WorldWideScience

Sample records for chemical intermediate lactic

  1. Advanced Biocatalytic Processing of Heterogeneous Lignocellulosic Feedstocks to a Platform Chemical Intermediate (Lactic acid Ester)

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Sharon Shoemaker

    2004-09-03

    The development of commercial boi-based processes and products derived from agricultural waste biomass has the potential for significant impact on the economy and security of our nation. Adding value, rather than disposing of the waste of agriculture, can solve an environmental problem and reduce our dependence on foreign sources of fossil fuel for production of chemicals, materials and fuels.

  2. THIN-LAYER SEPARATION OF CITRIC ACID CYCLE INTERMEDIATES, LACTIC ACID, AND THE AMINO ACID TAURINE

    Science.gov (United States)

    This paper describes a two-dimensional mixed-layer method for separating citric acid cycle intermediates, lactic acid and the amino acid taurine. The method cleanly separates all citric acid cycle intermediates tested, excepting citric acid and isocitric acid. The solvents are in...

  3. Treatment of Active Acne Vulgaris by Chemical Peeling Using 88% Lactic Acid

    OpenAIRE

    Khalifa E Sharquie; Adil A Noaimi; Entesar A. Al-Janabi

    2014-01-01

    Introduction: The etiopathogenesis of acne vulgaris is multifactorial, and its therapy is prolonged course that might be not accepted by many patients. Most recently TCA 35% one session peeling gave complete clearance and full remission for active acne vulgaris. Lactic acid has been used effectively as therapeutic topical agents for many skin diseases. Aim: To evaluate the efficacy and safety of chemical peeling using 88% lactic acid solution in the treatment of active acne vulgaris. ...

  4. Surface of Lactic Acid Bacteria: Relationships between Chemical Composition and Physicochemical Properties

    OpenAIRE

    Boonaert, C J; Rouxhet, Paul

    2000-01-01

    The surface chemical composition and physicochemical properties (hydrophobicity and zeta potential) of two lactic acid bacteria, Lactococcus lactis subsp. lactis bv. diacetilactis and Lactobacillus helveticus, have been investigated using cells harvested in exponential or stationary growth phase. The surface composition determined by X-ray photoelectron spectroscopy (XPS) was converted into a molecular composition in terms of proteins, polysaccharides, and hydrocarbonlike compounds. The conce...

  5. The effect of lactic acid bacterial starter culture and chemical additives on wilted rice straw silage.

    Science.gov (United States)

    Wang, Yan-Su; Shi, Wei; Huang, Lin-Ting; Ding, Cheng-Long; Dai, Chuan-Chao

    2016-04-01

    Lactic acid bacteria (LAB) are suitable for rice straw silage fermentation, but have been studied rarely, and rice straw as raw material for ensiling is difficult because of its disadvantages, such as low nutrition for microbial activities and low abundances of natural populations of LAB. So we investigated the effect of application of LAB and chemical additives on the fermentation quality and microbial community of wilted rice straw silage. Treatment with chemical additives increased the concentrations of crude protein (CP), water soluble carbohydrate (WSC), acetic acid and lactic acid, reduced the concentrations of acid detergent fiber (ADF) and neutral detergent fiber (NDF), but did not effectively inhibit the growth of spoilage organisms. Inoculation with LABs did not improve the nutritional value of the silage because of poor growth of LABs in wilted rice straw. Inoculation with LAB and addition of chemical materials improved the quality of silage similar to the effects of addition of chemical materials alone. Growth of aerobic and facultatively anaerobic bacteria was inhibited by this mixed treatment and the LAB gradually dominated the microbial community. In summary, the fermentation quality of wilted rice straw silage had improved by addition of LAB and chemical materials. PMID:26429595

  6. Production of lactic acid using a new homofermentative Enterococcus faecalis isolate

    OpenAIRE

    Subramanian, Mohan Raj; Talluri, Suvarna; Lew P Christopher

    2014-01-01

    Lactic acid is an intermediate-volume specialty chemical for a wide range of food and industrial applications such as pharmaceuticals, cosmetics and chemical syntheses. Although lactic acid production has been well documented, improved production parameters that lead to reduced production costs are always of interest in industrial developments. In this study, we describe the production of lactic acid at high concentration, yield and volumetric productivity utilizing a novel homofermentative, ...

  7. Technological and economic potential of poly(lactic acid) and lactic acid derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Datta, R.; Tsai, S.P.; Bonsignore, P.; Moon, S.H.; Frank, J.R.

    1993-10-01

    Lactic acid has been an intermediate-volume specialty chemical (world production {approximately}40,000 tons/yr) used in a wide range of food processing and industrial applications. lactic acid h,as the potential of becoming a very large volume, commodity-chemical intermediate produced from renewable carbohydrates for use as feedstocks for biodegradable polymers, oxygenated chemicals, plant growth regulators, environmentally friendly ``green`` solvents, and specially chemical intermediates. In the past, efficient and economical technologies for the recovery and purification of lactic acid from crude fermentation broths and the conversion of tactic acid to the chemical or polymer intermediates had been the key technology impediments and main process cost centers. The development and deployment of novel separations technologies, such as electrodialysis (ED) with bipolar membranes, extractive distillations integrated with fermentation, and chemical conversion, can enable low-cost production with continuous processes in large-scale operations. The use of bipolar ED can virtually eliminate the salt or gypsum waste produced in the current lactic acid processes. In this paper, the recent technical advances in tactic and polylactic acid processes are discussed. The economic potential and manufacturing cost estimates of several products and process options are presented. The technical accomplishments at Argonne National Laboratory (ANL) and the future directions of this program at ANL are discussed.

  8. Stereoregularity of poly (lactic acid) and their model compounds as studied by NMR and quantum chemical calculations

    Science.gov (United States)

    In order to understand the origin of the tacticity splitting in the NMR spectrum of poly(lactic acid), monomer model compound and dimer model compounds (both isotactic and syndiotactic) were synthesized and their 1H and 13C NMR chemical shifts observed. Two energetically stable conformations were o...

  9. Use of fungal proteases and selected sourdough lactic acid bacteria for making wheat bread with an intermediate content of gluten.

    Science.gov (United States)

    Rizzello, Carlo Giuseppe; Curiel, José Antonio; Nionelli, Luana; Vincentini, Olimpia; Di Cagno, Raffaella; Silano, Marco; Gobbetti, Marco; Coda, Rossana

    2014-02-01

    This study was aimed at combining the highest degradation of gluten during wheat flour fermentation with good structural and sensory features of the related bread. As estimated by R5-ELISA, the degree of degradation of immune reactive gluten was ca. 28%. Two-dimensional electrophoresis and RP-FPLC analyses showed marked variations of the protein fractions compared to the untreated flour. The comparison was also extended to in vitro effect of the peptic/tryptic-digests towards K562 and T84 cells. The flour with the intermediate content of gluten (ICG) was used for bread making, and compared to whole gluten (WG) bread. The chemical, structural and sensory features of the ICG bread approached those of the bread made with WG flour. The protein digestibility of the ICG bread was higher than that from WG flour. Also the nutritional quality, as estimated by different indexes, was the highest for ICG bread. PMID:24230474

  10. Chemical trapping of labile aldehyde intermediates in the metabolism of propranolol and oxprenolol.

    Science.gov (United States)

    Goldszer, F; Tindell, G L; Walle, U K; Walle, T

    1981-11-01

    Propranolol is N-dealkylated to N-desisopropylpropranolol (DIP) by microsomal enzymes. DIP was shown in this study to be rapidly deaminated by monoamine oxidase (MAO). Thus, incubation of DIP (10(-4) M) with rat liver mitochondria for 90 min demonstrated 74.8 +/- 4.1% metabolism which was almost completely blocked by the MAO inhibitor pargyline (10(-5) M). The end products of this deamination were 3-(alpha-naphthoxy)-1,2-propylene glycol (Glycol) and 3-(alpha-naphthoxy)lactic acid (NLA). In the presence of excess NADH the Glycol was the major product whereas NLA was the major product in the presence of excess NAD+. The intermediate aldehyde in this deamination reaction, 3-(alpha-naphthoxy)-2-hydroxypropanal (Ald), was extremely labile and decomposed quantitatively to alpha-naphthol when removed from the incubates. However, the addition of methoxyamine hydrochloride directly to the incubates made it possible to chemically trap the intact Ald as an O-methyloxime and prove its structure by gas chromatography-mass spectrometry. The deamination of the primary amine of oxprenolol also gave rise to a labile aldehyde which could be trapped and identified as its O-methyloxime. PMID:7335950

  11. Cosmic chemical evolution with intermediate mass pop III stars

    International Nuclear Information System (INIS)

    We explore the consequences of an early population of intermediate mass stars (IMS) in the 2 – 8 Msun range on cosmic chemical evolution. We discuss the implications of this population as it pertains to several cosmological and astrophysical observables. Some very metal-poor galactic stars show large enhancements of carbon, typical of the C-rich ejecta of IMS; moreover, halo star carbon and oxygen abundances show a scatter, which imply a wide range of star-formation and nucleosynthetic histories contributed to the first generations of stars. Also, recent analyses of the He abundance in metal-poor extragalactic H II regions suggest an elevated primitive abundance of Helium, Yp ≅ 0.256 by mass, higher than the predicted result from big bang nucleosynthesis assuming the baryon density determined by WMAP, Yp ≅ 0.249. This offset suggests a prompt initial enrichment of He in early metal-poor structures, and IMS Pop III stars are again good candidates. We also discuss the effect of these Pop III stars on global cosmic evolution for example the reionization of the Universe. We conclude that if IMS are to be associated with some Population III stars, their relevance is limited to low mass structures involving a little fraction of the total baryon content of the Universe typical at redshift 10 [1].

  12. Intermediate mass dilepton production in a chemically equilibrating quark-gluon matter

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    We find that in a chemically equilibrating baryon-rich quark-gluon matter, due to the slow cooling rate, high initial temperature, large gluon density as well as large fusion cross section ofin the intermediate mass region, the gluon fusion provides a dominant contribution to dileptons with intermediate masses, resulting in the significant enhancement of intermediate mass dileptons.

  13. Physico-chemical parameter for production of lactic acid or ethanol of (corynebacterium glutamicum) bacteria

    International Nuclear Information System (INIS)

    The interest to obtain products for the bio-fuel industry from renewable resources has directed research to find resistant and costs-effective biotechnological systems. Corynebacterium glutamicum, is a microorganism used to produce amino acids, that grows in wide variety of substrates and its resistance during fermentation to pH, temperature, osmotic pressure variations and alcohol aggregate, renders this organism a suitable candidate to improve by genetic modifications lactic acid and ethanol synthesis. However, some aspects of its physiology remain unknown, such us increase lactic acid and ethanol production from C5 and C6 sugars. For this reason, the main aim in our work was to identify the most important variables with impact on culture and the best culture conditions to produce lactic acid or ethanol in batch culture. To achieve this objective, eight variables were tested in culture using a statistical model. The best culture conditions were obtained and tested in a bacth bioreactor system. Temperature, biotin and glucose concentration were the variables with most impact (p-1, 16 g/l of lactic acid was obtained after 15 h of culture with an efficiency of 32%. High glucose consumption was observed during bacterial growth, which leads to low concentration of substrate for the production process; this suggests a culture feeding at the end of exponential growth phase, which can increase the production yield.

  14. Physio-chemical, microbiological properties of tempoyak and molecular characterisation of lactic acid bacteria isolated from tempoyak.

    Science.gov (United States)

    Chuah, Li-Oon; Shamila-Syuhada, Ahamed Kamal; Liong, Min Tze; Rosma, Ahmad; Thong, Kwai Lin; Rusul, Gulam

    2016-09-01

    This study aims to determine physio-chemical properties of tempoyak, characterise the various indigenous species of lactic acid bacteria (LAB) present at different stages of fermentation and also to determine the survival of selected foodborne pathogens in tempoyak. The predominant microorganisms present in tempoyak were LAB (8.88-10.42 log CFU/g). Fructobacillus durionis and Lactobacillus plantarum were the dominant members of LAB. Other LAB species detected for the first time in tempoyak were a fructophilic strain of Lactobacillus fructivorans, Leuconostoc dextranicum, Lactobacillus collinoides and Lactobacillus paracasei. Heterofermentative Leuconostoc mesenteroides and F. durionis were predominant in the initial stage of fermentation, and as fermentation proceeded, F. durionis remained predominant, but towards the end of fermentation, homofermentative Lb. plantarum became the predominant species. Lactic, acetic and propionic acids were present in concentrations ranging from 0.30 to 9.65, 0.51 to 7.14 and 3.90 to 7.31 mg/g, respectively. Genotyping showed a high degree of diversity among F. durionis and Lb. plantarum isolates, suggesting different sources of LAB. All tested Lb. plantarum and F. durionis (except for one isolate) isolates were multidrug resistant. Salmonella spp., Listeria monocytogenes and Staphylococcus aureus were not detected. However, survival study showed that these pathogens could survive up to 8-12 days. The results aiming at improving the quality and safety of tempoyak. PMID:27217364

  15. Chemical Synthesis and Optical Properties of CdS Poly(Lactic Acid) Nanocomposites and Their Transparent Fluorescent Films

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Cai-Feng [Nanjing University of Technology; Cheng, Yu-Peng [Nanjing University of Technology; Xie, He-Yi [Nanjing University of Technology; Chen, Li [Nanjing University of Technology; Hu, Michael Z. [ORNL; Chen, Su [Nanjing University of Technology

    2011-01-01

    This paper describes the chemical synthesis of cadmium sulfide (CdS) polymer nanocomposites by covalently grafting poly(lactic acid) (PLA) onto the surfaces of CdS nanocrystals (NCs). Synthesis of the nanocomposites involved two steps. Lactic acid (LA) capped CdS NCs were first prepared by reacting cadmium chloride (CdCl2) with sodium sulfide (Na2S) using LA as the organic ligand in H2O/N,N-dimethylformamide (DMF) solution. Next CdS PLA nanocomposites were formed by in situ ring-opening polymerization of lactide on the surface of modified CdS NCs. Transparent fluorescent films were then successfully prepared by blending as-prepared CdS PLA nanocomposites with high-molecular-weight PLA. The as-prepared CdS NCs and their nanocomposites were studied by transmission electron microscopic imaging, thermogravimetric analyses, and spectroscopic measurements (ultraviolet-visible absorption and photoluminescence). The spectroscopic studies revealed that the CdS polymer nanocomposites exhibited good optical properties in terms of their photoluminescence and transparency.

  16. Lactic Acidosis

    OpenAIRE

    K.Srikanth

    2012-01-01

    Abstract. Lactic acidosis is a broad-anion gap metabolic acidosis caused by lactic acid overproduction or underutilization. The quantitative dimensions of these two mechanisms commonly differ by 1 order of magnitude. Overproduction of lactic acid, also termed type A lactic acidosis, occurs when the body must regenerate ATP without oxygen (tissue hypoxia). Circulatory, pulmonary, or hemoglobin transfer disorders are commonly responsible. Overproduction of lactate also occurs with cyanide poiso...

  17. Management of low and intermediate level radioactive wastes with regard to their chemical toxicity

    International Nuclear Information System (INIS)

    A preliminary overview is provided of management options for low and intermediate level radioactive waste (LILW) with regard to its chemical toxicity. In particular, the following issues are identified and described associated with the management and safe disposal of chemically toxic materials in LILW: the origin and characteristics; the regulatory approaches; the pre-disposal management; the disposal; the safety assessment. Also included are: regulatory framework for chemically toxic low level wastes in the USA; pre-disposal processing options for LILW containing chemically toxic components; example treatment technologies for LILW containing chemically toxic components and safety assessment case studies for Germany, Belgium, France and Sweden

  18. Production of lactic acid using a new homofermentative Enterococcus faecalis isolate.

    Science.gov (United States)

    Subramanian, Mohan Raj; Talluri, Suvarna; Christopher, Lew P

    2015-03-01

    Lactic acid is an intermediate-volume specialty chemical for a wide range of food and industrial applications such as pharmaceuticals, cosmetics and chemical syntheses. Although lactic acid production has been well documented, improved production parameters that lead to reduced production costs are always of interest in industrial developments. In this study, we describe the production of lactic acid at high concentration, yield and volumetric productivity utilizing a novel homofermentative, facultative anaerobe Enterococcus faecalis CBRD01. The highest concentration of 182 g lactic acid l(-1) was achieved after 38 h of fed-batch fermentation on glucose. The bacterial isolate utilized only 2-13% of carbon for its growth and energy metabolism, while 87-98% of carbon was converted to lactic acid at an overall volumetric productivity of 5 g l(-1)  h(-1). At 13 h of fermentation, the volumetric productivity of lactate production reached 10.3 g l(-1)  h(-1), which is the highest ever reported for microbial production of lactic acid. The lactic acid produced was of high purity as formation of other metabolites was less than 0.1%. The present investigation demonstrates a new opportunity for enhanced production of lactic acid with potential for reduced purification costs. PMID:24894833

  19. Intermediate mass dilepton production during the chemical equilibration of quark gluon plasma

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The production of dileptons from the chemically equilibrating quark gluon plasma in the intermediate mass region has been studied. Comparing with the calculated results based on the thermodynamic equilibrium system of quark gluon plasma, it has been found that the quark phase of the chemically equilibrating system gives rise to an even larger enhancement of the dileptons production. Therefore, such an enhancement of dilepton production may signal the formation of quark gluon plasma.

  20. Lactic Acidosis

    Directory of Open Access Journals (Sweden)

    K.Srikanth

    2012-10-01

    Full Text Available Abstract. Lactic acidosis is a broad-anion gap metabolic acidosis caused by lactic acid overproduction or underutilization. The quantitative dimensions of these two mechanisms commonly differ by 1 order of magnitude. Overproduction of lactic acid, also termed type A lactic acidosis, occurs when the body must regenerate ATP without oxygen (tissue hypoxia. Circulatory, pulmonary, or hemoglobin transfer disorders are commonly responsible. Overproduction of lactate also occurs with cyanide poisoning or certain malignancies. Underutilization involves removal of lactic acid by oxidation or conversion to glucose. Liver disease, inhibition of gluconeogenesis, pyruvate dehydrogenase (thiamine deficiency, and uncoupling of oxidative phosphorylation are the most common causes. The kidneys also contribute to lactate removal. Concerns have been raised regarding the role of metformin in the production of lactic acidosis, on the basis of individual case reports. The risk appears to be considerably less than with phenformin and involves patients with underlying severe renal and cardiac dysfunction.

  1. Intermediate Mass Dilepton Production in a Chemically Equilibrating Quark-Gluon Matter

    Institute of Scientific and Technical Information of China (English)

    HE Ze-Jun; ZHOU Wen-Jie; ZHANG Jia-Ju; LIU Bo

    2001-01-01

    Dilepton production during the chemical equilibration of quark-gluon matter with a finite baryon density has been studied. We find that due to the slowing down of the cooling rate and the high initial temperature of the quark-gluon matter produced at RHIC energies, the quark phase contribution to dileptons with intermediate masses is significantly heightened and is much larger than that calculated by the evolution of the thermodynamic equilibrium system. The latter has shown an enhancement of intermediate mass dileptons from the quark phase. Therefore, such an enhancement of dileptons should be a signature for quark-gluon matter formation.

  2. Chemical intermediate detection following corona discharge on volatile organic compounds: general method using molecular beam techniques

    International Nuclear Information System (INIS)

    Nonthermal plasma (NTP)-based treatments of volatile organic compounds (VOCs) have potential for effective environmental remediation. Theory and experiment that consider the basic science pertaining to discharge events have helped improve NTP remediation outcomes. If direct information on early post-discharge chemical intermediates were also available, it would likely lead to additional improvement in NTP remediation outcomes. To this point, however, experiments yielding direct information on post-NTP VOC intermediates have been limited. An approach using supersonic expansion molecular beam methods offers general promise for detection of post-discharge VOC intermediates. To illustrate the potential utility of these methods, we present mass spectra showing the growth of early products formed when pulsed corona discharges were carried out on toluene in He and then in He with added O2. Good general detection of neutral post-discharge species was obtained using 800 nm 150 fs photoionization pulses.

  3. Chemical intermediate detection following corona discharge on volatile organic compounds: general method using molecular beam techniques

    Energy Technology Data Exchange (ETDEWEB)

    He Luning; Sulkes, Mark, E-mail: cm06acf@tulane.edu [Chemistry Department, Tulane University, New Orleans, LA 70118 (United States)

    2011-07-13

    Nonthermal plasma (NTP)-based treatments of volatile organic compounds (VOCs) have potential for effective environmental remediation. Theory and experiment that consider the basic science pertaining to discharge events have helped improve NTP remediation outcomes. If direct information on early post-discharge chemical intermediates were also available, it would likely lead to additional improvement in NTP remediation outcomes. To this point, however, experiments yielding direct information on post-NTP VOC intermediates have been limited. An approach using supersonic expansion molecular beam methods offers general promise for detection of post-discharge VOC intermediates. To illustrate the potential utility of these methods, we present mass spectra showing the growth of early products formed when pulsed corona discharges were carried out on toluene in He and then in He with added O{sub 2}. Good general detection of neutral post-discharge species was obtained using 800 nm 150 fs photoionization pulses.

  4. Intermediate-range chemical ordering of cations in molten RbCl-AgCl

    Energy Technology Data Exchange (ETDEWEB)

    Tahara, S. [Department of Physics and Earth Sciences, Faculty of Science, University of the Ryukyus, Okinawa 903-0213 (Japan); Research and Utilization Division, Japan Synchrotron Radiation Research Institute (JASRI, SPring-8), Hyogo 679-5198 (Japan); Kawakita, Y. [J-PARC Center, Japan Atomic Energy Agency (JAEA), Ibaraki 319-1195 (Japan); Shimakura, H. [Faculty of Pharmacy, Niigata University of Pharmacy and Applied Life Sciences, Niigata 956-8603 (Japan); Ohara, K. [Research and Utilization Division, Japan Synchrotron Radiation Research Institute (JASRI, SPring-8), Hyogo 679-5198 (Japan); Fukami, T. [Department of Physics and Earth Sciences, Faculty of Science, University of the Ryukyus, Okinawa 903-0213 (Japan); Takeda, S. [Department of Physics, Faculty of Sciences, Kyushu University, Fukuoka 812-8581 (Japan)

    2015-07-28

    A first sharp diffraction peak (FSDP) is observed in the X-ray total structure factor of a molten mixture of RbCl-AgCl, while both pure melts of RbCl and AgCl do not exhibit FSDP individually. Molecular dynamics simulations were performed to investigate the origin of the FSDP with the polarizable ion model (PIM). Coexistence of covalent Ag–Cl and ionic Rb–Cl bonds leads the system to evolve intermediate range ordering, which is simulated by introducing the induced polarization in different ways between Ag–Cl with fully polarizable treatment based on Vashishta-Raman potential and Rb–Cl with suppression over-polarization in the nearest neighbor contribution based on Born-Meyer potential. The partial structure factors for both the Ag–Ag and Rb–Rb correlations, S{sub AgAg}(Q) and S{sub RbRb}(Q), show a positive contribution to the FSDP, while S{sub AgRb}(Q) for the Ag–Rb correlation exhibits a negative contribution, indicating that Ag and Rb ions are distributed in an alternating manner within the intermediate-range length scale. The origin of the intermediate-range chemical ordering of cations can be ascribed to the preferred direction of the dipole moments of anions in the PIM.

  5. Intermediate-range chemical ordering of cations in molten RbCl-AgCl

    International Nuclear Information System (INIS)

    A first sharp diffraction peak (FSDP) is observed in the X-ray total structure factor of a molten mixture of RbCl-AgCl, while both pure melts of RbCl and AgCl do not exhibit FSDP individually. Molecular dynamics simulations were performed to investigate the origin of the FSDP with the polarizable ion model (PIM). Coexistence of covalent Ag–Cl and ionic Rb–Cl bonds leads the system to evolve intermediate range ordering, which is simulated by introducing the induced polarization in different ways between Ag–Cl with fully polarizable treatment based on Vashishta-Raman potential and Rb–Cl with suppression over-polarization in the nearest neighbor contribution based on Born-Meyer potential. The partial structure factors for both the Ag–Ag and Rb–Rb correlations, SAgAg(Q) and SRbRb(Q), show a positive contribution to the FSDP, while SAgRb(Q) for the Ag–Rb correlation exhibits a negative contribution, indicating that Ag and Rb ions are distributed in an alternating manner within the intermediate-range length scale. The origin of the intermediate-range chemical ordering of cations can be ascribed to the preferred direction of the dipole moments of anions in the PIM

  6. Chemical conditions in the repository for low- and intermediate-level reactor waste

    International Nuclear Information System (INIS)

    The chemical conditions in the proposed repositories for low- and intermediate-level reactor waste at Haestholmen (IVO) and Olkiluoto (TVO) have been discussed with respect to materials introduced into the repository, their possible long-term changes and interaction with groundwater flowing into the repository. The main possible groundwater-rock interactions have been discussed, as well as the role of micro-organisms, organic acids and colloids in the estimation of the barrier integrity. Experimental and theoretical studies have been performed on the basis of the natural groundwater compositions expected at the repository sites. Main emphasis is put on the chemical parameters which might influence the integrity of the different barriers in the repository as well as on the parameters which might effect the release and transport of radionuclides from the repository

  7. Effects of lactic acid bacteria with bacteriocinogenic potential on the fermentation profile and chemical composition of alfalfa silage in tropical conditions.

    Science.gov (United States)

    Silva, V P; Pereira, O G; Leandro, E S; Da Silva, T C; Ribeiro, K G; Mantovani, H C; Santos, S A

    2016-03-01

    The fermentation profile, chemical composition, and microbial populations of alfalfa silages treated with microbial inoculants (MI) at different fermentation periods (T) were evaluated in tropical conditions. A 4×6 factorial arrangement was used in a randomized design with 3 replicates. Fresh alfalfa was treated with (1) no treatment (CTRL), (2) commercial inoculant (CIN), (3) Pediococcus acidilactici (strain 10.6, S1), and (4) Pediococcus pentosaceus (strain 6.16, S2). An inoculant application rate of 10(6) cfu/g of fresh forage was used. The fermentation periods were 1, 3, 7, 14, 28, and 56 d. Alfalfa was harvested 82 d after sowing at the early flowering stage, chopped into 1.5-cm particle size, and ensiled in 25 × 35 cm vacuum-sealed plastic bags. The numbers of lactic acid bacteria, enterobacteria, mold, and yeast in alfalfa before ensiling were 5.42, 5.58, 4.82, and 4.8 log cfu/g, respectively. Silage chemical composition was evaluated only at 56 d. All parameters were affected by the interaction MI × T, except the concentrations of lactic and propionic acids. Alfalfa silage treated with S1 or S2 had lower pH values than CTRL from the first day until 28 d. However, the inoculants resulted in similar pH after 56 d, and these values were lower than the CTRL. The highest concentration of lactic acid was observed in the silage treated with S1 and S2 at 7 and 14 d of ensiling. The concentration of acetic acid was lower in the silages treated with S1 and S2 than the CTRL and CIN at 3 and 28 d of fermentation. There was no effect of MI or MI × T interaction on the microbial populations. However, the number of enterobacteria decreased over the fermentation period until 14 d and increased slightly after this time point. The chemical composition of alfalfa silage was not affected by MI at 56 d of ensiling. The strain P. pentosaceus 6.16 was the most efficient in dominating the fermentation process by decreasing the pH more quickly and increasing the concentration

  8. Ion-radical intermediates of the radiation-chemical transformations of organic carbonates

    Science.gov (United States)

    Shiryaeva, Ekaterina S.; Sosulin, Ilya S.; Saenko, Elizaveta V.; Feldman, Vladimir I.

    2016-07-01

    The spectral features and reactions of ion-radical intermediates produced from organic carbonates in low-temperature matrices were investigated by EPR spectroscopy and quantum-chemical calculations. It was shown that radical cations of diethyl carbonate and dimethyl carbonate underwent intramolecular hydrogen transfer to yield alkyl-type species, as was suggested previously. Meanwhile, radical cation of EC demonstrates a ring cleavage even at 77 K, while radical cation of PC is probably intrinsically stable and undergo an ion-molecule reaction with a neighboring neutral molecule in dimers or associates. Radical anions were obtained in glassy matrices of diethyl ether or perdeuteroethanol. The radical anions of linear carbonates show photoinduced fragmentation to yield the corresponding alkyl radicals; such process may also occur directly under radiolysis. Radical anions of cyclic carbonates are relatively stable and yield only trace amounts of fragmentation products under similar conditions.

  9. Green chemical synthesis of poly(lactic acid) based biodegradable polymers%聚乳酸降解材料的绿色化学合成

    Institute of Scientific and Technical Information of China (English)

    许文殊; 罗祥林

    2011-01-01

    背景:聚乳酸具有良好的生物相容性和生物降解性,广泛应用于药物缓释、手术缝合线、组织工程支架及骨修复材料等生物医用领域.但其常规合成方法需使用溶剂,生产效率较低且成本较高.目的:对非溶剂的绿色化学方法-乳酸熔融缩聚/二异氰酸酯熔融扩链,合成聚乳酸降解材料的研究进展进行综述.方法:应用计算机检索SCI-Expanded数据库(1995-01/2010-06),以"Poly(lactic acid),diisocyanate"为检索词;应用计算机检索中国期刊网络出版总库(1999-01/2010-06),以"聚乳酸,异氰酸酯"为检索词.共收集130篇关于乳酸熔融缩聚/二异氰酸酯熔融扩链的文献,中文39篇,英文91篇.排除发表内容重复、实验结果较差的文献,共32篇文献符合标准被纳入.结果与结论:采用非溶剂的绿色化学方法-乳酸熔融缩聚/二异氰酸酯熔融扩链,通过改变异氰酸酯和预聚物的种类和比例,就可以制备具有不同相对分子质量和性能的可降解聚乳酸基聚氨酯材料,有望在生物医用领域和日常生活中取得实际的应用.%BACKGROUND: Poly(lactic acid) has excellent biocompatibility and biodegradability, thus it has been widely used in many biomedical fields, such as drug delayed release, surgical suture, tissue engineering scaffold and bone substitutes. Routine synthesis requires the use of solvent, showing low production efficacy and high cost.OBJECTIVE: Non-solvent green chemical synthesis of poly(lactic acid) based biodegradable materials via direct condensation polymerization and chain extension in melt state were reviewed.METHODS: A computer-based online search of SCI-Expanded database (1995-01/2010-06) and China Academic Journal Network Publishing Database was performed for related articles with the key words of "poly (lactic acid), diisocyanate" in English and in Chinese. A total of 130 articles regarding the lactic acid polycondensation/diisocyanate chain extension in melt

  10. Unexpected tautomeric equilibria of the carbanion-enamine intermediate in pyruvate oxidase highlight unrecognized chemical versatility of thiamin

    OpenAIRE

    Meyer, Danilo; Neumann, Piotr; Koers, Eline; Sjuts, Hanno; Lüdtke, Stefan; Sheldrick, George M.; Ficner, Ralf; Tittmann, Kai

    2012-01-01

    Thiamin diphosphate, the vitamin B1 coenzyme, plays critical roles in fundamental metabolic pathways that require acyl carbanion equivalents. Studies on chemical models and enzymes had suggested that these carbanions are resonance-stabilized as enamines. A crystal structure of this intermediate in pyruvate oxidase at 1.1 Å resolution now challenges this paradigm by revealing that the enamine does not accumulate. Instead, the intermediate samples between the ketone and the carbanion both inter...

  11. Methyldichloroborane evidenced as an intermediate in the chemical vapour deposition synthesis of boron carbide.

    Science.gov (United States)

    Reinisch, G; Patel, S; Chollon, G; Leyssale, J-M; Alotta, D; Bertrand, N; Vignoles, G L

    2011-09-01

    The most recent ceramic-matrix composites (CMC) considered for long-life applications as thermostructural parts in aerospace propulsion contain, among others, boron-rich phases like boron carbide. This compound is prepared by thermal Chemical Vapour Infiltration (CVI), starting from precursors like boron halides and hydrocarbons. We present a study aiming at a precise knowledge of the gas-phase composition in a hot-zone LPCVD reactor fed with BCl3, CH4 and H2, which combines experimental and theoretical approaches. This work has brought strong evidences of the presence of Methydichloroborane (MDB, BCl2CH3) in the process. It is demonstrated that this intermediate, the presence of which had never been formally proved before, appears for processing temperatures slightly lower than the deposition temperature of boron carbide. The study features quantum chemical computations, which provide several pieces of information like thermochemical and kinetic data, as well as vibration and rotation frequencies, reaction kinetics computations, and experimental gas-phase characterization of several species by FTIR, for several processing parameter sets. The main results are presented, and the place of MDB in the reaction scheme is discussed. PMID:22097577

  12. Effect of temperature-controlled fermentation on physico-chemical properties and lactic acid bacterial count of durian (Durio zibethinus Murr.) pulp.

    Science.gov (United States)

    Wasnin, Ramdiah M; Karim, Muhammad Shahrim Abdul; Ghazali, Hasanah Mohd

    2014-11-01

    Effects of controlled-temperature fermentation on several physico-chemical properties, lactic acid bacteria (LAB) counts and aroma of durian pulp were examined by storing fresh durian pulp was mixed with 2 % (w/w) salt and stored at 15 °C, 27 °C and 40 °C for 10 days. Storage at 15 °C did not affect the properties of the pulp much. However, at 27 °C and 40 °C, pH and total soluble solids decreased up to 60 % and 52 %, respectively, with greater losses at 27 °C. Titratable acidity, which increased at 27 °C, was due to lactic and acetic acids formation. Loss of sucrose and increases in glucose were greater at 27 °C. LAB population increased up to Day 3 of storage, and then decreased slightly. Principal component analysis based on aroma examination using a zNose(TM) showed better retention of aroma profile at 27 °C. Overall, durian fermented at 27 °C was more acceptable than the one prepared at 40 °C, and it is ready to be consumed between Day 4 and 6. PMID:26396291

  13. Selective Chemical Conversion of Sugars in Aqueous Solutions without Alkali to Lactic Acid Over a Zn-Sn-Beta Lewis Acid-Base Catalyst

    Science.gov (United States)

    Dong, Wenjie; Shen, Zheng; Peng, Boyu; Gu, Minyan; Zhou, Xuefei; Xiang, Bo; Zhang, Yalei

    2016-05-01

    Lactic acid is an important platform molecule in the synthesis of a wide range of chemicals. However, in aqueous solutions without alkali, its efficient preparation via the direct catalysis of sugars is hindered by a side dehydration reaction to 5-hydroxymethylfurfural due to Brønsted acid, which originates from organic acids. Herein, we report that a previously unappreciated combination of common two metal mixed catalyst (Zn-Sn-Beta) prepared via solid-state ion exchange synergistically promoted this reaction. In water without a base, a conversion exceeding 99% for sucrose with a lactic acid yield of 54% was achieved within 2 hours at 190 °C under ambient air pressure. Studies of the acid and base properties of the Zn-Sn-Beta zeolite suggest that the introduction of Zn into the Sn-Beta zeolite sequentially enhanced both the Lewis acid and base sites, and the base sites inhibited a series of side reactions related to fructose dehydration to 5-hydroxymethylfurfural and its subsequent decomposition.

  14. Effects of synthesis conditions on chemical structures and physical properties of copolyesters from lactic acid, ethylene glycol and dimethyl terephthalate

    Directory of Open Access Journals (Sweden)

    2009-07-01

    Full Text Available Lactic acid/ethylene terephthalate copolyesters were synthesized by the standard melt polycondensation of lactic acid (L, ethylene glycol (EG and dimethyl-terephthalate (DMT. Effects of reaction temperatures and types of catalysts on the structures and properties of the copolymers were examined. In addition, feasibility of promoting the copolymerization process by a novel synthesis step of using thermo-stabilizers was investigated. The results show that a reaction temperature of higher than 180°C is necessary to produce copolymers with appreciable molecular weight. However, degradation was observed when the reaction temperature is higher than 220°C. Triphenyl phosphate (TPP shows promising results as a potential thermo-stabilizer to minimize this problem. It was found that Sb2O3 and Tin(II octoate are most effective among 4 types of catalysts employed in this study. 1H-NMR results indicate that copolymers have a random microstructure composed mainly of single L units alternately linked with ET blocks at various sequential lengths. The longer ET sequence in the chain structure leads to the increase in melting temperature of the copolymer. TGA results show that the resulting copolymers possessed greater thermal stability than commercially-available aliphatic PLA, as a result of the inclusion of T (terephthalate units in the chain structure.

  15. Determination of Ascorbic Acid Using a New Oscillating Chemical System of Lactic Acid-Acetone-BrO3--Mn2+-H2SO4

    Institute of Scientific and Technical Information of China (English)

    YANG,Shu-Tao(杨树涛); LIN,Zhi-Xin(林智信); CAI,Ru-Xiu(蔡汝秀); GAN,Nan-Qin(甘南琴)

    2002-01-01

    Analyte pulse perturbation ( APP ) technique was applied to the study of the perturbation of ascorbic acid (AA) on the lactic acid-acetone-BrO3--Mn2+-H2SO4 oscllating reaction, and AA was determined using this new oscillating chemical system. Influence of experimental variables was investigated. The linear range lies between 5.0 × 10-7-5.5 × 10-5 mol/L, and the precision and throughput were quite good (2.43% as RSD,and 8-10 samples/h, respectively). This method was applied to the determination of real samples and the results were satisfactory. Some aspects of the potential mechanism of action of AA on the oscillating systems are discussed.

  16. Chemical composition, silage fermentation characteristics, and in vitro ruminal fermentation parameters of potato-wheat straw silage treated with molasses and lactic acid bacteria and corn silage.

    Science.gov (United States)

    Babaeinasab, Y; Rouzbehan, Y; Fazaeli, H; Rezaei, J

    2015-09-01

    The aim of this study was to determine the effect of molasses and lactic acid bacteria (LAB) on the chemical composition, silage fermentation characteristics, and in vitro ruminal fermentation parameters of an ensiled potato-wheat straw mixture in a completely randomized design with 4 replicates. Wheat straw was harvested at full maturity and potato tuber when the leaves turned yellowish. The potato-wheat straw (57:43 ratio, DM basis) mixture was treated with molasses, LAB, or a combination. Lalsil Fresh LB (Lallemand, France; containing NCIMB 40788) or Lalsil MS01 (Lallemand, France; containing MA18/5U and MA126/4U) were each applied at a rate of 3 × 10 cfu/g of fresh material. Treatments were mixed potato-wheat straw silage (PWSS) without additive, PWSS inoculated with Lalsil Fresh LB, PWSS inoculated with Lalsil MS01, PWSS + 5% molasses, PWSS inoculated with Lalsil Fresh LB + 5% molasses, PWSS inoculated with Lalsil MS01 + 5% molasses, and corn silage (CS). The compaction densities of PWSS treatments and CS were approximately 850 and 980 kg wet matter/m, respectively. After anaerobic storage for 90 d, chemical composition, silage fermentation characteristics, in vitro gas production (GP), estimated OM disappearance (OMD), ammonia-N, VFA, microbial CP (MCP) production, and cellulolytic bacteria count were determined. Compared to CS, PWSS had greater ( < 0.001) values of DM, ADL, water-soluble carbohydrates, pH, and ammonia-N but lower ( < 0.05) values of CP, ash free-NDF (NDFom), ash, nitrate, and lactic, acetic, propionic, and butyric acids concentrations. When PWSS was treated with molasses, LAB, or both, the contents of CP and lactic and acetic acids increased, whereas NDFom, ammonia-N, and butyric acid decreased ( < 0.05). Based on in vitro ruminal experiments, PWSS had greater ( < 0.05) values of GP, OMD, and MCP but lower ( < 0.05) VFA and acetic acid compared to CS. With adding molasses alone or in combination with LAB inoculants to PWSS, the values of GP

  17. The impact of fermentation with exopolysaccharide producing lactic acid bacteria on rheological, chemical and sensory properties of pureed carrots (Daucus carota L.).

    Science.gov (United States)

    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 β-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 β-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

  18. Observation of a chemically labile, noncovalent enzyme intermediate in the reaction of metal-dependent Aquifex pyrophilus KDO8PS by time-resolved mass spectrometry

    OpenAIRE

    Roberts, Anne; Furdui, Cristina; Anderson, Karen S.

    2010-01-01

    The direct detection of intermediates in enzymatic reactions can yield important mechanistic insights but may be difficult due to short intermediate lifetimes and chemical instability. Using a rapid-mixing device coupled with electrospray ionization time-of-flight mass spectrometry, the noncova-lent hemiketal intermediate in the reaction of metal-dependent 3-deoxy-D-manno-octulosonate-8-phosphate (KDO8P) synthase from Aquifex pyrophilus was observed in the millisecond time range. Using single...

  19. Biocide tolerance, phenotypic and molecular response of lactic acid bacteria isolated from naturally-fermented Aloreña table to different physico-chemical stresses.

    Science.gov (United States)

    Casado Muñoz, María Del Carmen; Benomar, Nabil; Lavilla Lerma, Leyre; Knapp, Charles W; Gálvez, Antonio; Abriouel, Hikmate

    2016-12-01

    Lactic acid bacteria (LAB) isolated throughout the fermentation process of Aloreña table olives were found to be resistant at least to three antibiotics (Casado Muñoz et al., 2014); however, most were sensitive to the biocides tested in this study (with minimum inhibitory concentrations [MIC] below the epidemiological cut-off values). 2-15% of the isolates were found to be biocide resistant: Leuconostoc Pseudomesenteroides, which were resistant to hexachlorophene, and Lactobacillus pentosus to cetrimide and hexadecylpiridinium. We analyzed the effect of different physico-chemical stresses, including antimicrobials, on the phenotypic and genotypic responses of LAB, providing new insights on how they become resistant in a changing environment. Results indicated that similar phenotypic responses were obtained under three stress conditions: antimicrobials, chemicals and UV light. Susceptibility patterns to antibiotics changed: increasing MICs for ampicillin, chloramphenicol, ciprofloxacin, teicoplanin and tetracycline, and decreasing the MICs for clindamycin, erythromycin, streptomycin and trimethoprim in most strains. Statistically, cross resistance between different antibiotics was detected in all stress conditions. However, expression profiles of selected genes involved in stress/resistance response (rpsL, recA, uvrB and srtA) differed depending on the stress parameter, LAB species and strain, and the target gene. We conclude that, despite the uniform phenotypic response to stresses, the repertoire of induced and repressed genes differs. So, a search for a target to improve stress tolerance of LAB, especially those of importance as starter/protective cultures or probiotics, may depend on the individual screening of each strain, even though we could predict the antibiotic phenotypic response to all stresses. PMID:27554140

  20. Intermediate sp-hybridization for chemical bonds in nonplanar covalent molecules of carbon

    International Nuclear Information System (INIS)

    General representations for symmetrical and asymmetrical intermediate sp-hybridization are provided, with which the development of electronic structure in C3v-symmetrical C2H6 and the bonding configuration in C60 have been analyzed as an example. The spherical structure of C60 does not necessarily require the fourth hybrid, h4, to lie along the radial direction. Rather, h4 runs at an angle of 3.83° from the radius, in the plane bisecting a pentagon, to achieve maximum overlap with adjacent h4-hybrids. By virtue of these representations, a number of properties of covalent molecules and solids can be conveniently calculated. This work might be particularly helpful for the study of C—C bonding in curved structures of carbon, such as fullerenes, carbon nanotubes, and buckled graphene

  1. Synthesis and applications of 2-aminopyrimidine derivatives as key intermediates in chemical synthesis of biomolecules

    Science.gov (United States)

    Koroleva, Elena V.; Gusak, K. N.; Ignatovich, Zh V.

    2010-10-01

    Published data on the main approaches to the formation of the heterocyclic 2-aminopyrimidine system, which is one of important pharmacophores responsible for the biological properties of its derivatives, are described systematically. Main chemical transformations of functionalized 2-aminopyrimidines and their application in the synthesis of modern pharmaceuticals are considered.

  2. Synthesis and applications of 2-aminopyrimidine derivatives as key intermediates in chemical synthesis of biomolecules

    Energy Technology Data Exchange (ETDEWEB)

    Koroleva, Elena V; Gusak, K N; Ignatovich, Zh V [Institute of Chemistry of New Materials of the National Academy of Sciences of Belarus (Belarus)

    2010-10-19

    Published data on the main approaches to the formation of the heterocyclic 2-aminopyrimidine system, which is one of important pharmacophores responsible for the biological properties of its derivatives, are described systematically. Main chemical transformations of functionalized 2-aminopyrimidines and their application in the synthesis of modern pharmaceuticals are considered.

  3. Derivation of chemical abundances in star-forming galaxies at intermediate redshift

    CERN Document Server

    Perez-Martinez, J M

    2014-01-01

    We have studied a sample of 11 blue, luminous, metal-poor galaxies at redshift 0.744 < z < 0.835 from the DEEP2 redshift survey. They were selected by the presence of the [OIII]4363 auroral line and the [OII]3726,3729 doublet together with the strong emission nebular [OIII] lines in their spectra from a sample of around 6000 galaxies within a narrow redshift range. All the spectra have been taken with DEIMOS, which is a multi-slit, double-beam spectrograph which uses slitmasks to allow the spectra from many objects to be imaged at the same time. The selected objects present high luminosities (20.3 < MB < 18.5), remarkable blue color index, and total oxygen abundances between 7.69 and 8.15 which represent 1/3 to 1/10 of the solar value. The wide spectral coverage (from 6500 to 9100 angstroms) of the DEIMOS spectrograph and its high spectral resolution, R around 5000, bring us an opportunity to study the behaviour of these star-forming galaxies at intermediate redshift with high quality spectra. We ...

