Tobias C. Olofsson; Alejandra Váasquez; Ingemar Fries

    2010-01-01

    We evaluated the antagonistic effects of newly identified lactic acid bacteria (LAB) in the genera Lactobacillus and Bifidobacterium, originating from the honey stomach, on the honey bee pathogen, Paenibacillus larvae. We used inhibition assays on agar plates and honey bee larval bioassays to investigate the effects of honey bee LAB on P. larvae growth in vitro and on AFB infection

  2. Comparative genomics of enzymes in flavor-forming pathways from amino acids in lactic acid bacteria

    Microsoft Academic Search

    Mengjin Liu; Arjen Nauta; Christof Francke; Roland J. Siezen

    2008-01-01

    Lactic acid bacteria (LAB) have been widely used as starter or nonstarter cultures in the dairy industry for over a thousand years. They play an essential role in flavor formation during the fermentation of dairy products. Several metabolic routes can lead to the formation of flavor compounds when LAB are growing in milk. One of the main precursors for flavor

  3. Mucosal delivery of therapeutic and prophylactic molecules using lactic acid bacteria

    Microsoft Academic Search

    Jerry M. Wells; Annick Mercenier

    2008-01-01

    Studies of lactic acid bacteria (LAB) as delivery vehicles have focused mainly on the development of mucosal vaccines, with much effort being devoted to the generation of genetic tools for antigen expression in different bacterial locations. Subsequently, interleukins have been co-expressed with antigens in LAB to enhance the immune response that is raised against the antigen. LAB have also been

  4. SCREENING AND IDENTIFICATION OF LACTIC ACID BACTERIA PRODUCING ANTIMICROBIAL COMPOUNDS FROM PIG GASTROINTESTINAL TRACTS

    Microsoft Academic Search

    Nongpanga Khunajakr; Aporn Wongwicharn; Duangtip Moonmangmee; Sukon Tantipaiboonvut

    2008-01-01

    A total of 87 lactic acid bacteria were isolated from 15 samples of pig gastrointestinal tract. Antimicrobial activities of all isolates grown under oxygen-restricted conditions to eliminate the effect of hydrogen peroxide were tested against 5 pathogenic bacterial strains using agar well diffusion technique. Seventeen isolates exhibited antimicrobial activity against at least one indicator strain tested. Among the 17 isolates,

  5. Diversity of lactic acid bacteria associated with traditional fermented dairy products in Mongolia

    Microsoft Academic Search

    J. Yu; W. H. Wang; B. L. G. Menghe; M. T. Jiri; H. M. Wang; W. J. Liu; Q. H. Bao; Q. Lu; J. C. Zhang; F. Wang; H. Y. Xu; T. S. Sun; H. P. Zhang

    2011-01-01

    Spontaneous milk fermentation has a long history in Mongolia, and beneficial microorganisms have been handed down from one generation to the next for use in fermented dairy products. The objective of this study was to investigate the diversity of lactic acid bacteria (LAB) communities in fermented yak, mare, goat, and cow milk products by analyzing 189 samples collected from 13

  6. Screening of biogenic amine production by lactic acid bacteria isolated from grape must and wine

    Microsoft Academic Search

    M. Victoria Moreno-Arribas; M. Carmen Polo; Felisa Jorganes; Rosario Muñoz

    2003-01-01

    The potential to produce the biogenic amines tyramine, histamine and putrescine, was investigated for lactic acid bacteria (LAB) of various origin, including commercial malolactic starter cultures, type strains and 78 strains isolated from Spanish grape must and wine. The presence of biogenic amines in a decarboxylase synthetic broth was determined by reverse-phase high performance liquid chromatography (RP-HPLC). Tyramine was the

  7. Prevention of bread mould spoilage by using lactic acid bacteria with antifungal properties

    Microsoft Academic Search

    Carla Luciana Gerez; Maria Ines Torino; Graciela Rollán

    2009-01-01

    The ability of lactic acid bacteria (LAB) to inhibit Aspergillus, Fusarium, and Penicillium, the main contaminants in bread, was evaluated. Only four strains (Lactobacillus plantarum CRL 778, Lactobacillus reuteri CRL 1100, and Lactobacillus brevis CRL 772 and CRL 796) from 95 strains tested displayed antifungal activity. The major antifungal compounds were acetic and phenyllactic acids. The fermentation quotient (FQ=2.0) and

  8. Lactic Acid Bacteria as a Potential Source of Enzymes for Use in Vinification

    Microsoft Academic Search

    Angela Matthews; Antonio Grimaldi; Michelle Walker; Eveline Bartowsky; Paul Grbin; Vladimir Jiranek

    2004-01-01

    Two key groups of organisms are involved in the production of red, white, and sparkling wine. The yeasts, typically strains of Saccharomyces cerevisiae, carry out the primary or alcoholic fermentation, in which sugars are converted to ethanol and CO2. Lactic acid bacteria (LAB), especially Oenococcus oeni (formerly Leuconostoc oenos (51)), conduct the secondary or malolactic fermentation (MLF) of wine by

  9. Lactic Acid Bacteria in the Gut in Normal and Disordered States

    Microsoft Academic Search

    Seppo Salminen; Margaret Deighton

    1992-01-01

    The human gut flora is a complex and finely balanced ecosystem which plays an important protective role in humans. Although relatively stable, its composition may be altered in various disease states and by the administration of antimicrobial agents. Preparations containing viable lactic acid bacteria of human origin appear to have value in restoring normal microbial function and alleviating symptoms in

  10. ISOLATION AND IDENTIFICATION OF LACTIC ACID BACTERIA IN COCONUT TODDY (MNAZI)

    Microsoft Academic Search

    T. T. Kadere; P. M. Kutima

    2012-01-01

    Mnazi, like any other sugary plant sap can be processed into an alcoholic beverage through fermentation of the sugars present in the sap, yielding alcohol and carbon dioxide. It is sweet, dirty brown in color, containing 10-12% sugar, mainly sucrose (Okafor, 1975). The lactic acid bacteria isolated from mnazi were found to be Gram positive and catalase negative. A total

  11. Nonstarter Lactic Acid Bacteria and Aging Temperature Affect Calcium Lactate Crystallization in Cheddar Cheese

    Microsoft Academic Search

    Y.-E. Chou; C. G. Edwards; L. O. Luedecke; M. P. Bates; S. Clark

    2003-01-01

    The occurrence of unappetizing calcium lactate crys- tals in Cheddar cheese is a challenge and expense to manufacturers, and this research was designed to un- derstand their origin. It was hypothesized that non- starter lactic acid bacteria (NSLAB) affect calcium lac- tate crystallization (CLC) by producing D(?)-lactate. This study was designed to understand the effect of NSLAB growth and aging

  12. Effect of Lactic Acid Fermentation Bacteria on Plant Growth and Soil Humus Formation

    Microsoft Academic Search

    T. Higa; S. Kinjo

    A study was conducted to determine if lactic acid bacteria, when inoculated into soil amended with organic materials, could enhance decomposition and the release of plant nutrients, and increase soil humus formation. The addition of EM 4 to soil amended with fresh green grass increased the growth of cucumber over that of the unamended and fertilized controls, while woodchips appeared

  13. Biofilm Formation and Contamination of Cheese by Nonstarter Lactic Acid Bacteria in The Dairy Environment

    Microsoft Academic Search

    E. B. Somers; M. E. Johnson; A. C. L. Wong

    2001-01-01

    Defects in cheese, such as undesirable flavors, gas formation, or white surface haze from calcium lactate crystals, can result from growth of nonstarter lactic acid bacteria (NSLAB). The potential for biofilm forma- tion by NSLAB during cheese manufacturing, the effect of cleaning and sanitizing on the biofilm, and bacterial growth and formation of defects during ripening of the contaminated cheese

  14. The potential of lactic acid bacteria for the production of safe and wholesome food

    Microsoft Academic Search

    Walter P. Hammes; Petra S. Tichaczek

    1994-01-01

    By tradition lactic acid bacteria (LAB) are in- volved in the production of fermented foods. These con- stitute one quarter of our diet and are characterized by a safe history, certain beneficial health effects, and an ex- tended shelf life when compared with raw materials. The various fermenting substrates are habitats for specific LAB that differ in their metabolic potential.

  15. Predominant lactic acid bacteria in traditional fermented yak milk products in the Sichuan Province

    E-print Network

    Boyer, Edmond

    NOTE Predominant lactic acid bacteria in traditional fermented yak milk products in the Sichuan Abstract Yak milk products have been consumed for hundreds of years in the Sichuan province of China where-four samples of traditional yak milk products (kurut, qula cheese, raw milk, whey, and butter) were collected

  16. Probiotic properties of lactic-acid bacteria: plenty of scope for fundamental R & D

    Microsoft Academic Search

    Gerald W Tannock

    1997-01-01

    Probiotic products are marketed widely throughout the world. This is especially true of yogurts that contain strains of lactic-acid bacteria of intestinal origin. Consumption of these products is aimed at promoting the wellbeing of the consumer by impacting on the collection of microorganisms that normally inhabit the intestinal tract. The development of scientifically valid probiotics requires more detailed knowledge of

  17. Effect of grape polyphenols on lactic acid bacteria and bifidobacteria growth: Resistance and metabolism

    Microsoft Academic Search

    Raquel Tabasco; Fernando Sánchez-Patán; María Monagas; Begoña Bartolomé; M. Victoria Moreno-Arribas; Carmen Peláez; Teresa Requena

    2011-01-01

    Food polyphenols are able to selectively modify the growth of susceptible micro-organisms. This study describes the effect of a flavan-3-ol enriched grape seed extract (GSE) on the growth of several lactic acid bacteria (LAB) and bifidobacteria and the ability of the resistant strains to metabolize these compounds. Streptococcus thermophilus, Lactobacillus fermentum, Lactobacillus acidophilus and Lactobacillus vaginalis strains showed a remarkable

  18. Synthesis of  -Aminobutyric Acid by Lactic Acid Bacteria Isolated from a Variety of Italian Cheeses

    Microsoft Academic Search

    S. Siragusa; M. De Angelis; R. Di Cagno; C. G. Rizzello; R. Coda; M. Gobbetti

    2007-01-01

    The concentrations of -aminobutyric acid (GABA) in 22 Italian cheese varieties that differ in several technological traits markedly varied from 0.26 to 391 mg kg1. Presumptive lactic acid bacteria were isolated from each cheese variety (total of 440 isolates) and screened for the capacity to synthesize GABA. Only 61 isolates showed this activity and were identified by partial sequencing of

  19. Class IIa bacteriocins from lactic acid bacteria: Antibacterial activity and food preservation

    Microsoft Academic Search

    Saïd Ennahar; Kenji Sonomoto; Ayaaki Ishizaki

    1999-01-01

    In the last decade, a variety of ribosomally synthesized antimicrobial peptides, or bacteriocins, produced by lactic acid bacteria have been identified and characterized. As a result of these studies, insight has been gained into various fundamental aspects of biology and biochemistry such as bacteriocin processing and secretion, mechanisms of cell immunity, and structure-function relationships. In parallel, there has been a

  20. Potential of lactic acid bacteria isolated from specific natural niches in food production and preservation

    Microsoft Academic Search

    Ljubisa Topisirovic; Milan Kojic; Djordje Fira; Natasa Golic; Ivana Strahinic; Jelena Lozo

    2006-01-01

    Autochthonous strains of lactic acid bacteria (LAB) have been isolated from traditionally homemade cheeses collected from specific ecological localities across Serbia and Montenegro. Genetic and biochemical analysis of this LAB revealed that they produce bacteriocins, proteinases and exopolysaccharides. LAB produces a variety of antimicrobial substances with potential importance for food fermentation and preservation. Apart from the metabolic end products, some

  1. Organism-Adapted Specificity of the Allosteric Regulation of Pyruvate Kinase in Lactic Acid Bacteria

    PubMed Central

    Veith, Nadine; Feldman-Salit, Anna; Cojocaru, Vlad; Henrich, Stefan; Kummer, Ursula; Wade, Rebecca C.

    2013-01-01

    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 activation may reflect adaptation to different environments with different concentrations of activating compounds. The combined computational approach employed can readily be applied to other enzymes. PMID:23946717

  2. Sulfate reducing and methane producing bacteria in aerobic wastewater treatment systems

    Microsoft Academic Search

    P. N. Lens; M.-P. De Poorter; C. C. Cronenberg; W. H. Verstraete

    1995-01-01

    A selection of aerobic biofilm reactors and activated sludge plants were investigated for the presence of methane producing bacteria (MPB) and sulfate reducing bacteria (SRB). Detection tests showed that acetotrophic and hydrogenotrophic MPB as well as lactate, acetate and propionate oxidizing SRB were present in all reactor types investigated, except in an activated sludge reactor aerated with pure oxygen. Methane

  3. Aerobic uranium (VI) bioprecipitation by metal-resistant bacteria isolated from radionuclide-

    E-print Network

    Skolnick, Jeff

    Aerobic uranium (VI) bioprecipitation by metal-resistant bacteria isolated from radionuclide uranium [U(VI)] mediated by the intrinsic phosphatase acti- vities of naturally occurring bacteria such as uranium (U), technetium (Tc) and other toxic metals [e.g. cadmium (Cd), lead (Pb), chromium (Cr

  4. Determination of some characteristics coccoid forms of lactic acid bacteria isolated from Turkish kefirs with natural probiotic

    Microsoft Academic Search

    Z. N Yüksekda?; Y Beyatli; B Aslim

    2004-01-01

    In this study, a total of 21 coccoid forms of lactic acid bacteria (lactococci) were isolated from Turkish kefir samples. As a result of the identification tests, 21 lactococci isolates were identified as Lactococcus cremoris (11 strains), Lactococcus lactis (4 strains), Streptococcus thermophilus (3 strains) and Streptococcus durans (3 strains). The amount of produced lactic acid, hydrogen peroxide, proteolytic activity,

  5. Lactic acid starter and probiotic bacteria: a comparative “in vitro” study of probiotic characteristics and biological barrier resistance

    Microsoft Academic Search

    C. G. Vinderola; J. A. Reinheimer

    2003-01-01

    Probiotic characteristics (deconjugation of bile salts, hydrophobicity and ?-galactosidase activity) and the resistance to biological barriers (gastric juice and bile salts) of 24 strains of lactic acid starter bacteria (Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus and Lactococcus lactis) and 24 strains of probiotic bacteria (Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus rhamnosus and bifidobacteria) were compared. Among the probiotic bacteria tested, Lactobacillus

  6. Study of the possible mechanisms involved in the mucosal immune system activation by lactic acid bacteria.

    PubMed

    Perdigón, G; Vintiñi, E; Alvarez, S; Medina, M; Medici, M

    1999-06-01

    The induction of a mucosal immune response is not easy due to the development of oral tolerance, but under some conditions, bacteria can activate this immune system. Antigens administered orally can interact with M cells of Peyer's patches or bind to the epithelial cells. We have demonstrated that certain lactic acid bacteria are able to induce specific secretory immunity, and others will enhance the gut inflammatory immune response. The aim of this work was to establish the reason for these different behaviors and to define possible mechanisms involved in the interaction of lactic acid bacteria at the intestinal level. We studied IgA+ and IgM+ B cells comparatively in bronchus and intestine and CD4+ T cells and IgA anti-lactic acid bacteria antibodies in the intestinal fluid, induced by oral administration of Lactobacillus casei, Lb. delbrueckii ssp. bulgaricus, Lb. acidophilus, Lb. plantarum, Lb. rhamnosus, Lactococcus lactis, and Streptococcus salivarius ssp. thermophilus. The increase in the IgA+ B cells in the bronchus means that these lactic acid bacteria were able to induce the IgA cycle by interaction with M cells from Peyer's patches or intestinal epithelial cells. The IgM+ cells increased when the stimulus did not induce the switch from IgM+ to IgA+. The increase in the CD4+ cells suggests interaction of Peyer's patches and enhancement of the B- and T-cell migration. The anti-lactic acid bacteria antibody is related to the processing and presentation of the microorganisms to the immune cells. We demonstrated that Lb. casei and Lb. plantarum were able to interact with Peyer's patch cells and showed an increase in IgA-, CD4+ cells, and antibodies specific for the stimulating strain. Lactobacillus acidophilus induced gut mucosal activation by interaction with the epithelial cells without increase in the immune cells associated with the bronchus. Although Lb. rhamnosus and Strep. salivarius ssp. thermophilus interact with epithelial cells, they also induced an immune response against their epitopes. Lactococcus lactis and Lb. delbrueckii ssp. bulgaricus induced an increase of IgA+ cells entering the IgA cycle but not CD4+ cells; thus, these bacteria would have been bound to epithelial cells that activated B lymphocytes without processing and presenting of their epitopes. We did not determine specific antibodies against Lc. lactis or Lb. bulgaricus. PMID:10386296

  7. Diversity of Sulfur Compound Production in Lactic Acid Bacteria1

    Microsoft Academic Search

    K. E. Seefeldt; B. C. Weimer

    2000-01-01

    Volatile sulfur compounds such as methanethiol, di- methyl disulfide, dimethyl trisulfide, and hydrogen sul- fide constitute an important fraction of Cheddar cheese flavor. These compounds are products of the catabolism of methionine and cysteine by bacteria in the cheese matrix. The objectives of this study were to examine the levels and types of volatile sulfur compounds produced from methionine by

  8. Effects of morphological changes in beer-spoilage lactic acid bacteria on membrane filtration in breweries.

    PubMed

    Asano, Shizuka; Suzuki, Koji; Iijima, Kazumaru; Motoyama, Yasuo; Kuriyama, Hidetoshi; Kitagawa, Yasushi

    2007-10-01

    Membrane filter performance was investigated using beer-spoilage lactic acid bacteria (LAB). As a result, beer-adapted LAB strains showed considerably increased penetration rate through filters, as compared with non-adapted strains. Further statistical analyses demonstrated the significant shifts in cell size distribution towards shorter rods, when Lactobacillus brevis and L. lindneri strains were precultured in beer. These results indicate that diminished cell size is responsible for the deteriorated filter performance and, therefore, beer-adapted lactic acid bacteria are regarded as a serious threat to the production of unpasteurized beers. In addition, the selection of test strains and preculture conditions are suggested to be important for the rigorous and standardized evaluation of membrane filter performance in the brewing industry. PMID:18023809

  9. Amino acid profiles of lactic acid bacteria, isolated from kefir grains and kefir starter made from them

    Microsoft Academic Search

    Emilina Simova; Zhelyasko Simov; Dora Beshkova; Ginka Frengova; Zhechko Dimitrov; Zdravko Spasov

    2006-01-01

    The characteristics of cell growth, lactic acid production, amino acid release and consumption by single-strain cultures of lactic acid bacteria (isolated from kefir grains), and by a multiple-strain kefir starter prepared from them, were studied. The change in the levels of free amino acids was followed throughout the kefir process: single-strain kefir bacteria and the kefir starter (Lactococcus lactis C15–1%+Lactobacillus

  10. Effect of polymers and storage temperature on the stability of freeze-dried lactic acid bacteria

    Microsoft Academic Search

    Claude P. Champagne; Francine Mondou; Yves Raymond; Denis Roy

    1996-01-01

    The effect of the addition of gelatin, xanthan gum or maltodextrins on the survival during freeze-drying and stability during storage of four lactic acid bacteria were studied. The polymers were added to a milk-sucrose base medium and mixed with the cell concentrate. The water activity of the cultures was adjusted to 0.22 prior to storage at ?20, 4 or 20

  11. A rapid method for differentiation of dairy lactic acid bacteria by enzyme systems

    Microsoft Academic Search

    B. H. Lee; S. Haché; R. E. Simard

    1986-01-01

    Summary A rapid and simple technique utilizing the APIZYM enzymatic patterns complemented with arginine dihydrolase and citratase was developed for species differentiation of 40 lactic acid bacteria relevant to the dairy industry.Streptococcus species in general produced no ß-galactosidase, except forStreptococcus thermophilus. Lactobacillus species showed strong aminopeptidases and galactosidases but contained no arginine dihydrolase and citratase. Among the group N-streptococci,Streptococcus diacetylactis

  12. Lactic acid bacteria and yeasts in kefir grains and kefir made from them

    Microsoft Academic Search

    E Simova; D Beshkova; A Angelov; Ts Hristozova; G Frengova; Z Spasov

    2002-01-01

      In an investigation of the changes in the microflora along the pathway: kefir grains (A)?kefir made from kefir grains (B)?kefir\\u000a made from kefir as inoculum (C), the following species of lactic acid bacteria (83–90%) of the microbial count in the grains)\\u000a were identified: Lactococcus lactis subsp. lactis, Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus helveticus, Lactobacillus casei subsp. pseudoplantarum and

  13. Identification and characterization of the dominant lactic acid bacteria isolated from traditional fermented milk in Mongolia

    Microsoft Academic Search

    Z. H. Sun; W. J. Liu; J. C. Zhang; J. Yu; W. Gao; M. Jiri; B. Menghe; T. S. Sun; H. P. Zhang

    2010-01-01

    Five samples of Airag and 20 of Tarag (both in Mongolia) were collected from scattered households. One hundred strains of\\u000a lactic acid bacteria (LAB) were isolated and identified from these samples according to phenotypic characterization and 16S\\u000a rRNA gene sequence analysis. Eighty-five isolates belonged to the genus Lactobacillus, 15 being classified as coccoid LAB. All isolates belonged to 5 genera

  14. Structural and rheological characterisation of heteropolysaccharides produced by lactic acid bacteria in wheat and sorghum sourdough

    Microsoft Academic Search

    Sandra Galle; Clarissa Schwab; Elke K. Arendt; Michael G. Gänzle

    2011-01-01

    Hydrocolloids improve the volume, texture, and shelf life of bread. Exopolysaccharides (EPS) produced by lactic acid bacteria (LAB) during sourdough fermentation can replace hydrocolloids. It was the aim of this study to determine whether heteropolysaccharides (HePS) synthesized intracellularly from sugar nucleotides by glycosyltransferases are produced in wheat and gluten-free sorghum sourdough at effective levels. The HePS-producing strains Lactobacillus casei FUA3185,

  15. Diversity of amino acid converting enzymes in wild lactic acid bacteria

    Microsoft Academic Search

    P. Fernández de Palencia; M. de la Plaza; F. Amárita; T. Requena; C. Peláez

    2006-01-01

    A total of 156 lactic acid bacteria isolates belonging to the genera Lactococcus, Lactobacillus and Leuconostoc were analysed for the amino acid converting enzymes aminotransferases, glutamate dehydrogenase, and ?-ketoisovalerate decarboxylase. All isolates showed aminotransferase activity towards phenylalanine (substrate for the aromatic aminotransferase AraT) and isoleucine (substrate for the branched-chain aminotransferase BcaT). Although there was a high variability inter- and intra-species,

  16. Acute oral toxicity and bacterial translocation studies on potentially probiotic strains of lactic acid bacteria

    Microsoft Academic Search

    J. S Zhou; Q Shu; K. J Rutherfurd; J Prasad; P. K Gopal; H. S Gill

    2000-01-01

    Three potentially probiotic lactic acid bacteria (LAB) strains, Lactobacillus rhamnosus HN001 (DR20TM), Lb. acidophilus HN017 and Bifidobacterium lactis HN019 (DR10™), have recently been identified and characterized. The present study was designed to evaluate the acute oral toxicity of these strains to mice, and also to investigate bacterial translocation and gut mucosal pathology in BALB\\/c mice fed HN019, HN001 or HN017

  17. Interactions Among Lactic Acid Starter and Probiotic Bacteria Used for Fermented Dairy Products

    Microsoft Academic Search

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

    2002-01-01

    Interactions among lactic acid starter and probiotic bacteria were investigatedto establish adequate combi- nations of strains to manufacture probiotic dairy prod- ucts. For this aim, a total of 48 strains of Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgari- cus, Lactococcus lactis, Lactobacillus acidophilus, Lac- tobacilluscasei,andBifidobacteriumspp.(eightofeach) were used. The detection of bacterial interactions was carried out using the well-diffusion agar assay, and

  18. Colonization and probiotic effects of lactic acid bacteria in the gut of the abalone Haliotis gigantea

    Microsoft Academic Search

    Shunpei Iehata; Tadashi Inagaki; Suguru Okunishi; Miyo Nakano; Reiji Tanaka; Hiroto Maeda

    2009-01-01

    Strains of lactic acid bacteria (LAB) were isolated from several different sources and evaluated in vitro for potential probiotic\\u000a effects in abalones. Two isolates (Lactobacillus sp. strain a3 and Enterococcus sp. strain s6) were highly resistant to bile salt and\\/or gastric juice and inhibited the growth of three abalone pathogens\\u000a (Listonella anguillarum, Vibrio harveyi, and V. carchariae). Each of the

  19. Fermented Milk–Starch and Milk–Inulin Products as Vehicles for Lactic Acid Bacteria

    Microsoft Academic Search

    ANGELA ZULETA; MARÍA I. SARCHI; MARÍA E. RIO; MARÍA E. SAMBUCETTI; MARCELO MORA; SUSANA V. DE FABRIZIO; JOSÉ L. PARADA

    2004-01-01

    Formulations using cassava starch or inulin plus milk were fermented with three different lactic acid bacteria (LAB) strains: Lactobacillus plantarum D34, Lactobacillus sp. SLH6, and Streptococcus thermophilus ST4. Growth and acidification were followed in 3% powdered milk (M3), 3% milk–6% starch (M3-S6), and 3% milk–6% inulin (M3-In6). D34 and SLH6 growth was enhanced by starch in M3-S6, when compared to

  20. Growth of lactic acid bacteria on oilseed crop pea- and chickpea-based media

    Microsoft Academic Search

    Baida Djeghri-Hocine; Messaouda Boukhemis; Nourredine Zidoune; Abdeltif Amrane

    2007-01-01

    Six strains of lactic acid bacteria isolated from different biotopes were cultivated on oilseed crop pea- or chickpea-based\\u000a media, supplemented with the usual nitrogen supplements, yeast extract, meat extract or tryptic casein peptone. Growth was\\u000a compared to that recorded on the widely used MRS and M17 media. All the media tested favoured growth of the selected strains,\\u000a since the final

  1. Production of class II bacteriocins by lactic acid bacteria; an example of biological warfare and communication

    Microsoft Academic Search

    Vincent G. H. Eijsink; Lars Axelsson; Dzung B. Diep; Leiv S. Håvarstein; Helge Holo; Ingolf F. Nes

    2002-01-01

    Lactic acid bacteria (LAB) fight competing Gram-positive microorganisms by secreting anti-microbial peptides called bacteriocins.\\u000a Peptide bacteriocins are usually divided into lantibiotics (class I) and non-lantibiotics (class II), the latter being the\\u000a main topic of this review. During the past decade many of these bacteriocins have been isolated and characterized, and elements\\u000a of the genetic mechanisms behind bacteriocin production have been

  2. Phenotypic and technological diversity of lactic acid bacteria and staphylococci isolated from traditionally fermented sausages in southern Greece.

    PubMed

    Drosinos, Eleftherios H; Paramithiotis, Spiros; Kolovos, George; Tsikouras, Ioannis; Metaxopoulos, Ioannis

    2007-05-01

    The physicochemical and microbiological characteristics of spontaneously fermented sausages made by two medium-sized enterprises (MSE) located in southern Greece have been studied. A total of 300 lactic acid bacteria and 300 staphylococcal strains have been isolated and identified by their physiological characteristics. Lactobacillus plantarum strains were found to dominate the lactic acid bacteria microbiota in most of the cases with L. sakei strains prevailing in some of them and L. rhamnosus strains occasionally accompanying the dominant lactic acid bacteria microbiota. On the other hand, S. saprophyticus strains were found to dominate the staphylococcal microbiota in all spontaneously fermented sausages with of S. simulans, S. xylosus, S. gallinarum and S. cohnii cohnii strains being sporadically present. Following the identification, an evaluation of their technological properties, namely proteolytic and lipolytic capacities as well as production of biogenic amines and antimicrobial compounds, took place. None of the lactic acid bacteria and staphylococci was found to possess lipolytic activity whereas a total of 6 lactic acid bacteria and 51 staphylococci strains were found to be able to hydrolyse either the sarcoplasic, myofibrillar or both protein fractions. Furthermore, only one L. sakei strain and 185 staphylococci strains were found to possess decarboxylase activity against lysine, tyrosine, ornithine or histidine. Finally none of the staphylococcal microbiota and 3 lactic acid bacteria strains were found to be able to produce antimicrobial compounds of proteinaceous nature against Listeria monocytogenes. PMID:17188204

  3. Occurrence of an Inhibitor of Lactic Acid Bacteria in Green Olives1

    PubMed Central

    Fleming, H. P.; Etchells, J. L.

    1967-01-01

    Green olives were found to contain an inhibitor(s) of several species of lactic acid bacteria usually associated with the Spanish-type brined olive fermentation. The inhibitor was demonstrated by the presence of inhibition zones surrounding tissue which had been cut from frozen olives and implanted in a seeded nutritive agar medium. Relative potencies of aqueous extracts of frozen olives were determined by a paper disc assay method. The Mission variety of olive contained the most inhibitor, and the Manzanillo and Ascolano, about 50 and 40% as much as the Mission variety, respectively. Sevillano and Barouni varieties contained comparatively little inhibitor. Effects of the inhibitor on growth rates of lactic acid bacteria were determined by adding various amounts of a concentrated aqueous extract of olives to a nutritive broth medium contained in screw-capped tubes. Of the four species of lactic acid bacteria tested, Leuconostoc mesenteroides was the most sensitive, and Lactobacillus plantarum was the least sensitive; Pediococcus cerevisiae and Lactobacillus brevis were intermediate in sensitivity. Extracts possessed a bactericidal property, as evidenced by their effect on L. mesenteroides. Sodium chloride, especially at concentrations of about 5% and higher, greatly increased the effectiveness of the inhibitor. The inhibitor was ethyl alcohol-soluble and was stable when heated at 100 C in aqueous solution. Potencies of extracts were reduced greatly by adjustment to pH 10, but no appreciable effect was noted by adjustment to pH 0.8. Images Fig. 1 PMID:16349729

  4. Behavior of Psychrotrophic Lactic Acid Bacteria Isolated from Spoiling Cooked Meat Products

    PubMed Central

    Hamasaki, Yoshikatsu; Ayaki, Mitsuko; Fuchu, Hidetaka; Sugiyama, Masaaki; Morita, Hidetoshi

    2003-01-01

    Three kinds of lactic acid bacteria were isolated from spoiling cooked meat products stored below 10°C. They were identified as Leuconostoc mesenteroides subsp. mesenteroides, Lactococcus lactis subsp. lactis, and Leuconostoc citreum. All three strains grew well in MRS broth at 10°C. In particular, L. mesenteroides subsp. mesenteroides and L. citreum grew even at 4°C, and their doubling times were 23.6 and 51.5 h, respectively. On the other hand, although the bacteria were initially below the detection limit (<10 CFU/g) in model cooked meat products, the bacterial counts increased to 108 CFU/g at 10°C after 7 to 12 days. PMID:12788779

  5. Understanding the industrial application potential of lactic acid bacteria through genomics.

    PubMed

    Zhu, Yan; Zhang, Yanping; Li, Yin

    2009-06-01

    Lactic acid bacteria (LAB) are a heterogeneous group of bacteria contributing to various industrial applications, ranging from food and beverage fermentation, bulk and fine chemicals production to pharmaceuticals manufacturing. Genome sequencing is booming; hitherto, 25 genomes of LAB have been published and many more are in progress. Based on genomic content of LAB, this review highlights some findings related to applications revealed by genomics and functional genomics analyses. Finally, this review summarizes mathematical modeling strategies of LAB in the context of genomics, to further our understanding of industrial related features. PMID:19466404

  6. Development of radiation sterilized dip slides for enumerating lactic acid bacteria and total count in foodstuffs

    NASA Astrophysics Data System (ADS)

    Eisenberg, E.; Padova, R.; Kirsch, E.; Weissman, Sh.; Hirshfeld, T.; Shenfeld, A.

    APT agar (APT) used for enumeration of lactic acid bacteria and Plate Count agar (PCA) applied for total count were sterilized by gamma radiation using radiation dose of 10-15 kGy. Radiosterilized PCA and APT modified by adding catalase prior to irradiation, or APT with increased content of yeast extract performed, as well as, the heat sterilized commercial media. Growth performance was evaluated on several strains of microorganisms, as well as, by enumeration of bacteria in food products. Radiosterilization of culture media in final packaging, can be applied to produce dip slide kits containing PCA or APT.

  7. Heterologous surface display on lactic acid bacteria: non-GMO alternative?

    PubMed

    Zadravec, Petra; Štrukelj, Borut; Berlec, Aleš

    2015-05-01

    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. PMID:25880164

  8. Genetically modified lactic acid bacteria: applications to food or health and risk assessment.

    PubMed

    Renault, Pierre

    2002-11-01

    Lactic acid bacteria have a long history of use in fermented food products. Progress in gene technology allows their modification by introducing new genes or by modifying their metabolic functions. These modifications may lead to improvements in food technology (bacteria better fitted to technological processes, leading to improved organoleptic properties em leader ), or to new applications including bacteria producing therapeutic molecules that could be delivered by mouth. Examples in these two fields will be discussed, at the same time evaluating their potential benefit to society and the possible risks associated with their use. Risk assessment and expected benefits will determine the future use of modified bacteria in the domains of food technology and health. PMID:12595135

  9. Aerobic Anoxygenic Photosynthesis in Roseobacter Clade Bacteria from Diverse Marine Habitats

    Microsoft Academic Search

    Martin Allgaier; Heike Uphoff; Andreas Felske; Irene Wagner-Dobler

    2003-01-01

    The marine Roseobacter clade comprises several genera of marine bacteria related to the uncultured SAR83 cluster, the second most abundant marine picoplankton lineage. Cultivated representatives of this clade are physiologically heterogeneous, and only some have the capability for aerobic anoxygenic photosynthesis, a process of potentially great ecological importance in the world's oceans. In an attempt to correlate phylogeny with ecology,

  10. Concentrations of butyric acid bacteria spores in silage and relationships with aerobic deterioration

    Microsoft Academic Search

    M. M. M. Vissers; F. Driehuis; M. C. Te Giffel; P. De Jong; J. M. G. Lankveld

    2007-01-01

    Germination and growth of spores of butyric acid bacteria (BAB) may cause severe defects in semihard cheeses. Silage is the main source of BAB spores in cheese milk. The objectives of the study were to deter- mine the significance of grass silages and corn silages assourcesofBABsporesandtoinvestigatetherelation- ships between high concentrations of BAB spores in corn silage and aerobic deterioration. In

  11. Biofilm formation and contamination of cheese by nonstarter lactic acid bacteria in the dairy environment.

    PubMed

    Somers, E B; Johnson, M E; Wong, A C

    2001-09-01

    Defects in cheese, such as undesirable flavors, gas formation, or white surface haze from calcium lactate crystals, can result from growth of nonstarter lactic acid bacteria (NSLAB). The potential for biofilm formation by NSLAB during cheese manufacturing, the effect of cleaning and sanitizing on the biofilm, and bacterial growth and formation of defects during ripening of the contaminated cheese were studied. Stirred-curd Cheddar cheese was made in the presence of stainless steel chips containing biofilms of either of two strains of erythromycin-resistant NSLAB (Lactobacillus curvatus strain JBL2126 or Lactobacillus fermentum strain AWL4001). During ripening, the cheese was assayed for total lactic acid bacteria, numbers of NSLAB, and percentage of lactic acid isomers. Biofilms of L. curvatus formed during cheese making survived the cleaning process and persisted in a subsequent batch of cheese. The starter culture also survived the cleaning process. Additionally, L. curvatus biofilms present in the vat dislodged, grew to high numbers, and caused a calcium lactate white haze defect in cheese during ripening. On the other hand, biofilms of L. fermentum sloughed off during cheese making but could not compete with other NSLAB present in cheese during ripening. Pulsed-field gel electrophoresis results verified the presence of the two biofilm strains during cheese making and in the ripening cheese. Probable contamination sites in the plant for other NSLAB isolated in the cheese were identified, thus supporting the hypothesis that resident NSLAB biofilms are a viable source of contamination in the dairy environment. PMID:11573770

  12. Phenotypic and Genotypic Characterization of Some Lactic Acid Bacteria Isolated from Bee Pollen: A Preliminary Study

    PubMed Central

    BELHADJ, Hani; HARZALLAH, Daoud; BOUAMRA, Dalila; KHENNOUF, Seddik; Dahamna, Saliha; GHADBANE, Mouloud

    2014-01-01

    In the present work, five hundred and sixty-seven isolates of lactic acid bacteria were recovered from raw bee pollen grains. All isolates were screened for their antagonistic activity against both Gram-positive and Gram-negative pathogenic bacteria. Neutralized supernatants of 54 lactic acid bacteria (LAB) cultures from 216 active isolates inhibited the growth of indicator bacteria. They were phenotypically characterized, based on the fermentation of 39 carbohydrates. Using the simple matching coefficient and unweighted pair group algorithm with arithmetic averages (UPGMA), seven clusters with other two members were defined at the 79% similarity level. The following species were characterized: Lactobacillus plantarum, Lactobacillus fermentum, Lactococcus lactis, Pediococcus acidilactici, Pediococcus pentosaceus, and unidentified lactobacilli. Phenotypic characteristics of major and minor clusters were also identified. Partial sequencing of the 16S rRNA gene of representative isolates from each cluster was performed, and ten strains were assigned to seven species: Lactobacillus plantarum, Lactobacillus fermentum, Lactococcus lactis, Lactobacillus ingluviei, Pediococcus pentosaceus, Lactobacillus acidipiscis and Weissella cibaria. The molecular method used failed to determine the exact taxonomic status of BH0900 and AH3133. PMID:24936378

  13. The aflatoxin B1 isolating potential of two lactic acid bacteria

    PubMed Central

    Hamidi, Adel; Mirnejad, Reza; Yahaghi, Emad; Behnod, Vahid; Mirhosseini, Ali; Amani, Sajad; Sattari, Sara; Darian, Ebrahim Khodaverdi

    2013-01-01

    Objective To determine lactic acid bacteria's capability to enhance the process of binding and isolating aflatoxin B1 and to utilize such lactic acid bacteria as a food supplement or probiotic products for preventing absorption of aflatoxin B1 in human and animal bodies. Methods In the present research, the bacteria were isolated from five different sources. For surveying the capability of the bacteria in isolating aflatoxin B1, ELISA method was implemented, and for identifying the resultant strains through 16S rRNA sequencing method, universal primers were applied. Results Among the strains which were isolated, two strains of Lactobacillus pentosus and Lactobacillus beveris exhibited the capability of absorbing and isolating aflatoxin B1 by respectively absorbing and discharging 17.4% and 34.7% of the aforementioned toxin existing in the experiment solution. Conclusions Strains of Lactobacillus pentosus and Lactobacillus beveris were isolated from human feces and local milk samples, respectively. And both strains has the ability to isolate or bind with aflatoxin B1. PMID:23998015

  14. Local domestication of lactic acid bacteria via cassava beer fermentation

    PubMed Central

    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. PMID:25071997

  15. Fate of Chlortetracycline and Tylosin-Resistant Bacteria in an Aerobic Thermophilic Sequencing Batch Reactor Treating Swine Waste

    Microsoft Academic Search

    Martin R. Chénier; Pierre Juteau

    2009-01-01

    Antibiotics have been added to animal feed for decades. Consequently, food animals and their wastes constitute a reservoir\\u000a of antibiotic-resistant bacteria. The objective of this work was to characterize the impact of an aerobic thermophilic biotreatment\\u000a on aerobic, antibiotic-resistant bacteria in swine waste. The proportion of tylosin- and chlortetracycline-resistant bacteria\\u000a grown at 25°C, 37°C, and 60°C decreased after treatment, but

  16. Aflatoxin B1 binding capacity of autochthonous strains of lactic acid bacteria.

    PubMed

    Fazeli, Mohammad R; Hajimohammadali, M; Moshkani, Azamossadat; Samadi, Nasrin; Jamalifar, Hossein; Khoshayand, Mohammad R; Vaghari, Elham; Pouragahi, Samieh

    2009-01-01

    Some foods are prone to contamination with aflatoxins, with detrimental effect on human health. Lactic acid bacteria have been reported to bind aflatoxins and remove them from foods and feeds. Reduction of aflatoxin B1 (AFB1) from the liquid media by the autochthonous lactic acid bacteria (Lactobacillus casei, Lactobacillus plantarum, and Lactobacillus fermentum) isolated from traditional Iranian sourdough and dairy products is reported in the current study. The effect of incubation time on the binding capacity of the strains to AFB1 was also investigated. Duplicates of individual bacteria with population equivalent to 2 X 10(10) CFU/ml were incubated in the presence of AFB1 at 37 degrees C for a period of 72 h, and the amounts of unbound AFB1 were quantitated by reverse-phase high-performance liquid chromatography. All the strains were capable of removal of AFB1, and the reduction of AFB1 ranged from 25 to 61% throughout the incubation period. Removal of AFB1 was a rapid process, with approximately 61 and 56% of the toxin taken instantly by L. fermentum and L. plantarum, respectively. Binding was of a reversible nature, and some of the bound AFB1 was released into the media by the repeated centrifugation and resuspension of the cell pellets. The stability of the bacteria-toxin complex was strain dependent, and L. casei was a stronger binder of AFB1 compared with the other bacteria. No toxin release was observed after 24 h. These findings tend to suggest that certain novel probiotic bacteria with high aflatoxin binding capacity could be selected for detoxification of foods. PMID:19205485

  17. Identification and characterization of lactic Acid bacteria in a commercial probiotic culture.

    PubMed

    Menconi, Anita; Kallapura, Gopala; Latorre, Juan D; Morgan, Marion J; Pumford, Neil R; Hargis, Billy M; Tellez, Guillermo

    2014-01-01

    The aim of the present study was to describe the identification and characterization (physiological properties) of two strains of lactic acid bacteria (LAB 18 and 48) present in a commercial probiotic culture, FloraMax(®)-B11. Isolates were characterized morphologically, and identified biochemically. In addition, the MIDI System ID, the Biolog ID System, and 16S rRNA sequence analyses for identification of LAB 18 and LAB 48 strains were used to compare the identification results. Tolerance and resistance to acidic pH, high osmotic concentration of NaCl, and bile salts were tested in broth medium. In vitro assessment of antimicrobial activity against enteropathogenic bacteria and susceptibility to antibiotics were also tested. The results obtained in this study showed tolerance of LAB 18 and LAB 48 to pH 3.0, 6.5% NaCl and a high bile salt concentration (0.6%). Both strains evaluated showed in vitro antibacterial activity against Salmonella enterica serovar Enteritidis, Escherichia coli (O157:H7), and Campylobacter jejuni. These are important characteristics of lactic acid bacteria that should be evaluated when selecting strains to be used as probiotics. Antimicrobial activity of these effective isolates may contribute to efficacy, possibly by direct antimicrobial activity in vivo. PMID:24936379

  18. Survival of Listeria monocytogenes, Listeria innocua, and lactic acid bacteria in chill brines.

    PubMed

    Boyer, R R; Matak, K; Sumner, S S; Meadows, B; Williams, R C; Eifert, J D; Birbari, W

    2009-06-01

    Listeria monocytogenes is the pathogen of concern in ready-to-eat (RTE) meat products. Salt brines are used to chill processed meats. L. monocytogenes and lactic acid bacteria (LAB) can grow under saline conditions, and may compete with each other for nutrients. The objective of this study was to determine the effect of lactic acid bacteria (Enterococcus faecalis, Carnobacterium gallinarum, and Lactobacillus plantarum) on the survival of L. monocytogenes and Listeria innocua in brines stored under low temperatures for 10 d. Sterile tap water (STW) and 2 brine solutions (7.9% and 13.2% NaCl) were inoculated with 1 of 5 cocktails (L. monocytogenes, L. innocua, LAB, L. monocytogenes+ LAB, or L. innocua+ LAB) at initial concentrations of 7 log CFU/mL. Brines were stored for 10 d at 4 or 12 degrees C. Three replications of each brine concentration/cocktail/temperature combination were completed. No significant reductions of L. monocytogenes occurred in 7.9%[w/v] or 13.2%[w/v] brines when LAB were present; however, there were significant reductions after 10 d of L. monocytogenes in the STW solution when LAB were present (1.43 log CFU/mL at 4 degrees C and 3.02 log CFU/mL at 12 degrees C). L. innocua was significantly less resilient to environmental stresses of the brines than L. monocytogenes, both with and without LAB present (P< or = 0.05). These strains of lactic acid bacteria are not effective at reducing L. monocytogenes in brines at low temperatures. Furthermore, use of L. innocua as a model for L. monocytogenes is not appropriate under these environmental conditions. PMID:19646051

  19. Lactic Acid Bacteria in an Oat-based Non-dairy Milk Substitute: Fermentation Characteristics and Exopolysaccharide Formation

    Microsoft Academic Search

    Olof Mårtensson; Rickard Öste; Olle Holst

    2000-01-01

    Nine strains of lactic acid bacteria were tested for fermentation characteristics in an oat- based, non-dairy milk substitute, Mill MilkTM (MM medium). Viable counts, aroma formation, lactic acid production and viscosity were the parameters investigated. In general, bacterial strains grown at 30°C yielded a better flavour and higher viable counts than those incubated at 37°C. Strains were selected for their

  20. Practical implications of lactate and pyruvate metabolism by lactic acid bacteria in food and beverage fermentations.

    PubMed

    Liu, S-Q

    2003-06-15

    This article reviews the metabolism of pyruvate and lactate by lactic acid bacteria (LAB) involved in food and beverage fermentations with an emphasis on practical implications. First, the formation of pyruvate and lactate from a range of substrates, including carbohydrates, organic acids and amino acids, is briefly described. The catabolism of pyruvate and lactate by LAB is then reviewed. This is followed by a discussion of lactate degradation and racemisation by LAB from specific fermented foods and beverages. Finally, the impact of environmental factors and metabolic engineering on pyruvate and lactate metabolism by LAB is evaluated with regard to practical significance. PMID:12706034

  1. Conservation of the Major Cold Shock Protein in Lactic Acid Bacteria

    Microsoft Academic Search

    Woojin S. Kim; Nongpanga Khunajakr; Jun Ren; Noel W. Dunn

    1998-01-01

    .   Primers designed from consensus regions of the major cold shock gene of different bacterial species were used in PCR amplification\\u000a of Lactic Acid Bacteria (LAB). An appropriately-sized PCR product was obtained from Lactococcus lactis subsp. lactis LL43-1 and MG1363; Lactococcus lactis subsp. cremoris LC10-1, LC11-1, and LC12-1; Streptococcus thermophilus ST1-1; Enterococcus faecalis EF1-1; Lactobacillus acidophilus LA1-1; Lactobacillus helveticus LH1-1;

  2. Non-starter lactic acid bacteria used to improve cheese quality and provide health benefits.

    PubMed

    Settanni, Luca; Moschetti, Giancarlo

    2010-09-01

    Non-starter lactic acid bacteria (NSLAB) dominate cheese microbiota during ripening. They tolerate the hostile environment well and strongly influence the biochemistry of curd maturation, contributing to the development of the final characteristics of cheese. Several NSLAB are selected on the basis of their health benefits (enhancement of intestinal probiosis, production of bioactive peptides, generation of gamma-aminobutyric acid and inactivation of antigenotoxins) and are employed in cheese-making. This review describes the ecology of NSLAB, and focuses on their application as adjunct cultures, in order to drive the ripening process and promote health advantages. The scopes of future directions of research are summarised. PMID:20630311

  3. Lactic acid bacteria and their controversial role in fresh meat spoilage.

    PubMed

    Pothakos, Vasileios; Devlieghere, Frank; Villani, Francesco; Björkroth, Johanna; Ercolini, Danilo

    2015-11-01

    Lactic acid bacteria (LAB) constitute a heterogeneous group that has been widely associated with fresh meat and cooked meat products. They represent a controversial cohort of microbial species that either contribute to spoilage through generation of offensive metabolites and the subsequent organoleptic downgrading of meat or serve as bioprotective agents with strains of certain species causing unperceivable or no alterations. Therefore, significant distinction among biotypes is substantiated by studies determining spoilage potential as a strain-specific trait corroborating the need to revisit the concept of spoilage. PMID:25972087

  4. Metabolic engineering of lactic acid bacteria for the production of industrially important compounds

    PubMed Central

    Papagianni, Maria

    2012-01-01

    Lactic acid bacteria (LAB) are receiving increased attention for use as cell factories for the production of metabolites with wide use by the food and pharmaceutical industries. The availability of efficient tools for genetic modification of LAB during the past decade permitted the application of metabolic engineering strategies at the levels of both the primary and the more complex secondary metabolism. The recent developments in the area with a focus on the production of industrially important metabolites will be discussed in this review. PMID:24688663

  5. Moisture Requirements for Growth and Metabolite Production by Lactic Acid Bacteria

    PubMed Central

    Troller, J. A.; Stinson, J. V.

    1981-01-01

    The effect of water activity (aw) reduction on growth and acid and diacetyl production by three lactic streptococci was studied. In addition, the influence of low moisture conditions on several bacteria of significance in the fermentation of sauerkraut was examined. The minimal aw supporting growth of dairy lactics was 0.93 in a medium adjusted with glycerol. Media adjusted with sucrose generally were more inhibitory than those in which glycerol was the humectant. Titratable acidity, although not related to the type of humectant, did depend on the aw of the medium and was directly related to the extent of growth. Diacetyl concentration increased in cultures of reduced aw when the media were adjusted with both humectants; however, the effect was greatest with glycerol. A lactic strain associated with sauerkraut fermentation appeared to grow at a lower minimal aw in a glycerol-adjusted medium than in a system adjusted with NaCl; however, none of the sauerkraut organisms grew at aw levels of <0.95 when NaCl was the solute. Acid production appeared to be related to the presence and extent of growth at all of the aw levels studied. PMID:16345867

  6. Moisture requirements for growth and metabolite production by lactic Acid bacteria.

    PubMed

    Troller, J A; Stinson, J V

    1981-10-01

    The effect of water activity (a(w)) reduction on growth and acid and diacetyl production by three lactic streptococci was studied. In addition, the influence of low moisture conditions on several bacteria of significance in the fermentation of sauerkraut was examined. The minimal a(w) supporting growth of dairy lactics was 0.93 in a medium adjusted with glycerol. Media adjusted with sucrose generally were more inhibitory than those in which glycerol was the humectant. Titratable acidity, although not related to the type of humectant, did depend on the a(w) of the medium and was directly related to the extent of growth. Diacetyl concentration increased in cultures of reduced a(w) when the media were adjusted with both humectants; however, the effect was greatest with glycerol. A lactic strain associated with sauerkraut fermentation appeared to grow at a lower minimal a(w) in a glycerol-adjusted medium than in a system adjusted with NaCl; however, none of the sauerkraut organisms grew at a(w) levels of <0.95 when NaCl was the solute. Acid production appeared to be related to the presence and extent of growth at all of the a(w) levels studied. PMID:16345867

  7. Characterization of Lactic Acid Bacteria Isolated from Sauce-type Kimchi

    PubMed Central

    Jung, Suk Hee; Park, Joung Whan; Cho, Il Jae; Lee, Nam Keun; Yeo, In-Cheol; Kim, Byung Yong; Kim, Hye Kyung; Hahm, Young Tae

    2012-01-01

    This study was carried out to investigate the isolation and characterization of lactic acid bacteria (LAB) from naturally fermented sauce-type kimchi. Sauce-type kimchi was prepared with fresh, chopped ingredients (Korean cabbage, radish, garlic, ginger, green onion, and red pepper). The two isolated bacteria from sauce-type kimchi were identified as Pediococcus pentosaceus and Lactobacillus brevis by 16S rDNA sequencing and tentatively named Pediococcus sp. IJ-K1 and Lactobacillus sp. IJ-K2, respectively. Pediococcus sp. IJ-K1 was isolated from the early and middle fermentation stages of sauce-type kimchi whereas Lactobacillus sp. IJ-K2 was isolated from the late fermentation stage. The resistance of Pediococcus sp. IJ-K1 and Lactobacillus sp. IJ-K2 to artificial gastric and bile acids led to bacterial survival rates that were 100% and 84.21%, respectively. PMID:24471087

  8. Novel bacteriocins from lactic acid bacteria (LAB): various structures and applications.

    PubMed

    Perez, Rodney H; Zendo, Takeshi; Sonomoto, Kenji

    2014-08-29

    Bacteriocins are heat-stable ribosomally synthesized antimicrobial peptides produced by various bacteria, including food-grade lactic acid bacteria (LAB). These antimicrobial peptides have huge potential as both food preservatives, and as next-generation antibiotics targeting the multiple-drug resistant pathogens. The increasing number of reports of new bacteriocins with unique properties indicates that there is still a lot to learn about this family of peptide antibiotics. In this review, we highlight our system of fast tracking the discovery of novel bacteriocins, belonging to different classes, and isolated from various sources. This system employs molecular mass analysis of supernatant from the candidate strain, coupled with a statistical analysis of their antimicrobial spectra that can even discriminate novel variants of known bacteriocins. This review also discusses current updates regarding the structural characterization, mode of antimicrobial action, and biosynthetic mechanisms of various novel bacteriocins. Future perspectives and potential applications of these novel bacteriocins are also discussed. PMID:25186038

  9. Aerobic Anoxygenic Phototrophic Bacteria in the Mid-Atlantic Bight and the North Pacific Gyre. Revised

    NASA Technical Reports Server (NTRS)

    Cottrell, Matthew T.; Mannino, Antonio; Kirchman, David L.

    2005-01-01

    The abundance of aerobic anoxygenic phototrophic (AM) bacteria, cyanobacteria and heterotrophs was examined in the Mid-Atlantic Bight and the central North Pacific gyre using infrared fluorescence microscopy coupled with image analysis and flow cytometry. AAP bacteria comprised 5% to 16% of total prokaryotes in the Atlantic but only 5% or less in the Pacific. In the Atlantic, AAP bacterial abundance was as much as 2-fold higher than Prochlorococcus and 10-folder higher than Synechococcus. In contrast, Prochlorococcus outnumbered AAP bacteria 5- to 50-fold in the Pacific. In both oceans, subsurface abundance maxima occurred within the photic zone, and AAP bacteria were least abundant below the 1% light depth. Concentrations of bacteriochlorophyll a (BChl a) were low (approx.1%) compared to chlorophyll a. Although the BChl a content of AAP bacteria per cell was typically 20- to 250-fold lower than the divinyl-chlorophyll a content of Prochlorococcus, in shelf break water the pigment content of AAP bacteria approached that of Prochlorococcus. The abundance of AAP bacteria rivaled some groups of strictly heterotrophic bacteria and was often higher than the abundance of known AAP genera (Erythrobacter and Roseobacter spp.). The distribution of AAP bacteria in the water column, which was similar in the Atlantic and the Pacific, was consistent with phototrophy.

  10. The lactic acid bacteria metabolite phenyllactic acid inhibits both radial growth and sporulation of filamentous fungi

    PubMed Central

    2013-01-01

    Background Food spoilage caused by molds is a severe problem. In food and feed, e.g. dairy products, sourdough bread and silage, lactic acid bacteria are used as starter cultures. Besides lactic and acetic acid, some strains produce other low molecular weight compounds with antifungal activities. One of these metabolites is phenyllactic acid (PLA), well known for its antifungal effect. The inhibitory effect of PLA has only partially been investigated, and the objective of this study was to elucidate in detail the antifungal properties of PLA. Results We investigated the outgrowth of individual conidia from Aspergillus niger, Cladosporium cladosporioides and Penicillium roqueforti, and observed the morphologies of resulting colonies on solid media using different acid concentrations. We found that PLA inhibits molds similar to weak acid preservatives. Furthermore, it has an additional activity: at sub-inhibitory concentrations, fungal colonies displayed slower radial growth and inhibited sporulation. The L isoform of PLA is a more potent inhibitor than the D form. Increased expression of phiA was observed during PLA treatment. This gene was initially identified as being induced by Streptomyces-produced macrolide antibiotics, and is shown to be a structural protein in developed cells. This suggests that PhiA may act as a general stress protectant in fungi. Conclusion From a food protection perspective, the results of this study support the usage of lactic acid bacteria strains synthesizing PLA as starter cultures in food and feed. Such starter cultures could inhibit spore synthesis, which would be beneficial as many food borne fungi are spread by airborne spores. PMID:24229396

  11. Honeybees and beehives are rich sources for fructophilic lactic acid bacteria.

    PubMed

    Endo, Akihito; Salminen, Seppo

    2013-09-01

    Fructophilic lactic acid bacteria (FLAB) are a specific group of lactic acid bacteria (LAB) characterized and described only recently. They prefer fructose as growth substrate and inhabit only fructose-rich niches. Honeybees are high-fructose-consuming insects and important pollinators in nature, but reported to be decreasing in the wild. In the present study, we analyzed FLAB microbiota in honeybees, larvae, fresh honey and bee pollen. A total of 66 strains of LAB were isolated from samples using a selective isolation technique for FLAB. Surprisingly, all strains showed fructophilic characteristics. The 66 strains and ten FLAB strains isolated from flowers in a separate study were genotypically separated into six groups, four of which being identified as Lactobacillus kunkeei and two as Fructobacillus fructosus. One of the L. kunkeei isolates showed antibacterial activity against Melissococcus plutonius, a causative pathogen of European foulbrood, this protection being attributable to production of an antibacterial peptide or protein. Culture-independent analysis suggested that bee products and larvae contained simple Lactobacillus-group microbiota, dominated by L. kunkeei, although adult bees carried a more complex microbiota. The findings clearly demonstrate that honeybees and their products are rich sources of FLAB, and FLAB are potential candidates for future bee probiotics. PMID:23845309

  12. Sourdough lactic acid bacteria: exploration of non-wheat cereal-based fermentation.

    PubMed

    Coda, Rossana; Cagno, Raffaella Di; Gobbetti, Marco; Rizzello, Carlo Giuseppe

    2014-02-01

    Cereal-based foods represent a very important source of biological as well as of cultural diversity, as testified by the wide range of derived fermented products. A trend that is increasingly attracting bakery industries as well as consumers is the use of non-conventional flours for the production of novel products, characterised by peculiar flavour and better nutritional value. Lactic acid bacteria microbiota of several non-wheat cereals and pseudo-cereals has been recently deeply investigated with the aim of studying the biodiversity and finding starter cultures for sourdough fermentation. Currently, the use of ancient or ethnic grains is mainly limited to traditional typical foods and the bread making process is not well standardised with consequent negative effects on the final properties. The challenge in fermenting such grains is represented by the necessity to combine good technology and sensory properties with nutritional/health benefits. The choice of the starter cultures has a critical impact on the final quality of cereal-based products, and strains that dominate and outcompete contaminants should be applied for specific sourdough fermentations. In this sense, screening and characterisation of the lactic acid bacteria microbiota is very useful in the improvement of a peculiar flour, from both a nutritional and technological point of view. PMID:24230473

  13. Technological and functional applications of low-calorie sweeteners from lactic acid bacteria.

    PubMed

    Patra, F; Tomar, S K; Arora, S

    2009-01-01

    Lactic acid bacteria (LAB) have been extensively used for centuries as starter cultures to carry out food fermentations and are looked upon as burgeoning "cell factories" for production of host of functional biomolecules and food ingredients. Low-calorie sugars have been a recent addition and have attracted a great deal of interest of researchers, manufacturers, and consumers for varied reasons. These sweeteners also getting popularized as low-carb sugars have been granted generally recommended as safe (GRAS) status by the U.S. Federal Drug Administration (USFDA) and include both sugars and sugar alcohols (polyols) which in addition to their technological attributes (sugar replacer, bulking agent, texturiser, humectant, cryoprotectant) have been observed to exert a number of health benefits (low calories, low glycemic index, anticariogenic, osmotic diuretics, obesity control, prebiotic). Some of these sweeteners successfully produced by lactic acid bacteria include mannitol, sorbitol, tagatose, and trehalose and there is a potential to further enhance their production with the help of metabolic engineering. These safe sweeteners can be exploited as vital food ingredients for development of low-calorie foods with added functional values especially for children, diabetic patients, and weight watchers. PMID:19200114

  14. Prediction of acid lactic-bacteria growth in turkey ham processed by high hydrostatic pressure

    PubMed Central

    Mathias, S.P.; Rosenthal, A.; Gaspar, A.; Aragão, G.M.F.; Slongo-Marcusi, A.

    2013-01-01

    High hydrostatic pressure (HHP) has been investigated and industrially applied to extend shelf life of meat-based products. Traditional ham packaged under microaerophilic conditions may sometimes present high lactic acid bacteria population during refrigerated storage, which limits shelf life due to development of unpleasant odor and greenish and sticky appearance. This study aimed at evaluating the shelf life of turkey ham pressurized at 400 MPa for 15 min and stored at 4, 8 and 12 °C, in comparison to the non pressurized product. The lactic acid bacteria population up to 107 CFU/g of product was set as the criteria to determine the limiting shelf life According to such parameter the pressurized sample achieved a commercial viability within 75 days when stored at 4 °C while the control lasted only 45 days. Predictive microbiology using Gompertz and Baranyi and Roberts models fitted well both for the pressurized and control samples. The results indicated that the high hydrostatic pressure treatment greatly increased the turkey ham commercial viability in comparison to the usual length, by slowing down the growth of microorganisms in the product. PMID:24159279

  15. Analyses of spatial distributions of sulfate-reducing bacteria and their activity in aerobic wastewater biofilms

    Microsoft Academic Search

    Satoshi Okabe; Tsukasa Itoh; Hisashi Satoh; Yoshimasa Watanabe

    1999-01-01

    The vertical distribution of sulfate-reducing bacteria (SRB) in aerobic wastewater biofilms grown on rotating disk reactors was investigated by fluorescent in situ hybridization (FISH) with 16S rRNA-targeted oligonucleotide probes. To correlate the vertical distribution of SRB populations with their activity, the microprofiles of Oâ, HâS, NOâ-, NHâ{sup +}, and pH were measured with microelectrodes. In addition, a cross-evaluation of the

  16. Reverse dot blot hybridization: a useful method for the direct identification of lactic acid bacteria in fermented food.