  4. Organic and chemical manure of the bean (Phaseolus vulgaris) in alluvial soils of intermediate climate

    International Nuclear Information System (INIS)

    With the purpose to evaluate the effect on bean production ICA CITARA variety, four sources of organic matter (hen manure, pig manure, cow manure, and earthworm manure) in four doses 280,500 y 1.000 kg/ha with the same doses of chemical fertilization, were evaluated the experiment was carried out at Tulio Ospina Research Center, located at Bello (Antioquia) of medium climate with 1.320 m.s.n.m. This was established using an alluvial soil (Tropofluvent), frenk, with low contents of organic, matter (2,2%), phosphorus (10 ppm), and potassium (0,10 meq/l00 g). the results, after six consecutive harvests on the same plots, showed highly significative differences among treatments. The highest yield (1.836 kg/ha) was obtained when to the chemical fertilization (300 kg of 10-30-10) was added with 250 kg/ha of hen manure, followed by the application of 100 kg/ha, of cow manure (1.812 kg/ha). Chemical fertilization without organic matter produced 1.640 kg/ha of bean, which was very similar to the addition of 1.000 kg/ha of cow manure and earthworm manure with yields of 1.688 kg/ha and 1.635 kg/ha respectively

  5. Chemical composition of intermediate mass stars members of the M6 (NGC 6405) open cluster

    CERN Document Server

    Kılıçoğlu, Tolgahan; Richer, Jacques; Fossati, Luca; Albayrak, Berahitdin

    2015-01-01

    We present here the first abundance analysis of 44 late B, A and F-type members of the young open cluster M6 (NGC 6405, age about 75 Myrs). Spectra, covering the 4500 to 5800 \\AA{} wavelength range, were obtained using the FLAMES/GIRAFFE spectrograph attached to the ESO Very Large Telescopes (VLT). We determined the atmospheric parameters using calibrations of the Geneva photometry and by adjusting the $H_{\\beta}$ profiles to synthetic ones. The abundances of up to 20 chemical elements, were derived for 19 late B, 16 A and 9 F stars by iteratively adjusting synthetic spectra to the observations. We also derived a mean cluster metallicity of $\\mathrm{[Fe/H]=0.07\\pm0.03}$ dex from the iron abundances of the F-type stars. We find that, for most chemical elements, the normal late B and A-type stars exhibit larger star-to-star abundance variations than the F-type stars do probably because of the faster rotation of the B and A stars. The abundances of C, O, Mg, Si and Sc appear to be anticorrelated to that of Fe, w...

  6. The effects of adding lactic acid bacteria and cellulase in oil palm (Elais guineensis Jacq.) frond silages on fermentation quality, chemical composition and in vitro digestibility

    NARCIS (Netherlands)

    Ebrahimi, Mahdi; Rajion, Mohamed Ali; Goh, Yong Meng; Farjam, Abdoreza Soleimani; Sazili, Awis Qurni; Schonewille, Jan Thomas

    2014-01-01

    The main objective of the current study was to evaluate whether oil palm frond (OPF) can be successfully ensiled without or with the additives cellulase or lactic acid bacteria (LAB). Thus, fresh OPF was ensiled either without additives or with cellulase or LAB or their combination. Ensiling was car

  7. Significant thermal energy reduction in lactic acid production process

    International Nuclear Information System (INIS)

    Lactic acid is widely used as a raw material for the production of biodegradable polymers and in food, chemical and pharmaceutical industries. The global market for lactic acid is expected to reach 259 thousand metric tons by the year 2012. For batch production of lactic acid, the traditional process includes the following steps: (i) esterification of impure lactic acid with methanol in a batch reactor to obtain methyl lactate (ester), (ii) separation of the ester in a batch distillation, (iii) hydrolysis of the ester with water in a batch reactor to produce lactic acid and (iv) separation of lactic acid (in high purity) in a batch distillation. Batch reactive distillation combines the benefit of both batch reactor and batch distillation and enhances conversion and productivity (Taylor and Krishna, 2000 ; Mujtaba and Macchietto, 1997 ). Therefore, the first and the last two steps of the lactic acid production process can be combined together in batch reactive distillation () processes. However, distillation (batch or continuous) is an energy intensive process and consumes large amount of thermal energy (via steam). This paper highlights how significant (over 50%) reduction in thermal energy consumption can be achieved for lactic acid production process by carefully controlling the reflux ratio but without compromising the product specification. In this paper, only the simultaneous hydrolysis of methyl lactate ester and the separation of lactic acid using batch reactive distillation is considered.

  8. Lactic acid test

    Science.gov (United States)

    ... test is most often done to diagnose lactic acidosis . Normal Results 4.5 to 19.8 mg/ ... PA: Elsevier Saunders; 2016:chap 118. Read More Acidosis Aerobic Anaerobic Heart failure - overview Hepatic Metabolism Muscle ...

  9. Determination of Ascorbic Acid Using a New Oscillating chemical System of Lactic Acid—Acetone—BrO3— —Mn2 —H2SO4

    Institute of Scientific and Technical Information of China (English)

    杨树涛; 林智信; 蔡汝秀; 甘南琴

    2002-01-01

    Analyte pulse perturbation(APP)technique was applied to the study of the perturbation of ascorbic acid (AA) on the lactic acid-acetone-BrO3- -Mn2 -H2SO4 oscillating reaction,and AA was determined using this new oscillating chemical system.Influence of experimental variables was investigated.The linear range lies between 5.0×10-7 - 5.5×10-5mol/L,and the precision and throughput were quite good (2.43?as RSD),and 8-10 samples/h,respcetively).This method was applied to the determination of real smples and the results were satisfactory.Some aspects of the potential mechanism of action of AA on the oscillating systems are discussed.

  10. Modelling the effect of ascorbic acid, sodium metabisulphite and sodium chloride on the kinetic responses of lactic acid bacteria and yeasts in table olive storage using a specifically implemented Quasi-chemical primary model.

    Science.gov (United States)

    Echevarria, R; Bautista-Gallego, J; Arroyo-López, F N; Garrido-Fernández, A

    2010-04-15

    The goal of this work was to apply the Quasi-chemical primary model (a system of four ordinary differential equations that derives from a hypothetical four-step chemical mechanism involving an antagonistic metabolite) in the study of the evolution of yeast and lactic acid bacteria populations during the storage of Manzanilla-Aloreña table olives subjected to different mixtures of ascorbic acid, sodium metabisulphite and NaCl. Firstly, the Quasi-chemical model was applied to microbial count data to estimate the growth-decay biological parameters. The model accurately described the evolution of both populations during storage, providing detailed information on the microbial behaviour. Secondly, these parameters were used as responses and analysed according to a mixture design experiment (secondary model). The contour lines of the corresponding response surfaces clearly disclosed the relationships between growth and environmental conditions, showing the stimulating and inhibitory effect of ascorbic acid and sodium metabisulphite, respectively, on both populations of microorganisms. This work opens new possibilities for the potential use of the Quasi-chemical primary model in the study of table olive fermentations. PMID:20185187

  11. Spectroscopic studies of neutral and chemically oxidized species of β-carotene, lycopene and norbixin in CH{sub 2}Cl{sub 2}: Fluorescence from intermediate compounds

    Energy Technology Data Exchange (ETDEWEB)

    Alwis, D.D.D.H [Department of Chemistry, The Open University of Sri Lanka, Nawala (Sri Lanka); Department of Chemistry, University of Sri Jayewardenepura, Nugegoda (Sri Lanka); Chandrika, U.G. [Department of Biochemistry, University of Sri Jayewardenepura, Nugegoda (Sri Lanka); Jayaweera, P.M., E-mail: pradeep@sjp.ac.lk [Department of Chemistry, University of Sri Jayewardenepura, Nugegoda (Sri Lanka)

    2015-02-15

    Radical cations, dications and oxidized intermediate species of three carotenoids, namely, β-carotene, lycopene and norbixin, were generated in CH{sub 2}Cl{sub 2} solutions via chemical oxidation using anhydrous FeCl{sub 3}. UV–vis, fluorescence and fluorescence-excitation spectroscopic studies were performed to understand and compare the nature of intermediate species generated during the chemical oxidation process and subsequent degradation. The intense emission observed at 550 nm can be assigned to the S{sub 2}→S{sub 0} (1{sup 1}B{sub u}→1{sup 1}A{sub g}) transition of the carotenoid molecules. The 350 nm excitation during the oxidation process for β-carotene, lycopene and norbixin exhibit intense fluorescence peaks at 492 nm, 493 nm and 500 nm, respectively. These peaks are assigned to intermediate peroxy/epoxy compounds of the three molecules that are formed with molecular oxygen prior to the formation of oxidized short-chain stable compounds. - Highlights: • Fluorescence and UV–vis studies on β-carotene, lycopene and norbixin. • Oxidation, induced by FeCl{sub 3} in CH{sub 2}Cl{sub 2} shows blue shifted fluorescence peaks. • Fluorescence peaks were assigned to intermediate peroxy/epoxy forms of carotenoids. • The D0→D3 transition of radical cations are observed in the near IR region.

  12. Review of the microbiological, chemical and radiolytic degradation of organic material likely to be present in intermediate level and low level radioactive wastes

    International Nuclear Information System (INIS)

    A review has been made of the microbiological, chemical and radiolytic degradation of the solid organic materials likely to be present in intermediate-level and low-level radioactive wastes. Possible interactions between the three routes for degradation are also discussed. Attention is focussed on the generation of water-soluble degradation products which may form complexes with radioelements. The effects of complexation on radioelement solubility and sorption are considered. Recommendations are made for areas of further research. (author)

  13. Identification of the Chemical Bonding Prompting Adhesion of a-C:H Thin Films on Ferrous Alloy Intermediated by a SiCx:H Buffer Layer.

    Science.gov (United States)

    Cemin, F; Bim, L T; Leidens, L M; Morales, M; Baumvol, I J R; Alvarez, F; Figueroa, C A

    2015-07-29

    Amorphous carbon (a-C) and several related materials (DLCs) may have ultralow friction coefficients that can be used for saving-energy applications. However, poor chemical bonding of a-C/DLC films on metallic alloys is expected, due to the stability of carbon-carbon bonds. Silicon-based intermediate layers are employed to enhance the adherence of a-C:H films on ferrous alloys, although the role of such buffer layers is not yet fully understood in chemical terms. The chemical bonding of a-C:H thin films on ferrous alloy intermediated by a nanometric SiCx:H buffer layer was analyzed by X-ray photoelectron spectroscopy (XPS). The chemical profile was inspected by glow discharge optical emission spectroscopy (GDOES), and the chemical structure was evaluated by Raman and Fourier transform infrared spectroscopy techniques. The nature of adhesion is discussed by analyzing the chemical bonding at the interfaces of the a-C:H/SiCx:H/ferrous alloy sandwich structure. The adhesion phenomenon is ascribed to specifically chemical bonding character at the buffer layer. Whereas carbon-carbon (C-C) and carbon-silicon (C-Si) bonds are formed at the outermost interface, the innermost interface is constituted mainly by silicon-iron (Si-Fe) bonds. The oxygen presence degrades the adhesion up to totally delaminate the a-C:H thin films. The SiCx:H deposition temperature determines the type of chemical bonding and the amount of oxygen contained in the buffer layer. PMID:26135943

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    The ability of lactic acid bacteria to produce lactic acid from various sugars plays an important role in food fermentations. Lactic acid is derived from pyruvate, the end product of glycolysis and thus a fast lactic acid production rate requires a high glycolytic flux. In addition to lactic acid......, alternative end products - ethanol, acetic acid and formic acid - are formed by many species. The central role of glycolysis in lactic acid bacteria has provoked numerous studies aiming at identifying potential bottleneck(s) since knowledge about flux control could be important not only for optimizing food...... fermentation processes, but also for novel applications of lactic acid bacteria, such as cell factories for the production of green fuels and chemicals. With respect to the control and regulation of the fermentation mode, some progress has been made, but the question of which component(s) control the main...

  15. Capillary electrophoresis as a tool for evaluating lactic acid production from sorghum

    Science.gov (United States)

    Interest in the use of renewable resources for the production of bio-industrial chemicals and fuels is increasing. One industrial chemical that can be produced from renewable resources is lactic acid. Lactic acid is used in the food industry as a flavor compound, preservative, and to acidify produ...

  16. Lactic acid and lactates

    NARCIS (Netherlands)

    Schreurs, V.V.A.M.

    2010-01-01

    This review aims to integrate the present state of knowledge on lactate metabolism in human and mammalian physiology as far as it could be subject to nutritional interventions. An integrated view on the nutritional, metabolic and physiological aspects of lactic acid and lactates might open a perspec

  17. An integrated bioconversion process for the production of L-lactic acid from starchy feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, S.P.; Moon, S.H.

    1997-07-01

    The potential market for lactic acid as the feedstock for biodegradable polymers, oxygenated chemicals, and specialty chemicals is significant. L-lactic acid is often the desired enantiomer for such applications. However, stereospecific lactobacilli do not metabolize starch efficiently. In this work, Argonne researchers have developed a process to convert starchy feedstocks into L-lactic acid. The processing steps include starch recovery, continuous liquefaction, and simultaneous saccharification and fermentation. Over 100 g/L of lactic acid was produced in less than 48 h. The optical purity of the product was greater than 95%. This process has potential economical advantages over the conventional process.

  18. Food preservation using antifungal lactic acid bacteria

    OpenAIRE

    Crowley, Sarah Catherine Mary

    2013-01-01

    Fungal spoilage of food and feed prevails as a major problem for the food industry. The use antifungal-producing lactic acid bacteria (LAB) may represent a safer, natural alternative to the use of chemical preservatives in foods. A large scale screen was undertaken to identify a variety of LAB with antifungal properties from plant, animal and human sources. A total of 6,720 LAB colonies were isolated and screened for antifungal activity against the indicator Penicillium expansum. 94 broad-spe...

  19. Betaine and Beet Molasses Enhance L-Lactic Acid Production by Bacillus coagulans

    OpenAIRE

    Ke Xu; Ping Xu

    2014-01-01

    Lactic acid is an important chemical with various industrial applications, and it can be efficiently produced by fermentation, in which Bacillus coagulans strains present excellent performance. Betaine can promote lactic acid fermentation as an effective osmoprotectant. Here, positive effect of betaine on fermentation by B. coagulans is revealed. Betaine could enhance lactic acid production by protecting l-LDH activity and cell growth from osmotic inhibition, especially under high glucose con...

  20. l-(+)-Lactic acid production by Lactobacillus rhamnosus B103 from dairy industry waste

    OpenAIRE

    Bernardo, Marcela Piassi; Coelho, Luciana Fontes; Sass, Daiane Cristina; Contiero, Jonas

    2016-01-01

    Lactic acid, which can be obtained through fermentation, is an interesting compound because it can be utilized in different fields, such as in the food, pharmaceutical and chemical industries as a bio-based molecule for bio-refinery. In addition, lactic acid has recently gained more interest due to the possibility of manufacturing poly(lactic acid), a green polymer that can replace petroleum-derived plastics and be applied in medicine for the regeneration of tissues and in sutures, repairs an...

  1. The application of a coupled chemical transport model in a trial assessment of deep disposal of low and intermediate level radioactive waste

    International Nuclear Information System (INIS)

    A series of trial assessments are being undertaken within the United Kingdom to rehearse procedures for post-closure radiological risk analysis of low and intermediate level radioactive waste disposal sites. These trial studies draw together workers from a variety of scientific disciplines allowing simultaneous rather than isolated development of assessment procedures. This paper illustrates the use of chemical codes and data within a probabilistic risk assessment framework through a demonstration exercise performed on a hypothetical repository located beneath Harwell, Oxfordshire. The implications for risk assessment practices reliant on the assumption of conservative parameters are highlighted by comparison with a more mechanistic approach which takes into account competitive effects

  2. LACTIC ACID BACTERIA: PROBIOTIC APPLICATIONS

    OpenAIRE

    NEENA GARG

    2015-01-01

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

  3. Computational analysis of the mechanism of chemical reactions in terms of reaction phases: hidden intermediates and hidden transition States.

    Science.gov (United States)

    Kraka, Elfi; Cremer, Dieter

    2010-05-18

    Computational approaches to understanding chemical reaction mechanisms generally begin by establishing the relative energies of the starting materials, transition state, and products, that is, the stationary points on the potential energy surface of the reaction complex. Examining the intervening species via the intrinsic reaction coordinate (IRC) offers further insight into the fate of the reactants by delineating, step-by-step, the energetics involved along the reaction path between the stationary states. For a detailed analysis of the mechanism and dynamics of a chemical reaction, the reaction path Hamiltonian (RPH) and the united reaction valley approach (URVA) are an efficient combination. The chemical conversion of the reaction complex is reflected by the changes in the reaction path direction t(s) and reaction path curvature k(s), both expressed as a function of the path length s. This information can be used to partition the reaction path, and by this the reaction mechanism, of a chemical reaction into reaction phases describing chemically relevant changes of the reaction complex: (i) a contact phase characterized by van der Waals interactions, (ii) a preparation phase, in which the reactants prepare for the chemical processes, (iii) one or more transition state phases, in which the chemical processes of bond cleavage and bond formation take place, (iv) a product adjustment phase, and (v) a separation phase. In this Account, we examine mechanistic analysis with URVA in detail, focusing on recent theoretical insights (with a variety of reaction types) from our laboratories. Through the utilization of the concept of localized adiabatic vibrational modes that are associated with the internal coordinates, q(n)(s), of the reaction complex, the chemical character of each reaction phase can be identified via the adiabatic curvature coupling coefficients, A(n,s)(s). These quantities reveal whether a local adiabatic vibrational mode supports (A(n,s) > 0) or resists

  4. Quantum chemical study of conformational preferences of intermediates and transition states in the alkaline hydrolysis of dimethyl phosphate

    International Nuclear Information System (INIS)

    The phosphate diester is a basic structure in DNA and RNA. The mechanism of phosphate diester hydrolysis is important for understanding the decomposition reactions of nucleic acids. In this study, we have explored the reaction pathway of alkaline hydrolysis of dimethyl phosphate, which is the simplest phosphate diester, with a hydroxide ion. Since the conformations of the intermediates and transition states reportedly influence the reaction mechanism of transacylation of methyl acetate with methoxide, we considered the conformational preferences on the alkaline hydrolysis of dimethyl phosphate, by using the most stable conformer as a reactant. Upon the reaction with hydroxide, a concerted reaction pathway was obtained in the gas phase, whereas a stepwise reaction pathway was obtained in water. As compared to the earlier study, our computation shows more stable conformations in the hydrolysis reactions than the previous study

  5. New trends and challenges in lactic acid production on renewable biomass

    OpenAIRE

    Đukić-Vuković Aleksandra J.; Mojović Ljiljana V.; Pejin Dušanka; Vukašinović-Sekulić Maja; Rakin Marica; Nikolić Svetlana; Pejin Jelena

    2011-01-01

    Lactic acid is a relatively cheap chemical with a wide range of applications: as a preservative and acidifying agent in food and dairy industry, a monomer for biodegradable poly-lactide polymers (PLA) in pharmaceutical industry, precursor and chemical feedstock for chemical, textile and leather industries. Traditional raw materials for fermentative production of lactic acid, refined sugars, are now being replaced with starch from corn, rice and other crops for industrial production, wit...

  6. The hot core towards the intermediate mass protostar NGC7129 FIRS 2: Chemical similarities with Orion KL

    CERN Document Server

    Fuente, A; Caselli, P; McCoey, C; Johnstone, D; Fich, M; van Kempen, T; Palau, Aina; Yildiz, U A; Tercero, B; López, A

    2014-01-01

    NGC 7129 FIRS 2 (hereafter FIRS 2) is an intermediate-mass (2 to 8 Msun) protostar located at a distance of 1250 pc. High spatial resolution observations are required to resolve the hot core at its center. We present a molecular survey from 218200 MHz to 221800 MHz carried out with the IRAM Plateau de Bure Interferometer. These observations were complemented with a long integration single-dish spectrum taken with the IRAM 30m telescope. We used a Local Thermodynamic Equilibrium (LTE) single temperature code to model the whole dataset. The interferometric spectrum is crowded with a total of ~300 lines from which a few dozens remain unidentified yet. The spectrum has been modeled with a total of 20 species and their isomers, isotopologues and deuterated compounds. Complex molecules like methyl formate (CH3OCHO), ethanol (CH3CH2OH), glycolaldehyde (CH2OHCHO), acetone (CH3COCH3), dimethyl ether (CH3OCH3), ethyl cyanide (CH3CH2CN) and the aGg' conformer of ethylene glycol (aGg'-(CH2OH)_2) are among the detected sp...

  7. Chemical modification of poly (lactic acid) and its research progress%聚乳酸的化学改性及研究进展

    Institute of Scientific and Technical Information of China (English)

    唐志民; 马新宾

    2016-01-01

    综述了PLA化学改性的主要方法及研究发展现状,主要包括缩合共聚改性和开环共聚改性,并重点概述了PLA的接枝改性研究现状,对各种改性方法的改性效果进行了论述.%The main modification methods of PLA including condensation copolymerization and ring-opening copolymerization,and their research progress are reviewed.The chemical grafting modification of PLA are highlighted.The modification effects of each method are also compared.

  8. Chemical compatibility and properties of suspension plasma-sprayed SrTiO3-based anodes for intermediate-temperature solid oxide fuel cells

    Science.gov (United States)

    Zhang, Shan-Lin; Li, Cheng-Xin; Li, Chang-Jiu

    2014-10-01

    La-doped strontium titanate (LST) is a promising, redox-stable perovskite material for direct hydrocarbon oxidation anodes in intermediate-temperature solid oxide fuel cells (IT-SOFCs). In this study, nano-sized LST and Sm-doped ceria (SDC) powders are produced by the sol-gel and glycine-nitrate processes, respectively. The chemical compatibility between LST and electrolyte materials is studied. A LST-SDC composite anode is prepared by suspension plasma spraying (SPS). The effects of annealing conditions on the phase structure, microstructure, and chemical stability of the LST-SDC composite anode are investigated. The results indicate that the suspension plasma-sprayed LST-SDC anode has the same phase structure as the original powders. LST exhibits a good chemical compatibility with SDC and Mg/Sr-doped lanthanum gallate (LSGM). The anode has a porosity of ∼40% with a finely porous structure that provides high gas permeability and a long three-phase boundary for the anode reaction. Single cells assembled with the LST-SDC anode, La0.8Sr0.2Ga0.8Mg0.2O3 electrolyte, and La0.8Sr0.2CoO3-SDC cathode show a good performance at 650-800 °C. The annealing reduces the impedances due to the enhancement in the bonding between the particles in the anode and interface of anode and LSGM electrolyte, thus improving the output performance of the cell.

  9. 21 CFR 184.1061 - Lactic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Lactic acid. 184.1061 Section 184.1061 Food and... Substances Affirmed as GRAS § 184.1061 Lactic acid. (a) Lactic acid (C3H6O3, CAS Reg. Nos.: dl mixture, 598... hydrogen cyanide and subsequent hydrolysis to lactic acid. (b) The ingredient meets the specifications...

  10. CARACTERIZAÇÃO FÍSICO-QUÍMICA, HISTOLÓGICA E VIABILIDADE DE BACTÉRIAS LÁCTICAS EM IOGURTES COM FRUTAS PHYSICO CHEMICAL, HISTOLOGYCAL AND VIABILITY OF LACTIC BACTERIA IN YOGURTS CONTAINING FRUIT

    Directory of Open Access Journals (Sweden)

    Maria Auxiliadora de Brito RODAS

    2001-12-01

    Full Text Available Foram analisadas 136 amostras de iogurtes com frutas de 8 marcas diferentes, adquiridas em supermercados da cidade de São Paulo, no período de 1997 a 1998, com a finalidade de caracterizá-los quanto aos parâmetros físico-químicos, identificação histológica das frutas adicionadas e viabilidade de bactérias lácticas viáveis. Nas avaliações foram utilizadas metodologias oficiais e recomendações. Quanto aos parâmetros físico-químicos, os resultados obtidos das variações médias e desvio padrão foram os seguintes: pH (4,01±0,11; substâncias voláteis (77,91%±1,85; resíduo mineral fixo (0,68%±0,10; lipídios (1,95%±0,65; proteínas (2,95%±0,46; carboidratos totais (15,89%±1,44 e valor calórico (93±9. Das 136 amostras analisadas, detectou-se fraude em 5,8% por não apresentarem as frutas indicadas na rotulagem, em 40,4% por apresentarem elementos histológicos de vegetais não discriminados pelos fabricantes e 44,1% por conterem fungos filamentosos, indicativo de utilização inadequada de matéria-prima. Quanto à viabilidade das bactérias lácticas, verificou-se a positividade da fermentação em até a diluição 10-7 em todas as amostras, mesmo naquelas que apresentavam apenas cocos Gram-positivos. Na contagem individual de estreptococos e de lactobacilos constituintes da microbiota láctica, 31,73% das amostras apresentaram quantidade igual ou superior a 10(7UFC/mL, limite mínimo indicado pela Recomendação Mercosul nº 31/97.One hundred and thirty six (136 samples of yogurts with fruits from eight different brands, acquired in supermarkets of São Paulo, in the period betwen 1997 and 1998, have been analysed aiming to characterise them for physico-chemical parameters, histologycal identification of added fruits and viability of lactic bacteria. On valuation official methodologies and recommendations were used . Concerning the physico-chemical parameters, the obtained results for medium verification and standard

  11. l-(+)-Lactic acid production by Lactobacillus rhamnosus B103 from dairy industry waste.

    Science.gov (United States)

    Bernardo, Marcela Piassi; Coelho, Luciana Fontes; Sass, Daiane Cristina; Contiero, Jonas

    2016-01-01

    Lactic acid, which can be obtained through fermentation, is an interesting compound because it can be utilized in different fields, such as in the food, pharmaceutical and chemical industries as a bio-based molecule for bio-refinery. In addition, lactic acid has recently gained more interest due to the possibility of manufacturing poly(lactic acid), a green polymer that can replace petroleum-derived plastics and be applied in medicine for the regeneration of tissues and in sutures, repairs and implants. One of the great advantages of fermentation is the possibility of using agribusiness wastes to obtain optically pure lactic acid. The conventional batch process of fermentation has some disadvantages such as inhibition by the substrate or the final product. To avoid these problems, this study was focused on improving the production of lactic acid through different feeding strategies using whey, a residue of agribusiness. The downstream process is a significant bottleneck because cost-effective methods of producing high-purity lactic acid are lacking. Thus, the investigation of different methods for the purification of lactic acid was one of the aims of this work. The pH-stat strategy showed the maximum production of lactic acid of 143.7g/L. Following purification of the lactic acid sample, recovery of reducing sugars and protein and color removal were 0.28%, 100% and 100%, respectively. PMID:27266630

  12. Make use of lactic acid bacteria in biomass to biofuel

    Science.gov (United States)

    Lactic acid bacteria (LAB) have been widely used in dairy fermentations, nutraceuticals, and probiotic/prebiotic applications. Selected strains from the LAB could potentially be used as microbial catalysts for production of fuels and chemicals from lignocellulosic biomass. The unique traits of lac...

  13. Chemical study of intermediate-mass (IM) Class 0 protostars. CO depletion and N2H+ deuteration

    CERN Document Server

    Alonso-Albi, T; Crimier, N; Caselli, P; Ceccarelli, C; Johnstone, D; Planesas, P; Rizzo, J R; Wyrowski, F; Tafalla, M; Lefloch, B; Maret, S; Dominik, C

    2010-01-01

    We are carrying out a physical and chemical study of the protostellar envelopes in a representative sample of IM Class 0 protostars. In our first paper (Crimier et al. 2010), we determined the physical structure (Density-Temperature radial profiles) of the protostellar envelopes. Here, we study the CO depletion and N2H+ deuteration. We observed the millimeter lines of C18O, C17O, N2H+ and N2D+ toward the protostars using the IRAM 30m telescope. Based on these observations, we derived the C18O, N2H+ and N2D+ radial abundance profiles across their envelopes using a radiative transfer code. In addition, we modeled the chemistry of the protostellar envelopes. All the C18O 1-0 maps are well fit assuming that the C18O abundance decreases inwards within the protostellar envelope until the gas and dust reach the CO evaporation temperature, 20-25K, where the CO is released back to the gas phase. The N2H+ deuterium fractionation in Class 0 IMs is [N2D+]/[N2H+]=0.005-0.014, two orders of magnitude larger than the elemen...

  14. Direct fermentation of potato starch and potato residues to lactic acid by Geobacillus stearothermophilus under non-sterile conditions

    OpenAIRE

    Smerilli, Marina; Neureiter, Markus; Wurz, Stefan; Haas, Cornelia; Frühauf, Sabine; Fuchs, Werner

    2015-01-01

    BACKGROUND Lactic acid is an important biorefinery platform chemical. The use of thermophilic amylolytic microorganisms to produce lactic acid by fermentation constitutes an efficient strategy to reduce operating costs, including raw materials and sterilization costs. RESULTS A process for the thermophilic production of lactic acid by Geobacillus stearothermophilus directly from potato starch was characterized and optimized. Geobacillus stearothermophilus DSM 494 was selected out of 12 strain...

  15. EFFECT OF NITROGEN SOURCE AND INITIAL SUGAR CONCENTRATION ON LACTIC ACID FERMENTATION OF PINEAPPLE WASTE USING L.DELBRUECKII

    OpenAIRE

    Abdullah Moch Busairi

    2012-01-01

    The liquid pineapple waste contains mainly sucrose, glucose, fructose and other nutrients. It therefore can potentially be used as carbon source for lactic acid fermentation. The lactic acid is utilised in food technology as pH regulator, microbial preservative, buffering agent and in the chemical industry. Recently, lactic acid has been considered to be an important raw material for production of biodegradable lactate polymer. The experiments were carried out in batch fermentation at anaerob...

  16. Betaine and beet molasses enhance L-lactic acid production by Bacillus coagulans.

    Directory of Open Access Journals (Sweden)

    Ke Xu

    Full Text Available Lactic acid is an important chemical with various industrial applications, and it can be efficiently produced by fermentation, in which Bacillus coagulans strains present excellent performance. Betaine can promote lactic acid fermentation as an effective osmoprotectant. Here, positive effect of betaine on fermentation by B. coagulans is revealed. Betaine could enhance lactic acid production by protecting l-LDH activity and cell growth from osmotic inhibition, especially under high glucose concentrations and with poor organic nitrogen nutrients. The fermentation with 0.05 g/L betaine could produce 17.9% more lactic acid compared to the fermentation without betaine. Beet molasses, which is rich in sucrose and betaine, was utilized in a co-feeding fermentation and raised the productivity by 22%. The efficient lactic acid fermentation by B. coagulans is thus developed by using betaine and beet molasses.

  17. d-lactic acid production from renewable lignocellulosic biomass via genetically modified Lactobacillus plantarum.

    Science.gov (United States)

    Zhang, Yixing; Kumar, Amit; Hardwidge, Philip R; Tanaka, Tsutomu; Kondo, Akihiko; Vadlani, Praveen V

    2016-03-01

    d-lactic acid is of great interest because of increasing demand for biobased poly-lactic acid (PLA). Blending poly-l-lactic acid with poly-d-lactic acid greatly improves PLA's mechanical and physical properties. Corn stover and sorghum stalks treated with 1% sodium hydroxide were investigated as possible substrates for d-lactic acid production by both sequential saccharification and fermentation and simultaneous saccharification and cofermentation (SSCF). A commercial cellulase (Cellic CTec2) was used for hydrolysis of lignocellulosic biomass and an l-lactate-deficient mutant strain Lactobacillus plantarum NCIMB 8826 ldhL1 and its derivative harboring a xylose assimilation plasmid (ΔldhL1-pCU-PxylAB) were used for fermentation. The SSCF process demonstrated the advantage of avoiding feedback inhibition of released sugars from lignocellulosic biomass, thus significantly improving d-lactic acid yield and productivity. d-lactic acid (27.3 g L(-1) ) and productivity (0.75 g L(-1) h(-1) ) was obtained from corn stover and d-lactic acid (22.0 g L(-1) ) and productivity (0.65 g L(-1) h(-1) ) was obtained from sorghum stalks using ΔldhL1-pCU-PxylAB via the SSCF process. The recombinant strain produced a higher concentration of d-lactic acid than the mutant strain by using the xylose present in lignocellulosic biomass. Our findings demonstrate the potential of using renewable lignocellulosic biomass as an alternative to conventional feedstocks with metabolically engineered lactic acid bacteria to produce d-lactic acid. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:271-278, 2016. PMID:26700935

  18. Lactic Acid Bacteria

    Directory of Open Access Journals (Sweden)

    ToddKlaenhammer

    2013-04-01

    Full Text Available Lactic acid bacteria (LAB are a diverse group of Gram-positive bacteria found in a vast array of environments including dairy products and the human gastrointestinal tract. In both niches, surface proteins play a crucial role in mediating interactions with the surrounding environment. The sortase enzyme is responsible for covalently coupling a subset of surface dependent proteins (SDPs to the cell wall of Gram-positive organisms through recognition of a conserved C-terminal LPXTG motif. Genomic sequencing of LAB and annotation has allowed for the identification of sortase and SDPs. Historically, sortase and SDPs were predominately investigated for their role in mediating pathogenesis. Identification of these proteins in LAB has shed light on their important roles in mediating nutrient acquisition through proteinase P as well as positive probiotic attributes including adhesion, mucus barrier function, and immune signaling. Furthermore, sortase expression signals in LAB have been exploited as a means to develop oral vaccines targeted to the gastrointestinal tract. In this review, we examine the collection of studies which evaluate sortase and SDPs in select species of dairy associated and health promoting LAB.

  19. LACTIC ACID BACTERIA: PROBIOTIC APPLICATIONS

    Directory of Open Access Journals (Sweden)

    NEENA GARG

    2015-10-01

    Full Text Available Lactic acid bacteria (LAB is a heterotrophic Gram-positive bacteria which under goes lactic acid fermentations and leads to production of lactic acid as an end product. LAB includes Lactobacillus, Leuconostoc, Pediococcus, Lactococcus and Streptococcus which are grouped together in the family lactobacillaceae. LAB shows numerous antimicrobial activities due to production of antibacterial and antifungal compounds such as organic acids, bacteriocins, diacetyl, hydrogen peroxide and reutrin. LAB are used as starter culture, consortium members and bioprotective agents in food industry that improve food quality, safety and shelf life. A variety of probiotic LAB species are available including Lactobacillus acidophilus, L. bulgaricus, L. lactis, L. plantarum, L. rhamnosus, L. reuteri, L. fermentum, Bifidobacterium longum, B. breve, B. bifidum, B. esselnsis, B. lactis, B. infantis that are currently recommended for development of functional food products with health-promoting capacities.

  20. Preparation of lactic acid bacteria fermented wheat-yoghurt mixtures

    Directory of Open Access Journals (Sweden)

    Michal Magala

    2013-09-01

    Full Text Available Background. Tarhana, a wheat-yoghurt fermented mixture, is considered as a good source of saccharides, proteins, some vitamins and minerals. Moreover, their preparation is inexpensive and lactic acid fermentation offers benefi ts like product preservation, enhancement of nutritive value and sensory properties improvement. The aim of this work was to evaluate changes of some chemical parameters during fermentation of tarhana, when the level of salt and amount of yoghurt used were varied. Some functional and sensory characteristics of the fi nal product were also determined. Material and methods. Chemical analysis included determination of pH, titrable acidity, content of reducing saccharides, lactic, acetic and citric acid. Measured functional properties of tarhana powder were foaming capacity, foam stability, water absorption capacity, oil absorption capacity and emulsifying activity. Tarhana soups samples were evaluated for their sensory characteristics (colour, odor, taste, consistency and overall acceptability. Results. Fermentation of tarhana by lactic acid bacteria and yeasts led to decrease in pH, content of reducing saccharides and citric acid, while titrable acidity and concentration of lactic and acetic acid increased. Determination of functional properties of tarhana powder showed, that salt absence and increased amount of yoghurt in tarhana recipe reduced foaming capacity and oil absorption capacity, whereas foam stability and water absorption capacity were improved. Sensory evaluation of tarhana soups showed that variations in tarhana recipe adversly affected sensory parameters of fi nal products. Conclusion. Variations in tarhana recipe (salt absence, increased proportion of yoghurt led to changes in some chemical parameters (pH, titrable acidity, reducing saccharides, content of lactic, acetic and citric acid. Functional properties were also affected with changed tarhana recipe. Sensory characteristics determination showed, that

  1. 21 CFR 582.1061 - Lactic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Lactic acid. 582.1061 Section 582.1061 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1061 Lactic acid. (a) Product. Lactic acid. (b) Conditions of use. This substance is...

  2. Towards lactic acid bacteria-based biorefineries.

    Science.gov (United States)

    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

  3. Lactic acid production by irradiated Bacillus NF17 and poly-L-lactate biopolymer formation

    International Nuclear Information System (INIS)

    This study was conducted to manipulate the thermo tolerant, lactic acid-producing bacteria, Bacillus coagulans strain NF17, in the production of L-lactic acid and a bio polymer: poly-L-lactate. The bacterial isolate NF17 kept in the culture collection of Khon Kaen University and could tolerate high temperature and produce lactic acid, was employed in this research work. Cell suspension of isolate NF17 was exposed to gamma irradiation at various doses (1-5 KGy). The irradiated survivors were screened on the basis of forming larger colonies and clear zones than the parent strain NF17 when grown on Glucose-Yeast extract-Peptone (GYP) containing CaCO3. We obtained 55 effective isolates which the isolate L5I2-14(5), designated as K14, was chosen together with the parent strain NF17 for fermentation experiments. Each bacterial strain was inoculated into GYP broth and incubated statically at 50oC with daily pH neutralization. After 5 days of incubation, the isolate K14 and NF17 produced 9.71 g/l and 7.42 g/l of L-lactic acid, respectively with a small amount of D-lactic acid. Lactic acid production from sugar cane molasses by batch fermentation of Bacillus Sp. K14 was carried out in a 7 l jar fermentor containing 5 l of fermentation medium. It was found that 20% molasses with the agitation speed of 100 rpm gave the highest yield of lactic acid. Poly-L-lactic acid was chemically polymerized by bulk polymerization process at 140oC under 40 mmHg conditions. We could obtain the off-white polymer in a small amount of powder form. Improvement the yield of poly-L-lactic acid would be achieved by using polyisoprene-g-polyvinyl monomer to separate lactic acid from the fermenting liquid prior to polymerization processes

  4. Financial Intermediation

    OpenAIRE

    Gary Gorton; Andrew Winton

    2002-01-01

    The savings/investment process in capitalist economies is organized around financial intermediation, making them a central institution of economic growth. Financial intermediaries are firms that borrow from consumer/savers and lend to companies that need resources for investment. In contrast, in capital markets investors contract directly with firms, creating marketable securities. The prices of these securities are observable, while financial intermediaries are opaque. Why do financial inter...

  5. Intermediated Trade

    OpenAIRE

    Antras, Pol; Costinot, Arnaud

    2011-01-01

    This paper develops a simple model of international trade with intermediation. We consider an economy with two islands and two types of agents, farmers and traders. Farmers can produce two goods, but in order to sell these goods in centralized (Walrasian) markets, they need to be matched with a trader, and this entails costly search. In the absence of search frictions, our model reduces to a standard Ricardian model of trade. We use this simple model to contrast the implications of changes in...

  6. ISOLATION AND IDENTIFICATION OF LACTIC ACID PRODUCING BACTERIA FROM CAMEL MILK

    OpenAIRE

    Toqeer Ahmad, Rashida Kanwal, Izhar Hussain Athar1, Najam Ayub

    2002-01-01

    Lactic acid bacteria (LAB) were isolated from camel milk by culturing the camel milk on specific media and pure culture was obtained by sub culturing. Purification of culture was confirmed by Gram's staining and identified by different bio-chemical tests. Camel milk contains lactic acid producing bacteria including Strpptococci such as S. cremoris and S. lactis and Lactobacilli such as L. acidophilus L. acidophilus grows more rapidly in camel milk than others as its growth is supported by cam...

  7. Engineering robust lactic acid bacteria

    NARCIS (Netherlands)

    Bron, P.A.; Bokhorst-van de Veen, van H.; Wels, M.; Kleerebezem, M.

    2011-01-01

    For centuries, lactic acid bacteria (LAB) have been industrially exploited as starter cultures in the fermentation of foods and feeds for their spoilage-preventing and flavor-enhancing characteristics. More recently, the health-promoting effects of LAB on the consumer have been widely acknowledged,

  8. Intermediate Images

    OpenAIRE

    Paech Joachim

    2014-01-01

    Starting from a definition of the word ‘picture’ as a real-world object that shows other objects on its surface as a representation of its image, I propose that the intermediality of pictures of all kinds is only possible through their images, after they have been separated from their material basis or foundation (for example, a painting in its physical reality can never be directly connected with a movie). In all technical reproductions of images, such as printing processes, an image is take...

  9. Production of high optical purity l-lactic acid from waste activated sludge by supplementing carbohydrate: effect of temperature and pretreatment time.

    Science.gov (United States)

    Jian, Qiwei; Li, Xiang; Chen, Yinguang; Liu, Yanan; Pan, Yin

    2016-10-01

    It has been widely accepted that the most environmentally beneficial way to treat waste activated sludge (WAS), the byproduct of municipal wastewater treatment plant, is to recover the valuable organic acid. However, the bio-conversion of lactic acid, one of the high added-value chemical, is seldom reported from WAS fermentation. In this paper, l-lactic acid was observed dominant in the WAS fermentation liquid with carbohydrate addition at ambient temperature. Furthermore, the effect of temperature on l-lactic acid and d-lactic acid production was fully discussed: two isomers were rapidly produced and consumed up in one day at mesophilic condition; and almost optically pure l-lactic acid was generated at thermophilic condition, yet time-consuming with yield of l-lactic acid enhancing by 52.9% compared to that at ambient temperature. The study mechanism showed that mesophilic condition was optimal for both production and consumption of l-lactic acid and d-lactic acid, while consumption of l-lactic acid and production of d-lactic acid were severely inhibited at thermophilic condition. Therefore, by maintaining thermophilic for 4 h in advance and subsequently fermenting mesophilic for 34 h, the concentration of l-lactic acid with optical activity of 98.3% was improved to 16.6 ± 0.5 g COD/L at a high specific efficiency of 0.6097/d. PMID:26878176

  10. Influence of lactic acid on the two-phase anaerobic digestion of kitchen wastes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Bo; CAI Wei-min; HE Pin-jing

    2007-01-01

    To evaluate the influence of lactic acid on the methanogenesis, anaerobic digestion of kitchen wastes was firstly conducted in a two-phase anaerobic digestion process, and performance of two digesters fed with lactic acid and glucose was subsequently compared.The results showed that the lactic acid was the main fermentation products of hydrolysis-acidification stage in the two-phase anaerobic digestion process for kitchen wastes. The lactic acid concentration constituted approximately 50% of the chemical oxygen demand (COD) concentration in the hydrolysis-acidification liquid. The maximum organic loading rate was lower in the digester fed with lactic acid than that fed with glucose. Volatile fatty acids (VFAs) and COD removal were deteriorated in the methanogenic reactor fed with to the high concentration of lactic acid fed. It could be concluded that avoiding the presence of the lactic acid is necessary in the hydrolysis-acidification process for the improvement of the two-phase anaerobic digestion process of kitchen wastes.

  11. Effect of 82% Lactic Acid in Treatment of Melasma

    OpenAIRE

    Singh, Rashmi; Goyal, Sapna; Ahmed, Qazi Rais; Gupta, Narendra; Singh, Sujata

    2014-01-01

    Melasma is an acquired, chronic, and symmetrical hypermelanosis, characterized by brown patches of variable darkness on sun exposed areas of body. There are numerous modalities of treatment currently in use for this disease, of which the chemical peeling is very commonly used. Therefore, the present work was done to see the effect of 82% lactic acid peel in the treatment of melasma. A total number of 20 patients of either sex attending the OPD of dermatology department with clinically evident...

  12. Naturally Occurring Lactic Acid Bacteria Isolated from Tomato Pomace Silage

    OpenAIRE

    Wu, Jing-Jing; Du, Rui-ping; Gao, Min; Sui, Yao-qiang; Xiu, Lei; Wang, Xiao

    2014-01-01

    Silage making has become a significant method of forage conservation worldwide. To determine how tomato pomace (TP) may be used effectively as animal feed, it was ensilaged for 90 days and microbiology counts, fermentation characteristics and chemical composition of tomato pomace silage (TPS) were evaluated at the 30th, 60th, and 90th days, respectively. In addition, 103 lactic acid bacteria were isolated from TPS. Based on the phenotypic and chemotaxonomic characteristics, 16S rDNA sequence ...