    PubMed

    Ehrmann, M; Ludwig, W; Schleifer, K H

    1994-04-01

    A rapid method for a reliable and simultaneous identification of different lactic acid bacteria in fermented food has been developed. Various 16S and 23S rRNA-targeted, species-specific oligonucleotides were applied as capture probes in a non-radioactive reverse dot blot hybridization. A simple and fast DNA extraction method in combination with in vitro amplification of rRNA gene fragments enables the direct detection of typical starter organisms without any preceding enrichment or cultivation steps. Various lactic acid bacteria occurring in cheese, yogurt, sausages, sauerkraut and sourdough could be identified at the species level within 1 day. PMID:8181717

  17. Diversity and abundance of aerobic and anaerobic ammonium-oxidizing bacteria in freshwater sediments of the Xinyi River (China)

    Microsoft Academic Search

    Ying Zhang; Xiao-Hong Ruan; Toine J. M. Smits; Mike S. M. Jetten; Markus C. Schmid

    2007-01-01

    Here we report on the biodiversity and abundance of aerobic and anaerobic ammonium-oxidizing bacteria in sediment samples from the Xinyi River, Jinagsu Province (China). The biodiversity of aerobic ammonium-oxidizing bacteria in the sediment was assessed using the amoA gene as functional marker. The retrieved amoA clones were affiliated to environmental sequences from freshwater habitats. The closest cultivated relative was Nitrosomonas

  18. Current status and emerging role of glutathione in food grade lactic acid bacteria

    PubMed Central

    2012-01-01

    Lactic acid bacteria (LAB) have taken centre stage in perspectives of modern fermented food industry and probiotic based therapeutics. These bacteria encounter various stress conditions during industrial processing or in the gastrointestinal environment. Such conditions are overcome by complex molecular assemblies capable of synthesizing and/or metabolizing molecules that play a specific role in stress adaptation. Thiols are important class of molecules which contribute towards stress management in cell. Glutathione, a low molecular weight thiol antioxidant distributed widely in eukaryotes and Gram negative organisms, is present sporadically in Gram positive bacteria. However, new insights on its occurrence and role in the latter group are coming to light. Some LAB and closely related Gram positive organisms are proposed to possess glutathione synthesis and/or utilization machinery. Also, supplementation of glutathione in food grade LAB is gaining attention for its role in stress protection and as a nutrient and sulfur source. Owing to the immense benefits of glutathione, its release by probiotic bacteria could also find important applications in health improvement. This review presents our current understanding about the status of glutathione and its role as an exogenously added molecule in food grade LAB and closely related organisms. PMID:22920585

  19. Probiotic properties of non-conventional lactic acid bacteria: immunomodulation by Oenococcus oeni.

    PubMed

    Foligné, Benoît; Dewulf, Joëlle; Breton, Jérôme; Claisse, Olivier; Lonvaud-Funel, Aline; Pot, Bruno

    2010-06-15

    The widely used probiotic bacteria belong to the genera Lactobacillus and Bifidobacterium and have in most cases been isolated from the human gastrointestinal tract. However, other "less conventional" bacteria, from allochthonous or extremophilic origin, sharing similar structural or functional features, may also confer specific health benefits to a host. Firstly, we explored the in vitro immuno-modulatory or immune-stimulatory activities of 25 wine lactic acid bacteria belonging to Oenococcus oeni and Pediococcus parvulus. While cytokines released by peripheral blood mononuclear cells (PBMCs) stimulated by P. parvulus strains, showed little variation, O. oeni strains induced strain-specific cytokine patterns. Some O. oeni strains were then further analyzed under various conditions for growth, dose and culture medium. In a second phase, we evaluated the oral tolerance and safety of two strains of O. oeni in mice fed a high dose of bacteria for a week. Finally, evidence was gathered on the in vivo anti-inflammatory potential of a selected O. oeni strain using an experimental 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis mouse model. Although results did not match the anti-inflammatory levels obtained with certain conventional probiotics, strain IOEB 9115 significantly lowered colonic injury and alleviated colitis symptoms. The 'natural' tolerance towards acid, ethanol, and phenolic compounds of O. oeni strains combined with a measureable immunomodulatory potential, suggest a possible use of selected strains isolated from wine as live probiotics. PMID:20452078

  20. Current status and emerging role of glutathione in food grade lactic acid bacteria.

    PubMed

    Pophaly, Sarang Dilip; Singh, Rameshwar; Pophaly, Saurabh Dilip; Kaushik, Jai K; Tomar, Sudhir Kumar

    2012-01-01

    Lactic acid bacteria (LAB) have taken centre stage in perspectives of modern fermented food industry and probiotic based therapeutics. These bacteria encounter various stress conditions during industrial processing or in the gastrointestinal environment. Such conditions are overcome by complex molecular assemblies capable of synthesizing and/or metabolizing molecules that play a specific role in stress adaptation. Thiols are important class of molecules which contribute towards stress management in cell. Glutathione, a low molecular weight thiol antioxidant distributed widely in eukaryotes and Gram negative organisms, is present sporadically in Gram positive bacteria. However, new insights on its occurrence and role in the latter group are coming to light. Some LAB and closely related Gram positive organisms are proposed to possess glutathione synthesis and/or utilization machinery. Also, supplementation of glutathione in food grade LAB is gaining attention for its role in stress protection and as a nutrient and sulfur source. Owing to the immense benefits of glutathione, its release by probiotic bacteria could also find important applications in health improvement. This review presents our current understanding about the status of glutathione and its role as an exogenously added molecule in food grade LAB and closely related organisms. PMID:22920585

  1. Zebrafish gut colonization by mCherry-labelled lactic acid bacteria.

    PubMed

    Russo, Pasquale; Iturria, Iñaki; Mohedano, Maria Luz; Caggianiello, Graziano; Rainieri, Sandra; Fiocco, Daniela; Angel Pardo, Miguel; López, Paloma; Spano, Giuseppe

    2015-04-01

    A critical feature of probiotic microorganisms is their ability to colonize the intestine of the host. Although the microbial potential to adhere to the human gut lumen has been investigated in in vitro models, there is still much to discover about their in vivo behaviour. Zebrafish is a vertebrate model that is being widely used to investigate various biological processes shared with humans. In this work, we report on the use of the zebrafish model to investigate the in vivo colonization ability of previously characterized probiotic lactic acid bacteria. Lactobacillus plantarum Lp90, L. plantarum B2 and Lactobacillus fermentum PBCC11.5 were fluorescently tagged by transfer of the pRCR12 plasmid, which encodes the mCherry protein and which was constructed in this work. The recombinant bacteria were used to infect germ-free zebrafish larvae. After removal of bacteria, the colonization ability of the strains was monitored until 3 days post-infection by using a fluorescence stereomicroscope. The results indicated differential adhesion capabilities among the strains. Interestingly, a displacement of bacteria from the medium to the posterior intestinal tract was observed as a function of time that suggested a transient colonization by probiotics. Based on fluorescence observation, L. plantarum strains exhibited a more robust adhesion capability. In conclusion, the use of pRCR12 plasmid for labelling Lactobacillus strains provides a powerful and very efficient tool to monitor the in vivo colonization in zebrafish larvae and to investigate the adhesion ability of probiotic microorganisms. PMID:25586576

  2. Genome Analysis of Food Grade Lactic Acid-Producing Bacteria: From Basics to Applications

    PubMed Central

    Mayo, B; van Sinderen, D; Ventura, M

    2008-01-01

    Whole-genome sequencing has revolutionized and accelerated scientific research that aims to study the genetics, biochemistry and molecular biology of bacteria. Lactic acid-producing bacteria, which include lactic acid bacteria (LAB) and bifidobacteria, are typically Gram-positive, catalase-negative organisms, which occupy a wide range of natural plant- and animal-associated environments. LAB species are frequently involved in the transformation of perishable raw materials into more stable, pleasant, palatable and safe fermented food products. LAB and bifidobacteria are also found among the resident microbiota of the gastrointestinal and/or genitourinary tracts of vertebrates, where they are believed to exert health-promoting effects. At present, the genomes of more than 20 LAB and bifidobacterial species have been completely sequenced. Their genome content reflects its specific metabolism, physiology, biosynthetic capabilities, and adaptability to varying conditions and environments. The typical LAB/bifidobacterial genome is relatively small (from 1.7 to 3.3 Mb) and thus harbors a limited assortment of genes (from around 1,600 to over 3,000). These small genomes code for a broad array of transporters for efficient carbon and nitrogen assimilation from the nutritionally-rich niches they usually inhabit, and specify a rather limited range of biosynthetic and degrading capabilities. The variation in the number of genes suggests that the genome evolution of each of these bacterial groups involved the processes of extensive gene loss from their particular ancestor, diversification of certain common biological activities through gene duplication, and acquisition of key functions via horizontal gene transfer. The availability of genome sequences is expected to revolutionize the exploitation of the metabolic potential of LAB and bifidobacteria, improving their use in bioprocessing and their utilization in biotechnological and health-related applications. PMID:19440514

  3. Inhibition of Escherichia coli O157:H7 and Salmonella enterica on spinach and identification of antimicrobial substances produced by a commercial Lactic Acid Bacteria food safety intervention.

    PubMed

    Cálix-Lara, Thelma F; Rajendran, Mahitha; Talcott, Stephen T; Smith, Stephen B; Miller, Rhonda K; Castillo, Alejandro; Sturino, Joseph M; Taylor, T Matthew

    2014-04-01

    The microbiological safety of fresh produce is of concern for the U.S. food supply. Members of the Lactic Acid Bacteria (LAB) have been reported to antagonize pathogens by competing for nutrients and by secretion of substances with antimicrobial activity, including organic acids, peroxides, and antimicrobial polypeptides. The objectives of this research were to: (i) determine the capacity of a commercial LAB food antimicrobial to inhibit Escherichia coli O157:H7 and Salmonella enterica on spinach leaf surfaces, and (ii) identify antimicrobial substances produced in vitro by the LAB comprising the food antimicrobial. Pathogens were inoculated on freshly harvested spinach, followed by application of the LAB antimicrobial. Treated spinach was aerobically incubated up to 12 days at 7 °C and surviving pathogens enumerated via selective/differential plating. l-Lactic acid and a bacteriocin-like inhibitory substance (BLIS) were detected and quantified from cell-free fermentates obtained from LAB-inoculated liquid microbiological medium. Application of 8.0 log10 CFU/g LAB produced significant (p < 0.05) reductions in E. coli O157:H7 and Salmonella populations on spinach of 1.6 and 1.9 log10 CFU/g, respectively. It was concluded the LAB antimicrobial inhibited foodborne pathogens on spinach during refrigerated storage, likely the result of the production of metabolites with antimicrobial activity. PMID:24290643

  4. Horizontal gene transfer amongst probiotic lactic acid bacteria and other intestinal microbiota: what are the possibilities? A review

    Microsoft Academic Search

    Carol A. van Reenen; Leon M. T. Dicks

    2011-01-01

    Probiotics are live cultures, usually lactic acid bacteria, which are ingested to promote a healthy gastrointestinal tract.\\u000a These organisms require certain traits to survive and compete in this niche, but these traits may be transferred to other\\u000a microbiota in the gastrointestinal tract (GIT). Similarly, virulence factors from pathogens may be acquired by probiotic strains.\\u000a Bacteria have developed a plethora of

  5. Scarce Evidence of Yogurt Lactic Acid Bacteria in Human Feces after Daily Yogurt Consumption by Healthy Volunteers

    Microsoft Academic Search

    Rosa del Campo; Daniel Bravo; Rafael Canton; Patricia Ruiz-Garbajosa; R. Garcia-Albiach; Alejandra Montesi-Libois; Francisco-Javier Yuste; Victor Abraira; Fernando Baquero

    2005-01-01

    In a double-blind prospective study including 114 healthy young volunteers, the presence in human feces of the yogurt organisms Lactobacillus delbrueckii and Streptococcus thermophilus after repeated yogurt consump- tion (15 days) was analyzed by culture, specific PCR, and DNA hybridization of total fecal DNA. Detection of yogurt lactic acid bacteria in total fecal DNA by bacterial culture and PCR assay

  6. Dynamics of lactic acid bacteria populations in Rioja wines by PCR-DGGE, comparison with culture-dependent methods.

    PubMed

    González-Arenzana, Lucía; López, Rosa; Santamaría, Pilar; López-Alfaro, Isabel

    2013-08-01

    Lactic acid bacteria populations of red wine samples from industrial fermentations, including two different vinification methods were studied. For this investigation, polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis was employed to supplement previous results that were obtained by culture-dependent methods. PCR-DGGE was aimed to study two targeted genes, 16S ribosomal DNA (rDNA) and rpoB, and the results were useful to evaluate the microbial populations in wine samples. Moreover, an improvement of a detection limit determined so far for DGGE analysis was obtained with the method described in this study, what made possible to identify lactic acid bacteria populations below 10(1) colony-forming unit/mL. The species Oenococcus oeni was the most frequently detected bacterium, but identifications close to species Oenococcus kitaharae and Lactococcus lactis that are not often found in wine were firstly identified in samples of this research. PCR-DGGE allowed to detect 9 out of 11 lactic acid bacteria species identified in this study (nine by PCR-16S rDNA/DGGE and four by PCR-rpoB/DGGE), while five species were detected using the modified de Man, Rogosa and Sharpe agar. Therefore, the two methods were demonstrated to be complementary. This finding suggests that analysis of the lactic acid bacteria population structure in wine should be carried out using both culture-dependent and culture-independent techniques with more than one primer pair. PMID:23685477

  7. The rapid identification of lactic acid bacteria present in Chilean winemaking processes using culture-independent analysis.

    PubMed

    Ilabaca, Carolina; Jara, Carla; Romero, Jaime

    2014-01-01

    A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of 16S ribosomal RNA (rRNA) genes was developed to identify lactic acid bacteria (LAB) that are commonly present in winemaking processes (Oenococcus, Pediococcus, Lactobacillus, and Leuconostoc). This culture-independent approach revealed the presence of Oenococcus in the spontaneous malolactic fermentation in industrial Chilean wines. PMID:25419200

  8. Influence of Lactic Acid Bacteria on Longevity of Caenorhabditis elegans and Host Defense against Salmonella enterica Serovar Enteritidis

    Microsoft Academic Search

    Takanori Ikeda; Chikako Yasui; Kaori Hoshino; Kentaro Arikawa; Yoshikazu Nishikawa

    2007-01-01

    This study aimed to develop a convenient model to investigate the senescence of host defenses and the influence of food and nutrition. A small soil nematode, Caenorhabditis elegans, was grown for 3 days from hatching on a lawn of Escherichia coli OP50 as the normal food source, and subsequently some of the nematodes were fed lactic acid bacteria (LAB). The

  9. Study of some of the mechanisms involved in the prevention against Salmonella enteritidis serovar Typhimurium infection by lactic acid bacteria

    Microsoft Academic Search

    Nadia Gobbato; Carolina Maldonado Galdeano; Gabriela Perdigón

    2008-01-01

    The possible mechanism exerted by different lactic acid bacteria (LAB) in the protection against Salmonella enteritidis serovar Typhimurium (S. typhimurium) infection was determined. LAB was administered to BALB\\/c mice, and the animals were subsequently challenged with S.typhimurium. The inhibition of the translocation of S. typhimurium in the liver was correlated with a decrease in cellular apoptosis determined in slices from

  10. Lactic Acid Bacteria Isolated from Indigenous Fermented Bamboo Products of Arunachal Pradesh in India and Their Functionality

    Microsoft Academic Search

    Buddhiman Tamang; Jyoti P. Tamang

    2009-01-01

    Ekung, eup and hirring are some common indigenous fermented bamboo products of Northeast India. We have isolated, characterized, and identified the predominant lactic acid bacteria (LAB) from 44 samples of ekung, eup, and hirring and studied their technological properties. The phenotypic characterizations of LAB isolates were based on physiological, biochemical tests and API kits, and were identified as Lactobacillus plantarum,

  11. Phenotypic and genotypic identification of lactic acid bacteria isolated from ethnic fermented bamboo tender shoots of North East India

    Microsoft Academic Search

    Buddhiman Tamang; Jyoti P. Tamang; Ulrich Schillinger; Charles M. A. P. Franz; Michael Gores; Wilhelm H. Holzapfel

    2008-01-01

    Mesu, soidon, soibum and soijim are ethnic fermented bamboo tender shoot products prepared by the people in North East India. Microbiological analysis of mesu, soidon, soibum and soijim showed the population dominated by lactic acid bacteria (LAB) ranging up to 108 cfu g?1. The phenotypic characterisation of predominant LAB isolated from the fermented bamboo shoot products was based on general morphology,

  12. In Situ Production of Exopolysaccharides during Sourdough Fermentation by Cereal and Intestinal Isolates of Lactic Acid Bacteria

    Microsoft Academic Search

    Markus Tieking; Maher Korakli; Matthias A. Ehrmann; Michael G. Ganzle; Rudi F. Vogel

    2003-01-01

    EPS formed by lactobacilli in situ during sourdough fermentation may replace hydrocolloids currently used as texturizing, antistaling, or prebiotic additives in bread production. In this study, a screening of >100 strains of cereal-associated and intestinal lactic acid bacteria was performed for the production of exopolysaccharides (EPS) from sucrose. Fifteen strains produced fructan, and four strains produced glucan. It was remarkable

  13. Use of Hydrolysates from Yellowfin Tuna ( Thunnus albacares ) Heads as a Complex Nitrogen Source for Lactic Acid Bacteria

    Microsoft Academic Search

    Reza Safari; Ali Motamedzadegan; Mahmoudreza Ovissipour; Joe Mack Regenstein; Asbjorn Gildberg; Barbara Rasco

    Two different peptones obtained by enzymatic hydrolysis of yellowfin tuna (Thunnus albacares) head waste have been shown to be effective in promoting the growth of lactic acid bacteria (Lactobacillus bulgaricus Persian Type Culture Collection (PTCC) 1332, Lactobacillus acidophilus PTCC 1643, Lactobacillus casei PTCC 1608, Lactobacillus delbrukii PTCC 1333, Lactobacillus plantarum PTCC 1058, Lactococcus lactis PTCC 1336, and Lactobacillus sakei PTCC

  14. Effect of Quaternary Ammonium Compounds on Activity of Lactic Acid Starter Bacteria in Milk and Cheese1

    Microsoft Academic Search

    D. D. Miller; P. R. Elliker

    1951-01-01

    The increased application of quaternary ammonium compounds (QAC) for dairy sanitation purposes has stimulated interest in the effect of various con- centrations of these compounds on the growth of lactic acid bacteria in milk. The problem is important from the standpoint of attempts to prevent souring of milk or to reduce bacterial counts prior to delivery to the dairy plant.

  15. Utilization of Echium amoenum Extract as a Growth Medium for the Production of Organic Acids by Selected Lactic Acid Bacteria

    Microsoft Academic Search

    Forough Jahandideh; Seyed Mohammad Mousavi; Seyed Hadi Razavi

    Gol-gavzaban (Echium amoenum Fisch. & Mey.) is an indigenous herbal plant, related to the Boraginaceae family, cultivated historically in Iran. In this study, the suitability of Echium extract as a raw material for production of fermented juice by four strains of lactic acid bacteria (Lactobacillus paracasei, Lactobacillus acidophilus, Lactobacillus plantarum, and Lactobacillus delbrueckii) was examined. Echium extract was inoculated with

  16. Isolation, identification and changes in the composition of lactic acid bacteria during the malting of two different barley cultivars

    Microsoft Academic Search

    C. Booysen; L. M. T. Dicks; I. Meijering; A. Ackermann

    2002-01-01

    Malt has a complex microbial population, which changes as the malting process commences. Little is known about the proliferation of lactic acid bacteria (LAB) in each of the malting phases. In this study, we determined the number of LAB present in the different phases of malting with Clipper and Prisma barley cultivars. The strains were identified to species level by

  17. Comparative study of the inhibitory effects of wine polyphenols on the growth of enological lactic acid bacteria

    Microsoft Academic Search

    Almudena García-Ruiz; M. Victoria Moreno-Arribas; Pedro J. Martín-Álvarez; Begoña Bartolomé

    2011-01-01

    This paper reports a comparative study of the inhibitory potential of 18 phenolic compounds, including hydroxybenzoic acids and their derivatives, hydroxycinnamic acids, phenolic alcohols and other related compounds, stilbenes, flavan-3-ols and flavonols, on different lactic acid bacteria (LAB) strains of the species Oenococcus oeni, Lactobacillus hilgardii and Pediococcus pentosaceus isolated from wine. In general, flavonols and stilbenes showed the greatest

  18. Emerging roles of lactic acid bacteria in protection against colorectal cancer

    PubMed Central

    Zhong, Li; Zhang, Xufei; Covasa, Mihai

    2014-01-01

    Colorectal cancer (CRC) is the third leading cause of cancer deaths worldwide and the fourth most common cancer diagnosed among men and women in the United States. Considering the risk factors of CRC, dietary therapy has become one of the most effective approaches in reducing CRC morbidity and mortality. The use of probiotics is increasing in popularity for both the prevention and treatment of a variety of diseases. As the most common types of microbes used as probiotics, lactic acid bacteria (LAB) are comprised of an ecologically diverse group of microorganisms united by formation of lactic acid as the primary metabolite of sugar metabolism. LAB have been successfully used in managing diarrhea, food allergies, and inflammatory bowel disease. LAB also demonstrated a host of properties in preventing colorectal cancer development by inhibiting initiation or progression through multiple pathways. In this review, we discuss recent insights into cellular and molecular mechanisms of LAB in CRC prevention including apoptosis, antioxidant DNA damages, immune responses, and epigenetics. The emerging experimental findings from clinical trials as well as the proposed mechanisms of gut microbiota in carcinogenesis will also be briefly discussed. PMID:24976724

  19. Recent investigations and updated criteria for the assessment of antibiotic resistance in food lactic acid bacteria.

    PubMed

    Clementi, Francesca; Aquilanti, Lucia

    2011-12-01

    The worldwide use, and misuse, of antibiotics for about sixty years in the so-called antibiotic era, has been estimated in some one to ten million tons, a relevant part of which destined for non-therapeutic purposes such as growth promoting treatments for livestock or crop protection. As highly adaptable organisms, bacteria have reacted to this dramatic change in their environment by developing several well-known mechanisms of antibiotic resistance and are becoming increasingly resistant to conventional antibiotics. In recent years, commensal bacteria have become a cause of concern since they may act as reservoirs for the antibiotic resistance genes found in human pathogens. In particular, the food chain has been considered the main route for the introduction of animal and environment associated antibiotic resistant bacteria into the human gastrointestinal tract (GIT) where these genes may be transferred to pathogenic and opportunistic bacteria. As fundamental microbial communities in a large variety of fermented foods and feed, the anaerobe facultative, aerotolerant lactic acid bacteria (LAB) are likely to play a pivotal role in the resistance gene exchange occurring in the environment, food, feed and animal and human GIT. Therefore their antibiotic resistance features and their genetic basis have recently received increasing attention. The present article summarises the results of the latest studies on the most typical genera belonging to the low G + C branch of LAB. The evolution of the criteria established by European regulatory bodies to ensure a safe use of microorganisms in food and feed, including the assessment of their antibiotic resistance is also reviewed. PMID:21515393

  20. Interaction between lactic acid bacteria and yeasts in sour-dough using a rheofermentometer.

    PubMed

    Gobbetti, M; Corsetti, A; Rossi, J

    1995-11-01

    Rheofermentometer assays were used to characterize the leavening of sour-doughs produced using species of lactic acid bacteria (LAB) and yeasts, alone or in combination. Saccharomyces cerevisiae 141 produced the most CO2 and ethanol whereas S. exiguus M14 and Lactobacillus brevis subsp. lindneri CB1 contributed poorly to leavening and gave sour-doughs without porosity. In comparison with that seen in sour-dough produced with yeast alone, yeast fermentation with heterofermentative LAB present was faster whereas that with homofermentative LAB (L. plantarum DC400, L. farciminis CF3) present was slower and produced more CO2. Combining L. brevis subsp. lindneri CB1 with S. cerevisiae 141 decreased bacterial cell numbers and souring activity. However, addition of fructose to the sour-dough overcame these problems as well as activating S. cerevisiae 141. PMID:24415009

  1. [Antioxidant properties of lactic acid bacteria--probiotic and yogurt strains].

    PubMed

    Uskova, M A; Kravchenko, L V

    2009-01-01

    Antioxidant properties of 14 strains of lactic acid bacteria were evaluated in vitro using FRAP assay, inhibition of luminol oxidation in Hb-H2O2 system and inhibition of NADPH-Fe2+ induced microsomal lipid peroxidation. All strains demonstrated high reducing properties, but only L. casei spp. (including L. casei 114001) and L. fermentum ME-3 revealed pronounced ability to suppress oxidation of luminol (by 43-65,8%) and microsomal lipid peroxidation (by 57,9-89,5%). Either L. casei 114001 (10(8) CFU suspended in physiological solution) or fermented dairy drink containing equivalent amount of L. casei 114001 were daily administered orally to male Wistar rats. Antioxidant capacity of blood plasma, liver and intestines of animals elevated while MDA content in blood plasma decreased. PMID:19514338

  2. Evaluation of the probiotic characteristics of newly isolated lactic acid bacteria.

    PubMed

    Aswathy, Ravindran Girija; Ismail, Bindhumol; John, Rojan Pappy; Nampoothiri, Kesavan Madhavan

    2008-12-01

    Lactic acid bacteria were isolated from fermented vegetables, sour dough, milk products, sheep and human excreta. The newly isolated cultures were evaluated for a number of probiotic characteristics like bile salt resistance, salt tolerance in general, survival in low pH, hydrophobicity of the cell surface, resistance to low phenol concentration, antimicrobial activity and susceptibility pattern against vancomycin and erythromycin. The selected cultures were further screened for their ability to produce the nutraceticals such as folic acid and exopolysaccharide (EPS). Two potent isolates, CB2 (from cabbage) and SD2 (from sour dough) were found to produce both extracellular and intracellular folate. One of the isolates from yogurt (MC-1) and the one from whey (W3) produced significant amount of EPS with a maximum production of 8.79 +/- 0.05 g/l by MC-1. PMID:18592412

  3. Cell wall anchoring of the Streptococcus pyogenes M6 protein in various lactic acid bacteria.

    PubMed Central

    Piard, J C; Hautefort, I; Fischetti, V A; Ehrlich, S D; Fons, M; Gruss, A

    1997-01-01

    The M6 protein from Streptococcus pyogenes is the best-characterized member of a family of cell envelope-associated proteins. Based on the observation that the C-terminal sorting signals of these proteins can drive cell wall anchoring of heterologous unanchored proteins, we have cloned and expressed the emm6 structural gene for the M6 protein in various lactic acid bacteria (LAB). The emm6 gene was successfully expressed from lactococcal promoters in several Lactococcus lactis strains, an animal-colonizing Lactobacillus fermentum strain, Lactobacillus sake, and Streptococcus salivarius subsp. thermophilus. The M6 protein was efficiently anchored to the cell wall in all strains tested. In lactobacilli, essentially all detectable M6 protein was cell wall associated. These results suggest the feasibility of using the C-terminal anchor moiety of M6 for protein surface display in LAB. PMID:9139932

  4. Traditional Indian fermented foods: a rich source of lactic acid bacteria.

    PubMed

    Satish Kumar, R; Kanmani, P; Yuvaraj, N; Paari, K A; Pattukumar, V; Arul, V

    2013-06-01

    This review describes the diversity of Indian fermented food and its significance as a potential source of lactic acid bacteria (LAB). Fermented foods consumed in India are categorized based upon their base material. Fermented foods such as dahi, gundruk, sinki, iniziangsang, iromba, fermented rai, kanjika and handua were reported to have significant medicinal properties. Some fermented products such as koozh, dahi and kanjika are consumed unknowingly as, probiotic drinks, by local people. There are very few reports regarding isolation of LAB from Indian fermented foods available in the past; however, due to growing consciousness about potential health benefits of LAB, we now have scores of reports in this field. There is an abundant opportunity available for food microbiologists to explore the Indian fermented foods for the isolation of new LAB strains for their potential role in probiotic research. PMID:23181843

  5. Numbers, diversity, and morphological characteristics of aerobic, chemoheterotrophic bacteria in deep subsurface sediments from a site in South Carolina

    Microsoft Academic Search

    David L. Balkwill

    1989-01-01

    The aerobic, chemoheterotrophic bacteria indigenous to deep aquifers and other subsurface sediments (depths to 265 m) at a site in South Carolina were characterized by direct microscopy, enumeration of viable cells, analysis of colony morphologies on plates, and analysis of cell morphologies of isolated strains. Substantial numbers of viable bacteria (1010\\/g) were present in all transmissive, aquifer sediments, and their

  6. Screening lactic acid bacteria from swine origins for multistrain probiotics based on in vitro functional properties.

    PubMed

    Guo, Xiao-Hua; Kim, Jong-Man; Nam, Hyang-Mi; Park, Shin-Young; Kim, Jae-Myung

    2010-08-01

    Lactic acid bacteria originated from swine feces and intestines were selected for potential probiotics based on their bile-salt resistance, low pH tolerance, potential adhesion to epithelial cells and especially functional properties, including production of antimicrobial substances, bile-salt hydrolase (BSH) and amylolytic activity. Results showed 7 isolates with antimicrobial activity, 5 with BSH activity and 3 with amylolytic activity were preliminarily selected from 485 lactic acid bacteria based on their highest potential with functional properties in vitro. The 15 isolates were further assayed on the essential characteristics as potential probiotics. All isolates were fully tolerant to 0.3% bile salts and 11 of them were able to resist pH 3 for 3 h without loss of viable cells. The eleven isolates were then evaluated on their adhesion capability. Wide variation in the hydrophobic character and specific adhesion efficiency was observed and three isolates G1-1, G22-2 and G8-5, with respective antimicrobial, BSH and amylolytic activities were finally selected. In addition, the three isolates were compatible in the coexistence assay. Isolate G1-1 was identified as Lactobacillus salivarius by API system and a 16S rRNA gene sequence analysis. Both G8-5 and G22-2 showed the closest homology to Lactobacillus reuteri according to their 16S rRNA gene sequences (99%). From the study, the three Lactobacilli strains were shown to share the functional properties necessary for probiotics use in animal additives. Their compatibility with respective in vitro activities was expected to show enhanced in vivo efficacy after combination for multistrain probiotics use. PMID:20304081

  7. Antioxidative activities of soymilk fermented with lactic acid bacteria and bifidobacteria.

    PubMed

    Wang, Yi-Chieh; Yu, Roch-Chui; Chou, Cheng-Chun

    2006-04-01

    To further the goal of developing a probiotic dietary adjunct using soymilk, soymilk is fermented with lactic acid bacteria (Lactobacillus acidophilus CCRC 14079 or Streptococcus thermophilus CCRC 14085) and bifidobacteria (Bifidobacterium infantis CCRC 14633 or Bifidobacterium longum B6) individually, and in conjunction. We investigate several antioxidative activities including the inhibition of ascorbate autoxidation, the scavenging effect of superoxide anion radicals and hydrogen peroxide, and the reducing activity exerted by different varieties of fermented soymilks. In addition, the effect of spray-drying and freeze-drying on changes in antioxidative activity is examined. We find that in fermented soymilk both the inhibition of ascorbate autoxidation, and the reducing activity and scavenging effect of superoxide anion radicals varied with the starters used, but nevertheless are significantly higher than those found in unfermented soymilk. In general, antioxidative activity in soymilk fermented with lactic acid bacteria and bifidobacteria simultaneously is significantly higher (P < 0.05) than that fermented with either individually. Moreover, antioxidative activity increases as the fermentation period is extended. However, unfermented soymilk shows an H2O2-scavenging effect, while there is no scavenging effect except for the accumulation of H2O2 in fermented soymilk. Finally, we find that freeze-drying causes a significantly lesser (P < 0.05) reduction in the antioxidative activity of soymilk than does spray-drying. Irrespective of the drying method and the starters used for fermentation. The antioxidative activity of fermented soymilk reduces after drying yet remains higher than that of dried unfermented soymilk. PMID:16942996

  8. Antimicrobial action of hydrolyzed chitosan against spoilage yeasts and lactic acid bacteria of fermented vegetables.

    PubMed

    Savard, Tony; Beaulieu, Carole; Boucher, Isabelle; Champagne, Claude P

    2002-05-01

    The antimicrobial properties of various chitosan-lactate polymers (ranging from 0.5 to 1.2 MDa in molecular weight) against two yeasts isolated from fermented vegetables and against three lactic acid bacteria from a mixed starter for sauerkraut on methylene blue agar (MBA) and in vegetable juice medium (VJM) were investigated. Chitosan-lactate reduced the growth of all microorganisms in solid (MBA) as well as in liquid (VJM) medium. In MBA, a concentration of 5 g/liter was needed to inhibit the growth of Saccharomyces bayanus, while 1 g/liter was sufficient to inhibit the growth of Saccharomyces unisporus. Lactic acid bacteria were also inhibited in this range of concentrations. The low-molecular-weight chitosan-lactate DP3 (0.5 kDa) was most efficient in solid medium (MBA), and inhibitory activities decreased with increasing hydrolysate lengths. In liquid medium (VJM), 0.5 g of chitosan-lactate per liter reduced the growth rates for both yeasts, but 10 g/liter was insufficient to prevent yeast growth. Intermediate-molecular-weight chitosan-lactate (5 kDa) was more efficient than chitosan of low molecular weight. Native chitosan (1.2 MDa) showed no inhibition in either medium. Microscopic examination of S. unisporus Y-42 after treatment with chitosan-lactate DP25 showed agglutination of a refractive substance on the entire cell wall, suggesting an interaction between chitosan and the cell wall. When chitosanase was added to the culture media containing chitosan-lactate, refractive substances could not be observed. PMID:12030295

  9. Influence of bovine lactoferrin on the growth of selected probiotic bacteria under aerobic conditions.

    PubMed

    Chen, Po-Wen; Ku, Yu-We; Chu, Fang-Yi

    2014-10-01

    Bovine lactoferrin (bLf) is a natural glycoprotein, and it shows broad-spectrum antimicrobial activity. However, reports on the influences of bLf on probiotic bacteria have been mixed. We examined the effects of apo-bLf (between 0.25 and 128 mg/mL) on both aerobic and anaerobic cultures of probiotics. We found that bLf had similar effects on the growth of probiotics under aerobic or anaerobic conditions, and that it actively and significantly (at concentrations of >0.25 mg/mL) retarded the growth rate of Bifidobacterium bifidum (ATCC 29521), B. longum (ATCC 15707), B. lactis (BCRC 17394), B. infantis (ATCC 15697), Lactobacillus reuteri (ATCC 23272), L. rhamnosus (ATCC 53103), and L. coryniformis (ATCC 25602) in a dose-dependent manner. Otherwise, minimal inhibitory concentrations (MICs) were 128 or >128 mg/mL against B. bifidum, B. longum, B. lactis, L. reuteri, and L. rhamnosus (ATCC 53103). With regard to MICs, bLf showed at least four-fold lower inhibitory effect on probiotics than on pathogens. Intriguingly, bLf (>0.25 mg/mL) significantly enhanced the growth of Rhamnosus (ATCC 7469) and L. acidophilus (BCRC 14065) by approximately 40-200 %, during their late periods of growth. Supernatants produced from aerobic but not anaerobic cultures of L. acidophilus reduced the growth of Escherichia coli by about 20 %. Thus, bLf displayed a dose-dependent inhibitory effect on the growth of most probiotic strains under either aerobic or anaerobic conditions. An antibacterial supernatant prepared from the aerobic cultures may have significant practical use. PMID:24916115

  10. Phylogenetic and Kinetic Diversity of Aerobic Vinyl Chloride-Assimilating Bacteria from Contaminated Sites

    PubMed Central

    Coleman, Nicholas V.; Mattes, Timothy E.; Gossett, James M.; Spain, Jim C.

    2002-01-01

    Aerobic bacteria that grow on vinyl chloride (VC) have been isolated previously, but their diversity and distribution are largely unknown. It is also unclear whether such bacteria contribute to the natural attenuation of VC at chlorinated-ethene-contaminated sites. We detected aerobic VC biodegradation in 23 of 37 microcosms and enrichments inoculated with samples from various sites. Twelve different bacteria (11 Mycobacterium strains and 1 Nocardioides strain) capable of growth on VC as the sole carbon source were isolated, and 5 representative strains were examined further. All the isolates grew on ethene in addition to VC and contained VC-inducible ethene monooxygenase activity. The Mycobacterium strains (JS60, JS61, JS616, and JS617) all had similar growth yields (5.4 to 6.6 g of protein/mol), maximum specific growth rates (0.17 to 0.23 day?1), and maximum specific substrate utilization rates (9 to 16 nmol/min/mg of protein) with VC. The Nocardioides strain (JS614) had a higher growth yield (10.3 g of protein/mol), growth rate (0.71 day?1), and substrate utilization rate (43 nmol/min/mg of protein) with VC but was much more sensitive to VC starvation. Half-velocity constant (Ks) values for VC were between 0.5 and 3.2 ?M, while Ks values for oxygen ranged from 0.03 to 0.3 mg/liter. Our results indicate that aerobic VC-degrading microorganisms (predominantly Mycobacterium strains) are widely distributed at sites contaminated with chlorinated solvents and are likely to be responsible for the natural attenuation of VC. PMID:12450841

  11. Cytofluorometric detection of wine lactic acid bacteria: application of malolactic fermentation to the monitoring.

    PubMed

    Salma, Mohammad; Rousseaux, Sandrine; Sequeira-Le Grand, Anabelle; Alexandre, Hervé

    2013-01-01

    In this study we report for the first time a rapid, efficient and cost-effective method for the enumeration of lactic acid bacteria (LAB) in wine. Indeed, up to now, detection of LAB in wine, especially red wine, was not possible. Wines contain debris that cannot be separated from bacteria using flow cytometry (FCM). Furthermore, the dyes tested in previous reports did not allow an efficient staining of bacteria. Using FCM and a combination of BOX/PI dyes, we were able to count bacteria in wines. The study was performed in wine inoculated with Oenococcus oeni (10(6) CFU ml(-1)) stained with either FDA or BOX/PI and analyzed by FCM during the malolactic fermentation (MLF). The analysis show a strong correlation between the numbers of BOX/PI-stained cells determined by FCM and the cell numbers determined by plate counts (red wine: R (2) ? 0.97, white wine R (2) ? 0.965). On the other hand, we found that the enumeration of O. oeni labeled with FDA was only possible in white wine (R (2) ? 0.97). Viable yeast and LAB populations can be rapidly discriminated and quantified in simultaneous malolactic-alcoholic wine fermentations using BOX/PI and scatter parameters in a one single measurement. This rapid procedure is therefore a suitable method for monitoring O. oeni populations during winemaking, offers a detection limit of <10(4) CFU ml(-1) and can be considered a useful method for investigating the dynamics of microbial growth in wine and applied for microbiological quality control in wineries. PMID:23080189

  12. Environmental stress response in wine lactic acid bacteria: beyond Bacillus subtilis.

    PubMed

    Spano, G; Massa, S

    2006-01-01

    Lactic acid bacteria (LAB) constitute a heterogeneous group of bacteria that are traditionally used to produce fermented foods. The industrialization of food transformations has increased the economical importance of LAB, as they play a crucial role in the development of the organoleptic and hygienic quality of fermented products. However, the strains selected for industrial purposes, should tolerate adverse conditions encountered in industrial processes, either during starter handling and storage (freeze-drying, freezing, or spray-drying) or during food processing in which abiotic stresses such as heat, cold, acidity, and high concentration of NaCl or ethanol are common. Wine LAB have to deal with several stresses including an acidic pH, a high alcoholic content, non optimal growth temperatures, and growth-inhibitory compounds such as fatty acids and tannins, originated from yeast and bacteria metabolism. Wine LAB have developed several mechanisms to escape or to tolerate wine conditions. They carry out a malolactic fermentation in this stressful environment. In addition to the regulation of the expression of specific genes, bacteria have evolved adaptive networks to face the challenges of a changing environment and to survive under conditions of stress. The so called Global Regulatory Systems control the simultaneous expression of a large number of genes in response to a variety of environmental stress factors. CIRCE sequences able to bind the HrcA repressor, sigma(B) dependent promoters and CtsR regulatory elements have been observed in several genes identified from wine LAB. Improved knowledge of regulators and a better understanding of LAB stress responses could constitute a basis of comparison with the well known model microorganisms, Escherichia coli and Bacillus subtilis. Moreover, it can provide an important insight into improving current industrial starter strains. PMID:16809231

  13. Influence of sodium chloride, pH, and lactic acid bacteria on anaerobic lactic acid utilization during fermented cucumber spoilage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cucumbers are preserved commercially by natural fermentations in 5% to 8% sodium chloride (NaCl) brines. Occasionally, fermented cucumbers spoil after the primary fermentation is complete. This spoilage has been characterized by decreases in lactic acid and a rise in brine pH caused by microbial ins...

  14. Stochastic modelling of Listeria monocytogenes single cell growth in cottage cheese with mesophilic lactic acid bacteria from aroma producing cultures.

    PubMed

    Østergaard, Nina Bjerre; Christiansen, Lasse Engbo; Dalgaard, Paw

    2015-07-01

    A stochastic model was developed for simultaneous growth of low numbers of Listeria monocytogenes and populations of lactic acid bacteria from the aroma producing cultures applied in cottage cheese. During more than two years, different batches of cottage cheese with aroma culture were analysed for pH, lactic acid concentration and initial concentration of lactic acid bacteria. These data and bootstrap sampling were used to represent product variability in the stochastic model. Lag time data were estimated from observed growth data (lactic acid bacteria) and from literature on L. monocytogenes single cells. These lag time data were expressed as relative lag times and included in growth models. A stochastic model was developed from an existing deterministic growth model including the effect of five environmental factors and inter-bacterial interaction [Østergaard, N.B, Eklöw, A and Dalgaard, P. 2014. Modelling the effect of lactic acid bacteria from starter- and aroma culture on growth of Listeria monocytogenes in cottage cheese. International Journal of Food Microbiology. 188, 15-25]. Growth of L. monocytogenes single cells, using lag time distributions corresponding to three different stress levels, was simulated. The simulated growth was subsequently compared to growth of low concentrations (0.4-1.0CFU/g) of L. monocytogenes in cottage cheese, exposed to similar stresses, and in general a good agreement was observed. In addition, growth simulations were performed using population relative lag time distributions for L. monocytogenes as reported in literature. Comparably good predictions were obtained as for the simulations performed using lag time data for individual cells of L. monocytogenes. Therefore, when lag time data for individual cells are not available, it was suggested that relative lag time distributions for L. monocytogenes can be used as a qualified default assumption when simulating growth of low concentrations of L. monocytogenes. PMID:25847186

  15. Diversity of lactic acid bacteria in two Flemish artisan raw milk Gouda-type cheeses.

    PubMed

    Van Hoorde, Koenraad; Verstraete, Tine; Vandamme, Peter; Huys, Geert

    2008-10-01

    PCR-denaturing gradient gel electrophoresis (PCR-DGGE) was used to study the diversity of lactic acid bacteria (LAB) in two Flemish artisan raw milk Gouda-type cheeses. In parallel, conventional culturing was performed. Isolates were identified using (GTG)(5)-PCR and sequence analysis of 16S rRNA and pheS genes. Discriminant analysis revealed some differences in overall LAB diversity between the two batches and between the two cheeses. Within each batch, the diversity of 8- and 12-week-old cheeses was relatively similar. Conventional isolation mainly revealed the presence of Lactobacillus paracasei, Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus rhamnosus and Pediococcus pentosaceus. PCR-DGGE revealed the presence of three species of which no isolates were recovered, i.e. Enterococcus faecalis, Lactobacillus parabuchneri and Lactobacillus gallinarum. Conversely, not all isolated bacteria were detected by PCR-DGGE. We recommend the integrated use of culture-dependent and -independent approaches to maximally encompass the taxonomic spectrum of LAB occurring in Gouda-type and other cheeses. PMID:18721684

  16. GH1-family 6-P-?-glucosidases from human microbiome lactic acid bacteria

    PubMed Central

    Michalska, Karolina; Tan, Kemin; Li, Hui; Hatzos-Skintges, Catherine; Bearden, Jessica; Babnigg, Gyorgy; Joachimiak, Andrzej

    2013-01-01

    In lactic acid bacteria and other bacteria, carbohydrate uptake is mostly governed by phosphoenolpyruvate-dependent phosphotransferase systems (PTSs). PTS-dependent translocation through the cell membrane is coupled with phosphorylation of the incoming sugar. After translocation through the bacterial membrane, the ?-glycosidic bond in 6?-­P-­?-glucoside is cleaved, releasing 6-P-?-glucose and the respective aglycon. This reaction is catalyzed by 6-P-?-glucosidases, which belong to two glycoside hydrolase (GH) families: GH1 and GH4. Here, the high-resolution crystal structures of GH1 6-P-?-glucosidases from Lactobacillus plantarum (LpPbg1) and Streptococcus mutans (SmBgl) and their complexes with ligands are reported. Both enzymes show hydrolytic activity towards 6?-P-?-glucosides. The LpPbg1 structure has been determined in an apo form as well as in a complex with phosphate and a glucose molecule corresponding to the aglycon molecule. The S. mutans homolog contains a sulfate ion in the phosphate-dedicated subcavity. SmBgl was also crystallized in the presence of the reaction product 6-P-?-glucose. For a mutated variant of the S. mutans enzyme (E375Q), the structure of a 6?-P-salicin complex has also been determined. The presence of natural ligands enabled the definition of the structural elements that are responsible for substrate recognition during catalysis. PMID:23519420

  17. Use of selected lactic acid bacteria in the eradication of Helicobacter pylori infection.

    PubMed

    Kim, Jin-Eung; Kim, Min-Soo; Yoon, Yeo-Sang; Chung, Myung-Jun; Yum, Do-Young

    2014-11-01

    Helicobacter pylori is among the major pathogenic bacteria that cause chronic gastritis and peptic ulcer disease and is related to the development of gastric cancer. Several chemicals, including antibiotics, have been used to eradicate H. pylori; however, they do not always curb the infection. Ten representative type strains of lactic acid bacteria (LAB) were screened for antagonism toward H. pylori via inhibition of urease activity. Strains inhibiting the binding of H. pylori to human gastric cell line cells and suppressing H. pylori-induced interleukin-8 (IL-8) production were also screened. Of these, Pediococcus pentosaseus (SL4), which inhibited the adhesion of H. pylori to MKN-45 gastric cancer cells, Bifidobacterium longum (BG7), with urease inhibiting activity, and Lactococcus lactis (SL3), and Enterococcus faecalis (SL5), which suppressed H. pylori-induced IL-8 production within MKN-45 and AGS cells, were selected. In mouse model, these LAB stains in combination significantly suppressed IL-8 levels in serum. Gastric pH also recovered to normal values after the administration of these LAB. These stains effectively suppressed H. pylori viability, although not to the extent of antibiotic treatment. When used as probiotics, LAB may help decrease the occurrence of gastritis and reduce the risk of H. pylori infection without, inducing side effects. PMID:25277407

  18. Probiotic lactic acid bacteria and their potential in the prevention and treatment of allergic diseases

    PubMed Central

    Wróblewska, Paula; Adamczuk, Piotr; Silny, Wojciech

    2014-01-01

    Allergy is one of the most important and very common health problems worldwide. To reduce the proportion of people suffering from allergy, alternative methods of prevention and treatment are sought. The aim of this paper is to present the possibilities of probiotics in the prevention and treatment of allergic diseases. Probiotics are live microorganisms belonging mainly to the lactic acid bacteria. They modify the microflora of the human digestive system, especially the intestinal microflora. Prophylactic administration of probiotics in the early stages of life (naturally in breast milk or milk substitute synthetic compounds) is very important because intestinal microflora plays a huge role in the development of the immune system. Prevention of allergies as early as in the prenatal and postnatal periods provides huge opportunities for inhibiting the growing problem of allergy in emerging and highly developed societies. Effects of probiotic therapy depend on many factors such as the species of the microorganism used, the dose size and characteristics of the bacteria such as viability and capacity of adhesion to the intestinal walls. Authors of several studies showed beneficial effects of probiotics in the perinatal period, infancy, and also in adults in the prevention of atopic dermatitis or allergic rhinitis. Probiotics, due to their immunomodulatory properties and safety of use are a good, natural alternative for the prevention and treatment of many diseases including allergies. It is therefore important to explore the knowledge about their use and to carry out further clinical trials.

  19. The immunomodulatory effects of lactic acid bacteria for improving immune functions and benefits.

    PubMed

    Tsai, Yueh-Ting; Cheng, Po-Ching; Pan, Tzu-Ming

    2012-11-01

    Probiotics have a number of beneficial health effects in humans and animals, such as reducing lactose intolerance symptoms and enhancing the bioavailability of nutrients. Probiotics help regulate intestinal microflora and immunomodulatory properties. Probiotics also decrease the prevalence of allergies in susceptible individuals, inhibit the inflammatory responses in the gut, and have antagonistic effects against intestinal and food-borne pathogens. Bacteria typically colonize the intestinal tract first and then reinforce the host defense systems by inducing generalized mucosal immune responses, including modulation of DC/NK interaction, a balanced T-helper cell response, self-limited inflammatory response, and the secretion of polymeric IgA. A lot of reports showed that lactic acid bacteria (LAB) as Lactobacillus and Bifidobacterium and their fermented products are effective at enhancing innate and adaptive immunity, prevent gastric mucosal lesion development, alleviate allergies, and put up defense against intestinal pathogen infection. In this review paper, we compared the influence of immunomodulatory effects on the function and efficacy of lactobacillus products with different strains. We also discuss the beneficial effects of several LAB strain and its derivative products for human immunity and related diseases. PMID:23001058

  20. Selection of enhanced antimicrobial activity posing lactic acid bacteria characterised by (GTG)5-PCR fingerprinting.

    PubMed

    Šalomskien?, Joana; Abraitien?, Asta; Jonkuvien?, Dovil?; Ma?ionien?, Irena; Repe?kien?, J?rat?

    2015-07-01

    The aim of the study was a detail evaluation of genetic diversity among the lactic acid bacteria (LAB) strains having an advantage of a starter culture in order to select genotypically diverse strains with enhanced antimicrobial effect on some harmfull and pathogenic microorganisms. Antimicrobial activity of LAB was performed by the agar well diffusion method and was examined against the reference strains and foodborne isolates of Bacillus cereus, Listeria monocytogenes, Escherichia coli, Staphylococcus aureus and Salmonella Typhimurium. Antifungal activity was tested against the foodborne isolates of Candida parapsilosis, Debaromyces hansenii, Kluyveromyces marxianus, Pichia guilliermondii, Yarowia lipolytica, Aspergillus brasiliensis, Aspergillus versicolor, Cladosporium herbarum, Penicillium chrysogenum and Scopulariopsis brevicaulis. A total 40 LAB strains representing Lactobacillus (23 strains), Lactococcus (13 strains) and Streptococcus spp. (4 strains) were characterised by repetitive sequence based polymerase chain reaction fingerprinting which generated highly discriminatory profiles, confirmed the identity and revealed high genotypic heterogeneity among the strains. Many of tested LAB demonstrated strong antimicrobial activity specialised against one or few indicator strains. Twelve LAB strains were superior in suppressing growth of the whole complex of pathogenic bacteria and fungi. These results demonstrated that separate taxonomic units offered different possibilities of selection for novel LAB strains could be used as starter cultures enhancing food preservation. PMID:26139877

  1. Identification and functional traits of lactic acid bacteria isolated from Ciauscolo salami produced in Central Italy.

    PubMed

    Federici, Sara; Ciarrocchi, Floriana; Campana, Raffaella; Ciandrini, Eleonora; Blasi, Giuliana; Baffone, Wally

    2014-12-01

    Lactic acid bacteria (LAB) from Ciauscolo salami produced in Marche Region of Central Italy, and LAB strains belonging to our laboratory collection were examined for their capability to survive at low pH and bile, to adhere to Caco-2 cells, and for antibiotic resistance. LAB from Ciauscolo were identified by ARDRA and RAPD-PCR. Our study showed that all LAB strains had good adaptation to gastric juice and moderate tolerance to bile. The adhesiveness was variable among strains but significantly lower in LAB from food. Antibiotic resistance was broadly spread among food strains, with level of resistance exceeding 15% for all the antibiotics tested. The resistance determinants erm(B) and tet(M) were found in nine strains of food origin (21.4%) while tet(L) in one strain of our collection (5%). Our work suggests that fermented foods are valuable sources of bacterial strains with functional traits of intestinal lactobacilli. These bacteria may be further studied for their use in probiotic applications. PMID:25089780

  2. Evaluation of culture media for selective enumeration of bifidobacteria and lactic acid bacteria

    PubMed Central

    Süle, Judit; Kõrösi, Tímea; Hucker, Attila; Varga, László

    2014-01-01

    The purpose of this study was to test the suitability of Transgalactosylated oligosaccharides-mupirocin lithium salt (TOS-MUP) and MRS-clindamycin-ciprofloxacin (MRS-CC) agars, along with several other culture media, for selectively enumerating bifidobacteria and lactic acid bacteria (LAB) species commonly used to make fermented milks. Pure culture suspensions of a total of 13 dairy bacteria strains, belonging to eight species and five genera, were tested for growth capability under various incubation conditions. TOS-MUP agar was successfully used for the selective enumeration of both Bifidobacterium animalis subsp. lactis BB-12 and B. breve M-16 V. MRS-CC agar showed relatively good selectivity for Lactobacillus acidophilus, however, it also promoted the growth of Lb. casei strains. For this reason, MRS-CC agar can only be used as a selective medium for the enumeration of Lb. acidophilus if Lb. casei is not present in a product at levels similar to or exceeding those of Lb. acidophilus. Unlike bifidobacteria and coccus-shaped LAB, all the lactobacilli strains involved in this work were found to grow well in MRS pH 5.4 agar incubated under anaerobiosis at 37 °C for 72 h. Therefore, this method proved to be particularly suitable for the selective enumeration of Lactobacillus spp. PMID:25477939

  3. Microbiological and biochemical profile of cv. Conservolea naturally black olives during controlled fermentation with selected strains of lactic acid bacteria.

    PubMed

    Panagou, Efstathios Z; Schillinger, Ulrich; Franz, Charles M A P; Nychas, George-John E

    2008-04-01

    The effect of controlled fermentation processes on the microbial association and biochemical profile of cv. Conservolea naturally black olives processed by the traditional anaerobic method was studied. The different treatments included (a) inoculation with a commercial starter culture of Lactobacillus pentosus, (b) inoculation with a strain of Lactobacillus plantarum isolated from a fermented cassava product and (c) uninoculated spontaneous process. Microbial growth, pH, titratable acidity, organic acids and volatile compounds were monitored throughout the fermentation. The initial microbiota consisted of Gram-negative bacteria, lactic acid bacteria and yeasts. Inhibition of Gram-negative bacteria was evident in all processes. Both starter cultures were effective in establishing an accelerated fermentation process and reduced the survival period of Gram-negative bacteria by 5 days compared with the spontaneous process, minimizing thus the likelihood of spoilage. Higher acidification of the brines was observed in inoculated processes without any significant difference between the two selected starter cultures (113.5 and 117.6mM for L. plantarum and L. pentosus, respectively). L. pentosus was also determined as the major species present during the whole process of spontaneous olive fermentation. It is characteristic that lactic acid fermentation was also initiated rapidly in the spontaneous process, as the conditions of fermentation, mainly the low salt level (6%, w/v) favored the dominance of lactic acid bacteria over yeasts. Lactic, acetic and propionic were the organic acids detected by HPLC in considerable amounts, whereas citric and malic acids were also present at low levels and degraded completely during the processes. Ethanol, methanol, acetaldehyde, ethyl acetate were the major volatile compounds identified by GC. Their concentrations varied among the different treatments, reflecting varying degrees of microbial activity in the brines. The results obtained from this study could help the Greek table olive industry to improve the existing processing schemes in order to increase product consistency and quality expanding the international market for naturally black olives. PMID:18206777

  4. Selection of potential probiotic lactic acid bacteria from fermented olives by in vitro tests.

    PubMed

    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 ?-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 to assess their technological performance as novel probiotic starters. PMID:23200662

  5. Natural Lactic Acid Bacteria Population and Silage Fermentation of Whole-crop Wheat.

    PubMed

    Ni, Kuikui; Wang, Yanping; Cai, Yimin; Pang, Huili

    2015-08-01

    Winter wheat is a suitable crop to be ensiled for animal feed and China has the largest planting area of this crop in the world. During the ensiling process, lactic acid bacteria (LAB) play the most important role in the fermentation. We investigated the natural population of LAB in whole-crop wheat (WCW) and examined the quality of whole-crop wheat silage (WCWS) with and without LAB inoculants. Two Lactobacillus plantarum subsp. plantarum strains, Zhengzhou University 1 (ZZU 1) selected from corn and forage and grass 1 (FG 1) from a commercial inoculant, were used as additives. The silages inoculated with LAB strains (ZZU 1 and FG 1) were better preserved than the control, with lower pH values (3.5 and 3.6, respectively) (p<0.05) and higher contents of lactic acid (37.5 and 34.0 g/kg of fresh matter (FM), respectively) (p<0.05) than the control. Sixty LAB strains were isolated from fresh material and WCWS without any LAB inoculation. These LAB strains were divided into the following four genera and six species based on their phenotypic, biochemical and phylogenetic characteristics: Leuconostoc pseudomesenteroides, Leuconostoc citreum, Weissella cibaria, Lactococcus lactis subsp. lactis, Lactobacillus buchneri, and Lactobacillus plantarum subsp. plantarum. However, the prevalent LAB, which was predominantly heterofermentative (66.7%), consisted of Leuconostoc pseudomesenteroides, Leuconostoc citreum, Weissella cibaria, and Lactobacillus buchneri. This study revealed that most of isolated LAB strains from control WCWS were heterofermentative and could not grow well at low pH condition; the selective inoculants of Lactobacillus strains, especially ZZU 1, could improve WCWS quality significantly. PMID:26104520

  6. Viability of lactic acid bacteria and bifidobacteria in fermented soymilk after drying, subsequent rehydration and storage.

    PubMed

    Wang, Yi-Chieh; Yu, Roch-Chui; Chou, Cheng-Chun

    2004-06-01

    To develop a probiotic dietary adjunct, soymilk fermented with various combinations of lactic acid bacteria (Streptococcus thermophilus and Lactobacillus acidophilus) and bifidobacteria (Bifidobacterium longum and Bifidobacterium infantis) was subjected to freeze-drying and spray-drying. Survival of the starter organisms during the drying process, subsequent rehydration at different temperatures and during a 4-month period of storage under different storage conditions was examined. After freeze-drying, lactic acid bacteria and bifidobacteria exhibited a survival percent of 46.2-75.1% and 43.2-51.9%, respectively, higher than that noted after spray-drying. Regardless of the drying condition, S. thermophilus showed a higher percentage of survival than L. acidophilus, while B. longum survived better than B. infantis. Further study with soymilk fermented with S. thermophilus and B. longum revealed that the freeze-dried and spray-dried fermented soymilk rehydrated at 35-50 degrees C and 20 degrees C, respectively, was optimum for the recovery of the starter organisms. Both S. thermophilus and B. longum survived better in the freeze-dried than the spray-dried fermented soymilk during storage. A higher percent of survival was also noted for both the starter organisms when the dried fermented soymilk was stored at 4 degrees C than 25 degrees C. Holding the dried fermented soymilk in the laminated pouch enabled S. thermophilus and B. longum to exhibit a higher percentage of survival than in the deoxidant- and desiccant-containing glass or polyester (PET) bottle. Among all the packaging materials and storage temperatures tested, starter organisms were most stable in the dried fermented soymilk held in laminated pouch and stored at 4 degrees C. Under this storage condition, S. thermophilus and B. longum showed a survival percentage of 51.1% and 68.8%, respectively, in the freeze-dried fermented soymilk after 4 months of storage. Meanwhile, S. thermophilus and B. infantis in the spray-dried fermented soymilk showed a survival percent of 29.5% and 57.7%, respectively. PMID:15135959

  7. Tina wooden vat biofilm: a safe and highly efficient lactic acid bacteria delivering system in PDO Ragusano cheese making.

    PubMed

    Lortal, Sylvie; Di Blasi, Annalisa; Madec, Marie-Noëlle; Pediliggieri, Concetta; Tuminello, Laura; Tanguy, Gaëlle; Fauquant, Jacques; Lecuona, Yohan; Campo, Patrizia; Carpino, Stefania; Licitra, Giuseppe

    2009-06-01

    In the Sicilian PDO Ragusano cheese making, raw milk is placed in a wooden vat called a Tina. As no starter is added, lactic acid is produced by milk flora and flora released from the Tina biofilm. The aim of this work was to assess the safety and efficiency of this natural inoculation system. From 15 Tinas' biofilms, bacteria total counts varied from 10(3) to 10(6) CFU/cm(2), with the predominance of thermophilic lactic acid bacteria. Low counts of yeasts and moulds were found in a few Tinas. Salmonella, Listeria monocytogenes, Escherichia coli O157:H7 were totally absent, as assessed by conventional plating and the Bax detection system after enrichment, highlighting the safety of the system. From four Tinas out of the 15, micropieces of wood were observed by confocal and scanning electron microscopy. The biofilm entrapped in a matrix covered almost entirely the surface of the wood. Polysaccharides were detected in the four Tinas. In three of the latter, cocci were predominant in the ecosystem whereas in the other one, cocci, bacilli, yeasts and moulds were observed. Fifty litres of microfiltrated milk (<10 CFU/mL) were poured in the four Tinas for 10 min of contact. Enumeration of lactic acid bacteria, yeasts and enterococci were performed in the milk after contact. Depending on the Tina, from 5.10(4) to 10(6) CFU/mL of Streptococcus thermophilus were released into the milk, and from 10(4) to 10(5) CFU/mL of thermophilic lactobacilli. Spontaneous acidification after contact confirmed the high efficiency of biofilm lactic acid bacteria delivery. PMID:19361876

  8. Proteolysis by Sourdough Lactic Acid Bacteria: Effects on Wheat Flour Protein Fractions and Gliadin Peptides Involved in Human Cereal Intolerance

    Microsoft Academic Search

    Raffaella Di Cagno; Maria De Angelis; Paola Lavermicocca; Massimo De Vincenzi; Claudio Giovannini; Michele Faccia; Marco Gobbetti

    2002-01-01

    Sourdough lactic acid bacteria were preliminarily screened for proteolytic activity by using a digest of albumin and globulin polypeptides as a substrate. Based on their hydrolysis profile patterns, Lactobacillus alimentarius 15M, Lactobacillus brevis 14G, Lactobacillus sanfranciscensis 7A, and Lactobacillus hilgardii 51B were selected and used in sourdough fermentation. A fractionated method of protein extraction and subsequent two-dimensional electrophoresis were used

  9. Interaction between Lactic Acid Bacteria and Mycobacterium bovis in Ethiopian Fermented Milk: Insight into the Fate of M. bovis?

    PubMed Central

    Mariam, Solomon H.

    2009-01-01

    Mycobacterium bovis causes tuberculosis in animals and humans. Infected cows can transmit the bacillus to humans via milk. Milk also contains lactic acid bacteria (LAB). LAB isolated from milk were put in milk cultures together with spiked M. bovis. Different LAB had different abilities to reduce M. bovis counts, as M. bovis was undetectable in some while it persisted in two of the cultures. PMID:19168654

  10. Microbiological study of lactic acid bacteria in kefir grains by culture-dependent and culture-independent methods

    Microsoft Academic Search

    Hsi-Chia Chen; Sheng-Yao Wang; Ming-Ju Chen

    2008-01-01

    Lactic acid bacteria (LAB) in different original kefir grains were first assessed using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) by a culture-dependent way, and were further confirmed by DNA sequencing techniques. Results indicated that a combined method of cultivation with PCR-DGGE and subsequent DNA sequencing could successfully identify four LAB strains from three kefir grains from Taiwan (named Hsinchu,

  11. Application of PCR-DGGE for the identification of lactic acid bacteria in acitve dry wine yeasts

    Microsoft Academic Search

    Cristina Giusto; Dagmara Medrala; Giuseppe Comi; Marisa Manzano

    2007-01-01

    In this work a Polymerase Chain Reaction (PCR)-Denaturing Gradient Gel Electrophoresis (DGGE) protocol was used to identify\\u000a the Lactic Acid Bacteria (LAB) contaminants in enological active dry yeasts routinely used in the wine production. The method\\u000a is based on the PCR amplification of a DNA fragment from the region V1 of 16S rDNA gene followed by a DGGE technique. The

  12. Phylogenetic group- and species-specific oligonucleotide probes for single-cell detection of lactic acid bacteria in oral biofilms

    Microsoft Academic Search

    Beatrice Quevedo; Elin Giertsen; Vincent Zijnge; Helga Lüthi-Schaller; Bernhard Guggenheim; Thomas Thurnheer; Rudolf Gmür

    2011-01-01

    BACKGROUND: The purpose of this study was to design and evaluate fluorescent in situ hybridization (FISH) probes for the single-cell detection and enumeration of lactic acid bacteria, in particular organisms belonging to the major phylogenetic groups and species of oral lactobacilli and to Abiotrophia\\/Granulicatella. RESULTS: As lactobacilli are known for notorious resistance to probe penetration, probe-specific assay protocols were experimentally

  13. Antimould activity of sourdough lactic acid bacteria: identification of a mixture of organic acids produced by Lactobacillus sanfrancisco CB1

    Microsoft Academic Search

    A. Corsetti; M. Gobbetti; J. Rossi; P. Damiani

    1998-01-01

    Sourdough lactic acid bacteria, cultivated in wheat flour hydrolysate, produced antimould compounds. The antimould activity\\u000a varied greatly among the strains and was mainly detected within obligately heterofermentative Lactobacillus spp. Among these, Lb. sanfrancisco CB1 had the largest spectrum. It inhibited moulds related to bread spoilage such as Fusarium, Penicillium, Aspergillus and Monilia. A mixture of acetic, caproic, formic, propionic, butyric

  14. Glutamate dehydrogenase activity: a major criterion for the selection of flavour-producing lactic acid bacteria strains

    Microsoft Academic Search

    Catherine Tanous; Agnieszka Kieronczyk; Sandra Helinck; Emilie Chambellon; Mireille Yvon

    2002-01-01

    Lactic acid bacteria (LAB) have the enzyme potential to transform amino acids into aroma compounds that contribute greatly to cheese flavour. Generally, amino acid conversion by LAB is limited by their low production of a-ketoglutarate since this a-ketoacid is essential for the first step of the conversion. Indeed, we have demonstrated that adding exogenous a-ketoglutarate to cheese curd, as well

  15. Improvement of protein production in lactic acid bacteria using 5?-untranslated leader sequence of slpA from Lactobacillus acidophilus

    Microsoft Academic Search

    Junya Narita; Saori Ishida; Kenji Okano; Sakurako Kimura; Hideki Fukuda; Akihiko Kondo

    2006-01-01

    The 5?-untranslated leader sequence (UTLS) of the slpA gene from Lactobacillus acidophilus contributes to mRNA stabilization by producing a 5? stem and loop structure, and a high-level expression system for the lactic acid bacteria was developed using the UTLS in this study. A plasmid, which expresses ?-amylase under the control of the ldh promoter, was constructed by integrating the core

  16. Variations in the energy metabolism of biotechnologically relevant heterofermentative lactic acid bacteria during growth on sugars and organic acids

    Microsoft Academic Search

    T. Zaunmüller; M. Eichert; H. Richter; G. Unden

    2006-01-01

    Heterofermentative lactic acid bacteria (LAB) such as Leuconostoc, Oenococcus, and Lactobacillus strains ferment pentoses by the phosphoketolase pathway. The extra NAD(P)H, which is produced during growth on hexoses, is transferred to acetyl-CoA, yielding ethanol. Ethanol fermentation represents the limiting step in hexose fermentation, therefore, part of the extra NAD(P)H is used to produce erythritol and glycerol. Fructose, pyruvate, citrate, and

  17. Ecology and technological capability of lactic acid bacteria isolated during Grillo grape vinification in the Marsala production area

    Microsoft Academic Search

    Nicola Francesca; Luca Settanni; Ciro Sannino; Maria Aponte; Giancarlo Moschetti

    2011-01-01

    Grapes of the “Grillo” variety, used to produce Marsala wine, were harvested from five vineyards with different climatic and\\u000a agronomic parameters, in order to obtain a first mapping of lactic acid bacteria (LAB) inhabiting the production area. Marsala\\u000a base wine production was followed at a large-scale, and also two experimental vinifications, with different lysozyme and SO2 concentrations and in combination,

  18. Phylogenetic Diversity of Lactic Acid Bacteria Associated with Paddy Rice Silage as Determined by 16S Ribosomal DNA Analysis

    Microsoft Academic Search

    Saïd Ennahar; Yimin Cai; Yasuhito Fujita

    2003-01-01

    A total of 161 low-GC-content gram-positive bacteria isolated from whole-crop paddy rice silage were classified and subjected to phenotypic and genetic analyses. Based on morphological and biochemical char- acters, these presumptive lactic acid bacterium (LAB) isolates were divided into 10 groups that included members of the genera Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Pediococcus, and Weissella. Analysis of the 16S ribosomal DNA

  19. Effect of high pressure treatment on starter bacteria and spoilage yeasts in fresh lactic curd cheese of bovine milk

    Microsoft Academic Search

    H. Daryaei; M. J. Coventry; C. Versteeg; F. Sherkat

    2008-01-01

    The effect of high pressure treatment on the inactivation of starter bacteria and spoilage yeasts in a commercially manufactured fresh lactic curd cheese was investigated. Fresh cheeses made from pasteurised bovine milk using a commercial Lactococcus starter preparation were vacuum-packaged and subjected to high pressure treatment within the range of 200 to 600 MPa for 5 min at ambient temperature (?22 °C), and

  20. Development and quality of a Brazilian semi-hard goat cheese (coalho) with added probiotic lactic acid bacteria.

    PubMed

    Garcia, Estefânia Fernandes; de Oliveira, Maria Elieidy Gomes; Queiroga, Rita de Cássia Ramos Do Egypto; Machado, Tamires Alcântara Dourado; de Souza, Evandro Leite

    2012-12-01

    The effects of the addition of different strains of lactic acid bacteria on different quality parameters of a Brazilian goat semi-hard cheese (coalho) were assessed during 7 days of storage (10°C) as follows: Control, Lactobacillus lactis subsp. lactis and L. lactis subsp. cremoris (standard); C2, L. acidophilus; C3, L. paracasei; C4, Bifidobacterium lactis; and C5, L. acidophilus, L. paracasei and B. lactis. There were no differences for the proteolysis index and depth of proteolysis among the assessed cheeses. The cheeses presented increase in hardness, gumminess and chewiness during the storage. Regarding the ability to melt, all evaluated cheeses showed a reduction in diameter. Cheeses presented high luminosity with predominance of the yellow component; and number of lactic bacteria greater than 10?-10? cfu/g during the 7 days of storage. C5 had better sensory scores in the acceptance test, purchase intention and preference ranking test. Coalho goat cheese could be a potential carrier of probiotic lactic acid bacteria. PMID:22574688

  1. Isolation and identification of microorganisms including lactic acid bacteria and their use in microbial deacidification of wines from domestic vineyards.

    PubMed

    Drozdz, Iwona; Makarewicz, Malgorzata; Tuszy?ski, Tadeusz

    2013-01-01

    The aim of this study was to identify various bacteria isolated from grapes and their wines. Additionally we investigated the capacity of lactic acid bacteria for microbiological deacidification of wines produced in Poland. We have identified Oenococcus oeni, Lactobacillus acidophilus and Lactobacillus delbrueckii. During the microbial deacidification process, we observed decreases of total acidity and increases of volatile acidity, with statistically significant changes noted for O. oeni in Marechal Foch and Seyval Blanc, and for Lb. acidophilus in Frontenac. On the other hand, a statistically significant increase in pH was observed in Marechal Foch and Seyval Blanc following deacidification by O. oeni. PMID:24459842

  2. [Use of real-time PCR for quantitative assessment of lactic acid bacteria and bifidobacteria in dairy products].

    PubMed

    Zelenaia, L B; Kovalenko, N K; Oblap, R V; Hovak, N B; Golubets, R A

    2012-01-01

    Composition of lactic acid bacteria and bifidobacteria in raw milk and home-made milk products has been analyzed using real-time PCR (quantitative PCR) with genus-specific primers to Enterococcus, Lactobacillus and Bifidobacteria. Bacteria belonging to these genera have been revealed in all samples analyzed (milk, sour cream, cottage cheese). It has been shown that the representatives of Enterococcus and Lactobacillus genera dominated in the samples analyzed (10(3)-10(7) genome equivalent/ml (mg)). The largest number of these microorganisms (10(7) genome equivalent/mg) has been detected in cottage cheese. PMID:22545439

  3. Disinfectant and antibiotic resistance of lactic acid bacteria isolated from the food industry.

    PubMed

    Sidhu, M S; Langsrud, S; Holck, A

    2001-01-01

    Quaternary ammonium compounds (QACs) are widely used as disinfectant in medical and food environments. There is a growing concern about the increasing incidence of disinfectant-resistant microorganisms from food. Disinfectant-resistant lactic acid bacteria (LAB) may survive disinfection and cause spoilage problems. Moreover, resistant LAB may potentially act as a reservoir for resistance genes. A total number of 320 LAB from food industry and meat were screened for resistance to the QAC benzalkonium chloride (BC). Out of 320 strains, five strains (1.5%) were considered to be resistant and 56 (17.5%) were tolerant to BC. The resistant strains were isolated from food processing equipment after disinfection. The resistant, tolerant, and some sensitive control bacteria were examined for susceptibility to 18 different antibiotics, disinfectants, and dyes using disc agar diffusion test and microdilution method. Little systematic cross-resistance between BC and any of the antimicrobial agents tested were detected except for gentamycin and chlorhexidine. A BC-tolerant strain was much easier to adapt to higher levels of BC as compared to a BC-sensitive strain. No known gram-positive QAC resistance genes (qacA/B, qacC, qacG, and qacH) were detected in the BC-resistant strains. Identification to species level of the BC-resistant isolates was carried out by comparative analysis of 16S-rDNA sequencing. In conclusion, resistance to BC is not frequent in LAB isolated from food and food environments. Resistance may occur after exposure to BC. The BC resistant isolates showed no cross-resistance with other antimicrobial compounds, except for gentamycin and chlorhexidine. Nevertheless, BC-resistant LAB may be isolated after disinfection and may contribute to the dissemination of resistance. PMID:11310806

  4. Characterization of lactic acid bacteria from naturally-fermented Manzanilla Aloreña green table olives.

    PubMed

    Abriouel, Hikmate; Benomar, Nabil; Cobo, Antonio; Caballero, Natacha; Fernández Fuentes, Miguel Ángel; Pérez-Pulido, Rubén; Gálvez, Antonio

    2012-12-01

    Manzanilla Aloreña (or Aloreña) table olives are naturally fermented traditional green olives with a denomination of protection (DOP). The aim of this study was to search for lactic acid bacteria (LAB) with technological properties of interest for possible inclusion in a starter or protective culture preparation or also as probiotics. A collection of 144 LAB obtained from Aloreña green table olives naturally-fermented by four small-medium enterprises (SMEs) from Málaga (Spain), including lactobacilli (81.94%), leuconostocs (10.42%) and pediococci (7.64%) were studied. REP-PCR clustering and further identification of strains by sequencing of phes and rpo genes revealed that all lactobacilli from the different SMEs were Lactobacillus pentosus. Pediococci were identified as Pediococcus parvulus (SME1) and leuconostocs as Leuconostoc pseudomesenteroides (SME1 and SME4). Genotyping revealed that strains were not clonally related and exhibited a considerable degree of genomic diversity specially for lactobacilli and also for leuconostocs. Some strains exhibit useful technological properties such as production of antimicrobial substances active against pathogenic bacteria such as Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Streptococcus mutans and Salmonella enterica, utilization of raffinose and stachyose, production of bile salt hydrolase, phytase and haeme-dependent catalase activities, growth at 10 °C and in the presence of 6.5% NaCl, good acidifying capacity and also resistance to freezing. However, none of the isolates showed protease or amylase activity, and also did not exhibit biogenic amine production from histidine, ornithine, cysteine or tyrosine. On the basis of data obtained, selected strains with potential traits were tested for their survival at low pH and their tolerance to bile salts, and the survival capacity demonstrated by some of the analysed strains are encouraging to further study their potential as probiotics. PMID:22986194

  5. Antimicrobial activity of bacteriocin-producing lactic acid bacteria isolated from cheeses and yogurts

    PubMed Central

    2012-01-01

    The biopreservation of foods using bacteriocinogenic lactic acid bacteria (LAB) isolated directly from foods is an innovative approach. The objectives of this study were to isolate and identify bacteriocinogenic LAB from various cheeses and yogurts and evaluate their antimicrobial effects on selected spoilage and pathogenic microorganisms in vitro as well as on a food commodity. LAB were isolated using MRS and M17 media. The agar diffusion bioassay was used to screen for bacteriocin or bacteriocin-like substances (BLS) producing LAB using Lactobacillus sakei and Listeria innocua as indicator organisms. Out of 138 LAB isolates, 28 were found to inhibit these bacteria and were identified as strains of Enterococcus faecium, Streptococcus thermophilus, Lactobacillus casei and Lactobacillus sakei subsp. sakei using 16S rRNA gene sequencing. Eight isolates were tested for antimicrobial activity at 5°C and 20°C against L. innocua, Escherichia coli, Bacillus cereus, Pseudomonas fluorescens, Erwinia carotovora, and Leuconostoc mesenteroides subsp. mesenteroides using the agar diffusion bioassay, and also against Penicillium expansum, Botrytis cinerea and Monilinia frucitcola using the microdilution plate method. The effect of selected LAB strains on L. innocua inoculated onto fresh-cut onions was also investigated. Twenty percent of our isolates produced BLS inhibiting the growth of L. innocua and/or Lact. sakei. Organic acids and/or H2O2 produced by LAB and not the BLS had strong antimicrobial effects on all microorganisms tested with the exception of E. coli. Ent. faecium, Strep. thermophilus and Lact. casei effectively inhibited the growth of natural microflora and L. innocua inoculated onto fresh-cut onions. Bacteriocinogenic LAB present in cheeses and yogurts may have potential to be used as biopreservatives in foods. PMID:22963659

  6. Gassericin A: a circular bacteriocin produced by lactic acid bacteria Lactobacillus gasseri.

    PubMed

    Pandey, Neha; Malik, R K; Kaushik, J K; Singroha, Garima

    2013-11-01

    During the recent years extensive efforts have been made to find out bacteriocins from lactic acid bacteria (LAB) active against various food spoilage and pathogenic bacteria, and superior stabilities against heat treatments and pH variations. Bacteriocins isolated from LAB have been grouped into four classes. Circular bacteriocins which were earlier grouped among the four groups of bacteriocins, have recently been proposed to be classified into a different class, making it class V bacteriocins. Circular bacteriocins are special molecules, whose precursors must be post translationally modified to join the N to C termini with a head-to-tail peptide bond. Cyclization appears to make them less susceptible to proteolytic cleavage, high temperature and pH, and, therefore, provides enhanced stability as compared to linear bacteriocins. The advantages of circularization are also reflected by the fact that a significant number of macrocyclic natural products have found pharmaceutical applications. Circular bacteriocins were unknown two decades ago, and even to date, only a few circular bacteriocins from a diverse group of Gram positive organisms have been reported. The first example of a circular bacteriocin was enterocin AS-48, produced by Enterococcus faecalis AS-48. Gassereccin A, produced by Lactobacillus gasseri LA39, Reutericin 6 produced by Lactobacillus reuteri LA6 and Circularin A, produced by Clostridium beijerinickii ATCC 25,752, are further examples of this group of antimicrobial peptides. In the present scenario, Gassericin A can be an important tool in the food preservation owing to its properties of high pH and temperature tolerance and the fact that it is produced by LAB L. gasseri, whose many strains are proven probiotic. PMID:23712477

  7. Control of spoilage fungi by protective lactic acid bacteria displaying probiotic properties.

    PubMed

    Varsha, Kontham Kulangara; Priya, Sulochana; Devendra, Leena; Nampoothiri, Kesavan Madhavan

    2014-04-01

    Thirty-six lactic acid bacteria belong to Lactococcus, Lactobacillus, Enterococcus, and Pediococcus were isolated, and the spectrum of antifungal activity was verified against Fusarium oxysporum (KACC 42109), Aspergillus niger (KACC 42589), Fusarium moniliforme (KACC 08141), Penicillium chrysogenum (NII 08137), and the yeast Candida albicans (MTCC 3017). Three isolates, identified as Pediococcus pentosaceus (TG2), Lactobacillus casei (DY2), and Lactococcus (BSN) were selected further, and their antifungal compounds were identified by ESI-MS and HPLC analysis as a range of carboxylic acids along with some unidentified, higher molecular weight compounds. An attempt to check out the shelf life extension of wheat bread without fungal spoilage was performed by fermenting the dough with the Lactococcus isolate. Apart from growth in low pH and tolerance to bile salts, probiotic potential of these three isolates was further substantiated by in vitro screening methods that include transit tolerance to the conditions in the upper human gastrointestinal tract and bacterial adhesion capacity to human intestinal cell lines. PMID:24532445

  8. A survey of the lactic acid bacteria isolated from Serbian artisanal dairy product kajmak.

    PubMed

    Jokovic, Natasa; Nikolic, Milica; Begovic, Jelena; Jovcic, Branko; Savic, Dragisa; Topisirovic, Ljubisa

    2008-10-31

    Kajmak is an artisanal Serbian dairy product made by fermentation of milk fat. Overall, 374 bacterial isolates were collected from six kajmak samples of different ages produced in the households located in distinct regions of Serbia. In order to identify lactic acid bacteria present in chosen samples of kajmak, total 349 Gram-positive and catalase-negative isolates were analyzed. The recognition of isolates was performed by phenotypic characterization followed by molecular identification using (GTG)(5)-PCR and sequence analysis of 16S rRNA gene. Leuconostoc mesenteroides and Enterococcus faecium were the most frequently isolated species from kajmak samples. In contrast, leuconostocs and enterococci were found in BGMK3 and BGMK1 kajmak respectively, only after using enrichment technique for isolation suggesting they are present in low numbers in these kajmaks. Lactococcus lactis, Lactococcus raffinolactis and Lactococcus garvieae were also found in those samples but in lower proportion. Results showed that Lactobacillus plantarum, Lb. paracasei and Lb. kefiri were the most frequently isolated Lactobacillus species in analyzed kajmaks. PMID:18775578

  9. Cholesterol assimilation by lactic acid bacteria and bifidobacteria isolated from the human gut.

    PubMed

    Pereira, Dora I A; Gibson, Glenn R

    2002-09-01

    The objective of this study was to evaluate the effect of human gut-derived lactic acid bacteria and bifidobacteria on cholesterol levels in vitro. Continuous cultures inoculated with fecal material from healthy human volunteers with media supplemented with cholesterol and bile acids were used to enrich for potential cholesterol assimilators among the indigenous bacterial populations. Seven potential probiotics were found: Lactobacillus fermentum strains F53 and KC5b, Bifidobacterium infantis ATCC 15697, Streptococcus bovis ATCC 43143, Enterococcus durans DSM 20633, Enterococcus gallinarum, and Enterococcus faecalis. A comparative evaluation regarding the in vitro cholesterol reduction abilities of these strains along with commercial probiotics was undertaken. The degree of acid and bile tolerance of strains was also evaluated. The human isolate L. fermentum KC5b was able to maintain viability for 2 h at pH 2 and to grow in a medium with 4,000 mg of bile acids per liter. This strain was also able to remove a maximum of 14.8 mg of cholesterol per g (dry weight) of cells from the culture medium and therefore was regarded as a candidate probiotic. PMID:12200334

  10. Screening for glycosidase activities of lactic acid bacteria as a biotechnological tool in oenology.

    PubMed

    Pérez-Martín, Fátima; Seseña, Susana; Izquierdo, Pedro Miguel; Martín, Raúl; Palop, María Llanos

    2012-04-01

    The aim of this study was to evaluate the ability from a number of lactic acid bacteria isolated from different sources to produce glycosidase enzymes. Representative isolates (225) from clusters obtained after genotyping, using randomly amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) analysis, of 1,464 isolates, were screened for ?-D-glucosidase activity. Thirty-five of them were selected for subsequent analysis. These strains were able to hydrolyze ?-D-glucopyranoside, ?-D-xylopyranoside and ?-L-arabinofuranoside although ?-D-glucosidase activity was the predominant activity for 22 of the selected strains. Only some of them did so with ?-L-rhamnopyranoside. All of these were from wine samples and were identified as belonging to the Oenococcus oeni species using Amplification and Restriction Analysis of 16S-rRNA gene (16S-ARDRA). When the influence of pH, temperature and ethanol or sugars content on ?-D-glucosidase activity was assayed, a strain-dependent response was observed. The ?-D-glucosidase activity occurred in both whole and sonicated cells but not in the supernatants from cultures or obtained after cell sonication. Strains 10, 17, 21, and 23 retained the most ?-D-glucosidase activity when they were assayed at the conditions of temperature, pH, ethanol and sugar content used in winemaking. These results suggest that these strains could be used as a source of glycosidase enzymes for use in winemaking. PMID:22805923

  11. Oenococcus alcoholitolerans sp. nov., a lactic acid bacteria isolated from cachaça and ethanol fermentation processes.

    PubMed

    Badotti, Fernanda; Moreira, Ana Paula B; Tonon, Luciane A Chimetto; de Lucena, Brígida T Luckwu; Gomes, Fátima de Cássia O; Kruger, Ricardo; Thompson, Cristiane C; de Morais, Marcos Antonio; Rosa, Carlos A; Thompson, Fabiano L

    2014-12-01

    Four strains of lactic acid bacteria isolated from cachaça and alcohol fermentation vats in Brazil were characterised in order to determine their taxonomic position. Phylogenetic analysis revealed that they belong to the genus Oenococcus and should be distinguished from their closest neighbours. The 16S rRNA gene sequence similarity against the type strains of the other two species of the genus was below 94.76 % (Oenococcus kitaharae) and 94.62 % (Oenococcus oeni). The phylogeny based on pheS gene sequences also confirmed the position of the new taxon. DNA-DNA hybridizations based on in silico genome-to-genome comparison, Average Amino Acid Identity, Average Nucleotide Identity and Karlin genomic signature confirmed the novelty of the taxon. Distinctive phenotypic characteristics are the ability to metabolise sucrose but not trehalose. The name Oenococcus alcoholitolerans sp. nov. is proposed for this taxon, with the type strain UFRJ-M7.2.18(T) ( = CBAS474(T) = LMG27599(T)). In addition, we have determined a draft genome sequence of the type strain. PMID:25315101

  12. Risk assessment of genetically modified lactic acid bacteria using the concept of substantial equivalence.

    PubMed

    LeBlanc, Jean Guy; Van Sinderen, Douwe; Hugenholtz, Jeroen; Piard, Jean-Christophe; Sesma, Fernando; de Giori, Graciela Savoy

    2010-12-01

    The use of food-grade microorganisms such as lactic acid bacteria (LAB) is one of the most promising methods for delivering health promoting compounds. Since it is not always possible to obtain strains that have the ability to produce specific compounds naturally or that produce them in sufficient quantities to obtain physiological responses, genetic modifications can be performed to improve their output. The objective of this study was to evaluate if previously studied genetically modified LAB (GM-LAB), with proven in vivo beneficial effects, are just as safe as the progenitor strain from which they were derived. Mice received an elevated concentration of different GM-LAB or the native parental strain from which they were derived during a prolonged period of time, and different health parameters were evaluated. Similar growth rates, hematological values, and other physiological parameters were obtained in the animals that received the GM-LAB compared to those that were fed with the native strain. These results demonstrate that the GM-LAB used in this study are just as safe as the native strains from which they were derived and thus merit further studies to include them into the food chain. PMID:20449592

  13. Lactic acid bacteria and yeasts involved in the fermentation ofamabere amaruranu, a Kenyan fermented milk

    PubMed Central

    Nyambane, Bitutu; Thari, William M; Wangoh, John; Njage, Patrick M K

    2014-01-01

    Indigenous fermented milk products contain microbiota composed of technologically important species and strains which are gradually getting lost with new technologies. We investigated the microbial diversity inamabere amaruranu, a traditionally fermented milk product from Kenya. Sixteen samples of the product from different containers were obtained. One hundred and twenty isolates of lactic acid bacteria (LAB) and 67 strains of yeasts were identified using API 50 CH and API 20 C AUX identification kits, respectively. The average pH of all the traditional fermented samples was 4.00 ± 0.93. Lactobacilli, yeasts, and molds as well asEnterobacteriaceae counts from the plastic containers were significantly higher (P < 0.05) than those from gourd.Enterobacteriaceae were below 1.00 ± 1.11 log10 cfu/mL in products from the gourds and 2.17 ± 1.92 log10 cfu/mL from the plastic containers. The LAB species were identified asStreptococcus thermophilus (25%),Lactobacillus plantarum (20%), andLeuconostoc mesenteroides (20%). The predominant yeasts wereSaccharomyces cerevisiae (25%),Trichosporum mucoides (15%),Candida famata (10%), andCandida albicans (10%). The type of vessel used for fermentation had no significant influence on the type of isolated and identified species. The diverse mixture of LAB and yeasts microflora forms a potential consortium for further product innovation inamabere amaruranu and other fermented milk products. PMID:25493187

  14. Monitoring psychrotrophic lactic acid bacteria contamination in a ready-to-eat vegetable salad production environment.

    PubMed

    Pothakos, Vasileios; Snauwaert, Cindy; De Vos, Paul; Huys, Geert; Devlieghere, Frank

    2014-08-18

    A study monitoring lactic acid bacteria contamination was conducted in a company producing fresh, minimally processed, packaged and ready-to-eat (RTE) vegetable salads (stored at 4°C) in order to investigate the reason for high psychrotrophic LAB levels in the products at the end of shelf-life. Initially, high microbial counts exceeding the established psychrotrophic thresholds (>10(7)-10(8)CFU/g) and spoilage manifestations before the end of the shelf-life (7days) occurred in products containing an assortment of sliced and diced vegetables, but within a one year period these spoilage defects became prevalent in the entire processing plant. Environmental sampling and microbiological analyses of the raw materials and final products throughout the manufacturing process highlighted the presence of high numbers of Leuconostoc spp. in halved and unseeded, fresh sweet bell peppers provided by the supplier. A combination of two DNA fingerprinting techniques facilitated the assessment of the species diversity of LAB present in the processing environment along with the critical point of their introduction in the production facility. Probably through air mediation and surface adhesion, mainly members of the strictly psychrotrophic species Leuconostoc gelidum subsp. gasicomitatum and L. gelidum subsp. gelidum were responsible for the cross-contamination of every vegetable handled within the plant. PMID:24927398

  15. Evidence of Two Functionally Distinct Ornithine Decarboxylation Systems in Lactic Acid Bacteria

    PubMed Central

    Romano, Andrea; Trip, Hein; Lonvaud-Funel, Aline; Lolkema, Juke S.

    2012-01-01

    Biogenic amines are low-molecular-weight organic bases whose presence in food can result in health problems. The biosynthesis of biogenic amines in fermented foods mostly proceeds through amino acid decarboxylation carried out by lactic acid bacteria (LAB), but not all systems leading to biogenic amine production by LAB have been thoroughly characterized. Here, putative ornithine decarboxylation pathways consisting of a putative ornithine decarboxylase and an amino acid transporter were identified in LAB by strain collection screening and database searches. The decarboxylases were produced in heterologous hosts and purified and characterized in vitro, whereas transporters were heterologously expressed in Lactococcus lactis and functionally characterized in vivo. Amino acid decarboxylation by whole cells of the original hosts was determined as well. We concluded that two distinct types of ornithine decarboxylation systems exist in LAB. One is composed of an ornithine decarboxylase coupled to an ornithine/putrescine transmembrane exchanger. Their combined activities results in the extracellular release of putrescine. This typical amino acid decarboxylation system is present in only a few LAB strains and may contribute to metabolic energy production and/or pH homeostasis. The second system is widespread among LAB. It is composed of a decarboxylase active on ornithine and l-2,4-diaminobutyric acid (DABA) and a transporter that mediates unidirectional transport of ornithine into the cytoplasm. Diamines that result from this second system are retained within the cytosol. PMID:22247134

  16. Genetic and technological characterisation of vineyard- and winery-associated lactic acid bacteria.

    PubMed

    Nisiotou, Aspasia A; Dourou, Dimitra; Filippousi, Maria-Evangelia; Diamantea, Ellie; Fragkoulis, Petros; Tassou, Chryssoula; Banilas, Georgios

    2015-01-01

    Vineyard- and winery-associated lactic acid bacteria (LAB) from two major PDO regions in Greece, Peza and Nemea, were surveyed. LAB were isolated from grapes, fermenting musts, and winery tanks performing spontaneous malolactic fermentations (MLF). Higher population density and species richness were detected in Nemea than in Peza vineyards and on grapes than in fermenting musts. Pediococcus pentosaceus and Lactobacillus graminis were the most abundant LAB on grapes, while Lactobacillus plantarum dominated in fermenting musts from both regions. No particular structure of Lactobacillus plantarum populations according to the region of origin was observed, and strain distribution seems random. LAB species diversity in winery tanks differed significantly from that in vineyard samples, consisting principally of Oenococcus oeni. Different strains were analysed as per their enological characteristics and the ability to produce biogenic amines (BAs). Winery-associated species showed higher resistance to low pH, ethanol, SO2, and CuSO4 than vineyard-associated isolates. The frequency of BA-producing strains was relatively low but not negligible, considering that certain winery-associated Lactobacillus hilgardii strains were able to produce BAs. Present results show the necessity of controlling the MLF by selected starters in order to avoid BA accumulation in wine. PMID:25866789

  17. Genotypic and phenotypic characterization of lactic acid bacteria isolated from Italian ryegrass silage.

    PubMed

    Tohno, Masanori; Kobayashi, Hisami; Nomura, Masaru; Kitahara, Maki; Ohkuma, Moriya; Uegaki, Ryuichi; Cai, Yimin

    2012-02-01

    Twenty-three lactic acid bacteria (LAB) isolated from three cultivars (Akiaoba, Nagahahikari and Tachiwase) of Italian ryegrass (Lolium multiflorum Lam.) silage were precisely characterized by a combination of phenotypic tests, genotypic 16S ribosomal DNA sequencing and rapid PCR-based analyses, focusing on their useful phenotypes for silage preparation as inoculants. We successfully identified both at the species and subspecies levels: phenotypically novel Lactococcus lactis subsp. lactis, Lactobacillus brevis, Lactobacillus coryniformis subsp. torquens, Lactobacillus curvatus, Lactobacillus plantarum subsp. plantarum, Lactobacillus sakei subsp. carnosus, Leuconostoc mesenteroides subsp. dextranicum and Pediococcus parvulus. This is the first report to elucidate the presence of Lactobacillus coryniformis ssp. torquens and Leuconostoc mesenteroides subsp. dextranicum in Italian ryegrass silages. Physiological and biochemical tests revealed that phenotypic characteristics are different among the different strains of the same species and subspecies, and that the isolates show unique and diverse phenotypes related to fermentation factors, such as available carbohydrates, optimal growth pH and temperature. These results suggest that, for various well-preserved silage preparations, the isolates may be useful in producing novel inoculants corresponding to their optimally climatic and ecological niches. PMID:22339691

  18. Biopreservation of Brined Shrimp (Pandalus borealis) by Bacteriocins from Lactic Acid Bacteria

    PubMed Central

    Einarsson, H.; Lauzon, H. L.

    1995-01-01

    In brined shrimp (ca. 3% NaCl), the effects of three different lactic acid bacteria bacteriocins (crude [6.54 x 10(sup10) U of bacteriocin activity {BU}/g] and purified [8.13 x 10(sup23) BU/g] nisin Z, carnocin UI49 [2.32 x 10(sup4) BU/g], and crude bavaricin A [2.78 BU/g]) on bacterial growth and shelf life were compared with those of a benzoate-sorbate solution (0.1% each [wt/wt]) and a control with no preservatives. The shelf life of shrimp subjected to the control treatment was found to be 10 days. Carnocin UI49 did not extend the shelf life, while crude bavaricin A (a cell-free supernatant of Lactobacillus bavaricus MI 401) resulted in a shelf life of 16 days, as opposed to 31 days with nisin Z for both its crude and purified forms. The benzoate-sorbate solution preserved the brined shrimp for the whole storage period (59 days). In the control, carnocin UI49, and crude bavaricin A treatments, a gram-positive flora dominated towards the end of the storage period while in the nisin Z treatment a gram-negative flora was more pronounced. PMID:16534936

  19. In Vitro Properties of Potential Probiotic Indigenous Lactic Acid Bacteria Originating from Traditional Pickles.

    PubMed

    Tokatl?, Mehmet; Gülgör, Gök?en; Ba?der Elmac?, Simel; Arslankoz ??leyen, Nurdan; Özçelik, Filiz

    2015-01-01

    The suitable properties of potential probiotic lactic acid bacteria (LAB) strains (preselected among 153 strains on the basis of their potential technological properties) isolated from traditional Çubuk pickles were examined in vitro. For this purpose, these strains (21 Lactobacillus plantarum, 11 Pediococcus ethanolidurans, and 7 Lactobacillus brevis) were tested for the ability to survive at pH 2.5, resistance to bile salts, viability in the presence of pepsin-pancreatin, ability to deconjugate bile salts, cholesterol assimilation, and surface hydrophobicity properties. Most of the properties tested could be assumed to be strain-dependent. However, L. plantarum and L. brevis species were found to possess desirable probiotic properties to a greater extent compared to P. ethanolidurans. In contrast to P. ethanolidurans strains, the tested L. plantarum and L. brevis strains exhibited bile salt tolerance, albeit to different extent. All tested strains showed less resistance to intestinal conditions than gastric juice environment. Based on the survival under gastrointestinal conditions, 22 of the 39 strains were selected for further characterization. The eight strains having the highest cholesterol assimilation and surface hydrophobicity ratios could be taken as promising probiotic candidates for further in vivo studies, because of the strongest variations found among the tested strains with regard to these properties. PMID:26101771

  20. Uracil as an index of lactic acid bacteria contamination of tomato products.

    PubMed

    Hidalgo, Alyssa; Pompei, Carlo; Galli, Antonietta; Cazzola, Sara

    2005-01-26

    The aim of this research was to evaluate the suitability of uracil as an hygienic quality index of tomato products. Whereas uridine was naturally present throughout tomato fruits' ripening, uracil appeared only after microbial contamination. In tomato pulp inoculated with nine different microbial strains, all five lactic acid bacteria (LAB) studied released relevant quantities of uracil (150-1040 mg/kg of dm), with a correlated partial or total decrease of uridine. Uracil production by yeasts and molds was very low or nonexistent; the starting uridine concentration (approximately 960 mg/kg of dm) remained constant or increased. Uracil thermostability was also verified. Twenty-six samples of tomato paste (30 degrees Brix) were collected from bag-in-drums produced in an industrial processing plant, some with evident swelling symptoms. All of the samples with high microbial count presented uracil. Uracil was also present in samples with microbial contamination under the detection limit and Howard mold count below legislation limits, implying the reprocessing, at least partial, of altered tomato product. The results indicate that uracil presence in tomato products is an index of LAB contamination that has occurred before heat treatment. PMID:15656671

  1. Antibiotic resistance in lactic acid bacteria isolated from some pharmaceutical and dairy products.

    PubMed

    Gad, Gamal Fadl M; Abdel-Hamid, Ahmed M; Farag, Zeinab Shawky H

    2014-01-01

    A total of 244 lactic acid bacteria (LAB) strains were isolated from 180 dairy and pharmaceutical products that were collected from different areas in Minia governorate, Egypt. LAB were identified phenotypically on basis of morphological, physiological and biochemical characteristics. Lactobacillus isolates were further confirmed using PCR-based assay. By combination of phenotypic with molecular identification Lactobacillus spp. were found to be the dominant genus (138, 76.7%) followed by Streptococcus spp. (65, 36.1%) and Lactococcus spp. (27, 15%). Some contaminant organisms such as (Staphylococcus spp., Escherichia coli, Salmonella spp., mould and yeast) were isolated from the collected dairy samples but pharmaceutical products were free of such contaminants. Susceptibility of LAB isolates to antibiotics representing all major classes was tested by agar dilution method. Generally, LAB were highly susceptible to Beta-lactams except penicillin. Lactobacilli were resistant to vancomycin, however lactococci and streptococci proved to be very susceptible. Most strains were susceptible to tetracycline and showed a wide range of streptomycin MICs. The MICs of erythromycin and clindamycin for most of the LAB were within the normal range of susceptibility. Sixteen Lactobacillus, 8 Lactococcus and 8 Streptococcus isolates including all tetracycline and/or erythromycin resistant strains were tested for the presence of tetracycline and/or erythromycin resistant genes [tet(M) and/or erm(B)]. PCR assays shows that some resistant strains harbor tet(M) and/or erm(B) resistance genes. PMID:24948910

  2. Cereal fungal infection, mycotoxins, and lactic acid bacteria mediated bioprotection: from crop farming to cereal products.

    PubMed

    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. PMID:24230476

  3. Diversity of bacteriocinogenic lactic acid bacteria isolated from Mediterranean fish viscera.

    PubMed

    Migaw, Sarra; Ghrairi, Taoufik; Belguesmia, Yanath; Choiset, Yvan; Berjeaud, Jean-Marc; Chobert, Jean-Marc; Hani, Khaled; Haertlé, Thomas

    2014-04-01

    Nine lactic acid bacteria strains showing bacteriocin-like activity were isolated from various fresh fish viscera. The following species were identified based on 16S rDNA sequences: Enterococcus durans (7 isolates), Lactococcus lactis (1) and Enterococcus faecium (1). These strains were active against Listeria innocua and other LAB. Random amplified polymorphic DNA analyses showed four major patterns for the E. durans species. PCR analyses revealed a nisin gene in the genome of the Lc. lactis strain. Genes coding enterocins A, B and P were found in the genome of the E. faecium isolate. Enterocins A and B genes were also present in the genome of E. durans GM19. Hence, this is the first report describing E. durans strains producing enterocins A and B. Electrospray ionization mass spectrometry revealed that the purified bacteriocin produced by the E. durans GMT18 strain had an exact molecular mass of 6,316.89 Da. This bacteriocin was designated as durancin GMT18. Edman sequencing failed to proceed; suggesting that durancin GTM18 may contain terminal lanthionine residues. Overall, the results obtained revealed the presence of a variety of enterococci in Mediterranean fish viscera, as evidenced by their genetic profiles and abilities to produce different bacteriocins. These strains could be useful for food biopreservation or as probiotics. PMID:24189971

  4. Comparison of homo- and heterofermentative lactic acid bacteria for implementation of fermented wheat bran in bread.

    PubMed

    Prückler, Michael; Lorenz, Cindy; Endo, Akihito; Kraler, Manuel; Dürrschmid, Klaus; Hendriks, Karel; Soares da Silva, Francisco; Auterith, Eric; Kneifel, Wolfgang; Michlmayr, Herbert

    2015-08-01

    Despite its potential health benefits, the integration of wheat bran into the food sector is difficult due to several adverse technological and sensory properties such as bitterness and grittiness. Sourdough fermentation is a promising strategy to improve the sensory quality of bran without inducing severe changes to the bran matrix. Therefore, identification of species/strains with potential for industrial sourdough fermentations is important. We compared the effects of different representatives of species of lactic acid bacteria (LAB) on wheat bran. Lactobacillus plantarum, Lactobacillus pentosus, Lactobacillus brevis, Lactobacillus sanfranciscensis and Fructobacillus fructosus produced highly individual fermentation patterns as judged from carbohydrate consumption and organic acid production. Interestingly, fructose was released during all bran fermentations and possibly influenced the fermentation profiles of obligately heterofermentative species to varying degrees. Except for the reduction of ferulic acid by L. plantarum and L. pentosus, analyses of phenolic compounds and alkylresorcinols suggested that only minor changes thereof were induced by the LAB metabolism. Sensory analysis of breads baked with fermented bran did not reveal significant differences regarding perceived bitterness and aftertaste. We conclude that in addition to more traditionally used sourdough species such as L. sanfranciscensis and L. brevis, also facultatively heterofermentative species such as L. plantarum and L. pentosus possess potential for industrial wheat bran fermentations and should be considered in further investigations. PMID:25846933

  5. Fresh-cut pineapple as a new carrier of probiotic lactic acid bacteria.

    PubMed

    Russo, Pasquale; de Chiara, Maria Lucia Valeria; Vernile, Anna; Amodio, Maria Luisa; Arena, Mattia Pia; Capozzi, Vittorio; Massa, Salvatore; Spano, Giuseppe

    2014-01-01

    Due to the increasing interest for healthy foods, the feasibility of using fresh-cut fruits to vehicle probiotic microorganisms is arising scientific interest. With this aim, the survival of probiotic lactic acid bacteria, belonging to Lactobacillus plantarum and Lactobacillus fermentum species, was monitored on artificially inoculated pineapple pieces throughout storage. The main nutritional, physicochemical, and sensorial parameters of minimally processed pineapples were monitored. Finally, probiotic Lactobacillus were further investigated for their antagonistic effect against Listeria monocytogenes and Escherichia coli O157:H7 on pineapple plugs. Our results show that at eight days of storage, the concentration of L. plantarum and L. fermentum on pineapples pieces ranged between 7.3 and 6.3 log cfu g(-1), respectively, without affecting the final quality of the fresh-cut pineapple. The antagonistic assays indicated that L. plantarum was able to inhibit the growth of both pathogens, while L. fermentum was effective only against L. monocytogenes. This study suggests that both L. plantarum and L. fermentum could be successfully applied during processing of fresh-cut pineapples, contributing at the same time to inducing a protective effect against relevant foodborne pathogens. PMID:25093163

  6. Screening of lactic acid bacteria from vacuum packaged beef for antimicrobial activity

    PubMed Central

    Oliveira, Roseane B. P.; de L. Oliveira, Afonso; Glória, M. Beatriz A.

    2008-01-01

    The objective of this study was to isolate lactic acid bacteria (LAB) from vacuum packaged beef and to investigate their antagonist activity. LAB mean counts of 5.19 log cfu/cm2 were obtained from five samples of vacuum packaged beef. Two hundred isolates were selected and screened for the inhibitory effect on five ATCC reference Lactobacillus strains. Thirty six isolates showed activity in the agar spot test against at least two of the indicator strains. However, only six cell free supernatants (CFS) from these isolates exhibited activity against the indicator strains using the well-diffusion test and conditions that eliminated the effects of organic acids and hydrogen peroxide. L. acidophilus was the most sensitive indicator tested, whereas L. plantarum and L. fermentum were the most resistant ones. Identification by MIDI system indicated that these LAB isolates were Lactococcus lactis subsp. cremoris, Pediococcus acidilactici, Lactobacillus delbrueckii subsp. bulgaricus and Lactobacillus casei GC subgroup A. The antagonistic factors produced by most of these LAB against L. acidophilus were resistant to heat treatment (100°C for 10 min) and stable over a wide pH range (4.0 to 9.0). These data suggest that these isolates could be used as promising hurdles aiming increased safety and extended shelf life of meat products. PMID:24031232

  7. Diversity of lactic acid bacteria associated with fresh coffee cherries in Taiwan.

    PubMed

    Leong, Kun-hon; Chen, Yi-sheng; Pan, Shwu-fen; Chen, Jen-jye; Wu, Hui-chung; Chang, Yu-chung; Yanagida, Fujitoshi

    2014-04-01

    A total of 102 lactic acid bacteria (LAB) were isolated from three different coffee farms in Taiwan. These isolates were classified and identified by the restriction fragment length polymorphism analysis and sequencing of 16S ribosomal DNA. Heterofermentative Leuconostoc, and Weissella species were the most common LAB found in two farms located at an approximate altitude of 800 m. Lactococcus lactis subsp. lactis was the most common LAB found in the remaining farm was located at an approximate altitude of 1,200 m. It is therefore suggested that the altitude and climate may affect the distribution of LAB. On the basis of phylogenetic analysis, two strains included in the genera Enterococcus were considered as two potential novel species or subspecies. In addition, a total of 34 isolates showed the antifungal activity against Aspergillus flavus. Moreover, seven Lactococcus lactis subsp. lactis strains and one Enterococcus faecalis strain were found to have bacteriocin-like inhibitory substance-producing capability. These results suggest that various LAB are associated with fresh coffee cherries in Taiwan. Some of the isolates found in this study showed potential as antifungal agents. PMID:24292770

  8. Enzymatic activities of lactic acid bacteria isolated from Cornetto di Matera sourdoughs.

    PubMed

    Zotta, Teresa; Ricciardi, Annamaria; Parente, Eugenio

    2007-04-10

    Forty-one strains of lactic acid bacteria (LAB) isolated from Cornetto di Matera sourdoughs were screened for their enzymatic activities, to elucidate their possible roles during the fermentation process. Urease, peptidase, phytase, phosphatase and beta-glucosidase activities were measured spectrophotometrically using synthetic substrates. Proteolytic activities were examined in model doughs, using neutral and acidified sterile doughs as controls. All strains had low urease, glutamyl aminopeptidase and iminopeptidase activities, whereas differences within species were observed for the other enzymatic activities. Leuconostoc mesenteroides and Lactobacillus curvatus strains generally showed high aminopeptidase, X-prolyl dipeptidyl aminopeptidase, beta-glucosidase and phytase activities, while the enzymatic activities of Lactobacillus plantarum, Lactobacillus pentosus and Weissella cibaria varied between strains. In order to classify the strains on the basis of similar enzymatic profiles, a hierarchical cluster analysis was carried out. Several strains of L. plantarum, L. curvatus and Leuc. mesenteroides showed an interesting combination of proteolytic, peptidase, beta-glucosidase and phytase activities, suggesting their possible usefulness as a mixed starter culture in bread-making processes. PMID:17174429

  9. Interaction of Aeromonas strains with lactic acid bacteria via Caco-2 cells.

    PubMed

    Hatje, E; Neuman, C; Katouli, M

    2014-01-01

    The genus Aeromonas includes some species that have now been identified as human pathogens of significant medical importance. We investigated the ability of 13 selected Aeromonas strains belonging to nine species isolated from clinical cases (n = 5), environmental waters (n = 5), and fish (n = 3) to adhere to and translocate Caco-2 cells in the absence and presence of two lactic acid bacteria (LAB), i.e., Lactobacillus acidophilus and Bifidobacterium breve. Aeromonas isolates were also assessed for their cytotoxicity, the presence of virulence genes, and hemolysin production. Among the clinical isolates, one strain of Aeromonas veronii biovar veronii and two strains of Aeromonas hydrophila carried cytotoxin (act), heat-labile toxin (alt), hemolysin (hlyA), and aerolysin (aerA) genes, were cytotoxic to Vero cells, produced hemolysin, and showed higher adherence to Caco-2 cells. In contrast, this was seen in only one environmental strain, a strain of A. veronii biovar sobria. When Aeromonas strains were coinoculated with LAB onto Caco-2 cells, their level of adhesion was reduced. However, their rate of translocation in the presence of LAB increased and was significantly (P < 0.05) higher among fish strains. We suggest that either the interaction between Aeromonas and LAB strains could have a detrimental effect on the Caco-2 cells, allowing the Aeromonas to translocate more readily, or the presence of the LAB stimulated the Aeromonas strains to produce more toxins and/or increase their translocation rate. PMID:24242240

  10. Antibiotic resistance in lactic acid bacteria isolated from some pharmaceutical and dairy products

    PubMed Central

    Gad, Gamal Fadl M.; Abdel-Hamid, Ahmed M.; Farag, Zeinab Shawky H.

    2014-01-01

    A total of 244 lactic acid bacteria (LAB) strains were isolated from 180 dairy and pharmaceutical products that were collected from different areas in Minia governorate, Egypt. LAB were identified phenotypically on basis of morphological, physiological and biochemical characteristics. Lactobacillus isolates were further confirmed using PCR-based assay. By combination of phenotypic with molecular identification Lactobacillus spp. were found to be the dominant genus (138, 76.7%) followed by Streptococcus spp. (65, 36.1%) and Lactococcus spp. (27, 15%). Some contaminant organisms such as (Staphylococcus spp., Escherichia coli, Salmonella spp., mould and yeast) were isolated from the collected dairy samples but pharmaceutical products were free of such contaminants. Susceptibility of LAB isolates to antibiotics representing all major classes was tested by agar dilution method. Generally, LAB were highly susceptible to Beta-lactams except penicillin. Lactobacilli were resistant to vancomycin, however lactococci and streptococci proved to be very susceptible. Most strains were susceptible to tetracycline and showed a wide range of streptomycin MICs. The MICs of erythromycin and clindamycin for most of the LAB were within the normal range of susceptibility. Sixteen Lactobacillus, 8 Lactococcus and 8 Streptococcus isolates including all tetracycline and/or erythromycin resistant strains were tested for the presence of tetracycline and/or erythromycin resistant genes [tet(M) and/or erm(B)]. PCR assays shows that some resistant strains harbor tet(M) and/or erm(B) resistance genes. PMID:24948910

  11. In Vitro Properties of Potential Probiotic Indigenous Lactic Acid Bacteria Originating from Traditional Pickles

    PubMed Central

    Tokatl?, Mehmet; Gülgör, Gök?en; Ba?der Elmac?, Simel; Arslankoz ??leyen, Nurdan; Özçelik, Filiz

    2015-01-01

    The suitable properties of potential probiotic lactic acid bacteria (LAB) strains (preselected among 153 strains on the basis of their potential technological properties) isolated from traditional Çubuk pickles were examined in vitro. For this purpose, these strains (21 Lactobacillus plantarum, 11 Pediococcus ethanolidurans, and 7 Lactobacillus brevis) were tested for the ability to survive at pH 2.5, resistance to bile salts, viability in the presence of pepsin-pancreatin, ability to deconjugate bile salts, cholesterol assimilation, and surface hydrophobicity properties. Most of the properties tested could be assumed to be strain-dependent. However, L. plantarum and L. brevis species were found to possess desirable probiotic properties to a greater extent compared to P. ethanolidurans. In contrast to P. ethanolidurans strains, the tested L. plantarum and L. brevis strains exhibited bile salt tolerance, albeit to different extent. All tested strains showed less resistance to intestinal conditions than gastric juice environment. Based on the survival under gastrointestinal conditions, 22 of the 39 strains were selected for further characterization. The eight strains having the highest cholesterol assimilation and surface hydrophobicity ratios could be taken as promising probiotic candidates for further in vivo studies, because of the strongest variations found among the tested strains with regard to these properties.

  12. Impact of an Aerobic Thermophilic Sequencing Batch Reactor on Antibiotic-Resistant Anaerobic Bacteria in Swine Waste

    Microsoft Academic Search

    Martin R. Chénier; Pierre Juteau

    2009-01-01

    The introduction of antibiotics to animal feed has contributed to the selection of antibiotic-resistant bacteria in concentrated\\u000a animal feeding operations. The aim of this work was to characterize the impact of an aerobic thermophilic biotreatment on\\u000a anaerobic antibiotic-resistant bacteria in swine waste. Despite 162- to 6,166-fold reduction in antibiotic-resistant populations\\u000a enumerated in the swine waste at 25°C and 37°C, resistant

  13. Heterologous protein display on the cell surface of lactic acid bacteria mediated by the s-layer protein

    PubMed Central

    2011-01-01

    Background Previous studies have revealed that the C-terminal region of the S-layer protein from Lactobacillus is responsible for the cell wall anchoring, which provide an approach for targeting heterologous proteins to the cell wall of lactic acid bacteria (LAB). In this study, we developed a new surface display system in lactic acid bacteria with the C-terminal region of S-layer protein SlpB of Lactobacillus crispatus K2-4-3 isolated from chicken intestine. Results Multiple sequence alignment revealed that the C-terminal region (LcsB) of Lb. crispatus K2-4-3 SlpB had a high similarity with the cell wall binding domains SA and CbsA of Lactobacillus acidophilus and Lb. crispatus. To evaluate the potential application as an anchoring protein, the green fluorescent protein (GFP) or beta-galactosidase (Gal) was fused to the N-terminus of the LcsB region, and the fused proteins were successfully produced in Escherichia coli, respectively. After mixing them with the non-genetically modified lactic acid bacteria cells, the fused GFP-LcsB and Gal-LcsB were functionally associated with the cell surface of various lactic acid bacteria tested. In addition, the binding capacity could be improved by SDS pretreatment. Moreover, both of the fused proteins could simultaneously bind to the surface of a single cell. Furthermore, when the fused DNA fragment of gfp:lcsB was inserted into the Lactococcus lactis expression vector pSec:Leiss:Nuc, the GFP could not be secreted into the medium under the control of the nisA promoter. Western blot, in-gel fluorescence assay, immunofluorescence microscopy and SDS sensitivity analysis confirmed that the GFP was successfully expressed onto the cell surface of L. lactis with the aid of the LcsB anchor. Conclusion The LcsB region can be used as a functional scaffold to target the heterologous proteins to the cell surfaces of lactic acid bacteria in vitro and in vivo, and has also the potential for biotechnological application. PMID:22035337

  14. Study of Lactic Acid Bacteria Community From Raw Milk of Iranian One Humped Camel and Evaluation of Their Probiotic Properties

    PubMed Central

    Davati, Nafiseh; Tabatabaee Yazdi, Farideh; Zibaee, Saeed; Shahidi, Fakhri; Edalatian, Mohammad Reza

    2015-01-01

    Background: Camel milk is amongst valuable food sources in Iran. On the other hand, due to the presence of probiotic bacteria and bacteriocin producers in camel milk, probiotic bacteria can be isolated and identified from this food product. Objectives: The objectives of the present research were the isolation and molecular identification of lactic acid bacteria from camel milk and evaluation of their probiotic properties. Materials and Methods: A total of ten samples of camel milk were collected from the Golestan province of Iran under aseptic conditions. Bacteria were isolated by culturing the samples on selective medium. Isolates were identified by amplification of the 16S rDNA and Internal Transcribed Spacer (ITS) region between the 16S and 23S rRNA genes by Polymerase Chain Reaction (PCR) and were then screened and grouped by the Amplified Ribosomal DNA Restriction Analysis (ARDRA) method. To evaluate probiotic properties, representative isolates of different ARDRA profiles were analyzed. The antimicrobial activity of Lactic Acid Bacteria (LAB) against Pediococcus pentosaceus, Escherichia coli and Bacillus cereus was examined by the agar diffusion assay. Acid and bile tolerance of isolates were evaluated. Results: A total of 64 isolates were analyzed based on biochemical tests and morphological characteristics. The most frequently isolated LAB was Enterococci. Weissella, Leuconostoc, Lactobacilli and Pediococci were less frequently found. Based on restriction analysis of the ITS, the isolates were grouped into nine different ARDRA patterns that were identified by ribosomal DNA sequencing as P. pentosaceus, Enterococcus faecium strain Y-2, E. faecium strain JZ1-1, E. faecium strain E6, E. durans, E. lactis, Leuconostoc mesenteroides, Lactobacillus casei and Weissella cibaria. The results showed that antimicrobial activity of the tested isolates was remarkable and P. pentosaceus showed the most antibacterial activity. In addition, E. durans, E. lactis, L. casei and P. pentosaceus were selected as probiotic bacteria. Conclusions: This study revealed the presence of bacteriocin-producing bacteria and probiotic bacteria in camel milk from the Golestan province of Iran. PMID:26060561

  15. Ammonium-oxidizing bacteria facilitate aerobic degradation of sulfanilic acid in activated sludge.

    PubMed

    Chen, Gang; Ginige, Maneesha P; Kaksonen, Anna H; Cheng, Ka Yu

    2014-01-01

    Sulfanilic acid (SA) is a toxic sulfonated aromatic amine commonly found in anaerobically treated azo dye contaminated effluents. Aerobic acclimatization of SA-degrading mixed microbial culture could lead to co-enrichment of ammonium-oxidizing bacteria (AOB) because of the concomitant release of ammonium from SA oxidation. To what extent the co-enriched AOB would affect SA oxidation at various ammonium concentrations was unclear. Here, a series of batch kinetic experiments were conducted to evaluate the effect of AOB on aerobic SA degradation in an acclimatized activated sludge culture capable of oxidizing SA and ammonium simultaneously. To account for the effect of AOB on SA degradation, allylthiourea was used to inhibit AOB activity in the culture. The results indicated that specific SA degradation rate of the mixed culture was negatively correlated with the initial ammonium concentration (0-93 mM, R²= 0.99). The presence of AOB accelerated SA degradation by reducing the inhibitory effect of ammonium (? 10 mM). The Haldane substrate inhibition model was used to correlate substrate concentration (SA and ammonium) and oxygen uptake rate. This study revealed, for the first time, that AOB could facilitate SA degradation at high concentration of ammonium (? 10 mM) in an enriched activated sludge culture. PMID:25259503

  16. Analyses of spatial distributions of sulfate-reducing bacteria and their activity in aerobic wastewater biofilms

    SciTech Connect

    Okabe, Satoshi; Itoh, Tsukasa; Satoh, Hisashi; Watanabe, Yoshimasa

    1999-11-01

    The vertical distribution of sulfate-reducing bacteria (SRB) in aerobic wastewater biofilms grown on rotating disk reactors was investigated by fluorescent in situ hybridization (FISH) with 16S rRNA-targeted oligonucleotide probes. To correlate the vertical distribution of SRB populations with their activity, the microprofiles of O{sub 2}, H{sub 2}S, NO{sub 2}{minus}, NH{sub 2}{sup +}, and pH were measured with microelectrodes. In addition, a cross-evaluation of the FISH and microelectrode analyses was performed by comparing them with culture-based approaches and biogeochemical measurements. In situ hybridization revealed that a relatively high abundance of the probe SRB385-stained cells were evenly distributed throughout the biofilm, even in the toxic surface. The probe SRB660-stained Desulfobulbus spp. were found to be numerically important members of SRB populations. The result of microelectrode measurements showed that a high sulfate-reducing activity was found in a narrow anaerobic zone located about 150 to 300 {micro}m below the biofilm surface and above which an intensive sulfide oxidation zone was found. The biogeochemical measurements showed that elemental sulfur (S{degree}) was an important intermediate of the sulfide reoxidation in such thin wastewater biofilms, which accounted for about 75% of the total S pool in the biofilm. The contribution of an internal Fe-sulfur cycle to the overall sulfur cycle in aerobic wastewater biofilms was insignificant (less than 1%) due to the relatively high sulfate reduction rate.