  13. Ion-exchange Resin Catalyzed Esterification of Lactic Acid with Isopropanol: a Kinetic Study

    Directory of Open Access Journals (Sweden)

    Amrit P. Toor

    2011-05-01

    Full Text Available The kinetic behavior of esterification of lactic acid with isopropanol over an acidic cation exchange resin, Amberlyst 15, was studied under isothermal condition. Isopropyl lactate synthesized in this reaction is an important pharmaceutical intermediate. The experiments were carried out in a stirred batch reactor in the temperature range of 323.15 to 353.15 K. The effect of various parameters such as temperature, molar ratio and catalyst loading was studied. Variation in parameters on rate of reaction demonstrated that the reaction was intrinsically controlled. Kinetic modeling was performed using Eley-Rideal model which acceptably fits the experimental data. The activation energy was found to be 22.007 kJ/mol and frequency factor was 0.036809 l2 g-1 mol-1 min-1 for forward reaction. The value of entropy for the forward reaction was found to be 182.317 J K-1 mol-1 . © 2011 BCREC UNDIP. All rights reserved(Received: 19th January 2011, Revised: 16th March 2011; Accepted: 16th March 2011[How to Cite: A.P. Toor, M. Sharma, S. Thakur, and R. K. Wanchoo. (2011. Ion-exchange Resin Catalyzed Esterification of Lactic Acid with Isopropanol: a Kinetic Study. Bulletin of Chemical Reaction Engineering and Catalysis, 6(1: 39-45. doi:10.9767/bcrec.6.1.791.39-45][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.6.1.791.39-45 || or local:  http://ejournal.undip.ac.id/index.php/bcrec/article/view/791 ] | View in  

  14. Intermediate Images

    Directory of Open Access Journals (Sweden)

    Paech Joachim

    2014-12-01

    Full Text Available Starting from a definition of the word ‘picture’ as a real-world object that shows other objects on its surface as a representation of its image, I propose that the intermediality of pictures of all kinds is only possible through their images, after they have been separated from their material basis or foundation (for example, a painting in its physical reality can never be directly connected with a movie. In all technical reproductions of images, such as printing processes, an image is taken from a negative matrix in order to realize multiple prints of the same representation. The most effective model of this procedure is photography: photographic images can easily be connected with their media forms to produce other, more complex forms, such as magazines, printed books, or films. Intermediate images in the form of matrices - sometimes transparent (e.g. in the light beam of a film projection, sometimes opaque - are required to transform one pictorial media form into another. Finally, for the digital matrix-image, there is no longer any difference between the matrix and the image: the matrix has become its own image, which can be linked to all other media forms.

  15. 21 CFR 862.1450 - Lactic acid test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Lactic acid test system. 862.1450 Section 862.1450....1450 Lactic acid test system. (a) Identification. A lactic acid test system is a device intended to measure lactic acid in whole blood and plasma. Lactic acid measurements that evaluate the acid-base...

  16. Intermediate uveitis

    Directory of Open Access Journals (Sweden)

    Babu B

    2010-01-01

    Full Text Available Intermediate uveitis (IU is described as inflammation in the anterior vitreous, ciliary body and the peripheral retina. In the Standardization of Uveitis Nomenclature (SUN working group′s international workshop for reporting clinical data the consensus reached was that the term IU should be used for that subset of uveitis where the vitreous is the major site of the inflammation and if there is an associated infection (for example, Lyme disease or systemic disease (for example, sarcoidosis. The diagnostic term pars planitis should be used only for that subset of IU where there is snow bank or snowball formation occurring in the absence of an associated infection or systemic disease (that is, "idiopathic". This article discusses the clinical features, etiology, pathogenesis, investigations and treatment of IU.

  17. Prediction of in vivo potential for metabolic activation of drugs into chemically reactive intermediate: correlation of in vitro and in vivo generation of reactive intermediates and in vitro glutathione conjugate formation in rats and humans.

    Science.gov (United States)

    Masubuchi, Noriko; Makino, Chie; Murayama, Nobuyuki

    2007-03-01

    The covalent binding of reactive intermediates to macromolecules might have potential involvement in severe adverse drug reactions. Thus, quantification of reactive metabolites is necessary during the early stage of drug discovery to avoid serious toxicity. In this study, the relationship between covalent binding and glutathione (GSH) conjugate formation in rat and human liver microsomes were investigated using 10 representative radioactive compounds that have been reported as hepatotoxic or having other toxicity derived from their reactive intermediates: acetaminophen, amodiaquine, carbamazepine, clozapine, diclofenac, furosemide, imipramine, indomethacin, isoniazid, and tienilic acid, all at a concentration of 10 microM. The GSH conjugate formation rate correlates well with the covalent binding of radioactivity (both rat and human, r2 = 0.93), which suggests that quantification of the GSH conjugate can be used to estimate covalent binding. To quantify the GSH-conjugation rate with non-radiolabeled compounds in vitro, the validation study for the determination of GSH conjugate formation using 35S-GSH by radio-HPLC was useful to predict metabolic activation. Following oral administration of 20 mg/kg of the radiolabeled compounds to rats, radioactivity that covalently bound to plasma and liver proteins was determined. The in vivo maximum covalent binding level in liver based on the free fraction of plasma area under the concentration curve (AUC) and in vitro covalent binding rate was found to correlate well (r2 = 0.79). Therefore, this model for in vitro covalent binding studies in human and rat and in vivo rat studies might be useful in predicting human metabolic activation of compounds. PMID:17309281

  18. ANTIMICROBIAL ACTIVITY OF LACTIC ACID BACTERIAL ISOLATES

    Directory of Open Access Journals (Sweden)

    Utkarsha S. Shivsharan

    2013-08-01

    Full Text Available Micro-organisms have tendency to produce antimicrobial substances which show biological activity against other kind of micro-organisms. This phenomenon of bacterial antagonism is observed in lactic acid bacteria with competitive advantages. The lactic acid bacteria are commonly present in many fermented products, fruits and milk products. The variety of antimicrobial substances produced by lactic acid bacteria showing good inhibition capacity include production of lactic acid, acetic acid, hydrogen peroxide, carbon dioxide, diacetyl and bacteriocin. Bacteriocins produced by lactic acid bacteria are the subject of intense research because of their antimicrobial activity against food born bacteria such as Listeria monocytogenes, staphylococcus aureus, Bacillus cereus, Clostridium botulinum and several others .Bacteriocins may be bacteriostatic or bactericidal with narrow or broad range of activity. The main of the study was to study the antimicrobial activity of such lactic acid bacterial isolates.

  19. Reactive extraction of lactic acid using alamine 336 in MIBK: equilibria and kinetics.

    Science.gov (United States)

    Wasewar, Kailas L; Heesink, A Bert M; Versteeg, Geert F; Pangarkar, Vishwas G

    2002-07-17

    Lactic acid is an important commercial product and extracting it out of aqueous solution is a growing requirement in fermentation based industries and recovery from waste streams. The design of an amine extraction process requires (i) equilibrium and (ii) kinetic data for the acid-amine (solvent) system used. Equilibria for lactic acid extraction by alamine 336 in methyl-iso-butyl-ketone (MIBK) as a diluent have been determined. The extent to which the organic phase (amine +MIBK) may be loaded with lactic acid is expressed as a loading ratio, z=[HL](o)/[B](i,o). Calculations based on the stoichiometry of the reactive extraction and the equilibria involved indicated that more lactic acid is transferred to the organic phase than would be expected from the (1:1) stoichiometry of the reaction. The extraction equilibrium was interpreted as a result of consecutive formation of two acid-amine species with stoichiometries of 1:1 and 2:1. Equilibrium complexation constant for (1:1) and (2:1) has been estimated. Kinetics of extraction of lactic acid by alamine 336 in MIBK has also been determined. In a first study of its kind, the theory of extraction accompanied by a chemical reaction has been used to obtain the kinetics of extraction of lactic acid by alamine 336 in MIBK. The reaction between lactic acid and alamine 336 in MIBK in a stirred cell falls in Regime 3, extraction accompanied by a fast chemical reaction occurring in the diffusion film. The reaction has been found to be zero order in alamine 336 and first order in lactic acid with a rate constant of 1.38 s(-1). These data will be useful in the design of extraction processes. PMID:12052683

  20. Electron transport chains of lactic acid bacteria

    OpenAIRE

    Brooijmans, R.J.W.

    2008-01-01

    Lactic acid bacteria are generally considered facultative anaerobic obligate fermentative bacteria. They are unable to synthesize heme. Some lactic acid bacteria are unable to form menaquinone as well. Both these components are cofactors of respiratory (electron transport) chains of prokaryotic bacteria. Lactococcus lactis, and several other lactic acid bacteria, however respond to the addition of heme in aerobic growth conditions. This response includes increased biomass and robustness. In t...

  1. New trends and challenges in lactic acid production on renewable biomass

    Directory of Open Access Journals (Sweden)

    Đukić-Vuković Aleksandra J.

    2011-01-01

    Full Text Available Lactic acid is a relatively cheap chemical with a wide range of applications: as a preservative and acidifying agent in food and dairy industry, a monomer for biodegradable poly-lactide polymers (PLA in pharmaceutical industry, precursor and chemical feedstock for chemical, textile and leather industries. Traditional raw materials for fermentative production of lactic acid, refined sugars, are now being replaced with starch from corn, rice and other crops for industrial production, with a tendency for utilization of agro industrial wastes. Processes based on renewable waste sources have ecological (zero CO2 emission, eco-friendly by-products and economical (cheap raw materials, reduction of storage costs advantages. An intensive research interest has been recently devoted to develop and improve the lactic acid production on more complex industrial by-products, like thin stillage from bioethanol production, corncobs, paper waste, straw etc. Complex and variable chemical composition and purity of these raw materials and high nutritional requirements of Lare the main obstacles in these production processes. Media supplementation to improve the fermentation is an important factor, especially from an economic point of view. Today, a particular challenge is to increase the productivity of lactic acid production on complex renewable biomass. Several strategies are currently being explored for this purpose such as process integration, use of Lwith amylolytic activity, employment of mixed cultures of Land/or utilization of genetically engineered microorganisms. Modern techniques of genetic engineering enable construction of microorganisms with desired characteristics and implementation of single step processes without or with minimal pre-treatment. In addition, new bioreactor constructions (such as membrane bioreactors, utilization of immobilized systems are also being explored. Electrodialysis, bipolar membrane separation process, enhanced filtration

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

    Science.gov (United States)

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

    2016-07-01

    Consumers are increasingly becoming aware of their health and nutritional requirements, and in this context, vitamins produced in situ by microbes may suit their needs and expectations. B groups vitamins are essential components of cellular metabolism and among them riboflavin is one of the vital vitamins required by bacteria, plants, animals and humans. Here, we focus on the importance of microbial production of riboflavin over chemical synthesis. In addition, genetic abilities for riboflavin biosynthesis by lactic acid bacteria are discussed. Genetically modified strains by employing genetic engineering and chemical analogues have been developed to enhance riboflavin production. The present review attempts to collect the currently available information on riboflavin production by microbes in general, while placing greater emphasis on food grade lactic acid bacteria and human gut commensals. For designing riboflavin-enriched functional foods, proper selection and exploitation of riboflavin-producing lactic acid bacteria is essential. Moreover, eliminating the in situ vitamin fortification step will decrease the cost of food production. PMID:26686515

  3. Bioconversion of renewable resources into lactic acid: an industrial view.

    Science.gov (United States)

    Yadav, A K; Chaudhari, A B; Kothari, R M

    2011-03-01

    Lactic acid, an anaerobic product of glycolysis, can be theoretically produced by synthetic route; however, it is commercially produced by homo-fermentative batch mode of operations. Factors affecting its production and strategies improving it are considered while devising an optimized protocol. Although a hetero-fermentative mode of production exists, it is rarely used for commercial production. Attempts to use Rhizopus sp. for lactic acid production through either hetero-fermentative or thermophilic conditions were not economical. Since almost 70% of the cost of its production is accounted by raw materials, R & D efforts are still focused to find economically attractive agri-products to serve as sources of carbon and complex nitrogen inputs to meet fastidious nutrient needs for microbial growth and lactic acid production. Therefore, need exists for using multi-pronged strategies for higher productivity. Its present production and consumption scenario is examined. Its optically active isomers and chemical structure permit its use for the production of several industrially important chemicals, health products (probiotics), food preservatives, and bio-plastics. In addition, its salts and esters appear to have a variety of applications. PMID:20476870

  4. PARÁMETROS FISICOQUÍMICOS PARA LA SÍNTESIS DE ÁCIDO LÁCTICO O ETANOL DE LA BACTERIA (Corynebacterium glutamicum Physico-Chemical Parameter for Production of Lactic Acid or Ethanol of (Corynebacterium glutamicum Bacteria

    Directory of Open Access Journals (Sweden)

    ANGÉLICA CASTELLANOS

    2011-08-01

    Full Text Available El interés por obtener productos para la industria de biocombustibles a partir de desechos agrícolas, conduce a la búsqueda de nuevos sistemas biotecnológicos resistentes y costo-efectivos. Corynebacterium glutamicum, es un microorganismo usado para producir amino-ácidos que crece en gran variedad de sustratos y es resistente durante la fermentación, a variaciones de pH, temperatura, presión osmótica y acumulación de alcohol, características que lo hacen candidato a ser mejorado para la síntesis de ácido láctico y etanol. Aún se desconocen aspectos de su fisiología que aumenten su eficiencia en convertir azúcares (C5 y C6 en estos dos metabolitos. Por tanto, este trabajo buscó identificar los parámetros fisicoquímicos que tuvieron un mayor efecto sobre crecimiento bacteriano y síntesis de ácido láctico o etanol en un sistema por lotes. Para lograr este objetivo, ocho variables fueron evaluadas en un modelo estadístico producido en erlenmeyer; con los resultados obtenidos, se hallaron las mejores condiciones que fueron puestas a prueba en un cultivo en biorreactor. La temperatura, concentración de biotina y azúcar fueron las variables de mayor impacto (pThe interest to obtain products for the bio-fuel industry from renewable resources has directed research to find resistant and costs-effective biotechnological systems. Corynebacterium glutamicum, is a microorganism used to produce amino acids, that grows in wide variety of substrates and its resistance during fermentation to pH, temperature, osmotic pressure variations and alcohol aggregate, renders this organism a suitable candidate to improve by genetic modifications lactic acid and ethanol synthesis. However, some aspects of its physiology remain unknown, such us increase lactic acid and ethanol production from C5 and C6 sugars. For this reason, the main aim in our work was to identify the most important variables with impact on culture and the best culture conditions

  5. Formation of Lactic Acid from Cellulosic Biomass by Alkaline Hydrothermal Reaction

    Science.gov (United States)

    Yan, X.; Jini, F.; Kishita, A.; Enomoto, H.; Tohji, K.

    2008-02-01

    Glucose, as a model compound of cellulosic biomass, was used as a test material. Ca(OH)2 and NaOH were selected as alkali. Results showed that both NaOH and Ca(OH)2, can promote the formation of lactic acid in a hydrothermal reaction of glucose. In the case of the addition of NaOH, lactic acid was obtained with a good yield of 27% based on a carbon base at 300 °C for 60 s with a NaOH concentration of 2.5 M. In the case of the addition of Ca(OH)2, the highest yield of lactic acid is 20%, which occurred at 300 °C for 60 s with a Ca(OH)2 concentration of 0.32 M. The formation mechanisms of lactic acid from glucose were also discussed according to intermediate products identified. Lactic acid may be generated via formaldehyde, glycolaldehyde besides via the aldose having three carbon atoms in hydrothermal reaction which all formed by the reverse aldol condensation of hexoses.

  6. RECOVERY OF LACTIC ACID FROM AMERICAN CRYSTAL SUGAR COMPANY WASTEWATER

    Energy Technology Data Exchange (ETDEWEB)

    Daniel J. Stepan; Edwin S. Olson; Richard E. Shockey; Bradley G. Stevens; John R. Gallagher

    2001-04-30

    , self-supporting thin films and have, therefore, been used for adhesives, safety glass, and finishes. If the bacterial culture produces the L-lactic acid enanatiomer form exclusively, the L-lactide prepared from this form can be used for making polymers with good fiber-forming properties. We have not currently achieved the exclusive production of L-lactate in our efforts. However, markets in films and structural shapes are available for polymers and copolymers prepared from the mixed D,L-lactide forms that result from processing the D,L-lactic acid obtained from fermentation such as that occurring naturally in sugar beet wastewater. These materials are slowly biodegraded to harmless compounds in the environment, and they burn with a clean blue flame when incinerated. These materials represent excellent opportunities for utilization of the D,L-lactic mixture produced from natural fermentation of the ACS flume water. Esters can be converted into a lactide, and the alcohol released from the ester can be recycled with no net consumption of the alcohol. Lactide intermediates could be produced locally and shipped to polymer producers elsewhere. The polymer and copolymer markets are extremely large, and the role of lactides in these markets is continuously expanding. The overall process can be readily integrated into existing factory wastewater operations. There are several environmental benefits that would be realized at the factories with incorporation of the lactate recovery process. The process reduces the organic loading to the existing wastewater treatment system that should result in enhanced operability with respect to both solids handling and treated-water quality. A higher-quality treated water will also help reduce odor levels from holding ponds. Several water reuse opportunities are probable, depending on the quality of treated water from the FT process.

  7. Effect of carbonyl inhibitors and their H₂O₂ detoxification on lactic acid fermentation.

    Science.gov (United States)

    Li, Jing; Zhu, Caiqing; Tu, Maobing; Han, Pingping; Wu, Yonnie

    2015-04-01

    Biomass degradation compounds significantly inhibit biochemical conversion of biomass prehydrolysates to biofuels and chemicals, such as lactic acid. To characterize the structure-activity relationship of carbonyl inhibition on lactic acid fermentation, we examined effects of eight carbonyl compounds (furfural, 5-hydroxymethyl furfural, vanillin, syringaldehyde, 4-hydroxybenzaldehyde, phthalaldehyde, benzoic acid, and pyrogallol aldehyde) and creosol on lactic acid production by Lactobacillus delbrueckii. Pyrogallol aldehyde reduced the cell growth rate by 35 % at 1.0 mM and inhibited lactic acid production completely at 2.0 mM. By correlating the molecular descriptors to the inhibition constants in lactic acid fermentation, we found a good relationship between the hydrophobicity (Log P) of aldehydes and their inhibition constants in fermentation. The inhibitory effect of carbonyl inhibitors appeared to correlate with their thiol reactivity as well. In addition, we found that H2O2 detoxified pyrogallol aldehyde and phthalaldehyde inhibitory activity. H2O2 detoxification was applied to real biomass prehydrolysates in lactic acid fermentation. PMID:25666370

  8. Lactic acid production from cellobiose and xylose by engineered Saccharomyces cerevisiae.

    Science.gov (United States)

    Turner, Timothy L; Zhang, Guo-Chang; Oh, Eun Joong; Subramaniam, Vijay; Adiputra, Andrew; Subramaniam, Vimal; Skory, Christopher D; Jang, Ji Yeon; Yu, Byung Jo; Park, In; Jin, Yong-Su

    2016-05-01

    Efficient and rapid production of value-added chemicals from lignocellulosic biomass is an important step toward a sustainable society. Lactic acid, used for synthesizing the bioplastic polylactide, has been produced by microbial fermentation using primarily glucose. Lignocellulosic hydrolysates contain high concentrations of cellobiose and xylose. Here, we constructed a recombinant Saccharomyces cerevisiae strain capable of fermenting cellobiose and xylose into lactic acid. Specifically, genes (cdt-1, gh1-1, XYL1, XYL2, XYL3, and ldhA) coding for cellobiose transporter, β-glucosidase, xylose reductase, xylitol dehydrogenase, xylulokinase, and lactate dehydrogenase were integrated into the S. cerevisiae chromosomes. The resulting strain produced lactic acid from cellobiose or xylose with high yields. When fermenting a cellulosic sugar mixture containing 10 g/L glucose, 40 g/L xylose, and 80 g/L cellobiose, the engineered strain produced 83 g/L of lactic acid with a yield of 0.66 g lactic acid/g sugar (66% theoretical maximum). This study demonstrates initial steps toward the feasibility of sustainable production of lactic acid from lignocellulosic sugars by engineered yeast. PMID:26524688

  9. Lactic Acid Bacteria in the Gut

    NARCIS (Netherlands)

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

    2012-01-01

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

  10. Comparative genomics of the lactic acid bacteria

    Science.gov (United States)

    Lactic acid-producing bacteria are associated with various plant and animal niches and play a key role in the production of fermented foods and beverages. We report nine genome sequences representing the phylogenetic and functional diversity of these bacteria. The small genomes of lactic acid bacter...

  11. PHAGE RESISTANT LACTIC ACID BACTERIAL MUTANTS

    DEFF Research Database (Denmark)

    2001-01-01

    Method of obtaining mutated lactic acid bacteria having a reduced susceptibility towards attack by bacteriophages, the method comprising mutating a gene involved in the pyrimidine metabolism, including pyrG encoding CTP synthetase. Such lactic acid bacteria are useful in starter cultures in the...

  12. Hetropolyacid-Catalyzed Oxidation of Glycerol into Lactic Acid under Mild Base-Free Conditions.

    Science.gov (United States)

    Tao, Meilin; Yi, Xiaohu; Delidovich, Irina; Palkovits, Regina; Shi, Junyou; Wang, Xiaohong

    2015-12-21

    Lactic acid (LA) is a versatile platform molecule owing to the opportunity to transform this compound into useful chemicals and materials. Therefore, efficient production of LA based on inexpensive renewable feedstocks is of utmost importance for insuring its market availability. Herein, we report the efficient conversion of glycerol into LA catalyzed by heteropolyacids (HPAs) under mild base-free conditions. The catalytic performance of molecular HPAs appears to correlate with their redox potential and Brønsted acidity. Namely, H3 PMo(12)O(40) (HPMo) exhibits the best selectivity towards LA (90 %) with 88 % conversion of glycerol. Loading of HPMo onto a carbon support (HPMo/C) further improves LA productivity resulting in 94 % selectivity at 98 % conversion under optimized reaction conditions. The reaction takes place through the formation of dihydroxyacetone/glyceraldehyde and pyruvaldehyde as intermediates. No leaching of HPMo was observed under the applied reaction conditions and HPMo/C could be recycled 5 times without significant loss of activity. PMID:26611678

  13. Utilization of supplemented sugarcane molasses for continuous production of lactic acid by Lactobacillus curvatus/
    Produção contínua de ácido láctico por Lactobacillus curvatus a partir de melaço de cana-de-açúcar suplementado

    OpenAIRE

    Maria Célia de Oliveira Hauly; João Batista Buzato; Andréa Rocha de Oliveira

    2005-01-01

    Several by-products and raw-materials of food and agricultural industries have been used as culture medium. It is rich nutrients sources, and it is considered low cost and high availability of molasses as a substrate can be used in lactic fermentation. Lactic acid has tradicionally been obtained by chemical process, however, lactic acid production by fermentative process is considered most viable economically. Lactic acid has application in different industries such as pharmaceutical, cosmeti...

  14. Protein-chemical characterization of NF-H, the largest mammalian neurofilament component; intermediate filament-type sequences followed by a unique carboxy-terminal extension

    OpenAIRE

    Geisler, N; Fischer, S.; Vandekerckhove, J; Van Damme, J; Plessmann, U.; Weber, K.

    1985-01-01

    NF-H has the highest mol. wt. of the three mammalian neurofilament components (NF-L, NF-M, NF-H). In spite of its unusually large mol. wt., estimated to be 200 K by gel electrophoresis, NF-H contains sequences which identify it as an integral intermediate filament (IF) protein in its amino-terminal region. We have isolated and partially characterized a basic, non-α-helical segment located at the amino-terminal end with properties similar to headpieces of other non-epithelial IF proteins. The ...

  15. Selection of lactic acid bacteria able to ferment inulin hydrolysates

    OpenAIRE

    Octavian BASTON; Oana Emilia CONSTANTIN

    2012-01-01

    Eight homofermentative lactic acid bacteria isolates were tested for lactic acid production using chicory and Jerusalem artichoke hydrolysate as substrate. The pH, lactic acid yield and productivity were used to select the best homolactic bacteria for lactic acid production. The selected strains produced lactic acid at maximum yield after 24 hours of fermentation and the productivity was greater at 24 hours of fermentation. From all studied strains, Lb1 and Lb2 showed the best results regardi...

  16. Genetics of Lactic Acid Bacteria

    Science.gov (United States)

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

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

  17. Solution blow spun Poly(lactic acid)/Hydroxypropyl methylcellulose nanofibers with antimicrobial properties

    Science.gov (United States)

    Poly(lactic acid) (PLA) nanofibers containing hydroxypropyl methylcellulose (HPMC) and tetracycline hydrochloride (THC) were solution blow spun from two different solvents, chloroform/acetone (CA, 80:20 v/v) and 2,2,2-triflouroethanol (TFE). The diameter distribution, chemical, thermal, thermal stab...

  18. Understanding lactic acidosis in paracetamol (acetaminophen) poisoning

    OpenAIRE

    Shah, Anoop D; Wood, David M; Dargan, Paul I

    2011-01-01

    Paracetamol (acetaminophen) is one of the most commonly taken drugs in overdose in many areas of the world, and the most common cause of acute liver failure in both the UK and USA. Paracetamol poisoning can result in lactic acidosis in two different scenarios. First, early in the course of poisoning and before the onset of hepatotoxicity in patients with massive ingestion; a lactic acidosis is usually associated with coma. Experimental evidence from studies in whole animals, perfused liver sl...

  19. Characteristics and Role of Mesophilic Lactic Cultures

    OpenAIRE

    Dubravka Samaržija; Jasmina Lukač Havranek; Neven Antunac; Sanja Sikora

    2001-01-01

    The use of lactococci is widespread and has the longest tradition in industrial mesophilic lactic cultures technology. The principal concern of the dairy industry is the reliability and stability of these cultures. This paper describes the major technologically important properties of mesophilic lactic cultures when they are used for fermentation of milk and the production of cheese. This paper includes some of the specific properties of lactococci strains which can help in making the right c...

  20. Quorum sensing mechanism in lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Hatice Yılmaz - Yıldıran

    2015-04-01

    and detection occurs as a consecution it is hard to understand their QS mechanism. In this review, connection between QS mechanism and some characteristics of lactic acid bacteria are evaluated such as concordance with its host, inhibition of pathogen development and colonization in gastrointestinal system, bacteriocin production, acid and bile resistance, adhesion to epithelium cells. Understanding QS mechanism of lactic acid bacteria will be useful to design metabiotics which is defined as novel probiotics.

  1. CHEMICALS

    CERN Multimedia

    Medical Service

    2002-01-01

    It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546

  2. A perspective on Serum Lactic acid, Lactic Acidosis in a Critical Care Unit

    Directory of Open Access Journals (Sweden)

    Agela A.Elbadri

    2013-06-01

    Full Text Available Breast cancer is one of the major surgical problems encountered in Libya. Lactic acidosis is a universal complication in breast cancer patients and can be considered a possible prognostic marker. Therefore, it will be beneficial to correctly understand and review the biochemistry underlying lactic acidosis and its possible significance as a prognostic marker in critical care patients, including breast cancer.

  3. A solid form of ambazone with lactic acid

    Science.gov (United States)

    Borodi, Gh.; Muresan-Pop, M.; Kacsó, I.; Bratu, I.

    2012-02-01

    In recent years, much research has been carried out on the preparation of pharmaceutical solid forms due to their improved physical-chemical parameters such as solubility, dissolution rate of the drug, chemical stability, melting point and hygroscopic parameter. The aim of this study was to obtain and to investigate the structural properties of the ambazone (AMB) with lactic acid (LA) solid form. The solid form was obtained starting from the mixture of ambazone with lactic acid (1:1), by grinding method at constant temperature. The obtained compound was investigated via X-ray powder diffraction (PXRD), thermal analysis (DSC, TG-DTA) and infrared (FTIR) spectroscopy. The difference between the patterns of AMB•LA and of the starting compounds evidenced a new compound. Using X-ray powder diffraction method, by indexing procedure the unit cell and the lattice parameters were determined. Thermal and FTIR measurements on the pure compounds and on the (1:1) ground mixture of AMB with LA confirm the new salt form formation.

  4. Stabilization of the Simplest Criegee Intermediate from the Reaction between Ozone and Ethylene: A High-Level Quantum Chemical and Kinetic Analysis of Ozonolysis.

    Science.gov (United States)

    Nguyen, Thanh Lam; Lee, Hyunwoo; Matthews, Devin A; McCarthy, Michael C; Stanton, John F

    2015-06-01

    The fraction of the collisionally stabilized Criegee species CH2OO produced from the ozonolysis of ethylene is calculated using a two-dimensional (E, J)-grained master equation technique and semiclassical transition-state theory based on the potential energy surface obtained from high-accuracy quantum chemical calculations. Our calculated yield of 42 ± 6% for the stabilized CH2OO agrees well, within experimental error, with available (indirect) experimental results. Inclusion of angular momentum in the master equation is found to play an essential role in bringing the theoretical results into agreement with the experiment. Additionally, yields of HO and HO2 radical products are predicted to be 13 ± 6% and 17 ± 6%, respectively. In the kinetic simulation, the HO radical product is produced mostly from the stepwise decomposition mechanism of primary ozonide rather than from dissociation of hot CH2OO. PMID:25945650

  5. Lactic Acidosis: Current Treatments and Future Directions.

    Science.gov (United States)

    Kraut, Jeffrey A; Madias, Nicolaos E

    2016-09-01

    Mortality rates associated with severe lactic acidosis (blood pHreduce mortality. This failure has been attributed to both reduction in serum calcium concentration and generation of excess carbon dioxide with intracellular acidification. In animal studies, hyperventilation and infusion of calcium during sodium bicarbonate administration improves cardiovascular function, suggesting that this approach could allow expression of the positive aspects of sodium bicarbonate. Other buffers, such as THAM or Carbicarb, or dialysis might also provide base with fewer untoward effects. Examination of these therapies in humans is warranted. The cellular injury associated with lactic acidosis is partly due to activation of NHE1, a cell-membrane Na(+)/H(+) exchanger. In animal studies, selective NHE1 inhibitors improve cardiovascular function, ameliorate lactic acidosis, and reduce mortality, supporting future research into their possible use in humans. Two main mechanisms contribute to lactic acid accumulation in sepsis and low-flow states: tissue hypoxia and epinephrine-induced stimulation of aerobic glycolysis. Targeting these mechanisms could allow for more specific therapy. This Acid-Base and Electrolyte Teaching Case presents a patient with acute lactic acidosis and describes current and future approaches to treatment. PMID:27291485

  6. Intermediate-scale 2D experimental investigation of in situ chemical oxidation using potassium permanganate for remediation of complex DNAPL source zones

    Science.gov (United States)

    Heiderscheidt, J. L.; Siegrist, R. L.; Illangasekare, T. H.

    2008-11-01

    In situ chemical oxidation is a technology that has been applied to speed up remediation of a contaminant source zone by inducing increased mass transfer from DNAPL sources into the aqueous phase for subsequent destruction. The DNAPL source zone can consist of one or more individual sources that may be present as an interconnected pool of high saturation, as a region of disconnected ganglia at residual saturation, or as combinations of these two morphologies. Potassium permanganate (KMnO 4) is a commonly employed oxidant that has been shown to rapidly destroy DNAPL compounds like PCE and TCE following second-order kinetics in an aqueous system. During the oxidation of a target DNAPL compound, or naturally occurring reduced species in the subsurface, manganese oxide (MnO 2) solids are produced. Research has shown that these manganese oxide solids may result in permeability reductions in the porous media thus reducing the ability for oxidant to be transported to individual DNAPL sources. It can also occur at the DNAPL-water interface, decreasing contact of the oxidant with the DNAPL. Additionally, MnO 2 formation at the DNAPL-water interface, and/or flow-bypassing as a result of permeability reductions around the source, may alter the mass transfer from the DNAPL into the aqueous phase, potentially diminishing the magnitude of any DNAPL mass depletion rate increase induced by oxidation. An experiment was performed in a two-dimensional (2D) sand-filled tank that included several discrete DNAPL source zones. Spatial and temporal monitoring of aqueous PCE, chloride, and permanganate concentrations was used to relate changes in mass depletion of, and mass flux, from DNAPL residual and pool source zones to chemical oxidation performance and MnO 2 formation. During the experiment, permeability changes were monitored throughout the 2D tank and these were related to MnO 2 deposition as measured through post-oxidation soil coring. Under the conditions of this experiment, Mn

  7. EFFECT OF NITROGEN SOURCE AND INITIAL SUGAR CONCENTRATION ON LACTIC ACID FERMENTATION OF PINEAPPLE WASTE USING L.DELBRUECKII

    Directory of Open Access Journals (Sweden)

    Abdullah Moch Busairi

    2012-02-01

    Full Text Available The liquid pineapple waste contains mainly sucrose, glucose, fructose and other nutrients. It therefore can potentially be used as carbon source for lactic acid fermentation. The lactic acid is utilised in food technology as pH regulator, microbial preservative, buffering agent and in the chemical industry. Recently, lactic acid has been considered to be an important raw material for production of biodegradable lactate polymer. The experiments were carried out in batch fermentation at anaerobic condition with stirring speed: 50 rpm, temperature: 40 oC, pH: 6.0, and inoculum size: 5%. Effect of nitrogen source and initial sugar concentration were studied. The effect of nitrogen source on lactic acid production shows that the yeast extract is highest yield , followed by urea , corn steep liquor, malt sprout and ammonium sulphates with the yield of 78.52; 26.68; 19.14; 14.10 and 5.6 %, respectively. The highest yield of initial sugar concentration on lactic acid production obtained was 78.52 % (54.97 g/l at 70 g/l, if the concentration of sugar was increased to 110 g/l , the lactic acid production or yield decrease to51.53 g/l or 54.24%.

  8. Novel Method of Lactic Acid Production by Electrodialysis Fermentation

    OpenAIRE

    Hongo, Motoyoshi; Nomura, Yoshiyuki; Iwahara, Masayoshi

    1986-01-01

    In lactic acid fermentation by Lactobacillus delbrueckii, the produced lactic acid affected the lactic acid productivity. Therefore, for the purpose of alleviating this inhibitory effect, an electrodialysis fermentation method which can continuously remove produced lactic acid from the fermentation broth was applied to this fermentation process. As a result, the continuation of fermentation activity was obtained, and the productivity was three times higher than in non-pH-controlled fermentati...

  9. Comparative genomics of the lactic acid bacteria

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-06-01

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

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

    NARCIS (Netherlands)

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

    1998-01-01

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

  11. A method for the determination of D(-)-lactic acid

    NARCIS (Netherlands)

    Hamer, C.J.A. van den; Elias, R.W.

    1958-01-01

    A method for the determination of D(—)-lactic acid is described. An acetone powder from Escherichia coli B in the presence of methylene blue oxidizes D(—)-lactic specifically. Oxygen consumption in a Warburg apparatus was used as a measure of the D(—)-lactic acid.

  12. Naturally occurring lactic Acid bacteria isolated from tomato pomace silage.

    Science.gov (United States)

    Wu, Jing-Jing; Du, Rui-Ping; Gao, Min; Sui, Yao-Qiang; Xiu, Lei; Wang, Xiao

    2014-05-01

    Silage making has become a significant method of forage conservation worldwide. To determine how tomato pomace (TP) may be used effectively as animal feed, it was ensilaged for 90 days and microbiology counts, fermentation characteristics and chemical composition of tomato pomace silage (TPS) were evaluated at the 30th, 60th, and 90th days, respectively. In addition, 103 lactic acid bacteria were isolated from TPS. Based on the phenotypic and chemotaxonomic characteristics, 16S rDNA sequence and carbohydrate fermentation tests, the isolates were identified as 17 species namely: Lactobacillus coryniformis subsp. torquens (0.97%), Lactobacillus pontis (0.97%), Lactobacillus hilgardii (0.97%), Lactobacillus pantheris (0.97%), Lactobacillus amylovorus (1.9%), Lactobacillus panis (1.9%), Lactobacillus vaginalis (1.9%), Lactobacillus rapi (1.9%), Lactobacillus buchneri (2.9%), Lactobacillus parafarraginis (2.9%), Lactobacillus helveticus (3.9%), Lactobacillus camelliae (3.9%), Lactobacillus fermentum (5.8%), Lactobacillus manihotivorans (6.8%), Lactobacillus plantarum (10.7%), Lactobacillus harbinensis (16.5%) and Lactobacillus paracasei subsp. paracasei (35.0%). This study has shown that TP can be well preserved for 90 days by ensilaging and that TPS is not only rich in essential nutrients, but that physiological and biochemical properties of the isolates could provide a platform for future design of lactic acid bacteria (LAB) inoculants aimed at improving the fermentation quality of silage. PMID:25049999

  13. Naturally Occurring Lactic Acid Bacteria Isolated from Tomato Pomace Silage

    Science.gov (United States)

    Wu, Jing-jing; Du, Rui-ping; Gao, Min; Sui, Yao-qiang; Xiu, Lei; Wang, Xiao

    2014-01-01

    Silage making has become a significant method of forage conservation worldwide. To determine how tomato pomace (TP) may be used effectively as animal feed, it was ensilaged for 90 days and microbiology counts, fermentation characteristics and chemical composition of tomato pomace silage (TPS) were evaluated at the 30th, 60th, and 90th days, respectively. In addition, 103 lactic acid bacteria were isolated from TPS. Based on the phenotypic and chemotaxonomic characteristics, 16S rDNA sequence and carbohydrate fermentation tests, the isolates were identified as 17 species namely: Lactobacillus coryniformis subsp. torquens (0.97%), Lactobacillus pontis (0.97%), Lactobacillus hilgardii (0.97%), Lactobacillus pantheris (0.97%), Lactobacillus amylovorus (1.9%), Lactobacillus panis (1.9%), Lactobacillus vaginalis (1.9%), Lactobacillus rapi (1.9%), Lactobacillus buchneri (2.9%), Lactobacillus parafarraginis (2.9%), Lactobacillus helveticus (3.9%), Lactobacillus camelliae (3.9%), Lactobacillus fermentum (5.8%), Lactobacillus manihotivorans (6.8%), Lactobacillus plantarum (10.7%), Lactobacillus harbinensis (16.5%) and Lactobacillus paracasei subsp. paracasei (35.0%). This study has shown that TP can be well preserved for 90 days by ensilaging and that TPS is not only rich in essential nutrients, but that physiological and biochemical properties of the isolates could provide a platform for future design of lactic acid bacteria (LAB) inoculants aimed at improving the fermentation quality of silage. PMID:25049999

  14. Zeolite H-USY for the production of lactic acid and methyl lactate from C-3-sugars

    DEFF Research Database (Denmark)

    West, R.M.; Holm, Martin Spangsberg; Shunmugavel, Saravanamurugan;

    2010-01-01

    Lactic acid is an interesting platform chemical with many promising applications. This includes the use as a building block for the production of biodegradable plastics and environmentally friendly solvents. A study of the liquid-phase conversion of the triose-sugars, glyceraldehyde and dihydroxy......Lactic acid is an interesting platform chemical with many promising applications. This includes the use as a building block for the production of biodegradable plastics and environmentally friendly solvents. A study of the liquid-phase conversion of the triose-sugars, glyceraldehyde and...... the catalytic activity to data obtained by TPO, XRD, N-2-sorption, and NH3-TPD on fresh and used catalysts. Coking and irreversible framework damage occurs when lactic acid is produced under aqueous conditions. In methanol, methyl lactate is produced and catalyst deactivation is suppressed...

  15. Screening of microorganisms for biodegradation of poly(lactic-acid) and lactic acid-containing polymers.

    OpenAIRE

    Torres, A.; Li, S.M.; S. Roussos; Vert, M.

    1996-01-01

    The ability of some microorganisms to use lactic acid stereocopolymers and copolymers with glycolic acid as sole carbon and energy sources was studied under controlled or natural conditions. First, 14 filamentous fungal strains were tested in liquid cultures, adopting total lactic acid consumption, nitrogen source exhaustion, and maximal biomass production as selection criteria. Two strains of #Fusarium moniliforme$ and one strain of #Penicillium roqueforti$ were able to totally assimilate DL...

  16. Genetics of proteinases of lactic acid bacteria

    NARCIS (Netherlands)

    Kok, Jan; Venema, Gerhardus

    1988-01-01

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

  17. LACTIC FLORA-LISTERIA MONOCYTOGENES INTERACTION

    Directory of Open Access Journals (Sweden)

    S. Colombo

    2012-08-01

    Full Text Available The EC Regulation 2073/2005 (1 requires that food processors evaluate the capability of ready-to-use (RTE products to support the development of Listeria monocytogenes when their pH and aW values are favourable to the growth of this microorganism. It is renown that the lactic flora plays an important role in many different foods, both from a technological and a food safety standpoint. This study was aimed to observe the behaviour and the potential anti-Listeria effect of some natural lactic flora present in Italian liver patè crostini (chicken heart and liver, anchovies, onions, capers, starch, no added preservatives through the Combase Predictor – Max Growth Rate predictive software. The natural lactic flora of the crostini demonstrated a variable capability to inhibit the growth of Listeria monocytogenes which depends upon : the concentration of the lactic flora at the beginning of the shelf life period and the subsequent lag phase, the possible release of anti-Listeria substances, and the maximum growth rate.

  18. Discovering lactic acid bacteria by genomics

    NARCIS (Netherlands)

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

    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 ferment

  19. STUDY OF THE EFFECTS SHOWN BY THE ACTION OF VARIOUS MICROORGANISMS ON THE LACTIC FERMENTATION OF JUICES

    Directory of Open Access Journals (Sweden)

    Iuliana Manea

    2010-01-01

    Full Text Available Research has established the most effective lactic acid bacteria used for fermentation of fruit and vegetables juices. The cultures were used for Bifidobacteria, Lactobacillus acidophilus and culture of micro flora obtained spontaneous shoots. Lactic fermented juice was obtained from cabbage, carrots and beetroot. Working in these variants were determined lactic fermentation parameters and some of the bioactive compounds from this process: pH, reducing sugars, viable cell counts. Determination of reducing sugars calculated as glucose was conducted using the 3.5 dinitrosalicilic acid method (DNS method, pH was determined with a pH meter electronics. Chemical parameters listed were determined every two hours during the first 24 hours, then 48 and 72 hours in thermostatic conditions at 37 degrees C and 7 days storage at refrigerator temperature. At the end of the lactic fermentation, the lowest pH 4.31, which also provide juice conservation was obtained using a pure culture of Lactobacillus acidophilus. Reducing sugar is metabolized significantly when the juice of beetroot, fermented with Lactobacillus acidophilus culture, 75.19%. The results may be an argument for obtaining juice fermented lactic acid, which are popular functional foods, to obtain a chemical composition and sensory their optimum.

  20. Corrosion Behavior of Titanium in Artificial Saliva by Lactic Acid

    Directory of Open Access Journals (Sweden)

    Qing Qu

    2014-07-01

    Full Text Available As one of the main products produced by oral microorganisms, the role of lactic acid in the corrosion of titanium is very important. In this study, the corrosion behavior of titanium in artificial saliva with and without lactic acid were investigated by open-circuit potentials (OCPs, polarization curves and electrochemical impedance spectroscopy (EIS. OCP firstly increased with the amount of lactic acid from 0 to 3.2 g/L and then tended to decrease from 3.2 to 5.0 g/L. The corrosion of titanium was distinctly affected by lactic acid, and the corrosion rate increased with increasing the amount of lactic acid. At each concentration of lactic acid, the corrosion rate clearly increased with increasing the immersing time. Results of scanning electron microscopy (SEM also indicated that lactic acid accelerated the pitting corrosion in artificial saliva. A probable mechanism was also proposed to explain the experimental results.

  1. Fabrication and characterization of novel multilayered structures by stereocomplexion of poly(D-lactic acid)/poly(L-lactic acid) and self-assembly of polyelectrolytes.

    Science.gov (United States)

    Dellacasa, Elena; Zhao, Li; Yang, Gesheng; Pastorino, Laura; Sukhorukov, Gleb B

    2016-01-01

    The enantiomers poly(D-lactic acid) (PDLA) and poly(L-lactic acid) (PLLA) were alternately adsorbed directly on calcium carbonate (CaCO3) templates and on poly(styrene sulfonate) (PSS) and poly(allylamine hydrochloride) (PAH) multilayer precursors in order to fabricate a novel layer-by-layer (LBL) assembly. A single layer of poly(L-lysine) (PLL) was used as a linker between the (PDLA/PLLA) n stereocomplex and the cores with and without the polymeric (PSS/PAH) n /PLL multilayer precursor (PEM). Nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC) were used to characterize the chemical composition and molecular weight of poly(lactic acid) polymers. Both multilayer structures, with and without polymeric precursor, were firstly fabricated and characterized on planar supports. A quartz crystal microbalance (QCM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and ellipsometry were used to evaluate the thickness and mass of the multilayers. Then, hollow, spherical microcapsules were obtained by the removal of the CaCO3 sacrificial template. The chemical composition of the obtained microcapsules was confirmed by differential scanning calorimetry (DSC) and wide X-ray diffraction (WXRD) analyses. The microcapsule morphology was evaluated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) measurements. The experimental results confirm the successful fabrication of this innovative system, and its full biocompatibility makes it worthy of further characterization as a promising drug carrier for sustained release. PMID:26925356

  2. Study of mixed Ca-Zn hydroxyapatite surface modified by lactic acid

    International Nuclear Information System (INIS)

    The new hybrid inorganic-organic composites, Ca(10-x)Znx(PO4)6(OH)2-lactic acid, at different amounts of zinc and lactic acid were prepared by dissolution of the organic compound in an hydroxyapatite suspension. They were characterized by XRD, IR, MAS NMR (13C and 1H) and chemical analysis. The crystallinity was slightly affected by the presence of organic fragments. IR and (13C and 1H) MAS NMR measurements indicate that the carboxylic groups of the acid interact with calcium and zinc ions of hydroxyapatite surface. Chemical analysis displays that zinc promotes the acid grafting. A mechanism of surface modification is proposed based on the obtained results.