  17. Culturable aerobic and facultative bacteria from the gut of the polyphagic dung beetle Thorectes lusitanicus.

    PubMed

    Hernández, Noemi; Escudero, José A; San Millán, Álvaro; González-Zorn, Bruno; Lobo, Jorge M; Verdú, José R; Suárez, Mónica

    2015-04-01

    Unlike other dung beetles, the Iberian geotrupid, Thorectes lusitanicus, exhibits polyphagous behavior; for example, it is able to eat acorns, fungi, fruits, and carrion in addition to the dung of different mammals. This adaptation to digest a wider diet has physiological and developmental advantages and requires key changes in the composition and diversity of the beetle's gut microbiota. In this study, we isolated aerobic, facultative anaerobic, and aerotolerant microbiota amenable to grow in culture from the gut contents of T. lusitanicus and resolved isolate identity to the species level by sequencing 16S rRNA gene fragments. Using BLAST similarity searches and maximum likelihood phylogenetic analyses, we were able to reveal that the analyzed fraction (culturable, aerobic, facultative anaerobic, and aerotolerant) of beetle gut microbiota is dominated by the phyla Proteobacteria, Firmicutes, and Actinobacteria. Among Proteobacteria, members of the order Enterobacteriales (Gammaproteobacteria) were the most abundant. The main functions associated with the bacteria found in the gut of T. lusitanicus would likely include nitrogen fixation, denitrification, detoxification, and diverse defensive roles against pathogens. PMID:24339348

  18. Comparison between Rinse and Crush-and-Rub Sampling for Aerobic Bacteria Recovery from Hatching Eggs after Sanitization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study compared surface and deep eggshell aerobic bacteria recovered by rinse and crush-and-rub sampling methods for commercial hatching eggs after treatments with sanitizers. Eggs were arranged into 5 treatments consisting of three sanitizers, Water, and No-treatment. Sanitizers were Hydrogen...

  19. Distribution of bacteriochlorophyll a among aerobic and acidophilic bacteria and light-enhanced CO 2-incorporation in Acidiphilium rubrum

    Microsoft Academic Search

    Noriaki Kishimoto; Fumihito Fukaya; Kenji Inagaki; Tsuyoshi Sugio; Hidehiko Tanaka; Tatsuo Tano

    1995-01-01

    Four Acidiphilium species among aerobic and acidophilic bacteria, Acidiphilium angustum, Acidiphilium cryptum, Acidiphilium organovorum, and Acidiphilium rubrum, produced the bacteriochlorophyll a (0.005 ~ 0.76 nmol mg?1 dried cells), whereas Acidiphilium aminolytica, Acidiphilium facilis, Acidomonas methanolica, Acidobacterium capsulatum. Thiobacillus acidophilus, Thiobacillus ferrooxidans, and Thiohacillus thiooxidans produced no phototrophic pigments. Bacteriochlorophyll a was purified from A. rubrum to a single spot on

  20. Comparison between rinse and crush-and-rub sampling for aerobic bacteria recovery from broiler hatching eggs after sanitization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study compared surface and deep eggshell aerobic bacteria recovered by rinse and crush-and-rub sampling methods for commercial hatching eggs after treatment with sanitizers. Eggs were arranged into 5 treatments consisting of No-treatment, Water, and three sanitizers. Sanitizers were Hydrogen ...

  1. Suppression of growth of putrefactive and food poisoning bacteria by lactic acid fermentation of kitchen waste

    Microsoft Academic Search

    Q Wang; K Yamabe; J Narita; M Morishita; Y Ohsumi; K Kusano; Y Shirai; H. I Ogawa

    2001-01-01

    In order to produce lactic acid, from kitchen waste, which is a raw material for biodegradable plastic production, it is necessary to store waste for some days in the system of kitchen waste collection and transportation through disposers and pipes. The changes of counts of viable cells in kitchen waste during storage were observed. In spite of seasonal variations, lactic

  2. Nitrogen-Fixing (Acetylene Redution) Activity and Population of Aerobic Heterotrophic Nitrogen-Fixing Bacteria Associated with Wetland Rice

    PubMed Central

    Watanabe, Iwao; Barraquio, Wilfredo L.; De Guzman, Marcelino R.; Cabrera, Delfin A.

    1979-01-01

    Nitrogen-fixing activity associated with different wetland rice varieties was measured at various growth stages by an in situ acetylene reduction method after the activities of blue-green algae (cyanobacteria) in the flood water and on the lower portion of the rice stem were eliminated. Nitrogen-fixing activities associated with rice varieties differed with plant growth stages. The activities increased with plant age, and the maximum was about at heading stage. The nitrogen fixed during the whole cropping period was estimated at 5.9 kg of N per ha for variety IR26 (7 days) and 4.8 kg of N per ha for variety IR36 (95 days). The population of aerobic heterotrophic N2-fixing bacteria associated with rice roots and stems was determined by the most-probable-number method, using semisolid glucose-yeast extract and semisolid malate-yeast extract media. The addition of yeast extract to the glucose medium increased the number and activity of aerobic heterotrophic N2-fixing bacteria. The glucose-yeast extract medium gave higher counts of aerobic N2-fixing bacteria associated with rice roots than did the malate-yeast extract medium, on which Spirillum-like bacteria were usually observed. The lower portion of the rice stem was also inhabited by N2-fixing bacteria and was an active site of N2 fixation. PMID:16345379

  3. Aerobic and facultatively anaerobic bacteria associated with the gut of Canada geese (Branta canadensis) and whistling swans (Cygnus columbianus columbianus).

    PubMed

    Damaré, J M; Hussong, D; Weiner, R M; Colwell, R R

    1979-08-01

    Aerobic and facultatively anaerobic bacteria from the intestinal tracts of swans and geese were isolated and characterized as part of a larger study of the microbiological effects of migratory waterfowl on water quality. A total of 356 isolates were identified by using rapid identification methods and classified by using numerical taxonomy. A diverse population of bacteria was recovered from the waterfowl, and representative strains could be classified into 21 phena. The majority of the aerobic, heterotrophic bacteria found in the gut of the waterfowl were species of Enterobacteriaceae. Streptococcus. Lactobacillus, and Bacillus. Unfortunately, the birds that were examined did not harbor significant numbers of any waterfowl-specific bacterial species. Thus, it may not be possible to assess microbiological impact of migratory waterfowl by using and "indicator" species since avian fecal pollution could not be distinguished from animal and human fecal pollution. PMID:518085

  4. Aerobic and facultatively anaerobic bacteria associated with the gut of Canada geese (Branta canadensis) and whistling swans (Cygnus columbianus columbianus).

    PubMed Central

    Damaré, J M; Hussong, D; Weiner, R M; Colwell, R R

    1979-01-01

    Aerobic and facultatively anaerobic bacteria from the intestinal tracts of swans and geese were isolated and characterized as part of a larger study of the microbiological effects of migratory waterfowl on water quality. A total of 356 isolates were identified by using rapid identification methods and classified by using numerical taxonomy. A diverse population of bacteria was recovered from the waterfowl, and representative strains could be classified into 21 phena. The majority of the aerobic, heterotrophic bacteria found in the gut of the waterfowl were species of Enterobacteriaceae. Streptococcus. Lactobacillus, and Bacillus. Unfortunately, the birds that were examined did not harbor significant numbers of any waterfowl-specific bacterial species. Thus, it may not be possible to assess microbiological impact of migratory waterfowl by using and "indicator" species since avian fecal pollution could not be distinguished from animal and human fecal pollution. PMID:518085

  5. Biodiversity of lactic acid bacteria and yeasts in spontaneously-fermented buckwheat and teff sourdoughs.

    PubMed

    Moroni, Alice V; Arendt, Elke K; Dal Bello, Fabio

    2011-05-01

    In this study, four different laboratory scale gluten-free (GF) sourdoughs were developed from buckwheat or teff flours. The fermentations were initiated by the spontaneous biota of the flours and developed under two technological conditions (A and B). Sourdoughs were propagated by continuous back-slopping until the stability was reached. The composition of the stable biota occurring in each sourdough was assessed using both culture-dependent and -independent techniques. Overall, a broad spectrum of lactic acid bacteria (LAB) and yeasts species, belonging mainly to the genera Lactobacillus, Pediococcus, Leuconostoc, Kazachstania and Candida, were identified in the stable sourdoughs. Buckwheat and teff sourdoughs were dominated mainly by obligate or facultative heterofermentative LAB, which are commonly associated with traditional wheat or rye sourdoughs. However, the spontaneous fermentation of the GF flours resulted also in the selection of species which are not consider endemic to traditional sourdoughs, i.e. Pediococcus pentosaceus, Leuconostoc holzapfelii, Lactobacillus gallinarum, Lactobacillus vaginalis, Lactobacillus sakei, Lactobacillus graminis and Weissella cibaria. In general, the composition of the stable biota was strongly affected by the fermentation conditions, whilst Lactobacillus plantarum dominated in all buckwheat sourdoughs. Lactobacillus pontis is described for the first time as dominant species in teff sourdough. Among yeasts, Saccharomyces cerevisiae and Candida glabrata dominated teff sourdoughs, whereas the solely Kazachstania barnetti was isolated in buckwheat sourdough developed under condition A. This study allowed the identification and isolation of LAB and yeasts species which are highly competitive during fermentation of buckwheat or teff flours. Representatives of these species can be selected as starters for the production of sourdough destined to GF bread production. PMID:21356457

  6. Codominance of Lactobacillus plantarum and obligate heterofermentative lactic acid bacteria during sourdough fermentation.

    PubMed

    Ventimiglia, Giusi; Alfonzo, Antonio; Galluzzo, Paola; Corona, Onofrio; Francesca, Nicola; Caracappa, Santo; Moschetti, Giancarlo; Settanni, Luca

    2015-10-01

    Fifteen sourdoughs produced in western Sicily (southern Italy) were analysed by classical methods for their chemico-physical characteristics and the levels of lactic acid bacteria (LAB). pH and total titratable acidity (TTA) were mostly in the range commonly reported for similar products produced in Italy, but the fermentation quotient (FQ) of the majority of samples was above 4.0, due to the low concentration of acetic acid estimated by high performance liquid chromatography (HPLC). Specific counts of LAB showed levels higher than 10(8) CFU g(-1) for many samples. The colonies representing various morphologies were isolated and, after the differentiation based on phenotypic characteristics, divided into 10 groups. The most numerous group was composed of facultative heterofermentative isolates, indicating a relevance of this bacterial group during fermentation. The genetic analysis by randomly amplified polymorphic DNA (RAPD)-PCR, 16S rRNA gene sequencing and species-specific PCRs identified 33 strains as Lactobacillus plantarum, Lactobacillus curvatus and Lactobacillus graminis. Due to the consistent presence of L. plantarum, it was concluded that this species codominates with obligate heterofermentative LAB in sourdough production in this geographical area. In order to evaluate the performances at the basis of their fitness, the 29 L. plantarum strains were investigated for several technological traits. Twelve cultures showed good acidifying abilities in vitro and L. plantarum PON100148 produced the highest concentrations of organic acids. Eleven strains were positive for extracellular protease activity. Bacteriocin-like inhibitory substances (BLIS) production and antifungal activity was scored positive for several strains, included L. plantarum PON100148 which was selected as starter for experimental sourdough production. The characteristics of the sourdoughs and the resulting breads indicated that the best productions were obtained in presence of L. plantarum PON100148. PMID:26187828

  7. Core Fluxome and Metafluxome of Lactic Acid Bacteria under Simulated Cocoa Pulp Fermentation Conditions

    PubMed Central

    Adler, Philipp; Bolten, Christoph Josef; Dohnt, Katrin; Hansen, Carl Erik

    2013-01-01

    In the present work, simulated cocoa fermentation was investigated at the level of metabolic pathway fluxes (fluxome) of lactic acid bacteria (LAB), which are typically found in the microbial consortium known to convert nutrients from the cocoa pulp into organic acids. A comprehensive 13C labeling approach allowed to quantify carbon fluxes during simulated cocoa fermentation by (i) parallel 13C studies with [13C6]glucose, [1,2-13C2]glucose, and [13C6]fructose, respectively, (ii) gas chromatography-mass spectrometry (GC/MS) analysis of secreted acetate and lactate, (iii) stoichiometric profiling, and (iv) isotopomer modeling for flux calculation. The study of several strains of L. fermentum and L. plantarum revealed major differences in their fluxes. The L. fermentum strains channeled only a small amount (4 to 6%) of fructose into central metabolism, i.e., the phosphoketolase pathway, whereas only L. fermentum NCC 575 used fructose to form mannitol. In contrast, L. plantarum strains exhibited a high glycolytic flux. All strains differed in acetate flux, which originated from fractions of citrate (25 to 80%) and corresponding amounts of glucose and fructose. Subsequent, metafluxome studies with consortia of different L. fermentum and L. plantarum strains indicated a dominant (96%) contribution of L. fermentum NCC 575 to the overall flux in the microbial community, a scenario that was not observed for the other strains. This highlights the idea that individual LAB strains vary in their metabolic contribution to the overall fermentation process and opens up new routes toward streamlined starter cultures. L. fermentum NCC 575 might be one candidate due to its superior performance in flux activity. PMID:23851099

  8. Molecular identification and quantification of lactic acid bacteria in traditional fermented dairy foods of Russia.

    PubMed

    Yu, J; Wang, H M; Zha, M S; Qing, Y T; Bai, N; Ren, Y; Xi, X X; Liu, W J; Menghe, B L G; Zhang, H P

    2015-08-01

    Russian traditional fermented dairy foods have been consumed for thousands of years. However, little research has focused on exploiting lactic acid bacteria (LAB) resources and analyzing the LAB composition of Russian traditional fermented dairy foods. In the present study, we cultured LAB isolated from fermented mare and cow milks, sour cream, and cheese collected from Kalmykiya, Buryats, and Tuva regions of Russia. Seven lactobacillus species and the Bifidobacterium genus were quantified by quantitative PCR. The LAB counts in these samples ranged from 3.18 to 9.77 log cfu/mL (or per gram). In total, 599 LAB strains were obtained from these samples using de Man, Rogosa, and Sharpe agar and M17 agar. The identified LAB belonged to 7 genera and 30 species by 16S rRNA and murE gene sequencing and multiplex PCR assay. The predominant LAB isolates were Lactobacillus helveticus (176 strains) and Lactobacillus plantarum (63 strains), which represented 39.9% of all isolates. The quantitative PCR results revealed that counts of 7 lactobacilli species and Bifidobacterium spp. of 30 fermented cow milk samples ranged from 1.19±0.34 (Lactobacillus helveticus in Tuva) to 8.09±0.71 (Lactobacillus acidophilus in Kalmykiya) log cfu/mL of fermented cow milk (mean ± standard error). The numbers of Bifidobacterium spp., Lb. plantarum, Lb. helveticus, and Lb. acidophilus revealed no significant difference between the 3 regions; nevertheless, Lactobacillus paracasei, Lactobacillus fermentum, Lactobacillus sakei, and Lactobacillus delbrueckii ssp. bulgaricus exhibited different degrees of variation across 3 regions. The results demonstrate that traditional fermented dairy products from different regions of Russia have complex compositions of LAB species. The diversity of LAB might be related to the type of fermented dairy product, geographical origin, and manufacturing process. PMID:26004836

  9. Diversity in growth and protein degradation by dairy relevant lactic acid bacteria species in reconstituted whey.

    PubMed

    Pescuma, Micaela; Hébert, Elvira M; Bru, Elena; Font de Valdez, Graciela; Mozzi, Fernanda

    2012-05-01

    The high nutritional value of whey makes it an interesting substrate for the development of fermented foods. The aim of this work was to evaluate the growth and proteolytic activity of sixty-four strains of lactic acid bacteria in whey to further formulate a starter culture for the development of fermented whey-based beverages. Fermentations were performed at 37 °C for 24 h in 10 and 16% (w/v) reconstituted whey powder. Cultivable populations, pH, and proteolytic activity (o-phthaldialdehyde test) were determined at 6 and 24 h incubation. Hydrolysis of whey proteins was analysed by Tricine SDS-PAGE. A principal component analysis (PCA) was applied to evaluate the behaviour of strains. Forty-six percent of the strains grew between 1 and 2 ?log CFU/ml while 19% grew less than 0·9 ?log CFU/ml in both reconstituted whey solutions. Regarding the proteolytic activity, most of the lactobacilli released amino acids and small peptides during the first 6 h incubation while streptococci consumed the amino acids initially present in whey to sustain growth. Whey proteins were degraded by the studied strains although to different extents. Special attention was paid to the main allergenic whey protein, ?-lactoglobulin, which was degraded the most by Lactobacillus acidophilus CRL 636 and Lb. delbrueckii subsp. bulgaricus CRL 656. The strain variability observed and the PCA applied in this study allowed selecting appropriate strains able to improve the nutritional characteristics (through amino group release and protein degradation) and storage (decrease in pH) of whey. PMID:22559062

  10. Regulation of the Activity of Lactate Dehydrogenases from Four Lactic Acid Bacteria*

    PubMed Central

    Feldman-Salit, Anna; Hering, Silvio; Messiha, Hanan L.; Veith, Nadine; Cojocaru, Vlad; Sieg, Antje; Westerhoff, Hans V.; Kreikemeyer, Bernd; Wade, Rebecca C.; Fiedler, Tomas

    2013-01-01

    Despite high similarity in sequence and catalytic properties, the l-lactate dehydrogenases (LDHs) in lactic acid bacteria (LAB) display differences in their regulation that may arise from their adaptation to different habitats. We combined experimental and computational approaches to investigate the effects of fructose 1,6-bisphosphate (FBP), phosphate (Pi), and ionic strength (NaCl concentration) on six LDHs from four LABs studied at pH 6 and pH 7. We found that 1) the extent of activation by FBP (Kact) differs. Lactobacillus plantarum LDH is not regulated by FBP, but the other LDHs are activated with increasing sensitivity in the following order: Enterococcus faecalis LDH2 ? Lactococcus lactis LDH2 < E. faecalis LDH1 < L. lactis LDH1 ? Streptococcus pyogenes LDH. This trend reflects the electrostatic properties in the allosteric binding site of the LDH enzymes. 2) For L. plantarum, S. pyogenes, and E. faecalis, the effects of Pi are distinguishable from the effect of changing ionic strength by adding NaCl. 3) Addition of Pi inhibits E. faecalis LDH2, whereas in the absence of FBP, Pi is an activator of S. pyogenes LDH, E. faecalis LDH1, and L. lactis LDH1 and LDH2 at pH 6. These effects can be interpreted by considering the computed binding affinities of Pi to the catalytic and allosteric binding sites of the enzymes modeled in protonation states corresponding to pH 6 and pH 7. Overall, the results show a subtle interplay among the effects of Pi, FBP, and pH that results in different regulatory effects on the LDHs of different LABs. PMID:23720742

  11. Growth and Arginine Metabolism of the Wine Lactic Acid Bacteria Lactobacillus buchneri and Oenococcus oeni at Different pH Values and Arginine Concentrations

    Microsoft Academic Search

    RAMON MIRA DE ORDUNA; MARK L. PATCHETT; SHAO-QUAN LIU; GORDON J. PILONE

    2001-01-01

    During malolactic fermentation (MLF) in grape must and wine, heterofermentative lactic acid bacteria may degrade arginine, leading to the formation of ammonia and citrulline, among other substances. This is of concern because ammonia increases the pH and thus the risk of growth by spoilage bacteria, and citrulline is a precursor to the formation of carcinogenic ethyl carbamate (EC). Arginine metabolism

  12. Cultivable microbiota of Lithobates catesbeianus and advances in the selection of lactic acid bacteria as biological control agents in raniculture.

    PubMed

    Mendoza, Gabriela Montel; Pasteris, Sergio E; Ale, Cesar E; Otero, María C; Bühler, Marta I; Nader-Macías, María E Fátima

    2012-12-01

    The cultivable microbiota of skin and cloaca of captive Lithobates catesbeianus includes microorganisms generally accepted as beneficial and potentially pathogenic bacteria. In order to select a group of potentially probiotic bacteria, 136 isolates were evaluated for their surface properties and production of antagonistic metabolites. Then, 11 lactic acid bacteria (LAB) strains were selected and identified as Lactobacillus plantarum, Lb. brevis, Pediococcus pentosaceus, Lactococcus lactis, L. garvieae and Enterococcus gallinarum. Studies of compatibility indicate that all the strains could be included in a multi-strain probiotic, with the exception of Ent. gallinarum CRL 1826 which inhibited LAB species through a bacteriocin-like metabolite. These results contribute to the design of a probiotic product to improve the sanitary status of bullfrogs in intensive culture systems, to avoid the use of antibiotics and thus to reduce production costs. It could also be an alternative to prevent infectious diseases during the ex situ breeding of amphibian species under threat of extinction. PMID:22695175

  13. The screening of hydrogen peroxide-producing lactic acid bacteria and their application to inactivating psychrotrophic food-borne pathogens.

    PubMed

    Ito, Ayano; Sato, Yuki; Kudo, Syoko; Sato, Susumu; Nakajima, Hajime; Toba, Takahiro

    2003-09-01

    Lactic acid bacteria were isolated from various food samples and evaluated for hydrogen peroxide (H2O2) production. Cells suspended in 0.5% (wt/vol) glucose plus 0.5% (wt/vol) lactate (pH 7.0) were incubated for 5 h at 37 degrees C under aeration. Among 193 strains, 27 strains accumulated 201-300 ppm H2O2, and 4 strains accumulated more than 301 ppm H2O2 in the cell suspensions. Among the 9 high-level H2O2-producing strains, 8 strains were identified as Lactococcus lactis subsp. lactis. The cell-free filtrate from Lc. lactis subsp. lactis AI 62, which contained approximately 350 ppm H2O2, was evaluated for antimicrobial activity against Enterococcus faecalis, Ent. faecium, enterotoxigenic Escherichia coli, Listeria ivanovii, Staphylococcus aureus, Yersinia enterocolitica, and Aeromonas hydrophila. After 1 h incubation at 30 degrees C in the cell-free filtrate, the initial viable cell counts of the target bacteria (5.53-6.00 log cfu/mL) were reduced by 0.12-5.00 log units, except in the case of enterococci. The sensitivity varied with the bacterial species and pH. The enterococci were resistant to the treatment. Our results show that H2O2 accumulated by lactic acid bacteria in a cell suspension is very effective in reducing the viable cell count of food-borne pathogens. PMID:14570275

  14. Hydroxycinnamic Acids Used as External Acceptors of Electrons: an Energetic Advantage for Strictly Heterofermentative Lactic Acid Bacteria

    PubMed Central

    Filannino, Pasquale; Gobbetti, Marco; De Angelis, Maria

    2014-01-01

    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. PMID:25261518

  15. Hydroxycinnamic acids used as external acceptors of electrons: an energetic advantage for strictly heterofermentative lactic acid bacteria.

    PubMed

    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. PMID:25261518

  16. Selective effect of the product type and the packaging conditions on the species of lactic acid bacteria dominating the spoilage microbial association of cooked meats at 4°C

    Microsoft Academic Search

    John Samelis; Athanasia Kakouri; John Rementzis

    2000-01-01

    The product type was shown to strongly affect the growth rate and the composition of the spoilage lactic flora during refrigerated (4°C) storage of cooked, cured meats, sharing their processing plant environment, day of production and film packaging conditions. Growth of lactic acid bacteria (LAB) under vacuum was more prolific on the product in the order: ham>turkey breast fillet>smoked pork

  17. Space agriculture for habitation on Mars with hyper-thermophilic aerobic composting bacteria

    NASA Astrophysics Data System (ADS)

    Space Agriculture Task Force; Ishikawa, Y.; Tomita-Yokotani, K.; Hashimoto, H.; Kitaya, Y.; Yamashita, M.; Nagatomo, M.; Oshima, T.; Wada, H.

    Manned Mars exploration, especially for extended periods of time, will require recycle of materials to support human life. Here, a conceptual design is developed for a Martian agricultural system driven by biologically regenerative functions. One of the core biotechnologies function is the use of hyper-thermophilic aerobic composting bacterial ecology. These thermophilic bacteria can play an important role in increasing the effectiveness of the processing of human metabolic waste and inedible biomass and of converting them to fertilizer for the cultivation of plants. This microbial technology has been already well established for the purpose of processing sewage and waste materials for small local communities in Japan. One of the characteristics of the technology is that the metabolic heat release that occurs during bacterial fermentation raises the processing temperature sufficiently high at 80 100 °C to support hyper-thermophilic bacteria. Such a hyper-thermophilic system is found to have great capability of decomposing wastes including even their normally recalcitrant components, in a reasonably short period of time and of providing a better quality of fertilizer as an end-product. High quality compost has been shown to be a key element in creating a healthy regenerative food production system. In ground-based studies, the soil microbial ecology after the addition of high quality compost was shown to improve plant growth and promote a healthy symbiosis of arbuscular mycorrhizal fungi. Another advantage of such high processing temperature is the ability to sterilize the pathogenic organisms through the fermentation process and thus to secure the hygienic safety of the system. Plant cultivation is one of the other major systems. It should fully utilize solar energy received on the Martian surface for supplying energy for photosynthesis. Subsurface water and atmospheric carbon dioxide mined on Mars should be also used in the plant cultivation system. Oxygen and food production for human thus rely on local Martian resources. A tree growing subsystem will also give an interesting feature to Martian agriculture. In addition to producing excess oxygen, trees’ rigid body will provide structural material, which can be used for habitat construction. The combination of hyper-thermophilic aerobic composting, plant cultivation, and tree growing with utilizing in-situ natural local resources available on Mars can provide important elements which can enable space agriculture on Mars.

  18. Prevalent lactic acid bacteria in cider cellars and efficiency of Oenococcus oeni strains.

    PubMed

    Sánchez, Ainoa; Coton, Monika; Coton, Emmanuel; Herrero, Mónica; García, Luis A; Díaz, Mario

    2012-10-01

    Malolactic fermentation (MLF) is an important step in cider production in order to allowing for improvement of microbiological stability and organoleptic characteristics of cider. Induction of this fermentation by using starter cultures enables a better control over this bioprocess, but although it is a common practice in winemaking, starters specifically focussed for cider MLF are not yet commercially available. Proper starter cultures need to present the ability to degrade l-malic acid conferring pleasing sensory characteristics while avoiding toxicological risks. In this work, lactic acid bacteria (LAB) were first isolated from MLF industrial cider samples, obtained in a cellar in the main cider-producing region of Spain, Asturias. Isolates, identified by molecular tools, belonged to the Lactobacillus brevis and Oenococcus oeni species. After a phylogenetic analysis, representative strains of both identified species were evaluated in order to determine their fermentation capacity, showing O. oeni the best behaviour in this cider fermentation, as previously demonstrated for wine in the literature. Consequently, and with the aim to test the influence at strain level, selection of O. oeni isolates as starters for cider fermentation has been undergone. In order to check the influence of geography over biodiversity, O. oeni strains from six different industrial cellars representing the distinct producing areas in the region (located in a ratio of 30 km) were analyzed by using a specific RAPD method. In this way, isolates were typed in five distinct groups, mainly corresponding to each producing area. All strains isolated from the same cellar showed the same RAPD profile revealing the significance of geographical origin in the indigenous cider LAB. Molecular tools were applied to reject those isolates exhibiting presence of genes related to organoleptic spoilage (exopolysaccharides and acrolein production) or food safety (biogenic amine production), as key selection criteria. Representative strains of each of the five O. oeni RAPD groups were tested as pure cultures to evaluate their technological utility for cider production. Experimental data of malic acid degradation and cell concentration obtained were fitted to previously selected kinetic models aimed to optimization and prediction of bioprocess performance. Four strains revealed as suitable potential starter cultures for conducting MLF in cider production. PMID:22850371

  19. Phytic acid degrading lactic acid bacteria in tef-injera fermentation.

    PubMed

    Fischer, Maren M; Egli, Ines M; Aeberli, Isabelle; Hurrell, Richard F; Meile, Leo

    2014-11-01

    Ethiopian injera, a soft pancake, baked from fermented batter, is preferentially prepared from tef (Eragrostis tef) flour. The phytic acid (PA) content of tef is high and is only partly degraded during the fermentation step. PA chelates with iron and zinc in the human digestive tract and strongly inhibits their absorption. With the aim to formulate a starter culture that would substantially degrade PA during injera preparation, we assessed the potential of microorganisms isolated from Ethiopian household-tef fermentations to degrade PA. Lactic acid bacteria (LAB) were found to be among the dominating microorganisms. Seventy-six isolates from thirteen different tef fermentations were analyzed for phytase activity and thirteen different isolates of seven different species were detected to be positive in a phytase screening assay. In 20-mL model tef fermentations, out of these thirteen isolates, the use of Lactobacillus (L.) buchneri strain MF58 and Pediococcus pentosaceus strain MF35 resulted in lowest PA contents in the fermented tef of 41% and 42%, respectively of its initial content. In comparison 59% of PA remained when spontaneously fermented. Full scale tef fermentation (0.6L) and injera production using L. buchneri MF58 as culture additive decreased PA in cooked injera from 1.05 to 0.34±0.02 g/100 g, representing a degradation of 68% compared to 42% in injera from non-inoculated traditional fermentation. The visual appearance of the pancakes was similar. The final molar ratios of PA to iron of 4 and to zinc of 12 achieved with L. buchneri MF58 were decreased by ca. 50% compared to the traditional fermentation. In conclusion, selected LAB strains in tef fermentations can degrade PA, with L. buchneri MF58 displaying the highest PA degrading potential. The 68% PA degradation achieved by the application of L. buchneri MF58 would be expected to improve human zinc absorption from tef-injera, but further PA degradation is probably necessary if iron absorption has to be increased. PMID:25180667

  20. Enrichment of ACE inhibitory peptides in navy bean (Phaseolus vulgaris) using lactic acid bacteria.

    PubMed

    Rui, Xin; Wen, Delan; Li, Wei; Chen, Xiaohong; Jiang, Mei; Dong, Mingsheng

    2015-02-11

    The present study was conducted to explore a novel strategy to enhance angiotensin I-converting enzyme (ACE) inhibitory activities of navy bean by preparation of navy bean milk (NBM) which was then subjected to fermentation of four lactic acid bacteria (LAB) strains, namely, Lactobacillus bulgaricus, Lactobacillus helveticus MB2-1, Lactobacillus plantarum B1-6, and Lactobacillus plantarum 70810. With the exception of L. helveticus MB2-1, the other three selected strains had good growth performances in NBM with viable counts increased to log 8.30-8.39 cfu ml(-1) during 6 h of fermentation, and thus were selected for the following investigations. Protein contents of NBM significantly reduced when treated with L. bulgaricus and L. plantarum B1-6, and the electrophoresis patterns showed the preferable proteins for LAB strains to hydrolyze were ?- and ?-type phaseolins, whereas ?-type phaseolin was resistant to hydrolysis. RP-HPLC analysis demonstrated all fermented NBM had higher intensities of peaks with retention times between 2.5 and 3.5 min indicative of formation of small peptides. All fermented NBM showed higher ACE inhibitory activity compared to the unfermented ones, for which 2 h, 3 h, and 5 h were found to be the optimum fermentation periods for respectively L. plantarum 70810, L. plantarum B1-6 and L. bulgaricus, with IC50 values of 109 ± 5.1, 108 ± 1.1, and 101 ± 2.2 ?g protein ml(-1). The subsequent in vitro gastrointestinal simulation afforded all fermented extracts reduced IC50 values and the extracts fermented by L. plantarum B1-6 exerted the lowest IC50 value of 21 ± 2.1 ?g protein ml(-1). The research has broadened our knowledge bases on the effect of LAB fermentation on the degradation of navy bean proteins and the capacity to release ACE inhibitory peptides. The approach was promising to obtain probiotic products with potential to serve as functional ingredients targeting hypertension. PMID:25536445

  1. Probiotic potential of lactic acid bacteria present in home made curd in southern India

    PubMed Central

    Balamurugan, Ramadass; Chandragunasekaran, Aarthi Sophia; Chellappan, Gowri; Rajaram, Krithika; Ramamoorthi, Gayathri; Ramakrishna, Balakrishnan S.

    2014-01-01

    Background & objectives: The human gut microbiota play a significant role in nutritional processes. The concept of probiotics has led to widespread consumption of food preparations containing probiotic microbes such as curd and yogurt. Curd prepared at home is consumed every day in most homes in southern India. In this study the home-made curd was evaluated for lactic acid bacteria (LAB) with probiotic potential. Methods: Fifteen LAB (12 lactobacilli, 1 Lactococcus, 2 Leuconostoc) and one yeast isolated from home-made curd were evaluated for resistance to acid, pepsin, pancreatin and bile salts; antimicrobial resistance; intrinsic antimicrobial activity; adherence to Caco-2 epithelial cells; ability to block pathogen adherence to Caco-2 cells; ability to inhibit interleukin (IL)-8 secretion from HT-29 epithelial cells in response to Vibrio cholerae; and ability to induce anti-inflammatory cytokine expression in THP-1 monocyte cells. Results: Lactobacillus abundance in fermenting curd peaked sharply at 12 h. Nine of the strains survived exposure to acid (pH 3.0) for at least one hour, and all strains survived in the presence of pancreatin or bile salts for 3 h. None showed haemolytic activity. All were resistant to most antimicrobials tested, but were sensitive to imipenem. Most strains inhibited the growth of Salmonella Typhimurium while five inhibited growth of V. cholerae O139. Seven strains showed adherence to Caco-2 cells ranging from 20-104 per cent of adherence of an adherent strain of Escherichia coli, but all inhibited V. cholerae adherence to Caco-2 cells by 20-100 per cent. They inhibited interleukin-8 secretion from HT-29 cells, in response to V. cholerae, by 50-80 per cent. Two strains induced IL-10 and IL-12 messenger ribonucleic acid (mRNA) expression in THP-1 cells. Interpretation & conclusions: LAB in curd had properties consistent with probiotic potential, but these were not consistent across species. LAB abundance in curd increased rapidly at 12 h of fermentation at room temperature and declined thereafter. PMID:25366201

  2. Detection and Quantification of Bacteria Involved in Aerobic and Anaerobic Ammonium Oxidation in an Ammonium-Contaminated Aquifer

    Microsoft Academic Search

    Theo H. M. Smits; Arne Hüttmann; David N. Lerner; Christof Holliger

    2009-01-01

    The aerobic and anaerobic ammonium-oxidizing bacterial guilds were studied from two multilevel samplers in an ammonium-contaminated aquifer in the UK. By end point polymerase chain reaction (PCR), the presence of betaproteobacterial ammonium-oxidizing bacteria and anaerobic ammonium-oxidizing (anammox) planctomycetes was demonstrated. The sequences of cloned anammox-specific PCR fragments had close relationships with known anammox strains. Real-time PCR was subsequently used to

  3. Sugar uptake and involved enzymatic activities by yeasts and lactic acid bacteria: their relationship with breadmaking quality.

    PubMed

    Antuña, B; Martínez-Anaya, M A

    1993-05-01

    The uptake kinetics of sugars present in wheat doughs and alpha-glucosidase as well as beta-fructosidase activities were determined in different strains of yeasts and lactic acid bacteria. These strains were previously selected according to their breadmaking quality. Saccharomyces cerevisiae (P6), Candida guilliermondii (P40), Lactobacillus plantarum (B31 and La18) and L. brevis (B21) showed good performance, while Sacch. fructuum (P43), L. cellobiosus (B37) and Enterococcus faecium (B11) yielded bread of lower quality. Leuconostoc mesenteroides (B10), when used in combination with other strains led also to high quality starters. All yeast strains used assimilated glucose, fructose and maltose, exhibiting saturable kinetics. Lactic acid bacteria showed saturable kinetics only for hexoses, whereas disaccharide uptake was linear. Sacch. cerevisiae, Leuconostoc mesenteroides, L. brevis and L. plantarum (B31) displayed better sugar uptake properties. For all the strains used alpha-glucosidase and beta-fructosidase activities were detected. The highest specific activities were found for Sacch. cerevisiae, C. guilliermondii and L. plantarum (B31). These results indicate good correlation between the parameters evaluated and the breadmaking potential of the microorganisms. PMID:8494688

  4. Identification of lactic acid bacteria from poultry feces: evidence on anti-campylobacter and anti-listeria activities.

    PubMed

    Nazef, L; Belguesmia, Y; Tani, A; Prévost, H; Drider, D

    2008-02-01

    Forty-five strains of lactic acid bacteria were isolated from poultry feces sampled from an industrial farm located in the Nantes area (France), and most of them belong to the Streptococcus or Lactobacillus genus according to the results obtained by Galerie API and molecular methods. The most representative lactic acid bacteria strains were screened for antibacterial compound production against 2 indicator organisms (Listeria innocua F and Campylobacter jejuni 11168) by means of the agar diffusion test. Strain S37, identified as Enterococcus faecalis, exhibited a clear anti-listerial activity and a slight anti-Campylobacter activity, whereas strain S42, identified as Lactobacillus reuteri, exhibited only anti-Campylobacter activity. Regarding the results of proteolytic, heat, and neutralizing treatments of supernatants from the aforementioned strains, we can conclude that antagonism observed is attributed to antimicrobial peptide or bacteriocin in the case of strain S37, whereas it is ascribable to a nonbacteriocin, likely a reuterin, in the case of strain S42. PMID:18212377

  5. Dynamics and Biodiversity of Populations of Lactic Acid Bacteria and Acetic Acid Bacteria Involved in Spontaneous Heap Fermentation of Cocoa Beans in Ghana?

    PubMed Central

    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 “Acetobacter ghanaensis” (A. syzygii-like). PMID:17277227

  6. Spontaneous organic cocoa bean box fermentations in Brazil are characterized by a restricted species diversity of lactic acid bacteria and acetic acid bacteria.

    PubMed

    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. PMID:21839382

  7. Characterization of aerobic spore-forming bacteria associated with industrial dairy processing environments and product spoilage.

    PubMed

    Lücking, Genia; Stoeckel, Marina; Atamer, Zeynep; Hinrichs, Jörg; Ehling-Schulz, Monika

    2013-09-01

    Due to changes in the design of industrial food processing and increasing international trade, highly thermoresistant spore-forming bacteria are an emerging problem in food production. Minimally processed foods and products with extended shelf life, such as milk products, are at special risk for contamination and subsequent product damages, but information about origin and food quality related properties of highly heat-resistant spore-formers is still limited. Therefore, the aim of this study was to determine the biodiversity, heat resistance, and food quality and safety affecting characteristics of aerobic spore-formers in the dairy sector. Thus, a comprehensive panel of strains (n=467), which originated from dairy processing environments, raw materials and processed foods, was compiled. The set included isolates associated with recent food spoilage cases and product damages as well as isolates not linked to product spoilage. Identification of the isolates by means of Fourier-transform infrared spectroscopy and molecular methods revealed a large biodiversity of spore-formers, especially among the spoilage associated isolates. These could be assigned to 43 species, representing 11 genera, with Bacillus cereus s.l. and Bacillus licheniformis being predominant. A screening for isolates forming thermoresistant spores (TRS, surviving 100°C, 20 min) showed that about one third of the tested spore-formers was heat-resistant, with Bacillus subtilis and Geobacillus stearothermophilus being the prevalent species. Strains producing highly thermoresistant spores (HTRS, surviving 125°C, 30 min) were found among mesophilic as well as among thermophilic species. B. subtilis and Bacillus amyloliquefaciens were dominating the group of mesophilic HTRS, while Bacillus smithii and Geobacillus pallidus were dominating the group of thermophilic HTRS. Analysis of spoilage-related enzymes of the TRS isolates showed that mesophilic strains, belonging to the B. subtilis and B. cereus groups, were strongly proteolytic, whereas thermophilic strains displayed generally a low enzymatic activity and thus spoilage potential. Cytotoxicity was only detected in B. cereus, suggesting that the risk of food poisoning by aerobic, thermoresistant spore-formers outside of the B. cereus group is rather low. PMID:23973839

  8. Isolation and Identification of Lactic Acid Bacteria Isolated from a Traditional Jeotgal Product in Korea

    Microsoft Academic Search

    Gyu Sung Cho; Hyung Ki Do

    2006-01-01

    Seventeen lactic acid bacterial strains (LAB) were isolated using MRS agar medium from Jeotgal, a Korean fermented food, purchased at the Jukdo market of Pohang. To identify the strains isolated, they were tested by examining their cell morphologies, gram-staining, catalase activity, arginine hydrolase activity, D-L lactate form and carbohydrate fermentation. According to the phenotypic characteristics, three strains were tent atively

  9. Species diversity and relative abundance of lactic acid bacteria in the milk of rhesus monkeys (Macaca mulatta)

    PubMed Central

    Jin, L.; Hinde, K.; Tao, L.

    2013-01-01

    Background Mother’s milk is a source of bacteria that influences the development of the infant commensal gut microbiota. To date, the species diversity and relative abundance of lactic acid bacteria in the milk of non-human primates have not been described. Methods Milk samples were aseptically obtained from 54 female rhesus monkeys (Macaca mulatta) at peak lactation. Following GM17 and MRS agar plating, single bacterial colonies were isolated based on difference in morphotypes, then grouped based on whole-cell protein profiles on SDS–PAGE. Bacterial DNA was isolated and the sequence the 16S rRNA gene was analyzed. Results A total of 106 strains of 19 distinct bacterial species, belonging to five genera, Bacillus, Enterococcus, Lactobacillus, Pediococcus, and Streptococcus, were identified. Conclusions Maternal gut and oral commensal bacteria may be translocated to the mammary gland during lactation and present in milk. This pathway can be an important source of commensal bacteria to the infant gut and oral cavity. PMID:20946146

  10. L-Arginine Affects Aerobic Capacity and Muscle Metabolism in MELAS (Mitochondrial Encephalomyopathy, Lactic Acidosis and Stroke-Like Episodes) Syndrome

    PubMed Central

    Rodan, Lance H.; Wells, Greg D.; Banks, Laura; Thompson, Sara; Schneiderman, Jane E.; Tein, Ingrid

    2015-01-01

    Objective To study the effects of L-arginine (L-Arg) on total body aerobic capacity and muscle metabolism as assessed by 31Phosphorus Magnetic Resonance Spectroscopy (31P-MRS) in patients with MELAS (Mitochondrial Encephalomyopathy with Lactic Acidosis and Stroke-like episodes) syndrome. Methods We performed a case control study in 3 MELAS siblings (m.3243A>G tRNAleu(UUR) in MTTL1 gene) with different % blood mutant mtDNA to evaluate total body maximal aerobic capacity (VO2peak) using graded cycle ergometry and muscle metabolism using 31P-MRS. We then ran a clinical trial pilot study in MELAS sibs to assess response of these parameters to single dose and a 6-week steady-state trial of oral L-Arginine. Results At baseline (no L-Arg), MELAS had lower serum Arg (p = 0.001). On 31P-MRS muscle at rest, MELAS subjects had increased phosphocreatine (PCr) (p = 0.05), decreased ATP (p = 0.018), and decreased intracellular Mg2+ (p = 0.0002) when compared to matched controls. With L-arginine therapy, the following trends were noted in MELAS siblings on cycle ergometry: (1) increase in mean % maximum work at anaerobic threshold (AT) (2) increase in % maximum heart rate at AT (3) small increase in VO2peak. On 31P-MRS the following mean trends were noted: (1) A blunted decrease in pH after exercise (less acidosis) (2) increase in Pi/PCr ratio (ADP) suggesting increased work capacity (3) a faster half time of PCr recovery (marker of mitochondrial activity) following 5 minutes of moderate intensity exercise (4) increase in torque. Significance These results suggest an improvement in aerobic capacity and muscle metabolism in MELAS subjects in response to supplementation with L-Arg. Intramyocellular hypomagnesemia is a novel finding that warrants further study. Classification of Evidence Class III evidence that L-arginine improves aerobic capacity and muscle metabolism in MELAS subjects. Trial Registration ClinicalTrials.gov NCT01603446. PMID:25993630

  11. Selection of lactic acid bacteria from Brazilian kefir grains for potential use as starter or probiotic cultures.

    PubMed

    Zanirati, Débora Ferreira; Abatemarco, Mário; Sandes, Sávio Henrique de Cicco; Nicoli, Jacques Robert; Nunes, Álvaro Cantini; Neumann, Elisabeth

    2015-04-01

    Brazilian kefir is a homemade fermented beverage that is obtained by incubating milk or a brown sugar solution with kefir grains that contribute their different microbiological compositions. It is highly important to isolate and characterize microorganisms from Brazilian kefir grains to obtain starter cultures for the industrial production of a standardized commercial kefir. Thus, the present study aimed to isolate lactic acid bacteria from eight kefir grains that were propagated in milk or sugar solutions from five different locations in Brazil and to select Lactobacillus isolates based on desirable in vitro probiotic properties. One hundred eight isolates from both substrates were identified by amplified ribosomal DNA restriction analysis and/or 16S rRNA gene sequencing and were determined to belong to the following 11 species from the genera: Lactococcus, Leuconostoc, Lactobacillus (L.), and Oenococcus. Leuconostoc mesenteroides, Lactobacillus kefiri, and Lactobacillus kefiranofaciens were isolated only from milk grains, whereas Lactobacillus perolens, Lactobacillus parafarraginis, Lactobacillus diolivorans, and Oenococcus oeni were isolated exclusively from sugar water grains. When the microbial compositions of four kefir grains were evaluated with culture-independent analyses, L. kefiranofaciens was observed to predominant in milk grains, whereas Lactobacillus hilgardii was most abundant in sugar water kefir. Unfortunately, L. hilgardii was not isolated from any grain, although this bacteria was detected with a culture-independent methodology. Fifty-two isolated Lactobacilli were tested for gastric juice and bile salt tolerance, antagonism against pathogens, antimicrobial resistance, and surface hydrophobicity. Three Lactobacillus strains (L. kefiranofaciens 8U, L. diolivorans 1Z, and Lactobacillus casei 17U) could be classified as potential probiotics. In conclusion, several lactic acid bacteria that could be used in combination with yeasts as starter cultures for both milk kefir and sugar water kefir were characterized, and the functional properties of several of the lactobacilli isolated from the kefir grains were suggestive of their possible use as probiotics in both kefir and other dairy products. PMID:25542841

  12. Dynamics of phosphorus and phytate-utilizing bacteria during aerobic degradation of dairy cattle dung.

    PubMed

    Fuentes, Bárbara; Jorquera, Milko; Mora, María de la Luz

    2009-01-01

    During organic wastes degradation, P is transformed which may affect its availability. In this study, the dynamics of P and the occurrence of phytate-utilizing bacteria (PUB) were evaluated during aerobic degradation of dairy cattle dung in laboratory-scale reactors for 105 d. The results showed an increase of water-soluble inorganic P (Pi) (from 570 to 1890 mg kg(-1)) and biomass P (from 390 to 870 mg kg(-1)) during the initial 40 d. After this period, water-soluble Pi remained constant (around 1500 mg kg(-1)) and biomass P decreased (around 220 mg kg(-1)) probably due to the decrease of easily available C in dung. Under the acidic conditions in the first 20 d there was an increase in concentration of Al (25 mg kg(-1)) and Fe (27 mg kg(-1)) ions. These ions were no longer detectable in the alkaline conditions occurring after 40 d. In the same period, the Ca concentration increased (from 1170 to 2370 mg kg(-1)) and chemical speciation revealed permanent association of Ca ions with Pi. Sequential P fractionation showed a decrease of organic P in NaHCO(3), NaOH and HCl fractions and an increase of residual P (25-52% with respect to total P). Analysis by (31)P NMR also showed a decrease (from 14% to 1.6%) of phytic acid content during final experimental period (60 and 105 d). The bacteriological analysis revealed various PUB involved in degradation of the dung. Two morphotypes, genetically characterized as Enterobacter and Rahnella, which were dominant under higher content of residual P, showed strong utilization of phytate in vitro. PMID:18977014

  13. Drug resistance and molecular epidemiology of aerobic bacteria isolated from puerperal infections in bangladesh.

    PubMed

    Ahmed, Salma; Kawaguchiya, Mitsuyo; Ghosh, Souvik; Paul, Shyamal Kumar; Urushibara, Noriko; Mahmud, Chand; Nahar, Kamrun; Hossain, Mohammad Akram; Kobayashi, Nobumichi

    2015-06-01

    Puerperal infection is a common complication during postnatal period in developing countries. Bacterial species, drug resistance, and genetic characteristics were investigated for a total of 470 isolates from puerperal infections in Bangladesh for a 2-year period (2010-2012). The most common species was Escherichia coli (n=98), followed by Enterococcus faecalis (n=54), Staphylococcus haemolyticus (n=33), Proteus mirabilis (n=32), Staphylococcus aureus (n=27), Klebsiella pneumoniae (n=22), and Enterobacter cloacae (n=21). S. aureus and Acinetobacter baumannii were isolated at a higher frequency from wound infections after cesarean section, while E. coli, E. cloacae, and K. pneumoniae were isolated from community-acquired endometritis and urinary tract infections. Resistance to third-generation cephalosporins was frequent for Enterobacteriacae, and was mainly mediated by blaCTX-M-1 group beta-lactamases. The CTX-M gene in E. coli from the four phylogroups was identified as blaCTX-M-15, and phylogroup B2 isolates with blaCTX-M-15 were classified into ST131 with O25b allele, harboring aac(6')-Ib-cr and various virulence factors. Carbapenemase genes blaNDM-1 and blaNDM-7 were identified in one isolate each of phylogroup A E. coli. Methicillin-resistant S. aureus isolates had type IV or V SCCmec, including isolates of ST361 (CC672), which is related to an emerging ST672 clone in the Indian subcontinent. This study revealed the recent epidemiological status of aerobic bacteria causing puerperal infections in Bangladesh, providing useful information to improve clinical practice and infection control. PMID:25555043

  14. Effectiveness of Active Packaging on Control of Escherichia Coli O157:H7 and Total Aerobic Bacteria on Iceberg Lettuce.

    PubMed

    Lu, Haixia; Zhu, Junli; Li, Jianrong; Chen, Jinru

    2015-06-01

    Contaminated leafy green vegetables have been linked to several outbreaks of human gastrointestinal infections. Antimicrobial interventions that are adoptable by the fresh produce industry for control of pathogen contamination are in great demand. This study was undertaken to evaluate the efficacy of sustained active packaging on control of Escherichia coli O157:H7 and total aerobic bacteria on lettuce. Commercial Iceberg lettuce was inoculated with a 3-strain mixture of E. coli O157:H7 at 10(2) or 10(4) CFU/g. The contaminated lettuce and un-inoculated controls were placed respectively in 5 different active packaging structures. Traditional, nonactive packaging structure was included as controls. Packaged lettuce was stored at 4, 10, or 22 °C for 3 wk and sampled weekly for the population of E. coli O157:H7 and total aerobic bacteria. Results showed that packaging structures with ClO2 generator, CO2 generator, or one of the O2 scavengers effectively controlled the growth of E. coli O157:H7 and total aerobic bacteria under all storage conditions. Packaging structure with the ClO2 generator was most effective and no E. coli O157:H7 was detected in samples packaged in this structure except for those that were inoculated with 4 log CFU/g of E. coli O157:H7 and stored at 22 °C. Packaging structures with an oxygen scavenger and the allyl isothiocyanate generator were mostly ineffective in control of the growth of the bacteria on Iceberg lettuce. The research suggests that some of the packaging structures evaluated in the study can be used to control the presence of foodborne pathogens on leafy green vegetables. PMID:25974213

  15. Influence of Vaginal Bacteria and d- and l-Lactic Acid Isomers on Vaginal Extracellular Matrix Metalloproteinase Inducer: Implications for Protection against Upper Genital Tract Infections

    PubMed Central

    Witkin, Steven S.; Mendes-Soares, Helena; Linhares, Iara M.; Jayaram, Aswathi; Ledger, William J.; Forney, Larry J.

    2013-01-01

    ABSTRACT We evaluated levels of vaginal extracellular matrix metalloproteinase inducer (EMMPRIN) and matrix metalloproteinase (MMP-8) in vaginal secretions in relation to the composition of vaginal bacterial communities and d- and l-lactic acid levels. The composition of vaginal bacterial communities in 46 women was determined by pyrosequencing the V1 to V3 region of 16S rRNA genes. Lactobacilli were dominant in 71.3% of the women, followed by Gardnerella (17.4%), Streptococcus (8.7%), and Enterococcus (2.2%). Of the lactobacillus-dominated communities, 51.5% were dominated by Lactobacillus crispatus, 36.4% by Lactobacillus iners, and 6.1% each by Lactobacillus gasseri and Lactobacillus jensenii. Concentrations of l-lactic acid were slightly higher in lactobacillus-dominated vaginal samples, but most differences were not statistically significant. d-Lactic acid levels were higher in samples containing L. crispatus than in those with L. iners (P < 0.0001) or Gardnerella (P = 0.0002). The relative proportion of d-lactic acid in vaginal communities dominated by species of lactobacilli was in concordance with the proportions found in axenic cultures of the various species grown in vitro. Levels of l-lactic acid (P < 0.0001) and the ratio of l-lactic acid to d-lactic acid (P = 0.0060), but not concentrations of d-lactic acid, were also correlated with EMMPRIN concentrations. Moreover, vaginal concentrations of EMMPRIN and MMP-8 levels were highly correlated (P < 0.0001). Taken together, the data suggest the relative proportion of l- to d-lactic acid isomers in the vagina may influence the extent of local EMMPRIN production and subsequent induction of MMP-8. The expression of these proteins may help determine the ability of bacteria to transverse the cervix and initiate upper genital tract infections. PMID:23919998

  16. Probiotic lactic acid bacteria ( Lactobacillus acidophilus HN017, Lactobacillus rhamnosus HN001 and Bifidobacterium lactis HN019) have no adverse effects on the health of mice

    Microsoft Academic Search

    Quan Shu; Joseph S Zhou; Kay J. Rutherfurd; Mervyn J Birtles; Jaya Prasad; Pramod K Gopal; Harsharnjit S Gill

    1999-01-01

    The safety of the probiotic lactic acid bacteria Lactobacillus acidophilus (HN017), Lactobacillus rhamnosus (HN001, DR20™), and Bifidobacterium lactis (HN019, DR10™), was studied in BALB\\/c mice fed with different doses (5×107, 109 or 5×1010cfu\\/mouse\\/day) of the bacteria for 7 days. No abnormal clinical signs were observed in any of the groups during the period of the experiment. There were no significant

  17. Effect of storage temperature and gas permeability of packaging film on the growth of lactic acid bacteria and Brochothrix thermosphacta in cooked meat emulsions

    Microsoft Academic Search

    O. Garroa; C. Fernandez

    The effect of gas permeability of packaging film on the growth of lactic acid bacteria and Brochothrix thermosphacta in cooked meat emulsions stored at 0, 8 and 151C was investigated. The estimated parameters from Gompertz equation for the assayed temperature-oxygen permeability combinations showed LAB development to be significantly greater than those of B. thermosphacta. The influence of the two sources

  18. Characterization of lactic acid bacteria isolated from a Greek dry-fermented sausage in respect of their technological and probiotic properties

    Microsoft Academic Search

    E. Papamanoli; N. Tzanetakis; E. Litopoulou-Tzanetaki; P. Kotzekidou

    2003-01-01

    A total of 147 lactic acid bacteria was isolated from two types of naturally fermented dry sausages at four different stages of the ripening process studied in order to select the most suitable strains according to their technological characteristics including probiotic properties and antimicrobial activity against food-borne pathogens. Identification of the isolates revealed that 90% were lactobacilli, 4% enterococci, 3%

  19. USE OF REAL TIME POLYMERASE CHAIN REACTION TO DETERMINE POPULATION PROFILES OF INDIVIDUAL SPECIES OF LACTIC ACID BACTERIA IN ALFALFA SILAGE AND STORED CORN STOVER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Real-time polymerase chain reaction (RT-PCR) was used to quantify seven species of lactic acid bacteria (LAB) in alfalfa silage prepared at laboratory scale in the presence or absence of four commercial inoculants, and corn stover harvested at different moisture levels and stored for ~9 months under...

  20. Use of unsupervised and supervised artificial neural networks for the identification of lactic acid bacteria on the basis of SDS-PAGE patterns of whole cell proteins

    Microsoft Academic Search

    P. Piraino; A. Ricciardi; G. Salzano; T. Zotta; E. Parente

    2006-01-01

    Conventional multivariate statistical techniques (hierarchical cluster analysis, linear discriminant analysis) and unsupervised (Kohonen Self Organizing Map) and supervised (Bayesian network) artificial neural networks were compared for as tools for the classification and identification of 352 SDS-PAGE patterns of whole cell proteins of lactic acid bacteria belonging to 22 species of the genera Lactobacillus, Leuconostoc, Enterococcus, Lactococcus and Streptococcus including 47

  1. Effect of lactic acid bacteria inoculant and beet pulp addition on fermentation characteristics and in vitro ruminal digestion of vegetable residue silage

    Microsoft Academic Search

    Y. Cao; Y. Cai; T. Takahashi; N. Yoshida; M. Tohno; R. Uegaki; K. Nonaka; F. Terada

    2011-01-01

    The objective of this study was to determine the effect of beet pulp (BP) and lactic acid bacteria (LAB) on silage fermentation quality and in vitro ruminal dry matter (DM) digestion of vegetable residues, including white cabbage, Chinese cabbage, red cabbage, and lettuce. Silage was prepared using a small-scale fermentation system, and treatments were designed as control silage without additive

  2. Effects of the fermentation product of herbs by lactic acid bacteria against phytopathogenic filamentous fungi and on the growth of host plants

    Microsoft Academic Search

    Shinsuke Kuwaki; Iichiro Ohhira; Masumi Takahata; Atsuko Hirota; Yoshiyuki Murata; Mikiro Tada

    2004-01-01

    The fermentation product of herbs by lactic acid bacteria (FHL) was assayed for antifungal activities against Rosellinia necatrix, Helicobasidium mompa, Fusarium oxysporum, Pythium graminicola and Pyricularia oryzae. FHL completely inhibited the growth of R. necatrix, H. mompa, P. graminicola and P. oryzae, and reduced the growth of F. oxysporum by 35%. When the seeds of Medicago sativa L. (alfalfa), Asparagus

  3. Growth and bacteriocin production by lactic acid bacteria in vegetable broth and their effectiveness at reducing Listeria monocytogenes in vitro and in fresh-cut lettuce

    Microsoft Academic Search

    Ana Allende; Beatriz Martínez; Victoria Selma; María I. Gil; Juan E. Suárez; Ana Rodríguez

    2007-01-01

    The fresh-cut fruit and vegetable industry is searching for alternatives to replace chemical treatments with biopreservative approaches that ensure the safety of the product and fulfil consumer preferences for minimally processed foods. In this study, the use of bacteriocins produced by lactic acid bacteria has been tested as a substitute for chemical disinfection of fresh-cut iceberg lettuce. First, the ability

  4. How safe is safe?--a case of Lactobacillus paracasei ssp. paracasei endocarditis and discussion of the safety of lactic acid bacteria.

    PubMed

    Soleman, Nadia; Laferl, Hermann; Kneifel, Wolfgang; Tucek, Gerhard; Budschedl, Erich; Weber, Heinz; Pichler, Hannes; Mayer, Helmut K

    2003-01-01

    We report a case of endocarditis due to Lactobacillus paracasei ssp. paracasei, which could be distinguished from Lactobacillus strains used for the fermentation of dairy products by randomly amplified polymorphic DNA-polymerase chain reaction. The safety of biotechnical lactic acid bacteria use is also discussed. PMID:14606618

  5. Isolation and Identification of Lactic Acid Bacteria Isolated from a Traditional Jeotgal Product in Korea

    Microsoft Academic Search

    Gyu Sung Cho; Hyung Ki Do

    2006-01-01

    Seventeen lactic acid bacterial strains (LAB) were isolated using MRS agar medium from Jeotgal, a Korean fermented food, purchased\\u000a at the Jukdo market of Pohang. To identify the strains isolated, they were tested by examining their cell morphologies, gram-staining,\\u000a catalase activity, arginine hydrolase activity, D-L lactate form and carbohydrate fermentation. According to the phenotypic\\u000a characteristics, three strains were tent atively

  6. Imaging of lactic acid bacteria with AFM--elasticity and adhesion maps and their relationship to biological and structural data.

    PubMed

    Schaer-Zammaretti, Prisca; Ubbink, Job

    2003-01-01

    The adhesion of lactic acid bacteria to the intestinal epithelium is one of the most important factors determining probiotic ability of a bacterial strain. Studying bacterial adhesion requires knowledge of the structure and properties of the bacterial surface, which can be studied by atomic force microscopy under native conditions. The observation of the surface topography of bacteria from the species Lactobacillus crispatus, L. helveticus and L. johnsonii shows major differences between bacteria having a crystalline-like protein layer as part of the cell wall and those without such layers. Force volume images calculated into elasticity and adhesion force maps of different bacterial strains show that L. crispatus and L. helveticus have a surface with a homogeneous stiffness with no adhesion events. This is most likely caused by the S-layer, which completely covers the surface of the bacteria. We infer that the absence of adhesion peaks is caused by the semi-crystalline character of such protein layers, in agreement with the results obtained from electron microscopy. Analysis of a number of L. johnsonii strains shows that these bacteria have surface properties which strongly differ from the L. crispatus and L. helveticus strains. For L. johnsonii DMS20533 and L. johnsonii ATCC33200 high adhesion forces are observed, which can be related to a surface rich in polysaccharides. L. johnsonii ATCC332 has lower adhesion forces compared to the other two and, furthermore, the surface topography shows depressions. We suppose that this strain has a surface pattern consisting of crystalline-like proteins alternating with polysaccharide-rich domains. The wide variety in surface properties of lactobacilli could well have wide-ranging implications for food processing and for health benefits. PMID:12801672

  7. Simultaneous and successive inoculations of yeasts and lactic acid bacteria on the fermentation of an unsulfited Tannat grape must

    PubMed Central

    Muñoz, Viviana; Beccaria, Bruno; Abreo, Eduardo

    2014-01-01

    Interactions between yeasts and lactic acid bacteria are strain specific, and their outcome is expected to change in simultaneous alcoholic - malolactic fermentations from the pattern observed in successive fermentations. One Oenococcus oeni strain Lalvin VP41™ was inoculated with two Saccharomyces cerevisiae strains either simultaneously, three days after the yeast inoculation, or when alcoholic fermentation was close to finish. Early bacterial inoculations with each yeast strain allowed for the growth of the bacterial populations, and the length of malolactic fermentation was reduced to six days. Alcoholic fermentation by Lalvin ICV D80® yeast strain left the highest residual sugar, suggesting a negative effect of the bacterial growth and malolactic activity on its performance. In sequential inoculations the bacterial populations did not show actual growth with either yeast strain. In this strategy, both yeast strains finished the alcoholic fermentations, and malolactic fermentations took longer to finish. Lalvin ICV D80® allowed for higher viability and activity of the bacterial strain than Fermicru UY4® under the three inoculation strategies. This was beneficial for the sequential completion of both fermentations, but negatively affected the completion of alcoholic fermentation by Lalvin ICV D80® in the early bacteria additions. Conversely, Fermicru UY4®, which was rather inhibitory towards the bacteria, favored the timely completion of both fermentations simultaneously. As bacteria in early inoculations with low or no SO2 addition can be expected to multiply and interact with fermenting yeasts, not only are the yeast-bacterium strains combination and time point of the inoculation to be considered, but also the amount of bacteria inoculated. PMID:24948914

  8. Simultaneous and successive inoculations of yeasts and lactic acid bacteria on the fermentation of an unsulfited Tannat grape must.

    PubMed

    Muñoz, Viviana; Beccaria, Bruno; Abreo, Eduardo

    2014-01-01

    Interactions between yeasts and lactic acid bacteria are strain specific, and their outcome is expected to change in simultaneous alcoholic--malolactic fermentations from the pattern observed in successive fermentations. One Oenococcus oeni strain Lalvin VP41™ was inoculated with two Saccharomyces cerevisiae strains either simultaneously, three days after the yeast inoculation, or when alcoholic fermentation was close to finish. Early bacterial inoculations with each yeast strain allowed for the growth of the bacterial populations, and the length of malolactic fermentation was reduced to six days. Alcoholic fermentation by Lalvin ICV D80® yeast strain left the highest residual sugar, suggesting a negative effect of the bacterial growth and malolactic activity on its performance. In sequential inoculations the bacterial populations did not show actual growth with either yeast strain. In this strategy, both yeast strains finished the alcoholic fermentations, and malolactic fermentations took longer to finish. Lalvin ICV D80® allowed for higher viability and activity of the bacterial strain than Fermicru UY4® under the three inoculation strategies. This was beneficial for the sequential completion of both fermentations, but negatively affected the completion of alcoholic fermentation by Lalvin ICV D80® in the early bacteria additions. Conversely, Fermicru UY4®, which was rather inhibitory towards the bacteria, favored the timely completion of both fermentations simultaneously. As bacteria in early inoculations with low or no SO2 addition can be expected to multiply and interact with fermenting yeasts, not only are the yeast-bacterium strains combination and time point of the inoculation to be considered, but also the amount of bacteria inoculated. PMID:24948914

  9. Malolactic fermentation of wines with immobilised lactic acid bacteria - influence of concentration, type of support material and storage conditions.

    PubMed

    Genisheva, Z; Mussatto, S I; Oliveira, J M; Teixeira, J A

    2013-06-01

    Corn cobs, grape skins and grape stems were evaluated as support materials for immobilization of the lactic acid bacteria Oenococcus oeni. The support materials with immobilized cells were further used in malolactic fermentation (MLF) of white wine. Viability of using the immobilized supports was evaluated in consecutive batch fermentations under different conditions of temperature, ethanol and SO(2). Additionally, the possibility of storage and operational stability of the immobilized supports was also studied. All the three supports presented large potential for immobilization of O. oeni cells. The consecutive batches of MLF were successfully conducted for a total period of around 5 months with the possibility of storage of the biocatalyst for 30 d in wine at 25°C. PMID:23411274

  10. Presence of erythromycin and tetracycline resistance genes in lactic acid bacteria from fermented foods of Indian origin.

    PubMed

    Thumu, Surya Chandra Rao; Halami, Prakash M

    2012-11-01

    Lactic acid bacteria (LAB) resistant to erythromycin were isolated from different food samples on selective media. The isolates were identified as Enterococcus durans, Enterococcus faecium, Enterococcus lactis, Enterococcus casseliflavus, Lactobacillus salivarius, Lactobacillus reuteri, Lactobacillus plantarum, Lactobacillus fermentum, Pediococcus pentosaceus and Leuconostoc mesenteroides. Of the total 60 isolates, 88 % harbored the ermB gene. The efflux gene msrA was identified in E. faecium, E. durans, E. lactis, E. casseliflavus, P. pentosaceus and L. fermentum. Further analysis of the msrA gene by sequencing suggested its homology to msrC. Resistance to tetracycline due to the genes tetM, tetW, tetO, tetK and tetL, alone or in combination, were identified in Lactobacillus species. The tetracycline efflux genes tetK and tetL occurred in P. pentosaceus and Enterococcus species. Since it appeared that LAB had acquired these genes, fermented foods may be a source of antibiotic resistance. PMID:22644346

  11. Comparison of mathematical models of lactic acid bacteria growth in vacuum-packaged raw beef stored at different temperatures.

    PubMed

    Li, M Y; Sun, X M; Zhao, G M; Huang, X Q; Zhang, J W; Tian, W; Zhang, Q H

    2013-04-01

    The lactic acid bacteria grown in vacuum-packaged raw beef under 7, 10, 15, and 20?°C has been studied in this paper. Four primary models, the modified Gompertz, logistic, Baranyi, and Huang model were used for data fitting. Statistical criteria such as the bias factor and accuracy factor, mean square error, Akaike's information criterion, and the residual distribution were used for comparing the models. The result showed that all of the 4 models can fit the data well and they were not significantly different in the performance. They were equally capable of describing bacterial growth, but the growth rate and lag time estimated from the modified Gompertz model were a little higher than other models. The estimate for the lag time was not accurate as the growth rate. PMID:23560997

  12. The Biodiversity of Lactic Acid Bacteria in Greek Traditional Wheat Sourdoughs Is Reflected in Both Composition and Metabolite Formation

    PubMed Central

    De Vuyst, Luc; Schrijvers, Vincent; Paramithiotis, Spiros; Hoste, Bart; Vancanneyt, Marc; Swings, Jean; Kalantzopoulos, George; Tsakalidou, Effie; Messens, Winy

    2002-01-01

    Lactic acid bacteria (LAB) were isolated from Greek traditional wheat sourdoughs manufactured without the addition of baker's yeast. Application of sodium dodecyl sulfate-polyacrylamide gel electrophoresis of total cell protein, randomly amplified polymorphic DNA-PCR, DNA-DNA hybridization, and 16S ribosomal DNA sequence analysis, in combination with physiological traits such as fructose fermentation and mannitol production, allowed us to classify the isolated bacteria into the species Lactobacillus sanfranciscensis, Lactobacillus brevis, Lactobacillus paralimentarius, and Weissella cibaria. This consortium seems to be unique for the Greek traditional wheat sourdoughs studied. Strains of the species W. cibaria have not been isolated from sourdoughs previously. No Lactobacillus pontis or Lactobacillus panis strains were found. An L. brevis-like isolate (ACA-DC 3411 t1) could not be identified properly and might be a new sourdough LAB species. In addition, fermentation capabilities associated with the LAB detected have been studied. During laboratory fermentations, all heterofermentative sourdough LAB strains produced lactic acid, acetic acid, and ethanol. Mannitol was produced from fructose that served as an additional electron acceptor. In addition to glucose, almost all of the LAB isolates fermented maltose, while fructose as the sole carbohydrate source was fermented by all sourdough LAB tested except L. sanfranciscensis. Two of the L. paralimentarius isolates tested did not ferment maltose; all strains were homofermentative. In the presence of both maltose and fructose in the medium, induction of hexokinase activity occurred in all sourdough LAB species mentioned above, explaining why no glucose accumulation was found extracellularly. No maltose phosphorylase activity was found either. These data produced a variable fermentation coefficient and a unique sourdough metabolite composition. PMID:12450829

  13. Culturing Aerobic and Anaerobic Bacteria and Mammalian Cells with a Microfluidic Differential Oxygenator

    E-print Network

    Lam, Raymond H. W.

    In this manuscript, we report on the culture of anaerobic and aerobic species within a disposable multilayer polydimethylsiloxane (PDMS) microfluidic device with an integrated differential oxygenator. A gas-filled microchannel ...

  14. Metabolite changes during natural and lactic acid bacteria fermentations in pastes of soybeans and soybean-maize blends.

    PubMed

    Ng'ong'ola-Manani, Tinna Austen; Ostlie, Hilde Marit; Mwangwela, Agnes Mbachi; Wicklund, Trude

    2014-11-01

    The effect of natural and lactic acid bacteria (LAB) fermentation processes on metabolite changes in pastes of soybeans and soybean-maize blends was studied. Pastes composed of 100% soybeans, 90% soybeans and 10% maize, and 75% soybeans and 25% maize were naturally fermented (NFP), and were fermented by lactic acid bacteria (LFP). LAB fermentation processes were facilitated through back-slopping using a traditional fermented gruel, thobwa as an inoculum. Naturally fermented pastes were designated 100S, 90S, and 75S, while LFP were designated 100SBS, 90SBS, and 75SBS. All samples, except 75SBS, showed highest increase in soluble protein content at 48 h and this was highest in 100S (49%) followed by 90SBS (15%), while increases in 100SBS, 90S, and 75S were about 12%. Significant (P < 0.05) increases in total amino acids throughout fermentation were attributed to cysteine in 100S and 90S; and methionine in 100S and 90SBS. A 3.2% increase in sum of total amino acids was observed in 75SBS at 72 h, while decreases up to 7.4% in 100SBS at 48 and 72 h, 6.8% in 100S at 48 h and 4.7% in 75S at 72 h were observed. Increases in free amino acids throughout fermentation were observed in glutamate (NFP and 75SBS), GABA and alanine (LFP). Lactic acid was 2.5- to 3.5-fold higher in LFP than in NFP, and other organic acids detected were acetate and succinate. Maltose levels were the highest among the reducing sugars and were two to four times higher in LFP than in NFP at the beginning of the fermentation, but at 72 h, only fructose levels were significantly (P < 0.05) higher in LFP than in NFP. Enzyme activities were higher in LFP at 0 h, but at 72 h, the enzyme activities were higher in NFP. Both fermentation processes improved nutritional quality through increased protein and amino acid solubility and degradation of phytic acid (85% in NFP and 49% in LFP by 72 h). PMID:25493196

  15. Preservation of acidified cucumbers with a natural preservative combination of fumaric acid and allyl isothiocyanate that target lactic acid bacteria and yeasts.

    PubMed

    Pérez-Díaz, I M; McFeeters, R F

    2010-05-01

    Without the addition of preservative compounds cucumbers acidified with 150 mM acetic acid with pH adjusted to 3.5 typically undergo fermentation by lactic acid bacteria. Fumaric acid (20 mM) inhibited growth of Lactobacillus plantarum and the lactic acid bacteria present on fresh cucumbers, but spoilage then occurred due to growth of fermentative yeasts, which produced ethanol in the cucumbers. Allyl isothiocyanate (2 mM) prevented growth of Zygosaccharomyces globiformis, which has been responsible for commercial pickle spoilage, as well as the yeasts that were present on fresh cucumbers. However, allyl isothiocyanate did not prevent growth of Lactobacillus plantarum. When these compounds were added in combination to acidified cucumbers, the cucumbers were successfully preserved as indicated by the fact that neither yeasts or lactic acid bacteria increased in numbers nor were lactic acid or ethanol produced by microorganisms when cucumbers were stored at 30 degrees C for at least 2 mo. This combination of 2 naturally occurring preservative compounds may serve as an alternative approach to the use of sodium benzoate or sodium metabisulfite for preservation of acidified vegetables without a thermal process. PMID:20546411

  16. Characterization of lactic acid bacteria isolated from Italian Bella di Cerignola table olives: selection of potential multifunctional starter cultures.

    PubMed

    Bevilacqua, Antonio; Altieri, Clelia; Corbo, Maria Rosaria; Sinigaglia, Milena; Ouoba, Labia Irène Ivette

    2010-10-01

    Lactic acid bacteria (19 isolates) from Bella di Cerignola Italian table olives were investigated for their technological and probiotic properties for the selection of multifunctional starter cultures for table olives. The bacteria were first identified by phenotyping and genotyping, then characterized for the production of biogenic amines, growth at different pH, NaCl concentrations, and temperatures. The potentiality of the bacteria to have some probiotic properties (antimicrobial activity against foodborne pathogens, survival in low pH and in the presence of bile salts, ability to adhere to the mammalian cells model IPEC-J2) was also investigated. Eighteen of the studied isolates were identified as Lactobacillus plantarum and one as Enterococcus faecalis. All bacteria were able to grow at a range of pH between 4.0 and 10.0 as well as in media supplemented with 2.5 to 7.5% of NaCl and 0.3% bile salts and survived in MRS broth acidified at pH 2.5; moreover, they inhibited significantly Escherichia coli O157:H7. The adhesion to IPEC-J2 cells was in general low to moderate (5.3 to 8.3%); however, 2 isolates of L. plantarum (c16 and c19) showed interesting higher adhesion values (up to 16%). Our results suggest that at least 3 isolates could be possible multifunctional starters for Bella di Cerignola olives: L. plantarum 16 and 19 for mainly their probiotic properties and L. plantarum 10 for mainly its technological characteristics. Practical Application: A functional starter is a microorganism exerting benefits on human health (probiotic) and able to guide a fermentation (starter). The main goal of this article was to select a functional starter for table olives. PMID:21535510

  17. A survey of culturable aerobic and anaerobic marine bacteria in de novo biofilm formation on natural substrates in St. Andrews Bay, Scotland

    Microsoft Academic Search

    Lucy Finnegan; Manuel Garcia-Melgares; Tomasz Gmerek; W. Ryan Huddleston; Alexander Palmer; Andrew Robertson; Sarah Shapiro; Shiela E. Unkles

    This study reports a novel study of marine biofilm formation comprising aerobic and anaerobic bacteria. Samples of quartz\\u000a and feldspar, minerals commonly found on the earth, were suspended 5 m deep in the North Sea off the east coast of St. Andrews,\\u000a Scotland for 5 weeks. The assemblage of organisms attached to these stones was cultivated under aerobic and anaerobic conditions\\u000a in

  18. Rapid identification, by use of the LTQ Orbitrap hybrid FT mass spectrometer, of antifungal compounds produced by lactic acid bacteria.

    PubMed

    Brosnan, Brid; Coffey, Aidan; Arendt, Elke K; Furey, Ambrose

    2012-07-01

    Fungal contamination of food causes health and economic concerns. Several species of lactic acid bacteria (LAB) have antifungal activity which may inhibit food spoilage fungi. LAB have GRAS (generally recognised as safe) status, allowing them to be safely integrated into food systems as natural food preservatives. A method is described herein that enables rapid screening of LAB cultures for 25 known antifungal compounds associated with LAB. This is the first chromatographic method developed which enables the rapid identification of a wide range of antifungal compounds by a single method with a short analysis time (23 min). Chromatographic separation was achieved on a Phenomenex Gemini C18 100A column (150 mm?×?2.0 mm; 5 ?m) by use of a mobile-phase gradient prepared from (A) water containing acetic acid (0.1%) and (B) acetonitrile containing acetic acid (0.1%), at a flow rate of 0.3 µL min(-1). The gradient involved a progressive ramp from 10-95% acetonitrile over 13 min. The LC was coupled to a hybrid LTQ Orbitrap XL fourier-transform mass spectrometer (FTMS) operated in negative ionisation mode. High mass accuracy data (<3 ppm) obtained by use of high resolution (30,000 K) enabled unequivocal identification of the target compounds. This method allows comprehensive profiling and comparison of different LAB strains and is also capable of the identification of additional compounds produced by these bacteria. PMID:22526638

  19. Genetic engineering techniques for lactic acid bacteria: construction of a stable shuttle vector and expression vector for ?-glucuronidase.

    PubMed

    Chang, Shiao-Ming; Yan, Tsong-Rong

    2014-02-01

    The shuttle vector, pUL6erm, was constructed by using a replicon from pL2, a multiple cloning site, colE1 ori, the ori of Gram-negative bacteria from vector pUC19, and the erythromycin resistance gene from pVA838 as a selection marker. pUL6erm could be transformed easily and maintained stably in Lactococcus lactis, Streptococcus thermophilus, Lactobacillus plantarum and Lactobacillus casei. Transformation assays of pUL6erm indicated that it had a narrow host range. ?-Glucuronidase was induced in the presence of 0.3 M NaCl and 50 mM glutamate and expressed at 2.4 U mg(-1) with the expression vector (pUL6erm-gadR-GUS) constructed based on pUL6erm carrying ?-glucuronidase gene wuth a chloride-inducible (gadR) expression cassette using Pgad as promoter. Therefore, pUL6erm and pUL6erm-gadR-GUS might be a safe and useful genetic tool for the improvement of lactic acid bacteria. PMID:24101246

  20. Biodiversity and ?-Aminobutyric Acid Production by Lactic Acid Bacteria Isolated from Traditional Alpine Raw Cow's Milk Cheeses

    PubMed Central

    Nardin, Tiziana; Schiavon, Silvia; Cavazza, Agostino; Larcher, Roberto; Tuohy, Kieran M.

    2015-01-01

    “Nostrano-cheeses” are traditional alpine cheeses made from raw cow's milk in Trentino-Alto Adige, Italy. This study identified lactic acid bacteria (LAB) developing during maturation of “Nostrano-cheeses” and evaluated their potential to produce ?-aminobutyric acid (GABA), an immunologically active compound and neurotransmitter. Cheese samples were collected on six cheese-making days, in three dairy factories located in different areas of Trentino and at different stages of cheese ripening (24?h, 15 days, and 1, 2, 3, 6, and 8 months). A total of 1,059 LAB isolates were screened using Random Amplified Polymorphic DNA-PCR (RAPD-PCR) and differentiated into 583 clusters. LAB strains from dominant clusters (n = 97) were genetically identified to species level by partial 16S rRNA gene sequencing. LAB species most frequently isolated were Lactobacillus paracasei, Streptococcus thermophilus, and Leuconostoc mesenteroides. The 97 dominant clusters were also characterized for their ability in producing GABA by high-performance liquid chromatography (HPLC). About 71% of the dominant bacteria clusters evolving during cheeses ripening were able to produce GABA. Most GABA producers were Lactobacillus paracasei but other GABA producing species included Lactococcus lactis, Lactobacillus plantarum, Lactobacillus rhamnosus, Pediococcus pentosaceus, and Streptococcus thermophilus. No Enterococcus faecalis or Sc. macedonicus isolates produced GABA. The isolate producing the highest amount of GABA (80.0±2.7?mg/kg) was a Sc. thermophilus. PMID:25802859

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

    PubMed

    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. PMID:25285490

  2. Phylogenetic analysis of nitric oxide reductase gene homologues from aerobic ammonia-oxidizing bacteria

    E-print Network

    Ward, Bess

    -oxidizing bacteria Karen L. Casciotti *,1 , Bess B. Ward Department of Geosciences, Princeton University, Princeton) are climatically important trace gases that are produced by both nitrifying and den- itrifying bacteria-oxidizing bacteria, including Nitrosomonas and Nitrosococcus species (i.e., both b- and c-Proteobacterial ammonia

  3. Functional milk beverage fortified with phenolic compounds extracted from olive vegetation water, and fermented with functional lactic acid bacteria.

    PubMed

    Servili, M; Rizzello, C G; Taticchi, A; Esposto, S; Urbani, S; Mazzacane, F; Di Maio, I; Selvaggini, R; Gobbetti, M; Di Cagno, R

    2011-05-14

    Functional milk beverages (FMB100 and FMB200) fortified with phenolic compounds (100 and 200mg/l) extracted from olive vegetable water, and fermented with ?-amino butyric acid (GABA)-producing (Lactobacillus plantarum C48) and autochthonous human gastro-intestinal (Lactobacillus paracasei 15N) lactic acid bacteria were manufactured. A milk beverage (MB), without addition of phenolic compounds, was used as the control. Except for a longer latency phase of FMB200, the three beverages showed an almost similar kinetic of acidification, consumption of lactose and synthesis of lactic acid. Apart from the beverage, Lb. plantarum C48 showed a decrease of ca. Log 2.52-2.24 cfu/ml during storage. The cell density of functional Lb. paracasei 15N remained always above the value of Log 8.0 cfu/ml. During fermentation, the total concentration of free amino acids markedly increased without significant (P > 0.05) differences between beverages. The concentration of GABA increased during fermentation and further storage (63.0 ± 0.6-67.0 ± 2.1mg/l) without significant (P > 0.05) differences between beverages. After fermentation, FMB100 and FMB200 showed the same phenolic composition of the phenol extract from olive vegetable water but a different ratio between 3,4-DHPEA and 3,4-DHPEA-EDA. During storage, the concentrations of 3,4-DHPEA-EDA, p-HPEA and verbascoside of both FMB100 and FMB200 decreased. Only the concentration of 3,4-DHPEA increased. As shown by SPME-GC-MS analysis, diactetyl, acetoin and, especially, acetaldehyde were the main volatile compounds found. The concentration of phenolic compounds does not interfere with the volatile composition. Sensory analyses based on triangle and paired comparison tests showed that phenolic compounds at the concentrations of 100 or 200mg/l were suitable for addition to functional milk beverages. PMID:21458095

  4. Population Dynamics and Metabolite Target Analysis of Lactic Acid Bacteria during Laboratory Fermentations of Wheat and Spelt Sourdoughs?

    PubMed Central

    Van der Meulen, Roel; Scheirlinck, Ilse; Van Schoor, Ann; Huys, Geert; Vancanneyt, Marc; Vandamme, Peter; De Vuyst, Luc

    2007-01-01

    Four laboratory sourdough fermentations, initiated with wheat or spelt flour and without the addition of a starter culture, were prepared over a period of 10 days with daily back-slopping. Samples taken at all refreshment steps were used for determination of the present microbiota. Furthermore, an extensive metabolite target analysis of more than 100 different compounds was performed through a combination of various chromatographic methods including liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. The establishment of a stable microbial ecosystem occurred through a three-phase evolution within a week, as revealed by both microbiological and metabolite analyses. Strains of Lactobacillus plantarum, Lactobacillus fermentum, Lactobacillus rossiae, Lactobacillus brevis, and Lactobacillus paraplantarum were dominating some of the sourdough ecosystems. Although the heterofermentative L. fermentum was dominating one of the wheat sourdoughs, all other sourdoughs were dominated by a combination of obligate and facultative heterofermentative taxa. Strains of homofermentative species were not retrieved in the stable sourdough ecosystems. Concentrations of sugar and amino acid metabolites hardly changed during the last days of fermentation. Besides lactic acid, ethanol, and mannitol, the production of succinic acid, erythritol, and various amino acid metabolites, such as phenyllactic acid, hydroxyphenyllactic acid, and indolelactic acid, was shown during fermentation. Physiologically, they contributed to the equilibration of the redox balance. The biphasic approach of the present study allowed us to map some of the interactions taking place during sourdough fermentation and helped us to understand the fine-tuned metabolism of lactic acid bacteria, which allows them to dominate a food ecosystem. PMID:17557853

  5. Ability of Thermophilic Lactic Acid Bacteria To Produce Aroma Compounds from Amino Acids

    Microsoft Academic Search

    Sandra Helinck; Dominique Le Bars; Daniel Moreau; Mireille Yvon

    2004-01-01

    Although a large number of key odorants of Swiss-type cheese result from amino acid catabolism, the amino acid catabolic pathways in the bacteria present in these cheeses are not well known. In this study, we compared the in vitro abilities of Lactobacillus delbrueckii subsp. lactis, Lactobacillus helveticus, and Streptococcus ther- mophilus to produce aroma compounds from three amino acids, leucine,

  6. Nitric Oxide (NO) and Lactic Acid Bacteria-Contributions to Health, Food Quality, and Safety

    Microsoft Academic Search

    Aynur Gül Karahan; M. Lütfü Çakmakçi; Buket Cicioglu-Aridogan; Arzu Kart-Gündogdu

    2005-01-01

    In this article, the effects of nitric oxide (NO) and nitric oxide producer bacteria on food quality, safety, and human health care high lighted. NO, which was previously recognized as a toxic gas, has attracted attention in the last two decades due to its vital role in many physiological processes of animals and plants. Particularly, it is important to note

  7. Isolation, identification and changes in the composition of lactic acid bacteria during the malting of two different barley cultivars.

    PubMed

    Booysena, C; Dicks, L M T; Meijering, I; Ackermann, A

    2002-06-01

    Malt has a complex microbial population, which changes as the malting process commences. Little is known about the proliferation of lactic acid bacteria (LAB) in each of the malting phases. In this study, we determined the number of LAB present in the different phases of malting with Clipper and Prisma barley cultivars. The strains were identified to species level by using numerical analysis of total soluble cell protein patterns, RAPD-PCR banding patterns and 16S rRNA sequencing. The number of viable LAB in the barley before steep was higher in Prisma than Clipper (7.6 x 10(4) and 1.2 x 10(3) cfu/g, respectively). Despite this, the number of viable cells recorded in the first steep water was slightly higher for Clipper (9.0 x 10(5) cfu/g) than Prisma (5.5 x 10(5) cfu/g). More or less, the same cell numbers were recorded for the two barley cultivars after the first and second dry stands. Both cultivars displayed more or less the same cell numbers (3.7 x 10(7) for Clipper and 3.2 x 10(7) cfu/g for Prisma) after the third day of germination. However, a higher number of LAB were detected in the kilned Prisma malt (6.9 x 10(4) cfu/g) than the Clipper malt (1.5 x 10(4) cfu/g). Leuconostoc argentinum, Le. lactis and Weissella confusa were the most predominant in both cultivars. A few strains were identified as W. paramesenteroides (four strains), Lactobacillus casei (five strains), Lactococcus lactis (five strains) and Lb. rhamnosus (two strains). Lb. casei and Lb. rhamnosus were not isolated from the Prisma cultivar, while W. paramesenteroides and Lc. lactis were absent in the Clipper cultivar. Kilned malt of the Clipper cultivar contained predominantly Le. argentinum, whereas the Prisma cultivar contained mainly Lc. lactis. To our knowledge. this is the first report of LAB in Clipper and Prisma barley and the various malting phases. The influence of the various groups of lactic acid bacteria on the fermenting ability of brewers' yeast is currently being determined. PMID:12038579

  8. The Bacillus subtilis and Lactic Acid Bacteria Probiotics Influences Intestinal Mucin Gene Expression, Histomorphology and Growth Performance in Broilers

    PubMed Central

    Aliakbarpour, H. R.; Chamani, M.; Rahimi, G.; Sadeghi, A. A.; Qujeq, D.

    2012-01-01

    The aim of the present study was to evaluate the effect of commercial monostrain and multistrain probiotics in diets on growth performance, intestinal morphology and mucin gene (MUC2) expression in broiler chicks. Three hundred seventy-eight 1-d-old male Arian broiler chicks were allocated in 3 experimental groups for 6 wk. The birds were fed on a corn-soybean based diet and depending on the addition were labeled as follows: control-unsupplemented (C), birds supplemented with Bacillus subtilis (BS) and lactic acid bacteria (LAB) based probiotics. Each treatment had 6 replicates of 21 broilers each. Treatment effects on body weight, feed intake, feed conversion ratio and biomarkers such as intestinal goblet cell density, villus length, villus width, and mucin gene expression were determined. Total feed intake did not differ significantly between control birds and those fed a diet with probiotics (p>0.05). However, significant differences in growth performance were found. Final body weight at 42 d of age was higher in birds fed a diet with probiotics compared to those fed a diet without probiotic (p<0.05). Inclusion of Bacillus subtilis based probiotic in the diets also significantly affected feed conversion rate (FCR) compared with control birds (p<0.05). No differences in growth performance were observed in birds fed different types of probiotic supplemented diets. Inclusion of lactic acid bacteria based probiotic in the diets significantly increased goblet cell number and villus length (p<0.05). Furthermore, diets with Bacillus subtilis based probiotics significantly increased gene expression (p<0.05), with higher intestinal MUC2 mRNA in birds fed diet with probiotics compared to those fed the control diet. In BS and LAB probiotic fed chicks, higher growth performance may be related to higher expression of the MUC2 gene in goblet cells and/or morphological change of small intestinal tract. The higher synthesis of the mucin gene after probiotic administration may positively affect bacterial interactions in the intestinal digestive tract, intestinal mucosal cell proliferation and consequently efficient nutrient absorption. PMID:25049692

  9. Application of Native Lactic Acid Bacteria (LAB) for Fermentative Recovery of Lipids and Proteins from Fish Processing Wastes: Bioactivities of Fermentation Products

    Microsoft Academic Search

    Amit Kumar Rai; R. Jini; H. C. Swapna; N. M. Sachindra; N. Bhaskar; V. Baskaran

    2011-01-01

    Fermentation using native lactic acid bacteria (LAB) was evaluated for its effectiveness in recovering lipids and proteins simultaneously from freshwater fish visceral waste (FVW). Five different LAB isolated from fish processing waste were employed in a fermentation process that involved 10% (w\\/w) glucose, 2% (w\\/w) NaCl, and 10% (v\\/w) LAB. Cultures evaluated included four native isolates (Pediococcus acidilactici NCIM5368, Enterococcus

  10. Antifungal activity of strains of lactic acid bacteria isolated from a semolina ecosystem against Penicillium roqueforti, Aspergillus niger and Endomyces fibuliger contaminating bakery products

    Microsoft Academic Search

    Francesca Valerio; Mara Favilla; Palmira De Bellis; Angelo Sisto; Silvia de Candia; Paola Lavermicocca

    2009-01-01

    Thirty samples of Italian durum wheat semolina and whole durum wheat semolina, generally used for the production of Southern Italy's traditional breads, were subjected to microbiological analysis in order to explore their lactic acid bacteria (LAB) diversity and to find strains with antifungal activity. A total of 125 presumptive LAB isolates (Gram-positive and catalase-negative) were characterized by repetitive extragenic palindromic-PCR

  11. Potential probiotic lactic acid bacteria Lactobacillus rhamnosus (HN001), Lactobacillus acidophilus (HN017) and Bifidobacterium lactis (HN019) do not degrade gastric mucin in vitro

    Microsoft Academic Search

    J. S. Zhou; P. K. Gopal; H. S. Gill

    2001-01-01

    The mucus layer (mucin) coating the surface of the gastrointestinal tract (GIT) plays an important role in the mucosal barrier system. Any damage or disturbance of this mucin layer will compromise the host’s mucosal defence function. In the present study, the ability of three potential probiotic lactic acid bacteria (LAB) strains (Lactobacillus rhamnosus HN001, Lactobacillus acidophilus HN017, Bifidobacterium lactis HN019)

  12. Characterization of lactic acid bacteria isolated from a Thai low-salt fermented fish product and the role of garlic as substrate for fermentation

    Microsoft Academic Search

    Christine Paludan-Müller; Hans Henrik Huss; Lone Gram

    1999-01-01

    Lactic acid bacteria (LAB) isolated from raw materials (fish, rice, garlic and banana leaves) and processed som-fak (a Thai low-salt fermented fish product) were characterized by API 50-CH and other phenotypic criteria. Lactococcus lactis subsp. lactis and Leuconostoc citreum were specifically associated with fish fillet and minced fish, Lactobacillus paracasei subsp. paracasei with boiled rice and Weisella confusa with garlic

  13. Effects of including ?1–4 galacto-oligosaccharides, lactic acid bacteria or yeast culture on methanogenesis as well as energy and nitrogen metabolism in sheep

    Microsoft Academic Search

    B Mwenya; B Santoso; C Sar; Y Gamo; T Kobayashi; I Arai; J Takahashi

    2004-01-01

    Effects of adding yeast culture (YC), lactic acid bacteria (LAB) and ?1–4 galacto-oligosaccharides (GOS) on rumen methanogenesis, energy and N utilization in sheep were evaluated. The YC (Trichosporom sericeum, (1.2–2.3) × 107 colony-forming units [cfu]\\/g), LAB (Leuconostoc mesenteroides subsp. Mesenteroides, (1.5–1.8) × 109cfu\\/g) and GOS were added to a basal diet of 40% timothy hay, 30% alfalfa hay cube and

  14. Isolation, characterization, and utilization of ?-aminobutyric acid (GABA)-producing lactic acid bacteria from Myanmar fishery products fermented with boiled rice

    Microsoft Academic Search

    Su Myo Thwe; Takeshi Kobayashi; Tianyao Luan; Takaaki Shirai; Munenaka Onodera; Naoko Hamada-Sato; Chiaki Imada

    2011-01-01

    ?-Aminobutyric acid (GABA)-producing lactic acid bacteria (LAB) were isolated from four types of Myanmar traditional fermented\\u000a fishery products with boiled rice. All of them belonged to the genus Lactobacillus, and comparison of the effects of these representatives on GABA accumulation in fermented fishery products with boiled rice\\u000a revealed that Lactobacillus farciminis D323 is the most effective strain as a starter

  15. Role of Broiler Carcasses and Processing Plant Air in Contamination of Modified-Atmosphere-Packaged Broiler Products with Psychrotrophic Lactic Acid Bacteria

    Microsoft Academic Search

    Elina Vihavainen; Hanna-Saara Lundstrom; Tuija Susiluoto; Joanna Koort; Lars Paulin; Petri Auvinen; K. Johanna Bjorkroth

    2007-01-01

    Some psychrotrophic lactic acid bacteria (LAB) are specific meat spoilage organisms in modified-atmo- sphere-packaged (MAP), cold-stored meat products. To determine if incoming broilers or the production plant environment is a source of spoilage LAB, a total of 86, 122, and 447 LAB isolates from broiler carcasses, production plant air, and MAP broiler products, respectively, were characterized using a library of

  16. Characterization and Determination of Origin of Lactic Acid Bacteria from a Sorghum-Based Fermented Weaning Food by Analysis of Soluble Proteins and Amplified Fragment Length Polymorphism Fingerprinting

    PubMed Central

    Kunene, Nokuthula F.; Geornaras, Ifigenia; von Holy, Alexander; Hastings, John W.

    2000-01-01

    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, 180 lactic acid bacterial strains isolated from sorghum powder (44 strains) and from corresponding fermented (93 strains) and cooked fermented (43 strains) porridge samples that were prepared in 15 households were characterized by using biochemical and physiological methods, as well as by analyzing the electrophoretic profiles of total soluble proteins. A total of 58 of the 180 strains were Lactobacillus plantarum strains, 47 were Leuconostoc mesenteroides strains, 25 were Lactobacillus sake-Lactobacillus curvatus strains, 17 were Pediococcus pentosaceus strains, 13 were Pediococcus acidilactici strains, and 7 were Lactococcus lactis strains. L. plantarum and L. mesenteroides strains were the dominant strains during the fermentation process and were recovered from 87 and 73% of the households, respectively. The potential origins of these groups of lactic acid bacteria were assessed by amplified fragment length polymorphism fingerprint analysis. PMID:10698775

  17. Biogenic amine synthesis in high quality Tempranillo wines. Relationship with lactic acid bacteria and vinification conditions

    Microsoft Academic Search

    Lucía Polo; Sergi Ferrer; Almudena Peña-Gallego; Purificación Hernández-Orte; Isabel Pardo

    2011-01-01

    Due to toxicological and economical concerns, there is considerable interest in establishing which enological practices promote\\u000a biogenic amine accumulation in wines. Effects of SO2 and lysozyme, malolactic fermentation (MLF) management and ageing have been studied. The type of bacteria performing MLF\\u000a and ageing proved to be the main factors influencing biogenic amine content of wine, specifically Tempranillo from Somontano\\u000a appellation

  18. Comparison of Growth Rates of Aerobic Anoxygenic Phototrophic Bacteria and Other Bacterioplankton Groups in Coastal Mediterranean Waters?

    PubMed Central

    Ferrera, Isabel; Gasol, Josep M.; Sebastián, Marta; Hojerová, Eva; Koblížek, Michal

    2011-01-01

    Growth is one of the basic attributes of any living organism. Surprisingly, the growth rates of marine bacterioplankton are only poorly known. Current data suggest that marine bacteria grow relatively slowly, having generation times of several days. However, some bacterial groups, such as the aerobic anoxygenic phototrophic (AAP) bacteria, have been shown to grow much faster. Two manipulation experiments, in which grazing, viruses, and resource competition were reduced, were conducted in the coastal Mediterranean Sea (Blanes Bay Microbial Observatory). The growth rates of AAP bacteria and of several important phylogenetic groups (the Bacteroidetes, the alphaproteobacterial groups Roseobacter and SAR11, and the Gammaproteobacteria group and its subgroups the Alteromonadaceae and the NOR5/OM60 clade) were calculated from changes in cell numbers in the manipulation treatments. In addition, we examined the role that top-down (mortality due to grazers and viruses) and bottom-up (resource availability) factors play in determining the growth rates of these groups. Manipulations resulted in an increase of the growth rates of all groups studied, but its extent differed largely among the individual treatments and among the different groups. Interestingly, higher growth rates were found for the AAP bacteria (up to 3.71 day?1) and for the Alteromonadaceae (up to 5.44 day?1), in spite of the fact that these bacterial groups represented only a very low percentage of the total prokaryotic community. In contrast, the SAR11 clade, which was the most abundant group, was the slower grower in all treatments. Our results show that, in general, the least abundant groups exhibited the highest rates, whereas the most abundant groups were those growing more slowly, indicating that some minor groups, such the AAP bacteria, very likely contribute much more to the recycling of organic matter in the ocean than what their abundances alone would predict. PMID:21724878

  19. [PH and oxidation-reduction potential change of environment during a growth of lactic acid bacteria: effects of oxidizers and reducers].

    PubMed

    Sogomonian, D; Akopian, K; Trchunian, A

    2011-01-01

    Decrease of pH and dropping of oxidation-reduction potential have been observed during growing Lactobacillus salivarius 1588 and 3823, Lactobacillus acidophilus 101E, and Lactococcus lactis 3690 in anaerobic conditions in medium with glucose acidification. These parameters and membrane proton permeability of bacteria (C(M)(H+)) changed in the mediums with different pH. Oxidizer ferrycianide and reducer DL-dithiothreitol affected the bacterial growth and their changed H+ extrusion from the cells and K+ uptake by the cells in experiment conditions. Application of oxidizers and reducers are suggested for regulation of growth related with H+ ion transport in lactic acid bacteria. PMID:21442918

  20. Diversity of lactic acid bacteria in suan-tsai and fu-tsai, traditional fermented mustard products of Taiwan.

    PubMed

    Chao, Shiou-Huei; Wu, Ruei-Jie; Watanabe, Koichi; Tsai, Ying-Chieh

    2009-11-15

    Fu-tsai and suan-tsai are spontaneously fermented mustard products traditionally prepared by the Hakka tribe of Taiwan. We chose 5 different processing stages of these products for analysis of the microbial community of lactic acid bacteria (LAB) by 16S rRNA gene sequencing. From 500 LAB isolates we identified 119 representative strains belonging to 5 genera and 18 species, including Enterococcus (1 species), Lactobacillus (11 species), Leuconostoc (3 species), Pediococcus (1 species), and Weissella (2 species). The LAB composition of mustard fermented for 3 days, known as the Mu sample, was the most diverse, with 11 different LAB species being isolated. We used sequence analysis of the 16S rRNA gene to identify the LAB strains and analysis of the dnaA, pheS, and rpoA genes to identify 13 LAB strains for which identification by 16S rRNA gene sequences was not possible. These 13 strains were found to belong to 5 validated known species: Lactobacillus farciminis, Leuconostoc mesenteroides, Leuconostoc pseudomesenteroides, Weissella cibaria, and Weissella paramesenteroides, and 5 possibly novel Lactobacillus species. These results revealed that there is a high level of diversity in LAB at the different stages of fermentation in the production of suan-tsai and fu-tsai. PMID:19700215

  1. Cultivating conditions effects on kefiran production by the mixed culture of lactic acid bacteria imbedded within kefir grains.

    PubMed

    Zajšek, Katja; Goršek, Andreja; Kolar, Mitja

    2013-08-15

    The influence of fermentation temperature, agitation rate, and additions of carbon sources, nitrogen sources, vitamins and minerals on production of kefiran by kefir grains lactic acid bacteria was studied in a series of experiments. The main aim of the work was to increase the exopolysaccharide (EPS) production where customised milk was used as fermentation medium. It was proved that the controlling of culturing conditions and the modifying of fermentation medium conditions (i.e., carbon, nitrogen, mineral sources and vitamins) can dramatically enhance the production of the EPS. The temperature and agitation rate were critical for kefiran production during the 24 h cultivation of grains; our optimised conditions being 25°C and 80 rpm, respectively. In addition, when optimising the effects of additional nutrition, it was found that 5% (w/v) lactose, 0.1% (w/v) thiamine, and 0.1% (w/v) FeCl3 led to the maximal production of EPS. The results indicate that nutrients can be utilised to improve the production of EPS and that good kefir grains growth does not appear to be a determining factor for a high production yield of EPS. PMID:23561198

  2. Screening of lactic acid bacteria from Indonesia reveals glucansucrase and fructansucrase genes in two different Weissella confusa strains from soya.

    PubMed

    Malik, Amarila; Radji, Maksum; Kralj, Slavko; Dijkhuizen, Lubbert

    2009-11-01

    Homopolysaccharide (glucan and fructan) synthesis from sucrose by sucrase enzymes in lactic acid bacteria (LAB) has been well studied in the genera Leuconostoc, Streptococcus and Lactobacillus. This study aimed to identify and characterize genes encoding glucansucrase/glucosyltransferase (GTF) and fructansucrases/fructosyltransferase (FTF) enzymes from genomic DNA of 'rare' Indonesian exopolysaccharide-producing LAB. From a total of 63 exopolysaccharide-producing LAB isolates obtained from foods, beverages and environmental samples, 18 isolates showing the most slimy and mucoid colony morphologies on sucrose were chosen for further study. By comparing bacterial growth on De Man, Rogosa and Sharpe (MRS)-sucrose with that on MRS-raffinose, and using the results of a previous PCR screening study with degenerate primer pairs targeting the conserved catalytic domain of GTFs, various strains were identified as producers of fructan (13), of glucan only (five) or as potential producers of both glucan and fructan (nine). Here, we report the characteristics of three gtf genes and one ftf gene obtained from Weissella confusa strains MBF8-1 and MBF8-2. Strain MBF8-1 harbored two putative gtf genes with high sequence similarity to GTFB of Lactobacillus reuteri 121 and GTF180 of L. reuteri 180, respectively. Strain MBF8-2 possessed single gtf and ftf genes with high sequence similarity to GTFKg3 of Lactobacillus fermentum Kg3 and DSRWC of Weissella cibaria, and FTF levansucrase of L. reuteri 121, respectively. PMID:19758326

  3. Dynamics of indigenous lactic acid bacteria populations in wine fermentations from La Rioja (Spain) during three vintages.

    PubMed

    González-Arenzana, Lucía; López, Rosa; Santamaría, Pilar; Tenorio, Carmen; López-Alfaro, Isabel

    2012-01-01

    Diversity of lactic acid bacteria (LAB) species has been analyzed for three consecutive years (2006, 2007, and 2008) during alcoholic and malolactic fermentations of Tempranillo wine in a winery at La Rioja. The results showed differences in malolactic fermentation duration, and in both diversity of LAB species and diversity of Oenococcus oeni genotypes. O. oeni was shown to be the predominant species (73% of total isolates). Monitoring the different strains of O. oeni using pulsed-field gel electrophoresis of chromosomal DNA digested with SfiI and ApaI allowed detection of a total of 37 distinct genotypes, most of them comprised at least two isolates. Six appeared in more than one vintage, one of them being present in the three studied years. Moreover, four genotypes were indistinct of the strains isolated from the air of this same winery in 2007 vintage. The frequency of participation of each genotype varied from year to year, thus dominant genotypes at one year were minority or not present at another year. This suggests that distinct indigenous O. oeni strains are better adapted to the different winery conditions every year. Predominant genotypes that appeared in more than one vintage and lead to quality wines with low histamine contents could be considered as interesting for selecting of new malolactic starter cultures. PMID:21779812

  4. Assessment of the sequential simulated gastrointestinal tolerance of lactic acid bacteria from kefir grains by response surface methodology.

    PubMed

    Zhou, Tong; Li, Bo; Peng, Cheng; Ji, Bao-Ping; Chen, Gang; Ren, Ya-Li

    2009-08-01

    The tolerance of lactic acid bacteria (LAB) from kefir grains to gastrointestinal tract conditions was evaluated in vitro. The effects of pH values and bile salts on the viability of LAB were investigated. The results demonstrated that pH value showed a significant effect on the viability. The viable counts exhibited a reduction of 1.5 to 2 log cycles in 0.3% to 0.5% bile salts after 4 h. The viability of LAB exposure to sequential simulated gastric and intestinal juices was assessed by response surface model (RSM). RSM indicated that the gastric pH and gastric contact time significantly affected the viability (P < 0.05), while the effect of intestinal contact time was not significant. Moreover, RSM revealed the interactions of pH and gastric contact time, and of pH and intestinal contact time. The LAB cells, temporarily damaged by the low pH of gastric juice (pH < 2), could recover in the intestinal juice; and the longer the intestinal contact time, the higher the viability of LAB. RSM proved to be a useful and accurate method to predict the viability of LAB under certain laboratory conditions by the model validation. This study indicated that LAB from kefir grains exhibited excellent tolerance to sequential simulated gastrointestinal tract conditions, and that kefiran possessed a significant protective effect on LAB in hostile environments. PMID:19723219

  5. Plant-based Paste Fermented by Lactic Acid Bacteria and Yeast: Functional Analysis and Possibility of Application to Functional Foods.

    PubMed

    Kuwaki, Shinsuke; Nakajima, Nobuyoshi; Tanaka, Hidehiko; Ishihara, Kohji

    2012-01-01

    A plant-based paste fermented by lactic acid bacteria and yeast (fermented paste) was made from various plant materials. The paste was made of fermented food by applying traditional food-preservation techniques, that is, fermentation and sugaring. The fermented paste contained major nutrients (carbohydrates, proteins, and lipids), 18 kinds of amino acids, and vitamins (vitamin A, B1, B2, B6, B12, E, K, niacin, biotin, pantothenic acid, and folic acid). It contained five kinds of organic acids, and a large amount of dietary fiber and plant phytochemicals. Sucrose from brown sugar, used as a material, was completely resolved into glucose and fructose. Some physiological functions of the fermented paste were examined in vitro. It was demonstrated that the paste possessed antioxidant, antihypertensive, antibacterial, anti-inflammatory, anti-allergy and anti-tyrosinase activities in vitro. It was thought that the fermented paste would be a helpful functional food with various nutrients to help prevent lifestyle diseases. PMID:25114554

  6. Influence of Geographical Origin and Flour Type on Diversity of Lactic Acid Bacteria in Traditional Belgian Sourdoughs? †

    PubMed Central

    Scheirlinck, Ilse; Van der Meulen, Roel; Van Schoor, Ann; Vancanneyt, Marc; De Vuyst, Luc; Vandamme, Peter; Huys, Geert

    2007-01-01

    A culture-based approach was used to investigate the diversity of lactic acid bacteria (LAB) in Belgian traditional sourdoughs and to assess the influence of flour type, bakery environment, geographical origin, and technological characteristics on the taxonomic composition of these LAB communities. For this purpose, a total of 714 LAB from 21 sourdoughs sampled at 11 artisan bakeries throughout Belgium were subjected to a polyphasic identification approach. The microbial composition of the traditional sourdoughs was characterized by bacteriological culture in combination with genotypic identification methods, including repetitive element sequence-based PCR fingerprinting and phenylalanyl-tRNA synthase (pheS) gene sequence analysis. LAB from Belgian sourdoughs belonged to the genera Lactobacillus, Pediococcus, Leuconostoc, Weissella, and Enterococcus, with the heterofermentative species Lactobacillus paralimentarius, Lactobacillus sanfranciscensis, Lactobacillus plantarum, and Lactobacillus pontis as the most frequently isolated taxa. Statistical analysis of the identification data indicated that the microbial composition of the sourdoughs is mainly affected by the bakery environment rather than the flour type (wheat, rye, spelt, or a mixture of these) used. In conclusion, the polyphasic approach, based on rapid genotypic screening and high-resolution, sequence-dependent identification, proved to be a powerful tool for studying the LAB diversity in traditional fermented foods such as sourdough. PMID:17675431

  7. Prevalence and impact of single-strain starter cultures of lactic acid bacteria on metabolite formation in sourdough.

    PubMed

    Ravyts, Frédéric; De Vuyst, Luc

    2011-09-01

    Flavour of type II sourdoughs is influenced by the ingredients, processing conditions, and starter culture composition. It is, however, not fully clear to what extent different sourdough lactic acid bacteria (LAB) contribute to flavour. Therefore, two types of flour (rye and wheat) and different LAB starter culture strains were used to prepare sourdoughs, thereby leaving the yeast microbiota uncontrolled. All LAB starter culture strains tested were shown to be prevalent and to acidify the flour/water mixture to pH values between 3.1 and 3.9 after 24h of fermentation. Multiple aldehydes, alcohols, ketones, and carboxylic acids were produced by the sourdough-associated microbiota throughout the fermentation period. Based on the organoleptic evaluation of breads produced with these sourdoughs, five LAB strains were selected to perform prolonged wheat and rye fermentations as to their capacity to result in an acidic (Lactobacillus fermentum IMDO 130101, Lactobacillus plantarum IMDO 130201, and Lactobacillus crustorum LMG 23699), buttermilk-like (Lactobacillus amylovorus DCE 471), or fruity flavour (Lactobacillus sakei CG1). Upon prolonged fermentation, higher metabolite concentrations were produced. For instance, L. sakei CG1 produced the highest amounts of 3-methyl-1-butanol, which was further converted into 3-methylbutyl acetate. The latter compound resulted in a fruity banana flavour after 48h of fermentation, probably due to yeast interference. Rye fermentations resulted in sourdoughs richer in volatiles than wheat, including 3-methyl-1-butanol, 2-phenylethanol, and ethyl acetate. PMID:21645811

  8. Probiotic lactic acid bacteria in the gastro-intestinal tract: health benefits, safety and mode of action.

    PubMed

    Dicks, L M T; Botes, M

    2010-03-01

    Lactic acid bacteria (LAB) have received considerable attention as probiotics over the past few years. This concept has grown from traditional dairy products to a profitable market of probiotic health supplements and functional foods. Extensive research is done on novel potential probiotic strains, with specific emphasis on their health benefits and mode of action. Criteria for the selection of probiotic strains have only recently been formulated by the Food and Agriculture Organization of the United Nations and the World Health Organization (FAO/WHO). Several in vitro techniques have been developed to evaluate the probiotic properties of strains. In many cases, this is followed by in vivo tests. Safety studies are also obligatory, as a few cases of bacteremia caused by LAB have been reported. This review focuses on the health benefits and safety of LAB probiotics, the criteria used to select a probiotic, mode of action and the impact these organisms have on natural microbiota in the gastro-intestinal tract. PMID:21831747

  9. Potential of bacteriocin-producing lactic acid bacteria for safety improvements of traditional Thai fermented meat and human health.

    PubMed

    Swetwiwathana, Adisorn; Visessanguan, Wonnop

    2015-11-01

    Lactic acid bacteria (LAB) are very important in converting of agricultural products into safe, delicious and shelf stable foods for human consumption. The preservative activity of LAB in foods is mainly attributed to the production of anti-microbial metabolites such as organic acids and bacteriocins which enables them to grow and control the growth of pathogens and spoilage microorganisms. Besides ensuring safety, bacteriocin-producing LAB with their probiotic potentials could also be emerging as a means to develop functional meat products with desirable health benefits. Nevertheless, to be qualified as a candidate probiotic culture, other prerequisite probiotic properties of bacteriocin-producing LAB have to be assessed according to regulatory guidelines for probiotics. Nham is an indigenous fermented sausage of Thailand that has gained popularity and acceptance among Thais. Since Nham is made from raw meat and is usually consumed without cooking, risks due to undesirable microorganisms such as Salmonella spp., Staphylococcus aureus, and Listeria monocytogenes, are frequently observed. With an ultimate goal to produce safer and healthier product, our research attempts on the development of a variety of new Nham products are discussed. PMID:26100576

  10. Lactic acid bacteria colonization and clinical outcome after probiotic supplementation in conventionally treated bacterial vaginosis and vulvovaginal candidiasis.

    PubMed

    Ehrström, Sophia; Daroczy, Katalin; Rylander, Eva; Samuelsson, Carolina; Johannesson, Ulrika; Anzén, Bo; Påhlson, Carl

    2010-09-01

    This randomized double-blind placebo controlled study assessed the vaginal colonization of lactic acid bacteria and clinical outcome. Vaginal capsules containing L gasseri LN40, Lactobacillus fermentum LN99, L. casei subsp. rhamnosus LN113 and P. acidilactici LN23, or placebos were administered for five days to 95 women after conventional treatment of bacterial vaginosis and/or vulvovaginal candidiasis. Vulvovaginal examinations and vaginal samplings were performed before and after administration, after the first and second menstruation, and after six months. Presence of LN strains was assessed using RAPD analysis. LN strains were present 2-3 days after administration in 89% of the women receiving LN strains (placebo: 0%, p < 0.0001). After one menstruation 53% were colonized by at least one LN strain. Nine percent were still colonized six months after administration. Ninety-three percent of the women receiving LN strains were cured 2-3 days after administration (placebo: 83%), and 78% after one menstruation (placebo: 71%) (ns). The intervention group experienced less malodorous discharge 2-3 days after administration (p = 0.03) and after the second menstruation (p = 0.04), compared with placebo. In summary, five days of vaginal administration of LN strains after conventional treatment of bacterial vaginosis and/or vulvovaginal candidiasis lead to vaginal colonization, somewhat fewer recurrences and less malodorous discharge. PMID:20472091

  11. Oral lactic acid bacteria related to the occurrence and/or progression of dental caries in Japanese preschool children.

    PubMed

    Shimada, Ayumi; Noda, Masafumi; Matoba, Yasuyuki; Kumagai, Takanori; Kozai, Katsuyuki; Sugiyama, Masanori

    2015-01-01

    Previous studies have demonstrated that the presence of lactic acid bacteria (LAB), especially those classified into the genus Lactobacillus, is associated with the progression of dental caries in preschool children. Nevertheless, the kinds of species of LAB and the characteristics that are important for dental caries have been unclear. The aims of this study were: (1) to investigate the distribution of oral LAB among Japanese preschool children with various prevalence levels of caries; and (2) to reveal the characteristics of these isolated LAB species. Seventy-four Japanese preschool children were examined for caries scores and caries progression, and their dental cavity samples were collected for LAB isolation and identification. The saliva-induced agglutination rate and the resistance to acidic environments of the identified strains were measured. Statistical analysis showed that preschool children carrying Lactobacillus (L.) salivarius or Streptococcus mutans have a significantly higher prevalence of dental caries, the growth ability in acidic environments correlates with the caries scores of individuals with L. salivarius, and the caries scores exhibit positive correlation with saliva-induced agglutination in L. salivarius. These results show that specific Lactobacillus species are associated with dental caries based on the level of carious lesion severity. The present study suggests that these specific Lactobacillus species, especially those with easily agglutinated properties and acid resistance, affect the dental caries scores of preschool children, and that these properties may provide useful information for research into the prevention of dental caries. PMID:25918670

  12. A comparison of fluorescent stains for the assessment of viability and metabolic activity of lactic acid bacteria.

    PubMed

    Zotta, T; Guidone, A; Tremonte, P; Parente, E; Ricciardi, A

    2012-03-01

    Lactic acid bacteria (LAB) are used as starter or probiotic cultures in the food and pharmaceutical industries and, therefore, rapid and accurate methods for the detection of their viability are of practical relevance. In this study 10 LAB strains, belonging to the genera Enterococcus, Lactococcus, Leuconostoc, Lactobacillus, Streptococcus and Weissella, were subjected to heat and oxidative stresses and cell injury or death was assessed comparing different fluorescent probes (Syto 9; Propidium Iodide, PI; 4,6-diamidino-2-phenylindole, DAPI; 5,(6)-carboxyfluorescein diacetate, cFDA) to identify the stain combination which most reliably allowed the detection of live/metabolically active and dead cells. Protocols for specimen preparation and staining were optimized and a simple procedure for automated cell counts was developed using NIH ImageJ macros. Cysteine and semi-solid agar solution were efficiently used as anti-fading agent and mounting medium, respectively. The double staining cFDA-PI apparently offered the best and most versatile indication of both cell metabolic activity and membrane integrity. An excellent correlation between manual and automated cell counts for the majority of strain/stain combinations was found. This work provides a simple protocol for specimen preparation and staining based on the use of safe, easy to prepare and inexpensive reagents as compared to other methods. Additionally, the automated cell count procedure developed can be applied to several bacterial species and allows an increase in the number of experimental trials and the reproducibility and sensitivity of the analysis. PMID:22805812

  13. Molecular and technological characterization of lactic acid bacteria from traditional fermented sausages of Basilicata region (Southern Italy).

    PubMed

    Bonomo, M G; Ricciardi, A; Zotta, T; Parente, E; Salzano, G

    2008-12-01

    Lactic acid bacteria (LAB) from traditional fermented sausages of the Basilicata region were investigated by ARDRA-PCR and RAPD-PCR for taxonomic identification at species and strain level and characterized on the basis of the growth and acidification at different temperatures, incubation times, levels of NaCl and KNO(2), hydrolysis of sarcoplasmatic and myofibrillar proteins and antimicrobial, peptide/amino acid release and nitrate reductase activities. Lactobacillus sakei was the predominant species (67%) followed by Pediococcus pentosaceus (16%), Leuconostoc carnosum (8%), Lactobacillus plantarum (4%), Lactobacillus brevis (2%) and Leuconostoc pseudomesenteroides (2%). The technological characterization revealed that most of the isolates had good acidifying and proteolytic properties. Moreover, Lb. sakei strains showed antimicrobial ability, while Leuconostoc strains the highest reduction of nitrates. This work was a preliminary study in the formulation of autochthonous starter cultures in order to standardize the production process of sausages, to preserve their typical organoleptic and sensory characteristics and to improve the quality of final product. PMID:22063864

  14. Modulation of peanut-induced allergic immune responses by oral lactic acid bacteria-based vaccines in mice.

    PubMed

    Ren, Chengcheng; Zhang, Qiuxiang; Wang, Gang; Ai, Chunqing; Hu, Mengsha; Liu, Xiaoming; Tian, Fengwei; Zhao, Jianxin; Chen, Yongquan; Wang, Miao; Zhang, Hao; Chen, Wei

    2014-01-01

    Peanut allergy (PNA) has becoming a non-negligible health concern worldwide. Thus far, allergen-specific immunotherapy aimed at inducing mucosal tolerance has widely been regarded as a major management strategy for PNA. The safety profiles and the intrinsic probiotic properties of lactic acid bacteria (LAB) render them attractive delivery vehicles for mucosal vaccines. In the present study, we exploited genetically modified Lactococcus lactis to produce peanut allergen Ara h 2 via different protein-targeting systems and their immunomodulatory potency for allergic immune responses in mice were investigated. By comparison with the strain expressing the cytoplasmic form of Ara h 2 (LL1), the strains expressing the secreted and anchored forms of Ara h 2 (LL2 and LL3) were more potent in redirecting a Th2-polarized to a non-allergic Th1 immune responses. Induction of SIgA and regulatory T cells were also observed at the local levels by orally administration of recombinant L. lactis. Our results indicate that allergen-producing L. lactis strains modulated allergic immune responses and may be developed as promising mucosal vaccines for managing allergic diseases. PMID:24770368

  15. Current Review of Genetically Modified Lactic Acid Bacteria for the Prevention and Treatment of Colitis Using Murine Models

    PubMed Central

    de Moreno de LeBlanc, Alejandra; Chatel, Jean-Marc; Miyoshi, Anderson; Langella, Philippe; Bermúdez-Humarán, Luis G.