  3. Lactic acid fermentation of food waste for swine feed.

    Science.gov (United States)

    Yang, S Y; Ji, K S; Baik, Y H; Kwak, W S; McCaskey, T A

    2006-10-01

    This study was conducted to determine the effects of lactic acid bacteria (LAB, Lactobacillus salivarius) inoculation on the microbial, physical and chemical properties of food waste mixture (FWM) stored at ambient temperature (25 degrees C) for 10 and 30 days. A complete pig diet including restaurant food waste, bakery by-product, barley and wheat bran, and broiler poultry litter was amended with LAB at the levels of 0.1%, 0.2%, 0.5% and 1.0% and fermented anaerobically. These treatments were compared with intact FWM before storage and non-anaerobically stored FWM. Non-anaerobic storage of FWM showed microbial putrefaction with the loss (P 0.05) when LAB-added levels were over 0.2%. Based on these observations the optimum level of LAB addition to FWM was 0.2%. PMID:16257200

  4. Bacteriocins from lactic acid bacteria: purification, properties and use as biopreservatives

    OpenAIRE

    José Luis Parada; Carolina Ricoy Caron; Adriane Bianchi P. Medeiros; Carlos Ricardo Soccol

    2007-01-01

    Biopreservation systems in foods are of increasing interest for industry and consumers. Bacteriocinogenic lactic acid bacteria and/or their isolated bacteriocins are considered safe additives (GRAS), useful to control the frequent development of pathogens and spoiling microorganisms in foods and feed. The spreading of bacterial antibiotic resistance and the demand for products with fewer chemicals create the necessity of exploring new alternatives, in order to reduce the abusive use of therap...

  5. Selected Lactic Acid Bacteria Synthesize Antioxidant Peptides during Sourdough Fermentation of Cereal Flours

    OpenAIRE

    Coda, Rossana; Rizzello, Carlo Giuseppe; Pinto, Daniela; Gobbetti, Marco

    2012-01-01

    A pool of selected lactic acid bacteria was used for the sourdough fermentation of various cereal flours with the aim of synthesizing antioxidant peptides. The radical-scavenging activity of water/salt-soluble extracts (WSE) from sourdoughs was significantly (P < 0.05) higher than that of chemically acidified doughs. The highest activity was found for whole wheat, spelt, rye, and kamut sourdoughs. Almost the same results were found for the inhibition of linoleic acid autoxidation. WSE were su...

  6. Synthesis and Characterization of a Novel Biomaterial:Maleic Anhydride-modified Poly(dl-lactic acid)

    Institute of Scientific and Technical Information of China (English)

    Yan Feng LUO; Yuan Liang WANG; Xu Feng NIU; Jun PAN; Liang Ping SHI

    2004-01-01

    A novel modified poly(dl-lactic acid) (PDLLA) was obtained by covalently grafting of maleic anhydride onto the backbone of PDLLA, attempting to improve PDLLA's hydrophilicity and cell affinity and to provide reactive groups for further chemical modification. FTIR, 13C NMR and DSC were used to characterize the maleic anhydride-modified PDLLA.

  7. Properties of electrospun pollock gelatin/poly(vinyl alcohol) and pollock gelatin/poly(lactic acid) fibers

    Science.gov (United States)

    Pollock gelatin/poly(vinyl alcohol) (PVA) fibers were electrospun using deionized water as the solvent and pollock gelatin/poly(lactic acid) (PLA) fibers were electrospun using 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) as the solvent. The chemical, thermal, and thermal stability properties were exami...

  8. ISOLATION OF LACTIC ACID BACTERIA UNDER LOW TEMPERATURE FOR THE PREPARATION OF YOGURT

    Directory of Open Access Journals (Sweden)

    Javid Ahmad Bhat

    2014-02-01

    Full Text Available An investigation of isolation of Lactic acid bacteria was carried out under low temperature for the preparation of Yogurt by using various food supplements like carrot, ground-nut and tomato juices. Methods: Various samples of Cow milk, Skimmed milk were processed along with nutrients like Carrot, ground nut and tomato juices with Tryptone glucose yeast extract agar (TGYA at different temperatures like 50C, 150C and 220C for the isolation of Lactic acid bacteria for the preparation of yogurt. The characteristic isolates were identified by using various biochemical tests and direct microscopy. Results: Lactic acid bacteria (LAB dominated the microbial population of Yogurt, and were identified according to their morphological and physiological characteristics. Among these lactobacilli were frequently occurring organisms. The most abundant species were Lactobacillus delbrueckii subspecies Bulgaricus and Streptococcus thermophilus. The Lactic Streptococci was subjected to bio-chemical tests to identify the species. Based on the biochemical reactions the species was identified as Lactococcus Lactis, sub species di-acetylactis. Isolated culture of lactic Streptococci was found to grow at low temperature. When this was used as an inoculum to prepare yogurt at 50C, 150C and 220C curdling took place in 3days time. In order to reduce the setting time, nutrients in the form of carrot, ground-nut and tomato juices were added. The yogurt was found to set at 50C in 30hrs which is considered useful. Acidity of yogurt was found to be 0.53%- 0.55%. The yogurt was found to contain di-acetyl and quality of yogurt was good.

  9. Characteristics and Role of Mesophilic Lactic Cultures

    Directory of Open Access Journals (Sweden)

    Dubravka Samaržija

    2001-06-01

    Full Text Available The use of lactococci is widespread and has the longest tradition in industrial mesophilic lactic cultures technology. The principal concern of the dairy industry is the reliability and stability of these cultures. This paper describes the major technologically important properties of mesophilic lactic cultures when they are used for fermentation of milk and the production of cheese. This paper includes some of the specific properties of lactococci strains which can help in making the right choice of strains, depending on the product being produced. For example, most dairy fermentation require rapid acid production, ability to produce desired changes in milk and lack of off-flavour production. Certain strains of lactococci have the ability to produce exopolysaccharides or bacteriocines thus contributing to sensory properties of dairy products. In addition, these bacteria make important contribution

  10. Potential of Lactic Streptococci to Produce Bacteriocin

    OpenAIRE

    Geis, Arnold; Singh, Jasjit; Teuber, Michael

    1983-01-01

    A survey was made on the bacteriocin-producing potential of lactic streptococci. Bacteriocin-like activities were isolated and partially purified from about 5% of the 280 strains investigated. The frequency of production varied from about 1% in Streptococcus lactis subsp. diacetylactis to 9 and 7.5% in S. lactis and Streptococcus cremoris, respectively. Eight strains of S. cremoris produced bacteriocins which, on the basis of heat stability at different pH values and inhibitory spectrum, coul...

  11. Deoxyribonucleic Acid Homology Among Lactic Streptococci

    OpenAIRE

    Jarvis, Audrey W.; Jarvis, Brion D. W.

    1981-01-01

    A comparison was made by deoxyribonucleic acid homology of 45 strains of lactic streptococci, using two strains of Streptococcus cremoris and three strains of Streptococcus lactis as reference strains. All S. cremoris strains were grouped together by deoxyribonucleic acid homology. S. lactis strains formed a second group, except that three strains of S. lactis showed a high degree of homology with S. cremoris strains. The three Streptococcus diacetylactis strains could not be differentiated f...

  12. Efficient production of l-lactic acid using co-feeding strategy based on cane molasses/glucose carbon sources.

    Science.gov (United States)

    Xu, Ke; Xu, Ping

    2014-02-01

    L-Lactic acid is an important platform chemical, which ought to be produced under cost control to meet its huge demand. Cane molasses, a waste from sugar manufacturing processes, is hopeful to be utilized as a cheap carbon source for L-lactic acid fermentation. Considering that cane molasses contains nutrients and hazardous substances, efficient production of L-lactic acid was developed by using a co-feeding strategy based on the utilization of cane molasses/glucose carbon sources. Based on the medium optimization with response surface method, 168.3g/L L-lactic acid was obtained by a Bacillus coagulans strain H-1 after 78h fed-batch fermentation, with a productivity of 2.1g/Lh and a yield of 0.88g/g. Since cane molasses is a feasible carbon source, the co-feeding fermentation might be a promising alternative for the economical production of L-lactic acid. PMID:24333698

  13. The impact of lactic acid bacteria on sourdough fermentation

    OpenAIRE

    Savić Dragiša S.; Joković Nataša

    2005-01-01

    The baking of sourdough breads represents one of the oldest biotechnological processes. Despite traditionality, sourdough bread has great potential because of its benefits. Sourdough is a mixture of flour and water that is dominated by a complex microflora composed of yeasts and lactic acid bacteria that are crucial in the preparation of bread dough. Lactic acid bacteria cause acidification by producing lactic acid that increases the shelf life of bread by preventing the growth of undesirable...

  14. Simultaneous Saccharification and Fermentation of Corn Straw to Lactic Acid

    OpenAIRE

    Wang, Q; Zou, D.(Boston University, Boston, USA); Ma, H; Y. Ji; Wang, X.

    2010-01-01

    The utilization of corn straw to produce lactic acid could largely save the resource as well as decrease the amount of agricultural waste. In this study, orthogonal experimental design was adopted to investigate the optimum conditions for cellulase production from corn straw, and then the cellulase was further used to produce lactic acid through simultaneous saccharification and fermentation (SSF) process. (NH4)2SO4 and Tween 80 were also used to test their effects on lactic acid productio...

  15. Treatment of Lactic Acidosis with Dichloroacetate in Dogs

    OpenAIRE

    Park, Robert; Arieff, Allen I.; Leach, William; Lazarowitz, Virginia C.

    1982-01-01

    Lactic acidosis is a clinical condition due to accumulation of H+ ions from lactic acid, characterized by blood lactate levels >5 mM and arterial pH 60%. Dichloroacetate (DCA) is a compound that lowers blood lactate levels under various conditions in both man and laboratory animals. It acts to increase pyruvate oxidation by activation of pyruvate dehydrogenase. We evaluated the effects of DCA in the treatment of two different models of type B experimental lactic acidosis in diabetic dogs: hep...

  16. Decontamination of Pig Carcasses Using Water Pressure and Lactic Acid

    OpenAIRE

    Jean Carlos Brustolin; Andreia Dal Pisol; Juliana Steffens; Geciane Toniazzo; Eunice Valduga; Marco Di Luccio; Rogério Luis Cansian

    2014-01-01

    The objective of this work was to evaluate the effect of different water pressures and concentrations of lactic acid on microbial counts (mesophilic bacteria, enterobacteria and Salmonella) on pig carcasses without contamination and contaminated carcasses, before and after the last shower and before being cooled. The tests were carried out using 4, 3 and 2 bar water pressure, and 2, 1 and 0% lactic acid concentration. In general, both the pressure in the shower and lactic acid had a positive ...

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

    OpenAIRE

    Dortu, C.; Thonart, Philippe

    2009-01-01

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

  18. Ultrasonic Monitoring of the Progress of Lactic Acid Fermentation

    Science.gov (United States)

    Masuzawa, Nobuyoshi; Kimura, Akihiro; Ohdaira, Etsuzo

    2003-05-01

    Promotion of lactic acid fermentation by ultrasonic irradiation has been attempted. It is possible to determine the progress of fermentation and production of a curd, i.e., yoghurt and or kefir, by measuring acidity using a pH meter. However, this method is inconvenient and indirect for the evaluation of the progress of lactic acid fermentation under anaerobic condition. In this study, an ultrasonic monitoring method for evaluating the progress of lactic acid fermentation was examined.

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

    OpenAIRE

    Douillard, F.P.; Vos, de, W.M.

    2014-01-01

    Genome analysis using next generation sequencing technologies has revolutionized the characterization of lactic acid bacteria and complete genomes of all major groups are now available. Comparative genomics has provided new insights into the natural and laboratory evolution of lactic acid bacteria and their environmental interactions. Moreover, functional genomics approaches have been used to understand the response of lactic acid bacteria to their environment. The results have been instrumen...

  20. Intermediation under Trade Restrictions.

    OpenAIRE

    Winkler, G Michael

    1989-01-01

    Intermediation is the activity of buying and selling simultaneously in one market. In this paper, intermediation in the market for an arbitrary good is derived from trade restrictions in a general equilibrium exchange model. The trade restrictions are given by a trade feasibility relation defined on the set of households, and they necessitate dropping the one price assumption of standard general equilibrium theory. It is shown that, in this setting, equilibria need not exist in spite of well-...

  1. Intermediate algebra a textworkbook

    CERN Document Server

    McKeague, Charles P

    1985-01-01

    Intermediate Algebra: A Text/Workbook, Second Edition focuses on the principles, operations, and approaches involved in intermediate algebra. The publication first takes a look at basic properties and definitions, first-degree equations and inequalities, and exponents and polynomials. Discussions focus on properties of exponents, polynomials, sums, and differences, multiplication of polynomials, inequalities involving absolute value, word problems, first-degree inequalities, real numbers, opposites, reciprocals, and absolute value, and addition and subtraction of real numbers. The text then ex

  2. Intermediate algebra & analytic geometry

    CERN Document Server

    Gondin, William R

    1967-01-01

    Intermediate Algebra & Analytic Geometry Made Simple focuses on the principles, processes, calculations, and methodologies involved in intermediate algebra and analytic geometry. The publication first offers information on linear equations in two unknowns and variables, functions, and graphs. Discussions focus on graphic interpretations, explicit and implicit functions, first quadrant graphs, variables and functions, determinate and indeterminate systems, independent and dependent equations, and defective and redundant systems. The text then examines quadratic equations in one variable, system

  3. Recent advances in lactic acid production by microbial fermentation processes.

    Science.gov (United States)

    Abdel-Rahman, Mohamed Ali; Tashiro, Yukihiro; Sonomoto, Kenji

    2013-11-01

    Fermentative production of optically pure lactic acid has roused interest among researchers in recent years due to its high potential for applications in a wide range of fields. More specifically, the sharp increase in manufacturing of biodegradable polylactic acid (PLA) materials, green alternatives to petroleum-derived plastics, has significantly increased the global interest in lactic acid production. However, higher production costs have hindered the large-scale application of PLA because of the high price of lactic acid. Therefore, reduction of lactic acid production cost through utilization of inexpensive substrates and improvement of lactic acid production and productivity has become an important goal. Various methods have been employed for enhanced lactic acid production, including several bioprocess techniques facilitated by wild-type and/or engineered microbes. In this review, we will discuss lactic acid producers with relation to their fermentation characteristics and metabolism. Inexpensive fermentative substrates, such as dairy products, food and agro-industrial wastes, glycerol, and algal biomass alternatives to costly pure sugars and food crops are introduced. The operational modes and fermentation methods that have been recently reported to improve lactic acid production in terms of concentrations, yields, and productivities are summarized and compared. High cell density fermentation through immobilization and cell-recycling techniques are also addressed. Finally, advances in recovery processes and concluding remarks on the future outlook of lactic acid production are presented. PMID:23624242

  4. Selection of lactic acid bacteria able to ferment inulin hydrolysates

    Directory of Open Access Journals (Sweden)

    Octavian BASTON

    2012-12-01

    Full Text Available Eight homofermentative lactic acid bacteria isolates were tested for lactic acid production using chicory and Jerusalem artichoke hydrolysate as substrate. The pH, lactic acid yield and productivity were used to select the best homolactic bacteria for lactic acid production. The selected strains produced lactic acid at maximum yield after 24 hours of fermentation and the productivity was greater at 24 hours of fermentation. From all studied strains, Lb1 and Lb2 showed the best results regarding lactic acid yields andproductivity. After 48 hours of chicory and Jerusalem artichhoke hydrolysates fermentation, from all the studied strains, Lb2 produced the highest lactic acid yield (0.97%. Lb2 produced after 48 hours of fermentation the lowest pH value of 3.45±0.01. Lb2 showed greater lactic acid productivity compared to the other studied lactic acid bacteria, the highest values, 0.13 g·L-1·h-1fromJerusalem artichoke hydrolysate and 0.11g·L-1·h-1 from chicory hydrolysate, being produced after 24 hours of fermentation.

  5. SCREENING OF BACTERIA FOR LACTIC ACID PRODUCTION FROM WHEY WATER

    Directory of Open Access Journals (Sweden)

    Vethakanraj Helen Shiphrah

    2013-01-01

    Full Text Available Lactobacilli have the property of converting lactose and other sugars to lactic acid through fermentation. So whey water, the greenish translucent liquid rich in lactose, vitamins, proteins and mineral salts, obtained as a by-product after the precipitation of cheese can be used as a substrate for Lactobacilli for lactic acid production which otherwise is a serious environmental pollutant when disposed without pre-treatment. 16 isolates of Lactic acid producing bacteria isolated from various biological sources were inoculated in whey water (1% inoculum and kept at 37°C in the shaker at a speed of 150 revolutions per minute for 36 h. Lactic acid production was estimated after 36 h and the strains 4a, 12a and 15b showed lactic acid production of which 12a produced the highest concentration. The amount of Lactic acid produced by 12a was 0.62 g L-1 under unadjusted condition which is comparable to previously reported strains in enriched medium. So the lactic acid production by strain 12a was further investigated to find the effect of pH and temperature on the production efficiency. Lactic acid production was also checked in Luria-Bertani broth and whey water was found to be the medium of choice for prolonged lactic acid production.

  6. Modeling the continuous lactic acid production process from wheat flour.

    Science.gov (United States)

    Gonzalez, Karen; Tebbani, Sihem; Lopes, Filipa; Thorigné, Aurore; Givry, Sébastien; Dumur, Didier; Pareau, Dominique

    2016-01-01

    A kinetic model of the simultaneous saccharification, protein hydrolysis, and fermentation (SSPHF) process for lactic acid production from wheat flour has been developed. The model describes the bacterial growth, substrate consumption, lactic acid production, and maltose hydrolysis. The model was fitted and validated with data from SSPHF experiments obtained under different dilution rates. The results of the model are in good agreement with the experimental data. Steady state concentrations of biomass, lactic acid, glucose, and maltose as function of the dilution rate were predicted by the model. This steady state analysis is further useful to determine the operating conditions that maximize lactic acid productivity. PMID:26399412

  7. D-Lactic Acidosis in Humans: Review of Update

    OpenAIRE

    Kang, Kyung Pyo; Lee, Sik; Kang, Sung Kyew

    2006-01-01

    D-Lactic acidosis has been well documented in ruminants. In humans, D-lactic acidosis is very rare, but D-lactic acidosis may be more common than generally believed and should be looked for in a case of metabolic acidosis in which the cause of acidosis is not apparent. The clinical presentation of D-lactic acidosis is characterized by episodes of encephalopathy and metabolic acidosis. The entity should be considered as a diagnosis in a patient who presents with metabolic acidosis accompanied ...

  8. THE EFFECTS OF INOCULANT LACTIC ACID BACTERIA ON THE FERMENTATION AND AEROBIC STABILITY OF SUNFLOWER SILAGE

    Directory of Open Access Journals (Sweden)

    Fisun Koc

    2009-12-01

    Full Text Available This study was carried out to determine the effects of actic acid bacterial inoculant on the fermentation and aerobic stability of sunflower silages. Sunflower was harvested at the milk stage. Inoculant-1174 (Pioneer®,USA was used as homofermentative lactic acid bacterial inoculant. Inoculant was applied 6.00 log10 cfu/g silage levels. Silages with no additive served as controls. After treatment, the chopped sunflower was ensiled in the PVC type laboratory silos. Three silos for each group were sampled for chemical and microbiological analysis on days 2, 4, 7, 14, 21, 28 and 56 after ensiling. At the end of the ensiling period, all silages were subjected to an aerobic stability test for 14 days. Neither inoculant improved the fermentation parameters of sunflower silages. At the end of the ensiling period, inoculant increased lactic acid bacteria (LAB and decreased yeast and mould numbers of silages. Inoculant treatment did not affect aerobic stability of silages.

  9. Potential of selected lactic acid bacteria to produce food compatible antifungal metabolites.

    Science.gov (United States)

    De Muynck, Cassandra; Leroy, Annelies I J; De Maeseneire, Sofie; Arnaut, Filip; Soetaert, Wim; Vandamme, Erick J

    2004-01-01

    The aim of this study was to assess the potential of lactic acid bacteria to inhibit the outgrowth of some common food-spoiling fungi. Culture supernatants of 17 Lactic acid bacterial strains as well as of three commercial probiotic cultures were evaluated for antifungal activity using an agar-diffusion method. The method parameters were chosen in order to reveal compounds for potential use in food (bio)preservation. Thirteen strains showed antifungal activity of which five strains were very promising: Lactobacillus acidophilus LMG 9433, L. amylovorus DSM 20532, L. brevis LMG 6906, L. coryniformis subsp. coryniformis LMG 9196 and L. plantarum LMG 6907. Four of these five strains were further examined; it was found that the produced antifungal metabolites were pH-dependent. The exact chemical nature of these substances has not been revealed yet. PMID:15646380

  10. Preparation of poly(lactic acid) composite hollow spheres containing calcium carbonates.

    Science.gov (United States)

    Maeda, Hirotaka; Kasuga, Toshihiro

    2006-07-01

    Poly(lactic acid) composite hollow spheres containing calcium carbonate were prepared by oil-in-water emulsion evaporation to develop injectable bone substitutes incorporated with cells. The spheres were approximately 1.2mm in diameter and had a shell with a thickness in the range of 50-150microm. The hollow in the spheres was presumed to be formed by CO(2) gas generated by the decomposition of vaterite used as a starting material. An open channel approximately 800microm in diameter was formed in the spheres by chemical etching utilizing the rapid dissolution of poly(lactic acid) at the thin portion of the shell. Cells could migrate into the hollow spheres through the open channel and attach to the inner surface. PMID:16765880

  11. Effect of systemic pH on pHi and lactic acid generation in exhaustive forearm exercise

    International Nuclear Information System (INIS)

    To investigate whether changes in systemic pH affect intracellular pH (pHi), energy-rich phosphates, and lactic acid generation in muscle, eight normal volunteers performed exhaustive forearm exercise with arterial blood flow occluded for 2 min on three occasions. Subjects ingested 4 mmol/kg NH4Cl (acidosis; A) or NaHCO3 (alkalosis; B) or nothing (control; C) 3 h before the exercise. Muscle pHi and phosphocreatine (PCr) content were measured with 31P-nuclear magnetic resonance (31P-NMR) spectroscopy during exercise and recovery. Lactate output during 0.5-7 min of recovery was calculated as deep venous-arterial concentration differences times forearm blood flow. Before exercise, blood pH and bicarbonate were lower in acidosis than alkalosis and intermediate in control. Lactic acid output during recovery was less with A than B and intermediate in C. PCr utilization and resynthesis were not affected by extracellular pH changes. pHi did not differ before exercise or at its end. Hence systemic acidosis inhibited and alkalosis stimulated lactic acid output. These findings suggest that systemic pH regulates cellular acid production, protecting muscle pH, at the expense of energy availability

  12. Analysis of intermediate wettability

    Energy Technology Data Exchange (ETDEWEB)

    Skauge, A.; Vik, B.; Spildo, K.; Ottesen, B. [Bergen Univ., Centre for Integrated Petroleum Research, Bergen (Norway)

    2003-09-01

    The fluid flow of porous media petroleum reservoirs is affected by wettability. In general, North Sea sandstone reservoirs fall into the large group of intermediate wet state reservoirs having end point saturation, capillary pressure, and relative permeability properties. This study examined intermediate the wet state by dividing the wet group into three sub-classes defined as fractionally-wet (FW), mixed-wet large (MWL), and mixed-wet small (MWS). Wettability indices were used to group reservoir data into reservoirs with FW, MWL and MWS behaviour. The analysis of wettability data from several North Sea fields showed that 13 reservoirs have sufficient wettability data to determine the state of intermediate wettability. Five of the reservoirs were classified as MWL, 4 as FW and 4 as MWS. Fractional-wet rock was found to have a more robust wettability and cleaned cores maintained a non-water state, suggesting that wetting sites can be coupled to mineralogy in addition to adsorption/deposition of oil components that change the surface properties of the rock. MWS was found to maintain wettability after cleaning, but MWL cores became water wet after solvent cleaning. This study indicates that the type of intermediate wettability has an impact on the data structure required to develop reservoir models. Wettability was found to influence the share of relative permeability curves and the capillary pressure relations in a variety of intermediate wettability classifications. 23 figs.

  13. RECOVERY OF LACTIC ACID FROM AMERICAN CRYSTAL SUGAR COMPANY WASTEWATER; TOPICAL

    International Nuclear Information System (INIS)

    , self-supporting thin films and have, therefore, been used for adhesives, safety glass, and finishes. If the bacterial culture produces the L-lactic acid enanatiomer form exclusively, the L-lactide prepared from this form can be used for making polymers with good fiber-forming properties. We have not currently achieved the exclusive production of L-lactate in our efforts. However, markets in films and structural shapes are available for polymers and copolymers prepared from the mixed D,L-lactide forms that result from processing the D,L-lactic acid obtained from fermentation such as that occurring naturally in sugar beet wastewater. These materials are slowly biodegraded to harmless compounds in the environment, and they burn with a clean blue flame when incinerated. These materials represent excellent opportunities for utilization of the D,L-lactic mixture produced from natural fermentation of the ACS flume water. Esters can be converted into a lactide, and the alcohol released from the ester can be recycled with no net consumption of the alcohol. Lactide intermediates could be produced locally and shipped to polymer producers elsewhere. The polymer and copolymer markets are extremely large, and the role of lactides in these markets is continuously expanding. The overall process can be readily integrated into existing factory wastewater operations. There are several environmental benefits that would be realized at the factories with incorporation of the lactate recovery process. The process reduces the organic loading to the existing wastewater treatment system that should result in enhanced operability with respect to both solids handling and treated-water quality. A higher-quality treated water will also help reduce odor levels from holding ponds. Several water reuse opportunities are probable, depending on the quality of treated water from the FT process

  14. IDENTIFICATION OF INDUSTRIALLY IMPORTANT LACTIC ACID BACTERIA IN FOODSTUFFS

    OpenAIRE

    Prosekov, A.; Babich, O.; Bespomestnykh, K.

    2013-01-01

    Universal genus-specific primers for comparative analysis of two aligned 16S rRNA gene nucleotide sequences of lactic acid bacteria were constructed. The method to identify lactic acid bacteria and a comprehensive plan for their genus and species identification may be used to characterize isolated strains of the Lactobacillus genus bacteria and in quality control of foodstuffs enriched with Lactobacillus.

  15. Fermentation of Fructooligosaccharides by Lactic Acid Bacteria and Bifidobacteria†

    OpenAIRE

    Kaplan, Handan; Hutkins, Robert W.

    2000-01-01

    Lactic acid bacteria and bifidobacteria were screened of their ability to ferment fructooligosaccharides (FOS) on MRS agar. Of 28 strains of lactic acid bacteria and bifidobacteria examined, 12 of 16 Lactobacillus strains and 7 of 8 Bifidobacterium strains fermented FOS. Only strains that gave a positive reaction by the agar method reached high cell densities in broth containing FOS.

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

    NARCIS (Netherlands)

    Douillard, F.P.; Vos, de W.M.

    2014-01-01

    Genome analysis using next generation sequencing technologies has revolutionized the characterization of lactic acid bacteria and complete genomes of all major groups are now available. Comparative genomics has provided new insights into the natural and laboratory evolution of lactic acid bacteria a

  17. Mobile communication and intermediality

    DEFF Research Database (Denmark)

    Helles, Rasmus

    2013-01-01

    The article argues the importance of intermediality as a concept for research in mobile communication and media. The constant availability of several, partially overlapping channels for communication (texting, calls, email, Facebook, etc.) requires that we adopt an integrated view of the various...... communicative affordances of mobile devices in order to understand how people choose between them for different purposes. It is argued that mobile communication makes intermediality especially central, as the choice of medium is detached from the location of stationary media and begins to follow the user across...

  18. Lactic acid and methane: improved exploitation of biowaste potential.

    Science.gov (United States)

    Dreschke, G; Probst, M; Walter, A; Pümpel, T; Walde, J; Insam, H

    2015-01-01

    This feasibility study investigated a two-step biorefining approach to increase the value gained by recycling of organic municipal solid waste. Firstly, lactic acid was produced via batch fermentation at 37°C using the indigenous microbiome. Experiments revealed an optimal fermentation period of 24h resulting in high yields of lactic acid (up to 37gkg(-1)). The lactic acid proportion of total volatile fatty acid content reached up to 83%. Lactobacilli were selectively enriched to up to 75% of the bacterial community. Additionally conversion of organic matter to lactic acid was increased from 22% to 30% through counteracting end product inhibition by continuous lactic acid extraction. Secondly, fermentation residues were used as co-substrate in biomethane production yielding up to 618±41Nmlbiomethaneg(-1) volatile solids. Digestate, the only end product of this process can be used as organic fertilizer. PMID:25460983

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

    International Nuclear Information System (INIS)

    A study was undertaken to determine the effects of certain stress conditions on selected lactic acid bacteria. Where recontamination occurred, lactic acid bacteria was already the dominant bacterial group, with counts of higher than 106/g in vacuum-packaged 'shelf stable' meat products after 1 week storage at 25 and 37 degrees Celsius respectively. Some of the isolates were capable of growing at a pH of 3,9. The minimum pH for growth of a specific culture was dependant on the type of acid that was used to lower the pH. Lactic and acetic acid had the highest inhibitory action. Hydrochloric and citric acid showed similar inhibitory effects, while the effects when using ascorbic acid or gluconic acid for lowering the pH were also fairly similar. Increase in the activity of certain lactic acid bacteria was noticed where the ratio of undissociated to dissociated citric acid in the medium was increased. After exceeding a concentration of 0,048 moles/l undissosiated citric acid in the medium, the activity of the majority of cultures was progressively inhibited. This phenomenon was also found with acetic acid for certain cultures. Selected lactic acid bacteria were resistant to an water activity (a (sub w)) of 0,94 in MRS broth, where NaCl or glycerol was used as a humectant. The minimum a (sub w) for growth was dependent on the type of humectant used. Concentrations of sodium benzoate and potassium sorbate were necessary to inhibit the majority of strains. The % inhibition by sodium benzoate and methyl paraben did not significantly change with a lowering in the pH of the growth medium. Except in the case of lactic acid, the different acids used to lower the pH of the medium did not have a significant effect on the % inhibition by the chemical preservatives. For the cocci, gamma D10 values of between 0,82 and 1,29 kGy were recorded, whereas the lactobacilli were less resistant to gamma rays, with D10 values of between 0,21 and 0,54 kGy

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

    Science.gov (United States)

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

    2015-07-16

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

  1. Intensification of conversion of glucose to lactic acid : equilibria and kinetics for back extraction of lactic acid using trimethylamine

    NARCIS (Netherlands)

    Wasewar, Kailas L.; Heesink, A. Bert M.; Versteeg, Geert F.; Pangarkar, Vishwas G.

    2004-01-01

    Alamine 336 is an effective extractant for the recovery of lactic acid from aqueous solutions. An approach for regeneration and product recovery from such extracts is to back extract lactic acid with a water soluble, volatile tertiary amine such as trimethyl amine. Equilibrium data are presented tha

  2. Room-temperature intermediate layer bonding for microfluidic devices

    NARCIS (Netherlands)

    Bart, J.; Tiggelaar, R.; Yang, M.L.; Schlautmann, S.; Zuilhof, H.; Gardeniers, H.

    2009-01-01

    In this work a novel room-temperature bonding technique based on chemically activated Fluorinated Ethylene Propylene (FEP) sheet as an intermediate between chemically activated substrates is presented. Surfaces of silicon and glass substrates are chemically modified with APTES bearing amine terminal

  3. Hispanic American Heritage, Intermediate.

    Science.gov (United States)

    Shepherd, Mike

    This resource book features the cultural heritage of Hispanics living within the United States and includes ideas, materials, and activities to be used with students in the intermediate grades and middle school. This book explores the definition of the term "Hispanic Americans" and suggests a multilayered population with a variety of cultural…

  4. Water oxidation: Intermediate identification

    Science.gov (United States)

    Cowan, Alexander J.

    2016-08-01

    The slow kinetics of light-driven water oxidation on haematite is an important factor limiting the material's efficiency. Now, an intermediate of the water-splitting reaction has been identified offering hope that the full mechanism will soon be resolved.

  5. GLOSSARY TO INTERMEDIATE HINDI.

    Science.gov (United States)

    Wisconsin Univ., Madison. Indian Language and Area Center.

    INCLUDED IN THIS GLOSSARY ARE THE VOCABULARY ITEMS FOR THE READINGS IN "INTERMEDIATE HINDI." THE ITEMS ARE ARRANGED BY SELECTION IN SERIAL ORDER. EACH ENTRY INCLUDES NAGARI (DEVANAGARI) SCRIPT SPELLING, A NOTATION OF THE FORM CLASS, AND A SHORT ENGLISH GLOSS. THESE TWO VOLUMES ARE ALSO AVAILABLE AS A SET FOR $7.00 FROM THE COLLEGE PRINTING…

  6. Potential of Lactic Streptococci to Produce Bacteriocin

    Science.gov (United States)

    Geis, Arnold; Singh, Jasjit; Teuber, Michael

    1983-01-01

    A survey was made on the bacteriocin-producing potential of lactic streptococci. Bacteriocin-like activities were isolated and partially purified from about 5% of the 280 strains investigated. The frequency of production varied from about 1% in Streptococcus lactis subsp. diacetylactis to 9 and 7.5% in S. lactis and Streptococcus cremoris, respectively. Eight strains of S. cremoris produced bacteriocins which, on the basis of heat stability at different pH values and inhibitory spectrum, could be divided into four types. From 54 S. lactis strains, 5 strains produced inhibitory substances, namely, three nisin-like antibiotics and two different bacteriocins. Only 1 of 93 S. lactis subsp. diacetylactis strains produced a bacteriocin which was very similar to bacteriocins of type I in S. cremoris. All of the bacteriocins that were partially purified by ammonium sulfate precipitation showed very limited inhibitory spectra. Most of the lactic streptococci and a few members of the genera Clostridium, Leuconostoc, and Pediococcus were inhibited. None of the bacteriocins acted on gram-negative bacteria. The bacteriocinogenic strains were also characterized on the basis of plasmid content. All strains possessed between one and nine plasmids ranging from 1 to 50 megadaltons. Images PMID:16346166

  7. Freeze-drying of lactic acid bacteria.

    Science.gov (United States)

    Fonseca, Fernanda; Cenard, Stéphanie; Passot, Stéphanie

    2015-01-01

    Lactic acid bacteria are of great importance for the food and biotechnology industry. They are widely used as starters for manufacturing food (e.g., yogurt, cheese, fermented meats, and vegetables) and probiotic products, as well as for green chemistry applications. Freeze-drying or lyophilization is a convenient method for preservation of bacteria. By reducing water activity to values below 0.2, it allows long-term storage and low-cost distribution at suprazero temperatures, while minimizing losses in viability and functionality. Stabilization of bacteria via freeze-drying starts with the addition of a protectant solution to the bacterial suspension. Freeze-drying includes three steps, namely, (1) freezing of the concentrated and protected cell suspension, (2) primary drying to remove ice by sublimation, and (3) secondary drying to remove unfrozen water by desorption. In this chapter we describe a method for freeze-drying of lactic acid bacteria at a pilot scale, thus allowing control of the process parameters for maximal survival and functionality recovery. PMID:25428024

  8. Preparation and Characterization of Films Extruded of Polyethylene/Chitosan Modified with Poly(lactic acid

    Directory of Open Access Journals (Sweden)

    Jesús Manuel Quiroz-Castillo

    2014-12-01

    Full Text Available The use of mixtures of synthetic and natural polymers is a potential option to reduce the pollution by plastic waste. In this work, the method for the chemical modification of chitosan with poly(lactic acid was developed; then, the preparation of films of blends of polyethylene and chitosan-poly(lactic acid produced by an extrusion method using polyethylene-graft maleic anhydride as a compatibilizer. It was possible to obtain films with a maximum content of 20 wt% and 30 wt%, chitosan, with and without compatibilizer, respectively. Scanning electron microscope (SEM analysis showed a homogeneous surface on all films. The addition of the compatibilizer had a significant effect on the mechanical properties of the films, such as an increase in Young’s modulus and a decrease in the elongation at break; additionally, the compatibilizer promotes thermal degradation in a single step and gives the film a slight increase in thermal resistance. These results are attributed to an improved interaction in the interface of polyethylene and chitosan-poly(lactic acid, promoted by the compatibilizer.

  9. ISOLATION AND IDENTIFICATION OF LACTIC ACID PRODUCING BACTERIA FROM CAMEL MILK

    Directory of Open Access Journals (Sweden)

    Toqeer Ahmad, Rashida Kanwal, Izhar Hussain Athar1, Najam Ayub

    2002-03-01

    Full Text Available Lactic acid bacteria (LAB were isolated from camel milk by culturing the camel milk on specific media and pure culture was obtained by sub culturing. Purification of culture was confirmed by Gram's staining and identified by different bio-chemical tests. Camel milk contains lactic acid producing bacteria including Strpptococci such as S. cremoris and S. lactis and Lactobacilli such as L. acidophilus L. acidophilus grows more rapidly in camel milk than others as its growth is supported by camel milk. A variety of food can be preserved by lactic acid fermentation, so starter culture was prepared from strains which were isolated from camel milk. Camel and buffalo's milk cheese was prepared by using starter culture. The strains isolated from camel milk were best for acid production and can coagulate the milk in less lime. Camel milk cheese was prepared and compared with buffalo's milk cheese. It is concluded that cheese can be prepared successfully from camel milk and better results can be obtained by coagulating milk with starter culture.

  10. Combination of membrane technologies for purification of L (+) - lactic acid from juice of banana (Musa AAA, variety Cavendish cultivar Gram naine) obtained from an agroindustrial waste

    International Nuclear Information System (INIS)

    The process that has allowed recovery and purification of the L (+)-acid present in the juice fermented waste produced from banana was developed, treated enzymatically, using tangential nanofiltration. The effect of the enzymatic treatment was evaluated on physical chemical parameters of fermented banana juice. The process parameters of centrifugal clarification and microfiltration were characterized on banana juice as activities prior operations to recovery and purification of lactic acid. The temperature and the transmembrane pressure on the permeate flow and the performance of recovery and purification of lactic acid were evaluated by the ultrafiltration and nanofiltration processes. The properties physico-chemical the banana juice fermented and of the liquid filtrate obtained at the stage recovery and purification of lactic acid were compared by ultrafiltration

  11. Characteristics of lactic acid bacteria isolates and their effect on silage fermentation of fruit residues.

    Science.gov (United States)

    Yang, Jinsong; Tan, Haisheng; Cai, Yimin

    2016-07-01

    The natural lactic acid bacteria (LAB) population, chemical composition, and silage fermentation of fruit residues were studied. Eighty-two strains of LAB were isolated from fruit residues such as banana leaf and stem, pineapple peel, and papaya peel. All strains were gram-positive and catalase-negative bacteria, and they were divided into 7 groups (A-G) according to morphological and biochemical characters. Strains in groups A to F were rods, and group G was cocci. Group F produced gas from glucose; other groups did not. Groups A to C and F formed dl-lactic acid, whereas groups D, E, and G formed l-lactic acid. Based on the 16S rRNA gene sequence and DNA-DNA hybridization analysis, groups A to G strains were identified as Lactobacillus plantarum (54.9% of the total isolates), Lactobacillus paraplantarum (3.6%), Lactobacillus nagelii (8.5%), Lactobacillus perolens (4.9%), Lactobacillus casei (11.0%), Lactobacillus fermentum (9.8%), and Enterococcus gallinarum (7.3%), respectively. Lactobacillus plantarum and Lactobacillus casei are the most frequently isolated from fruit residues as a dominant species, and they could grow at a lower pH conditions and produce more lactic acid than other isolates. Pineapple and papaya peels contained higher crude protein (11.5-13.8%) and water-soluble carbohydrate (16.8-22.4%), but lower acid detergent fiber contents (21.2 to 26.4%) than banana stems and leaves (8.2% crude protein, 42.8% acid detergent fiber, and 5.1% water-soluble carbohydrate). Compared with banana stem and leaf silages, the pineapple and papaya peel silages were well preserved with a lower pH and higher lactate content. The study suggests that the fruit residues contain excellent LAB species and abundant feed nutrients, and that they can be preserved as silage to be potential food resources for livestock. PMID:27108171

  12. The Intermediate Neutrino Program

    CERN Document Server

    Adams, C; Ankowski, A M; Asaadi, J A; Ashenfelter, J; Axani, S N; Babu, K; Backhouse, C; Band, H R; Barbeau, P S; Barros, N; Bernstein, A; Betancourt, M; Bishai, M; Blucher, E; Bouffard, J; Bowden, N; Brice, S; Bryan, C; Camilleri, L; Cao, J; Carlson, J; Carr, R E; Chatterjee, A; Chen, M; Chen, S; Chiu, M; Church, E D; Collar, J I; Collin, G; Conrad, J M; Convery, M R; Cooper, R L; Cowen, D; Davoudiasl, H; De Gouvea, A; Dean, D J; Deichert, G; Descamps, F; DeYoung, T; Diwan, M V; Djurcic, Z; Dolinski, M J; Dolph, J; Donnelly, B; Dwyer, D A; Dytman, S; Efremenko, Y; Everett, L L; Fava, A; Figueroa-Feliciano, E; Fleming, B; Friedland, A; Fujikawa, B K; Gaisser, T K; Galeazzi, M; Galehouse, D C; Galindo-Uribarri, A; Garvey, G T; Gautam, S; Gilje, K E; Gonzalez-Garcia, M; Goodman, M C; Gordon, H; Gramellini, E; Green, M P; Guglielmi, A; Hackenburg, R W; Hackenburg, A; Halzen, F; Han, K; Hans, S; Harris, D; Heeger, K M; Herman, M; Hill, R; Holin, A; Huber, P; Jaffe, D E; Johnson, R A; Joshi, J; Karagiorgi, G; Kaufman, L J; Kayser, B; Kettell, S H; Kirby, B J; Klein, J R; Kolomensky, Yu G; Kriske, R M; Lane, C E; Langford, T J; Lankford, A; Lau, K; Learned, J G; Ling, J; Link, J M; Lissauer, D; Littenberg, L; Littlejohn, B R; Lockwitz, S; Lokajicek, M; Louis, W C; Luk, K; Lykken, J; Marciano, W J; Maricic, J; Markoff, D M; Caicedo, D A Martinez; Mauger, C; Mavrokoridis, K; McCluskey, E; McKeen, D; McKeown, R; Mills, G; Mocioiu, I; Monreal, B; Mooney, M R; Morfin, J G; Mumm, P; Napolitano, J; Neilson, R; Nelson, J K; Nessi, M; Norcini, D; Nova, F; Nygren, D R; Gann, G D Orebi; Palamara, O; Parsa, Z; Patterson, R; Paul, P; Pocar, A; Qian, X; Raaf, J L; Rameika, R; Ranucci, G; Ray, H; Reyna, D; Rich, G C; Rodrigues, P; Romero, E Romero; Rosero, R; Rountree, S D; Rybolt, B; Sanchez, M C; Santucci, G; Schmitz, D; Scholberg, K; Seckel, D; Shaevitz, M; Shrock, R; Smy, M B; Soderberg, M; Sonzogni, A; Sousa, A B; Spitz, J; John, J M St; Stewart, J; Strait, J B; Sullivan, G; Svoboda, R; Szelc, A M; Tayloe, R; Thomson, M A; Toups, M; Vacheret, A; Vagins, M; Van de Water, R G; Vogelaar, R B; Weber, M; Weng, W; Wetstein, M; White, C; White, B R; Whitehead, L; Whittington, D W; Wilking, M J; Wilson, R J; Wilson, P; Winklehner, D; Winn, D R; Worcester, E; Yang, L; Yeh, M; Yokley, Z W; Yoo, J; Yu, B; Yu, J; Zhang, C

    2015-01-01

    The US neutrino community gathered at the Workshop on the Intermediate Neutrino Program (WINP) at Brookhaven National Laboratory February 4-6, 2015 to explore opportunities in neutrino physics over the next five to ten years. Scientists from particle, astroparticle and nuclear physics participated in the workshop. The workshop examined promising opportunities for neutrino physics in the intermediate term, including possible new small to mid-scale experiments, US contributions to large experiments, upgrades to existing experiments, R&D plans and theory. The workshop was organized into two sets of parallel working group sessions, divided by physics topics and technology. Physics working groups covered topics on Sterile Neutrinos, Neutrino Mixing, Neutrino Interactions, Neutrino Properties and Astrophysical Neutrinos. Technology sessions were organized into Theory, Short-Baseline Accelerator Neutrinos, Reactor Neutrinos, Detector R&D and Source, Cyclotron and Meson Decay at Rest sessions.This report summ...

  13. Intermediate energy data

    International Nuclear Information System (INIS)

    Subgroup 13 (SG13) on Intermediate Energy Nuclear data was formed by NEA Nuclear Science Committee to solve common problems of these types of data for nuclear applications. An overview is presented in this final report of the present activities of SG13, including data needs, high-priority nuclear data request list (nuclides), compilation of experimental data, specialists meetings and benchmarks, data formats and data libraries. Some important accomplishments are summarized, and recommendations are presented. (R.P.)

  14. Volatility and Financial Intermediation

    OpenAIRE

    Joshua Aizenman; Andrew Powell

    1997-01-01

    Following the Tequila period, its after-effects in Latin America and recent events in South East Asia, the effect of volatility on emerging market economies has become an important topic of research with the domestic financial intermediation process being advanced as one of the most important transmission mechanisms. At the same time there has been continued interest in issues related to imperfect information and rationing in credit markets. In this paper, we consider an economy where risk ne...

  15. Lactic acid as a new therapeutic peeling agent in the treatment of lifa disease (frictional dermal melanosis

    Directory of Open Access Journals (Sweden)

    Khalifa E Sharquie

    2012-01-01

    Full Text Available Background: Lifa disease (frictional dermal melanosis is a common dermatological problem. Full strength lactic acid has been proved to be effective and safe peeling agent in the treatment of melasma. Objective: To assess the effectiveness and the safety of lactic acid chemical peeling in the treatment of lifa disease. Materials and Methods: This open label therapeutic trial was conducted in Department of Dermatology in Najaf and Baghdad Teaching Hospitals, from March 2007-October 2008. Full strength lactic acid (92%, pH 3.5 was used as a peeling agent. The treatment sessions were done every 2 weeks until the desired response was achieved (but not more than 6 sessions. The response to therapy was evaluated by objective and subjective methods. All patients were followed monthly for 3 months after the last treatment session. Results: 52 patients with typical clinical features of lifa disease were included. All patients were slim with prominent bones and low body mass index, and gave history of using the lifa (washing agent during bathing. The number of sessions ranged from 2-6 sessions. The pigmentation was improved in all patients as revealed by objective and subjective methods, and this response was statistically highly significant. No significant side effects were recorded in all treated patients. The improvement has been sustained without any obvious relapse throughout the follow-up period. Conclusion: Lactic acid peel is a new, non-costly mode of therapy in treating dermal melanosis in patients with lifa disease.

  16. Analysis of microbial community variation during the mixed culture fermentation of agricultural peel wastes to produce lactic acid.

    Science.gov (United States)

    Liang, Shaobo; Gliniewicz, Karol; Gerritsen, Alida T; McDonald, Armando G

    2016-05-01

    Mixed cultures fermentation can be used to convert organic wastes into various chemicals and fuels. This study examined the fermentation performance of four batch reactors fed with different agricultural (orange, banana, and potato (mechanical and steam)) peel wastes using mixed cultures, and monitored the interval variation of reactor microbial communities with 16S rRNA genes using Illumina sequencing. All four reactors produced similar chemical profile with lactic acid (LA) as dominant compound. Acetic acid and ethanol were also observed with small fractions. The Illumina sequencing results revealed the diversity of microbial community decreased during fermentation and a community of largely lactic acid producing bacteria dominated by species of Lactobacillus developed. PMID:26913642

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

    Directory of Open Access Journals (Sweden)

    Carević Milica

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-05-01

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

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

    Science.gov (United States)

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

    2010-04-01

    Polyols are sugar alcohols largely used as sweeteners and they are claimed to have several health-promoting effects (low-caloric, low-glycemic, low-insulinemic, anticariogenic, and prebiotic). While at present chemical synthesis is the only strategy able to assure the polyol market demand, the biotechnological production of polyols has been implemented in yeasts, fungi, and bacteria. Lactic acid bacteria (LAB) are a group of microorganisms particularly suited for polyol production as they display a fermentative metabolism associated with an important redox modulation and a limited biosynthetic capacity. In addition, LAB participate in food fermentation processes, where in situ production of polyols during fermentation may be useful in the development of novel functional foods. Here, we review the polyol production by LAB, focusing on metabolic engineering strategies aimed to redirect sugar fermentation pathways towards the synthesis of biotechnologically important sugar alcohols such as sorbitol, mannitol, and xylitol. Furthermore, possible approaches are presented for engineering new fermentation routes in LAB for production of arabitol, ribitol, and erythritol. PMID:20180114

  20. Optimization of Process Parameters for Reactive Lactic Acid Extraction

    OpenAIRE

    Kahya, E.; E. Bayraktar; MEHMETOĞLU, Ü.

    2001-01-01

    The reactive extraction method was used to separate lactic acid from its aqueous solutions. In this method, the amine in the solvent phase reacts with the lactic acid in the aqueous phase, resulting in the extraction of acid into the organic phase. In this study, Alamine 336 diluted with oleyl alcohol was used as the solvent. The effects of initial lactic acid concentration, pH, temperature, extraction time, stirring rate, the amount of Alamine 336 in oleyl alcohol and the ratio of o...

  1. Corrosion Behavior of Titanium in Artificial Saliva by Lactic Acid

    OpenAIRE

    Qing Qu; Lei Wang; Yajun Chen; Lei Li; Yue He; Zhongtao Ding

    2014-01-01

    As one of the main products produced by oral microorganisms, the role of lactic acid in the corrosion of titanium is very important. In this study, the corrosion behavior of titanium in artificial saliva with and without lactic acid were investigated by open-circuit potentials (OCPs), polarization curves and electrochemical impedance spectroscopy (EIS). OCP firstly increased with the amount of lactic acid from 0 to 3.2 g/L and then tended to decrease from 3.2 to 5.0 g/L. The corrosion of tita...

  2. Production of aroma compounds in lactic fermentations.

    Science.gov (United States)

    Smid, E J; Kleerebezem, M

    2014-01-01

    This review describes recent scientific research on the production of aroma compounds by lactic acid bacteria (LAB) in fermented food products. We discuss the various precursor molecules for the formation of aroma compounds in connection with the metabolic pathways involved. The roles of nonmetabolic properties such as cell lysis are also described in relation to aroma formation. Finally, we provide an overview of the literature on methods to steer and control aroma formation by LAB in mixed culture fermentations. We demonstrate that the technological progress made recently in high-throughput analysis methods has been driving the development of new approaches to understand, control, and steer aroma formation in (dairy) fermentation processes. This currently entails proposing new rules for designing stable, high-performance mixed cultures constituting a selection of strains, which in concert and on the basis of their individual predicted gene contents deliver the required functionalities. PMID:24580073

  3. Anti-listerial inhibitory lactic acid bacteria isolated from commercial cold smoked salmon

    OpenAIRE

    Tome, Elisabetta; Teixeira, Paula; Gibbs, Paul A.

    2006-01-01

    The natural microflora of cold-smoked fish at the end of shelf-life are lactic acid bacteria (LAB). Some of these display a capacity to inhibit spoilage as well as several strains of pathogenic micro-organisms, e.g. Listeria monocytogenes which is isolated frequently from cold-smoked salmon (CSS). Eight batches of sliced vacuum-packed CSS from Norway, Scotland and Spain were collected at retail. Packs were stored at 5 1C and examined for chemical and microbiological characteristic...

  4. Carbon-13 kinetic isotope effects in the decarbonylation of lactic acid of natural isotopic composition in phosphoric acid medium

    International Nuclear Information System (INIS)

    The 13C kinetic isotope effect fractionation in the decarbonylation of lactic acid (LA) of natural isotopic composition by concentrated phosphoric acids (PA) and by 85% H3PO4 has been studied in the temperature interval of 60-150 deg C. The values of the 13C(1) isotope effects in the decarbonylation of lactic acid in 100% H3PO4, in pyrophosphoric acid and in more concentrated phosphoric acids are intermediate between the values calculated assuming that the C(1)-OH bond is broken in the rate-controlling step of dehydration and those calculated for rupture of the carbon-carbon bond in the transition state. In the temperature interval of 90-130 deg C the experimental 13C fractionation factors determined in concentrated PA approach quite closely the 13C fractionation corresponding to C(2)-C(1) bond scission. The 13C(1) kinetic isotope effects in the decarbonylation of LA in 85% orthophosphoric acid in the temperature range of 110-150 deg C coincide with the 13C isotope effects calculated assuming that the frequency corresponding to the C(1)-OH vibration is lost in the transition state of decarbonylation. A change of the mechanism of decarbonylation of LA in going from concentrated PA medium to 85% H3PO4 has been suggested. A possible secondary 18O and a primary18O kinetic isotope effect in decarbonylation of lactic acid in phosphoric acids media have been discussed, too. (author) 21 refs.; 3 tabs

  5. Lactic Acidosis in a Patient with Type 2 Diabetes Mellitus.

    Science.gov (United States)

    Weisberg, Lawrence S

    2015-08-01

    Lactic acidosis occurs when lactate production exceeds its metabolism. There are many possible causes of lactic acidosis, and in any given patient, several causes may coexist. This Attending Rounds presents a case in point. Metformin's role in the pathogenesis of lactic acidosis in patients with diabetes mellitus is complex, as the present case illustrates. The treatment of lactic acidosis is controversial, except for the imperative to remedy its underlying cause. The use of sodium bicarbonate to treat the often alarming metabolic derangements may be quite efficacious in that regard but is of questionable benefit to patients. Renal replacement therapies (RRTs) have particular appeal in this setting for a variety of reasons, but their effect on clinical outcomes is untested. PMID:25762524

  6. Lactic Acid Bacteria Differentially Activate Natural Killer Cells

    DEFF Research Database (Denmark)

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

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

  7. Side Effects of HIV Medicines: HIV and Lactic Acidosis

    Science.gov (United States)

    ... HIV medicines. All HIV medicines in the nucleoside reverse transcriptase inhibitor (NRTI) drug class may cause lactic acidosis, but ... some HIV medicines. HIV medicines in the nucleoside reverse transcriptase inhibitor (NRTI) drug class can cause the body to ...

  8. Arterial Blood Carbonic Acid Inversely Determines Lactic and Organic Acids

    OpenAIRE

    Aiken, Christopher Geoffrey Alexander

    2013-01-01

    Objective: To establish that arterial blood carbonic acid varies inversely with lactic acid in accordance with bicarbonate exchanging for lactate across cell membranes through the anion exchange mechanism to maintain the Gibbs-Donnan equilibrium.

  9. DNA fingerprinting of lactic acid bacteria in sauerkraut fermentations

    Science.gov (United States)

    Previous studies using traditional biochemical methods to study the ecology of commercial sauerkraut fermentations revealed that four lactic acid bacteria species, Leuconostoc mesenteroides, Lactobacillus plantarum, Pediococcus pentosaceus, and Lactobacillus brevis were the primary microorganisms in...

  10. Amino Acid Decarboxylase Activity of Some Lactic Acid Bacteria

    OpenAIRE

    Pelin ERTÜRKMEN; Turhan, İlkay; Öner, Zübeyde

    2015-01-01

    Microorganisms which have decarboxylase activity can form biogenic amine by enzymatic decarboxylation of amino acids in foods. Histamine poisoning results from consumption of foods typically certain types of fish and cheeses that contain unusually high levels of histamine. Therefore, decarboxylase activity is an important problem at the selection of lactic acid bacteria as a starter culture in fermented products. In this study, decarboxylase activities of 161 lactic acid bacteria (LAB) strain...

  11. Effects of Lactic Acid Bacteria Inoculated Fermentation on Pickled Cucumbers

    OpenAIRE

    Xiaoyi Ji; Yuan Wu; Xingzhu Wu; Yonghua Lin; Weiwei Xu; Hui Ruan; Guoqing He

    2013-01-01

    The aim of this study was to determine the effects of Lactic Acid Bacteria (LAB) fermentation on the texture and organic acid of pickled cucumbers. Texture and sensory evaluation as well as a microscopic observation were performed to study the textural differences among fresh cucumber, Spontaneous fermentation (SF) cucumber and LAB Inoculating Fermentation (LABIF) cucumber. Accumulation of seven organic acids i.e., oxalic, tartaric, malic, lactic, acetic, citric and succinic acid during cucum...

  12. Controlled overproduction of proteins by lactic acid bacteria

    OpenAIRE

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

    1997-01-01

    Lactic acid bacteria are widely used in industrial food fermentations, contributing to flavour, texture and preservation of the fermented products. Here we describe recent advances in the development of controlled gene expression systems, which allow the regulated overproduction of any desirable protein by lactic acid bacteria. Some systems benefit from the fact that the expression vectors, marker genes and inducing factors can be used directly in food applications since they are all derived ...

  13. Metformin-induced lactic acidosis: a case series

    OpenAIRE

    Silvestre Joana; Carvalho Susana; Mendes Vitor; Coelho Luis; Tapadinhas Camila; Ferreira Pedro; Povoa Pedro; Ceia Fatima

    2007-01-01

    Abstract Introduction Unlike other agents used in the treatment of type 2 diabetes mellitus, metformin has been shown to reduce mortality in obese patients. It is therefore being increasingly used in higher doses. The major concern of many physicians is a possible risk of lactic acidosis. The reported frequency of metformin related lactic acidosis is 0.05 per 1000 patient-years; some authors advocate that this rate is equal in those patients not taking metformin. Case presentation We present ...

  14. Materials and methods for efficient lactic acid production

    Science.gov (United States)

    Zhou, Shengde; Ingram, Lonnie O'Neal; Shanmugam, Keelnatham T; Yomano, Lorraine; Grabar, Tammy B; Moore, Jonathan C

    2013-04-23

    The present invention provides derivatives of Escherichia coli constructed for the production of lactic acid. The transformed E. coli of the invention are prepared by deleting the genes that encode competing pathways followed by a growth-based selection for mutants with improved performance. These transformed E. coli are useful for providing an increased supply of lactic acid for use in food and industrial applications.

  15. Synthesis of the enantiomers of 3-deuterium labelled lactic acid

    International Nuclear Information System (INIS)

    Both R- and S-enantiomers of 3-monodeuterated lactic acid ([3-2H]-2(R) and 2(S)-hydroxypropanoic acids) were synthesized by regiospecific nucleophilic opening of diastereoisomer epoxides derived from D-mannitol, with lithium aluminium deuteride. Spectroscopic analysis of the product shows a complete deutero-incorporation which makes [3-2H]-lactic acid suitable as an internal standard using gas chromatography-mass spectroscopy. (author)

  16. Flow cytometric assessment of viability of lactic acid bacteria

    OpenAIRE

    Bunthof, C.J.; Bloemen, K.; Breeuwer, P.; Rombouts, F. M.; Abee, T

    2001-01-01

    The viability of lactic acid bacteria is crucial for their applications as dairy starters and as probiotics. We investigated the usefulness of flow cytometry (FCM) for viability assessment of lactic acid bacteria. The esterase substrate carboxyfluorescein diacetate (cFDA) and the dye exclusion DNA binding probes propidium iodide (PI) and TOTO-1 were tested for live/dead discrimination using a Lactococcus, a Streptococcus, three Lactobacillus, two Leuconostoc, an Enterococcus, and a Pediococcu...

  17. Zirconium complexes with lactic acid in the solution and solid states

    Science.gov (United States)

    Demkowicz, Paul Andrew

    Lactic acid complexes of zirconium are used in a great number of industrial applications. Among these is their use as crosslinking agents for hydraulic fracturing fluids used in secondary oil recovery operations. Because of a poor understanding of zirconium lactate complex chemistry and crosslinking reactions, however, the design of superior fluid systems is often not guided by sound chemical principles and leads to empirical guesswork. Zirconium lactate solutions were characterized using Fourier transform infrared (FT-IR) spectroscopy, 1H, 13C, and 17O nuclear magnetic resonance (NMR) spectroscopy, and potentiometry. The results indicate that lactic acid is coordinated bidentate to zirconium via the alcohol and carboxylate groups. The average number of lactate ligands per zirconium ion is approximately 2 and is demonstrated to be relatively constant from pH 4--9. The lability of the lactate complexes increases as the pH is decreased. The NMR data reveal that there are both large and small complex molecules present in solution, with the size of the complex depending on the extent of zirconium hydrolysis. Large complexes consist of lactic acid coordinated to polynuclear zirconium hydroxy ions. The molecular size of these complexes is sufficient to hinder their tumbling in solution and cause broadening of the measured NMR signals. Small complexes involve lactic acid coordinated to hydroxylated species containing fewer zirconium ions, such that the rotational motion in solution is sufficiently rapid to result in narrow NMR signals. Zirconium lactate complexes were precipitated from solution and analyzed in the solid state using FT-IR spectroscopy, 13C magic angle spinning (MAS) NMR spectroscopy, elemental analysis, thermal gravitational analysis, and x-ray diffraction. Two distinct types of crystalline compounds were synthesized with four lactate ligands per zirconium ion. The coordination of lactic acid to zirconium is different in the two compounds, with one showing

  18. The impact of lactic acid bacteria on sourdough fermentation

    Directory of Open Access Journals (Sweden)

    Savić Dragiša S.

    2005-01-01

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

  19. Exploitation of vegetables and fruits through lactic acid fermentation.

    Science.gov (United States)

    Di Cagno, Raffaella; Coda, Rossana; De Angelis, Maria; Gobbetti, Marco

    2013-02-01

    Lactic acid fermentation represents the easiest and the most suitable way for increasing the daily consumption of fresh-like vegetables and fruits. Literature data are accumulating, and this review aims at describing the main features of the lactic acid bacteria to be used for fermentation. Lactic acid bacteria are a small part of the autochthonous microbiota of vegetables and fruits. The diversity of the microbiota markedly depends on the intrinsic and extrinsic parameters of the plant matrix. Notwithstanding the reliable value of the spontaneous fermentation to stabilize and preserve raw vegetables and fruits, a number of factors are in favour of using selected starters. Two main options may be pursued for the controlled lactic acid fermentation of vegetables and fruits: the use of commercial/allochthonous and the use of autochthonous starters. Several evidences were described in favour of the use of selected autochthonous starters, which are tailored for the specific plant matrix. Pro-technological, sensory and nutritional criteria for selecting starters were reported as well as several functional properties, which were recently ascribed to autochthonous lactic acid bacteria. The main features of the protocols used for the manufacture of traditional, emerging and innovative fermented vegetables and fruits were reviewed. Tailored lactic acid bacteria starters completely exploit the potential of vegetables and fruits, which enhances the hygiene, sensory, nutritional and shelf life properties. PMID:23122495

  20. The examination of parameters for lactic acid fermentation and nutritive value of fermented juice of beetroot, carrot and brewer’s yeast autolysate

    Directory of Open Access Journals (Sweden)

    MILAN MAKSIMOVIC

    2004-09-01

    Full Text Available The conditions for lactic acid fermentation based on a mixture of beetoot juice (Beta vulgaris L. and carrot juice (Daucus carota L. and different content of brewer’s yeast autolysate with Lactobacillus plantarum A112 and with Lactobacillus acidophilus NCDO 1748 has been studied. Both cultures showed good biochemical activity in these mixtures. The production of lactic acid has been stimulated using a higher content of brewer’s yeast autolysate. In these mixtures, L. plantarum A112 showed better growth and lactic acid production than L. acidophilus NCDO 1748. From the data obtained through chemical analyses of the fermented products, it can be seen that the mixture of beetroot and carrot juice and brewer’s yeast autolysate is richer in minerals (Ca, P, Fe and b-carotene than fermented beetroot juice with the same content of brewer’s yeast autolysate.

  1. Development of a Method for Detection of Lactic Acid Bacteria Producing Exclusively the l-(+)- Isomer of Lactic Acid

    OpenAIRE

    Jehanno, D.; Thuault, D; Bourgeois, C. M.

    1992-01-01

    A method was developed for the detection and isolation, within a population of lactic acid bacteria, of strains producing exclusively the l-(+)- isomer of lactic acid; the visual detection of colonies of these particular strains can be carried out directly on agar plates (50 to 70 colonies per plate). The method is based on an enzymatic stereospecific reaction involving d-(−)-lactate dehydrogenase and linked to a staining reaction; the diffusion area of the d-(−)- isomer stains red around the...

  2. Lactic acidosis induced by metformin: incidence, management and prevention.

    Science.gov (United States)

    Lalau, Jean-Daniel

    2010-09-01

    Lactic acidosis associated with metformin treatment is a rare but important adverse event, and unravelling the problem is critical. First, this potential event still influences treatment strategies in type 2 diabetes mellitus, particularly in the many patients at risk of kidney failure, in those presenting contraindications to metformin and in the elderly. Second, the relationship between metformin and lactic acidosis is complex, since use of the drug may be causal, co-responsible or coincidental. The present review is divided into three parts, dealing with the incidence, management and prevention of lactic acidosis occurring during metformin treatment. In terms of incidence, the objective of this article is to counter the conventional view of the link between metformin and lactic acidosis, according to which metformin-associated lactic acidosis is rare but is still associated with a high rate of mortality. In fact, the direct metformin-related mortality is close to zero and metformin may even be protective in cases of very severe lactic acidosis unrelated to the drug. Metformin has also inherited a negative class effect, since the early biguanide, phenformin, was associated with more frequent and sometimes fatal lactic acidosis. In the second part of this review, the objective is to identify the most efficient patient management methods based on our knowledge of how metformin acts on glucose/lactate metabolism and how lactic acidosis may occur (at the organ and cellular levels) during metformin treatment. The liver appears to be a key organ for both the antidiabetic effect of metformin and the development of lactic acidosis; the latter is attributed to mitochondrial impairment and subsequent adenosine triphosphate depletion, acceleration of the glycolytic flux, increased glucose uptake and the generation of lactate, which effluxes into the circulation rather than being oxidized further. Haemodialysis should systematically be performed in severe forms of lactic

  3. Antibiotic resistance of lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Bulajić Snežana

    2008-01-01

    Full Text Available Knowledge on the antibiotic resistance of lactic acid bacteria is still limited, possibly because of the large numbers of genera and species encountered in this group, as well as variances in their resistance spectra. The EFSA considers antibiotic resistances, especially transferable resistances, an important decision criterion for determining a strain's QPS status. There are no approved standards for the phenotypic or genotypic evaluation of antibiotic resistances in food isolates. Also, the choice of media is problematic, as well as the specification of MIC breakpoint values as a result of the large species variation and the possible resulting variation in MIC values between species and genera. The current investigations in this field showed that we might end up with a range of different species- or genus-specific breakpoint values that may further increase the current complexity. Another problem associated with safety determinations of starter strains is that once a resistance phenotype and an associated resistance determinant have been identified, it becomes difficult to show that this determinant is not transferable, especially if the resistance gene is not located on a plasmid and no standard protocols for showing genetic transfer are available. Encountering those problems, the QPS system should allow leeway for the interpretations of results, especially when these relate to the methodology for resistance phenotype determinations, determinations of MIC breakpoints for certain genera, species, or strains, the nondeterminability of a genetic basis of a resistance phenotype and the transferability of resistance genes.

  4. Probiotic Lactic Acid Bacteria and Skin Health.

    Science.gov (United States)

    Jeong, Ji Hye; Lee, Chang Y; Chung, Dae Kyun

    2016-10-25

    Human skin is the first defense barrier against the external environment, especially microbial pathogens and physical stimulation. Many studies on skin health with Lactic acid bacteria (LAB) have been published for many years, including prevention of skin disease and improvement of skin conditions. LAB, a major group of gram-positive bacteria, are known to be beneficial to human health by acting as probiotics. Recent studies have shown that LAB and their extracts have beneficial effects on maintenance and improvement of skin health. Oral administration of Lactobacillus delbrueckii inhibits the development of atopic disease. In addition, LAB and LAB extracts are known to have beneficial effects on intestinal diseases, with Lactobacillus plantarum having been shown to attenuate IL-10 deficient colitis. In addition to intestinal health, L. plantarum also has beneficial effects on skin. pLTA, which is lipoteichoic acid isolated from L. plantarum, has anti-photoaging effects on human skin cells by regulating the expression matrix meralloprotionase-1 (MMP-1) expression. While several studies have proposed a relationship between diseases of the skin and small intestines, there are currently no published reviews of the effects of LAB for skin health through regulation of intestinal conditions and the immune system. In this review, we discuss recent findings on the effects of LAB on skin health and its potential applications in beauty foods. PMID:26287529

  5. Microbial granulation for lactic acid production

    DEFF Research Database (Denmark)

    Kim, Dong-Hoon; Lee, Mo-Kwon; Hwang, Yuhoon;

    2016-01-01

    This work investigated the formation of microbial granules to boost the productivity of lactic acid (LA). The flocculated form of LA-producing microbial consortium, dominated by Lactobacillus sp. (91.5% of total sequence), was initially obtained in a continuous stirred-tank reactor (CSTR), which...... was fed with 2% glucose and operated at a hydraulic retention time (HRT) of 12 h and pH 5.0 ± 0.1 under a thermophilic condition (50°C). The mixed liquor in the CSTR was then transferred to an up-flow anaerobic sludge blanket reactor (UASB). The fermentation performance and granulation process were...... monitored with a gradual decrease of HRT from 8.0 to 0.17 h, corresponding to an increase in the substrate loading from 60 to 2,880 g glucose L−1d−1. As the operation continued, the accumulation of biomass in the UASB was clearly observed, which changed from flocculent to granular form with decrease in HRT...

  6. Heat capacity of poly(lactic acid)

    International Nuclear Information System (INIS)

    The heat capacity of poly(lactic acid) (PLA) is reported from T=(5 to 600) K as obtained by differential scanning calorimetry (d.s.c.) and adiabatic calorimetry. The heat capacity of solid PLA is linked to its group vibrational spectrum and the skeletal vibrations, the latter being described by a Tarasov equation with Θ1=574 K, Θ2=Θ3=52 K, and nine skeletal vibrations. The calculated and experimental heat capacities agree to ±3% between T=(5 and 300) K. The experimental heat capacity of liquid PLA can be expressed by Cp(liquid)=(120.17+0.076T) J · K-1 · mol-1 and has been compared to the ATHAS Data Bank, using contributions of other polymers with the same constituent groups. The glass transition temperature of amorphous PLA occurs at T=332.5 K with a change in heat capacity of 43.8 J · K-1 · mol-1. Depending on thermal history, semi-crystalline PLA has a melting endotherm between T=(418 and 432) K with variable heats of fusion. For 100% crystalline PLA, the heat of fusion is estimated to be (6.55 ± 0.02) kJ · mol-1 at T=480 K. With these results, the enthalpy, entropy, and Gibbs function of crystalline and amorphous PLA were obtained. For semi-crystalline samples, one can check changes of crystallinity with temperature and judge the presence of rigid-amorphous fractions

  7. Longitudinal acoustic properties of poly(lactic acid) and poly(lactic-co-glycolic acid)

    International Nuclear Information System (INIS)

    Acoustics offers rich possibilities for characterizing and monitoring the biopolymer structures being employed in the field of biomedical engineering. Here we explore the rudimentary acoustic properties of two common biodegradable polymers: poly(lactic acid) and poly(lactic-co-glycolic acid). A pulse-echo technique is developed to reveal the bulk speed of sound, acoustic impedance and acoustic attenuation of small samples of the polymer across a pertinent temperature range of 0-70 0C. The glass transition appears markedly as both a discontinuity in the first derivative of the speed of sound and a sharp increase in the acoustic attenuation. We further extend our analysis to consider the role of ethanol, whose presence is observed to dramatically modify the acoustic properties and reduce the glass transition temperature of the polymers. Our results highlight the sensitivity of acoustic properties to a range of bulk properties, including visco-elasticity, molecular weight, co-polymer ratio, crystallinity and the presence of plasticizers.

  8. Financial Intermediation and Economic Growth

    OpenAIRE

    Dima, Bogdan; Petru-Eugen OPRIȘ

    2013-01-01

    The paper evaluates the relationship between financial intermediation and the economic growth in the developing economic systems. First, using dataset from 28 countries,between 2001 and 2010 we define a financial intermediation indicator applying EFA method. We use several dimensions of the financial intermediation: Domestic credit provided by banking sector (% of GDP); Domestic credit to private sector (% of GDP); Broad money (% of GDP); Market capitalization of listed companies (% of GDP). ...

  9. Financial Intermediation and Macroeconomic Analysis

    OpenAIRE

    Michael Woodford

    2010-01-01

    Understanding phenomena such as the recent financial crisis, and possible policy responses, requires the use of a macroeconomic framework in which financial intermediation matters for the allocation of resources. Neither standard macroeconomic models that abstract from financial intermediation nor traditional models of the "bank lending channel" are adequate as a basis for understanding the recent crisis. Instead we need models in which intermediation plays a crucial role, but in which interm...

  10. Phenylbutyrate Therapy for Pyruvate Dehydrogenase Complex Deficiency and Lactic Acidosis

    Science.gov (United States)

    Ferriero, Rosa; Manco, Giuseppe; Lamantea, Eleonora; Nusco, Edoardo; Ferrante, Mariella I.; Sordino, Paolo; Stacpoole, Peter W.; Lee, Brendan; Zeviani, Massimo; Brunetti-Pierri, Nicola

    2014-01-01

    Lactic acidosis is a build-up of lactic acid in the blood and tissues, which can be due to several inborn errors of metabolism as well as nongenetic conditions. Deficiency of pyruvate dehydrogenase complex (PDHC) is the most common genetic disorder leading to lactic acidosis. Phosphorylation of specific serine residues of the E1α subunit of PDHC by pyruvate dehydrogenase kinase (PDK) inactivates the enzyme, whereas dephosphorylation restores PDHC activity. We found that phenylbutyrate enhances PDHC enzymatic activity in vitro and in vivo by increasing the proportion of unphosphorylated enzyme through inhibition of PDK. Phenylbutyrate given to C57B6/L wild-type mice results in a significant increase in PDHC enzyme activity and a reduction of phosphorylated E1α in brain, muscle, and liver compared to saline-treated mice. By means of recombinant enzymes, we showed that phenylbutyrate prevents phosphorylation of E1α through binding and inhibition of PDK, providing a molecular explanation for the effect of phenylbutyrate on PDHC activity. Phenylbutyrate increases PDHC activity in fibroblasts from PDHC-deficient patients harboring various molecular defects and corrects the morphological, locomotor, and biochemical abnormalities in the noam631 zebrafish model of PDHC deficiency. In mice, phenylbutyrate prevents systemic lactic acidosis induced by partial hepatectomy. Because phenylbutyrate is already approved for human use in other diseases, the findings of this study have the potential to be rapidly translated for treatment of patients with PDHC deficiency and other forms of primary and secondary lactic acidosis. PMID:23467562

  11. Inhibition of mycotoxin-producing Aspergillus nomius vsc 23 by lactic acid bacteria and Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    R Muñoz

    2010-12-01

    Full Text Available The effect of different fermenting microorganisms on growth of a mycotoxin- producing Aspergillus nomius was assayed. Two lactic acid bacteria, Lactobacillus fermentum and Lactobacillus rhamnosus, and Saccharomyces cerevisiae, all of which are widely used in fermentation and preservation of food, were assayed on their fungus inhibitory properties. Assays were carried out by simultaneous inoculation of one of the possible inhibiting microorganisms and the fungus or subsequent inoculation of one of the microorganisms followed by the fungus. All three microorganisms assayed showed growth inhibition of the mycotoxin-producing Aspergillus strain. L. rhamnosus O236, isolated from sheep milk and selected for its technological properties, showed highest fungal inhibition of the microorganisms assayed. The use of antifungal LAB with excellent technological properties rather than chemical preservatives would enable the food industry to produce organic food without addition of chemical substances.

  12. Inhibition of mycotoxin-producing Aspergillus nomius vsc 23 by lactic acid bacteria and Saccharomyces cerevisiae.

    Science.gov (United States)

    Muñoz, R; Arena, M E; Silva, J; González, S N

    2010-10-01

    The effect of different fermenting microorganisms on growth of a mycotoxin- producing Aspergillus nomius was assayed. Two lactic acid bacteria, Lactobacillus fermentum and Lactobacillus rhamnosus, and Saccharomyces cerevisiae, all of which are widely used in fermentation and preservation of food, were assayed on their fungus inhibitory properties. Assays were carried out by simultaneous inoculation of one of the possible inhibiting microorganisms and the fungus or subsequent inoculation of one of the microorganisms followed by the fungus. All three microorganisms assayed showed growth inhibition of the mycotoxin-producing Aspergillus strain. L. rhamnosus O236, isolated from sheep milk and selected for its technological properties, showed highest fungal inhibition of the microorganisms assayed. The use of antifungal LAB with excellent technological properties rather than chemical preservatives would enable the food industry to produce organic food without addition of chemical substances. PMID:24031582

  13. Influence of different sterilization processes on the properties of commercial poly(lactic acid).

    Science.gov (United States)

    Savaris, M; Santos, V Dos; Brandalise, R N

    2016-12-01

    This study aims at analyzing the modifications in the morphological, physical, chemical and thermal properties of commercial poly(lactic acid) (PLA) films after exposure to five different sterilization processes. Films were obtained by compression molding, hygienized and sterilized by ethylene oxide (SEtO), hydrogen peroxide plasma (SH2O2), saturated steam (SSS), electron beam radiation (SEB) and gamma radiation (SGR). The samples of PLASEtO, PLASH2O2, PLASEB and PLASGR exhibited thermal and physical changes after being submitted to sterilization processes. PLASSS showed morphological, chemical, thermal and physical changes. It is concluded that processes by SEtO, SH2O2, SEB and EGR can be applied for the sterilization of PLA films and the SSS process is not recommended in view of the data obtained and test conditions reported in this study for PLA films. PMID:27612759

  14. Stress Physiology of Lactic Acid Bacteria.

    Science.gov (United States)

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

    2016-09-01

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

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

    OpenAIRE

    Noda, Fumio; HAYASHI, Kazuya; Mizunuma, Takeji

    1980-01-01

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

  16. Synovial fluid lactic acid measurement in the diagnosis and management of septic arthritis.

    OpenAIRE

    Riordan, T; Doyle, D; Tabaqchali, S

    1982-01-01

    An improved method of lactic acid estimation by gas liquid chromatography (GLC) is described. Synovial fluid lactic acid estimation was performed on 52 patients (15 with septic arthritis and 37 with non-septic arthropathies) and compared to routine microbiological methods and white cell counts. Lactic acid was found to be a useful and rapid test for differentiating between septic and non-septic arthritis being markedly raised (greater than 12 mmol/l) in all the septic joints. Raised lactic ac...

  17. Relationship between lactic acid concentration and bacterial spoilage in ground beef.

    OpenAIRE

    Nassos, P S; King, A. D.; Stafford, A E

    1983-01-01

    Lactic acid concentration correlated with organoleptic spoilage of refrigerated, coarsely ground beef stored in casings with low oxygen permeability. The samples were assayed over time for lactic acid concentration, total aerobic plate count, percentage of gram-positive organisms, and pH. Lactic acid increased in all samples, as did the bacterial counts and percentage of gram-positive organisms in the total microflora, the latter representing an increase in the lactic acid-producing bacteria....

  18. Nucleotide Metabolism and its Control in Lactic Acid Bacteria

    DEFF Research Database (Denmark)

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

    2005-01-01

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

  19. Optimal Auditing Under Intermediated Contracting

    OpenAIRE

    Wolfgang Gick

    2004-01-01

    This paper builds on Faure-Grimaud and Martimort’s [Economics Letters 71 (2001) 75-82] analysis of intermediated contracting. I argue that intermediated contracting permits one form of auditing, in which the sub-contract offered to the firm is examined, contingent on the intermediary’s report. Auditing reduces the intermediary’s rent and increases allocative efficiency.

  20. Recent results on intermediate polars

    OpenAIRE

    Hellier, Coel

    1999-01-01

    I review recent activity in the field of intermediate polars, concentrating on: the mode of accretion (disc-fed, disc-overflow or discless); accretion curtains (the transition region and the accretion footprint); X-ray pulse profiles (occultation and absorption effects); accretion columns (mass determinations, line-broadening, the soft X-ray component), and outbursts in intermediate polars.

  1. Masonry. Performance Objectives. Intermediate Course.

    Science.gov (United States)

    Thompson, Moses

    Several intermediate performance objectives and corresponding criterion measures are listed for each of 13 terminal objectives for an intermediate masonry course. These materials, developed for a two-semester (3 hours daily) course, are designed to provide the student with the skills and knowledge necessary for entry level employment in the field…

  2. Welding. Performance Objectives. Intermediate Course.

    Science.gov (United States)

    Vincent, Kenneth

    Several intermediate performance objectives and corresponding criterion measures are listed for each of nine terminal objectives for an intermediate welding course. The materials were developed for a 36-week (3 hours daily) course designed to prepare the student for employment in the field of welding. Electric welding and specialized (TIG & MIG)…

  3. Lactic acid production from xylose by engineered Saccharomyces cerevisiae without PDC or ADH deletion.

    Science.gov (United States)

    Turner, Timothy L; Zhang, Guo-Chang; Kim, Soo Rin; Subramaniam, Vijay; Steffen, David; Skory, Christopher D; Jang, Ji Yeon; Yu, Byung Jo; Jin, Yong-Su

    2015-10-01

    Production of lactic acid from renewable sugars has received growing attention as lactic acid can be used for making renewable and bio-based plastics. However, most prior studies have focused on production of lactic acid from glucose despite that cellulosic hydrolysates contain xylose as well as glucose. Microbial strains capable of fermenting both glucose and xylose into lactic acid are needed for sustainable and economic lactic acid production. In this study, we introduced a lactic acid-producing pathway into an engineered Saccharomyces cerevisiae capable of fermenting xylose. Specifically, ldhA from the fungi Rhizopus oryzae was overexpressed under the control of the PGK1 promoter through integration of the expression cassette in the chromosome. The resulting strain exhibited a high lactate dehydrogenase activity and produced lactic acid from glucose or xylose. Interestingly, we observed that the engineered strain exhibited substrate-dependent product formation. When the engineered yeast was cultured on glucose, the major fermentation product was ethanol while lactic acid was a minor product. In contrast, the engineered yeast produced lactic acid almost exclusively when cultured on xylose under oxygen-limited conditions. The yields of ethanol and lactic acid from glucose were 0.31 g ethanol/g glucose and 0.22 g lactic acid/g glucose, respectively. On xylose, the yields of ethanol and lactic acid were S. cerevisiae without deleting pyruvate decarboxylase, and the formation patterns of fermentations can be altered by substrates. PMID:26043971

  4. Lactic acid production from xylose by engineered Saccharomyces cerevisiae without PDC or ADH deletion

    Science.gov (United States)

    Production of lactic acid from renewable sugars has received growing attention as lactic acid can be used for making renewable and bio-based plastics. However, most prior studies have focused on production of lactic acid from glucose despite cellulosic hydrolysates contain xylose as well as glucose....

  5. 40 CFR 180.1090 - Lactic acid; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Lactic acid; exemption from the... Exemptions From Tolerances § 180.1090 Lactic acid; exemption from the requirement of a tolerance. Lactic acid (2-hydroxypropanoic acid) is exempted from the requirement of a tolerance when used as a plant...

  6. Effect of high pressure on mesophilic lactic fermentation streptococci

    Energy Technology Data Exchange (ETDEWEB)

    Reps, A; Kuzmicka, M; Wisniewska, K [Chair of Food Biotechnology, University of Warmia and Mazury, ul. Heweliusza 1, 10-724 Olsztyn (Poland)], E-mail: arnold.reps@uwm.edu.pl

    2008-07-15

    The research concerned the effect of high pressure on mesophilic lactic fermentation streptococci, present in two cheese-making commercial inocula produced by Christian-Hansen. Water solutions of inocula were pressurized at 50-800 MPa, at room temperature, for 30-120 min. Pressurization at 50-100 MPa slightly increased or reduced the number of lactic streptococci, depending on the inoculum and pressurization time. Pressurization at 200 MPa caused a reduction in the number of streptococci by over 99.9%, whereas the pressure of 400 MPa and above almost completely inactivated streptococci. Pressurization also reduced the dynamics of microorganism growth and acidification, to the degree depending on the pressure.

  7. Metformin-induced lactic acidosis: a case series

    Directory of Open Access Journals (Sweden)

    Silvestre Joana

    2007-10-01

    Full Text Available Abstract Introduction Unlike other agents used in the treatment of type 2 diabetes mellitus, metformin has been shown to reduce mortality in obese patients. It is therefore being increasingly used in higher doses. The major concern of many physicians is a possible risk of lactic acidosis. The reported frequency of metformin related lactic acidosis is 0.05 per 1000 patient-years; some authors advocate that this rate is equal in those patients not taking metformin. Case presentation We present two case reports of metformin-associated lactic acidosis. The first case is a 77 year old female with a past medical history of hypertension and type 2 diabetes mellitus who had recently been prescribed metformin (3 g/day, perindopril and acetylsalicylic acid. She was admitted to the emergency department two weeks later with abdominal pain and psychomotor agitation. Physical examination revealed only signs of poor perfusion. Laboratory evaluation revealed hyperkalemia, elevated creatinine and blood urea nitrogen and mild leukocytosis. Arterial blood gases showed severe lactic acidemia. She was admitted to the intensive care unit. Vasopressor and ventilatory support was initiated and continuous venovenous hemodiafiltration was instituted. Twenty-four hours later, full clinical recovery was observed, with return to a normal serum lactate level. The patient was discharged from the intensive care unit on the sixth day. The second patient is a 69 year old male with a past medical history of hypertension, type 2 diabetes mellitus and ischemic heart disease who was on metformin (4 g/day, glycazide, acetylsalicylic acid and isosorbide dinitrate. He was admitted to the emergency department in shock with extreme bradycardia. Initial evaluation revealed severe lactic acidosis and elevated creatinine and urea. The patient was admitted to the Intensive Care Unit and commenced on continuous venovenous hemodiafiltration in addition to other supportive measures. A

  8. POLYMERIZATION OF LACTIC O-CARBOXYLIC ANHYDRIDE USING ORGANOMETALLIC CATALYSTS

    Institute of Scientific and Technical Information of China (English)

    Xiu-li Zhuang; Hai-yang Yu; Zhao-hui Tang; Kenichi Oyaizu; Hiroyuki Nishide; Xue-si Chen

    2011-01-01

    The ring-opening polymerization of 5-methyl-l,3-dioxolane-2,4-dione (lactic O-earboxylic anhydride, LacOCA) using organometallic complexes, including Co(Ⅲ) complexes with Schiff base ligands, Tin(Ⅱ) alphatates and Al(Ⅲ)complexes with Schiff base ligands, was explored. The polymerization was carried out by treatment of the organometallic complexes with LacOCA in toluene under mild conditions. The corresponding poly(lactic acid) was characterized by spectroscopy and thermal analyses, which revealed insight into the structure of the effective catalyst for the polymerizationof LacOCA.

  9. Intermediate neutron spectrum problems and the intermediate neutron spectrum experiment

    International Nuclear Information System (INIS)

    Criticality benchmark data for intermediate energy spectrum systems does not exist. These systems are dominated by scattering and fission events induced by neutrons with energies between 1 eV and 1 MeV. Nuclear data uncertainties have been reported for such systems which can not be resolved without benchmark critical experiments. Intermediate energy spectrum systems have been proposed for the geological disposition of surplus fissile materials. Without the proper benchmarking of the nuclear data in the intermediate energy spectrum, adequate criticality safety margins can not be guaranteed. The Zeus critical experiment now under construction will provide this necessary benchmark data

  10. Comparative Antifungal Effect of Lactic Acid Bacteria Strains on Penicillium digitatum

    Directory of Open Access Journals (Sweden)

    Adrian Matei

    2015-11-01

    Full Text Available Lactic acid bacteria (LAB are natural alternative to chemical preservatives for fruits. The aim of the research was to select LAB strains with high antifungal activity against Penicillium digitatum for the biopreservation of fruits. The antifungal activity of eight lactic acid bacteria strains has been evaluated against Penicilliuum digitatum isolated from orange, by overlay assay method and by optical microscope examination. The reversion of inhibition zone after 96 h was recorded as a fungistatic effect while those with inhibition zone for at least 7 days were recorded as fungicidal. The antifungal effect of efficient LAB strains was assessed by comparing inhibition of fungal biofilm formation in liquid media. The strains Lpl, Lpa, LAB 13, LAB 15, LAB 43 and LAB 58 presented intense antifungal activity with clear inhibition zones diameter over 20 mm. The microscopy evidenced atypical hyphae and delaying of conidial chain formation. The strains Lpa, LAB 13, LAB 15 fully inhibited the mycelia growth, strains LAB 43 and LAB 58 partly with delaying of biofilm formation on the surface of culture medium. The results of comparative antifungal activity of LAB strains evidenced the highest inhibition of fungal biofilm formation and structural damages of hyphae and spores caused by the strains Lpa, LAB 13 and LAB 15. These strains could be efficient biocontrol agents of Penicillium digitatum in fruits.

  11. Oriented gold ripple-like structures on poly-L-lactic acid

    International Nuclear Information System (INIS)

    Highlights: • We prepared oriented ripple-like structures on polymer surface with thin gold layer. • These structures show preferential orientation over large areas which is unusual for heat induced wrinkling. • Significant electrical and optical anisotropy was observed. • Zeta-potential, XPS, goniometry and ellipsometry suggest formation of gold lines separated by polymer gaps. • Increase in cell growth in comparison with poly-styrene mock was observed. - Abstract: In this paper chemical, morphological, electrical and biological properties of poly-L-lactic acid thin films with gold nanolayers were studied. These samples were examined as-sputtered and annealed at glass transition temperature. Morphological changes of poly-L-lactic films introduced by annealing were studied by means of atomic force microscopy. This method showed formation of oriented ripple-like structures on the surface of the film. X-ray photoelectron spectroscopy, goniometry, ellipsometry, sheet resistance measurement and electrokinetic analysis were used to determine distribution of gold on the surface. Combined data suggests that these ripple-like structures were formed by gold lines with insulating polymer gaps in between. These lines show preferential orientation over large areas and under proper conditions offer simple way to form electrically anisotropic material on large scale. Also cytocompatibility was studied showing increased cell adhesion and proliferation of mouse embryonic fibroblasts offering another use for these easily formed structures

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    The lactic acid bacteria (LAB) are a functionally related group of low-GC Gram-positive bacteria known essentially for their roles in bioprocessing of foods and animal feeds. Due to extensive industrial use and enormous economical value, LAB have been intensively studied and a large body of compr...... food fermentations. Here we discuss recent metabolic engineering strategies to improve particular cellular traits of LAB and to design LAB cell factories for the bioproduction of added value chemicals.......The lactic acid bacteria (LAB) are a functionally related group of low-GC Gram-positive bacteria known essentially for their roles in bioprocessing of foods and animal feeds. Due to extensive industrial use and enormous economical value, LAB have been intensively studied and a large body...... of comprehensive data on their metabolism and genetics was generated throughout the years. This knowledge has been instrumental in the implementation of successful applications in the food industry, such as the selection of robust starter cultures with desired phenotypic traits. The advent of genomics, functional...