    2015-01-01

    Inflammatory Bowel Diseases (IBD) are disorders of the gastrointestinal tract characterized by recurrent inflammation that requires lifelong treatments. Probiotic microorganisms appear as an alternative for these patients; however, probiotic characteristics are strain dependent and each probiotic needs to be tested to understand the underlining mechanisms involved in their beneficial properties. Genetic modification of lactic acid bacteria (LAB) was also described as a tool for new IBD treatments. The first part of this review shows different genetically modified LAB (GM-LAB) described for IBD treatment since 2000. Then, the two principally studied strategies are discussed (i) GM-LAB producing antioxidant enzymes and (ii) GM-LAB producing the anti-inflammatory cytokine IL-10. Different delivery systems, including protein delivery and DNA delivery, will also be discussed. Studies show the efficacy of GM-LAB (using different expression systems) for the prevention and treatment of IBD, highlighting the importance of the bacterial strain selection (with anti-inflammatory innate properties) as a promising alternative. These microorganisms could be used in the near future for the development of therapeutic products with anti-inflammatory properties that can improve the quality of life of IBD patients.

  16. Inhibition of Helicobacter pylori by Fermented Milk and Soymilk Using Select Lactic Acid Bacteria and Link to Enrichment of Lactic Acid and Phenolic Content

    Microsoft Academic Search

    E. Apostolidis; Y. I. Kwon; Rahul Shinde; Reza Ghaedian; K. Shetty

    2011-01-01

    Ulcer-associated dyspepsia is caused by infection with Helicobacter pylori which is linked to the majority of peptic ulcers. Antibiotic treatment does not always inhibit or kill H. pylori with potential for antibiotic resistance. The objective of this study was to determine the potential of lactic acid bacterial fermented milk and soymilk products to inhibit H. pylori. All fermented product extracts

  17. Decarboxylation of Substituted Cinnamic Acids by Lactic Acid Bacteria Isolated during Malt Whisky Fermentation

    PubMed Central

    van Beek, Sylvie; Priest, Fergus G.

    2000-01-01

    Seven strains of Lactobacillus isolated from malt whisky fermentations and representing Lactobacillus brevis, L. crispatus, L. fermentum, L. hilgardii, L. paracasei, L. pentosus, and L. plantarum contained genes for hydroxycinnamic acid (p-coumaric acid) decarboxylase. With the exception of L. hilgardii, these bacteria decarboxylated p-coumaric acid and/or ferulic acid, with the production of 4-vinylphenol and/or 4-vinylguaiacol, respectively, although the relative activities on the two substrates varied between strains. The addition of p-coumaric acid or ferulic acid to cultures of L. pentosus in MRS broth induced hydroxycinnamic acid decarboxylase mRNA within 5 min, and the gene was also induced by the indigenous components of malt wort. In a simulated distillery fermentation, a mixed culture of L. crispatus and L. pentosus in the presence of Saccharomyces cerevisiae decarboxylated added p-coumaric acid more rapidly than the yeast alone but had little activity on added ferulic acid. Moreover, we were able to demonstrate the induction of hydroxycinnamic acid decarboxylase mRNA under these conditions. However, in fermentations with no additional hydroxycinnamic acid, the bacteria lowered the final concentration of 4-vinylphenol in the fermented wort compared to the level seen in a pure-yeast fermentation. It seems likely that the combined activities of bacteria and yeast decarboxylate p-coumaric acid and then reduce 4-vinylphenol to 4-ethylphenol more effectively than either microorganism alone in pure cultures. Although we have shown that lactobacilli participate in the metabolism of phenolic compounds during malt whisky fermentations, the net result is a reduction in the concentrations of 4-vinylphenol and 4-vinylguaiacol prior to distillation. PMID:11097909

  18. Comparative analysis of the diversity of aerobic spore-forming bacteria in raw milk from organic and conventional dairy farms.

    PubMed

    Coorevits, An; De Jonghe, Valerie; Vandroemme, Joachim; Reekmans, Rieka; Heyrman, Jeroen; Messens, Winy; De Vos, Paul; Heyndrickx, Marc

    2008-06-01

    Bacterial contamination of raw milk can originate from different sources: air, milking equipment, feed, soil, faeces and grass. It is hypothesized that differences in feeding and housing strategies of cows may influence the microbial quality of milk. This assumption was investigated through comparison of the aerobic spore-forming flora in milk from organic and conventional dairy farms. Laboratory pasteurized milk samples from five conventional and five organic dairy farms, sampled in late summer/autumn and in winter, were plated on a standard medium and two differential media, one screening for phospholipolytic and the other for proteolytic activity of bacteria. Almost 930 isolates were obtained of which 898 could be screened via fatty acid methyl ester analysis. Representative isolates were further analysed using 16S rRNA gene sequencing and (GTG)(5)-PCR. The majority of aerobic spore-formers in milk belonged to the genus Bacillus and showed at least 97% 16S rRNA gene sequence similarity with type strains of Bacillus licheniformis, Bacillus pumilus, Bacillus circulans, Bacillus subtilis and with type strains of species belonging to the Bacillus cereus group. About 7% of all isolates may belong to possibly new spore-forming taxa. Although the overall diversity of aerobic spore-forming bacteria in milk from organic vs. conventional dairy farms was highly similar, some differences between both were observed: (i) a relatively higher number of thermotolerant organisms in milk from conventional dairy farms compared to organic farms (41.2% vs. 25.9%), and (ii) a relatively higher number of B. cereus group organisms in milk from organic (81.3%) and Ureibacillus thermosphaericus in milk from conventional (85.7%) dairy farms. One of these differences, the higher occurrence of B. cereus group organisms in milk from organic dairy farms, may be linked to differences in housing strategy between the two types of dairy farming. However, no plausible clarification was found for the relatively higher number of thermotolerant organisms and the higher occurrence of U. thermosphaericus in milk from conventional dairy farms. Possibly this is due to differences in feeding strategy but no decisive indications were found to support this assumption. PMID:18406093

  19. Occurrence and activity of sulphate reducing bacteria in aerobic activated sludge systems.

    PubMed

    van den Brand, T P H; Roest, K; Chen, G H; Brdjanovic, D; van Loosdrecht, M C M

    2015-03-01

    In the sewage or wastewater treatment plant, biological sulphate reduction can occur spontaneously or be applied beneficially for its treatment. The results of this study can be applied to control SRB in the sewage and WWTP. Therefore, population diversity analyses of SRB for nine activated sludge wastewater treatment plants (WWTP) in the Netherlands and the effect of long-term (months) oxygen exposures on the SRB activity were carried out. T-RFLP and clone sequencing analyses of winter and summer samples revealed that (1) all WWTP have a similar SRB population, (2) there is no seasonal impact (10-20 °C) on the SRB population present in the WWTP and (3) Desulfobacter postgatei, Desulfovibrio desulfuricans and Desulfovibrio intestinalis were the most common and dominant SRB species observed in these samples, and origin from the sewage. Short term activity tests demonstrated that SRB were not active in the aerobic WWTP, but while flushed with N2-gas SRB became slightly active after 3 h. In a laboratory reactor at a dissolved oxygen concentration of <2 %, sulphate reduction occurred and 89 % COD removal was achieved. SRB grew in granules, in order to protect themselves for oxygen exposures. SRB are naturally present in aerobic WWTP, which is due to the formation of granules. PMID:25649202

  20. Colonization by aerobic bacteria in karst: laboratory and in situ experiments.

    PubMed

    Personné, J C; Poty, F; Mahler, B J; Drogue, C

    2004-01-01

    Experiments were carried out to investigate the potential for bacterial colonization of different substrates in karst aquifers and the nature of the colonizing bacteria. Laboratory batch experiments were performed using limestone and PVC as substrates, a natural bacterial isolate and a known laboratory strain (Escherichia coli [E. coli]) as inocula, and karst ground water and a synthetic formula as growth media. In parallel, fragments of limestone and granite were submerged in boreholes penetrating two karst aquifers for more than one year; the boreholes are periodically contaminated by enteric bacteria from waste water. Once a month, rock samples were removed and the colonizing bacteria quantified and identified. The batch experiments demonstrated that the natural isolate and E. coli both readily colonized limestone surfaces using karst ground water as the growth medium. In contrast, bacterial colonization of both the limestone and granite substrates, when submerged in the karst, was less intense. More than 300 bacterial strains were isolated over the period sampled, but no temporal pattern in colonization was seen as far as strain, and colonization by E. coli was notably absent, although strains of Salmonella and Citrobacter were each observed once. Samples suspended in boreholes penetrating highly fractured zones were less densely colonized than those in the borehole penetrating a less fractured zone. The results suggest that contamination of karst aquifers by enteric bacteria is unlikely to be persistent. We hypothesize that this may be a result of the high flow velocities found in karst conduits, and of predation of colonizing bacteria by autochthonous zooplankton. PMID:15318775

  1. Colonization by aerobic bacteria in karst: Laboratory and in situ experiments

    USGS Publications Warehouse

    Personne, J.-C.; Poty, F.; Mahler, B.J.; Drogue, C.

    2004-01-01

    Experiments were carried out to investigate the potential for bacterial colonization of different substrates in karst aquifers and the nature of the colonizing bacteria. Laboratory batch experiments were performed using limestone and PVC as substrates, a natural bacterial isolate and a known laboratory strain (Escherichia coli [E. coli]) as inocula, and karst ground water and a synthetic formula as growth media. In parallel, fragments of limestone and granite were submerged in boreholes penetrating two karst aquifers for more than one year; the boreholes are periodically contaminated by enteric bacteria from waste water. Once a month, rock samples were removed and the colonizing bacteria quantified and identified. The batch experiments demonstrated that the natural isolate and E. coli both readily colonized limestone surfaces using karst ground water as the growth medium. In contrast, bacterial colonization of both the limestone and granite substrates, when submerged in the karst, was less intense. More than 300 bacterial strains were isolated over the period sampled, but no temporal pattern in colonization was seen as far as strain, and colonization by E. coli was notably absent, although strains of Salmonella and Citrobacter were each observed once. Samples suspended in boreholes penetrating highly fractured zones were less densely colonized than those in the borehole penetrating a less fractured zone. The results suggest that contamination of karst aquifers by enteric bacteria is unlikely to be persistent. We hypothesize that this may be a result of the high flow velocities found in karst conduits, and of predation of colonizing bacteria by autochthonous zooplankton.

  2. Summer distribution and diversity of aerobic anoxygenic phototrophic bacteria in the Mediterranean Sea in relation to environmental variables.

    PubMed

    Lehours, Anne-Catherine; Cottrell, Matthew T; Dahan, Océane; Kirchman, David L; Jeanthon, Christian

    2010-11-01

    Aerobic anoxygenic phototrophic bacteria (AAP) represent an important fraction of bacterioplankton assemblages in various oceanic regimes. Although their abundance and distribution have been explored recently in diverse oceanic regions, the environmental factors controlling the population structure and diversity of these photoheterotrophic bacteria remain poorly understood. Here, we investigate the horizontal and vertical distributions and the genetic diversity of AAP populations collected in late summer throughout the Mediterranean Sea using pufM-temporal temperature gel gradient electrophoresis (TTGE) and clone library analyses. The TTGE profiles and clone libraries analyzed using multivariate statistical methods demonstrated a horizontal and vertical zonation of AAP assemblages. Physicochemical parameters such as pH, inorganic nitrogen compounds, photosynthetically active radiation, total organic carbon and to a lesser extent particulate organic nitrogen and phosphorus, and biogenic activities (e.g. bacterial production, cell densities), acted in synergy to explain the population changes with depth. About half of the pufM sequences were <94% identical to known sequences. The AAP populations were predominantly (~80%) composed of Gammaproteobacteria, unlike most previously explored marine systems. Our results suggest that genetically distinct ecotypes inhabiting different niches may exist in natural AAP populations of the Mediterranean Sea whose genetic diversity is typical of oligotrophic environments. PMID:21039650

  3. Isolation and molecular characterization of antibiotic-resistant lactic acid bacteria from poultry and swine meat products.

    PubMed

    Aquilanti, Lucia; Garofalo, Cristiana; Osimani, Andrea; Silvestri, Gloria; Vignaroli, Carla; Clementi, Francesca

    2007-03-01

    The transfer via the food chain from animals to humans of microbes that are resistant to antimicrobial agents is of increasing concern. To determine the contributions of nonpathogenic microflora to the occurrence and spread of antibiotic resistance (AR) genes in the food chain, 123 lactic acid bacteria were isolated from 29 samples of raw and processed pork and chicken meat products that had previously tested positive for one or more AR genes that encode clinically relevant ARs: tet(M), tet(O), tet(K), erm(A), erm(B), erm(C), aac (6')-Ie aph (2")-Ia, mecA, and blaZ. All of the isolates were initially tested for their AR gene profiles by PCR. The 59 isolates carrying a tet, erm, or blaZ gene were taken through molecular identification, analyzed by determination of the MIC, and subjected to genetic fingerprinting. Lactococcus garvieae was the predominant species (28 isolates), followed by Lactobacillus plantarum (11 isolates) and L. salivarius (6 isolates), whereas Lactococcus lactis subsp. lactis, Lactobacillus johnsonii, L. reuteri, L. crispatus, and L. brevis were identified at lower frequencies. The tet(M) and erm(B) genes were the most frequently detected. Assessment of multiple resistances in 18 tet positive (tet+) isolates revealed that tet(M) plus erm(B) and tet(K) plus erm(B) were the most frequent AR gene patterns. Partial sequencing of the tet(M) open reading frame of three selected strains showed high sequence similarities (> 99%) with tet(M) genes previously found in human pathogens (Listeria monocytogenes and Neisseria meningitidis). Southern hybridization with plasmid profiles revealed these strains contained tet(M)-carrying plasmids. PMID:17388042

  4. Screening of antibacterial activity of lactic acid bacteria against different pathogens found in vacuum-packaged meat products.

    PubMed

    Awaisheh, Saddam S; Ibrahim, Salam A

    2009-11-01

    The objective of this work was to screen the antibacterial activity of lactic acid bacteria (LAB) isolated from different sources against different pathogens found in ready-to-eat vacuum-packaged meat products (RTE-VPMP). LAB were isolated from human, RTE-VPMP, fermented vegetables, and dairy samples. These isolates were assessed for their antibacterial activity against Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes, and Staphylococcus aureus using spot on lawn technique. Six LAB isolates-three from a human source, two from a RTE-VPMP source, and one from a fermented vegetable source-were found to be effective against all pathogenic strains. Antibacterial activities of cell-free neutral supernatant broths of these isolates were assessed against the different pathogenic strains to confirm bacteriocin production. All six isolates were effective against all pathogenic strains. LAB isolates from the human source had the highest antibacterial activity and were significantly more effective than other LAB isolates, with the inhibition zone ranging from 14 to 22 mm. Inhibition zones of RTE-VPMP LAB isolates were lower than those of human origin (inhibition zone range, 11-17 mm). The lowest activities were for the fermented vegetable isolate, for which inhibition zones ranged from 11 to 15 mm. The three isolates of human origin were identified as L. acidophilus, L. casei, and L. reuteri; the two isolates from RTE-VPMP source were both L. sake; and the one isolate of fermented vegetable origin was L. plantarum. Our results showed that nonmeat product-sourced LAB were effective against several foodborne pathogens, which suggests that they could be used as natural biopreservatives in many RTE-VPMP produced in Jordan. PMID:19694551

  5. Taxonomic and molecular characterization of lactic acid bacteria and yeasts in nunu, a Ghanaian fermented milk product.

    PubMed

    Akabanda, Fortune; Owusu-Kwarteng, James; Tano-Debrah, Kwaku; Glover, Richard L K; Nielsen, Dennis S; Jespersen, Lene

    2013-06-01

    Produced from raw unpasteurized milk, nunu is a spontaneously fermented yoghurt-like product made in Ghana and other parts of West Africa. Despite the importance of nunu in the diet of many Africans, there is currently only limited information available on the microorganisms associated with nunu processing. With the aim of obtaining a deeper understanding of the process and as a first step towards developing starter cultures with desired technological properties for nunu production, a microbiological characterization of nunu processing in three different towns in the Upper East region of Ghana, namely Bolgatanga, Paga and Navrongo, was carried out. Lactic acid bacteria (LAB) and yeasts associated with nunu processing were isolated and identified using a combination of pheno- and genotypic methods including morphological and carbohydrate fermentation tests, (GTG)5-based rep-PCR, multiplex PCR, and 16S and 26S rRNA gene sequencing. The LAB counts during nunu processing increased from 4.5 ± 0.4 log cfu/ml at 0 h to 8.7 ± 1.8 log cfu/ml at 24 h of fermentation while yeasts counts increased from 2.8 ± 1.2 log cfu/ml at 0 h to 5.8 ± 0.5 log cfu/ml by the end of fermentation. Lactobacillus fermentum was the dominant LAB throughout the fermentations with Lactobacillus plantarum and Leuconostoc mesenteroides playing prominent roles during the first 6-8 h of fermentation as well. Less frequently isolated LAB included Lactobacillus helveticus, Enterococcus faecium, Enterococcus italicus, Weissella confusa and a putatively novel Lactococcus spp. The yeasts involved were identified as Candida parapsilosis, Candida rugosa, Candida tropicalis, Galactomyces geotrichum, Pichia kudriavzevii and Saccharomyces cerevisiae with P. kudriavzevii and S. cerevisiae being the dominant yeast species. PMID:23541194

  6. Comparative study of the inhibitory effects of wine polyphenols on the growth of enological lactic acid bacteria.

    PubMed

    García-Ruiz, Almudena; Moreno-Arribas, M Victoria; Martín-Álvarez, Pedro J; Bartolomé, Begoña

    2011-02-28

    This paper reports a comparative study of the inhibitory potential of 18 phenolic compounds, including hydroxybenzoic acids and their derivatives, hydroxycinnamic acids, phenolic alcohols and other related compounds, stilbenes, flavan-3-ols and flavonols, on different lactic acid bacteria (LAB) strains of the species Oenococcus oeni, Lactobacillus hilgardii and Pediococcus pentosaceus isolated from wine. In general, flavonols and stilbenes showed the greatest inhibitory effects (lowest IC?? values) on the growth of the strains tested (0.160-0.854 for flavonols and 0.307-0.855 g/L for stilbenes). Hydroxycinnamic acids (IC?? > 0.470 g/L) and hydroxybenzoic acids and esters (IC?? >1 g/L) exhibited medium inhibitory effect, and phenolic alcohols (IC?? > 2 g/L) and flavanol-3-ols (negligible effect) showed the lowest effect on the growth of the LAB strains studied. In comparison to the antimicrobial additives used in winemaking, IC?? values of most phenolic compounds were higher than those of potassium metabisulphite for O. oeni strains (e.g., around 4-fold higher for quercetin than for potassium metabisulphite), but lower for L. hilgardii and P. pentosaceus strains (e.g., around 2-fold lower for quercetin). Lysozyme IC?? values were negligible for L. hilgardii and P. pentosaceus, and were higher than those corresponding to most of the phenolic compounds tested for O. oeni strains, indicating that lysozyme was less toxic for LAB than the phenolic compounds in wine. Scanning electron microscopy confirmed damage of the cell membrane integrity as a consequence of the incubation with antimicrobial agents. These results contribute to the understanding of the inhibitory action of wine phenolics on the progress of malolactic fermentation, and also to the development of new alternatives to the use of sulphites in enology. PMID:21295882

  7. Selection of functional lactic acid bacteria as starter cultures for the fermentation of Korean leek (Allium tuberosum Rottler ex Sprengel.).

    PubMed

    Yang, Jaesik; Ji, Yosep; Park, Hyunjoon; Lee, Jieun; Park, Soyoung; Yeo, Soyoung; Shin, Hyunkil; Holzapfel, Wilhelm H

    2014-11-17

    The purpose of this research was to find safe and suitable starter cultures for the fermentation of Korean leek (Allium tuberosum Rottler), also known as garlic chives or Oriental garlic. This traditional herb has several functional properties and a strong flavour; its leaves are used as food material. Eighteen strains of lactic acid bacteria (LAB) were isolated from well-fermented leek kimchi. Controlled fermentation of the leek leaves was conducted with 2 strains (Weissella confusa LK4 and Lactobacillus plantarum LK8), selected as potential starter cultures on the basis of their safety properties, and on the pH, total titratable acidity (TTA), and viable cell numbers [colony forming units (CFUml(-1))] achieved during the fermentation. Microbial dynamics was also followed during fermentation by using PCR-DGGE (Denaturing Gradient Gel Electrophoresis) on DNA level. To analyse bioactive compounds such as thiols and allicin (diallyl thiosulfinates), the total flavonoid and polyphenolic contents were determined by colorimetric methods. Functional properties were assessed on the basis of anti-oxidative capacities by determining the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging effect, and ferric reducing antioxidant power (FRAP). W. confusa LK4 rapidly increased during the first stage of leek fermentation, and was mainly responsible for accelerated fermentation during the early period in contrast to L. plantarum LK8, a stronger acid producer during the later stages of fermentation. After 48 h fermentation, leeks fermented with W. confusa LK4 showed the highest radical scavenging effects and reducing ability. The detectable amount of allicin of fermented leeks decreased relative to the change in pH, whereas the concentration of thiols significantly increased. Total flavonoid and poly-phenolic contents changed during fermentation and showed correlation with anti-oxidant effects. We therefore suggest the suitability of W. confusa LK4 as a potential starter culture for fermentation of leeks. PMID:25279760

  8. Lipid composition and vertical distribution of bacteria in aerobic sediments of the Venezuela Basin

    NASA Astrophysics Data System (ADS)

    Harvey, H. Rodger; Richardson, Michael D.; Patton, John S.

    1984-04-01

    Box cores of surface (0 to 30-cm) sediments from carbonate, hemipelagic, and turbidite sediment types of the deep (3493 to 5039-m) Venezuelan Basin were analyzed to investigate the relationship between the vertical distribution of bacteria, lipids, lipid phosphate, and grain size. The polar lipid fraction was isolated chromatographically and quantified by flame-ionization detection using the Iatroscan TH-10 analyzer. Total bacterial abundance was measured by epifluorescence microscopy in sediments (0 to 20-cm) from the carbonate and turbidite sediments. In all three sediment types investigated, both total and polar lipid concentrations decreased with increasing depth in the sediment. The highest total and polar lipid concentrations were at the sediment-water interface (0 to 2-cm) of hemipelagic sediments (62.0 and 25.7 ?g g -1 dry sediment, respectively) followed by the carbonate and turbidite sediments. A similar decline in lipid phosphate was also observed. Bacterial abundance was > 5 × 10 8 bacteria (per gram dry sediment) at the sediment surface in both sediments examined and over 1 × 10 7 bacteria 20 cm below the sediment-water interface. Polar lipid and lipid phosphate concentrations did not appear to correlate with estimates of bacterial biomass, even in regions where bacteria were apparently the only organisms present.

  9. Selecting lactic acid bacteria for their safety and functionality by use of a mouse colitis model.

    PubMed

    Daniel, Catherine; Poiret, Sabine; Goudercourt, Denise; Dennin, Veronique; Leyer, Gregory; Pot, Bruno

    2006-09-01

    Studies showed that specific probiotics might provide therapeutic benefits in inflammatory bowel disease. However, a rigorous screening of new probiotics is needed to study possible adverse interactions with the host, particularly when intended for administration to individuals with certain health risks. In this context, the objective of this study was to investigate the role of three lactobacilli (LAB) on intestinal inflammation and bacterial translocation using variations of the mouse model of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced acute colitis. We first compared the in vitro ability of LAB to survive gastrointestinal tract (GIT) conditions and their ability to persist in the GIT of mice following daily oral administration. As a control, we included a nonprobiotic Lactobacillus paracasei strain, previously isolated from an endocarditis patient. Feeding high doses of LAB strains to healthy and to TNBS-treated mice did not induce any detrimental effect or abnormal translocation of the bacteria. Oral administration of Lactobacillus salivarius Ls-33 had a significant preventive effect on colitis in mice, while Lactobacillus plantarum Lp-115 and Lactobacillus acidophilus NCFM did not. None of the three selected LAB strains translocated to extraintestinal organs of TNBS-treated mice. In contrast, L. paracasei exacerbated colitis under severe inflammatory conditions and translocated to extraintestinal organs. This study showed that evaluations of the safety and functionality of new probiotics are recommended. We conclude that not all lactobacilli have similar effects on intestinal inflammation and that selected probiotics such as L. salivarius Ls-33 may be considered in the prevention or treatment of intestinal inflammation. PMID:16957197

  10. Prevalence of antibiotic resistance in lactic acid bacteria isolated from the faeces of broiler chicken in Malaysia

    PubMed Central

    2014-01-01

    Background Probiotics are commonly used as feed additive to substitute antibiotic as growth promoter in animal farming. Probiotic consists of lactic acid bacteria (LAB), which enhance the growth and health of the animal. Probiotic also have higher possibility to become pathogenic bacteria that may carry antibiotic resistant gene that can be transmitted to other LAB species. The aim of this study was to identify the LAB species in the faeces of broiler chicken and to determine the prevalence of antibiotic resistant in LAB of broiler chicken. Methods Sixty faeces samples were collected from wet markets located in Klang Valley of Malaysia for the isolation of LAB using de-Mann Rogosa Sharpe medium. Thirteen species of LAB were obtained in this study and the identification of LAB was performed by using API test kit on the basis of carbohydrate fermentation profile. Antibiotic susceptibility assay was then carried out to determine the prevalence of LAB antibiotic resistance. Results Lactococcus lactis subsp lactis was found in nine out of sixty faecal samples. Lactobacillus paracasei was the second common LAB species isolated from chicken faecal. No significant difference (P > 0.05) was found between the occurrence of Lactobacillus brevis, Lactobacillus curvatus, Lactobacillus plantarum, Leuconostoc lactis mesenteroides subsp mesenteroides/dectranium and Pediococcus pentosaceus isolated from 5 different locations. Most of the isolated LAB was resistant to antibiotic and high variability of the antibiotic resistance was observed among the LAB against 15 types of antibiotics. Penicillin, amoxicillin, chloramphenicol, and ampicillin had significant higher (P< 0.05) inhibitory zone than nalidixic acid, gentamycin, sulphamethoxazole, kanamycin, and streptomycin. Conclusions Many species of LAB were isolated from the faecal samples of broiler chicken that resistance to the common antibiotics used in the farm. The development of resistant against antibiotics in LAB can be attributed to the long term exposure of antibiotic as growth promoter and therapeutic agents. Thus, it is essential to advise farmer the safety measure of antibiotic application in animal farming. Additionally, the supplementation of probiotic in animal feeding also needs more attention and close monitoring. PMID:24447766

  11. In vitro study of beneficial properties and safety of lactic acid bacteria isolated from Portuguese fermented meat products.

    PubMed

    Todorov, S D; Franco, B D G M; Wiid, I J

    2014-09-01

    Many lactic acid bacteria produce bacteriocins with a rather broad spectrum of inhibition, which could offer potential applications in food preservation. Bacteriocin production by starter cultures may bring advantage to these strains in competitive interactions with pathogenic bacteria from the food matrix. The objective of this study was to determine the safety of beneficial strains (Lactobacillus plantarum ST202Ch and ST216Ch, Enterococcus faecium ST211Ch, and Lactobacillus sakei ST22Ch, ST153Ch and ST154Ch) previously isolated from fermented meat products and characterised as bacteriocin producers. Auto-aggregation was strain-specific, and values of 28.97, 27.86 and 28.56% were recorded for L. sakei ST22Ch, ST153Ch and ST154Ch, respectively, 16.95 and 14.58% for L. plantarum ST202Ch and ST216Ch, respectively, and 12.77% for E. faecium ST211Ch. Various degrees of co-aggregation between 28.85 and 44.76% for Listeria monocytogenes 211 and 409, and between 23.60 to 34.96% for E. faecium ATCC 19443 were observed. According to the results of the diffusion method, the studied strains demonstrated susceptibility to penicillin G, ampicillin, amoxicillin, amoxicillin/clavulonic acid, imipenem, linezolid, and tetracycline. In addition, the susceptibility of the six strains to various non-antibiotic commercial drugs was examined. Production of ?-galactosidase by L. sakei ST22Ch, ST153Ch and ST154Ch, L. plantarum ST202Ch and ST216Ch, and E. faecium ST211Ch was confirmed by employing sterile filter paper discs impregnated with o-nitrophenyl-?-D-galactopyranose. A statistically significant (P<0.001) inhibition of Mycobacterium tuberculosis growth by bacteriocins produced by L. plantarum ST202Ch (38.3%) and ST216Ch (48.6%), L. sakei ST153Ch (16.2%) and ST154Ch (16.1%), and E. faecium ST211Ch (21.7%) was observed. As determined by the polymerase chain reaction, the tested strains showed a low virulence gene profile. PMID:24463204

  12. Aerobic degradation of a mixture of azo dyes in a packed bed reactor having bacteria-coated laterite pebbles.

    PubMed

    Senan, Resmi C; Shaffiqu, T S; Roy, J Jegan; Abraham, T Emilia

    2003-01-01

    A microbial consortium capable of aerobic degradation of a mixture of azo dyes consisting of two isolated strains (RRL,TVM) and one known strain of Pseudomonas putida (MTCC 1194) was immobilized on laterite stones. The amount of bacterial biomass attached to the laterite stones was 8.64 g per 100 g of the stone on a dry weight basis. The packed bed reactor was filled with these stones and had a total capacity of 850 mL and a void volume of 210 mL. The feed consisted of an equal mixture of seven azo dyes both in water as well as in a simulated textile effluent, at a pH of 9.0 and a salinity of 900 mg/L. The dye concentrations of influent were 25, 50, and 100 microg/mL. The residence time was varied between 0.78 and 6.23 h. It was found that at the lowest residence time 23.55, 45.73, and 79.95 microg of dye was degraded per hour at an initial dye concentration of 25, 50, and 100 microg, respectively. The pH was reduced from 9.0 to 7.0. Simulated textile effluent containing 50 microg/mL dye was degraded by 61.7%. Analysis of degradation products by TLC and HPLC showed that the dye mixture was degraded to nontoxic smaller molecules. The bacteria-coated pebbles were stable, there was no washout even after 2 months, and the reactor was found to be suitable for the aerobic degradation of azo dyes. PMID:12675610

  13. Distribution and Persistence of Staphylococcus and Micrococcus Species and Other Aerobic Bacteria on Human Skin1

    PubMed Central

    Kloos, Wesley E.; Musselwhite, Margaret S.

    1975-01-01

    The distribution of Staphylococcus and Micrococcus species and associated coryneform bacteria, Acinetobacter, Klebsiella, Enterobacter, Bacillus, and Streptomyces on skin was determined during October 1971 from samples collected on persons living in North Carolina and New Jersey. Persistence of these organisms on skin was estimated in temporal studies conducted during the period from June 1971 to June 1972 on persons living in North Carolina. Staphylococci and coryneforms were the most predominant and persistent bacteria isolated from the nares and axillae. Staphylococci, coryneforms, micrococci, and Bacillus were the most predominant and persistent bacteria isolated from the head, legs, and arms. Acinetobacters were most frequently isolated during the warmer months of the years. Staphylococcus aureus and S. epidermidis were the most predominant and persistent staphylococci isolated from the nares, whereas S. epidermidis and S. hominis were the most predominant and persistent staphylococci isolated from the axillae, head, legs, and arms. S. capitis was often isolated from the head and arms and S. haemolyticus was often isolated from the head, legs, and arms. S. simulans, S. xylosus, S. cohnii, S. saprophyticus, S. warneri, and an unclassified coagulase-positive species were only occasionally isolated from skin. Micrococcus luteus was the most predominant and persistent Micrococcus isolated from skin and preferred regions of the head, legs, and arms. M. varians was the second most frequent Micrococcus isolated. M. lylae, M. sedentarius, M. roseus, M. kristinae, and M. nishinomiyaensis were only occasionally isolated from skin. M. lylae was most frequently isolated during the colder months of the years. PMID:810086

  14. Cloning and Heterologous Production of Hiracin JM79, a Sec-Dependent Bacteriocin Produced by Enterococcus hirae DCH5, in Lactic Acid Bacteria and Pichia pastoris

    Microsoft Academic Search

    Jorge Sanchez; Juan Borrero; Beatriz Gomez-Sala; Antonio Basanta; Carmen Herranz; Luis M. Cintas; Pablo E. Hernandez

    2008-01-01

    Hiracin JM79 (HirJM79), a Sec-dependent bacteriocin produced by Enterococcus hirae DCH5, was cloned and produced in Lactococcus lactis, Lactobacillus sakei, Enterococcus faecium, Enterococcus faecalis, and Pichia pastoris. For heterologous production of HirJM79 in lactic acid bacteria (LAB), the HirJM79 structural gene (hirJM79), with or without the HirJM79 immunity gene (hiriJM79), was cloned into the plasmid pMG36c under the control of

  15. Population Changes in Enteric Bacteria and Other Microorganisms During Aerobic Thermophilic Windrow Composting1

    PubMed Central

    Savage, Jacob; Chase, Theodore; Macmillan, James D.

    1973-01-01

    Composting of wastes from swine feeding operations was studied. The effects of the frequency of turning the wastes and addition of straw to improve the physical structure were studied to determine the most effective technique to rapidly increase the temperature and, consequently, destroy coliforms and Salmonella. Four different treatments were studied; the results showed that, with addition of 5% (wt/wt) straw and mechanical turning of the compost 20 times per week, the temperature reached 60 C within 3 days and enteric bacteria were destroyed within 14 days. Images PMID:4203338

  16. In vivo application and dynamics of lactic acid bacteria for the four-season production of Vastedda-like cheese.

    PubMed

    Gaglio, Raimondo; Scatassa, Maria Luisa; Cruciata, Margherita; Miraglia, Viviana; Corona, Onofrio; Di Gerlando, Rosalia; Portolano, Baldassare; Moschetti, Giancarlo; Settanni, Luca

    2014-05-01

    Twelve lactic acid bacteria (LAB), previously selected in vitro (Gaglio et al., 2014), were evaluated in situ for their potential to act as starter cultures for the continuous four-season production of Vastedda-like cheese, made with raw ewes' milk. The strains belonged to Lactobacillus delbrueckii, Lactococcus lactis subsp. cremoris, Leuconostoc mesenteroides subsp. mesenteroides and Streptococcus thermophilus. LAB were first inoculated in multiple-strain combinations on the basis of their optimal growth temperatures in three process conditions which differed for milk treatment and medium for strain development: process 1, growth of strains in the optimal synthetic media and pasteurised milk; process 2, growth of strains in whey based medium (WBM) and pasteurised milk; and process 3, growth of strains in WBM and raw milk. The strains that acidified the curds in short time, as shown by a pH drop, were all mesophilic and were then tested in a single inoculum through process 3. Randomly amplified polymorphic DNA (RAPD)-PCR analysis applied to the colonies isolated from the highest dilutions of samples confirmed the dominance of the added strains after curd acidification, stretching and storage. After 15days of refrigerated storage, the decrease in pH values showed an activity of the mesophilic strains at low temperatures, but only Lc. lactis subsp. cremoris PON153, Ln. mesenteroides subsp. mesenteroides PON259 and PON559 increased their number during the 15days at 7°C. A sensory evaluation indicated that the cheeses obtained by applying protocol 3 and by inoculation with lactococci are the most similar to the protected denomination of origin (PDO) cheese and received the best scores by the judges. Thus, the experimental cheeses obtained with raw milk and inoculated with single and multiple combinations of lactococci were subjected to the analysis of the volatile organic compounds (VOCs) carried out by a headspace solid phase microextraction (SPME) technique coupled with gas chromatography with mass spectrometric detection (GC/MS). The dominance of lactococci over thermophilic LAB of raw milk was verified during summer production and, based on the combination of VOC profiles and sensory evaluation of the final cheeses, the multi-strain Lactococcus culture resulted in the most suitable starter preparation for the full-year production of Vastedda-like cheese. PMID:24598514

  17. Diversity of aerobic anoxygenic phototrophic bacteria in paddy soil and their response to elevated atmospheric CO2

    PubMed Central

    Feng, Youzhi; Lin, Xiangui; Mao, Tingting; Zhu, Jianguo

    2011-01-01

    Summary Aerobic anoxygenic phototrophic bacteria (AAnPB) are recognized as an important group driving the global carbon cycling. However, the diversity of AAnPB in terrestrial environment remains largely unknown as well as their responses to the elevated atmospheric CO2. By using culture?independent techniques, the diversity of AAnPB in paddy soil and the changes in response to the rising atmospheric CO2 were investigated within China FACE (Free?air CO2 enrichment) platform. There was a phylogenetically diverse AAnPB community with large population size residing in paddy soil. The community structure of AAnPB in bulk and rhizospheric soils stayed almost identical, while the population size was higher in rhizospheric [2.0–2.5?×?108 copy number of pufM genes g?1 dry weight soil (d.w.s.)] than that in bulk (0.7–0.8?×?108?g?1?d.w.s.) soils. Elevated atmospheric CO2 appeared to significantly stimulate AAnPB abundance (up to 1.4–1.5?×?108?g?1?d.w.s.) and result in a higher AAnPB percentage in total bacterial community (from 0.5% up to 1.5%) in bulk soil, whereas no significant effect was observed in rhizospheric soil. Our results would extend the functional ecotypes of AAnPB and indicate that environmental changes associated with the rising atmospheric CO2 might affect AAnPB community in paddy soil. PMID:21255374

  18. New aerobic ammonium-dependent obligately oxalotrophic bacteria: description of Ammoniphilus oxalaticus gen. nov., sp. nov. and Ammoniphilus oxalivorans gen. nov., sp. nov

    Microsoft Academic Search

    Gennadi M. Zaitsev; I. V. Tsitko; F. A. Rainey; Y. A. Trotsenko; J. S. Uotila; E. Stackebrandt; M. S. Salkinoja-Salonen

    1998-01-01

    The genus Ammoniphilus is proposed for aerobic endospore-forming Gram- variable rod-shaped bacteria, which are ammonium-dependent, obligately oxa lotrop h ic and haloa I ka I i to lerant, oxidase- and catal ase-pos i t ive, mesop h i I ic and motile by peritrichous flagella. Cell wall contained two electron-dense layers. The external layer consists of a chain of electron-dense

  19. METHANE OXIDATION (AEROBIC) Helmut Brgmann

    E-print Network

    Wehrli, Bernhard

    ; Madigan et al., 2003; Bowman, 2006). The process is performed by a specialized group of bacteria (qv) (Madigan et al., 2003). Thus, aerobic methane oxidation can be considered a special case of aerobic ADP ATP

  20. Sensory evaluation and consumer acceptance of naturally and lactic acid bacteria-fermented pastes of soybeans and soybean-maize blends.

    PubMed

    Ng'ong'ola-Manani, Tinna A; Mwangwela, Agnes M; Schüller, Reidar B; Ostlie, Hilde M; Wicklund, Trude

    2014-03-01

    Fermented pastes of soybeans and soybean-maize blends were evaluated to determine sensory properties driving consumer liking. Pastes composed of 100% soybeans, 90% soybeans and 10% maize, and 75% soybeans and 25% maize were naturally fermented (NFP), and lactic acid bacteria fermented (LFP). Lactic acid bacteria fermentation was achieved through backslopping using a fermented cereal gruel, thobwa. Ten trained panelists evaluated intensities of 34 descriptors, of which 27 were significantly different (P < 0.05). The LFP were strong in brown color, sourness, umami, roasted soybean-and maize-associated aromas, and sogginess while NFP had high intensities of yellow color, pH, raw soybean, and rancid odors, fried egg, and fermented aromas and softness. Although there was consumer (n = 150) heterogeneity in preference, external preference mapping showed that most consumers preferred NFP. Drivers of liking of NFP samples were softness, pH, fermented aroma, sweetness, fried egg aroma, fried egg-like appearance, raw soybean, and rancid odors. Optimization of the desirable properties of the pastes would increase utilization and acceptance of fermented soybeans. PMID:24804070

  1. Effect of spray-dried yogurt and lactic acid bacteria on the initiation and promotion stages of chemically induced skin carcinogenesis in mice.

    PubMed

    McCarthy, A C; La, E; Conti, C J; Locniskar, M F

    1997-01-01

    The effects of dietary spray-dried yogurt powder product (YPP) and two strains of lactic acid bacteria on the initiation and promotion stages of carcinogenesis were investigated using the 7,12-dimethylbenz[a]anthracene (DMBA)-12-O-tetradecanoylphorbol-13-acetate (TPA) mouse skin carcinogenesis model. In two independent studies, Sencar mice were fed a diet containing 86%, 43%, or 0% YPP or the 0% YPP diet supplemented with viable cultures of Lactobacillus acidophilus or bifidobacteria. Animals were initiated with a single topical application of DMBA (10 nmol). Promotion began three weeks later with twice weekly treatment of TPA (1 microgram/200 microliters acetone). During the initiation study (Study 1) the experimental diets were fed for four weeks before and one week after DMBA treatment. All mice were then switched to the AIN-76 diet. For the promotion study (Study 2) the experimental diets were begun one week after initiation and fed during the remainder of the study. Gross appearance of tumors was assessed weekly. No statistically significant differences in body weight or food disappearance were observed among the diet groups during the studies. For Studies 1 and 2, final histologically verified papilloma incidence and multiplicity and carcinoma incidence were not statistically different. These data suggest that different levels of YPP or lactic acid bacteria fed during the initiation or promotion stage of carcinogenesis do not significantly affect chemically induced skin tumor development. PMID:9101551

  2. Hexavalent chromium reduction by aerobic heterotrophic bacteria indigenous to chromite mine overburden

    PubMed Central

    Dey, Satarupa; Paul, A.K.

    2013-01-01

    Microbiological analysis of overburden samples collected from chromite mining areas of Orissa, India revealed that they are rich in microbial density as well as diversity and dominated by Gram-negative (58%) bacteria. The phenotypically distinguishable bacterial isolates (130) showed wide degree of tolerance to chromium (2–8 mM) when tested in peptone yeast extract glucose agar medium. Isolates (92) tolerating 2 mM chromium exhibited different degrees of Cr+6 reducing activity in chemically defined Vogel Bonner (VB) broth and complex KSC medium. Three potent isolates, two belonging to Arthrobacter spp. and one to Pseudomonas sp. were able to reduce more than 50 and 80% of 2 mM chromium in defined and complex media respectively. Along with Cr+6 (MIC 8.6–17.8 mM), the isolates showed tolerance to Ni+2, Fe+3, Cu+2 and Co+2 but were extremely sensitive to Hg+2 followed by Cd+2, Mn+2 and Zn+2. In addition, they were resistant to antibiotics like penicillin, methicillin, ampicillin, neomycin and polymyxin B. During growth under shake-flask conditions, Arthrobacter SUK 1201 and SUK 1205 showed 100% reduction of 2 mM Cr+6 in KSC medium with simultaneous formation of insoluble precipitates of chromium salts. Both the isolates were also equally capable of completely reducing the Cr+6 present in mine seepage when grown in mine seepage supplemented with VB concentrate. PMID:24159321

  3. Taxonomic Structure and Monitoring of the Dominant Population of Lactic Acid Bacteria during Wheat Flour Sourdough Type I Propagation Using Lactobacillus sanfranciscensis Starters?

    PubMed Central

    Siragusa, Sonya; Di Cagno, Raffaella; Ercolini, Danilo; Minervini, Fabio; Gobbetti, Marco; De Angelis, Maria

    2009-01-01

    The structure and stability of the dominant lactic acid bacterium population were assessed during wheat flour sourdough type I propagation by using singly nine strains of Lactobacillus sanfranciscensis. Under back-slopping propagation with wheat flour type 0 F114, cell numbers of presumptive lactic acid bacteria varied slightly between and within starters. As determined by randomly amplified polymorphic DNA-PCR and restriction endonuclease analysis-pulsed-field gel electrophoresis analyses, only three (LS8, LS14, and LS44) starters dominated throughout 10 days of propagation. The others progressively decreased to less than 3 log CFU g?1. Partial sequence analysis of the 16S rRNA and recA genes and PCR-denaturating gradient gel electrophoresis analysis using the rpoB gene allowed identification of Weissella confusa, Lactobacillus sanfranciscensis, Lactobacillus plantarum, Lactobacillus rossiae, Lactobacillus brevis, Lactococcus lactis subsp. lactis, Pediococcus pentosaceus, and Lactobacillus spp. as the dominant species of the raw wheat flour. At the end of propagation, one autochthonous strain of L. sanfranciscensis was found in all the sourdoughs. Except for L. brevis, strains of the above species were variously found in the mature sourdoughs. Persistent starters were found in association with other biotypes of L. sanfranciscensis and with W. confusa or L. plantarum. Sourdoughs were characterized for acidification, quotient of fermentation, free amino acids, and community-level catabolic profiles by USING Biolog 96-well Eco microplates. In particular, catabolic profiles of sourdoughs containing persistent starters behaved similarly and were clearly differentiated from the others. The three persistent starters were further used for the production of sourdoughs and propagated by using another wheat flour whose lactic acid bacterium population in part differed from the previous one. Also, in this case all three starter strains persisted during propagation. PMID:19088320

  4. Association of mutation patterns in GyrA and ParC genes with quinolone resistance levels in lactic acid bacteria.

    PubMed

    Li, Shaoying; Li, Zhen; Wei, Wan; Ma, Chunyan; Song, Xiaomin; Li, Shufen; He, Wenying; Tian, Jianjun; Huo, Xiaoyan

    2015-02-01

    The quinolone resistance of 19 lactic acid bacterial strains belonging to the genera Enterococcus and Lactobacillus isolated from the natural fermented koumiss and yoghurt were investigated. The objective of this study was to determine the quinolone resistance levels and to explore the association of the resistance with the mutation patterns in gyrA and parC genes, as is currently recommended by the Food and Agriculture Organization/World Health Organization Joint Expert Committee in Guidelines for Evaluation of Probiotics in Food for probiotic lactic acid bacteria drug resistance in 2001. The Oxford Cup method and double-tube dilution method were used to determine the quinolone resistance levels of the isolated strains. Generally, all of the 19 strains showed resistance towards norfloxacin and ciprofloxacin when the Oxford cup method was used, whereas the incidence was lower (to norfloxacin 89.5% and to ciprofloxacin 68.4%) when minimum inhibitory concentration breakpoints (CLSI M100-S23) were tested. Furthermore, gene sequencing was conducted on gyrA and parC of topoisomerase II of these isolated strains. The genetic basis for quinolone resistance may be closely related to mutations in gyrA genes as there were 10 mutation sites in amino-acid sequences encoded by gyrA genes in 10 quinolone resistance strains and 14 mutation sites in Enterococcus durans HZ28, whereas no typical mutations were detected in parC genes. PMID:25204345

  5. Three-dimensional structure of leucocin A in trifluoroethanol and dodecylphosphocholine micelles: spatial location of residues critical for biological activity in type IIa bacteriocins from lactic acid bacteria.

    PubMed

    Fregeau Gallagher, N L; Sailer, M; Niemczura, W P; Nakashima, T T; Stiles, M E; Vederas, J C

    1997-12-01

    The first three-dimensional structure of a type IIa bacteriocin from lactic acid bacteria is reported. Complete 1H resonance assignments of leucocin A, a 37 amino acid antimicrobial peptide isolated from the lactic acid bacterium Leuconostoc gelidum UAL187, were determined in 90% trifluoroethanol (TFE)-water and in aqueous dodecylphosphocholine (DPC) micelles (1:40 ratio of leucocin A:DPC) using two-dimensional NMR techniques (e.g., DQF-COSY, TOCSY, NOESY). Circular dichroism spectra, NMR chemical shift indices, amide hydrogen exchange rates, and long-range nuclear Overhauser effects indicate that leucocin A adopts a reasonably well defined structure in both TFE and DPC micelle environments but exists as a random coil in water or aqueous DMSO. Distance geometry and simulated annealing calculations were employed to generate structures for leucocin A in both lipophilic media. While some differences were noted between the structures calculated for the two different solvent systems, in both, the region encompassing residues 17-31 assumes an essentially identical amphiphilic alpha-helix conformation. A three-strand antiparallel beta-sheet domain (residues 2-16), anchored by the disulfide bridge, is also observed in both media. In TFE, these two regions have a more defined relationship relative to each other, while, in DPC micelles, the C-terminus is folded back onto the alpha-helix. The implications of these structural features with regard to the antimicrobial mechanism of action and target recognition are discussed. PMID:9398233

  6. Comparison of nitroethane, 2-nitro-1-propanol, lauric acid, Lauricidin® and the Hawaiian marine algae, Chaetoceros, for potential broad-spectrum control of anaerobically grown lactic acid bacteria.

    PubMed

    Božic, Aleksandar K; Anderson, Robin C; Ricke, Steven C; Crandall, Philip G; O'Bryan, Corliss A

    2012-01-01

    The gastrointestinal tract of bovines often contains bacteria that contribute to disorders of the rumen, and may also contain foodborne or opportunistic human pathogens as well as bacteria capable of causing mastitis in cows. Thus there is a need to develop broad-spectrum therapies that are effective while not leading to unacceptably long antibiotic withdrawal times. The effects of the CH(4)-inhibitors nitroethane (2 mg/mL), 2-nitro-1-propanol (2 mg/mL), lauric acid (5 mg/mL), the commercial product Lauricidin® (5 mg/mL), and a finely ground product of the Hawaiian marine algae, Chaetoceros (10 mg/mL), were compared in pure cultures of Streptococcus agalactia, Enterococcus faecium, Streptococcus bovis, and in a mixed lactic acid rumen bacterial culture. Lauricidin® and lauric acid exhibited the most bactericidal acidity against all bacteria. These results suggest potential animal health benefits from supplementing cattle diets with lauric acid or Lauricidin® to improve the health of the rumen and help prevent shedding of human pathogens. PMID:22428888

  7. 16S rRNA sequence determination for members of the genus Carnobacterium and related lactic acid bacteria and description of Vagococcus salmoninarum sp. nov.

    PubMed

    Wallbanks, S; Martinez-Murcia, A J; Fryer, J L; Phillips, B A; Collins, M D

    1990-07-01

    The phylogenetic interrelationships of members of the genus Carnobacterium and some atypical lactobacilli isolated from diseased salmonid fish were investigated by using reverse transcriptase sequencing of 16S rRNA. The four species Carnobacterium piscicola, Carnobacterium divergens, Carnobacterium gallinarum, and Carnobacterium mobile exhibited a high degree of sequence similarity with each other (ca. 96 to 98%) and formed a phylogenetically coherent group that was quite distinct from all other lactic acid bacteria. The sequence data clearly demonstrated that carnobacteria are phylogenetically closer to the genera Enterococcus and Vagococcus than to members of the genus Lactobacillus. The strains from fish were found to be phylogenetically related to the genus Vagococcus and represent a new species, Vagococcus salmoninarum. The type strain of Vagococcus salmoninarum is strain NCFB 2777. PMID:1697764

  8. Preparation of lactic acid bacteria-enclosing alginate beads in emulsion system: effect of preparation parameters on bead characteristics

    Microsoft Academic Search

    Takayuki Takei; Masahiro Yoshida; Yasuo Hatate; Kouichiro Shiomori; Shiro Kiyoyama

    2009-01-01

    The immobilization of plant growth-promoting bacteria in biodegradable polymeric supports is effective in providing them with\\u000a a suitable microenvironment for increased survival, compared to free bacteria, in agricultural land. In this study, we optimized\\u000a the preparation parameters for bacteria-enclosing calcium alginate gel beads with a view to large-scale production. An emulsion\\u000a system was used and the optimization was based on

  9. Hydrolysis of Sequenced ?-Casein Peptides Provides New Insight into Peptidase Activity from Thermophilic Lactic Acid Bacteria and Highlights Intrinsic Resistance of Phosphopeptides

    PubMed Central

    Deutsch, Stéphanie-Marie; Molle, Daniel; Gagnaire, Valérie; Piot, Michel; Atlan, Danièle; Lortal, Sylvie

    2000-01-01

    The peptidases of thermophilic lactic acid bacteria have a key role in the proteolysis of Swiss cheeses during warm room ripening. To compare their peptidase activities toward a dairy substrate, a tryptic/chymotryptic hydrolysate of purified ?-casein was used. Thirty-four peptides from 3 to 35 amino acids, including three phosphorylated peptides, constitute the ?-casein hydrolysate, as shown by tandem mass spectrometry. Cell extracts prepared from Lactobacillus helveticus ITG LH1, ITG LH77, and CNRZ 32, Lactobacillus delbrueckii subsp. lactis ITG LL14 and ITG LL51, L. delbrueckii subsp. bulgaricus CNRZ 397 and NCDO 1489, and Streptococcus thermophilus CNRZ 385, CIP 102303, and TA 060 were standardized in protein. The peptidase activities were assessed with the ?-casein hydrolysate as the substrate at pH 5.5 and 24°C (conditions of warm room ripening) by (i) free amino acid release, (ii) reverse-phase chromatography, and (iii) identification of undigested peptides by mass spectrometry. Regardless of strain, L. helveticus was the most efficient in hydrolyzing ?-casein peptides. Interestingly, cell extracts of S. thermophilus were not able to release a significant level of free proline from the ?-casein hydrolysate, which was consistent with the identification of numerous dipeptides containing proline. With the three lactic acid bacteria tested, the phosphorylated peptides remained undigested or weakly hydrolyzed indicating their high intrinsic resistance to peptidase activities. Finally, several sets of peptides differing by a single amino acid in a C-terminal position revealed the presence of at least one carboxypeptidase in the cell extracts of these species. PMID:11097915

  10. Use of unsupervised and supervised artificial neural networks for the identification of lactic acid bacteria on the basis of SDS-PAGE patterns of whole cell proteins.

    PubMed

    Piraino, P; Ricciardi, A; Salzano, G; Zotta, T; Parente, E

    2006-08-01

    Conventional multivariate statistical techniques (hierarchical cluster analysis, linear discriminant analysis) and unsupervised (Kohonen Self Organizing Map) and supervised (Bayesian network) artificial neural networks were compared for as tools for the classification and identification of 352 SDS-PAGE patterns of whole cell proteins of lactic acid bacteria belonging to 22 species of the genera Lactobacillus, Leuconostoc, Enterococcus, Lactococcus and Streptococcus including 47 reference strains. Electrophoretic data were pre-treated using the logistic weighting function described by Piraino et al. [Piraino, P., Ricciardi, A., Lanorte, M. T., Malkhazova, I., Parente, E., 2002. A new procedure for data reduction in electrophoretic fingerprints of whole-cell proteins. Biotechnol. Lett. 24, 1477-1482]. Hierarchical cluster analysis provided a satisfactory classification of the patterns but was unable to discriminate some species (Leuconostoc, Lb. sakei/Lb. curvatus, Lb. acidophilus/Lb. helveticus, Lb. plantarum/Lb. paraplantarum, Lc. lactis/Lc. raffinolactis). A 7x7 Kohonen self-organizing map (KSOM), trained with the patterns of the reference strains, provided a satisfactory classification of the patterns and was able to discriminate more species than hierarchical cluster analysis. The map was used in predictive mode to identify unknown strains and provided results which in 85.5% of cases matched the classification obtained by hierarchical cluster analysis. Two supervised tools, linear discriminant analysis and a 23:5:2 Bayesian network were proven to be highly effective in the discrimination of SDS-PAGE patterns of Lc. lactis from those of other species. We conclude that data reduction by logistic weighting coupled to traditional multivariate statistical analysis or artificial neural networks provide an effective tool for the classification and identification of lactic acid bacteria on the basis of SDS-PAGE patterns of whole cell proteins. PMID:16480784

  11. Effects of carbon dioxide on the fate of Listeria monocytogenes, of aerobic bacteria and on the development of spoilage in minimally processed fresh endive.

    PubMed

    Carlin, F; Nguyen-the, C; Abreu Da Silva, A; Cochet, C

    1996-09-01

    Minimally processed fresh broad-leaved endive (Cichorium endivia L.) were stored at 3 and 10 degrees C in modified atmospheres containing air, 10% CO2/10% O2, 30% CO2/10% O2, and 50% CO2/10% O2. The effects of these modified atmospheres on the fate of both aerobic bacteria and three strains of Listeria monocytogenes, was investigated. Increases in CO2 concentrations significantly reduced the growth of the aerobic microflora. The best preservation of the visual quality occurred on endive leaves stored in 10% CO2/10% O2, whereas leaves stored in 30% CO2/10% O2 and 50% CO2/10% O2, and to a lesser extent in air, showed extensive spoilage after storage. Listeria monocytogenes was slightly affected at 3 degrees C by the modified atmospheres, as compared to air. At 10 degrees C, results varied between replicate experiments, but L. monocytogenes generally grew better as the CO2 concentration was increased. The three test strains behaved in a similar way. In conclusion, among the modified atmospheres tested, a modified atmosphere containing 10% CO2/10% O2 resulted in improved visual quality of minimally processed fresh endive, without a marked effect on the growth of the aerobic microflora or of L. monocytogenes. PMID:8880336

  12. In vitro modulation of tumor necrosis factor ? production in THP-1 cells by lactic acid bacteria isolated from healthy human infants.

    PubMed

    Ladda, Boonyarut; Theparee, Talent; Chimchang, Juntana; Tanasupawat, Somboon; Taweechotipatr, Malai

    2015-06-01

    The human microbiota is a source of probiotics capable of modulating the host immune system. In this study, we collected fecal samples from 100 healthy infants and isolated lactic acid bacteria which were screened for immune modulating effects on tumor necrosis factor ? (TNF-?) production. Cell-free culture supernatants from 26 isolates were able to decrease TNF-? production in vitro and three of the isolates were selected as candidate probiotics (MSMC39-1, MSMC39-3, MSMC57-1). These isolates were identified using 16S ribosomal DNA sequencing as Lactobacillus paracasei, Lactobacillus casei, and Weissella confusa respectively. All three isolates were acid tolerant and bile tolerant to pH 3.0 and 4% bile respectively. Preparations of cell-free culture supernatants were processed and tested, and revealed that cell-free culture supernatants of isolates L. paracasei MSMC39-1, L. casei MSMC39-3, and W. confusa MSMC57-1 decreased the production of TNF-? significantly and were heat resistant. Only L. paracasei MSMC39-1 supernatant was proteinase-K sensitive. The effects of viable bacteria, heat-killed bacteria, and sonicated bacteria were compared. The heat-killed preparations of isolate W. confusa MSMC57-1 decreased the production of TNF-?. Sonicated cell preparations did not significantly alter TNF-? production. For isolates L. paracasei MSMC39-1 and L. casei MSMC39-3, this suggests that a substance in the cell-free culture supernatant may be responsible for in vitro cytokine modulation. PMID:25759008

  13. Microbial Lactic Acid Production from Renewable Resources

    Microsoft Academic Search

    Yebo Li; Fengjie Cui

    \\u000a Lactic acid is widely used in the food, chemical, textile, and pharmaceutical industries. New applications of lactic acid\\u000a for the manufacture of biodegradable polymers have increased the demand for it. Lactic acid can be produced from cheese whey\\u000a and starchy and lignocellulosic biomass via microbial fermentation with lactic acid bacteria (LAB) or fungi. Pure sugar and\\u000a cheese whey can be

  14. Investigation of aerobic and anaerobic ammonium-oxidising bacteria presence in a small full-scale wastewater treatment system comprised by UASB reactor and three polishing ponds.

    PubMed

    Araujo, J C; Correa, M M S; Silva, E C; Campos, A P; Godinho, V M; Von Sperling, M; Chernicharo, C A L

    2010-01-01

    This work applied PCR amplification method and Fluorescence in situ hybridisation (FISH) with primers and probes specific for the anammox organisms and aerobic ammonia-oxidising beta-Proteobacteria in order to detect these groups in different samples from a wastewater treatment system comprised by UASB reactor and three polishing (maturation) ponds in series. Seven primer pairs were used in order to detect Anammox bacteria. Positive results were obtained with three of them, suggesting that Anammox could be present in polishing pond sediments. However, Anammox bacteria were not detected by FISH, indicating that they were not present in sediment samples, or they could be present but below FISH detection limit. Aerobic ammonia- and nitrite-oxidising bacteria were verified in water column samples through Most Probable Number (MPN) analysis, but they were not detected in sediment samples by FISH. Ammonia removal efficiencies occurred systematically along the ponds (24, 32, and 34% for polishing pond 1, 2, and 3, respectively) but the major reaction responsible for this removal is still unclear. Some nitrification might have occurred in water samples because some nitrifying bacteria were present. Also Anammox reaction might have occurred because Anammox genes were detected in the sediments, but probably this reaction was too low to be noticed. It is important also to consider that some of the ammonia removal observed might be related to NH(3) stripping, associated with the pH increase resulting from the intensive photosynthetic activity in the ponds (mechanism under investigation). Therefore, it can be concluded that more than one mechanism (or reaction) might be involved in the ammonia removal in the polishing ponds investigated in this study. PMID:20150711

  15. Phenotypic identification and technological attributes of native lactic acid bacteria present in fermented bamboo shoot products from North-East India.