  13. Superabsorbent biphasic system based on poly(lactic acid) and poly(acrylic acid)

    Science.gov (United States)

    Sartore, Luciana; Pandini, Stefano; Baldi, Francesco; Bignotti, Fabio

    2016-05-01

    In this research work, biocomposites based on crosslinked particles of poly(acrylic acid), commonly used as superabsorbent polymer (SAP), and poly-L-lactic acid (PLLA) were developed to elucidate the role of the filler (i.e., polymeric crosslinked particles) on the overall physico-mechanical behavior and to obtain superabsorbent thermoplastic products. Samples prepared by melt-blending of components in different ratios showed a biphasic system with a regular distribution of particles, with diameter ranging from 5 to 10 μm, within the PLLA polymeric matrix. The polymeric biphasic system, coded PLASA i.e. superabsorbent poly(lactic acid), showed excellent swelling properties, demonstrating that cross-linked particles retain their superabsorbent ability, as in their free counterparts, even if distributed in a thermoplastic polymeric matrix. The thermal characteristics of the biocomposites evidence enhanced thermal stability in comparison with neat PLLA and also mechanical properties are markedly modified by addition of crosslinked particles which induce regular stiffening effect. Furthermore, in aqueous environments the particles swell and are leached from PLLA matrix generating very high porosity. These new open-pore PLLA foams, produced in absence of organic solvents and chemical foaming agents, with good physico-mechanical properties appear very promising for several applications, for instance in tissue engineering for scaffold production.

  14. Oriented gold ripple-like structures on poly-L-lactic acid

    Energy Technology Data Exchange (ETDEWEB)

    Juřík, Petr, E-mail: petr.jurik@gmail.com [Department of Solid State Engineering, Institute of Chemical Technology, Prague (Czech Republic); Slepička, Petr [Department of Solid State Engineering, Institute of Chemical Technology, Prague (Czech Republic); Mistrík, Jan; Janíček, Petr [Department of Applied Physics and Mathematics, University of Pardubice (Czech Republic); Rimpelová, Silvie [Department of Biochemistry and Microbiology, Institute of Chemical Technology, Prague (Czech Republic); Kolská, Zdeňka [Faculty of Science, University of J. E. Purkyně, Ústí nad Labem (Czech Republic); Švorčík, Václav [Department of Solid State Engineering, Institute of Chemical Technology, Prague (Czech Republic)

    2014-12-01

    Highlights: • We prepared oriented ripple-like structures on polymer surface with thin gold layer. • These structures show preferential orientation over large areas which is unusual for heat induced wrinkling. • Significant electrical and optical anisotropy was observed. • Zeta-potential, XPS, goniometry and ellipsometry suggest formation of gold lines separated by polymer gaps. • Increase in cell growth in comparison with poly-styrene mock was observed. - Abstract: In this paper chemical, morphological, electrical and biological properties of poly-L-lactic acid thin films with gold nanolayers were studied. These samples were examined as-sputtered and annealed at glass transition temperature. Morphological changes of poly-L-lactic films introduced by annealing were studied by means of atomic force microscopy. This method showed formation of oriented ripple-like structures on the surface of the film. X-ray photoelectron spectroscopy, goniometry, ellipsometry, sheet resistance measurement and electrokinetic analysis were used to determine distribution of gold on the surface. Combined data suggests that these ripple-like structures were formed by gold lines with insulating polymer gaps in between. These lines show preferential orientation over large areas and under proper conditions offer simple way to form electrically anisotropic material on large scale. Also cytocompatibility was studied showing increased cell adhesion and proliferation of mouse embryonic fibroblasts offering another use for these easily formed structures.

  15. Ligand Intermediates in Metal-Catalyzed Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Gladysz, John A.

    1999-07-31

    The longest-running goal of this project has been the synthesis, isolation, and physical chemical characterization of homogeneous transition metal complexes containing ligand types believed to be intermediates in the metal-catalyzed conversion of CO/H{sub 2}, CO{sub 2}, CH{sub 4}, and similar raw materials to organic fuels, feedstocks, etc. In the current project period, complexes that contain unusual new types of C{sub x}(carbide) and C{sub x}O{sub y} (carbon oxide) ligands have been emphasized. A new program in homogeneous fluorous phase catalysis has been launched as described in the final report.

  16. Fermentation of L-lactic Acid and Synthesis of Poly(L-lactic acid)%L-乳酸的发酵生产和聚L-乳酸的化学加工

    Institute of Scientific and Technical Information of China (English)

    田康明; 周丽; 陈献忠; 左志锐; 石贵阳; 王正祥

    2011-01-01

    L-lactic acid is widely used in food, pharmaceutical, cosmetic and industrial fields. Recent years, with the constant shortage of fossil resources, many synthetic polymer materials production has been limited. Therefore, L-lactic acid, which is maded based on biomass resources has been widely used for processing into poly L-lactic acid and other environment-friendly biodegradable materials. Due to the increasing demand for L-lactic acid , the efficient production of low-cost L-lactic acid has become particularly important. The breeding of L-lactic acid producing strain, the cheap resources development and utilization for L-lactic acid fermentation, L-lactic acid fermentation process and purification of L-lactic acid products are systematiclly focused on. For strains breeding, a number of excellent L-lactic acid producers have been obtained which can fermented cheap carbon source to lactic acid efficiently, and strains with low nutritional needs were also breeded.However, strains that have the integrated advantages needs to be further breeding; For fermentation substrates,application of a variety of cheap, abundant carbon sources for lactic acid efficiency fermentation have been already developed, but industrial-scale application of these substrates remains to be further studied; For fermentation process , environment-friendly and low labor intensity fermentation process has been developped , but the problem of high cost is still exists. For purification of products, the post-extraction process has been simplified through the production of breeding species with low nutritional requirements and the using of new fermentation process, but the actual applications still under the constraints of the high cost of the fermentation process. Finally, a short review on the chemical processing of poly L-lactic acid and biodegradation of poly L-lactic acid, and some suggestions were given.%L-乳酸广泛应用于食品、医药、日化和工业等各个领域.近年来随着

  17. Technological, physicochemical and sensory characteristics of a Brazilian semi-hard goat cheese (coalho with added probiotic lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Maria Elieidy Gomes de Oliveira

    2012-12-01

    Full Text Available Over the past few years, the use of probiotics, which are capable of exerting beneficial effects on the composition of intestinal microbiota, has increased. Cheeses have been suggested as a better carrier of probiotic bacteria than other fermented milk products. The effect of added cultures of probiotic lactic acid bacteria on the quality of a Brazilian goat semi-hard cheese (coalho was assessed during 21 days of storage at 10 ºC as follows: C1, Lactococcus lactis subsp. lactis and L. lactis subsp. Cremoris (standard cheese; C2, Lactobacillus acidophilus (LA-5; C3, Lactobacillus paracasei (Lactobacillus casei-01; C4, BBifidobacterium lactis (BB12; and C5, L. acidophilus, L. paracasei and B. lactis. Differences in some physico-chemical, experimental texture and proteolysis parameters were found among the assessed cheeses. All of them presented high luminosity (L* with predominance of the yellow component (b*. Numbers of lactic acid bacteria in the cheeses were greater than 10(7 cfu g-1 during storage. Cheeses with the added probiotic strains alone and in co-culture were better accepted than cheeses without the probiotic strains. It is suggested that goat "coalho" cheese could be a potential carrier of probiotic lactic acid bacteria.

  18. Composition dependence of the synergistic effect of nucleating agent and plasticizer in poly(lactic acid: A Mixture Design study

    Directory of Open Access Journals (Sweden)

    M. K. Fehri

    2016-04-01

    Full Text Available Blends consisting of commercial poly(lactic acid (PLA, poly(lactic acid oligomer (OLA8 as plasticizer and a sulfonic salt of a phthalic ester and poly(D-lactic acid as nucleating agents were prepared by melt extrusion, following a Mixture Design approach, in order to systematically study mechanical and thermal properties as a function of composition. The full investigation was carried out by differential scanning calorimetry (DSC, dynamic mechanical thermal analysis (DMTA and tensile tests. The crystallization half-time was also studied at 105 °C as a function of the blends composition. A range of compositions in which the plasticizer and the nucleation agent minimized the crystallization half-time in a synergistic way was clearly identified thanks to the application of the Mixture Design approach. The results allowed also the identification of a composition range to maximize the crystallinity developed during the rapid cooling below glass transition temperature in injection moulding, thus allowing an easier processing of PLA based materials. Moreover the mechanical properties were discussed by correlating them to the chemical structural features and thermal behaviour of blends.

  19. Preparation and properties of nanocomposites based on poly(lactic acid) and functionalized TiO2

    International Nuclear Information System (INIS)

    Inorganic/polymer nanocomposites are significant materials due to their unique combination of properties. Lactic acid (LA) was used to modify the TiO2 surface by the Ti-carboxylic coordination bonds, and LA can chemically bond TiO2 nanoparticles to form functionalized oligomeric-poly(lactic acid)-grafted TiO2 nanoparticles (g-TiO2). The resulting g-TiO2 was added to the poly(lactic acid) (PLA) matrix to prepare PLA/TiO2 nanocomposites via melting processing. The structure and properties of the nanocomposites were subsequently investigated via Fourier transform infrared spectroscopy, gel permeation chromatography, scanning electron microscopy, transmission electron microscopy, polar optical microscopy, differential scanning calorimetry, dynamic rheometer and universal testing machine. The results showed that g-TiO2 nanocomposites had a much lower degree of agglomeration than bare TiO2. The introduction of g-TiO2 into PLA matrix improved the crystallinity of the composites. The functionalized nanoparticles played an important role in improving mechanical properties and reducing the complex viscosity of the nanocomposites due to its unique structure and the reasonable interfacial interaction between the nanoparticles and PLA matrix.

  20. Preparation and properties of nanocomposites based on poly(lactic acid) and functionalized TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Luo Yanbing; Li Wenda; Wang Xiuli; Xu Dayun [Center for Degradable and Flame-Retardant Polymeric Materials (ERCEPM-MoE), College of Chemistry, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610064 (China); Wang Yuzhong, E-mail: yzwang@mail.scu.edu.cn [Center for Degradable and Flame-Retardant Polymeric Materials (ERCEPM-MoE), College of Chemistry, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610064 (China)

    2009-06-15

    Inorganic/polymer nanocomposites are significant materials due to their unique combination of properties. Lactic acid (LA) was used to modify the TiO{sub 2} surface by the Ti-carboxylic coordination bonds, and LA can chemically bond TiO{sub 2} nanoparticles to form functionalized oligomeric-poly(lactic acid)-grafted TiO{sub 2} nanoparticles (g-TiO{sub 2}). The resulting g-TiO{sub 2} was added to the poly(lactic acid) (PLA) matrix to prepare PLA/TiO{sub 2} nanocomposites via melting processing. The structure and properties of the nanocomposites were subsequently investigated via Fourier transform infrared spectroscopy, gel permeation chromatography, scanning electron microscopy, transmission electron microscopy, polar optical microscopy, differential scanning calorimetry, dynamic rheometer and universal testing machine. The results showed that g-TiO{sub 2} nanocomposites had a much lower degree of agglomeration than bare TiO{sub 2}. The introduction of g-TiO{sub 2} into PLA matrix improved the crystallinity of the composites. The functionalized nanoparticles played an important role in improving mechanical properties and reducing the complex viscosity of the nanocomposites due to its unique structure and the reasonable interfacial interaction between the nanoparticles and PLA matrix.

  1. Site characterization for the final disposal of low and intermediate level radioactive wastes (DFDSMA) by physico-chemical properties of the deep ground water and by the transport parameters of the critical radionuclides contained in the wastes

    International Nuclear Information System (INIS)

    For DFDSMA site selection, geological, hydrological studies and transport measurements of the radionuclides contained in wastes were initiated at INR Pitesti in 1996, which led to choose Saligny site in the neighborhood of Cernavoda NPP as optimal. Geologically, the Saligny site appears to be a sedimentary formation covered with quaternary loessoid based on clay and sand deposits. To estimate the radionuclide transport, experiments were carried out to determine the physico-chemical characteristics of the deep ground water and the distribution and diffusion coefficients for the 137 Cs and 60 Co radionuclides. In the first case, pH, the conductivity, the content of solved salts, the concentrations of inter-exchangeable cations and major anions were determined. The physical chemical processes contributing to 137 Cs and 60 Co retaining on the surfaces of the mineral constituting the rocks were evaluated from investigation of the behavior of the solutions of these radionuclides in contact with the cores extracted at various depths (0-80 m) at Saligny site. Distribution coefficients, retardation factors, the migration speed and time were determined for characterizing the radionuclide migration in the intervening soils. The diffusion coefficients were determined by measuring transfer in diffusion cells with samples of loess and clay from Saligny site. The concentration profile was deduced by measuring the activity of the radionuclide in different locations in the sample. The experimental results were used as input data of the codes for performance evaluation of the final repository. The variation in time of the physico-chemical parameters of the deep water, the diffusion and distribution coefficients (Ds, Kd) and the retardation factor (R) for the geological samples for Saligny are given

  2. Enhanced clearance of lactic dehydrogenase-5 in severe combined immunodeficiency (SCID) mice: effect of lactic dehydrogenase virus on enzyme clearance.

    OpenAIRE

    Hayashi, T.; Ozaki, M.; Mori, I; Saito, M; Itoh, T.; Yamamoto, H.

    1992-01-01

    The lactic dehydrogenase (LDH) level in plasma and the clearance of LDH in C.B-17 scid (severe combined immunodeficiency; SCID) mice were compared with those in C.B-17 or BALB/cCrSlc mice with or without lactic dehydrogenase virus (LDV) infection. The resting enzyme level in SCID mice showed little difference from that in C.B-17 or BALB/cCrSlc mice. The degree of increased plasma LDH level in SCID mice was lower than that in C.B-17 and BALB/cCrSlc mice after LDV infection. To assess the mecha...

  3. Composição químico-bromatológica de variedades de cana-de-açúcar (Saccharum spp L. com diferentes ciclos de produção (precoce e intermediário em três idades de corte Chemical composition of sugar cane varieties (Saccharum spp L. with different cycles of production in three cut time

    Directory of Open Access Journals (Sweden)

    Alberto Magno Fernandes

    2003-08-01

    Full Text Available Foram objetivos deste trabalho determinar a composição químico- bromatológica, as frações potencialmente degradável (B2 e indegradável (C da FDN dos carboidratos totais e estimar a repleção ruminal da cana-de-açúcar com diferentes ciclos de produção (precoce e intermediário, em três idades de corte (426, 487 e 549 dias. As análises laboratoriais consistiram na determinação da matéria seca (MS, matéria orgânica, matéria mineral, proteína bruta (PB, extrato etéreo, lignina, fibra em detergente neutro (FDN, FDN corrigida para cinzas e proteína, fibra em detergente ácido (FDA, proteína insolúvel em detergente neutro, proteína insolúvel em detergente ácido e proteína solúvel em detergente neutro. Os nutrientes digestíveis totais (NDT foram calculados por intermédio da composição química. As frações B2, C e a taxa de digestão da fibra, bem como a repleção ruminal, foram estimadas através de parâmetros cinéticos obtidos a partir da incubação in situ. O avanço da idade de corte propiciou aumento nos teores de MS em 9,5%. As variedades intermediárias apresentaram NDT superiores às precoces, as quais destacaram-se pelos mais elevados teores de FDN e FDA, cujos respectivos valores foram 487,56 e 471,03, e 287,87 e 247,54 g/kg MS para as variedades precoces e intermediárias, respectivamente. O NDT aumentou linearmente com a idade de corte, variando de 62,45 a 63,50%; contudo, os teores de FDN e FDA apresentaram comportamento quadrático. As variedades precoces apresentaram maior teor de PB que as intermediárias somente na idade ao corte de 549 dias, contrariamente, o teor de brix foi superior para as variedades intermediárias no último corte. As variedades precoces apresentaram maior repleção ruminal total e menor taxa de digestão da fibra. A fração B2 da fibra, foi reduzida e a C foi linearmente aumentada com a idade das plantas.The objectives of this work were to determine the chemical

  4. Lactic Acid Yield Using Different Bacterial Strains, Its Purification, and Polymerization through Ring-Opening Reactions

    Directory of Open Access Journals (Sweden)

    F. G. Orozco

    2014-01-01

    Full Text Available Laboratory-scale anaerobic fermentation was performed to obtain lactic acid from lactose, using five lactic acid bacteria: Lactococcus lactis, Lactobacillus bulgaricus, L. delbrueckii, L. plantarum, and L. delbrueckii lactis. A yield of 0.99 g lactic acid/g lactose was obtained with L. delbrueckii, from which a final concentration of 80.95 g/L aqueous solution was obtained through microfiltration, nanofiltration, and inverse osmosis membranes. The lactic acid was polymerized by means of ring-opening reactions (ROP to obtain poly-DL-lactic acid (PDLLA, with a viscosity average molecular weight (Mv of 19,264 g/mol.

  5. Chirality Matters: Synthesis and Consumption of the d-Enantiomer of Lactic Acid by Synechocystis sp. Strain PCC6803

    NARCIS (Netherlands)

    S.A. Angermayr; A.D. van der Woude; D. Correddu; R. Kern; M. Hagemann; K.J. Hellingwerf

    2015-01-01

    Both enantiomers of lactic acid, l-lactic acid and d-lactic acid, can be produced in a sustainable way by a photosynthetic microbial cell factory and thus from CO2, sunlight, and water. Several properties of polylactic acid (a polyester of polymerized lactic acid) depend on the controlled blend of t

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

    Science.gov (United States)

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

  7. Lactic acid and Lactates in Health and wellness

    NARCIS (Netherlands)

    Schaafsma, Gertjan; Schreurs, Victor

    2010-01-01

    This review aims to integrate the present state of knowledge on lactate metabolism in human and mammalian physiology as far as it could be subject to nutritional interventions. An integrated view on the nutritional, metabolic and physiological aspects of lactic acid and lactates might open a perspec

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

    NARCIS (Netherlands)

    Wells, J.

    2011-01-01

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

  9. Lactic Acid and Biosurfactants Production from Residual Cellulose Films.

    Science.gov (United States)

    Portilla Rivera, Oscar Manuel; Arzate Martínez, Guillermo; Jarquín Enríquez, Lorenzo; Vázquez Landaverde, Pedro Alberto; Domínguez González, José Manuel

    2015-11-01

    The increasing amounts of residual cellulose films generated as wastes all over the world represent a big scale problem for the meat industry regarding to environmental and economic issues. The use of residual cellulose films as a feedstock of glucose-containing solutions by acid hydrolysis and further fermentation into lactic acid and biosurfactants was evaluated as a method to diminish and revalorize these wastes. Under a treatment consisting in sulfuric acid 6% (v/v); reaction time 2 h; solid liquid ratio 9 g of film/100 mL of acid solution, and temperature 130 °C, 35 g/L of glucose and 49% of solubilized film was obtained. From five lactic acid strains, Lactobacillus plantarum was the most suitable for metabolizing the glucose generated. The process was scaled up under optimized conditions in a 2-L bioreactor, producing 3.4 g/L of biomass, 18 g/L of lactic acid, and 15 units of surface tension reduction of a buffer phosphate solution. Around 50% of the cellulose was degraded by the treatment applied, and the liqueurs generated were useful for an efficient production of lactic acid and biosurfactants using L. plantarum. Lactobacillus bacteria can efficiently utilize glucose from cellulose films hydrolysis without the need of clarification of the liqueurs. PMID:26293409

  10. Lactic acid bacteria in a changing legislative environment

    NARCIS (Netherlands)

    Feord, J.

    2002-01-01

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

  11. Production of Value-added Products by Lactic Acid Bacteria

    Science.gov (United States)

    Lactic acid bacteria (LAB) are a group of facultative anaerobic, catalase negative, nonmotile and nonsporeforming–Gram positive bacteria. Most LAB utilize high energy C sources including monomer sugars to produce energy to maintain cellular structure and function. This anaerobic fermentation proce...

  12. PRODUCTION OF MANNITOL BY LACTIC ACID BACTERIA: A REVIEW

    Science.gov (United States)

    Mannitol, a naturally occurring polyol, can be produced by lactic acid bacteria (LAB) by fermentation. Some homofermentative LAB produce small amounts of mannitol from glucose. Several heterofermentative LAB can produce mannitol effectively from fructose. In this article, a review on mannitol pro...

  13. GAS PERMEATION PROPERTIES OF POLY(LACTIC ACID). (R826733)

    Science.gov (United States)

    AbstractThe need for the development of polymeric materials based on renewable resources has led to the development of poly(lactic acid) (PLA) which is being produced from a feedstock of corn rather than petroleum. The present study examines the permeation of nitrogen...

  14. Identification and characterisation of probiotic lactic acid bacteria

    Czech Academy of Sciences Publication Activity Database

    Španová, A.; Rittich, B.; Horák, Daniel; Dráb, V.; Drbohlav, J.

    Hydebarad : Osmania University, 2008. s. 17. [International Congress on Bioprocesses in Food Industries /3./ & Convention of the Biotech Research Society India /5./. 06.11.2008-08.11.2008, Hyderabad] Institutional research plan: CEZ:AV0Z40500505 Keywords : probiotic lactic acid bacteria Subject RIV: CE - Biochemistry

  15. Effect of monolaurin and lactic acid on Listeria monocytogenes attached to catfish fillets.

    Science.gov (United States)

    Verhaegh, E G; Marshall, D L; Oh, D H

    1996-04-01

    The purpose of this study was to determine the effects of monolaurin and lactic acid, singly or combined, on Listeria monocytogenes attached to catfish fillets. Skinless catfish fillets were inoculated with L. monocytogenes and dip treated in monolaurin and/or lactic acid solution for various time periods. Results showed that monolaurin up to 400 micrograms/ml had no influence on counts. Conversely, lactic acid-treated fillets had reduced counts compared to controls. Dipping in 0.85, 1.70, or 2.55% lactic acid for 30 min reduced counts by 0.9, 1.4, or 1.3 logs, respectively. Extending the dipping time to 60 min resulted in little additional decrease in counts. Combining monolaurin with lactic acid yielded results similar to lactic acid alone. Hence, population reduction ability resides with lactic acid and not monolaurin. PMID:8796441

  16. Enhanced L-(+)-lactic acid production by an adapted strain of Rhizopus oryzae using corncob hydrolysate

    DEFF Research Database (Denmark)

    Bai, Dongmei; Li, S.Z.; Liu, Z.L.;

    2008-01-01

    -added production of a variety of bioproducts. Lactic acid can be used as a precursor for poly-lactic acid production. Although current industrial lactic acid is produced by lactic acid bacteria using enriched medium, production by Rhizopus oryzae is preferred due to its exclusive formation of the-isomer and a...... simple nutrition requirement by the fungus. Production of-L-(+)-lactic acid by R. oryzae using xylose has been reported; however, its yield and conversion rate are poor compared with that of using glucose. In this study, we report an adapted R. oryzae strain HZS6 that significantly improved efficiency of...... substrate utilization and enhanced production of L-(+)-lactic acid from corncob hydrolysate. It increased L-(+)-lactic acid final concentration, yield, and volumetric productivity more than twofold compared with its parental strain. The optimized growth and fermentation conditions for Strain HZS6 were...

  17. Intermediation Costs and Financial Fragility

    OpenAIRE

    Kaplan, Cafer; Salman, Ferhan

    2007-01-01

    This paper studies implications of intermediation costs in credit markets. The presence of intermediation costs increases the amount of risky projects therefore results in financial fragility. Moreover, for an open economy that has a perfectly liberal capital account, prudent firms finance their projects from foreign markets therefore shrinking the domestic credit markets. The theoretical predictions of our model gains support by Turkish data for the 1991 – 2004 period. Data suggests that an ...

  18. Intermediate uveitis and Lyme borreliosis.

    OpenAIRE

    Breeveld, J; Rothova, A.; Kuiper, H

    1992-01-01

    A case of chronic intermediate uveitis and associated classic snowbanking (pars planitis) with severe cystoid macular oedema probably due to Lyme borreliosis is reported. Despite a disease duration of 10 years the patient's ocular symptoms and visual acuity responded promptly to intravenous ceftriaxone treatment. This case demonstrates that periodic reevaluation of patients with intermediate uveitis is necessary to obtain a specific diagnosis which may include Lyme borreliosis.

  19. Wealth, Financial Intermediation and Growth

    OpenAIRE

    Gaytan, Alejandro; Ranci??re, Romain

    2005-01-01

    This paper presents empirical support for the existence of wealth effects in the contribution of financial intermediation to economic growth, and offers a theoretical explanation for these effects. Using GMM dynamic panel data techniques applied to study the growth-promoting effects of financial intermediation, we show that the exogenous contribution of financial development on economic growth has different effects for different levels of income per capita. We find that this contribution is g...

  20. Intermediate Filing in Household Taxation

    OpenAIRE

    Smith, Henry Edward

    1998-01-01

    This article explores an alternative filing system between joint and individual filing, here termed "intermediate filing." Under such a system, instead of allowing couples to "split" their income as joint filers or forcing them to file as individuals, intermediate filing presents couples with a choice of individual filing as a default or fractional splitting. The ratio of the split would govern both tax treatment and property division (broadly defined) on divorce. The article shows that such ...

  1. Lactic acid delays the inflammatory response of human monocytes

    Energy Technology Data Exchange (ETDEWEB)

    Peter, Katrin, E-mail: katrin.peter@ukr.de [Department of Internal Medicine III, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg (Germany); Rehli, Michael, E-mail: michael.rehli@ukr.de [Department of Internal Medicine III, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg (Germany); RCI Regensburg Center for Interventional Immunology, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg (Germany); Singer, Katrin, E-mail: katrin.singer@ukr.de [Department of Internal Medicine III, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg (Germany); Renner-Sattler, Kathrin, E-mail: kathrin.renner-sattler@ukr.de [Department of Internal Medicine III, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg (Germany); Kreutz, Marina, E-mail: marina.kreutz@ukr.de [Department of Internal Medicine III, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg (Germany); RCI Regensburg Center for Interventional Immunology, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg (Germany)

    2015-02-13

    Lactic acid (LA) accumulates under inflammatory conditions, e.g. in wounds or tumors, and influences local immune cell functions. We previously noted inhibitory effects of LA on glycolysis and TNF secretion of human LPS-stimulated monocytes. Here, we globally analyze the influence of LA on gene expression during monocyte activation. To separate LA-specific from lactate- or pH-effects, monocytes were treated for one or four hours with LPS in the presence of physiological concentrations of LA, sodium lactate (NaL) or acidic pH. Analyses of global gene expression profiles revealed striking effects of LA during the early stimulation phase. Up-regulation of most LPS-induced genes was significantly delayed in the presence of LA, while this inhibitory effect was attenuated in acidified samples and not detected after incubation with NaL. LA targets included genes encoding for important monocyte effector proteins like cytokines (e.g. TNF and IL-23) or chemokines (e.g. CCL2 and CCL7). LA effects were validated for several targets by quantitative RT-PCR and/or ELISA. Further analysis of LPS-signaling pathways revealed that LA delayed the phosphorylation of protein kinase B (AKT) as well as the degradation of IκBα. Consistently, the LPS-induced nuclear accumulation of NFκB was also diminished in response to LA. These results indicate that the broad effect of LA on gene expression and function of human monocytes is at least partially caused by its interference with immediate signal transduction events after activation. This mechanism might contribute to monocyte suppression in the tumor environment. - Highlights: • Lactic acid broadly delays LPS-induced gene expression in human monocytes. • Expression of important monocyte effector molecules is affected by lactic acid. • Interference of lactic acid with TLR signaling causes the delayed gene expression. • The profound effect of lactic acid might contribute to immune suppression in tumors.

  2. Type B Lactic Acidosis Associated With Venlafaxine Overdose.

    Science.gov (United States)

    Iragavarapu, Chaitanya; Gupta, Tanush; Chugh, Savneek S; Aronow, Wilbert S; Frishman, William H

    2016-01-01

    Lactic acidosis that is not secondary to tissue hypoperfusion or hypoxemia (type B lactic acidosis) is a rare but potentially fatal condition that has been associated with drugs like metformin, linezolid, and nucleoside reverse-transcriptase inhibitors in patients with HIV. We report the first case of type B lactic acidosis caused by overdose of the serotonin-norepinephrine reuptake inhibitor, venlafaxine. A 55-year-old man with no significant medical history was brought to the emergency department after intentional ingestion of around 80 capsules of venlafaxine (a total dose of over 6000 mg) in an attempt to commit suicide. Complete blood count and comprehensive metabolic panel were unremarkable except for a bicarbonate level of 13 mEq/L and an anion gap of 22 mEq/L. An arterial blood gas revealed a pH of 7.39, partial pressure of CO2 of 19 mm Hg, calculated bicarbonate of 11.5 mEq/L, and a lactate level of 8.6 mmol/L. The patient was started on aggressive intravenous hydration with normal saline along with oral activated charcoal with sorbitol. Repeat laboratory work after 4 hours showed an improvement in anion gap (15 mEq/L) and serum lactate (5.6 mmol/L). The patient remained stable throughout the hospital stay and lactic acidosis resolved in 24 hours. In the absence of hypotension, hypoxemia, kidney or liver dysfunction, myopathy, malignancy, or use of other medications, venlafaxine was the most likely cause of lactic acidosis in our case. Rapid improvement of acidosis was probably related to clearance of the drug. PMID:25405896

  3. Lactic acid delays the inflammatory response of human monocytes

    International Nuclear Information System (INIS)

    Lactic acid (LA) accumulates under inflammatory conditions, e.g. in wounds or tumors, and influences local immune cell functions. We previously noted inhibitory effects of LA on glycolysis and TNF secretion of human LPS-stimulated monocytes. Here, we globally analyze the influence of LA on gene expression during monocyte activation. To separate LA-specific from lactate- or pH-effects, monocytes were treated for one or four hours with LPS in the presence of physiological concentrations of LA, sodium lactate (NaL) or acidic pH. Analyses of global gene expression profiles revealed striking effects of LA during the early stimulation phase. Up-regulation of most LPS-induced genes was significantly delayed in the presence of LA, while this inhibitory effect was attenuated in acidified samples and not detected after incubation with NaL. LA targets included genes encoding for important monocyte effector proteins like cytokines (e.g. TNF and IL-23) or chemokines (e.g. CCL2 and CCL7). LA effects were validated for several targets by quantitative RT-PCR and/or ELISA. Further analysis of LPS-signaling pathways revealed that LA delayed the phosphorylation of protein kinase B (AKT) as well as the degradation of IκBα. Consistently, the LPS-induced nuclear accumulation of NFκB was also diminished in response to LA. These results indicate that the broad effect of LA on gene expression and function of human monocytes is at least partially caused by its interference with immediate signal transduction events after activation. This mechanism might contribute to monocyte suppression in the tumor environment. - Highlights: • Lactic acid broadly delays LPS-induced gene expression in human monocytes. • Expression of important monocyte effector molecules is affected by lactic acid. • Interference of lactic acid with TLR signaling causes the delayed gene expression. • The profound effect of lactic acid might contribute to immune suppression in tumors

  4. Noncovalent Intermediate of Thymidylate Synthase: Fact or Fiction?

    Science.gov (United States)

    Kholodar, Svetlana A; Kohen, Amnon

    2016-07-01

    Thymidylate synthase is an attractive target for antibiotic and anticancer drugs due to its essential role in the de novo biosynthesis of the DNA nucleotide thymine. The enzymatic reaction is initiated by a nucleophilic activation of the substrate via formation of a covalent bond to an active site cysteine. The traditionally accepted mechanism is then followed by a series of covalently bound intermediates, where that bond is only cleaved upon product release. Recent computational and experimental studies suggest that the covalent bond between the protein and substrate is actually quite labile. Importantly, these findings predict the existence of a noncovalently bound bisubstrate intermediate, not previously anticipated, which could be the target of a novel class of drugs inhibiting DNA biosynthesis. Here we report the synthesis of the proposed intermediate and findings supporting its chemical and kinetic competence. These findings substantiate the predicted nontraditional mechanism and the potential of this intermediate as a new drug lead. PMID:27327197

  5. Lactic Acid Bacteria – Friend or Foe? Lactic Acid Bacteria in the Production of Polysaccharides and Fuel Ethanol

    Science.gov (United States)

    Lactic acid bacteria (LAB) have been widely used in the production of fermented foods and as probiotics. Alternan is a glucan with a distinctive backbone structure of alternating a-(1,6) and a-(1,3) linkages produced by the LAB Leuconostoc mesenteroides. In recent years, we have developed improved...

  6. Lactic Acid Bateria - Friend or Foe? Lactic Acid Bacteria in the Production of Polysaccharides and Fuel Ethanol

    Science.gov (United States)

    Lactic acid bacteria (LAB) have been widely used in the production of fermented foods and as probiotics. Alternan is a glucan with a distinctive backbone structure of alternating alpha-(1,6) and alpha-(1,3) linkages produced by the LAB Leuconostoc mesenteroides. In recent years, improved strains f...

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

    Science.gov (United States)

    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...

  8. Biodegradation of poly(lactic acid) and some of its based systems with Trichoderma viride.

    Science.gov (United States)

    Lipsa, Rodica; Tudorachi, Nita; Darie-Nita, Raluca Nicoleta; Oprică, Lacramioara; Vasile, Cornelia; Chiriac, Aurica

    2016-07-01

    The purpose of this study was to assess the biodegradation of poly(lactic acid) (PLA) and some plasticized PLA based systems by Trichoderma viride fungus, in liquid medium and controlled laboratory conditions. The studied systems were achieved using PLA, hydrolyzed collagen (HC) as biological macromolecules and other additives by melt processing procedure. PLA and the systems' biodegradability was examined by the weight losses of the samples (after 7 and 21 days of exposure) and FTIR-ATR, GPC, SEM analyses (after 21 fungus inoculation days). The thermogravimetry (TG-DTG) study showed that the thermostability of the samples decreased after biodegradation and was influenced by the chemical structure of the systems' components. PMID:27064086

  9. Effects of Lactic Acid Bacteria Fermentation on the Quality of Little Yellow Croaker

    Directory of Open Access Journals (Sweden)

    Yuan Wu

    2013-11-01

    Full Text Available This research was to study the effects of lactic acid bacteria fermentation on the quality of little yellow croaker. The effects of the LAB starter composed of Lactobacillus plantarum and Lactobacillus acidophilus on the quality of little yellow croaker were studied through a 72 h fermentation process in this study. During 72 h fermentation at 30°C, little yellow croaker inoculated with the LAB starter not only resulted in a rapid pH decrease and suppression of spoilage bacteria, but also receded chemical changes such as total volatile base nitrogen and biogenic amines, its texture profile and whiteness also satisfying. Besides, Scanning Electron Micrograph (SEM images indicated some microstructure changes in LAB fermentation. The results demonstrated that the LAB starter could be developed as bio-preservatives to improve the quality of little yellow croaker in storage.

  10. Electrospinning of curcumin loaded chitosan/poly (lactic acid) nanofilm and evaluation of its medicinal characteristics

    Science.gov (United States)

    Dhurai, Bhaarathi; Saraswathy, Nachimuthu; Maheswaran, Ramasamy; Sethupathi, Ponnusamy; Vanitha, Palanisamy; Vigneshwaran, Sukumar; Rameshbabu, Venugopal

    2013-12-01

    The curcumin loaded chitosan/poly (lactic acid) (PLA) nanofibers were produced using electrospinning. Box—Behnken experimental design was used for the optimization of variables (-1, 0, + 1 coded level) like chitosan/PLA strength (% w/v), curcumin strength (% w/v) and applied voltage (kV) to obtain uniform fiber diameter. The morphology of nanofibers was shown by SEM. Molecular interactions and the presence of each chemical compound of curcumin loaded chitosan/PLA fibers were characterized by FTIR and EDX analysis. Antioxidant, drug release and in vitro cytotoxicity tests were performed to evaluate the suitability of nanofibers that would be used for wound healing. In vivo wound healing studies on excision and incision wounds created on rat model showed significant reduction of wound area when compared to untreated. The better healing efficiency can be attributed to the presence of curcumin and chitosan.

  11. Biodegradability of poly(lactic-co-glycolic acid) after femtosecond laser irradiation

    Science.gov (United States)

    Shibata, Akimichi; Yada, Shuhei; Terakawa, Mitsuhiro

    2016-06-01

    Biodegradation is a key property for biodegradable polymer-based tissue scaffolds because it can provide suitable space for cell growth as well as tailored sustainability depending on their role. Ultrashort pulsed lasers have been widely used for the precise processing of optically transparent materials, including biodegradable polymers. Here, we demonstrated the change in the biodegradation of a poly(lactic-co-glycolic acid) (PLGA) following irradiation with femtosecond laser pulses at different wavelengths. Microscopic observation as well as water absorption and mass change measurement revealed that the biodegradation of the PLGA varied significantly depending on the laser wavelength. There was a significant acceleration of the degradation rate upon 400 nm-laser irradiation, whereas 800 nm-laser irradiation did not induce a comparable degree of change. The X-ray photoelectron spectroscopy analysis indicated that laser pulses at the shorter wavelength dissociated the chemical bonds effectively, resulting in a higher degradation rate at an early stage of degradation.

  12. Production, properties, and industrial food application of lactic acid bacteria-derived exopolysaccharides.

    Science.gov (United States)

    Zannini, Emanuele; Waters, Deborah M; Coffey, Aidan; Arendt, Elke K

    2016-02-01

    Exopolysaccharides (EPS)-producing lactic acid bacteria (LAB) are industrially important microorganisms in the development of functional food products and are used as starter cultures or coadjutants to develop fermented foods. There is large variability in EPS production by LAB in terms of chemical composition, quantity, molecular size, charge, presence of side chains, and rigidity of the molecules. The main body of the review will cover practical aspects concerning the structural diversity structure of EPS, and their concrete application in food industries is reported in details. To strengthen the food application and process feasibility of LAB EPS at industrial level, a future academic research should be combined with industrial input to understand the technical shortfalls that EPS can address. PMID:26621802

  13. Intermediate ions in the atmosphere

    Science.gov (United States)

    Tammet, Hannes; Komsaare, Kaupo; Hõrrak, Urmas

    2014-01-01

    Intermediate air ions are charged nanometer-sized aerosol particles with an electric mobility of about 0.03-0.5 cm2 V- 1 s- 1 and a diameter of about 1.5-7.5 nm. Intensive studies of new particle formation provided good knowledge about intermediate ions during burst events of atmospheric aerosol nucleation. Information about intermediate ions during quiet periods between the bursts remained poor. The new mobility analyzer SIGMA can detect air ions at concentrations of mobility fractions of about 1 cm- 3 and enables studying intermediate ions during quiet periods. It became evident that intermediate ions always exist in atmospheric air and should be considered an indicator and a mediator of aerosol nucleation. The annual average concentration of intermediate ions of one polarity in Tartu, Estonia, was about 40 cm- 3 while 5% of the measurements showed a concentration of less than 10 cm- 3. The fraction concentrations in logarithmic 1/8-decade mobility bins between 0.1 and 0.4 cm2 V- 1 s- 1 often dropped below 1 cm- 3. The bursts of intermediate ions at stations separated by around 100 km appeared to be correlated. The lifespan of intermediate ions in the atmosphere is a few minutes, and they cannot be carried by wind over long distances. Thus the observed long-range correlation of intermediate ions is explained by simultaneous changes in air composition in widely spaced stations. A certain amount of intermediate ion bursts, predominantly of negative polarity, are produced by the balloelectric effect at the splashing of water drops during rain. These bursts are usually excluded when speaking about new particle formation because the balloelectric particles are assumed not to grow to the size of the Aitken mode. The mobility distribution of balloelectric ions is uniform in shape in all measurements. The maximum is located at a mobility of about 0.2 cm2 V- 1 s- 1, which corresponds to the diameter of particles of about 2.5 nm.

  14. Screening of lactic acid bacteria for their potential as microbial cell factories for bioconversion of lignocellulosic feedstocks

    DEFF Research Database (Denmark)

    Boguta, Anna Monika; Bringel, Francoise; Martinussen, Jan;

    2014-01-01

    lactic acid bacteria was evaluated regarding their properties with respect to the conversion of lignocellulosic feedstocks. The strains were examined for their ability to utilize xylose and arabinose as well as their resistance towards common inhibitors from pretreated lignocellulosic biomass (furan...... derivatives, phenolic compounds, weak acids). Results: Among 296 tested Lactobacillus and Pediococcus strains, 3 L. pentosus, 1 P. acidilactici and 1 P. pentosaceus isolates were found to be both capable of utilizing xylose and arabinose and highly resistant to the key inhibitors from chemically pretreated...

  15. Properties study of poly(l-lactic acid) film modified by blending with flexible poly(tetramethylene glycol)

    International Nuclear Information System (INIS)

    A series of poly(L-lactic acid)/poly(tetramethylene glycol) (PLLA/PTMG) blend films were prepared by casting the polymer blend solution in chloroform. Surface morphologies of the PLLA/PTMG blend films were investigated by scanning electron microscopy (SEM). Thermal, mechanical, and chemical properties of PLLA/PTMG blend films were studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), tensile tests, and surface contact angle tests. It was revealed that the introduction of flexible PTMG could markedly modify the properties of the PLLA films. (author)

  16. Structural and Functional Conversion of Molecular Chaperone ClpB from the Gram-Positive Halophilic Lactic Acid Bacterium Tetragenococcus halophilus Mediated by ATP and Stress▿

    OpenAIRE

    Sugimoto, Shinya; Yoshida, Hiroyuki; Mizunoe, Yoshimitsu; Tsuruno, Keigo; Nakayama, Jiro; Sonomoto, Kenji

    2006-01-01

    In this study, we report the purification, initial structural characterization, and functional analysis of the molecular chaperone ClpB from the gram-positive, halophilic lactic acid bacterium Tetragenococcus halophilus. A recombinant T. halophilus ClpB (ClpBTha) was overexpressed in Escherichia coli and purified by affinity chromatography, hydroxyapatite chromatography, and gel filtration chromatography. As demonstrated by gel filtration chromatography, chemical cross-linking with glutaralde...

  17. Trends in polymer-grade L-lactic acid fermentation by non-food biomass%聚合级L-乳酸的非粮生物质发酵研究进展

    Institute of Scientific and Technical Information of China (English)

    于波; 曾艳; 姜旭; 王丽敏; 马延和

    2013-01-01

    乳酸在化工、医药和食品加工等领域有着广泛的用途.随着聚乳酸产业的兴起,对聚合级L-乳酸的需求量也不断增加.开发低成本的非粮生物质乳酸发酵工艺、实现发酵-分离耦合是降低聚合级L-乳酸成本、摆脱原料价格不断上涨压力的技术趋势.文中简要综述了近2~3年使用非粮生物质发酵生产聚合级L-乳酸的技术进展,并对未来乳酸发酵工艺作了展望.%Lactic acid has a wide range of uses in the chemical, pharmaceutical and food industry. With rapid development of poly (lactic acid) industry, the demand for polymer-grade L-lactic acid is continuously increasing. Developing low-cost, non-food-biomass-lactic-acid fermentation process and the fermentation-separation coupled technology are trends to reduce polymer-grade L-lactic acid production cost. This review summarized the most recent advances in low-cost L-lactic acid fermentation based on the use of non-food biomass, followed by addressing the key issue that might be strategically important for future development of polymer-grade L-lactic acid production in industry.

  18. Salt-inducible promoter derivable from a lactic acid bacterium, and its use in a lactic acid bacterium for production of a desired protein

    NARCIS (Netherlands)

    Sanders, Jan Willem; Kok, Jan; Venema, Gerard; Ledeboer, Adrianus Marinus

    1998-01-01

    The invention provides a salt-inducible promoter present in SEQ ID NO: 10 and derivable from a lactic acid bacterium in isolation from the coding sequence normally controlled by said promoter in a wild-type lactic acid bacterium, with modifications and important parts thereof. Also provided are a re

  19. Complete Genome Sequence of Lactococcus lactis IO-1, a Lactic Acid Bacterium That Utilizes Xylose and Produces High Levels of l-Lactic Acid

    OpenAIRE

    Kato, Hiroaki; Shiwa, Yuh; Oshima, Kenshiro; Machii, Miki; Araya-Kojima, Tomoko; Zendo, Takeshi; Shimizu-Kadota, Mariko; Hattori, Masahira; Sonomoto, Kenji; Yoshikawa, Hirofumi

    2012-01-01

    We report the complete genome sequence of Lactococcus lactis IO-1 (= JCM7638). It is a nondairy lactic acid bacterium, produces nisin Z, ferments xylose, and produces predominantly l-lactic acid at high xylose concentrations. From ortholog analysis with other five L. lactis strains, IO-1 was identified as L. lactis subsp. lactis.

  20. Nuclear Reactions at Intermediate Energies

    CERN Document Server

    Shyam, Radhey

    2015-01-01

    In the domain of Nuclear reactions at intermediate energies, the QCD coupling constant $\\alpha_s$ is large enough ($\\sim$ 0.3 - 0.5) to render the perturbative calculational techniques inapplicable. In this regime the quarks are confined into colorless hadrons and it is expected that effective field theories of hadron interactions via exchange of hadrons, provide useful tools to describe such reactions. In this contribution we discuss applications of one such theory, the effective Lagrangian model, in describing the hadronic reactions at intermediate energies whose measurements are the focus of a vast international experimental program.

  1. The influences of elastomer toward degradability of poly (lactic acid)

    Science.gov (United States)

    Kaavessina, Mujtahid; Distantina, Sperisa; Chafidz, Achmad; Fadilah, Al-Zahrani, Saeed M.

    2016-02-01

    Poly (lactic acid)/elastomer blends were prepared via direct injection molding with the different weight fractions of elastomer, namely: 0, 10, 20 and 30 wt%. Degradation test of poly (lactic acid) (PLA) was performed by burial in the soil. The physical appearance and thermal properties of the tested specimens were monitored periodically. The presence of elastomer tended to significantly increase the degradability of PLA after buried for 27 weeks. With 30 wt% elastomer, the color and the surface of specimens become more white and rougher due to the degradation. Differential scanning calorimetry (DSC) was used to evaluate thermal properties and crystallinity of all samples. It was found that the melting temperature decreased as the amount of elastomer increased. The crystallinity showed that the degradation of PLA is occurred firstly in amorphous phase.

  2. Radiation induced crystallinity damage in poly(L-lactic acid)

    International Nuclear Information System (INIS)

    The radiation-induced crystallinity damage in poly(L-lactic acid) (PLLA) in the presence of air and in vacuum, is studied. From the heat of fusion enthalpy values of gamma irradiated samples, some changes on the thermal properties were determined. To identify these changes, first the glass transition temperature (Tg) of L-lactic acid polymers irradiated to various doses in air and vacuum have been investigated and it is found that it is independent of irradiation atmosphere and dose. The fraction of damaged units of PLLA per unit of absorbed energy has been measured. For this purpose, SAXS and differential scanning calorimetry methods were used, and the radiation yield of number of damaged units (G(-u)) is found to be 0.74 and 0.58 for PLLA samples irradiated in vacuum and air, respectively

  3. Radiation induced crystallinity damage in poly(L-lactic acid)

    CERN Document Server

    Kantoglu, O

    2002-01-01

    The radiation-induced crystallinity damage in poly(L-lactic acid) (PLLA) in the presence of air and in vacuum, is studied. From the heat of fusion enthalpy values of gamma irradiated samples, some changes on the thermal properties were determined. To identify these changes, first the glass transition temperature (T sub g) of L-lactic acid polymers irradiated to various doses in air and vacuum have been investigated and it is found that it is independent of irradiation atmosphere and dose. The fraction of damaged units of PLLA per unit of absorbed energy has been measured. For this purpose, SAXS and differential scanning calorimetry methods were used, and the radiation yield of number of damaged units (G(-u)) is found to be 0.74 and 0.58 for PLLA samples irradiated in vacuum and air, respectively.

  4. Quantitative analysis of the lactic acid and acetaldehyde produced by Streptococcus thermophilus and Lactobacillus bulgaricus strains isolated from traditional Turkish yogurts using HPLC.

    Science.gov (United States)

    Gezginc, Y; Topcal, F; Comertpay, S; Akyol, I

    2015-03-01

    The present study was conducted to evaluate the lactic acid- and acetaldehyde-producing abilities of lactic acid bacterial species isolated from traditionally manufactured Turkish yogurts using HPLC. The lactic acid bacterial species purified from the yogurts were the 2 most widely used species in industrial yogurt production: Streptococcus thermophilus and Lactobacillus bulgaricus. These bacteria have the ability to ferment hexose sugars homofermentatively to generate lactic acid and some carbonyl compounds, such as acetaldehyde through pyruvate metabolism. The levels of the compounds produced during fermentation influence the texture and the flavor of the yogurt and are themselves influenced by the chemical composition of the milk, processing conditions, and the metabolic activity of the starter culture. In the study, morphological, biochemical, and molecular characteristics were employed to identify the bacteria obtained from homemade yogurts produced in different regions of Turkey. A collection of 91 Strep. thermophilus and 35 L. bulgaricus strains were investigated for their lactic acid- and acetaldehyde-formation capabilities in various media such as cow milk, LM17 agar, and aerobic-anaerobic SM17 agar or de Man, Rogosa, and Sharpe agar. The amounts of the metabolites generated by each strain in all conditions were quantified by HPLC. The levels were found to vary depending on the species, the strain, and the growth conditions used. Whereas lactic acid production ranged between 0 and 77.9 mg/kg for Strep. thermophilus strains, it ranged from 0 to 103.5 mg/kg for L. bulgaricus. Correspondingly, the ability to generate acetaldehyde ranged from 0 to 105.9 mg/kg in Strep. thermophilus and from 0 to 126.9 mg/kg in L. bulgaricus. Our study constitutes the first attempt to determine characteristics of the wild strains isolated from traditional Turkish yogurts, and the approach presented here, which reveals the differences in metabolite production abilities of the

  5. Lactic acid production of Rhizopus oryzae under different conditions%对米根霉在不同条件下产酸情况的研究

    Institute of Scientific and Technical Information of China (English)

    张燕; 柴振波; 蔡高伟

    2011-01-01

    Lactic acid is one of the three main organic acids in the world, and could be widely used in food, pharmaceuticals, chemicals, leather,textiles, environmental protection, agriculture and many other rields. Lactic acid with high purity could be produced by microbial fermentation.Rhizopus oryzae is important for L-lactic acid production. In this study, the acid production properties of R. oryzae straina isolated in nature were investigated. The reducing sugar and pH were detected, and the L-lactic acid yield was determined by NaOH titration. According to the detection of L-lactic acid production under different conditions, the production conditions were optimized and the lactic acid yield was improved. When 130g/L glucose was added and 2.0g/L ammonium chloride was used as nitrogen source, the optimal yield of L-lactic acid was44.2g/L and the conversion rate of glucose was 40.1%.%乳酸是目前世界上公认的3大有机酸之一,其广泛应用于食品、医药、化工、制革、纺织、环保和农业等诸多领域.用微生物发酵法生产L-乳酸可以达到较高的纯度要求.根霉属中的米根霉(Rhizopus oryzae)是目前发酵生产L-乳酸的重要菌株,本课题研究的是从自然界选取的米根霉在不同条件下的产酸情况.采用分析方法包括还原糖的测定,pH测定,NaOH滴定确定乳酸产量.通过对不同条件下产酸情况的分析,可以优化产酸条件,提高产酸率.最终确定出在葡萄糖浓度为130g/L,氯化铵作为氮源,其浓度在2.og/L的条件下,实验室菌株的最佳产酸量是44.2g/L,葡萄糖的转化率是40.1%.

  6. Lactic acid bacteria fermentations in oat-based suspensions

    OpenAIRE

    Mårtensson, Olof

    2002-01-01

    This thesis deals with the fermentation characteristics of lactic acid bacteria (LAB) in oat-based suspensions, with formulation work of fermented products based on oat and with nutritional studies of these products. Changes in structure in terms of viscosity and ropiness were studied when exopolysaccharide (EPS)-producing LAB strains, namely, Lactobacillus delbrueckii subsp. bulgaricus NCFB 2772, Lactobacillus brevis G-77 and Pediococcus damnosus 2.6 were grown in these oat-based suspensions...

  7. Cell wall structure and function in lactic acid bacteria

    OpenAIRE

    Kulakauskas, Saulius

    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 traditionall...

  8. Modelling of lactic fermentation of carrot slices in salted brines

    OpenAIRE

    Nabais, R.M.; Malcata, F. X.

    1997-01-01

    Increases in suspended biomass and variation in the concentrations of reducing sugars, salt, and lactic acid in brine containing sliced carrots were followed for a period of several days. A tentative unstructured, unsegregated model for the metabolism of suspended Lactobacillus plan tarum coupled with Fick's second law of diffusion for the transport of solutes within the carrot material was postulated. This general model was fitted by non-linear multiresponse regression analysis to an extensi...

  9. Food-grade Selection Markers in Lactic Acid Bacteria

    OpenAIRE

    Song He; Fanghong Gong; Ya'nan Guo; Dechun Zhang.

    2012-01-01

    Lactic acid bacteria (LAB) are generally regarded as safe (GRAS) microorganisms and widely used in industry and medicine. We are trying to add additional properties to them by gene engineering. However, the genetically modified bacteria are not acceptable to use in food and medicine due to the presence of antibiotic resistance genes in plasmids. Thus, it is necessary to develop food-grade selection markers. Food-grade markers can be divided into three classes based on their selected character...

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

    OpenAIRE

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

    2000-01-01

    Lactic acid bacteria (LABs) are widely used in the manufacturing of fermented food and are among the best-studied microorganisms. Detailed knowledge of a number of physiological traits has opened new potential applications for these organisms in the food industry, while other traits might be beneficial for human health. Important new developments have been made in the research of LABs in the areas of multidrug resistance, bacteriocins and quorum sensing, osmoregulation, proteolysis, autolysin...

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

    OpenAIRE

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

    2015-01-01

    In contrast to the honey bee gut, which is colonized by a few characteristic bacterial clades, the hive of the honey bee is home to a diverse array of microbes, including many lactic acid bacteria (LAB). In this study, we used culture, combined with sequencing, to sample the LAB communities found across hive environments. Specifically, we sought to use network analysis to identify microbial hubs sharing nearly identical operational taxonomic units, evidence which may indicate cooccurrence of ...

  12. LACTIC ACID MICROFLORA OF BULGARIAN MILK PRODUCTS FROM MOUNTAIN REGIONS

    OpenAIRE

    Koleva, P.; Georgieva, R.; D. Nikolova; Danova, S.

    2009-01-01

    International audience This study aimed to isolate and characterize viable lactic acid bacteria (LAB) from the most popular in Bulgaria fermented milk products. Different samples from home-made cheeses, yoghurt and katak, from ecological regions of Stara Planina, Rila and Rodopi mountains were collected. A total of 25 LAB cultures (coci and rods) were isolated and polyphasic taxonomic characterization was performed. Eight of the strains from yoghurt were phenotypically similar to Lactobaci...

  13. Highly crystallized poly (lactic acid) under high pressure

    OpenAIRE

    Jin Zhang; Ding-Xiang Yan; Jia-Zhuang Xu; Hua-Dong Huang; Jun Lei; Zhong-Ming Li

    2012-01-01

    Biodegradable poly (lactic acid) (PLA) usually has a crystallinity less than 10% due to its poor crystallization ability. In this work, we found high pressure could significantly facilitate formation of crystallites of PLA, resulting in a crystallinity high up to 66.3% at pressure and temperature of 300 MPa and 185 ºC. High-pressure induced crystalline reorganization and lamellar thickening led to two melting temperatures in the highly crystallized PLA but without cold crystallization compare...

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

    Science.gov (United States)

    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. Research of Sichuan Paocai and Lactic Acid Bacteria

    OpenAIRE

    Chen Gong; Yu Wen-Hua; Zhang Qi-sheng; Song Ping; Zhang Bei-Bei; Liu Zhu; You Jing-gang; Li Heng

    2014-01-01

    Sichuan Paocai with long history is a typical representative of Chinese pickles, which has been inherited for thousands years. Its strong vitality was largely due to its unique microbial fermentation style. In this study, molecular microbial technology and traditional microbial technology were employed to study the distributions and changes of the microorganisms during the fermentation. The results showed that the lactic acid bacteria such as Leuconostoc mesenteroides, Lactobacillus plantarum...

  16. Surface Binding of Aflatoxin B1 by Lactic Acid Bacteria

    OpenAIRE

    Haskard, Carolyn A.; El-Nezami, Hani S.; Kankaanpää, Pasi E.; Salminen, Seppo; Ahokas, Jorma T.

    2001-01-01

    Specific lactic acid bacterial strains remove toxins from liquid media by physical binding. The stability of the aflatoxin B1 complexes formed with 12 bacterial strains in both viable and nonviable (heat- or acid-treated) forms was assessed by repetitive aqueous extraction. By the fifth extraction, up to 71% of the total aflatoxin B1 remained bound. Nonviable bacteria retained the highest amount of aflatoxin B1. Lactobacillus rhamnosus strain GG (ATCC 53103) and L. rhamnosus strain LC-705 (DS...

  17. Poly (lactic acid) organoclay nano composites for paper coating applications

    OpenAIRE

    Tatcha Sonjui; Nantana Jiratumnukul

    2014-01-01

    Poly(lactic acid) or PLA is a well-known biodegradable polymer derived from renewable resources such as corn strach, tapioca strach, and sugar cane. PLA is the most extensively utilized biodegradable polyester with potential to replace conventional petrochemical-based polymers. However, PLA has some drawbacks, such as brittleness and poor gas barrier properties. Nano composite polymers have experience and increasing interest due to their characteristics, especially in mechanical a...

  18. ldentification and Mutagenesis of Lactic Acid Bacteria from Chinese Sauerkraut

    Institute of Scientific and Technical Information of China (English)

    Yajing CHAl; Hao SHl; Ri NA

    2015-01-01

    ln order to analyze the fermentation properties of lactic acid bacteria in Chinese sauerkraut and to improve acid production, 21 samples of Chinese sauerkraut from lnner Mongolia and Northeast China were col ected and isolated with a Man-Rogosa-Sharpe (MRS) culture. Sixteen strains of lactic acid bacteria were identified by combining both phenotype and genotype methods. After activation, the 16 strains were inoculated into the MRS medium with a concentration of 4%and then incubated at 37 ℃. The pH and the absorbance of the culture were mea-sured. The activated strains were then mutagenized in a field of 4 KV/cm mutation, with dosages administered within 20 minutes and 30 minutes, respectively. The variation curves of the pH and the absorbance of the culture were determined. The experimental results showed that the lactic acid bacteria isolated from the soup were identified as Lactobacil us and the acid production of the bacteria was signifi-cantly improved by the mutagenesis of the corona electric field.

  19. Lactic acidosis secondary to metformin overdose: a case report

    Directory of Open Access Journals (Sweden)

    Timbrell Simon

    2012-08-01

    Full Text Available Abstract Introduction Metformin is a commonly used treatment modality in type 2 diabetes mellitus, with a well documented side effect of lactic acidosis. In the intensive care setting lactate and pH levels are regularly used as a useful predictor of poor prognosis. In this article we highlight how high lactate levels are not an accurate predictor of mortality in deliberate metformin overdose. Case presentation We present the case of a 70-year-old Caucasian man who took a deliberate metformin overdose of unknown quantity. He had a profound lactic acidosis at presentation with a pH of 6.93 and a lactate level of more than 20mmol/L. These figures would normally correspond with a mortality of more than 80%; however, with appropriate management this patient’s condition improved. Conclusion We provide evidence that the decision to treat severe lactic acidosis in deliberate metformin overdose should not be based on arterial lactate and pH levels, as would be the case in other overdoses. We also demonstrate that appropriate treatment with hemodiafiltration and 8.4% sodium bicarbonate, even in patients with a very high lactate and low pH, can be successful.

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

    Science.gov (United States)

    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

  1. Probiotication of tomato juice by lactic acid bacteria.

    Science.gov (United States)

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

    2004-12-01

    This study was undertaken to determine the suitability of tomato juice as a raw material for production of probiotic juice by four lactic acid bacteria (Latobacillus acidophilus LA39, Lactobacillus plantarum C3, Lactobacillus casei A4, and Lactobacillus delbrueckii D7). Tomato juice was inoculated with a 24-h-old culture and incubated at 30 degrees C. Changes in pH, acidity, sugar content, and viable cell counts during fermentation under controlled conditions were measured. The lactic acid cultures reduced the pH to 4.1 or below and increased the acidity to 0.65% or higher, and the viable cell counts (CFU) reached nearly 1.0 to 9.0 x 10(9)/ml after 72 h fermentation. The viable cell counts of the four lactic acid bacteria in the fermented tomato juice ranged from 10(6) to 10(8) CFU/ml after 4 weeks of cold storage at 4 degrees C. Probiotic tomato juice could serve as a health beverage for vegetarians or consumers who are allergic to dairy products. PMID:15650688

  2. Lactic acid bacteria isolated from soy sauce mash in Thailand.

    Science.gov (United States)

    Tanasupawat, Somboon; Thongsanit, Jaruwan; Okada, Sanae; Komagata, Kazuo

    2002-08-01

    Fourteen sphere-shaped and 30 rod-shaped lactic acid bacteria were isolated from soy sauce mash of two factories in Thailand. These strains were separated into two groups, Group A and Group B, by cell shape and DNA-DNA similarity. Group A contained 14 tetrad-forming strains, and these strains were identified as Tetragenococcus halophilus by DNA similarity. Group B contained 30 rod-shaped bacteria, and they were further divided into four Subgroups, B1, B2, B3, and B4, and three ungrouped strains by phenotypic characteristics and DNA similarity. Subgroup B1 contained 16 strains, and these strains were identified as Lactobacillus acidipiscis by DNA similarity. Subgroup B2 included two strains, and the strains were identified as Lactobacillus farciminis by DNA similarity. Subgroup B3 contained five strains. The strains had meso-diaminopimelic acid in the cell wall, and were identified as Lactobacillus pentosus by DNA similarity. The strains tested produced DL-lactic acid from D-glucose. Subgroup B4 contained four strains. The strains had meso-diaminopimelic acid in the cell wall, and they were identified as Lactobacillus plantarum by DNA similarity. Two ungrouped strains were homofermentative, and one was heterofermentative. They showed a low degree of DNA similarity with the type strains tested, and were left unnamed. The distribution of lactic acid bacteria in soy sauce mash in Thailand is discussed. PMID:12469319

  3. Batch fermentations on synthetic mixed sugar and starch medium with amylolytic lactic acid bacteria

    DEFF Research Database (Denmark)

    Thomsen, Mette Hedegaard; Guyot, J.P.; Kiel, P.

    2007-01-01

    process. A number of amylolytic lactic acid bacteria have been identified, and in this work, six different strains were tested for their ability to produce alpha-amylase and to utilise all sugars with high lactic acid yield in a medium with a complex composition of free sugars (brown juice) and starch...... brown juice. Brown juice was shown to be an excellent medium for lactic acid fermentation. The aim of this study was to investigate the utilisation of brown juice in the production of polylactic acid, where wheat starch would be added to increase the lactic acid yield and, thus, the feasibility of the....... Lactobacillus plantarum A6 was the only strain that showed both a good lactic acid production and utilisation of starch in this medium. The growth rate of this strain was approximately 0.4 h(-1) and the lactic acid yield was 0.7....

  4. Influence of temperature on production of lactic acid from kitchen garbage

    Institute of Scientific and Technical Information of China (English)

    汪群慧; 徐忠; 孟令辉; 孙晓红; 王旭明

    2003-01-01

    The production of lactic acid from kitchen garbage, the precursor for production of biodegradableplastics is described in detail. The influence of temperature on the lactic acid concentration, sugar concentra-tion, and decrement of garbage were evaluated through experiments. Fermentation were carried out in an incu-bator at 5, 25, 37 and 50 ℃. The latic acid produced was maximum at initial pH 6.0 and 37 ℃ , i.e. 38 g/Lwith a yield of 0.23 g/gVS. It is concluded from the experimental results that temperature has quite a consider-able effect on the production of lactic acid; lactic acid concentration increases with temperature until 37 ℃ ,and production rate of lactic acid drops at 50 ℃; the optimal fermentation is 37 ℃. This study shows that pro-duction of lactic acid from kitchen garbage is feasible and reduction of garbage can be realized.

  5. Intermediality and the Child Performer

    Science.gov (United States)

    Budd, Natasha

    2016-01-01

    This report details examples of praxis in the creation and presentation of "Joy Fear and Poetry": an intermedial theatre performance in which children aged 7-12 years generated aesthetic gestures using a range of new media forms. The impetus for the work's development was a desire to make an intervention into habituated patterns of…

  6. Material Voices: Intermediality and Autism

    Science.gov (United States)

    Trimingham, Melissa; Shaughnessy, Nicola

    2016-01-01

    Autism continues to be regarded enigmatically; a community that is difficult to access due to perceived disruptions of interpersonal connectedness. Through detailed observations of two children participating in the Arts and Humanities Research Council funded project "Imagining Autism: Drama, Performance and Intermediality as Interventions for…

  7. Intermediate business programming with C++

    CERN Document Server

    Voils, Don

    2005-01-01

    Intermediate Business Programming with C++ 2005 offers a comprehensive approach to the topic with emphasis on the creation of object oriented programs for business and the use of data structures, this book deals with the writing of business programs using C++ from Microsoft Visual Studio .NET 2005.

  8. Reactivity of surface carbonaceous intermediates. Doctoral thesis

    Energy Technology Data Exchange (ETDEWEB)

    Koerts, T.

    1992-06-19

    The study has concentrated on two reactions both related with carbon-carbon bond formation on transition metal catalysts. The first concerns the influences of a vanadium promoter on the kinetics of elementary reaction steps upon synthesis gas conversion on a rhodium catalyst. The second is related to the general problem of initiating a carbon-carbon bond between two methane molecules. Both reactions occur via reactive C1 surface intermediates. These surface species were created from CO and CH4 respectively. Mainly transient kinetic techniques were used which were combined with some quantum chemical calculations. The influence of a vanadium promoter on the formation and intrinsic reactivity of CHx species adsorbed on rhodium catalysts, for hydrogenation, chaingrowth and CO insertion, has also been investigated. On rhodium catalysts a very reactive C1 intermediate was found to be formed from dissociative CO adsorption. The formation of the surface species was found to be enhanced by vanadium promotion, which lowers the activation energy for CO dissociation.

  9. TECHNOLOGICAL AND FUNCTIONAL PROPERTIES OF LACTIC ACID BACTERIA: THE IMPORTANCE OF THESE MICROORGANISMS FOR FOOD

    OpenAIRE

    Amanda de Souza Motta; Melina Da Silva Mesquita Gomes

    2015-01-01

    Eacters of coccus or rods Gram-positive, catalase negative, non-sporulating, which produce lactic acid as the major end product during the fermentation of carbohydrates. When applied on food, provides beneficial effects to consumers through its functional and technological properties. With this the present review article, explore the potential application of lactic acid bacteria in food. The following genera are considered the principal lactic acid bacteria: Aerococcus, Carnobacterium, Entero...

  10. Chitosan and lactic acid-grafted chitosan nanoparticles as carriers for prolonged drug delivery

    OpenAIRE

    Bhattarai, Narayan; Ramay, Hassna R; Chou, Shinn-Huey; Zhang, Miqin

    2006-01-01

    Nanoparticles of ~10 nm in diameter made with chitosan or lactic acid-grafted chitosan were developed for high drug loading and prolonged drug release. A drug encapsulation efficiency of 92% and a release rate of 28% from chitosan nanoparticles over a 4-week period were demonstrated with bovine serum protein. To further increase drug encapsulation, prolong drug release, and increase chitosan solubility in solution of neutral pH, chitosan was modified with lactic acid by grafting D,L-lactic ac...

  11. STUDY ON PROBIOTIC POTENTIAL AND LABORATORY SCALE PRODUCTION OF LACTIC ACID BACTERIA

    OpenAIRE

    Ambule A.H.; Timande S.P; Soni S.B

    2012-01-01

    Lactic acid bacteria were isolated from dairy food. They were identified on the basis of theirmorphological, cultural and biochemical characterastics.The cell free supernatant of lactic acid bacteria were ableto inhibit the growth ofE.coli,Klebsiella aerogens,Salmonella spp. , S.aureus, P.mirabilies and Ps .aeruginosa.The probiotic properties of isolate of lactic acid bacteria (LAB-VI) were investigated. The LAB-VI wassusceptible to antibiotics like ampicillin, gentamycin, ciprofloxacin, oflo...

  12. Fermentation of Prefermented and Extruded Rice Flour by Lactic Acid Bacteria from Sikhae

    DEFF Research Database (Denmark)

    Lee, C. H.; Min, K. C.; Souane, M.; Mathiasen, T. E.; Adler-Nissen, Jens; Chung, M. J.

    1992-01-01

    prefermentation of rice flour in solid-state with Bacillus laevolacticus and Saccharomyces cerevisiae, extrusion cooking and addition of soymilk as the substrate of lactic acid fermentation were tested. Extrusion cooking and prefermentation of rice increased the soluble solid and sugar contents before malt...... objectionable off-flavor. The HPLC analysis shoved that the lactic ferment of L. mesenteroides(sikhae) contained relatively small amount of lactic acid and malic acid which vas not detected in other microorganisms tested....

  13. Batch and Continuous Lactic Acid Production from Cassava by Streptococcus bovis

    OpenAIRE

    Fachrul Razi; S D Yuwono

    2006-01-01

    Process variables were optimized for the production of lactic acid from cassava by Streptococcus bovis for batch and continuous fermentations. In the batch fermentation, maximum yield 82.5% and maximum lactic acid productivity 2.43 was achieved at 39 oC, pH 5.5 with 50 g/l cassava concentration. In the continuous fermentation maximum productivity lactic acid 1.25 g/l.h was obtained at dilution rate 0.05 /h.

  14. Growth inhibition of Streptococcus mutans by cellular extracts of human intestinal lactic acid bacteria.

    OpenAIRE

    Ishihara, K; Miyakawa, H; Hasegawa, A.; Takazoe, I; Kawai, Y.

    1985-01-01

    The in vitro growth of Streptococcus mutans was completely inhibited by water-soluble extracts from cells of various intestinal lactic acid bacteria identified as Streptococcus faecium, Streptococcus equinus, Lactobacillus fermentum, and Lactobacillus salivarius. The growth inhibition was dependent on the concentrations of the extracts. In contrast, the extracts did not inhibit the growth of the major indigenous intestinal lactic acid bacteria isolated from humans. These lactic acid bacteria ...

  15. Anaerobic Conversion of Lactic Acid to Acetic Acid and 1,2-Propanediol by Lactobacillus buchneri

    OpenAIRE

    Oude Elferink, S.J.W.H.; Krooneman, J.; Gottschal, J.C.; Spoelstra, S F; FABER, F; Driehuis, F

    2001-01-01

    The degradation of lactic acid under anoxic conditions was studied in several strains of Lactobacillus buchneri and in close relatives such as Lactobacillus parabuchneri, Lactobacillus kefir, and Lactobacillus hilgardii. Of these lactobacilli, L. buchneri and L. parabuchneri were able to degrade lactic acid under anoxic conditions, without requiring an external electron acceptor. Each mole of lactic acid was converted into approximately 0.5 mol of acetic acid, 0.5 mol of 1,2-propanediol, and ...

  16. Silver/poly (lactic acid nanocomposites: preparation, characterization, and antibacterial activity

    Directory of Open Access Journals (Sweden)

    Kamyar Shameli

    2010-08-01

    Full Text Available Kamyar Shameli1, Mansor Bin Ahmad1, Wan Md Zin Wan Yunus1, Nor Azowa Ibrahim1, Russly Abdul Rahman2, Maryam Jokar2,3, Majid Darroudi41Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, Selangor, Malaysia; 2Department of Food Technology, Faculty of Food Science and Technology, Universiti Putra Malaysia, Selangor, Malaysia; 3Department of Food Technology, Islamic Azad University, Damghan Branch, Damghan, Iran; 4Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology (ITMA, Universiti Putra Malaysia, Selangor, MalaysiaAbstract: In this study, antibacterial characteristic of silver/poly (lactic acid nanocomposite (Ag/PLA-NC films was investigated, while silver nanoparticles (Ag-NPs were synthesized into biodegradable PLA via chemical reduction method in diphase solvent. Silver nitrate and sodium borohydride were respectively used as a silver precursor and reducing agent in the PLA, which acted as a polymeric matrix and stabilizer. Meanwhile, the properties of Ag/PLA-NCs were studied as a function of the Ag-NP weight percentages (8, 16, and 32 wt% respectively, in relation to the use of PLA. The morphology of the Ag/PLA-NC films and the distribution of the Ag-NPs were also characterized. The silver ions released from the Ag/PLA-NC films and their antibacterial activities were scrutinized. The antibacterial activities of the Ag/PLA-NC films were examined against Gram-negative bacteria (Escherichia coli and Vibrio parahaemolyticus and Gram-positive bacteria (Staphylococcus aureus by diffusion method using Muller–Hinton agar. The results indicated that Ag/PLA-NC films possessed a strong antibacterial activity with the increase in the percentage of Ag-NPs in the PLA. Thus, Ag/PLA-NC films can be used as an antibacterial scaffold for tissue engineering and medical application.Keywords: antibacterial activity, silver nanoparticles, biodegradable, poly (lactic acid, Muller–Hinton agar.

  17. L-lactic acid production by Aspergillus brasiliensis overexpressing the heterologous ldha gene from Rhizopus oryzae

    OpenAIRE

    Liaud, Nadège; Rosso, Marie-Noëlle; Fabre, Nicolas; Crapart, Sylvaine; Herpoël-Gimbert, Isabelle; Sigoillot, Jean-Claude; Raouche, Sana; Levasseur, Anthony

    2015-01-01

    International audience Background: Lactic acid is the building block of poly-lactic acid (PLA), a biopolymer that could be set to replace petroleum-based plastics. To make lactic acid production cost-effective, the production process should be carried out at low pH, in low-nutrient media, and with a low-cost carbon source. Yeasts have been engineered to produce high levels of lactic acid at low pH from glucose but not from carbohydrate polymers (e.g. cellulose, hemicellulose, starch). Aspe...

  18. Production of lactic acid from C6-polyols by alkaline hydrothermal reactions

    International Nuclear Information System (INIS)

    Production of lactic acid from C6-polyols (Mannitol) under alkaline hydrothermal conditions was investigated. Experiments were performed to examine the difference in the production of lactic acid between C6-polyols and C3-polyols (glycerine), as well as C6-aldoses (glucose). Results showed that the yield of lactic acid from C6-polyols was lower than that from both glycerine and glucose. It indicated that long chain polyols might follow a different reaction pathway from that of glycerine. Further investigation is needed to clarify the reaction mechanism and improve the relatively low lactic acid acid yield from C6-polyols.

  19. D-Lactic Acidosis: An Underrecognized Complication of Short Bowel Syndrome

    OpenAIRE

    N. Gurukripa Kowlgi; Lovely Chhabra

    2015-01-01

    D-lactic acidosis or D-lactate encephalopathy is a rare condition that occurs primarily in individuals who have a history of short bowel syndrome. The unabsorbed carbohydrates act as a substrate for colonic bacteria to form D-lactic acid among other organic acids. The acidic pH generated as a result of D-lactate production further propagates production of D-lactic acid, hence giving rise to a vicious cycle. D-lactic acid accumulation in the blood can cause neurologic symptoms such as delirium...

  20. Larval helminths in intermediate hosts

    DEFF Research Database (Denmark)

    Fredensborg, Brian Lund; Poulin, R

    2005-01-01

    transmission to their bird definitive host by predation. In experimental infections, we found an intensity-dependent establishment success, with a decrease in the success rate of cercariae developing into infective metacercariae with an increasing dose of cercariae applied to each amphipod. In natural......Density-dependent effects on parasite fitness have been documented from adult helminths in their definitive hosts. There have, however, been no studies on the cost of sharing an intermediate host with other parasites in terms of reduced adult parasite fecundity. Even if larval parasites suffer a...... reduction in size, caused by crowding, virtually nothing is known about longer-lasting effects after transmission to the definitive host. This study is the first to use in vitro cultivation with feeding of adult trematodes to investigate how numbers of parasites in the intermediate host affect the size and...

  1. Financial Intermediation with Risk Aversion

    OpenAIRE

    Hellwig, Martin

    1998-01-01

    The paper extends Diamond's (1984) analysis of financial intermediation to allow for risk aversion of the intermediary. It shows that, as in the case of risk neutrality, the agency costs of external funds provided to an intermediary are relatively small if the intermediary is financing many entrepreneurs with stochastically independent returns. Even though the intermediary is adding rather than subdividing risks, the underlying large-numbers argument is not invalidated by the presence of risk...

  2. The genomic analysis of lactic acidosis and acidosis response in human cancers.

    Directory of Open Access Journals (Sweden)

    Julia Ling-Yu Chen

    2008-12-01

    Full Text Available The tumor microenvironment has a significant impact on tumor development. Two important determinants in this environment are hypoxia and lactic acidosis. Although lactic acidosis has long been recognized as an important factor in cancer, relatively little is known about how cells respond to lactic acidosis and how that response relates to cancer phenotypes. We develop genome-scale gene expression studies to dissect transcriptional responses of primary human mammary epithelial cells to lactic acidosis and hypoxia in vitro and to explore how they are linked to clinical tumor phenotypes in vivo. The resulting experimental signatures of responses to lactic acidosis and hypoxia are evaluated in a heterogeneous set of breast cancer datasets. A strong lactic acidosis response signature identifies a subgroup of low-risk breast cancer patients having distinct metabolic profiles suggestive of a preference for aerobic respiration. The association of lactic acidosis response with good survival outcomes may relate to the role of lactic acidosis in directing energy generation toward aerobic respiration and utilization of other energy sources via inhibition of glycolysis. This "inhibition of glycolysis" phenotype in tumors is likely caused by the repression of glycolysis gene expression and Akt inhibition. Our study presents a genomic evaluation of the prognostic information of a lactic acidosis response independent of the hypoxic response. Our results identify causal roles of lactic acidosis in metabolic reprogramming, and the direct functional consequence of lactic acidosis pathway activity on cellular responses and tumor development. The study also demonstrates the utility of genomic analysis that maps expression-based findings from in vitro experiments to human samples to assess links to in vivo clinical phenotypes.

  3. Branching of keratin intermediate filaments.

    Science.gov (United States)

    Nafeey, Soufi; Martin, Ines; Felder, Tatiana; Walther, Paul; Felder, Edward

    2016-06-01

    Keratin intermediate filaments (IFs) are crucial to maintain mechanical stability in epithelial cells. Since little is known about the network architecture that provides this stiffness and especially about branching properties of filaments, we addressed this question with different electron microscopic (EM) methods. Using EM tomography of high pressure frozen keratinocytes, we investigated the course of several filaments in a branching of a filament bundle. Moreover we found several putative bifurcations in individual filaments. To verify our observation we also visualized the keratin network in detergent extracted keratinocytes with scanning EM. Here bifurcations of individual filaments could unambiguously be identified additionally to bundle branchings. Interestingly, identical filament bifurcations were also found in purified keratin 8/18 filaments expressed in Escherichia coli which were reassembled in vitro. This excludes that an accessory protein contributes to the branch formation. Measurements of the filament cross sectional areas showed various ratios between the three bifurcation arms. This demonstrates that intermediate filament furcation is very different from actin furcation where an entire new filament is attached to an existing filament. Instead, the architecture of intermediate filament bifurcations is less predetermined and hence consistent with the general concept of IF formation. PMID:27039023

  4. Interactive Chemical Reactivity Exploration

    OpenAIRE

    Haag, Moritz P.; Vaucher, Alain C.; Bosson, Mael; Redon, Stephane; Reiher, Markus

    2014-01-01

    Elucidating chemical reactivity in complex molecular assemblies of a few hundred atoms is, despite the remarkable progress in quantum chemistry, still a major challenge. Black-box search methods to find intermediates and transition-state structures might fail in such situations because of the high-dimensionality of the potential energy surface. Here, we propose the concept of interactive chemical reactivity exploration to effectively introduce the chemist's intuition into the search process. ...

  5. Optimization of lactic ferment with quinoa flour as bio-preservative alternative for packed bread.

    Science.gov (United States)

    Dallagnol, Andrea Micaela; Pescuma, Micaela; Rollán, Graciela; Torino, María Inés; de Valdez, Graciela Font

    2015-05-01

    The consumers' demand for food with high nutritional quality and free of chemical additives increases the need to look for new products and preservation strategies. Quinoa (Chenopodium quinoa) is an Andean pseudocereal highly appreciated because of its nutritional properties. Moreover, it is an optimal substrate for growing and production of improved amounts of antifungal compounds by Lactobacillus plantarum CRL 778. The aim of this work was to optimize a lactic ferment for packaged breads with improved nutritional value and prolonged shelf life by applying a statistical experimental design model. The addition of 30 % quinoa to the wheat semiliquid ferment (QWF) could highly improve the amino acids release (4.3 g/L) during fermentation. Moreover, this quinoa proportion was sufficient to obtain the same concentration of the antifungal compounds, phenyllactic and hydroxiphenyllactic acids (PLA and OH-PLA) as with 100 % quinoa (ca. 36 and 51 mg/L, respectively). Statistical model analysis showed that citrate and skimmed milk enhanced significantly all evaluated parameters specially PLA (ca. 71 mg/L), HO-PLA (ca. 75 mg/L), and lactate (27 g/L) with a p value <0.005. The synergic effects of higher antifungal compounds production, acid release, and pH decrease allowed lowering the amount (about 50 %) of the chemical preservative calcium propionate commonly added to bread. Moreover, these breads show increased shelf life. PMID:25758954

  6. Effects of gas atmospheres on poly(lactic acid) film in acrylic acid plasma treatment

    International Nuclear Information System (INIS)

    Plasma polymerized acrylic acid (AA) coatings were deposited on poly(lactic acid) (PLA) films in various gas atmospheres during the pre-treatment of PLA and the deposition of AA, respectively. Therefore, this work was twofold: the argon pretreated PLA films followed by a deposition in argon were investigated against the mixture of argon and oxygen pretreated ones under the same deposition conditions; the plasma deposition of AA operating in different atmospheres (argon, oxygen and nitrogen) was employed to modify the pretreated PLA in oxygen. Chemical and physical changes on the plasma-treated surfaces were examined using contact angle, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM) and attenuated total reflection infrared (ATR-FTIR) analysis. The results showed that the discharge gas can have a significant influence on the chemical composition of the PLA surfaces: oxygen plasmas introduced oxygen-containing groups in company with surface etching in pretreatment and deposition, while argon discharges was able to achieve much better hydrophilic behavior and high retention ratio of poly(acrylic acid) (PAA) coating before and after washing in water.

  7. Effects of gas atmospheres on poly(lactic acid) film in acrylic acid plasma treatment

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yun, E-mail: yun.zhaotju@yahoo.com [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Turin (Italy); Fina, Alberto [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino – sede di Alessandria, V. T. Michel 5, 15121 Alessandria (Italy); Venturello, Alberto; Geobaldo, Francesco [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Turin (Italy)

    2013-10-15

    Plasma polymerized acrylic acid (AA) coatings were deposited on poly(lactic acid) (PLA) films in various gas atmospheres during the pre-treatment of PLA and the deposition of AA, respectively. Therefore, this work was twofold: the argon pretreated PLA films followed by a deposition in argon were investigated against the mixture of argon and oxygen pretreated ones under the same deposition conditions; the plasma deposition of AA operating in different atmospheres (argon, oxygen and nitrogen) was employed to modify the pretreated PLA in oxygen. Chemical and physical changes on the plasma-treated surfaces were examined using contact angle, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM) and attenuated total reflection infrared (ATR-FTIR) analysis. The results showed that the discharge gas can have a significant influence on the chemical composition of the PLA surfaces: oxygen plasmas introduced oxygen-containing groups in company with surface etching in pretreatment and deposition, while argon discharges was able to achieve much better hydrophilic behavior and high retention ratio of poly(acrylic acid) (PAA) coating before and after washing in water.

  8. Lactic acid as a decontaminant in slaughter and processing procedures.

    Science.gov (United States)

    Snijders, J M; van Logtestijn, J G; Mossel, D A; Smulders, F J

    1985-10-01

    An attempt was made to interrelate the data obtained in experiments conducted by our Department along beef, veal and pig slaughter lines, using lactic acid (LA) for the decontamination of carcasses, cold and hot boned primal cuts, slaughter byproducts, and butcher's knives. First and foremost it was observed, that provided Good Manufacturing Practices are strictly followed, the microbial load of carcass surfaces will be substantially reduced. LA-decontamination may result in an additional reduction. Since in the early post-mortem period bacteria are not yet attached to the meat surface, LA-decontamination should preferably be applied to the hot carcass. It was demonstrated that, dependent on mode and duration of application, LA sprays not exceeding 1% v/v (beef), 1.25% v/v (veal) and 1.5% v/v (pork) resulted in acceptable carcass colour scores. Blood spots, which are particularly prone to discolouration by lactic acid application, should be removed at an early post-mortem stage e.g. by strong showering. The difference in surface pH between LA-treated and control carcasses disappeared within 72 hours post-mortem. Veal longissimus chops treated with LA solutions up to 2% v/v were not identified by a consumer taste panel as significantly different from controls. The 'immediate' bactericidal effect of LA-decontamination for beef, veal and pig carcasses, as well as for pig liver and veal brain, amounted to approximately 1.5 log cycles for the aerobic colony counts, strongly dependent on substrate and conditions of decontamination. In addition, a 'delayed' bacteriostatic effect was observed during storage, which is probably the result of a prolonged lag phase of acid-injured micro-organisms surviving lactic acid decontamination.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:4071948

  9. Evaluation of different lactic acid bacterial strains for probiotic characteristics

    Directory of Open Access Journals (Sweden)

    B. Srinu,

    2013-08-01

    Full Text Available Objective: The objective of the present study was to collect different Lactic acid bacterial strains from culture collection centers and screen their functional probiotic characteristics such as acid tolerance, bile tolerance, antibacterial activity and antibiotic sensitivity for their commercial use. Materials and Methods: Acid and bile tolerence of selected LAB(Lactic acid bacteria was determined. The antibiotic resistance of Lactobacillus species was assessed using different antibiotic discs on de Mann Rogosa Sharpe broth (MRS agar plates seeded with the test probiotic organism. The antibacterial activity of LAB was assessed by using well diffusion method.Results: Among the six probiotic strains tested, all showed good survivability at high bile salt concentration (0.3 to 2.0 % oxgall and good growth at a low pH of 1.5 to 3.5. These probiotic species showed good survival abilities in acidic pH of 2.0 to 3.5 except Lactobacillus delbrueckii subspp. bulgaricus 281 which did not grown at pH of 2.0. Lactobacillus fermentum 141 was able to grow even at pH of 1.5 also. Among the six lactic acid species, Lactobacillus fermentum 141 (except Tetracycline, Lactobacillus delbrueckii subspp. Bulgaricus 281 except (Cefpodoxime and all other LAB were resistant to all the antibiotics tested (Ampicillin, Nalidixic acid , Ciprofloxacin ,Co-Trimoxazole, Gentamicin and Cefpodoxime. All these probiotic organisms were screened for their in vitro inhibition ability against pathogenic microorganisms namely, E.coli ATCC (American type culture collection centre, Pseudomonas aeruginosa, Salmonella paratyphi, Staphylococcus aureus. Lactobacillus delbrueckii subspp. bulgaricus 281, Lactobacillus casei 297 and Lactobacillus fermentum 141 inhibited the growth of all the pathogenic bacteria used in the study. Conclusion: The study indicated Lactobacillus fermentum 141 and Lactobacillus casei 297 as potential functional probiotics for future in vivo studies for

  10. Utilization of Molasses Sugar for Lactic Acid Production by Lactobacillus delbrueckii subsp. delbrueckii Mutant Uc-3 in Batch Fermentation▿

    OpenAIRE

    Dumbrepatil, Arti; Adsul, Mukund; Chaudhari, Shivani; Khire, Jayant; Gokhale, Digambar

    2007-01-01

    Efficient lactic acid production from cane sugar molasses by Lactobacillus delbrueckii mutant Uc-3 in batch fermentation process is demonstrated. Lactic acid fermentation using molasses was not significantly affected by yeast extract concentrations. The final lactic acid concentration increased with increases of molasses sugar concentrations up to 190 g/liter. The maximum lactic acid concentration of 166 g/liter was obtained at a molasses sugar concentration of 190 g/liter with a productivity...

  11. Impact of Lactic Acid on Cell Proliferation and Free Radical Induced Cell Death in Monolayer Cultures of Neural Precursor Cells

    OpenAIRE

    Lampe, Kyle J.; Namba, Rachael M.; Silverman, Tyler R.; Bjugstad, Kimberly B.; Mahoney, Melissa J.

    2009-01-01

    Biomaterials prepared from polyesters of lactic acid and glycolic acid, or a mixture of the two, degrade in the presence of water into the naturally occurring metabolites, lactic acid and glycolic acid. While the lactic acid degradation product that is released from biomaterials is well-tolerated by the body, lactic acid can influence the metabolic function of cells; it can serve as an energy substrate for cells, and has been shown to have antioxidant properties. Neural precursor cells, a cel...

  12. Phytase-active lactic acid bacteria from sourdoughs

    DEFF Research Database (Denmark)

    Nuobariene, Lina; Cizeikiene, Dalia; Gradzeviciute, Egle;

    2015-01-01

    Whole-grain foods play an important role in human diet as they are relatively rich in minerals, however, the absorption of those minerals in human gut can be very low due to high content of the mineral binding phytate. Therefore, the object of this study was to identify phytase-active lactic acid...... bacteria (LAB) which could be used as a starter to increase mineral bioavailability in whole-meal bread. Hence, LAB isolates were isolated from Lithuanian sourdoughs, tested for phytase activity, and phytase active isolates were identified. Studies of phytase activity of the isolates were carried out at...