    PubMed

    Sonar, Nitin R; Halami, Prakash M

    2014-12-01

    Fermented bamboo shoots such as Soibum, Soidon, Eup, Hirring, Hecche and Ekung etc. are non-salted acidic products obtained by natural fermentation predominantly with lactic acid bacteria (LAB). In this study, we have characterized 11-representative LAB that includes, Lactobacillus sp. (n?=?2), Lactobacillus plantarum (n?=?3), and one each of Lactobacillus fermentum, Lactococcus sp., Lactobacillus brevis, Lactobacillus curvatus, Leuconostoc sp. and Lactobacillus xylosus. Subsequently, these cultures were studied for their technological and functional properties. Different isolates exhibited variation in their activities. L. brevis showed maximum phytic acid degradation ability (19.33 U ml (-1) ). L. xylosus had highest protease activity (64.2 nmol/ml) and also exhibited lipolytic activity. In addition, degree of cell hydrophobicity among these cultures ranged between 12.5 and 93.48 % with L. plantarum (SM2) showing highest degree of activity. Lactobacillus plantarum was the most common species found in the product studied. Results indicated that most of the LABs showed putative probiotic as well as antagonistic properties against the selected pathogenic bacteria. Characteristic aroma, flavour and texture in the fermented bamboo shoot products could be attributed to presence of these new LAB isolates. PMID:25477695

  16. Impact of Cell-free Supernatant of Lactic Acid Bacteria on Putrescine and Other Polyamine Formation by Foodborne Pathogens in Ornithine Decarboxylase Broth.

    PubMed

    Ozogul, Fatih; Tabanelli, Giulia; Toy, Nurten; Gardini, Fausto

    2015-06-24

    Conversion of ornithine to putrescine by Salmonella Paratyphi A, Listeria monocytogenes, Staphylococcus aureus, and Escherichia coli was investigated in ornithine decarboxylase broth (ODB) using cell-free supernatants (CFSs) obtained from Leuconostoc mesenterodies subsp. cremoris, Pediococcus acidilactici, Lactococcus lactis subsp. lactis, Streptococcus thermophilus. Two groups of cell-free supernatants (25 or 50%) and control (only ODB) were prepared to investigate putrescine (PUT) and other polyamine formation by foodborne pathogens (FBPs). Significant differences (p < 0.05) were observed among the species for each amine. All of the CFSs reduced the formation of PUT by ?65%. The production of cadaverine (CAD) was scarcely affected by the presence of CFSs, with the exception of the samples inoculated with L. monocytogenes. The variation in polyamine was found with respect to the control samples. Spermidine (SPD) was produced in lower amount in many samples, especially in Gram-negative FBPs, whereas spermine (SPN) increased drastically in the major part of the samples concerning the control. Histamine (HIS) was characterized by a marked concentration decrease in all of the samples, and tyramine (TYR) was accumulated in very low concentrations in the controls. Therefore, the ability of bacteria to produce certain biogenic amines such as HIS, TYR, PUT, and CAD has been studied to assess their risk and prevent their formation in food products. The results obtained from this study concluded that the lactic acid bacteria (LAB) strains with non-decarboxylase activity are capable of avoiding or limiting biogenic amine formation by FBP. PMID:26043863

  17. Short communication: Latin-style fresh cheese enhances lactic acid bacteria survival but not Listeria monocytogenes resistance under in vitro simulated gastrointestinal conditions.

    PubMed

    Silva, C C G; Domingos-Lopes, M F P; Magalhães, V A F; Freitas, D A S R; Coelho, M C; Rosa, H J D; Dapkevicius, M L N E

    2015-07-01

    Different studies in humans have provided evidence about the health benefits of probiotics. However, most probiotic strains do not maintain good viability in the harsh conditions of the gastrointestinal tract (GIT). In the present study, Latin-style fresh cheese produced with potential probiotic bacteria was tested to evaluate this cheese type as a food carrier for the delivery of viable microorganisms after exposure to simulated GIT conditions. The resistance of 28 lactic acid bacteria (LAB) strains and Listeria monocytogenes upon exposure to acidic conditions (pH 2.5) and bile and pancreatic enzymes (0.3% of bile salts and 0.1% of pancreatin) was evaluated in vitro. When compared with fresh cultures, fresh cheese greatly improved LAB survival to simulated GIT conditions, as no loss of viability was observed in either acidic conditions (pH 2.5) or bile salts and pancreatin environment over a 3-h period. In opposition, L. monocytogenes did not survive after 1h under acidic conditions. These data demonstrated that Latin-style fresh cheese could play an important role in probiotic protection against gastrointestinal juices, enhancing delivery within the gut and thereby maximizing potential health benefits of LAB. PMID:25912867

  18. Nucleotide sequences of genes coding for photosynthetic reaction centers and light-harvesting proteins of Acidiphilium rubrum and related aerobic acidophilic bacteria.

    PubMed

    Nagashima, K V; Matsuura, K; Wakao, N; Hiraishi, A; Shimada, K

    1997-11-01

    The nucleotide sequences of the puf operons of the Zn-bacteriochlorophyll a (Zn-BChl a)-containing photosynthetic aerobic bacteria, Acidiphilium rubrum and Acidiphilium angustum, were determined. The nucleotide sequences of the pufL and -M of Acidiphilium cryptum, Acidiphilium multivorum, and Acidiphilium organovorum were also determined. The puf operons of A. rubrum and A. angustum contained pufB, -A, -L, -M, and -C as seen in other purple bacteria with an unknown gene directly upstream of pufB. Comparing the deduced amino acid sequences of the puf genes of the Acidiphilium species with those of other purple bacteria showed that His L168, which is highly conserved in other bacteria, is replaced by a glutamic acid in the Acidiphilium species. The three-dimensional structures of the reaction centers of Blastochloris (Rhodopseudomonas) viridis and Rhodobacter sphaeroides suggest that this residue locates closely to a special pair of bacteriochlorophylls and may be involved in the stabilization and function of "Zn-BChl a". The relative content of charged amino acid residues in the L and M subunit is a little lower in A. rubrum (10% of total) than in B. viridis (12%), and the tendency is more pronounced in the cytochrome subunit: 12.5% in A. rubrum and 18.8% in B. viridis. PMID:9435141

  19. Microbial diversity of aerobic heterotrophic bacteria inside the foregut of two tyrphophilous water beetle species (Coleoptera: Dytiscidae)

    Microsoft Academic Search

    O. Schaaf; K. Dettner

    1997-01-01

    Using nutrient-rich and poor media 30 eutrophic or facultatively oligotrophic bacterial strains were isolated in a microbiological study of the aerobic, heterotrophic bacterial flora inside the foregut of the water beetle species Agabus affinis (Payk.) and Hydroporus melanarius Strm., 41 strains were isolated from the aquatic habitat of both beetles. A comparison is made between bacterial communities inside the beetles'

  20. Qualitative detection of class IIa bacteriocinogenic lactic acid bacteria from traditional Chinese fermented food using a YGNGV-motif-based assay.

    PubMed

    Liu, Wenli; Zhang, Lanwei; Yi, Huaxi; Shi, John; Xue, Chaohui; Li, Hongbo; Jiao, Yuehua; Shigwedha, Nditange; Du, Ming; Han, Xue

    2014-05-01

    In the present study, a YGNGV-motif-based assay was developed and applied. Given that there is an increasing demand for natural preservatives, we set out to obtain lactic acid bacteria (LAB) that produce bacteriocins against Gram-positive and Gram-negative bacteria. We here isolated 123 LAB strains from 5 types of traditional Chinese fermented food and screened them for the production of bacteriocins using the agar well diffusion assay (AWDA). Then, to acquire LAB producing class IIa bacteriocins, we used a YGNGV-motif-based assay that was based on 14 degenerate primers matching all class IIa bacteriocin-encoding genes currently deposited in NCBI. Eight of the LAB strains identified by AWDA could inhibit Gram-positive and Gram-negative bacteria; 5 of these were YGNGV-amplicon positive. Among these 5 isolates, amplicons from 2 strains (Y31 and Y33) matched class IIa bacteriocin genes. Strain Y31 demonstrated the highest inhibitory activity and the best match to a class IIa bacteriocin gene in NCBI, and was identified as Enterococcus faecium. The bacteriocin from Enterococcus avium Y33 was 100% identical to enterocin P. Both of these strains produced bacteriocins with strong antimicrobial activity against Listeria monocytogenes, Escherichia coli, and Bacillus subtilis, hence these bacteriocins hold promise as potential bio-preservatives in the food industry. These findings also indicated that the YGNGV-motif-based assay used in this study could identify novel class IIa bacteriocinogenic LAB, rapidly and specifically, saving time and labour by by-passing multiple separation and purification steps. PMID:24681304

  1. Aerobic conditions increase isoprenoid biosynthesis pathway gene expression levels for carotenoid production in Enterococcus gilvus.

    PubMed

    Hagi, Tatsuro; Kobayashi, Miho; Nomura, Masaru

    2015-06-01

    Some lactic acid bacteria that harbour carotenoid biosynthesis genes (crtNM) can produce carotenoids. Although aerobic conditions can increase carotenoid production and crtNM expression levels, their effects on the pathways that synthesize carotenoid precursors such as mevalonate and isoprene are not completely understood. In this study, we investigated whether aerobic conditions affected gene expression levels involved in the isoprenoid biosynthesis pathway that includes the mevalonate and isoprene biosynthesis pathways in Enterococcus gilvus using real-time quantitative reverse transcription PCR. NADH oxidase (nox) and superoxide dismutase (sod) gene expression levels were investigated as controls for aerobic conditions. The expression levels of nox and sod under aerobic conditions were 7.2- and 8.0-fold higher, respectively, than those under anaerobic conditions. Aerobic conditions concomitantly increased the expression levels of crtNM carotenoid biosynthesis genes. HMG-CoA synthase gene expression levels in the mevalonate pathway were only slightly increased under aerobic conditions, whereas the expression levels of HMG-CoA reductase and five other genes in the isoprene biosynthesis pathways were 1.2-2.3-fold higher than those under anaerobic conditions. These results demonstrated that aerobic conditions could increase the expression levels of genes involved in the isoprenoid biosynthesis pathway via mevalonate in E. gilvus. PMID:25962871

  2. Novel ferulate esterase from Gram-positive lactic acid bacteria and analyses of the recombinant enzyme produced in E. coli

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using a plate containing ethyl ferulate as sole carbon source, various bacteria cultures were screened for ferulate esterase (FAE). Among a dozen of species showing positive FAE, one Lactobacillus fermentum strain NRRL 1932 demonstrated the strongest activity. Using a published sequence of ferulate ...

  3. Synthesis of 2-methoxy benzoquinone and 2,6-dimethoxybenzoquinone by selected lactic acid bacteria during sourdough fermentation of wheat germ

    PubMed Central

    2013-01-01

    Background In the last decade, several studies described the promising cytotoxic activity of fermented wheat germ towards cancer cell lines and during in vivo clinical trials. Recent data suggested that the antiproliferative, antimetastatic and immunological effects of this preparation are mainly attributed to quinones. This study aimed at exploiting the potential of sourdough lactic acid bacteria fermentation to release 2-methoxy benzoquinone, and 2,6-dimethoxybenzoquinone, which are naturally present in wheat germ as glycosylated and non-physiologically active form. Results Preliminarily, forty strains of lactic acid bacteria, previously isolated from wheat germ, were in vitro screened based on ?-glucosidase activity. Lactobacillus plantarum LB1 and Lactobacillus rossiae LB5 were selected based on the highest enzyme activity and on technology features. These strains were used in combination to ferment wheat germ. Raw wheat germ, without bacterial inoculum, was subjected to the same incubation and used as the control. The sourdough fermented wheat germ was characterized based on microbiological, physico-chemical and biochemical features. During incubation, the release of the non-glycosylated and physiologically active 2-methoxy benzoquinone, and 2,6-dimethoxybenzoquinone was almost completed during 24 h. Compared to the control, the concentration of the above bioactive compounds increased almost 4 and 6-folds. Both raw wheat germ (control) and sourdough fermented wheat germ were ex vivo assayed for the anti-proliferative activity towards various cell lines of germ cell tumor, colon carcinoma and ovarian carcinoma. While no effect was found for the raw wheat germ, the sourdough fermented preparation markedly and variously affected the human tumor cell lines. The values of IC50 ranged from 0.105?±?0.005 to 0.556?±?0.071 mg/ml, with a median value of IC50 of 0.302 mg/ml. Conclusions These results are comparable to those found for other well-known pharmaceutical preparations, and may disclose the use of the sourdough fermented wheat germ as an ingredient, nutritional supplement and/or anticancer drug. PMID:24215546

  4. The hydrological context determines the beta-diversity of aerobic anoxygenic phototrophic bacteria in European Arctic seas but does not favor endemism

    PubMed Central

    Lehours, Anne-Catherine; Jeanthon, Christian

    2015-01-01

    Despite an increasing number of studies over the last 15 years, aerobic anoxygenic photoheterotrophic (AAP) bacteria remain a puzzling functional group in terms of physiology, metabolism, and ecology. To contribute to a better knowledge of their environmental distribution, the present study aims at analyzing their diversity and structure at the boundary between the Norwegian, Greenland, and Barents Seas. The polymorphism of a marker gene encoding a sub-unit of the photosynthetic apparatus (pufM gene) was analyzed and attempted to be related to environmental parameters. The Atlantic or Arctic origin of water masses had a strong impact on the AAP bacterial community structure whose populations mostly belonged to the Alpha- and Gammaproteobacteria. A majority (>60%) of pufM sequences were affiliated to the Gammaproteobacteria reasserting that this class often represents the major component of the AAP bacterial community in oceanic regions. Two alphaproteobacterial groups dominate locally suggesting that they can constitute key players in this marine system transiently. We found that temperature is a major determinant of alpha diversity of AAP bacteria in this marine biome with specific clades emerging locally according to the partitioning of water masses. Whereas we expected specific AAP bacterial populations in this peculiar and newly explored ecosystem, most pufM sequences were highly related to sequences retrieved elsewhere. This observation highlights that the studied area does not favor AAP bacteria endemism but also opens new questions about the truthfulness of biogeographical patterns and on the extent of AAP bacterial diversity.

  5. Interactions of nisin and pediocin PA-1 with closely related lactic acid bacteria that manifest over 100-fold differences in bacteriocin sensitivity.

    PubMed Central

    Bennik, M H; Verheul, A; Abee, T; Naaktgeboren-Stoffels, G; Gorris, L G; Smid, E J

    1997-01-01

    The natural variation in the susceptibilities of gram-positive bacteria towards the bacteriocins nisin and pediocin PA-1 is considerable. This study addresses the factors associated with this variability for closely related lactic acid bacteria. We compared two sets of nonbacteriocinogenic strains for which the MICs of nisin and pediocin PA-1 differed 100- to 1,000-fold: Lactobacillus sake DSM20017 and L. sake DSM20497 and Pediococcus dextrinicus and Pediococcus pentosaccus. Strikingly, the bacteriocin-sensitive and -insensitive strains showed a similar concentration-dependent dissipation of their membrane potential (delta psi) after exposure to these bacteriocins. The bacteriocin-induced dissipation of delta psi below the MICs for the insensitive strains did not coincide with a reduction of intracellular ATP pools and glycolytic rates. This was not observed with the sensitive strains. Analysis of membrane lipid properties revealed minor differences in the phospho- and glycolipid compositions of both sets of strains. The interactions of the bacteriocins with strain-specific lipids were not significantly different in a lipid monolayer assay. Further lipid analysis revealed higher in situ membrane fluidity of the bacteriocin-sensitive Pediococcus strain compared with that for the insensitive strain, but the opposite was found for the L. sake strains. Our results provide evidence that the association of bacteriocins with the cell membrane and their subsequent insertion take place in a similar way for cells that have a high or a low natural tolerance towards bacteriocins. For insensitive strains, overall membrane constitution rather than mere membrane fluidity may preclude the formation of pores with sufficient diameters and lifetimes to ultimately cause cell death. PMID:9293015

  6. Screening and characterization of purine nucleoside degrading lactic acid bacteria isolated from Chinese sauerkraut and evaluation of the serum uric acid lowering effect in hyperuricemic rats.

    PubMed

    Li, Ming; Yang, Dianbin; Mei, Lu; Yuan, Lin; Xie, Ao; Yuan, Jieli

    2014-01-01

    Hyperuricemia is well known as the cause of gout. In recent years, it has also been recognized as a risk factor for arteriosclerosis, cerebrovascular and cardiovascular diseases, and nephropathy in diabetic patients. Foods high in purine compounds are more potent in exacerbating hyperuricemia. Therefore, the development of probiotics that efficiently degrade purine compounds is a promising potential therapy for the prevention of hyperuricemia. In this study, fifty-five lactic acid bacteria isolated from Chinese sauerkraut were evaluated for the ability to degrade inosine and guanosine, the two key intermediates in purine metabolism. After a preliminary screening based on HPLC, three candidate strains with the highest nucleoside degrading rates were selected for further characterization. The tested biological characteristics of candidate strains included acid tolerance, bile tolerance, anti-pathogenic bacteria activity, cell adhesion ability, resistance to antibiotics and the ability to produce hydrogen peroxide. Among the selected strains, DM9218 showed the best probiotic potential compared with other strains despite its poor bile resistance. Analysis of 16S rRNA sequences showed that DM9218 has the highest similarity (99%) to Lactobacillus plantarum WCFS1. The acclimated strain DM9218-A showed better resistance to 0.3% bile salt, and its survival in gastrointestinal tract of rats was proven by PCR-DGGE. Furthermore, the effects of DM9218-A in a hyperuricemia rat model were evaluated. The level of serum uric acid in hyperuricemic rat can be efficiently reduced by the intragastric administration of DM9218-A (P<0.05). The preventive treatment of DM9218-A caused a greater reduction in serum uric acid concentration in hyperuricemic rats than the later treatment (P<0.05). Our results suggest that DM9218-A may be a promising candidate as an adjunctive treatment in patients with hyperuricemia during the onset period of disease. DM9218-A also has potential as a probiotic in the prevention of hyperuricemia in the normal population. PMID:25184445

  7. Screening and Characterization of Purine Nucleoside Degrading Lactic Acid Bacteria Isolated from Chinese Sauerkraut and Evaluation of the Serum Uric Acid Lowering Effect in Hyperuricemic Rats

    PubMed Central

    Mei, Lu; Yuan, Lin; Xie, Ao; Yuan, Jieli

    2014-01-01

    Hyperuricemia is well known as the cause of gout. In recent years, it has also been recognized as a risk factor for arteriosclerosis, cerebrovascular and cardiovascular diseases, and nephropathy in diabetic patients. Foods high in purine compounds are more potent in exacerbating hyperuricemia. Therefore, the development of probiotics that efficiently degrade purine compounds is a promising potential therapy for the prevention of hyperuricemia. In this study, fifty-five lactic acid bacteria isolated from Chinese sauerkraut were evaluated for the ability to degrade inosine and guanosine, the two key intermediates in purine metabolism. After a preliminary screening based on HPLC, three candidate strains with the highest nucleoside degrading rates were selected for further characterization. The tested biological characteristics of candidate strains included acid tolerance, bile tolerance, anti-pathogenic bacteria activity, cell adhesion ability, resistance to antibiotics and the ability to produce hydrogen peroxide. Among the selected strains, DM9218 showed the best probiotic potential compared with other strains despite its poor bile resistance. Analysis of 16S rRNA sequences showed that DM9218 has the highest similarity (99%) to Lactobacillus plantarum WCFS1. The acclimated strain DM9218-A showed better resistance to 0.3% bile salt, and its survival in gastrointestinal tract of rats was proven by PCR-DGGE. Furthermore, the effects of DM9218-A in a hyperuricemia rat model were evaluated. The level of serum uric acid in hyperuricemic rat can be efficiently reduced by the intragastric administration of DM9218-A (P<0.05). The preventive treatment of DM9218-A caused a greater reduction in serum uric acid concentration in hyperuricemic rats than the later treatment (P<0.05). Our results suggest that DM9218-A may be a promising candidate as an adjunctive treatment in patients with hyperuricemia during the onset period of disease. DM9218-A also has potential as a probiotic in the prevention of hyperuricemia in the normal population. PMID:25184445

  8. Isolation and characterization of potential lactic acid bacteria (LAB) from freshwater fish processing wastes for application in fermentative utilisation of fish processing waste

    PubMed Central

    R, Jini; HC, Swapna; Rai, Amit Kumar; R, Vrinda; PM, Halami; NM, Sachindra; N, Bhaskar

    2011-01-01

    Proteolytic and/or lipolytic lactic acid bacteria (LAB) were isolated from visceral wastes of different fresh water fishes. LAB count was found to be highest in case of visceral wastes of Mrigal (5.88 log cfu/g) and lowest in that of tilapia (4.22 log cfu/g). Morphological, biochemical and molecular characterization of the selected LAB isolates were carried out. Two isolates FJ1 (E. faecalis NCIM5367) and LP3 (P. acidilactici NCIM5368) showed both proteolytic and lipolytic properties. All the six native isolates selected for characterization showed antagonistic properties against several human pathogens. All the native isolates were sensitive to antibiotics cephalothin and clindamycin; and, resistant to cotrimoxazole and vancomycin. Considering individually, P. acidilactici FM37, P. acidilactici MW2 and E. faecalis FD3 were sensitive to erythromycin. The two strains FJ1 (E. faecalis NCIM 5367) and LP3 (P. acidilactici NCIM 5368) that had both proteolytic and lipolytic properties have the potential for application in fermentative recovery of lipids and proteins from fish processing wastes. PMID:24031786

  9. Isolation and characterization of potential lactic acid bacteria (LAB) from freshwater fish processing wastes for application in fermentative utilisation of fish processing waste.

    PubMed

    R, Jini; Hc, Swapna; Rai, Amit Kumar; R, Vrinda; Pm, Halami; Nm, Sachindra; N, Bhaskar

    2011-10-01

    Proteolytic and/or lipolytic lactic acid bacteria (LAB) were isolated from visceral wastes of different fresh water fishes. LAB count was found to be highest in case of visceral wastes of Mrigal (5.88 log cfu/g) and lowest in that of tilapia (4.22 log cfu/g). Morphological, biochemical and molecular characterization of the selected LAB isolates were carried out. Two isolates FJ1 (E. faecalis NCIM5367) and LP3 (P. acidilactici NCIM5368) showed both proteolytic and lipolytic properties. All the six native isolates selected for characterization showed antagonistic properties against several human pathogens. All the native isolates were sensitive to antibiotics cephalothin and clindamycin; and, resistant to cotrimoxazole and vancomycin. Considering individually, P. acidilactici FM37, P. acidilactici MW2 and E. faecalis FD3 were sensitive to erythromycin. The two strains FJ1 (E. faecalis NCIM 5367) and LP3 (P. acidilactici NCIM 5368) that had both proteolytic and lipolytic properties have the potential for application in fermentative recovery of lipids and proteins from fish processing wastes. PMID:24031786

  10. Psychrotrophic lactic acid bacteria associated with production batch recalls and sporadic cases of early spoilage in Belgium between 2010 and 2014.

    PubMed

    Pothakos, Vasileios; Taminiau, Bernard; Huys, Geert; Nezer, Carine; Daube, Georges; Devlieghere, Frank

    2014-11-17

    Between 2010 and 2014 several spoilage cases in Belgium occurring in retail foodstuffs prior to the end of shelf-life have been reported to our laboratory. Overall, seven cases involved strictly psychrotrophic lactic acid bacteria (LAB) contamination in packaged and chilled-stored food products. The products derived either from recalls of entire production batches or as specimens of sporadic spoilage manifestations. Some of these samples were returned to the manufacturing companies by consumers who observed the alterations after purchasing the products. The products covered a wide range of foodstuffs (i.e. meat, dairy, vegetable, egg products and composite food) and denoted different spoilage defects. However, the microbiota determined by means of 16S rRNA gene high-throughput sequencing analysis underpin few LAB genera (i.e. Leuconostoc, Lactobacillus, Weissella and Lactococcus), which are frequently encountered nowadays as specific spoilage organisms (SSO) albeit overlooked by mesophilic enumeration methods due to their strictly psychrotrophic character. The present study confirms the spreading of psychrotrophic LAB in Belgian food processing environments leading to unexpected spoilage, corroborating their spoilage dynamics and prevalence in all kinds of packaged and refrigerated foodstuffs in Northern Europe. PMID:25268325

  11. Construction of theta-type shuttle vector for Leuconostoc and other lactic acid bacteria using pCB42 isolated from kimchi.

    PubMed

    Eom, Hyun-Ju; Moon, Jin-Seok; Cho, Seung Kee; Kim, Jeong Hwan; Han, Nam Soo

    2012-01-01

    The pCB42 plasmid from Leuconostoc citreum CB2567, a strain isolated from kimchi, was characterized, and a shuttle vector for Escherichia coli and lactic acid bacteria (LAB) was constructed. The pCB42 plasmid has a circular structure of 4312bp, a low G+C content, and no single-stranded DNA intermediates during replication, which indicates that pCB42 replicates via the theta-type replication mechanism. In silico analysis of this plasmid revealed 6 open reading frames: 1 transposase gene, 1 DNA-binding gene, 2 putative replication genes, and 2 unknown genes. The fragment encompassing ORF5 contains a functional plasmid replicon. This plasmid was capable of replicating in various LAB, including L. citreum, L. mesenteroides, Lactobacillus plantarum, Lb. reuteri, Lactococcus lactis, Streptococcus thermophilus, Weissella confusa, and Oenococcus oeni. The LAB-E. coli shuttle vector was constructed by ligating pCB42 and pEK104, and the resulting shuttle vector, pLeuCM42, showed a high segregational stability in L. citreum CB2567 after 100 generations of cell division. By using this shuttle vector, the ?-gal gene from Lb. plantarum was successfully expressed in the host strain, L. citreum CB2567. The pLeuCM42 shuttle vector can serve as a useful gene-delivery and expression tool for the genetic study or metabolic engineering of various strains of LAB. PMID:22133745

  12. Biodiversity and growth dynamics of lactic acid bacteria in artisanal PDO Ossau-Iraty cheeses made from raw ewe's milk with different starters.

    PubMed

    Feutry, Fabienne; Oneca, María; Berthier, Françoise; Torre, Paloma

    2012-02-01

    The biodiversity and growth dynamics of Lactic Acid Bacteria (LAB) in farm-house Ossau-Iraty cheeses were investigated from vat milk to 180 days of ripening in six independent batches made from six raw ewe's milks using five typical cheese-making methods. Commercial starter S1 was used for three batches, starter S1 combined with S2 for one batch and no starter for two batches. Up to ten LAB species from five genera and up to two strains per species were identified per milk; up to eleven species from five genera and up to three strains per species were identified per cheese. Lactococcus lactis, Lactobacillus paracasei, Enterococcus faecalis, Enterococcus faecium, Enterococcus durans, and Leuconostoc mesenteroides were detected in all cheeses. Lactococci reached the highest counts irrespective of the milk and starter used. Lactococci and enterococci increased during manufacture, and mesophilic lactobacilli increased during ripening. Strain and species numbers, the percentage of isolates originating from the raw milk, maximum counts of each genus/species and time for reaching them, all varied according to whether or not a starter was used and the composition of the starter. The genotypes of strains within species varied according to the raw milk used. This generated distinct LAB microbiotas throughout manufacture and ripening that will certainly impact on the characteristics of the ripened cheeses. PMID:22029916

  13. Isolation and characterization of lactic acid bacteria from Yan-dong-gua (fermented wax gourd), a traditional fermented food in Taiwan.

    PubMed

    Lan, Wei-Tse; Chen, Yi-Sheng; Yanagida, Fujitoshi

    2009-12-01

    Yan-dong-gua (fermented wax gourd; a traditional fermented food in Taiwan) samples were collected at five time intervals from a fixed fermenting bucket. Eighty-five cultures of lactic acid bacteria (LAB) were isolated from Yan-dong-gua samples, and the isolates were divided into classes by phenotype and then groups by restriction fragment length polymorphism analysis and sequencing of 16S ribosomal DNA. Phenotypic and biochemical characteristics identified two bacterial groups (A and B) and showed that the majority of the isolates were heterofermentative LAB. Weissella cibaria was the major LAB found during the initial fermentation of yan-dong-gua. However, it was mostly replaced by W. paramesenteroides after 5 days of fermentation. All isolated LAB were able to grow in MRS broth containing 6% NaCl. Furthermore, the antibacterial activities of the isolates were determined, and five of the isolates showed inhibitory activities against the indicator strain Lactobacillus sakei subsp. sakei JCM 1157(T). These results suggest that W. cibaria and W. paramesenteroides are the main LAB present during the fermentation of yan-dong-gua. This is the first report describing the distribution and varieties of LAB that exist in the yan-dong-gua fermentation process. PMID:19914580

  14. Potentially probiotic and bioprotective lactic acid bacteria starter cultures antagonise the Listeria monocytogenes adhesion to HT29 colonocyte-like cells.

    PubMed

    Garriga, M; Rubio, R; Aymerich, T; Ruas-Madiedo, P

    2015-01-01

    The capability of five lactic acid bacteria (LAB) to counteract the adhesion of Listeria monocytogenes to the epithelial intestinal cell line HT29 was studied. The highest adhesion ability to HT29 was achieved by the intestinal strain Lactobacillus rhamnosus CTC1679, followed by the meat-derived strains Lactobacillus sakei CTC494 and Enterococcus faecium CTC8005. Surprisingly, the meat strains showed significantly better adhesion to HT29 than two faecal isolates of Lactobacillus casei and even significantly higher than the reference strain L. rhamnosus GG. Additionally, the anti-listerial, bacteriocin-producer starter culture L. sakei CTC494 was able to significantly reduce the adhesion of L. monocytogenes to HT29 in experiments of exclusion, competition and inhibition. The performance was better than the faecal isolate L. rhamnosus CTC1679. Our results reinforce the fact that the ability of LAB to interact with a host epithelium model, as well as to antagonise with foodborne pathogens, is a strain-specific characteristic. Additionally, it is underlined that this trait is not dependent on the origin of the bacterium, since some food LAB behave better than intestinal ones. Therefore, the search for novel strains in food niches is a suitable approach to find those with potential health benefits. These strains are likely pre-adapted to the food environment, which would make their inclusion in the formulation of probiotic foods more feasible. PMID:25488261

  15. Phages of lactic acid bacteria: the role of genetics in understanding phage-host interactions and their co-evolutionary processes.

    PubMed

    Mahony, Jennifer; Ainsworth, Stuart; Stockdale, Stephen; van Sinderen, Douwe

    2012-12-20

    Dairy fermentations are among the oldest food processing applications, aimed at preservation and shelf-life extension through the use of lactic acid bacteria (LAB) starter cultures, in particular strains of Lactococcus lactis, Streptococcus thermophilus, Lactobacillus spp. and Leuconostoc spp. Traditionally this was performed by continuous passaging of undefined cultures from a finished fermentation to initiate the next fermentation. More recently, consumer demands on consistent and desired flavours and textures of dairy products have led to a more defined approach to such processes. Dairy (starter) companies have responded to the need to define the nature and complexity of the starter culture mixes, and dairy fermentations are now frequently based on defined starter cultures of low complexity, where each starter component imparts specific technological properties that are desirable to the product. Both mixed and defined starter culture approaches create the perfect environment for the proliferation of (bacterio)phages capable of infecting these LAB. The repeated use of the same starter cultures in a single plant, coupled to the drive towards higher and consistent production levels, increases the risk and negative impact of phage infection. In this review we will discuss recent advances in tracking the adaptation of phages to the dairy industry, the advances in understanding LAB phage-host interactions, including evolutionary and genomic aspects. PMID:23089252

  16. The impact of fermentation with exopolysaccharide producing lactic acid bacteria on rheological, chemical and sensory properties of pureed carrots (Daucus carota L.).

    PubMed

    Juvonen, Riikka; Honkapää, Kaisu; Maina, Ndegwa H; Shi, Qiao; Viljanen, Kaarina; Maaheimo, Hannu; Virkki, Liisa; Tenkanen, Maija; Lantto, Raija

    2015-08-17

    Fermentation with lactic acid bacteria (LAB) offers a natural means to modify technological and nutritional properties of foods and food ingredients. This study explored the impact of fermentation with different exopolysaccharide (EPS) producing LAB on rheological, chemical and sensory properties of puréed carrots in water, as a vegetable model, with the focus on texture formation. The screening of 37 LAB strains for starter selection revealed 16 Lactobacillus, Leuconostoc and Weissella strains capable of EPS (dextran, levan, and/or ?-glucan) production in the carrot raw material. Fermentations with five out of six selected EPS producers modified perceived texture of the liquid carrot model (p<0.05). The formation of low-branched dextran correlated with perceived thickness, whereas the production of ?-glucan correlated with perceived elasticity. Low-branched dextran producing Weissella confusa and Leuconostoc lactis strains produced thick texture accompanied by pleasant odour and flavour. The fermentation with the selected EPS-producing LAB strains is a promising clean label approach to replace hydrocolloid additives as texturizers in vegetable containing products, not only carrot. PMID:26001525

  17. Phages of lactic acid bacteria: The role of genetics in understanding phage-host interactions and their co-evolutionary processes

    SciTech Connect

    Mahony, Jennifer, E-mail: j.mahony@ucc.ie [Department of Microbiology, University College Cork, Western Road, Cork (Ireland)] [Department of Microbiology, University College Cork, Western Road, Cork (Ireland); Ainsworth, Stuart; Stockdale, Stephen [Department of Microbiology, University College Cork, Western Road, Cork (Ireland)] [Department of Microbiology, University College Cork, Western Road, Cork (Ireland); Sinderen, Douwe van, E-mail: d.vansinderen@ucc.ie [Department of Microbiology, University College Cork, Western Road, Cork (Ireland); Alimentary Pharmabiotic Centre, Biosciences Institute, University College Cork, Western Road, Cork (Ireland)

    2012-12-20

    Dairy fermentations are among the oldest food processing applications, aimed at preservation and shelf-life extension through the use of lactic acid bacteria (LAB) starter cultures, in particular strains of Lactococcus lactis, Streptococcus thermophilus, Lactobacillus spp. and Leuconostoc spp. Traditionally this was performed by continuous passaging of undefined cultures from a finished fermentation to initiate the next fermentation. More recently, consumer demands on consistent and desired flavours and textures of dairy products have led to a more defined approach to such processes. Dairy (starter) companies have responded to the need to define the nature and complexity of the starter culture mixes, and dairy fermentations are now frequently based on defined starter cultures of low complexity, where each starter component imparts specific technological properties that are desirable to the product. Both mixed and defined starter culture approaches create the perfect environment for the proliferation of (bacterio)phages capable of infecting these LAB. The repeated use of the same starter cultures in a single plant, coupled to the drive towards higher and consistent production levels, increases the risk and negative impact of phage infection. In this review we will discuss recent advances in tracking the adaptation of phages to the dairy industry, the advances in understanding LAB phage-host interactions, including evolutionary and genomic aspects.

  18. Effects of the fermentation product of herbs by lactic acid bacteria against phytopathogenic filamentous fungi and on the growth of host plants.

    PubMed

    Kuwaki, Shinsuke; Ohhira, Iichiro; Takahata, Masumi; Hirota, Atsuko; Murata, Yoshiyuki; Tada, Mikiro

    2004-01-01

    The fermentation product of herbs by lactic acid bacteria (FHL) was assayed for antifungal activities against Rosellinia necatrix, Helicobasidium mompa, Fusarium oxysporum, Pythium graminicola and Pyricularia oryzae. FHL completely inhibited the growth of R. necatrix, H. mompa, P. graminicola and P. oryzae, and reduced the growth of F. oxysporum by 35%. When the seeds of Medicago sativa L. (alfalfa), Asparagus officinalis L. (asparagus), Brassica campestris L. (komatsuna), Oryza sativa L. (rice), Spinacia oleracea L. (spinach), Festuca arundinacea Schreb. (tall fescue), and Lycopersicum esculentum Mill. (tomato) were put on plates containing 0.69 mg/ml FHL, their germination rates did not decrease. The root elongation of A. officinalis, B. campestris, O. sativa, and L. esculentum seedlings was suppressed on plates containing 6.92 mg/ml FHL, but the root elongation of M. sativa was not suppressed on the 6.92 mg/ml FHL plate. When FHL was diluted to less than 1.73 mg/ml, the diluted FHL solution did not suppress the germination of B. campestris seeds, but it suppressed the root elongation of B. campestris seedlings. An FHL concentration higher than 0.35 mg/ml hastened the growth of seedlings of B. campestris in the presence of a chemical fertilizer but delayed the growth of these seedlings in the absence of the chemical fertilizer, suggesting that inorganic elements could affect the efficiency of FHL. PMID:16233688

  19. Lactic acid bacteria and natural antimicrobials to improve the safety and shelf-life of minimally processed sliced apples and lamb's lettuce.

    PubMed

    Siroli, Lorenzo; Patrignani, Francesca; Serrazanetti, Diana I; Tabanelli, Giulia; Montanari, Chiara; Gardini, Fausto; Lanciotti, Rosalba

    2015-05-01

    Outbreaks of food-borne disease associated with the consumption of fresh and minimally processed fruits and vegetables have increased dramatically over the last few years. Traditional chemical sanitizers are unable to completely eradicate or kill the microorganisms on fresh produce. These conditions have stimulated research to alternative methods for increasing food safety. The use of protective cultures, particularly lactic acid bacteria (LAB), has been proposed for minimally processed products. However, the application of bioprotective cultures has been limited at the industrial level. From this perspective, the main aims of this study were to select LAB from minimally processed fruits and vegetables to be used as biocontrol agents and then to evaluate the effects of the selected strains, alone or in combination with natural antimicrobials (2-(E)-hexenal/hexanal, 2-(E)-hexenal/citral for apples and thyme for lamb's lettuce), on the shelf-life and safety characteristics of minimally processed apples and lamb's lettuce. The results indicated that applying the Lactobacillus plantarum strains CIT3 and V7B3 to apples and lettuce, respectively, increased both the safety and shelf-life. Moreover, combining the selected strains with natural antimicrobials produced a further increase in the shelf-life of these products without detrimental effects on the organoleptic qualities. PMID:25583340

  20. Screening for lactic acid bacteria capable of inhibiting Campylobacter jejuni in in vitro simulations of the broiler chicken caecal environment.

    PubMed

    Robyn, J; Rasschaert, G; Messens, W; Pasmans, F; Heyndrickx, M

    2012-12-01

    Thermotolerant Campylobacter spp., specifically Campylobacter jejuni and Campylobacter coli, are the most common bacterial causes of human gastroenteritis in developed countries. Consumption of improperly prepared poultry products and cross contamination are among the main causes of human campylobacteriosis. The aim of this study was to identify lactic acid bacterial (LAB) strains capable of inhibiting C. jejuni growth in initial in vitro trials ('spot-on-lawn' method), as well as in batch fermentation studies mimicking the broiler caecal environment. These experiments served as an indication for using these strains to decrease the capability of Campylobacter to colonise and grow in the chicken caeca during primary production, with the aim of reducing the number of human campylobacteriosis cases. A total of 1,150 LAB strains were screened for anti-Campylobacter activity. Six strains were selected: members of the species Lactobacillus reuteri, Lactobacillus agilis, Lactobacillus helveticus, Lactobacillus salivarius, Enterococcus faecalis and Enterococcus faecium. After treatment with catalase, proteinase K and a-chymotrypsin, anti-Campylobacter activity of cell-free culture supernatant fluid (CSF) for all six strains was retained, which indicated that activity was probably not exerted by bacteriocin production. Based on the activity found in CSF, the compounds produced by the selected strains are secreted and do not require presence of live bacterial producer cells for activity. During initial in vitro fermentation experiments, the E. faecalis strain exhibited the highest inhibitory activity for C. jejuni and was selected for further fermentation experiments. In these experiments we tested for therapeutic or protective effects of the E. faecalis strain against C. jejuni MB 4185 infection under simulated broiler caecal growth conditions. The best inhibition results were obtained when E. faecalis was inoculated before the C. jejuni strain, lowering C. jejuni counts at least one log compared to a positive control. This effect was already observed 6 h after C. jejuni inoculation. PMID:23234730

  1. Resistance of potential probiotic lactic acid bacteria and bifidobacteria of African and European origin to antimicrobials: determination and transferability of the resistance genes to other bacteria.

    PubMed

    Ouoba, Labia Irene Ivette; Lei, Vicki; Jensen, Lars B

    2008-01-31

    Probiotic bacteria and starter cultures of Lactobacillus, Weissella and Bifidobacterium of African and European origins were studied and compared for their susceptibility to antimicrobials. The study included, for all isolates, determination of MICs (Minimal Inhibitory Concentration) for 24 antimicrobials, detection of resistance genes by PCR reactions using specific primers and sequencing of positive amplicons. The ability of Lb. reuteri from Africa to transfer the erythromycin resistance gene erm(B) to closely related bacteria was investigated by conjugation. Variations were observed and high levels of intrinsic resistance were found among the tested species. Positive amplicons were obtained for resistance genes encoding aminoglycoside (aph(3')-III, aadA, aadE) and tetracycline (tet(S)) from isolates from Europe and macrolide (erm(B)) from an isolate from Africa. However, only the erm(B) gene found in Lb. reuteri L4: 12002 from Africa contained a homologous sequence to previously published sequences. This gene could be transferred in vitro to enterococci. Higher prevalence of phenotypic resistance for aminoglycoside was found in isolates from Europe. PMID:18063151

  2. Probiotic viability and storage stability of yogurts and fermented milks prepared with several mixtures of lactic acid bacteria.

    PubMed

    Mani-López, E; Palou, E; López-Malo, A

    2014-05-01

    Currently, the food industry wants to expand the range of probiotic yogurts but each probiotic bacteria offers different and specific health benefits. Little information exists on the influence of probiotic strains on physicochemical properties and sensory characteristics of yogurts and fermented milks. Six probiotic yogurts or fermented milks and 1 control yogurt were prepared, and we evaluated several physicochemical properties (pH, titratable acidity, texture, color, and syneresis), microbial viability of starter cultures (Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus) and probiotics (Lactobacillus acidophilus, Lactobacillus casei, and Lactobacillus reuteri) during fermentation and storage (35 d at 5°C), as well as sensory preference among them. Decreases in pH (0.17 to 0.50 units) and increases in titratable acidity (0.09 to 0.29%) were observed during storage. Only the yogurt with S. thermophilus, L. delbrueckii ssp. bulgaricus, and L. reuteri differed in firmness. No differences in adhesiveness were determined among the tested yogurts, fermented milks, and the control. Syneresis was in the range of 45 to 58%. No changes in color during storage were observed and no color differences were detected among the evaluated fermented milk products. Counts of S. thermophilus decreased from 1.8 to 3.5 log during storage. Counts of L. delbrueckii ssp. bulgaricus also decreased in probiotic yogurts and varied from 30 to 50% of initial population. Probiotic bacteria also lost viability throughout storage, although the 3 probiotic fermented milks maintained counts ? 10(7)cfu/mL for 3 wk. Probiotic bacteria had variable viability in yogurts, maintaining counts of L. acidophilus ? 10(7) cfu/mL for 35 d, of L. casei for 7d, and of L. reuteri for 14 d. We found no significant sensory preference among the 6 probiotic yogurts and fermented milks or the control. However, the yogurt and fermented milk made with L. casei were better accepted. This study presents relevant information on physicochemical, sensory, and microbial properties of probiotic yogurts and fermented milks, which could guide the dairy industry in developing new probiotic products. PMID:24745665

  3. Aerobic Heterotrophic Bacteria Indigenous to pH 2.8 Acid Mine Water: Microscopic Examination of Acid Streamers

    PubMed Central

    Dugan, Patrick R.; MacMillan, Carol B.; Pfister, Robert M.

    1970-01-01

    “Acid streamers” found in acid coal mine drainage consist of bacteria trapped within an extracellular fibrillar polymer network. Inorganic compounds also precipitate within the polymer network. Several bacteria which appear to be different and are presumed to be different species are associated in the slimy mass of the “acid streamers.” The “streamers” contain individual microcolonies or microcosms that can be recognized by a selective polysaccharide stain, which suggests that the slime streamer is a conglomeration of polymers produced by more than one species. Images PMID:4191322

  4. Arsenate reduction and mobilization in the presence of indigenous aerobic bacteria obtained from high arsenic aquifers of the Hetao basin, Inner Mongolia.

    PubMed

    Guo, Huaming; Liu, Zeyun; Ding, Susu; Hao, Chunbo; Xiu, Wei; Hou, Weiguo

    2015-08-01

    Intact aquifer sediments were collected to obtain As-resistant bacteria from the Hetao basin. Two strains of aerobic As-resistant bacteria (Pseudomonas sp. M17-1 and Bacillus sp. M17-15) were isolated from the aquifer sediments. Those strains exhibited high resistances to both As(III) and As(V). Results showed that both strains had arr and ars genes, and led to reduction of dissolved As(V), goethite-adsorbed As(V), scorodite As(V) and sediment As(V), in the presence of organic carbon as the carbon source. After reduction of solid As(V), As release was observed from the solids to solutions. Strain M17-15 had a higher ability than strain M17-1 in reducing As(V) and promoting the release of As. These results suggested that the strains would mediate As(V) reduction to As(III), and thereafter release As(III), due to the higher mobility of As(III) in most aquifer systems. The processes would play an important role in genesis of high As groundwater. PMID:25863882

  5. Effect of Time and Sand Abrasion on Recovery of Aerobic Bacteria, Escherichia coli, and Coliforms from Broiler Carcasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An experiment was conducted to determine the effect of rinse time and a sand abrasion on bacteria from whole broiler carcass rinses (WCR). Twelve eviscerated broiler carcasses were obtained from a commercial processing plant prior to chilling. Six carcasses were rinsed in 400 mL of 2.0% buffered pe...

  6. Interference by Aerobic and Anaerobic Bacteria in Children With Recurrent Group A b-Hemolytic Streptococcal Tonsillitis

    Microsoft Academic Search

    Itzhak Brook; Alan E. Gober

    1999-01-01

    Objective: To compare the frequency of recovery of aero- bic and anaerobic bacteria with interfering capability of group A b-hemolytic streptococci (GABHS) in the ton- sils of children with and without a history of recurrent GABHS pharyngotonsillitis. Patients and Methods: Tonsillar cultures were taken from a group of 20 children with and 20 without history of recurrent GABHS pharyngotonsillitis. Results:

  7. Reduction of Escherichia coli O157:H7 in Fresh Spinach, using lactic acid bacteria and chlorine as a multihurdle intervention.

    PubMed

    Gragg, S E; Brashears, M M

    2010-02-01

    A 12-day shelf life study was conducted at 7 degrees C to determine whether Escherichia coli O157:H7 on spinach can be controlled effectively by selected strains of lactic acid bacteria (LAB) alone or in combination with chlorine as a multihurdle intervention. The multihurdle intervention consisted of both LAB and chlorine and was applied to spinach as a rinse and evaluated in comparison to LAB alone and chlorine and water rinses. Reductions achieved by all treatments also were compared with those observed for an inoculated control. The spinach was inoculated by submersion in a solution containing an E. coli O157:H7 cocktail at 1.0 x 10(6) CFU/ml. LAB were applied postharvest at a concentration of 2.0 x 10(8) CFU/ml, and 200 ppm of chlorine was used for the chlorine rinse. All spinach samples were packaged in commercial packaging, held in a retail display case, and tested for E. coli O157:H7 on days 0, 1, 3, 6, 9, and 12 using the Neo-Grid filtration system and CHROMagar. Survival of LAB throughout the shelf life also was determined. Significant reductions in pathogen populations were achieved by water (P = 0.0008), LAB (P < 0.0001), chlorine (P < 0.0001), and multihurdle (P < 0.0001) treatments when compared with controls. The multihurdle treatment produced the greatest reduction from control populations, a reduction of 1.91 log CFU/ml. This reduction was significantly greater than that achieved with water (P < 0.0001), LAB (P = 0.0025), and chlorine (P < 0.0001) alone, indicating that the application of chlorine and LAB is most effective as a combination treatment. The results obtained from this study indicate that the industry standard chlorine wash may be more effective when applied in combination with LAB. PMID:20132683

  8. Characterization of lactic acid bacteria isolated from a Greek dry-fermented sausage in respect of their technological and probiotic properties.

    PubMed

    Papamanoli, E; Tzanetakis, N; Litopoulou-Tzanetaki, E; Kotzekidou, P

    2003-10-01

    A total of 147 lactic acid bacteria was isolated from two types of naturally fermented dry sausages at four different stages of the ripening process studied in order to select the most suitable strains according to their technological characteristics including probiotic properties and antimicrobial activity against food-borne pathogens. Identification of the isolates revealed that 90% were lactobacilli, 4% enterococci, 3% Pediococcus sp. and sporadic isolates of Weissella viridescens, Leuconostoc pseudomesenteroides, and Leuconostoc sp. The isolated strains of Lactobacillus sakei (49 isolates), Lactobacillus curvatus (24 isolates) and Lactobacillus plantarum (7 isolates) were further characterized. All strains could grow at 15 °C, whereas the majority of the strains was able to grow in the presence of 6.5% NaCl and on acetate agar. The enzymatic potential of the strains was evaluated using the API ZYM system. During in vitro investigations all strains exhibited high leucine and valine aminopeptidase activities and moderate acid phosphatase and phosphohydrolase activities. Some strains showed very weak lipolytic activity. The enzyme profiling is an important factor for selection of strains as starter cultures. A large majority of the strains tolerated 0.1% bile salts whereas 58% of Lactobacillus curvatus strains and all Lactobacillus plantarum strains were resistant to 0.3% bile salts. All Lactobacillus sakei strains and the majority of Lactobacillus curvatus and Lactobacillus plantarum strains exhibited an anti-listerial activity against three Listeria monocytogenes strains. A percentage of 75, 50 and 29% of Lactobacillus sakei, L. curvatus and L. plantarum strains, respectively, could inhibit two Staphylococcus aureus strains. The contribution of the selected strains to a possible inhibition of Listeria monocytogenes and S. aureus in situ on fermented meats would be of considerable interest to enhance the hygienic quality of these products. PMID:22063449

  9. Application' and validation of autochthonous lactic acid bacteria starter cultures for controlled leek fermentations and their influence on the antioxidant properties of leek.

    PubMed

    Wouters, D; Bernaert, N; Anno, N; Van Droogenbroeck, B; De Loose, M; Van Bockstaele, E; De Vuyst, L

    2013-07-15

    Leek (Allium ampeloprasum var. porrum) is one of Belgium's most important outdoor vegetables, mainly cultivated for its white shaft. Fermentation of leek offers opportunities in view of biomass valorization and product diversification. This study deals with the implementation and validation of starter cultures to perform controlled leek fermentations and to ensure a high quality of the end-products. Therefore, a thorough study of the fermentation microbiology and the influence of three starter culture strains (Lactobacillus plantarum IMDO 788, Lactobacillus sakei IMDO 1358, and Leuconostoc mesenteroides IMDO 1347) on the metabolite kinetics of leek fermentation and antioxidant properties of leek was performed. Overall, the application of lactic acid bacteria starter cultures resulted in a fast prevalence of the species involved, coupled to an accelerated acidification. Of the three starter cultures tested, the mixed starter culture of L. plantarum IMDO 788 and L. mesenteroides IMDO 1347 was most promising, as its application resulted in fermented leek of good microbiological quality and in a more extensive carbohydrate consumption, whereby diverse end-metabolites were produced. However, high residual fructose concentrations allowed yeast outgrowth, resulting in increased ethanol and glycerol concentrations, and indicated the lack of a prevailing strictly heterofermentative LAB species. The antioxidant capacity of fermented leek samples, as measured with the oxygen radical absorbance capacity assay, increased when starter cultures were used, whereas with regard to 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity, only leek fermented with L. sakei IMDO 1358 scored higher than spontaneously fermented leek. The total phenolic content was not influenced by the use of starter cultures, while the S-alk(en)yl-L-cysteine sulfoxides content decreased strongly. A preliminary sensory analysis revealed that the spontaneously fermented leek and the one obtained with the mixed starter culture were preferred by consumers, emphasizing again the importance of microbial successions in vegetable fermentations. PMID:23728429

  10. Population Diversity of Yeasts and Lactic Acid Bacteria in Pig Feed Fermented with Whey, Wet Wheat Distillers' Grains, or Water at Different Temperatures?

    PubMed Central

    Olstorpe, Matilda; Lyberg, Karin; Lindberg, Jan Erik; Schnürer, Johan; Passoth, Volkmar

    2008-01-01

    The diversity of populations of yeast and lactic acid bacteria (LAB) in pig feeds fermented at 10, 15, or 20°C was characterized by rRNA gene sequencing of isolates. The feeds consisted of a cereal grain mix blended with wet wheat distillers' grains (WWDG feed), whey (W feed), or tap water (WAT feed). Fermentation proceeded for 5 days without disturbance, followed by 14 days of daily simulated feed outtakes, in which 80% of the contents were replaced with fresh feed mixtures. In WWDG feed, Pichia galeiformis became the dominant yeast species, independent of the fermentation temperature and feed change. The LAB population was dominated by Pediococcus pentosaceus at the start of the fermentation period. After 3 days, the Lactobacillus plantarum population started to increase in feeds at all temperatures. The diversity of LAB increased after the addition of fresh feed components. In W feed, Kluyveromyces marxianus dominated, but after the feed change, the population diversity increased. With increasing fermentation temperatures, there was a shift toward Pichia membranifaciens as the dominant species. L. plantarum was the most prevalent LAB in W feed. The WAT feed had a diverse microbial flora, and the yeast population changed throughout the whole fermentation period. Pichia anomala was the most prevalent yeast species, with increasing occurrence at higher fermentation temperatures. Pediococcus pentosaceus was the most prevalent LAB, but after the feed change, L. plantarum started to proliferate. The present study demonstrates that the species composition in fermented pig feed may vary considerably, even if viable cell counts indicate stable microbial populations. PMID:18223110

  11. Intravaginal Lactic Acid Bacteria Modulated Local and Systemic Immune Responses and Lowered the Incidence of Uterine Infections in Periparturient Dairy Cows

    PubMed Central

    Deng, Qilan; Odhiambo, John F.; Farooq, Umar; Lam, Tran; Dunn, Suzanna M.; Ametaj, Burim N.

    2015-01-01

    The objective of this investigation was to evaluate whether intravaginal infusion of a lactic acid bacteria (LAB) cocktail around parturition could influence the immune response, incidence rate of uterine infections, and the overall health status of periparturient dairy cows. One hundred pregnant Holstein dairy cows were assigned to 1 of the 3 experimental groups as follows: 1) one dose of LAB on wk -2 and -1, and one dose of carrier (sterile skim milk) on wk +1 relative to the expected day of parturition (TRT1); 2) one dose of LAB on wk -2, -1, and +1 (TRT2), and 3) one dose of carrier on wk -2, -1, and +1 (CTR). The LAB were a lyophilized culture mixture composed of Lactobacillus sakei FUA3089, Pediococcus acidilactici FUA3138, and Pediococcus acidilactici FUA3140 with a cell count of 108-109 cfu/dose. Blood samples and vaginal mucus were collected once a week from wk -2 to +3 and analyzed for content of serum total immunoglobulin G (IgG), lipopolysaccharide-binding protein (LBP), serum amyloid A (SAA), haptoglobin (Hp), tumor necrosis factor (TNF), interleukin (IL)-1, IL-6, and vaginal mucus secretory IgA (sIgA). Clinical observations including rectal temperature, vaginal discharges, retained placenta, displaced abomasum, and laminitis were monitored from wk -2 to +8 relative to calving. Results showed that intravaginal LAB lowered the incidence of metritis and total uterine infections. Intravaginal LAB also were associated with lower concentrations of systemic LBP, an overall tendency for lower SAA, and greater vaginal mucus sIgA. No differences were observed for serum concentrations of Hp, TNF, IL-1, IL-6 and total IgG among the treatment groups. Administration with LAB had no effect on the incidence rates of other transition cow diseases. Overall intravaginal LAB lowered uterine infections and improved local and systemic immune responses in the treated transition dairy cows. PMID:25919010

  12. Characterization of Non-Starter Lactic Acid Bacteria from Italian Ewe Cheeses Based on Phenotypic, Genotypic, and Cell Wall Protein Analyses

    PubMed Central

    De Angelis, M.; Corsetti, A.; Tosti, N.; Rossi, J.; Corbo, M. R.; Gobbetti, M.

    2001-01-01

    Non-starter lactic acid bacteria (NSLAB) were isolated from 12 Italian ewe cheeses representing six different types of cheese, which in several cases were produced by different manufacturers. A total of 400 presumptive Lactobacillus isolates were obtained, and 123 isolates and 10 type strains were subjected to phenotypic, genetic, and cell wall protein characterization analyses. Phenotypically, the cheese isolates included 32% Lactobacillus plantarum isolates, 15% L. brevis isolates, 12% L. paracasei subsp. paracasei isolates, 9% L. curvatus isolates, 6% L. fermentum isolates, 6% L. casei subsp. casei isolates, 5% L. pentosus isolates, 3% L. casei subsp. pseudoplantarum isolates, and 1% L. rhamnosus isolates. Eleven percent of the isolates were not phenotypically identified. Although a randomly amplified polymorphic DNA (RAPD) analysis based on three primers and clustering by the unweighted pair group method with arithmetic average (UPGMA) was useful for partially differentiating the 10 type strains, it did not provide a species-specific DNA band or a combination of bands which permitted complete separation of all the species considered. In contrast, sodium dodecyl sulfate-polyacrylamide gel electrophoresis cell wall protein profiles clustered by UPGMA were species specific and resolved the NSLAB. The only exceptions were isolates phenotypically identified as L. plantarum and L. pentosus or as L. casei subsp. casei and L. paracasei subsp. paracasei, which were grouped together. Based on protein profiles, Italian ewe cheeses frequently contained four different species and 3 to 16 strains. In general, the cheeses produced from raw ewe milk contained a larger number of more diverse strains than the cheeses produced from pasteurized milk. The same cheese produced in different factories contained different species, as well as strains that belonged to the same species but grouped in different RAPD clusters. PMID:11319075

  13. Antimicrobial activity, antibiotic susceptibility and virulence factors of Lactic Acid Bacteria of aquatic origin intended for use as probiotics in aquaculture

    PubMed Central

    2013-01-01

    Background The microorganisms intended for use as probiotics in aquaculture should exert antimicrobial activity and be regarded as safe not only for the aquatic hosts but also for their surrounding environments and humans. The objective of this work was to investigate the antimicrobial/bacteriocin activity against fish pathogens, the antibiotic susceptibility, and the prevalence of virulence factors and detrimental enzymatic activities in 99 Lactic Acid Bacteria (LAB) (59 enterococci and 40 non-enterococci) isolated from aquatic animals regarded as human food. Results These LAB displayed a broad antimicrobial/bacteriocin activity against the main Gram-positive and Gram-negative fish pathogens. However, particular safety concerns based on antibiotic resistance and virulence factors were identified in the genus Enterococcus (86%) (Enterococcus faecalis, 100%; E. faecium, 79%). Antibiotic resistance was also found in the genera Weissella (60%), Pediococcus (44%), Lactobacillus (33%), but not in leuconostocs and lactococci. Antibiotic resistance genes were found in 7.5% of the non-enterococci, including the genera Pediococcus (12.5%) and Weissella (6.7%). One strain of both Pediococcus pentosaceus and Weissella cibaria carried the erythromycin resistance gene mef(A/E), and another two P. pentosaceus strains harboured lnu(A) conferring resistance to lincosamides. Gelatinase activity was found in E. faecalis and E. faecium (71 and 11%, respectively), while a low number of E. faecalis (5%) and none E. faecium exerted hemolytic activity. None enterococci and non-enterococci showed bile deconjugation and mucin degradation abilities, or other detrimental enzymatic activities. Conclusions To our knowledge, this is the first description of mef(A/E) in the genera Pediococcus and Weissella, and lnu(A) in the genus Pediococcus. The in vitro subtractive screening presented in this work constitutes a valuable strategy for the large-scale preliminary selection of putatively safe LAB intended for use as probiotics in aquaculture. PMID:23347637

  14. Central role of dynamic tidal biofilms dominated by aerobic hydrocarbonoclastic bacteria and diatoms in the biodegradation of hydrocarbons in coastal mudflats.

    PubMed

    Coulon, Frédéric; Chronopoulou, Panagiota-Myrsini; Fahy, Anne; Païssé, Sandrine; Goñi-Urriza, Marisol; Peperzak, Louis; Acuña Alvarez, Laura; McKew, Boyd A; Brussaard, Corina P D; Underwood, Graham J C; Timmis, Kenneth N; Duran, Robert; McGenity, Terry J

    2012-05-01

    Mudflats and salt marshes are habitats at the interface of aquatic and terrestrial systems that provide valuable services to ecosystems. Therefore, it is important to determine how catastrophic incidents, such as oil spills, influence the microbial communities in sediment that are pivotal to the function of the ecosystem and to identify the oil-degrading microbes that mitigate damage to the ecosystem. In this study, an oil spill was simulated by use of a tidal chamber containing intact diatom-dominated sediment cores from a temperate mudflat. Changes in the composition of bacteria and diatoms from both the sediment and tidal biofilms that had detached from the sediment surface were monitored as a function of hydrocarbon removal. The hydrocarbon concentration in the upper 1.5 cm of sediments decreased by 78% over 21 days, with at least 60% being attributed to biodegradation. Most phylotypes were minimally perturbed by the addition of oil, but at day 21, there was a 10-fold increase in the amount of cyanobacteria in the oiled sediment. Throughout the experiment, phylotypes associated with the aerobic degradation of hydrocarbons, including polycyclic aromatic hydrocarbons (PAHs) (Cycloclasticus) and alkanes (Alcanivorax, Oleibacter, and Oceanospirillales strain ME113), substantively increased in oiled mesocosms, collectively representing 2% of the pyrosequences in the oiled sediments at day 21. Tidal biofilms from oiled cores at day 22, however, consisted mostly of phylotypes related to Alcanivorax borkumensis (49% of clones), Oceanospirillales strain ME113 (11% of clones), and diatoms (14% of clones). Thus, aerobic hydrocarbon biodegradation is most likely to be the main mechanism of attenuation of crude oil in the early weeks of an oil spill, with tidal biofilms representing zones of high hydrocarbon-degrading activity. PMID:22407688

  15. Central Role of Dynamic Tidal Biofilms Dominated by Aerobic Hydrocarbonoclastic Bacteria and Diatoms in the Biodegradation of Hydrocarbons in Coastal Mudflats

    PubMed Central

    Coulon, Frédéric; Chronopoulou, Panagiota-Myrsini; Fahy, Anne; Païssé, Sandrine; Goñi-Urriza, Marisol; Peperzak, Louis; Acuña Alvarez, Laura; McKew, Boyd A.; Brussaard, Corina P. D.; Underwood, Graham J. C.; Timmis, Kenneth N.; Duran, Robert

    2012-01-01

    Mudflats and salt marshes are habitats at the interface of aquatic and terrestrial systems that provide valuable services to ecosystems. Therefore, it is important to determine how catastrophic incidents, such as oil spills, influence the microbial communities in sediment that are pivotal to the function of the ecosystem and to identify the oil-degrading microbes that mitigate damage to the ecosystem. In this study, an oil spill was simulated by use of a tidal chamber containing intact diatom-dominated sediment cores from a temperate mudflat. Changes in the composition of bacteria and diatoms from both the sediment and tidal biofilms that had detached from the sediment surface were monitored as a function of hydrocarbon removal. The hydrocarbon concentration in the upper 1.5 cm of sediments decreased by 78% over 21 days, with at least 60% being attributed to biodegradation. Most phylotypes were minimally perturbed by the addition of oil, but at day 21, there was a 10-fold increase in the amount of cyanobacteria in the oiled sediment. Throughout the experiment, phylotypes associated with the aerobic degradation of hydrocarbons, including polycyclic aromatic hydrocarbons (PAHs) (Cycloclasticus) and alkanes (Alcanivorax, Oleibacter, and Oceanospirillales strain ME113), substantively increased in oiled mesocosms, collectively representing 2% of the pyrosequences in the oiled sediments at day 21. Tidal biofilms from oiled cores at day 22, however, consisted mostly of phylotypes related to Alcanivorax borkumensis (49% of clones), Oceanospirillales strain ME113 (11% of clones), and diatoms (14% of clones). Thus, aerobic hydrocarbon biodegradation is most likely to be the main mechanism of attenuation of crude oil in the early weeks of an oil spill, with tidal biofilms representing zones of high hydrocarbon-degrading activity. PMID:22407688

  16. Proteins of novel lactic acid bacteria from Apis mellifera mellifera: an insight into the production of known extra-cellular proteins during microbial stress

    PubMed Central

    2013-01-01

    Background Lactic acid bacteria (LAB) has been considered a beneficial bacterial group, found as part of the microbiota of diverse hosts, including humans and various animals. However, the mechanisms of how hosts and LAB interact are still poorly understood. Previous work demonstrates that 13 species of Lactobacillus and Bifidobacterium from the honey crop in bees function symbiotically with the honeybee. They protect each other, their hosts, and the surrounding environment against severe bee pathogens, bacteria, and yeasts. Therefore, we hypothesized that these LAB under stress, i.e. in their natural niche in the honey crop, are likely to produce bioactive substances with antimicrobial activity. Results The genomic analysis of the LAB demonstrated varying genome sizes ranging from 1.5 to 2.2 mega-base pairs (Mbps) which points out a clear difference within the protein gene content, as well as specialized functions in the honeybee microbiota and their adaptation to their host. We demonstrate a clear variation between the secreted proteins of the symbiotic LAB when subjected to microbial stressors. We have identified that 10 of the 13 LAB produced extra-cellular proteins of known or unknown function in which some are arranged in interesting putative operons that may be involved in antimicrobial action, host interaction, or biofilm formation. The most common known extra-cellular proteins secreted were enzymes, DNA chaperones, S-layer proteins, bacteriocins, and lysozymes. A new bacteriocin may have been identified in one of the LAB symbionts while many proteins with unknown functions were produced which must be investigated further. Conclusions The 13 LAB symbionts likely play different roles in their natural environment defending their niche and their host and participating in the honeybee’s food production. These roles are partly played through producing extracellular proteins on exposure to microbial stressors widely found in natural occurring flowers. Many of these secreted proteins may have a putative antimicrobial function. In the future, understanding these processes in this complicated environment may lead to novel applications of honey crop LAB proteins. PMID:24148670

  17. Safety and quality parameters of ready-to-cook minced pork meat products supplemented with Helianthus tuberosus L. tubers fermented by BLIS producing lactic acid bacteria.

    PubMed

    Stimbirys, Arturas; Bartkiene, Elena; Siugzdaite, Jurate; Augeniene, Dovile; Vidmantiene, Daiva; Juodeikiene, Grazina; Maruska, Audrius; Stankevicius, Mantas; Cizeikiene, Dalia

    2015-07-01

    The aim of this study was to evaluate the influence of additives of Jerusalem artichoke (JA), fermented with P. acidilactici KTU05-7, P. pentosaceus KTU05-9, L. sakei KTU05-6, on the quality and safety parameters of ready - to cook - minced pork (RCMP). Fermented JA additives reduced pH of the meat products and decreased water holding capacity (WHC) from 2.01 till 2.93 %. Concentrations of biogenic amines in RCMP with additives of the lactic acid bacteria (LAB) - fermented JA were significantly lower comparing with control sample. The number of pathogenic bacteria in artificially contaminated meat samples was significantly reduced in case of LAB-fermented JA additives. The highest antimicrobial activity was obtained using P. acidilactici fermented JA additives. The amounts of microbial pathogens E. coli and Ent. faecalis, S. aureus and Streptococcus spp. were determined 3.41, 3.38, 3,96 and 4.74 log CFU/g correspondingly, whereas without LAB-fermented JA additives were 8.94, 7.75, 8.82 and 8.58 log CFU/g, correspondingly. A possibility to improve sensory properties (flavor) of RCMP using LAB fermented JA additives was investigated. The composition of volatile compounds of RCMP without additive and with LAB-fermented JA additives was analyzed using gas chromatography-mass spectrometry (GC-MS). The results of sensory evaluation of meat products supplemented with fermented JA additives revealed specific odor, which is pleasant and acceptable for consumers might be explainable that LAB-fermented JA additives have shown considerable differences mainly due to the accumulation of volatiles such as toluene, ethylbenzene, decane, undecane, 2 methyl undecane. N-morpholinomethyl-isopropyl-sulfide, 6-undecilamine and N,N-dimethyl-1-pentadecanamine were not determined in RCMP with LAB-fermented JA additives. The results obtained show, that P. acidilactici fermented JA 5 % additive is most suitable for the RCMP processing in order to prevent microbiological spoilage, increase volatile compounds and acceptability of the products. PMID:26139895

  18. Evaluation of the use of PCR and reverse transcriptase PCR for detection of pathogenic bacteria in biosolids from anaerobic digestors and aerobic composters.

    PubMed

    Burtscher, Carola; Wuertz, Stefan

    2003-08-01

    A PCR-based method and a reverse transcriptase PCR (RT-PCR)-based method were developed for the detection of pathogenic bacteria in organic waste, using Salmonella spp., Listeria monocytogenes, Yersinia enterocolitica, and Staphylococcus aureus as model organisms. In seeded organic waste samples, detection limits of less than 10 cells per g of organic waste were achieved after one-step enrichment of bacteria, isolation, and purification of DNA or RNA before PCR or RT-PCR amplification. To test the reproducibility and reliability of the newly developed methods, 46 unseeded samples were collected from diverse aerobic (composting) facilities and anaerobic digestors and analyzed by both culture-based classical and newly developed PCR-based procedures. No false-positive but some false-negative results were generated by the PCR- or RT-PCR-based methods after one-step enrichment when compared to the classical detection methods. The results indicated that the level of activity of the tested bacteria in unseeded samples was very low compared to that of freshly inoculated cells, preventing samples from reaching the cell density required for PCR-based detection after one-step enrichment. However, for Salmonella spp., a distinct PCR product could be obtained for all 22 nonamended samples that tested positive for Salmonella spp. by the classical detection procedure when a selective two-step enrichment (20 h in peptone water at 37 degrees C and 24 h in Rappaport Vassiliadis medium at 43 degrees C) was performed prior to nucleic acid extraction and PCR. Hence, the classical procedure was shortened, since cell plating and further differentiation of isolated colonies can be omitted, substituted for by highly sensitive and reliable detection based on nucleic acid extraction and PCR. Similarly, 2 of the 22 samples in which Salmonella spp. were detected also tested positive for Listeria monocytogenes according to a two-step enrichment procedure followed by PCR, compared to 3 samples that tested positive when classical isolation procedures were followed. The study shows that selective two-step enrichment is useful when very low numbers of bacterial pathogens must be detected in organic waste materials, such as biosolids. There were no false-positive results derived from DNA of dead cells in the waste sample, suggesting that it is not necessary to perform RT-PCR analyses when PCR is combined with selective enrichment. Large numbers of added nontarget bacteria did not affect detection of Salmonella spp., L. monocytogenes, and Y. enterocolitica but increased the detection limit of Staphylococcus aureus from <10 to 10(4) CFU/g of organic waste. Overall, the detection methods developed using seeded organic waste samples from one waste treatment facility (WTF) needed to be modified for satisfactory detection of pathogens in samples from other WTFs, emphasizing the need for extensive field testing of laboratory-derived PCR protocols. A survey of 13 WTFs in Germany revealed that all facilities complied with the German Biowaste Ordinance, which mandates that the end product after anaerobic digestion or aerobic composting be free of Salmonella In addition, all biosolids were free of L. monocytogenes, Staphylococcus aureus, and Y. enterocolitica, as evidenced by both classical and PCR-based detection methods. PMID:12902250

  19. New aerobic ammonium-dependent obligately oxalotrophic bacteria: description of Ammoniphilus oxalaticus gen. nov., sp. nov. and Ammoniphilus oxalivorans gen. nov., sp. nov.

    PubMed

    Zaitsev, G M; Tsitko, I V; Rainey, F A; Trotsenko, Y A; Uotila, J S; Stackebrandt, E; Salkinoja-Salonen, M S

    1998-01-01

    The genus Ammoniphilus is proposed for aerobic endospore-forming Gram-variable rod-shaped bacteria, which are ammonium-dependent, obligately oxalotrophic and haloalkalitolerant, oxidase- and catalase-positive, mesophilic and motile by peritrichous flagella. Cell wall contained two electron-dense layers. The external layer consists of a chain of electron-dense granules morphologically resembling the cellulosomes of Clostridium thermocellum. Two species are described, Ammoniphilus oxalaticus gen. nov., sp. nov. and Ammoniphilus oxalivorans gen. nov., sp. nov. The type strains of these species are strains RAOx-1 (= DSM 11538) and RAOx-FS (= DSM 11537), respectively. Ammoniphilus strains were isolated from the rhizosphere of sorrel (Rumex acetosa) and from decaying wood. The strains require a high concentration of ammonium ions and use oxalate as the sole organic source of carbon and energy for growth; no growth factors were required. Growth occurred at pH 6.8-9.5. The optimum temperature and pH for growth were 28-30 degrees C and 8.0-8.5. All strains grew in a saturated solution of ammonium oxalate, and tolerated 3% NaCl. Whole-cell hydrolysates contain meso-diaminopimelic acid and glucose. The menaquinone of the strains was MK 7, and the major cellular fatty acids were 12-methyl tetradecanoic, cis-hexadec-9-enoic and hexadecanoic acids. The G + C content of the DNA was 45-46 mol% for A. oxalaticus and 42 mol% for A. oxalivorans. The almost complete 16S rDNA sequence of three strains of the two species of Ammoniphilus shows that the genus falls into the radiation of the Clostridium-Bacillus subphylum of Gram-positive bacteria. The closest phylogenetic neighbour of Ammoniphilus is Oxalophagus oxalicus. The DNA-DNA hybridization value between strains RAOx-1 and RAOx-FS was 39.7%. PMID:9542085

  20. Fate of mesophilic aerobic bacteria and Salmonella enterica on the surface of eggs as affected by chicken feces, storage temperature, and relative humidity.

    PubMed

    Park, Sunhyung; Choi, Seonyeong; Kim, Hoikyung; Kim, Yoonsook; Kim, Byeong-sam; Beuchat, Larry R; Ryu, Jee-Hoon

    2015-06-01

    We compared the microbiological quality of chicken eggshells obtained from a traditional wholesale market and a modern supermarket. We also determined the survival and growth characteristics of naturally occurring mesophilic aerobic bacteria (MAB) and artificially inoculated Salmonella enterica on eggshells under various environmental conditions (presence of chicken feces, temperature [4, 12, or 25 °C], and relative humidity [RH; 43 or 85%]). The populations of MAB, coliforms, and molds and yeasts on eggshells purchased from a traditional wholesale market were significantly (P ? 0.05) higher than those from a modern supermarket. In the second study, when we stored uninoculated eggs under various storage conditions, the population of MAB on eggshells (4.7-4.9 log CFU/egg) remained constant for 21 days, regardless of storage conditions. However, when eggshells were inoculated with S. enterica and stored under the same conditions, populations of the pathogen decreased significantly (P ? 0.05) under all tested conditions. Survival of S. enterica increased significantly (P ? 0.05) in the presence of feces, at low temperatures, and at low RH. These observations will be of value when predicting the behavior of microorganisms on eggshells and selecting storage conditions that reduce the populations of S. enterica on eggshells during distribution. PMID:25791009

  1. Isolation, Characterization, and Polyaromatic Hydrocarbon Degradation Potential of Aerobic Bacteria from Marine Macrofaunal Burrow Sediments and Description of Lutibacterium anuloederans gen. nov., sp. nov., and Cycloclasticus spirillensus sp. nov

    Microsoft Academic Search

    W. K. Chung; G. M. King

    2001-01-01

    Two new polyaromatic hydrocarbon-degrading marine bacteria have been isolated from burrow wall sedi- ments of benthic macrofauna by using enrichments on phenanthrene. Strain LC8 (from a polychaete) and strain M4-6 (from a mollusc) are aerobic and gram negative and require sodium chloride (>1%) for growth. Both strains can use 2- and 3-ring polycyclic aromatic hydrocarbons as their sole carbon and

  2. Pyrosequencing vs. culture-dependent approaches to analyze lactic acid bacteria associated to chicha, a traditional maize-based fermented beverage from Northwestern Argentina.

    PubMed

    Elizaquível, Patricia; Pérez-Cataluña, Alba; Yépez, Alba; Aristimuño, Cecilia; Jiménez, Eugenia; Cocconcelli, Pier Sandro; Vignolo, Graciela; Aznar, Rosa

    2015-04-01

    The diversity of lactic acid bacteria (LAB) associated with chicha, a traditional maize-based fermented alcoholic beverage from Northwestern Argentina, was analyzed using culture-dependent and culture-independent approaches. Samples corresponding to 10 production steps were obtained from two local producers at Maimará (chicha M) and Tumbaya (chicha T). Whereas by culture-dependent approach a few number of species (Lactobacillus plantarum and Weissella viridescens in chicha M, and Enterococcus faecium and Leuconostoc mesenteroides in chicha T) were identified, a higher quantitative distribution of taxa was found in both beverages by pyrosequencing. The relative abundance of OTUs was higher in chicha M than in chicha T; six LAB genera were common for chicha M and T: Enterococcus, Lactococcus, Streptococcus, Weissella, Leuconostoc and Lactobacillus while Pediococcus only was detected in chicha M. Among the 46 identified LAB species, those of Lactobacillus were dominant in both chicha samples, exhibiting the highest diversity, whereas Enterococcus and Leuconostoc were recorded as the second dominant genera in chicha T and M, respectively. Identification at species level showed the predominance of Lb. plantarum, Lactobacillus rossiae, Leuconostoc lactis and W. viridescens in chicha M while Enterococcus hirae, E. faecium, Lc. mesenteroides and Weissella confusa predominated in chicha T samples. In parallel, when presumptive LAB isolates (chicha M: 146; chicha T: 246) recovered from the same samples were identified by ISR-PCR and RAPD-PCR profiles, species-specific PCR and 16S rRNA gene sequencing, most of them were assigned to the Leuconostoc genus (Lc. mesenteroides and Lc. lactis) in chicha M, Lactobacillus, Weissella and Enterococcus being also present. In contrast, chicha T exhibited the presence of Enterococcus and Leuconostoc, E. faecium being the most representative species. Massive sequencing approach was applied for the first time to study the diversity and evolution of microbial communities during chicha manufacture. Although differences in the LAB species profile between the two geographically different chicha productions were observed by culturing, a larger number for predominant LAB species as well as other minorities were revealed by pyrosequencing. The fine molecular inventory achieved by pyrosequencing provided more precise information on LAB population composition than culture-dependent analysis processes. PMID:25584777

  3. Fecal lactic acid bacteria increased in adolescents randomized to whole-grain but not refined-grain foods, whereas inflammatory cytokine production decreased equally with both interventions.

    PubMed

    Langkamp-Henken, Bobbi; Nieves, Carmelo; Culpepper, Tyler; Radford, Allyson; Girard, Stephanie-Anne; Hughes, Christine; Christman, Mary C; Mai, Volker; Dahl, Wendy J; Boileau, Thomas; Jonnalagadda, Satya S; Thielecke, Frank

    2012-11-01

    The intake of whole-grain (WG) foods by adolescents is reported to be approximately one-third the recommended intake of 48 g/d. This 6-wk randomized interventional study determined the effect of replacing grains within the diet with refined-grain (RG; n = 42) or WG (n = 41) foods/d on gastrointestinal and immune health in adolescents (aged 12.7 ± 0.1 y). A variety of grain-based foods were delivered weekly to participants and their families. Participants were encouraged to eat 3 different kinds of study foods (e.g., bread, cereals, snacks)/d with goals of 0 g/d (RG) and 80 g/d (WG). Stool samples were obtained during the prebaseline and final weeks to measure bifidobacteria and lactic acid bacteria (LAB) using qPCR. Stool frequency was recorded daily. Blood was drawn at baseline and at final visits for immune markers. Across groups, total-grain intake increased by one serving. The intake of WG was similar at baseline (18 ± 3 g) between groups but increased to 60 ± 5 g in the WG group and decreased to 4 ± 1 g in the RG group. Fecal bifidobacteria increased from baseline with both interventions, but LAB increased (P < 0.05) from baseline [2.4 ± 0.2 log(10) genome equivalents (eq)] to wk 6 (3.0 ± 0.2 log(10) genome eq) in the WG group but not in the RG group (baseline: 2.9 ± 0.2 log(10) genome eq; wk 6: 3.0 ± 0.1 log(10) genome eq). There was no difference in stool frequency, serum antioxidant potential, or in vitro LPS-stimulated mononuclear cell production of inflammatory cytokines between groups. However, across both groups the number of daily stools tended to increase (P = 0.08) by 0.0034 stools/g WG or by 0.2 stools with 60 g WG, mean antioxidant potential increased by 58%, and mean production of TNF-?, IL-1?, and IL-6 decreased by 24, 22, and 42%, respectively, between baseline and wk 6. Overall, incorporating either WG or RG foods increased serum antioxidant concentrations and decreased inflammatory cytokine production; however, WG study foods had more of an effect on aspects of gastrointestinal health. PMID:23014489

  4. Aerobic bacteria from mucous membranes, ear canals, and skin wounds of feral cats in Grenada, and the antimicrobial drug susceptibility of major isolates.

    PubMed

    Hariharan, Harry; Matthew, Vanessa; Fountain, Jacqueline; Snell, Alicia; Doherty, Devin; King, Brittany; Shemer, Eran; Oliveira, Simone; Sharma, Ravindra N

    2011-03-01

    In a 2-year period 54 feral cats were captured in Grenada, West Indies, and a total of 383 samples consisting of swabs from rectum, vagina, ears, eyes, mouth, nose and wounds/abscesses, were cultured for aerobic bacteria and campylobacters. A total of 251 bacterial isolates were obtained, of which 205 were identified to species level and 46 to genus level. A commercial bacterial identification system (API/Biomerieux), was used for this purpose. The most common species was Escherichia coli (N=60), followed by Staphylococcus felis/simulans (40), S. hominis (16), S. haemolyticus (12), Streptococcus canis (9), Proteus mirabilis (8), Pasteurella multocida (7), Streptococcus mitis (7), Staphylococcus xylosus (7), S. capitis (6), S. chromogenes (4), S. sciuri (3), S. auricularis (2), S. lentus (2), S. hyicus (2), Streptococcus suis (2) and Pseudomonas argentinensis (2). Sixteen other isolates were identified to species level. A molecular method using 16S rRNA sequencing was used to confirm/identify 22 isolates. Salmonella or campylobacters were not isolated from rectal swabs. E. coli and S. felis/simulans together constituted 50% of isolates from vagina. S. felis/simulans was the most common species from culture positive ear and eye samples. P. multocida was isolated from 15% of mouth samples. Coagulase-negative staphylococci were the most common isolates from nose and wound swabs. Staphylococcus aureus, or S. intemedius/S. pseudintermedius were not isolated from any sample. Antimicrobial drug resistance was minimal, most isolates being susceptible to all drugs tested against, including tetracycline. PMID:20627391

  5. Lactic acidaemia

    Microsoft Academic Search

    B. H. Robinson; W. G. Sherwood

    1984-01-01

    Congenital childhood lactic acidaemia is a poorly understood group of genetic diseases. The most common underlying inherited\\u000a defect encountered in this group is deficiency of the pyruvate dehydrogenase complex. Of 23 cases we have diagnosed, 18 have\\u000a a deficiency in the first component of the complex, the E1 decarboxylase, while the other five have multiple?-keto acid dehydrogenase deficiency due to

  6. Contamination flows of Bacillus cereus and spore-forming aerobic bacteria in a cooked, pasteurized and chilled zucchini purée processing line.

    PubMed

    Guinebretiere, M H; Girardin, H; Dargaignaratz, C; Carlin, F; Nguyen-The, C

    2003-05-15

    A food processing plant producing pasteurized purées and its zucchini purée processing line were examined for contamination with aerobic and facultative anaerobic bacterial spores during a day's operation. Multiplication of spores was also monitored in the product stored under different conditions. High concentrations of Bacillus cereus spores were found in the soil in which the zucchinis were grown (4.6+/-0.3 log CFU/g), with a background spore population of 6.1+/-0.2 log CFU/g. In the processing plant, no B. cereus or psychrotrophic bacterial spores were detected on equipment. B. cereus and psychrotrophic bacterial spores were detected after enrichment in all samples of raw zucchinis, washed zucchinis, of two ingredients (starch and milk proteins) and in processed purée at each processing step. Steam cooking of raw zucchinis and pasteurization of purée in the final package significantly reduced spore numbers to 0.5+/-0.3 log CFU/g in the processed food. During storage, numbers of spore-forming bacteria increased up to 7.8+/-0.1 log CFU/g in purée after 5 days at 20-25 degrees C, 7.5+/-0.3 log CFU/g after 21 days at 10 degrees C and 3.8+/-1.1 log CFU/g after 21 days at 4 degrees C. B. cereus counts reached 6.4+/-0.5 log CFU/g at 20-25 degrees C, 4.6+/-1.9 log CFU/g at 10 degrees C, and remained below the detection threshold (1.7 log CFU/g) at 4 degrees C. Our findings indicate that raw vegetables and texturing agents such as milk proteins and starch, in spite of their low levels of contamination with bacterial spores and the heat treatments they undergo, may significantly contribute to the final contamination of cooked chilled foods. This contamination resulted in growth of B. cereus and psychrotrophic bacterial spores during storage of vegetable purée. Ways to eliminate such contamination in the processing line are discussed. PMID:12593925

  7. Catalase Overexpression Reduces Lactic Acid-Induced Oxidative Stress in Saccharomyces cerevisiae?

    PubMed Central

    Abbott, Derek A.; Suir, Erwin; Duong, Giang-Huong; de Hulster, Erik; Pronk, Jack T.; van Maris, Antonius J. A.

    2009-01-01

    Industrial production of lactic acid with the current pyruvate decarboxylase-negative Saccharomyces cerevisiae strains requires aeration to allow for respiratory generation of ATP to facilitate growth and, even under nongrowing conditions, cellular maintenance. In the current study, we observed an inhibition of aerobic growth in the presence of lactic acid. Unexpectedly, the cyb2? reference strain, used to avoid aerobic consumption of lactic acid, had a specific growth rate of 0.25 h?1 in anaerobic batch cultures containing lactic acid but only 0.16 h?1 in identical aerobic cultures. Measurements of aerobic cultures of S. cerevisiae showed that the addition of lactic acid to the growth medium resulted in elevated levels of reactive oxygen species (ROS). To reduce the accumulation of lactic acid-induced ROS, cytosolic catalase (CTT1) was overexpressed by replacing the native promoter with the strong constitutive TPI1 promoter. Increased activity of catalase was confirmed and later correlated with decreased levels of ROS and increased specific growth rates in the presence of high lactic acid concentrations. The increased fitness of this genetically modified strain demonstrates the successful attenuation of additional stress that is derived from aerobic metabolism and may provide the basis for enhanced (micro)aerobic production of organic acids in S. cerevisiae. PMID:19251894

  8. Lactic acid production in exercising horses fed N,N-dimethylglycine 

    E-print Network

    Moffitt, Patricia Ghagan

    1984-01-01

    aerobic conditions. The same biological explanations can be made for these reduced levels as were proposed for improved conditioning. The muscles may be conducting higher levels of aerobic glycolysis with consequently lowered production of lactic acid... LACTIC ACID PRODUCTION IN EXERCISING HORSES FED N, N-DIMETHYLGLYCINE A Thesis by PATRICIA GHAGAN MOFFITT Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER...

  9. (Per)Chlorate-Reducing Bacteria Can Utilize Aerobic and Anaerobic Pathways of Aromatic Degradation with (Per)Chlorate as an Electron Acceptor

    PubMed Central

    Carlström, Charlotte I.; Loutey, Dana; Bauer, Stefan; Clark, Iain C.; Rohde, Robert A.; Iavarone, Anthony T.; Lucas, Lauren

    2015-01-01

    ABSTRACT The pathways involved in aromatic compound oxidation under perchlorate and chlorate [collectively known as (per)chlorate]-reducing conditions are poorly understood. Previous studies suggest that these are oxygenase-dependent pathways involving O2 biogenically produced during (per)chlorate respiration. Recently, we described Sedimenticola selenatireducens CUZ and Dechloromarinus chlorophilus NSS, which oxidized phenylacetate and benzoate, two key intermediates in aromatic compound catabolism, coupled to the reduction of perchlorate or chlorate, respectively, and nitrate. While strain CUZ also oxidized benzoate and phenylacetate with oxygen as an electron acceptor, strain NSS oxidized only the latter, even at a very low oxygen concentration (1%, vol/vol). Strains CUZ and NSS contain similar genes for both the anaerobic and aerobic-hybrid pathways of benzoate and phenylacetate degradation; however, the key genes (paaABCD) encoding the epoxidase of the aerobic-hybrid phenylacetate pathway were not found in either genome. By using transcriptomics and proteomics, as well as by monitoring metabolic intermediates, we investigated the utilization of the anaerobic and aerobic-hybrid pathways on different electron acceptors. For strain CUZ, the results indicated utilization of the anaerobic pathways with perchlorate and nitrate as electron acceptors and of the aerobic-hybrid pathways in the presence of oxygen. In contrast, proteomic results suggest that strain NSS may use a combination of the anaerobic and aerobic-hybrid pathways when growing on phenylacetate with chlorate. Though microbial (per)chlorate reduction produces molecular oxygen through the dismutation of chlorite (ClO2?), this study demonstrates that anaerobic pathways for the degradation of aromatics can still be utilized by these novel organisms. PMID:25805732

  10. Survival of Aerobic and Anaerobic Bacteria in Purulent Clinical Specimens Maintained in the Copan Venturi Transystem and Becton Dickinson Port-a-Cul Transport Systems

    Microsoft Academic Search

    DIANE M. CITRON; YUMI A. WARREN; MARIE K. HUDSPETH; ELLIE J. C. GOLDSTEIN

    2000-01-01

    Protection of anaerobic bacteria from exposure to oxygen during the transport of clinical specimens to the laboratory is crucial for the survival of these organisms. Because the use of swabs may encourage collection of superficial specimens that represent colonizing bacteria instead of the etiologic agents found deeper in the infected tissues, aspirates have always been preferable to swab systems for

  11. Aerobic Gram-Positive and Gram-Negative Bacteria Exhibit Differential Sensitivity to and Transformation of 2,4,6Trinitrotoluene (TNT)

    Microsoft Academic Search

    Mark E. Fuller

    1997-01-01

    .   A systematic evaluation of the ability of different bacterial genera to transform 2,4,6-trinitrotoluene (TNT), and grow in\\u000a its presence, was conducted. Aerobic Gram-negative organisms degraded TNT and evidenced net consumption of reduced metabolites\\u000a when cultured in molasses medium. Some Gram-negative isolates transformed all the initial TNT to undetectable metabolites,\\u000a with no adsorption of TNT or metabolites to cells. Growth

  12. Spoilage potential of psychrotrophic lactic acid bacteria (LAB) species: Leuconostoc gelidum subsp. gasicomitatum and Lactococcus piscium, on sweet bell pepper (SBP) simulation medium under different gas compositions.

    PubMed

    Pothakos, Vasileios; Nyambi, Clarice; Zhang, Bao-Yu; Papastergiadis, Antonios; De Meulenaer, Bruno; Devlieghere, Frank

    2014-05-16

    Sweet bell peppers are a significant constituent of retail, chilled-stored and packaged food products like fresh salads, marinades and ready-to-eat (RTE) meals. Previously, through general screening of the Belgian market and by means of source tracking analysis in a plant manufacturing minimally processed, vegetable salads the susceptibility of fresh-cut sweet bell peppers to lactic acid bacterium (LAB) contamination was substantiated. The determination of the metabolic profiles of Leuconostoc gelidum subsp. gasicomitatum and Lactococcus piscium, two major psychrotrophic, spoilage-related LAB species, on sweet bell pepper (SBP) simulation medium under different packaging conditions - 1.) vacuum: 100% N2, 2.) air: 21% O2, 79% N2, 3.) MAP1: 30% CO2, 70% N2 and 4.) MAP2: 50% O2, 50% CO2 - facilitated a better understanding of the spoilage potential of these microbes as well as the presumptive contribution of O2 in the spectrum of produced volatile organic compounds (VOCs) associated with poor organoleptic properties of food products. Generally, none of the applied gas compositions inhibited the growth of the 4 L. gelidum subsp. gasicomitatum isolates, however the presence of O2 resulted in buttery off-odors by inducing primarily the accumulation of diacetyl and pungent "vinegar" smell due to acetic acid. The 3 tested isolates of L. piscium varied greatly among their growth dynamics and inhibition at MAP2. They exhibited either weak spoilage profile or very offensive metabolism confirming significant intraspecies diversity. PMID:24690877

  13. Anti-Amnesic Effect of Fermented Ganoderma lucidum Water Extracts by Lactic Acid Bacteria on Scopolamine-Induced Memory Impairment in Rats

    PubMed Central

    Choi, Yu Jin; Yang, Hee Sun; Jo, Jun Hee; Lee, Sang Cheon; Park, Tae Young; Choi, Bong Suk; Seo, Kyoung Sun; Huh, Chang Ki

    2015-01-01

    This study investigated the anti-amnesic effect of fermented Ganoderma lucidum water extracts (GW) on scopolamine-induced memory impairment in rats. GW were fermented by the lactic acid bacterium Bifidobacterium bifidum (FGWB), followed by Lactobacillus sakei LI033 (FGWBL). To induce amnesia, scopolamine (1 mg/kg) was intraperitoneally injected into rats 30 min before the behavioral tests. Step-through latencies of rats treated with primary fermented extracts (300 mg/kg, FGWB) and secondary fermented extracts (300 mg/kg, FGWBL) were significantly longer than those of rats treated with GW (300 mg/kg) in the retention trial of the multiple trial passive avoidance test. In the Morris water maze task, FGWBL significantly shortened escape latencies in training trials. Furthermore, swimming times within the target zone during the probe trial with FGWBL were significantly higher than the GW and FGWB treatments. In addition, acetylcholinesterase activities were lower in the brains of scopolamine-treated rats treated with FGWBL. These results suggest that FGWBL could be useful to enhance learning memory and cognitive function via cholinergic dysfunction. PMID:26176000

  14. Influence of autochthonous lactic acid bacteria and enzymatic yeast extracts on the microbiological, biochemical and sensorial properties of Lben generic products.

    PubMed

    Mangia, Nicoletta P; Garau, Giovanni; Murgia, Marco A; Bennani, Abdelmajid; Deiana, Pietrino

    2014-05-01

    In this study we identified Lactococcus lactis subsp. lactis, Lc. lactis subsp. lactis biovar diacetylactis, Kluyveromices lactis and Saccharomyces cerevisiae as the dominant microorganisms of traditional Moroccan acid-alcoholic fermented milk named Lben. The low pH (3·8±0·3), lactose (16·8±3·4 mg/l) and lactic acid (8·16±0·6 mg/l) content indicated that a strong fermentation occurred in the traditional product which was also characterised by the substantial presence of ethanol and typical volatile carbonyl compounds (i.e., acetoin, diacetyl and acetaldehyde). Microbiological analyses of experimental Lben manufactured with selected strains (isolated from the traditional product) of Lc. lactis subsp. lactis and Lc. lactis subsp. lactis biovar. diacetylactis alone (batch A) and in combination with enzymatic extract of a K. lactis strain (batch B) indicated a good effectiveness of the starters employed (?1010 CFU/g of lactococci after 8 h of incubation) and a significant effect of the yeast enzyme extract on lactococci viability. Despite slight changes in the physicochemical characteristics of the two Lben during the 15 d storage period, volatile compounds (i.e. ethanol, acetaldehyde, diacetyl and acetoin) were consistently higher in batch B. Moreover, sensorial analysis performed after 15 d of storage, highlighted higher odour and flavour intensity, vegetable odour and viscosity in batch B while batch A displayed higher astringency. PMID:24642233

  15. Improved Enumeration of Lactic Acid Bacteria in Mesophilic Dairy Starter Cultures by Using Multiplex Quantitative Real-Time PCR and Flow Cytometry-Fluorescence In Situ Hybridization

    Microsoft Academic Search

    Udo Friedrich; Jan Lenke

    2006-01-01

    Nucleic acid-based assays were developed to enumerate members of the three taxa Lactococcus lactis subsp. cremoris, L. lactis subsp. lactis, and Leuconostoc spp. in mesophilic starter cultures. To our knowledge the present is the first study to present a multiplex quantitative PCR (qPCR) strategy for the relative enumeration of bacteria. The multiplex qPCR strategy was designed to quantify the target

  16. Utilisation of galacto-oligosaccharides as selective substrates for growth by lactic acid bacteria including Bifidobacterium lactis DR10 and Lactobacillus rhamnosus DR20

    Microsoft Academic Search

    Pramod K Gopal; Patrick A Sullivan; John B Smart

    2001-01-01

    Two probiotic strains of bacteria Bifidobacterium lactis DR10 and Lactobacillus rhamnosus DR20 were tested for their ability to utilise and grow on galacto-oligosaccharides present in a commercial hydrolysed lactose milk powder. The results clearly demonstrated that B. lactis DR10 preferentially utilises tri- and tetra-saccharides whereas Lb. rhamnosus DR20 prefers sugars with a lower degree of polymerisation, i.e., disaccharides and monosaccharides.

  17. Lactic acid test

    MedlinePLUS

    Lactate test ... test. Exercise can cause a temporary increase in lactic acid levels. ... not getting enough oxygen. Conditions that can increase lactic acid levels include: Heart failure Liver disease Lung disease ...

  18. Evaluation of the Use of PCR and Reverse Transcriptase PCR for Detection of Pathogenic Bacteria in Biosolids from Anaerobic Digestors and Aerobic Composters

    Microsoft Academic Search

    Carola Burtscher; Stefan Wuertz

    2003-01-01

    A PCR-based method and a reverse transcriptase PCR (RT-PCR)-based method were developed for the detection of pathogenic bacteria in organic waste, using Salmonella spp., Listeria monocytogenes, Yersinia enterocolitica, and Staphylococcus aureus as model organisms. In seeded organic waste samples, detection limits of less than 10 cells per g of organic waste were achieved after one-step enrichment of bacteria, isolation, and

  19. Solution structure of carnobacteriocin B2 and implications for structure-activity relationships among type IIa bacteriocins from lactic acid bacteria.

    PubMed

    Wang, Y; Henz, M E; Gallagher, N L; Chai, S; Gibbs, A C; Yan, L Z; Stiles, M E; Wishart, D S; Vederas, J C

    1999-11-23

    Carnobacteriocin B2 (CbnB2), a type IIa bacteriocin, is a 48 residue antimicrobial peptide from the lactic acid bacterium Carnobacterium pisicola LV17B. Type IIa bacteriocins have a conserved YGNGVXC sequence near the N-terminus and usually contain a disulfide bridge. CbnB2 seemed to be unique in that its two cysteines (Cys9 and Cys14) could be isolated as free thiols [Quadri et al. (1994) J. Biol. Chem. 26, 12204-12211]. To establish the structural consequences of the presence or absence of a disulfide bridge and to investigate if the YGNGVXC sequence is a receptor-binding motif [Fleury et al. (1996) J. Biol. Chem. 271, 14421-14429], the three-dimensional solution structure of CbnB2 was determined by two-dimensional (1)H nuclear magnetic resonance (NMR) techniques. Mass spectroscopic and thiol modification experiments on CbnB2 and on model peptides, in conjunction with activity measurements, were used to verify the redox status of CbnB2. The results show that CbnB2 readily forms a disulfide bond and that this peptide has full antimicrobial activity. NMR results indicate that CbnB2 in trifluoroethanol (TFE) has a well-defined central helical structure (residues 18-39) but a disordered N terminus. Comparison of the CbnB2 structure with the refined solution structure of leucocin A (LeuA), another type IIa bacteriocin, indicates that the central helical structure is conserved between the two peptides despite differences in sequence but that the N-terminal structure (a proposed receptor binding site) is not. This is unexpected because LeuA and CbnB2 exhibit >66% sequence identity in the first 24 residues. This suggests that the N-terminus, which had been proposed [Fleury et al. (1996) J. Biol. Chem. 271, 14421-14429] to be a receptor binding site of type IIa bacteriocins, may not be directly involved and that recognition of the amphiphilic helical portion is the critical feature. PMID:10569926

  20. Identification of lactic acid bacteria isolated from kimchi and studies on their suitability for application as starter culture in the production of fermented sausages.

    PubMed

    Lee, Joo-Yeon; Kim, Cheon-Jei; Kunz, Benno

    2006-03-01

    The aim of the investigation was to identify strains of lactobacilli coming from kimchi with properties suitable for use as starter cultures in sausage fermentation. A total of 31 strains of lactobacilli were isolated from kimchi on the 4-6th day of fermentation at 20°C using MRS agar plates and identified on the basis of morphological, biochemical, and physiological characteristics. The isolates were identified as Leuconostoc mes.mes./dent (12.9%), Lactobacillus curvatus (9.7%), Lactobacillus brevis (35.5%), Lactobacillus sake (25.8%), and Lactobacillus plantarum (16.1%). Thus, 51.6% of the isolates were homo-fermentative or facultative hetero-fermentative bacteria and the rest (48.4%) were hetero-fermentative bacteria. Among them L. brevis, L. curvatus, L. plantarum, and L. sake were investigated for their growth profile and metabolism characteristics in the fluid (submerged) model-medium modified according to the special conditions of fermented sausages. Relatively good growth properties were found for L. brevis, L. plantarum, and L. sake with maximum numbers of 8.18, 8.51 and 8.17cfu/ml, respectively, whereas L. curvatus could not adapt to the special environmental conditions. Regarding souring properties, L. brevis showed little ability to decrease pH, whereas L. curvatus, L. plantarum, and L. sake showed relatively good acidifying properties. According to the results of glucose fermentation and its products, only L. plantarum exhibited homo-fermentative characteristics. As a result only L. plantarum among the isolates from kimchi had an ability to adapt to the complex environment of fermented sausage, which will thereby allow them to act as starter cultures and natural preservatives in sausage production. PMID:22061727

  1. Influence of food colorant and initial COD concentration on the efficiencies of micro-aerobic sequencing batch reactor (micro-aerobic SBR) for casein recovery under non-sterile condition by Lactobacillus casei TISTR 1500.

    PubMed

    Seesuriyachan, Phisit; Chaiyaso, Thanongsak; Sasaki, Ken; Techapun, Charin

    2009-09-01

    The acid biocoagulants produced from non-sterile lactic acid fermentation by Lactobacillus casei TISTR 1500 were used to settle colloidal protein, mainly casein, at the isoelectric point in dairy effluent prior to secondary treatment. High concentration of azo dye (Ponceau 4R) in the dairy wastewater and the stress of starvation decreased the efficiencies of the micro-aerobic SBR. Consequently, low casein recovery obtained and organic removal suffered a decline. The number of lactic acid bacteria (LAB) also declined from log 7.4 to log 5.30 in the system fed with 400 mg L(-1) of the dye containing wastewater. The recovery of the system, however, showed that 25,000 mg COD L(-1) influent with 200 mg L(-1) of the dye maintained the growth of LAB in the range of log 7.74-8.12, with lactic and acetic production (2597 and 197 mg L(-1)) and 83% protein removal. The results in this study suggested that the inhibitory effects were compensated with high organic content feeding. PMID:19423333

  2. Protective effect of a mixture of kefir-isolated lactic acid bacteria and yeasts in a hamster model of Clostridium difficile infection.

    PubMed

    Bolla, Patricia A; Carasi, Paula; Bolla, María de los Angeles; De Antoni, Graciela L; Serradell, María de los Angeles

    2013-06-01

    The objective of this work was to test the protective effect of a mixture (MM) constituted by kefir-isolated microorganisms (Lactobacillus plantarum, Lactobacillus kefir, Lc. lactis, Kluyveromyces marxianus and Saccharomyces cerevisiae) in a hamster model of infection with Clostridium difficile, an anaerobic Gram-positive bacterium that causes diarrhoea. Placebo or MM was administered ad libitum in drinking water from day 0 to the end of treatment. Hamsters received orally 200 ?g of clyndamicin at day 7 and then were infected with 1 × 10(8) CFU of C. difficile by gavage. Development of diarrhoea and death was registered until the end of the protocol. Surviving animals were sacrificed at day 16, and a test for biological activity of clostridial toxins and histological stainings were performed in caecum samples. Six of seven infected animals developed diarrhoea and 5/7 died at the end of the experimental protocol. The histological sections showed oedema and inflammatory infiltrates with neutrophils and crypt abscesses. In the group of animals infected and treated with MM1/1000, only 1 of 7 hamsters showed diarrhoea and none of them died. The histological sections showed only a slight thickening of the mucosa with presence of lymphocytic infiltrate. These results demonstrate that an oral treatment with a mixture of kefir-isolated bacteria and yeasts was able to prevent diarrhoea and enterocolitis triggered by C. difficile. PMID:23542116

  3. Nucleotide sequence, structural organization and host range of pRS4, a small cryptic Pediococcus pentosaceus plasmid that contains two cassettes commonly found in other lactic acid bacteria.

    PubMed

    Alegre, M Teresa; Rodríguez, M Carmen; Mesas, Juan M

    2005-09-01

    The complete nucleotide sequence of the cryptic plasmid pRS4 (3550 bp) from Pediococcus pentosaceus RS4 was determined. Sequence analysis revealed the presence of three open reading frames (ORFs). The putative protein coded by ORF 1 showed 93% identity with the mobilization protein of Lactobacillus casei plasmid pLC88 and 94% identity with a sequenced fragment of the mobilization protein of P. damnosus plasmid pF8801, suggesting a common origin for these three mobilization proteins. The putative protein coded by ORF 2 showed 92% identity with the replication protein of L. plantarum plasmid pWCFS101, a plasmid that replicates via the rolling circle (RC) mechanism, suggesting a similar replication mechanism for pRS4. Supporting this hypothesis, a putative double strand origin (dso) and a region with palindromic sequences that could function as single strand origin (sso), were detected in pRS4. A function could not be assigned to ORF 3. Since ORF 1 exhibits high identity with L. casei plasmid pLC88 but lower identity (58%) with other Lactobacillus plasmids, and ORF 2 exhibits high identity with the L. plantarum plasmid pWCFS101 but lower identity (55-58%) with other Lactobacillus plasmids (including pLC88), two independent cassettes, from different sources, seem to be involved in the structure of pRS4. Plasmids derived from pRS4 containing the chloramphenicol resistance gene were successfully electrotransformed in L. plantarum, L. casei, P. pentosaceus, and Pediococcus acidilactici, suggesting that pRS4 could be used as a cloning vector for lactic acid bacteria. To our knowledge pRS4 is the first RC-replicating plasmid of P. pentosaceus that has been completely sequenced and used as cloning vector. PMID:16054305

  4. Isolation and characterization of heterotrophic bacteria able to grow aerobically with quaternary ammonium alcohols as sole source of carbon and nitrogen.

    PubMed

    Kaech, Andres; Vallotton, Nathalie; Egli, Thomas

    2005-04-01

    The quaternary ammonium alcohols (QAAs) 2,3-dihydroxypropyl-trimethyl-ammonium (TM), dimethyl-diethanol-ammonium (DM) and methyl-triethanol-ammonium (MM) are hydrolysis products of their parent esterquat surfactants, which are widely used as softeners in fabric care. We isolated several bacteria growing with QAAs as the sole source of carbon and nitrogen. The strains were compared with a previously isolated TM-degrading bacterium, which was identified as a representative of the species Pseudomonas putida (Syst. Appl. Microbiol. 24 (2001) 252). Two bacteria were isolated with DM, referred to as strains DM 1 and DM 2, respectively. Based on 16S-rDNA analysis, they provided 97% (DM 1) and 98% (DM 2) identities to the closest related strain Zoogloea ramigera Itzigsohn 1868AL. Both strains were long, slim, motile rods but only DM 1 showed the floc forming activity, which is typical for representatives of the genus Zoogloea. Using MM we isolated a Gram-negative, non-motile rod referred to as strain MM 1. The 16S-rDNA sequence of the isolated bacterium revealed 94% identities (best match) to Rhodobacter sphaeroides only. The strains MM 1 and DM 1 exclusively grew with the QAA which was used for their isolation. DM 2 was also utilizing TM as sole source of carbon and nitrogen. However, all of the isolated bacteria were growing with the natural and structurally related compound choline. PMID:15900970

  5. Methylobacterium nodulans sp. nov., for a group of aerobic, facultatively methylotrophic, legume root-nodule-forming and nitrogen-fixing bacteria.

    PubMed

    Jourand, Philippe; Giraud, Eric; Béna, Gilles; Sy, Abdoulaye; Willems, Anne; Gillis, Monique; Dreyfus, Bernard; de Lajudie, Philippe

    2004-11-01

    Data on 72 non-pigmented bacterial strains that specifically induce nitrogen-fixing root nodules on the legume species Crotalaria glaucoides, Crotalaria perrottetii and Crotalaria podocarpa are reviewed. By SDS-PAGE analysis of total protein patterns and by 16S rRNA PCR-RFLP, these strains form a homogeneous group that is separate from other legume root-nodule-forming bacteria. The 16S rRNA gene-based phylogeny indicates that these bacteria belong to the genus Methylobacterium. They can grow on C(1) compounds such as methanol, formate and formaldehyde but not methylamine as sole carbon source, and carry an mxaF gene, encoding methanol dehydrogenase, which supports their methylotrophic metabolism. Presence of a nodA nodulation gene, and ability to nodulate plants of Crotalaria species and to fix nitrogen are features that separate the strains currently included in this group from other members of the genus Methylobacterium. The present study includes additional genotypic and phenotypic characterization of this novel Methylobacterium species, i.e. nifH gene sequence, morphology, physiology, enzymic and carbon source assimilation tests and antibiotic resistance. The name Methylobacterium nodulans sp. nov. (type strain, ORS 2060(T)=CNCM I 2342(T)=LMG 21967(T)) is proposed for this group of root-nodule-forming bacteria. PMID:15545469

  6. Phylogenetic positions of novel aerobic, bacteriochlorophyll a-containing bacteria and description of Roseococcus thiosulfatophilus gen. nov., sp. nov., Erythromicrobium ramosum gen. nov., sp. nov., and Erythrobacter litoralis sp. nov.

    PubMed

    Yurkov, V; Stackebrandt, E; Holmes, A; Fuerst, J A; Hugenholtz, P; Golecki, J; Gad'on, N; Gorlenko, V M; Kompantseva, E I; Drews, G

    1994-07-01

    We analyzed the 16S ribosomal DNAs of three obligately aerobic, bacteriochlorophyll a-containing bacteria, "Roseococcus thiosulfatophilus," "Erythromicrobium ramosum," and new isolate T4T (T = type strain), which was obtained from a marine cyanobacterial mat. "Roseococcus thiosulfatophilus" is a member of the alpha-1 subclass of the Proteobacteria and is moderately related to Rhodopila globiformis, Thiobacillus acidophilus, and Acidiphilium cryptum (level of sequence similarity, 90%). "Erythromicrobium ramosum" and isolate T4T are closely related to Erythrobacter longus and Porphyrobacter neustonensis (level of sequence similarity, 95%). These organisms are members of the alpha-4 subclass of the Proteobacteria. Strain T4T is a motile, red or orange bacterium. The major carotenoids are bacteriorubixanthinal and erythroxanthin sulfate. In vivo measurements revealed bacteriochlorophyll absorption maxima at 377, 590, 800, and 868 nm. Strain T4T grows in the presence of 5 to 96/1000 salinity and uses glucose, fructose, acetate, pyruvate, glutamate, succinate, and lactate as substrates. On the basis of its distinct phylogenetic position and phenotypic characteristics which are different from those of Erythrobacter longus, we propose that strain T4T should be placed in a new species of the genus Erythrobacter, Erythrobacter litoralis. The descriptions of "Roseococcus thiosulfatophilus" and "Erythromicrobium ramosum" are emended. PMID:7520734

  7. Summary report on the aerobic degradation of diesel fuel and the degradation of toluene under aerobic, denitrifying and sulfate reducing conditions

    SciTech Connect

    Coyne, P.; Smith, G. [New Mexico State Univ., Las Cruces, NM (United States)

    1995-08-15

    This report contains a number of studies that were performed to better understand the technology of the biodegradation of petroleum hydrocarbons. Topics of investigation include the following: diesel fuel degradation by Rhodococcus erythropolis; BTEX degradation by soil isolates; aerobic degradation of diesel fuel-respirometry; aerobic degradation of diesel fuel-shake culture; aerobic toluene degradation by A3; effect of HEPES, B1, and myo-inositol addition on the growth of A3; aerobic and anaerobic toluene degradation by contaminated soils; denitrifying bacteria MPNs; sulfate-reducing bacteria MPNs; and aerobic, DNB and SRB enrichments.

  8. Natural hot spots for gain of multiple resistances: arsenic and antibiotic resistances in heterotrophic, aerobic bacteria from marine hydrothermal vent fields.

    PubMed

    Farias, Pedro; Espírito Santo, Christophe; Branco, Rita; Francisco, Romeu; Santos, Susana; Hansen, Lars; Sorensen, Soren; Morais, Paula V

    2015-04-01

    Microorganisms are responsible for multiple antibiotic resistances that have been associated with resistance/tolerance to heavy metals, with consequences to public health. Many genes conferring these resistances are located on mobile genetic elements, easily exchanged among phylogenetically distant bacteria. The objective of the present work was to isolate arsenic-, antimonite-, and antibiotic-resistant strains and to determine the existence of plasmids harboring antibiotic/arsenic/antimonite resistance traits in phenotypically resistant strains, in a nonanthropogenically impacted environment. The hydrothermal Lucky Strike field in the Azores archipelago (North Atlantic, between 11°N and 38°N), at the Mid-Atlantic Ridge, protected under the OSPAR Convention, was sampled as a metal-rich pristine environment. A total of 35 strains from 8 different species were isolated in the presence of arsenate, arsenite, and antimonite. ACR3 and arsB genes were amplified from the sediment's total DNA, and 4 isolates also carried ACR3 genes. Phenotypic multiple resistances were found in all strains, and 7 strains had recoverable plasmids. Purified plasmids were sequenced by Illumina and assembled by EDENA V3, and contig annotation was performed using the "Rapid Annotation using the Subsystems Technology" server. Determinants of resistance to copper, zinc, cadmium, cobalt, and chromium as well as to the antibiotics ?-lactams and fluoroquinolones were found in the 3 sequenced plasmids. Genes coding for heavy metal resistance and antibiotic resistance in the same mobile element were found, suggesting the possibility of horizontal gene transfer and distribution of theses resistances in the bacterial population. PMID:25636836

  9. Adaptation of lactic acid bacteria to butanol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Butanol can be produced biologically through fermentation of various substrates by Gram-positive Clostridium species. However, to profitably produce butanol at industrial scales, new microbial biocatalysts with increased tolerance to butanol are needed. In this study we report the isolation and se...

  10. Degradation of TCE using sequential anaerobic biofilm and aerobic immobilized bed reactor

    Microsoft Academic Search

    Kirit D. Chapatwala; G. R. V. Babu; Larry Baresi; Richard M. Trunzo

    1995-01-01

    Bacteria capable of degrading trichloroethylene (TCE) were isolated from contaminated wastewaters and soil sites. The aerobic cultures were identified as Pseudomonas aeruginosa (four species) and Pseudomonas fluorescens. The optimal conditions for the growth of aerobic cultures were determined. The minimal inhibitory concentration values of TCE for Pseudomonas sps. were also determined. The aerobic cells were immobilized in calcium alginate in

  11. Lactic acid from apple pomace: a laboratory experiment for teaching valorisation of wastes

    Microsoft Academic Search

    J. L. Alonso; G. Garrote; H. Domínguez; V. Santos; J. C. Parajó

    2009-01-01

    Reutilisation and valorisation of wastes and byproducts is an increasingly important topic which can be illustrated at graduate or undergraduate level by the one-step bioconversion of apple pomace (AP) (an industrial byproduct) into lactic acid. A simple operational procedure that can be carried out without sophisticated equipment is proposed: starting from AP, hydrolytic enzymes and lactic acid bacteria present in

  12. Teaching Aerobic Fitness Concepts.

    ERIC Educational Resources Information Center

    Sander, Allan N.; Ratliffe, Tom

    2002-01-01

    Discusses how to teach aerobic fitness concepts to elementary students. Some of the K-2 activities include location, size, and purpose of the heart and lungs; the exercise pulse; respiration rate; and activities to measure aerobic endurance. Some of the 3-6 activities include: definition of aerobic endurance; heart disease risk factors;…

  13. Lactic acid fermentation of cassava dough into agbelima.

    PubMed

    Amoa-Awua, W K; Appoh, F E; Jakobsen, M

    1996-08-01

    The souring of cassava dough during fermentation into the fermented cassava meal, agbelima, was investigated. Four different types of traditional inocula were used to ferment the dough and increases in titrable acidity expressed as lactic acid from 0.31-0.38 to 0.78-0.91% (w/w) confirmed the fermentation to be a process of acidification. The microflora of all inocula and fermenting dough contained high counts of lactic acid bacteria, 10(8)-10(9) cfu/g in all inocula and 10(7)-10(8), 10(8)-10(9) and 10(9) cfu/g at 0, 24 and 48 h in all fermentations. Lactobacillus plantarum was the dominant species of lactic acid bacteria during all types of fermentation accounting for 51% of 171 representative isolates taken from various stages of fermentation. Other major lactic acid bacteria found were Lactobacillus brevis, 16%, Leuconostoc mesenteroides, 15% and some cocci including Streptococcus spp. whose numbers decreased with fermentation time. The lactic acid bacteria were responsible for the souring of agbelima through the production of lactic acid. All L. plantarum, L. brevis and L. mesenteroides isolates examined demonstrated linamarase as well as other enzymatic activities but did not possess tissue degrading enzymes like cellulase, pectin esterase and polygalacturonase. The aroma profile of agbelima did not vary with the type of inoculum used and in all samples the build-up of aroma compounds were dominated by a non-identified low molecular weight alcohol, 1-propanol, isoamyl alcohol, ethyl acetate, 3-methyl-1-butanol and acetoin. Substantial reductions occurred in the levels of cyanogenic compounds present in cassava during fermentation into agbelima and detoxification was enhanced by the use of inoculum. PMID:8880299

  14. Lactic acid production by mixed cultures of Kluyveromyces marxianus, Lactobacillus delbrueckii ssp. bulgaricus and Lactobacillus helveticus.

    PubMed

    Plessas, S; Bosnea, L; Psarianos, C; Koutinas, A A; Marchant, R; Banat, I M

    2008-09-01

    Lactic acid production using Kluyveromyces marxianus (IFO 288), Lactobacillus delbrueckii ssp. bulgaricus (ATCC 11842) and Lactobacillus helveticus (ATCC 15009) individually or as mixed culture on cheese whey in stirred or static fermentation conditions was evaluated. Lactic acid production, residual sugar and cell biomass were the main features examined. Increased lactic acid production was observed, when mixed cultures were used in comparison to individual ones. The highest lactic acid concentrations were achieved when K. marxianus yeast was combined with L. delbrueckii ssp. bulgaricus, and when all the strains were used revealing possible synergistic effects between the yeast and the two lactic acid bacteria. The same synergistic effects were further observed and verified when the mixed cultures were applied in sourdough fermentations, proving that the above microbiological system could be applied in the food fermentations where high lactic acid production is sought. PMID:18155517

  15. Bacteria, toxins, and the peritoneum

    Microsoft Academic Search

    Toni Hau

    1990-01-01

    Intraperitoneal infections are caused by members of the gastrointestinal flora, mainlyEscherichia coli, enterococci, Klebsiella, Enterobacter, Proteus, Bacteroides, anaerobic cocci, Clostridia, and Fusobacteria. The Gram-negative aerobic bacteria exert their pathogenic potential mainly through endotoxin which acts by way of mediators, causing systemic septic response and, initially, the local response of the peritoneal cavity. The main virulence factors of anaerobic bacteria are

  16. Ultrastructure of bacteria and the proportion of Gram-negative bacteria in marine sediments

    Microsoft Academic Search

    D. J. W. Moriarty; A. C. Hayward

    1982-01-01

    Bacteria in sediments from the surface aerobic layer (0–1 cm) and a deeper anaerobic layer (20–21 cm) of a seagrass bed were examined in section by transmission electron microscopy. Bacteria with a Gram-negative ultrastructure made up 90% of bacteria in the surface layer, and Gram-positive bacteria comprised 10%. In the anaerobic zone, Gram-negative bacteria comprised 70% and Gram-positive bacteria 30%

  17. Quantification of the Antimicrobial Substances Produced by Lactic Acid Bacteria used as an Intervention to Inhibit Escherichia coli O157:H7 and Salmonella in vitro and on Fresh Spinach (Spinacia oleracea)

    E-print Network

    Calix Lara, Thelma

    2012-02-14

    ). However, manure is a potential source of a wide variety of human pathogenic microorganisms, including bacteria (Campylobacter coli, C. jejuni, Bacillus anthracis, Brucella abortus, pathogenic and toxigenic strains of E. coli, Leptospira spp., Listeria...

  18. [Research advances in aerobic denitrifiers].

    PubMed

    Wang, Wei; Cai, Zu-cong; Zhong, Wen-hui; Wang, Guo-xiang

    2007-11-01

    This paper reviewed the varieties and characteristics of aerobic denitrifiers, their action mechanisms, and the factors affecting aerobic denitrification. Aerobic denitrifiers mainly include Pseudomonas, Alcaligenes, Paracoccus and Bacillus, which are either aerobic or facultative aerobic, and heterotrophic. They can denitrify under aerobic conditions, with the main product being N2O. They can also convert NH4+ -N to gas product. The nitrate reductase which catalyzes the denitrification is periplasmic nitrate reductase rather than membrane-bound nitrate reductase. Dissolved oxygen concentration and C/N ratio are the main factors affecting aerobic denitrification. The main methods for screening aerobic denitrifiers, such as intermittent aeration and selected culture, were also introduced. The research advances in the application of aerobic denitrifiers in aquaculture, waste water processing, and bio-degradation of organic pollutants, as well as the contributions of aerobic denitrifiers to soil nitrogen emission were summarized. PMID:18260473

  19. Screening genomes of Gram-positive bacteria for

    E-print Network

    Screening genomes of Gram-positive bacteria for double-glycine-motif- containing peptides Secreted-positive bacteria, the double-glycine (GG) motif plays a key role in many peptide secretion systems involved Microbiology Comment #12;peptides and class II bacteriocins, produced by streptococci and lactic acid bacteria

  20. Mini-review Current strategies for improving food bacteria

    Microsoft Academic Search

    Oscar P. Kuipers; Girbe Buist; Jan Kok

    2000-01-01

    Novel concepts and methodologies are emerging that hold great promise for the directed improvement of food-related bacteria, specifically lactic acid bacteria. Also, the battle against food spoilage and pathogenic bacteria can now be fought more effectively. Here we describe recent advances in microbial physiology and genomic research of these organisms that enable novel strategies for obtaining safe, healthy, and good-tasting