  13. Kinetics of Demineralization of Shrimp Shell Using Lactic Acid

    Directory of Open Access Journals (Sweden)

    Alewo Opuada AMEH

    2014-02-01

    Full Text Available Shrimp exoskeleton was demineralized using lactic acid and the kinetics of the demineralisation was studied. The residual concentration of calcium after acid treatment was used as a measure of the degree of demineralisation. Kinetic data was obtained using five acid concentrations (0.2, 0.4, 0.6, 0.8 and 1M and the obtained kinetic data was fitted to the shrinking core model. For all concentrations, the best predictive model was determined to be ash layer diffusion controlled mechanism.

  14. Occurrence and role of lactic acid bacteria in seafood products

    OpenAIRE

    Leroi, Francoise

    2010-01-01

    Lactic acid bacteria (LAB) in fish flesh has long been disregarded because the high post-mortem pH, the low percentage of sugars, the high content of low molecular weight nitrogenous molecules and the low temperature of temperate waters favor the rapid growth of pH-sensitive psychrotolerant marine Gram-negative bacteria like Pseudomonas, Shewanella and Photobacterium. In seafood packed in both vacuum (VP) and modified atmosphere (MAP) packaging commonly CO2 enriched, the growth of the Gram-ne...

  15. Metabolic engineering of lactic acid bacteria for the production of nutraceuticals

    NARCIS (Netherlands)

    Hugenholtz, J.; Sybesma, W.; Groot, M.N.; Wisselink, W.; Ladero, V.; Burgess, K.; Sinderen, van D.; Piard, J.C.; Eggink, G.; Smid, E.J.; Savoy, G.; Sesma, F.; Jansen, T.; Hols, P.; Kleerebezem, M.

    2002-01-01

    Lactic acid bacteria display a relatively simple and well-described metabolism where the sugar source is converted mainly to lactic acid. Here we will shortly describe metabolic engineering strategies on the level of sugar metabolism, that lead to either the efficient re-routing of the lactococcal s

  16. Reality of severe metformin-induced lactic acidosis in the absence of chronic renal impairment.

    NARCIS (Netherlands)

    Bruijstens, L.A.; Luin, M. van; Buscher-Jungerhans, P.M.; Bosch, F.H.

    2008-01-01

    BACKGROUND: Lactic acidosis in metformin use is a widely recognised but rare side effect. Case reports usually describe elderly patients with conditions which in themselves can cause lactic acidosis or with known contraindications to metformin. We present cases of an elderly woman, a younger woman a

  17. SLUG FLOW CAPILLARY MICROREACTORS FOR LACTIC ACID EXTRACTION: EXPERIMENTAL STUDY AND MASS TRANSFER MODELLING

    NARCIS (Netherlands)

    Susanti, Susanti; Winkelman, Jozef; Schuur, Boelo; Heeres, Hero; Yue, Jun

    2015-01-01

    Lactic acid is an important commercial product and has been widely used for manufacturing biodegradable polymer. Current method of lactic acid isolation from fermentation broths is energy intensive and leads to the formation of large amounts of salts. Reactive liquid-liquid extraction has been repor

  18. PREPARATION OF POLY (LACTIC ACID) THROUGH THIONYL CHLORIDE ACTIVATED POLYCONDENSATION

    Institute of Scientific and Technical Information of China (English)

    WANGZheng; YAOKangde; 等

    2000-01-01

    A two-step process was used to synthesize the high molecular weight poly (lactic acid) using thionyl chloride as an activator for the polycondensation of prepolymer of lactic acid.The products were characterized by GPC,DSC and 1H-NMR.Poly(L-lactic acid)(PLLA) with molecular weight Mw:32875 was obtained when thionyl chloride was used.while low molecular weight PLLA MW:7350 was yielded without thionyl chloride.Effects of the concentration of thionyl chloride,polymerization time and bases on the molecular weight of poly(lactic acid) were investigated.In DSC scans the glass transition temperatures(Tg)of the resulting polymers varied from 25.3 to 57.6℃.and the Tg of poly(L-lactic acid)was higher than that of poly (D,L0lactic acid)(PDLLA).The melting points of poly(L-lactic acid)and poly (D,L-lactic acid) could not be found unless the polymers were obtained by thionyl chloride activator.

  19. Materials for Intermediate-Temperature Solid-Oxide Fuel Cells

    Science.gov (United States)

    Kilner, John A.; Burriel, Mónica

    2014-07-01

    Solid-oxide fuel cells are devices for the efficient conversion of chemical energy to electrical energy and heat. Research efforts are currently addressed toward the optimization of cells operating at temperatures in the region of 600°C, known as intermediate-temperature solid-oxide fuel cells, for which materials requirements are very stringent. In addition to the requirements of mechanical and chemical compatibility, the materials must show a high degree of oxide ion mobility and electrochemical activity at this low temperature. Here we mainly examine the criteria for the development of two key components of intermediate-temperature solid-oxide fuel cells: the electrolyte and the cathode. We limit the discussion to novel approaches to materials optimization and focus on the fluorite oxide for electrolytes, principally those based on ceria and zirconia, and on perovskites and perovskite-related families in the case of cathodes.

  20. VHTR engineering design study: intermediate heat exchanger program. Final report

    International Nuclear Information System (INIS)

    The work reported is the result of a follow-on program to earlier Very High Temperature Reactor (VHTR) studies. The primary use of the VHTR is to provide heat for various industrial processes, such as hydrocarbon reforming and coal gasification. For many processes the use of an intermediate heat transfer barrier between the reactor coolant and the process is desirable; for some processes it is mandatory. Various intermediate heat exchanger (IHX) concepts for the VHTR were investigated with respect to safety, cost, and engineering design considerations. The reference processes chosen were steam-hydrocarbon reforming, with emphasis on the chemical heat pipe, and steam gasification of coal. The study investigates the critically important area of heat transfer between the reactor coolant, helium, and the various chemical processes

  1. VHTR engineering design study: intermediate heat exchanger program. Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1976-11-01

    The work reported is the result of a follow-on program to earlier Very High Temperature Reactor (VHTR) studies. The primary use of the VHTR is to provide heat for various industrial processes, such as hydrocarbon reforming and coal gasification. For many processes the use of an intermediate heat transfer barrier between the reactor coolant and the process is desirable; for some processes it is mandatory. Various intermediate heat exchanger (IHX) concepts for the VHTR were investigated with respect to safety, cost, and engineering design considerations. The reference processes chosen were steam-hydrocarbon reforming, with emphasis on the chemical heat pipe, and steam gasification of coal. The study investigates the critically important area of heat transfer between the reactor coolant, helium, and the various chemical processes.

  2. Role of Intermediate Filaments in Vesicular Traffic

    Directory of Open Access Journals (Sweden)

    Azzurra Margiotta

    2016-04-01

    Full Text Available Intermediate filaments are an important component of the cellular cytoskeleton. The first established role attributed to intermediate filaments was the mechanical support to cells. However, it is now clear that intermediate filaments have many different roles affecting a variety of other biological functions, such as the organization of microtubules and microfilaments, the regulation of nuclear structure and activity, the control of cell cycle and the regulation of signal transduction pathways. Furthermore, a number of intermediate filament proteins have been involved in the acquisition of tumorigenic properties. Over the last years, a strong involvement of intermediate filament proteins in the regulation of several aspects of intracellular trafficking has strongly emerged. Here, we review the functions of intermediate filaments proteins focusing mainly on the recent knowledge gained from the discovery that intermediate filaments associate with key proteins of the vesicular membrane transport machinery. In particular, we analyze the current understanding of the contribution of intermediate filaments to the endocytic pathway.

  3. Preparation of Cylinder-Shaped Porous Sponges of Poly(L-lactic acid), Poly(DL-lactic-co-glycolic acid), and Poly(ε-caprolactone)

    OpenAIRE

    2014-01-01

    Design of mechanical skeletons of biodegradable synthetic polymers such as poly(L-lactic acid) (PLLA), poly(DL-lactic-co-glycolic acid) (PLGA), and poly( ε -caprolactone) (PCL) is important in the construction of the hybrid scaffolds of biodegradable synthetic polymers and naturally derived polymers such as collagen. In this study, cylinder-shaped PLLA, PLGA, and PCL sponges were prepared by the porogen leaching method using a cylinder model. The effects of polymer type, polymer fraction, cyl...

  4. SOLID AND LIQUID PINEAPPLE WASTE UTILIZATION FOR LACTIC ACID FERMENTATION USING Lactobacillus delbrueckii

    Directory of Open Access Journals (Sweden)

    Abdullah Abdullah

    2012-01-01

    Full Text Available The liquid and solid  pineapple wastes contain mainly sucrose, glucose, fructose and other nutrients. It therefore can potentially be used as carbon source for fermentation to produce organic acid. Recently, lactic acid has been considered to be an important raw material for production of biodegradable lactate polymer. The experiments were  carried out in batch fermentation using  the  liquid and solid pineapple wastes to produce lactic acid. The anaerobic fermentation of lactic acid were performed at 40 oC, pH 6, 5% inocolum and  50 rpm. Initially  results show that the liquid pineapple waste by  using Lactobacillus delbrueckii can be used as carbon source  for lactic acid fermentation. The production of lactic acid  are found to be 79 % yield, while only  56% yield was produced by using solid waste. 

  5. THE FUNCTIONS OF FINANCIAL INTERMEDIATION - A SURVEY

    OpenAIRE

    Andries Marius Alin

    2009-01-01

    Traditional theories of intermediation are based on transaction costs and asymmetric information. In recent decades although transaction costs and asymmetric information have declined, intermediation has increased. New markets for financial futures and options are mainly markets for intermediaries rather than individuals or firms. In this paper we survey the last theoretical and empirical research on financial intermediation and functions of financial intermediation. We discuss the functions ...

  6. How Should Financial Intermediation Services be Taxed?

    OpenAIRE

    Lockwood, Ben

    2010-01-01

    This paper considers the optimal taxation of two types of financial intermediation services (savings intermediation, and payment services) in a dynamic general equilibrium setting, when the government can also use consumption and income taxes. When payment services are used in strict proportion to final consumption, and the cost of intermediation services is the same across firms, the optimal taxes on financial intermediation are generally indeterminate. But, when firms differ in the cost of ...

  7. ESL intermediate/advanced writing

    CERN Document Server

    Munoz Page, Mary Ellen; Jaskiewicz, Mary

    2011-01-01

    Master ESL (English as a Second Language) Writing with the study guide designed for non-native speakers of English. Skill-building lessons relevant to today's topics help ESL students write complete sentences, paragraphs, and even multi-paragraph essays. It's perfect for classroom use or self-guided writing preparation.DETAILS- Intermediate drills for improving skills with parallel structure, mood, correct shifting errors & dangling participles- Advanced essay drills focusing on narrative, descriptive, process, reaction, comparison and contrast- Superb preparation for students taking the TOEFL

  8. The effects of fermentation and adsorption using lactic acid bacteria culture broth on the feed quality of rice straw

    Institute of Scientific and Technical Information of China (English)

    LIU Jing-jing; LIU Xiao-ping; REN Ji-wei; ZHAO Hong-yan; YUAN Xu-feng; WANG Xiao-fen; Abdelfattah Z M Salem; CUI Zong-jun

    2015-01-01

    To improve the nutritional value and the palatability of air-dried rice straw, culture broth of the lactic acid bacteria community SFC-2 was used to examine the effects of two different treatments, fermentation and adsorption. Air-dried and chopped rice straw was treated with either fermentation for 30 d after adding 1.5 L nutrient solution (50 mL inocula L–1, 1.2×1012 CFU mL–1 inocula) kg–1 straw dry matter, or spraying a large amount of culture broth (1.5 L kg–1 straw dry matter, 1.5×1011 CFU mL–1 culture broth) on the straw and al owing it to adsorb for 30 min. The feed quality and aerobic stability of the resulting forage were examined. Both treatments improved the feed quality of rice straw, and adsorption was better than fermen-tation for preserving nutrients and improving digestibility, as evidenced by higher dry matter (DM) and crude protein (CP) concentrations, lower neutral detergent ifber (NDF), acid detergent ifber (ADF) and NH3-N concentrations, as wel as higher lactic acid production and in vitro digestibility of DM (IVDMD). The aerobic stability of the adsorbed straw and the fermented straw was 392 and 480 h, respectively. After being exposed to air, chemical components and microbial community of the fermented straw were more stable than the adsorbed straw.

  9. Two-Component Regulatory Systems – implication in the quorum sensing mechanisms and bacteriocin production in lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Lia–Mara Ditu

    2014-08-01

    Full Text Available For lactic acid bacteria, the mechanisms of quorum sensing and response are mediated by peptides or pheromones that interfere with the synthesis of antimicrobial peptides (AMP called bacteriocins, when these molecules reach a certain critical level of concentration. Generally, the synthesis and activity of pheromones is adjusted by means of a two-component regulatory system. The observation that some microorganisms, in particular lactic acid bacteria, produce bacteriocins according to the cell density, has led to the discovery of the involvement of QS mechanisms in the synthesis of these peptides. Bacteriocins synthesis is inducible, the process requiring the extracellular accumulation of peptides that functions as chemical messengers activators of bacteriocins synthesis. This minireview presents the molecular architecture and functions of two-component regulatory systems and ABC transporters implicated in the synthesis and secretion of nisin, one of the most studied bacteriocin. The elucidation of the intimate mechanisms of bacteriocins synthesis is equally of biotechnological and medical importance, opening interesting perspectives for the development of improved technologies for the production of bacteriocins with good yields, and also, for increasing the beneficial anti-infective roles of probiotic bacteria when administered in vivo.

  10. Analysis of Poly(Lactic-co-Glycolic Acid/Poly(Isoprene Polymeric Blend for application as biomaterial

    Directory of Open Access Journals (Sweden)

    Douglas Ramos Marques

    2013-01-01

    Full Text Available The application of renewable raw materials encourages research in the biopolymers area. The Poly(Lactic-co-Glycolic Acid/Poly(Isoprene (PLGA/IR blend combines biocompatibility for application in the health field with excellent mechanical properties. The blend was obtained by solubilization of polymers in organic solvents. To investigate the polymer thermochemical properties, FTIR and DSC were applied. To investigate the composition's influence over polymer mechanical properties, tensile and hardness test were applied. To analyze the blends response in the cell environment, a stent was produced by injection molding process, and Cell Viability Test and Previous Implantability were used. The Infrared spectra show that chemical composition is related only with polymers proportion in the blend. The calorimetry shows a partial miscibility in the blend. The tensile test shows that adding Poly(Isoprene to Poly(Lactic-co-Glycolic Acid induced a relevant reduction in the Young modulus, tensile stress and tenacity of the material, which was altered from the fragile raw PLGA to a ductile material. The composition did not affect the blend hardness. The cell viability test shows that the blend has potential application as biomaterial, while the first results of implantability indicate that the polymeric stent kept its original position and caused low fibrosis.

  11. Effect of Different Storage Period on Lactic Acid Bacterias from Goji Yogurt and Goji Yogurt with Honey

    Directory of Open Access Journals (Sweden)

    Ancuta M. Rotar

    2014-05-01

    Full Text Available Lactic acid bacterias (LAB: Streptococcus thermophilus-ST, Lactobacillus bulgaricus-LB are well known in the food technology area for their ability to produce lactic acid (LA from carbohydrates throught fermentation. In case of goji yogurt the interaction between the two species of LAB has influence on the fermentation period and LA quantity. LAB’s are widely used in the food industry because their growth in the dairy products lowers the carbohydrate content, they can also drop the pH values under 4.0, values were common pathogens are inhibited, and because of all these properties they are capable to prolong the shelf life. The present study aims to observe the evolution of LAB’s – ST and LB, from goji yogurt (7% (A and goji yogurt (7% with honey (B during the shelf life in corelation with other physico-chemical properties such as sugar content, fat content and dry matter. The samples for the evaluation were taken in the first day of storage, at the middle of storage period and in the last day of storage.

  12. Fermentation Quality and in Vitro Nutrient Digestibility of Fresh Rice Straw-Based Silage Treated with Lactic Acid Bacteria

    Directory of Open Access Journals (Sweden)

    B. Santoso

    2014-08-01

    Full Text Available The aim of the experiment was to evaluate fermentation characteristics and in vitro nutrient digestibility of fresh rice straw-based silage ensiled with addition of epiphytic lactic acid bacteria (LAB inoculant. The experiment was arranged in a completely randomized design, with 2 × 2 factorial arrangement of treatments. The first factor was the ratio of fresh rice straw (FRS, tofu waste (TW and cassava waste (CW consisted of two levels i.e., 40 : 20 : 40 and 40 : 25 : 35, on dry matter (DM basis. The second factor was the level of LAB inoculant with two levels ie., 0 and 20 mL/kg FM. The treatments were (A FRS + TW + CW with the ratio of 40 : 20 : 40, without LAB inoculant; (B FRS + TW + CW with the ratio of 40 : 20 : 40 + LAB inoculant; (C FRS + TW + CW with the ratio of 40 : 25 : 35, without LAB inoculant; (D FRS + TW + CW with ratio of 40 : 25 : 35 + LAB inoculant. Results showed that addition of LAB inoculant in silage increased lactic acid concentration (P0.05 on chemical composition, fermentation quality of silage and in vitro digestibility. It was concluded that mixture silage with ratio of 40 : 20 : 40 with the addition of LAB inoculant had the best fermentation quality and nutrient digestibility than other silages.

  13. Probiotic properties of endemic strains of lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Flora N. Tkhruni

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Charernjiratrakul, W.

    2007-07-01

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

  15. POTENTIAL OF CEREALS AND PSEUDOCEREALS FOR LACTIC ACID FERMENTATIONS

    Directory of Open Access Journals (Sweden)

    Ľubomír Valík

    2011-04-01

    Full Text Available Cereals and pseudocereals play a significant role in human nutrition. They are source of specific carbohydrates, proteins, lipids, fibre and wide spectrum of vitamins and minerals. Moreover, pseudocereals have a higher content of essential amino acids, e.g. lysine and tryptophan. Cereals and pseudocereals may also contain some antinutrition factors, such as phytic acid, polyphenols, trypsin inhibitors and inhibitors of α-amylase. These are responsible for reducing of protein and carbohydrate digestibility and decreasing accessibility of minerals due to complex formation. This review assesses the applications of cereals and pseudocereals in fermentation technology including the effects of lactic acid bacteria on nutrition, sensory quality and shelf-life. This work is focusing also on fermentation process of cereal matrice leading in degradation of antinutritional factors increase of nutritional value and availability of minerals, proteins and carbohydrates. Lactic acid bacteria produce many aromatic compounds that are beneficial to organoleptic atributes of the products. However, a few questions have been not answered in experiments, yet. For eample, is there any space for evaluation of their suitability to act as carriers of probiotics? Could such the attempts lead in development some special formulae suitable for consumers with food allergies or deficiencies?doi:10.5219/127

  16. Simultaneous production of l-lactic acid with high optical activity and a soil amendment with food waste that demonstrates plant growth promoting activity.

    Science.gov (United States)

    Kitpreechavanich, Vichien; Hayami, Arisa; Talek, Anfal; Chin, Clament Fui Seung; Tashiro, Yukihiro; Sakai, Kenji

    2016-07-01

    A unique method to produce highly optically-active l-lactic acid and soil amendments that promote plant growth from food waste was proposed. Three Bacillus strains Bacillus subtilis KBKU21, B. subtilis N3-9 and Bacillus coagulans T27, were used. Strain KBKU21 accumulated 36.9 g/L l-lactic acid with 95.7% optical activity and 98.2% l-lactic acid selectivity when fermented at 43°C for 84 h in a model kitchen refuse (MKR) medium. Residual precipitate fraction (anaerobically-fermented MKR (AFM) compost) analysis revealed 4.60%, 0.70% and 0.75% of nitrogen (as N), phosphorous (as P2O5), and potassium (as K2O), respectively. Additionally, the carbon to nitrogen ratio decreased from 13.3 to 10.6. AFM compost with KBKU21 promoted plant growth parameters, including leaf length, plant height and fresh weight of Brassica rapa (Komatsuna), than that by chemical fertilizers or commercial compost. The concept provides an incentive for the complete recycling of food waste, contributing towards a sustainable production system. PMID:26819060

  17. Carbon-13 kinetic isotope effect and its temperature dependence in the decarboxylation of lactic acid of natural isotopic composition with aqueous sulphuric acid

    International Nuclear Information System (INIS)

    Carbon-13 kinetic isotope effect in the decarboxylation of lactic acid of natural isotopic composition in sulphuric acid diluted with water in M(H2O)/M(H2SO4) molar ratio equal to 2.2 has been studied in the temperature range 80-130 C and found to be normal. The absolute values and the temperature dependence of the experimental 13C-K.I.E. are in agreement with the absolute values and the temperature dependence of the theoretical 13C-K.I.E. calculated under the assumption that one frequency corresponding to the carbon-oxygen bound broken in the decarboxylation reaction is lost in the course of activation of lactic acid molecules. The chemical side reactions leading to the abnormal temperature dependence of the carbon-13 and carbon-14 isotope fractionation, observed in the course of decarboxylation of lactic acid in concentrated sulphuric acid, have been suggested. (author). 11 refs, 1 fig., 1 tab

  18. Use of surfactants in enzymatic hydrolysis of rice straw and lactic acid production from rice straw by simultaneous saccharification and fermentation

    Directory of Open Access Journals (Sweden)

    Shichun Peng

    2007-01-01

    Full Text Available Rice straw (RS is one of the most abundant lignocellulosic waste by-products worldwide and provides an alternative substrate to produce useful chemicals such as bioethanol and lactic acid. However, higher enzyme loadings are needed to obtain a higher product yield, which makes the large-scale utilization economically difficult. The presence of non-ionic surfactants and poly(ethylene glycol (PEG during the enzymatic hydrolysis of lignocellulosics has been found to increase the conversion of cellulose into fermentable sugars. We have found that adding 0.2g g-1 substrate of polyoxyethylene(20 sorbitan monooleate (PSM or high-mass PEG increased the sugar yield by 22% and 12%, respectively, when enzyme loading was at 10FPU g-1 for 24h. PSM behaved better than PEG when different substrate concentrations, temperatures, and enzyme loadings were investigated. PSM provides an opportunity to reduce enzyme dosage while still keeping the same extent of hydrolysis. We also investigated the effect of PSM on the simultaneous saccharification and fermentation of pretreated RS to lactic acid. Results showed that addition of 0.7g L-1 PSM improved the lactic acid production by 24% compared to the reference without PSM addition at 72h.

  19. Intermediate view synthesis from stereoscopic images

    Institute of Scientific and Technical Information of China (English)

    Lü Chaohui; An Ping; Zhang Zhaoyang

    2005-01-01

    A new method is proposed for synthesizing intermediate views from a pair of stereoscopic images. In order to synthesize high-quality intermediate views, the block matching method together with a simplified multi-window technique and dynamic programming is used in the process of disparity estimation. Then occlusion detection is performed to locate occluded regions and their disparities are compensated. After the projecton of the left-to-right and right-to-left disparities onto the intermediate image, intermediate view is synthesized considering occluded regions. Experimental results show that our synthesis method can obtain intermediate views with higher quality.

  20. Antibody immobilization on poly(L-lactic acid) nanofibers advantageously carried out by means of a non-equilibrium atmospheric plasma process

    Science.gov (United States)

    Dolci, L. S.; Liguori, A.; Merlettini, A.; Calzà, L.; Castellucci, M.; Gherardi, M.; Colombo, V.; Focarete, M. L.

    2016-07-01

    In the present study, the comparison between a conventional wet-chemical method and a non-equilibrium atmospheric pressure plasma process for the conjugation of biomolecules on the surface of poly(L-lactic acid) (PLLA) electrospun fibers is reported. Physico-chemical and morphological characteristics of chemically and plasma functionalized mats are studied and compared with those of pristine mats. The efficiency in biomolecules immobilization is assessed by the covalent conjugation of an antibody (anti-CD10) on the functionalized PLLA fibers. The achieved results highlight that the proposed plasma process enables antibodies to be successfully immobilized on the surface of PLLA fibers, demonstrating that non-equilibrium atmospheric pressure plasma can be an effective, highly flexible and environmentally friendly alternative to the still widely employed wet-chemical methods for the conjugation of biomolecules onto biomaterials.

  1. Recent progress in the development of solid catalysts for biomass conversion into high value-added chemicals

    Science.gov (United States)

    Hara, Michikazu; Nakajima, Kiyotaka; Kamata, Keigo

    2015-06-01

    In recent decades, the substitution of non-renewable fossil resources by renewable biomass as a sustainable feedstock has been extensively investigated for the manufacture of high value-added products such as biofuels, commodity chemicals, and new bio-based materials such as bioplastics. Numerous solid catalyst systems for the effective conversion of biomass feedstocks into value-added chemicals and fuels have been developed. Solid catalysts are classified into four main groups with respect to their structures and substrate activation properties: (a) micro- and mesoporous materials, (b) metal oxides, (c) supported metal catalysts, and (d) sulfonated polymers. This review article focuses on the activation of substrates and/or reagents on the basis of groups (a)-(d), and the corresponding reaction mechanisms. In addition, recent progress in chemocatalytic processes for the production of five industrially important products (5-hydroxymethylfurfural, lactic acid, glyceraldehyde, 1,3-dihydroxyacetone, and furan-2,5-dicarboxylic acid) as bio-based plastic monomers and their intermediates is comprehensively summarized.

  2. Intermediate inflation from rainbow gravity

    CERN Document Server

    Barrow, John D

    2013-01-01

    It is possible to dualize theories based on deformed dispersion relations and Einstein gravity so as to map them into theories with trivial dispersion relations and rainbow gravity. This often leads to "dual inflation" without the usual breaking of the strong energy condition. We identify the dispersion relations in the original frame which map into "intermediate" inflationary models. These turn out to be particularly simple: power-laws modulated by powers of a logarithm. The fluctuations predicted by these scenarios are near, but not exactly scale-invariant, with a red running spectral index. These dispersion relations deserve further study within the context of quantum gravity and the phenomenon of dimensional reduction in the ultraviolet.

  3. Intermediate Jacobians of moduli spaces

    CERN Document Server

    Arapura, D; Arapura, Donu; Sastry, Pramathanath

    1996-01-01

    Let $SU_X(n,L)$ be the moduli space of rank n semistable vector bundles with fixed determinant L on a smooth projective genus g curve X. Let $SU_X^s(n,L)$ denote the open subset parametrizing stable bundles. We show that if g>3 and n > 1, then the mixed Hodge structure on $H^3(SU_X^s(n, L))$ is pure of type ${(1,2),(2,1)}$ and it carries a natural polarization such that the associated polarized intermediate Jacobian is isomorphic J(X). This is new when deg L and n are not coprime. As a corollary, we obtain a Torelli theorem that says roughly that $SU_X^s(n,L)$ (or $SU_X(n,L)$) determines X. This complements or refines earlier results of Balaji, Kouvidakis-Pantev, Mumford-Newstead, Narasimhan-Ramanan, and Tyurin.

  4. The effect of delignification process with alkaline peroxide on lactic acid production from furfural residues

    Directory of Open Access Journals (Sweden)

    Yong Tang

    2012-11-01

    Full Text Available Furfural residues produced from the furfural industry were investigated as a substrate for lactic acid production by simultaneous saccharification and fermentation (SSF. Alkaline peroxide was used for delignification of furfural residues to improve the final lactic acid concentration. The residue was treated with 1.3% to 1.7% hydrogen peroxide at 80 °C for 1 h with a substrate concentration of 3.33%. SSF of furfural residues with different delignification degrees were carried out to evaluate the effect of delignification degree on lactic acid production. Using corn hydrolysates/ furfural residues as substrates, SSF with different media were carried out to investigate the effect of lignin on the interaction between enzymes and lactic acid bacteria. Lactic acid bacteria had a negative effect on cellulase, thus resulting in the reduction of enzyme activity. Lignin and nutrients slowed down the decreasing trend of enzyme activity. A higher delignification resulted in a slower fermentation rate and lower yield due to degradation products of lignin and the effect of lignin on the interaction between enzymes and lactic acid bacteria. For the purpose of lactic acid production, a moderate delignification (furfural residues with the lignin content of 14.8% was optimum.

  5. Poly(lactic-co-glycolic acid) conduit for repair of injured sciatic nerve A mechanical analysis*

    Institute of Scientific and Technical Information of China (English)

    Tao Yu; Changfu Zhao; Peng Li; Guangyao Liu; Min Luo

    2013-01-01

    Tensile stress and tensile strain directly affect the quality of nerve regeneration after bridging nerve defects by poly(lactic-co-glycolic acid) conduit transplantation and autogenous nerve grafting for sciatic nerve injury. This study col ected the sciatic nerve from the gluteus maximus muscle from fresh human cadaver, and established 10-mm-long sciatic nerve injury models by removing the ischium, fol owing which poly(lactic-co-glycolic acid) conduits or autogenous nerve grafts were transplanted. Scanning electron microscopy revealed that the axon and myelin sheath were torn, and the vessels of basilar membrane were obstructed in the poly(lactic-co-glycolic acid) con-duit-repaired sciatic nerve fol owing tensile testing. There were no significant differences in tensile tests with autogenous nerve graft-repaired sciatic nerve. Fol owing poly(lactic-co-glycolic acid) conduit transplantation for sciatic nerve repair, tensile test results suggest that maximum tensile load, maximum stress, elastic limit load and elastic limit stress increased compared with autogen-ous nerve grafts, but elastic limit strain and maximum strain decreased. Moreover, the tendencies of stress-strain curves of sciatic nerves were similar after transplantation of poly(lactic-co-glycolic acid) conduits or autogenous nerve grafts. Results showed that after transplantation in vitro for sciatic nerve injury, poly(lactic-co-glycolic acid) conduits exhibited good intensity, elasticity and plasticity, indicating that poly(lactic-co-glycolic acid) conduits are suitable for sciatic nerve injury repair.

  6. Intermediate processes in nuclear reactions

    International Nuclear Information System (INIS)

    The main results presented here cannot be interpreted in terms of the direct reaction model or the statistical models and one can more or less explicitely use some nuclear configurations for their interpretation. The first chapter deals with the so-called second order intermediate structures observed in the elastic and inelastic proton scattering on 66Zn and 70Ge targets in the energetic regions of some isobaric analog resonances. A formal theory for their interpretation is developed and the comparison with the experimental data is presented. New experimental results on the resonant structures observed in the elastic and inelastic scattering of 12C on 24Mg are presented in the second chapter. Detailed statistical analysis and their interpretation is presented too. Charge equilibration in deep inelastic collisions is the main subject of the third chapter. The experimental results obtained by the 98Mo + 154Sm collision at 12 MeV/n, a quantum treatment of a damped harmonic oscillator and the comparison with the experimental data are given. In the last chapter, some results on the existence of two other processes which could candidate to be involved in the main topic are presented. Those processes are: the fast fragmentation and preequilibrium charged particles emission. All these processes originate in the excitation of some simple configurations which can be seen on ''doorway'' states (''Hallway'' in the case of the second intermediate structures). The coupling of these states to other more complicated excitation modes of the nuclei and to outgoing channel=gives the possibility to study the nuclear dynamics. This justifies the interest for their detailed theoretical and experimental investigations. (author)

  7. Treatability of cheese whey for single-cell protein production in nonsterile systems: Part I. Optimal condition for lactic acid fermentation using a microaerobic sequencing batch reactor (microaerobic SBR) with immobilized Lactobacillus plantarum TISTR 2265 and microbial communities.

    Science.gov (United States)

    Monkoondee, Sarawut; Kuntiya, Ampin; Chaiyaso, Thanongsak; Leksawasdi, Noppol; Techapun, Charin; Kawee-Ai, Arthitaya; Seesuriyachan, Phisit

    2016-05-18

    Cheese whey contains a high organic content and causes serious problems if it is released into the environment when untreated. This study aimed to investigate the optimum condition of lactic acid production using the microaerobic sequencing batch reactor (microaerobic SBR) in a nonsterile system. The high production of lactic acid was achieved by immobilized Lactobacillus plantarum TISTR 2265 to generate an acidic pH condition below 4.5 and then to support single-cell protein (SCP) production in the second aerobic sequencing batch reactor (aerobic SBR). A hydraulic retention time (HRT) of 4 days and a whey concentration of 80% feeding gave a high lactic acid yield of 12.58 g/L, chemical oxygen demand (COD) removal of 62.38%, and lactose utilization of 61.54%. The microbial communities in the nonsterile system were dominated by members of lactic acid bacteria, and it was shown that the inoculum remained in the system up to 330 days. PMID:26178366

  8. Biodegradability of poly(lactic-co-glycolic acid) after femtosecond laser irradiation.

    Science.gov (United States)

    Shibata, Akimichi; Yada, Shuhei; Terakawa, Mitsuhiro

    2016-01-01

    Biodegradation is a key property for biodegradable polymer-based tissue scaffolds because it can provide suitable space for cell growth as well as tailored sustainability depending on their role. Ultrashort pulsed lasers have been widely used for the precise processing of optically transparent materials, including biodegradable polymers. Here, we demonstrated the change in the biodegradation of a poly(lactic-co-glycolic acid) (PLGA) following irradiation with femtosecond laser pulses at different wavelengths. Microscopic observation as well as water absorption and mass change measurement revealed that the biodegradation of the PLGA varied significantly depending on the laser wavelength. There was a significant acceleration of the degradation rate upon 400 nm-laser irradiation, whereas 800 nm-laser irradiation did not induce a comparable degree of change. The X-ray photoelectron spectroscopy analysis indicated that laser pulses at the shorter wavelength dissociated the chemical bonds effectively, resulting in a higher degradation rate at an early stage of degradation. PMID:27301578

  9. Exopolysaccharides produced by lactic acid bacteria: from health-promoting benefits to stress tolerance mechanisms.

    Science.gov (United States)

    Caggianiello, Graziano; Kleerebezem, Michiel; Spano, Giuseppe

    2016-05-01

    A wide range of lactic acid bacteria (LAB) is able to produce capsular or extracellular polysaccharides, with various chemical compositions and properties. Polysaccharides produced by LAB alter the rheological properties of the matrix in which they are dispersed, leading to typically viscous and "ropy" products. Polysaccharides are involved in several mechanisms such as prebiosis and probiosis, tolerance to stress associated to food process, and technological properties of food. In this paper, we summarize the beneficial properties of exopolysaccharides (EPS) produced by LAB with particular attention to prebiotic properties and to the effect of exopolysaccharides on the LAB-host interaction mechanisms, such as bacterial tolerance to gastrointestinal tract conditions, ability of ESP-producing probiotics to adhere to intestinal epithelium, their immune-modulatory activity, and their role in biofilm formation. The pro-technological aspect of exopolysaccharides is discussed, focusing on advantageous applications of EPS in the food industry, i.e., yogurt and gluten-free bakery products, since it was found that these microbial biopolymers positively affect the texture of foods. Finally, the involvement of EPS in tolerance to stress conditions that are commonly encountered in fermented beverages such as wine is discussed. PMID:27020288

  10. Exopolysaccharides Produced by Lactic Acid Bacteria and Bifidobacteria as Fermentable Substrates by the Intestinal Microbiota.

    Science.gov (United States)

    Salazar, Nuria; Gueimonde, Miguel; de Los Reyes-Gavilán, Clara G; Ruas-Madiedo, Patricia

    2016-07-01

    The functional food market, including products formulated to maintain a "healthy" gut microbiota, i.e. probiotics and prebiotics, has increased enormously since the end of the last century. In order to favor the competitiveness of this sector, as well as to increase our knowledge of the mechanisms of action upon human health, new probiotic strains and prebiotic substrates are being studied. This review discusses the use of exopolysaccharides (EPS), both homopolysaccharides (HoPS) and heteropolysaccharides (HePS), synthesized by lactic acid bacteria and bifidobacteria as potential prebiotics. These extracellular carbohydrate polymers synthesized by some gut inhabitants seem to be resistant to gastrointestinal digestion; these are susceptible as well to biodegradability by the intestinal microbiota depending on both the physicochemical characteristics of EPS and the pool of glycolytic enzymes harbored by microbiota. Therefore, although the chemical composition of these HoPS and HePS is different, both can be fermentable substrates by intestinal inhabitants and good candidates as prebiotic substrates. However, there are limitations for their use as additives in the food industry due to, on the one hand, their low production yield and, on the other hand, a lack of clinical studies demonstrating the functionality of these biopolymers. PMID:25675369

  11. Fabrication and biocompatibility of poly(l-lactic acid) and chitosan composite scaffolds with hierarchical microstructures.

    Science.gov (United States)

    Lou, Tao; Wang, Xuejun; Yan, Xu; Miao, Yu; Long, Yun-Ze; Yin, Hai-Lei; Sun, Bin; Song, Guojun

    2016-07-01

    The scaffold microstructure is crucial to reconstruct tissue normal functions. In this article, poly(l-lactic acid) and chitosan fiber (PLLA/CTSF) composite scaffolds with hierarchical microstructures both in fiber and pore sizes were successfully fabricated by combining thermal induced phase separation and salt leaching techniques. The composite scaffolds consisted of a nanofibrous PLLA matrix with diameter of 50-500nm, and chitosan fibers with diameter of about 20μm were homogenously distributed in the PLLA matrix as a microsized reinforcer. The composite scaffolds also had high porosity (>94%) and hierarchical pore size, which were consisted of both micropores (50nm-10μm) and macropores (50-300μm). By tailoring the microstructure and chemical composition, the mechanical property, pH buffer and protein adsorption capacity of the composite scaffold were improved significantly compared with those of PLLA scaffold. Cell culture results also revealed that the PLLA/CTSF composite scaffolds supported MG-63 osteoblast proliferation and penetration. PMID:27127062

  12. Effect of an acid filler on hydrolysis and biodegradation of poly-lactic acid (PLA)

    Science.gov (United States)

    Iozzino, Valentina; Speranza, Vito; Pantani, Roberto

    2015-12-01

    The use of biodegradable polymers is certainly an excellent strategy to solve many of the problems related to the disposal of the traditional polymers, whose accumulation in the environment is harmful and damaging. In order to optimize the use of biodegradable polymers, it is very important to understand and control the transformation processes, the structures and the morphologies resulting from the process conditions used to produce the articles and, not least, the biodegradation. The latter is strictly dependent on the just mentioned variables. The poly-lactic acid, PLA, is a biodegradable polymer. Many studies have been carried out on the degradation process of this polymer. In the course of this work we performed degradation tests on the PLA, with a specific D-isomer content, having amorphous structure, and in particular of biodegradation and hydrolysis. An acid chemical, fumaric acid, was added to PLA with the objective of controlling the rate of hydrolysis and of biodegradation. The hydrolysis process was followed, as function of time, by means of different techniques: pH variation, variation of weight of samples and variation of crystallinity degree and glass transition temperature using DSC analysis. The samples were also analyzed in terms of biodegradability by means of a homemade respirometer apparatus, in controlled composting conditions.

  13. Lactic acid fermentation in vegetable juices supplemented with different content of brewer’s yeast autolysate

    Directory of Open Access Journals (Sweden)

    Rakin Marica B.

    2005-01-01

    Full Text Available The work is concerned with the conditions for lactic acid fermentation in a mixture of beetroot (Beta vulgaris L juice and carrot (Daucus carota L juice and different content of brewer’s yeast autolysate with Lactobacillus plantarum A112 and with Lactobacillus acidophilus NCDO 1748.Both cultures showed good biochemical activity in these mixtures. The production of lactic acid has been stimulated using the higher content of brewer’s yeast autolysate. In these mixtures, L. plantarum A112 has shown better growth and lactic acid production than L. acidophilus NCDO 1748.

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

    OpenAIRE

    Pastink, M.I.

    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 knowledge in the area of amino acid metabolism. The three well-known lactic acid bacteria that were used in these studies...

  15. Inhibition of the Anaerobic Growth of Brochothrix thermosphacta by Lactic Acid

    OpenAIRE

    Grau, Frederick H.

    1980-01-01

    Brochothrix thermosphacta can grow aerobically in the presence of 210 mM l-lactate and anaerobically in its absence at pH values down to at least 5.5. Anaerobic growth is, however, inhibited by l-lactate, the concentration of undissociated lactic acid being the governing factor. Postrigor meat usually contains sufficient lactic acid to select against the anaerobic growth of B. thermosphacta. At least some Lactobacillaceae strains are more resistant to lactic acid and so their growth is favore...

  16. Study of Synthesis of Copoly (lactic acid/glycolic acid) by Direct Melt Polycondensation

    Institute of Scientific and Technical Information of China (English)

    LAN Ping; GAO Qin-wei; SHAO Hui-li; HU Xue-chao

    2005-01-01

    A two steps direct copolymerisation process was developed. The first step is to produce oligomer and then the oligomer of lactic acid/glycolic acid (90/10) is polymerized with binary catalyst tin chloride dihydrate/ptoluenesulfonic acid. In this way, the direct synthesis of copoly (lactic acid/glycolic acid) without any organic solvent was investigated. The properties and structures of products were characterized by nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), X-ray diffraction and so on. The results show that comparatively high molecular weight copolymer of lactic acid and glycolic acid can be prepared by direct processing under appropriate technological conditions.

  17. Water Uptake Behavior and Young Modulus Prediction of Composites Based on Treated Sisal Fibers and Poly(Lactic Acid

    Directory of Open Access Journals (Sweden)

    Ander Orue

    2016-05-01

    Full Text Available The main aim of this work was to study the effect of sisal fiber surface treatments on water uptake behavior of composites based on untreated and treated fibers. For this purpose, sisal fibers were treated with different chemical treatments. All surface treatments delayed the water absorption of fibers only for a short time of period. No significant differences were observed in water uptake profiles of composites based on fibers with different surface treatments. After water uptake period, tensile strength and Young modulus values of sisal fiber/poly(lactic acid (PLA composites were decreased. On the other hand, composites based on NaOH + silane treated fibers showed the lowest diffusion coefficient values, suggesting that this treatment seemed to be the most effective treatment to reduce water diffusion rate into the composites. Finally, Young modulus values of composites, before water uptake period, were predicted using different micromechanical models and were compared with experimental data.

  18. Lactic acid-mediated tandem one-pot synthesis of 2-aminothiazole derivatives: A rapid, scalable, and sustainable process

    Directory of Open Access Journals (Sweden)

    Mohan Reddy Bodireddy

    2016-12-01

    Full Text Available Environmentally benign and biodegradable lactic acid is identified as alternative solvent and catalyst for the tandem one-pot synthesis of Hantzsch 2-aminothiazole derivatives (4 from readily available aralkyl ketones (1 through in situ regioselective α-bromination using N-bromosuccinimide (2 followed by heterocyclization using thiourea (3 at 90–100°C. The major advantages of the present method include short reaction times (10–15 min, practical, simple to perform, easy work-up, good yield of products (up to 96%, productive for large-scale applications, free from apply of α-bromoketones (lachrymator as substrates, avoids column purification. Hence, the present method meets with the concepts of both Wender’s “ideal synthesis” and sustainable chemical process.

  19. A new and direct synthesis of lactic acid from acrylic acid using an excimer laser with high intensity

    International Nuclear Information System (INIS)

    A new and direct method of XeF (351 nm) laser irradiation of acrylic acid 1 solution containing H2O2 are described for the chemical synthesis of lactic acid 2. Increase in the yield strongly depended on the irradiation dose and H2O2 feeding rate, and the formation of 2 showed the quantum yield, 0.3, and the selectivity, 50%, at the maximum yield. Product analysis indicated that OH radicals formed with high density by the laser-photolysis of H2O2 are equally bonded to the carbons of α- and β-positions of 1 to produce 2 and 3-hydroxy propanoic acid with ratio of 1 to 1. (author)

  20. Synthesis and in vitro bio degradation of poly(ethylene adipate- co-D,L-lactic acid copolymers (PLEA

    Directory of Open Access Journals (Sweden)

    Bakouri Hichem

    2014-09-01

    Full Text Available The present research mainly focused on the synthesis and study of bio degradation of poly (ethylene adipate-co-D,L-lactic acid. PLEA were prepared via ring opening polymerization from D,L-lactide and poly(ethylene adipate. PLEA was characterized by 1H NMR spectra and DSC; results showed that those properties showed high dependence on its composition.In vitro degradation behaviors of PLEA have been systematically investigated up to 12 weeks in phosphate buffer saline solution at 37 °C. The weight and polymer molecular weight were measured as a function of degradation time. Bacterial degradation was completed by investigating the physico-chemical properties using spectroscopy FTIR and DSC.

  1. SCREENING, ISOLATION, IDENTIFICATION OF HOMOFERMENTATIVE BACILLI AND HOMOFERMENTATIVE COCCI FROM IDLI BATTER AND ESTIMATION OF LACTIC ACID PRODUCED BY THEM TO GET THE HIGHEST YIELD GIVING ORGANISM

    OpenAIRE

    Pathak LP*, Mali RD and PS Deshmukh

    2013-01-01

    Lactic acid is an organic acid produced by bacterial fermentation. It has several industrial applications. Lactic acid has been produced on commercial scale using various Lactic acid bacteria.   Lactobacillus leishmanii is the most commonly employed species4. Screening for high yielding Lactic acid producing bacillus or coccus from natural source will improve its commercial value. Lactic acid bacteria include some rod shaped genera and some genera with the morphology, cocci2. They are abundan...

  2. Development of Mucosal Vaccines Based on Lactic Acid Bacteria

    Science.gov (United States)

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

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

  3. Current taxonomy of phages infecting lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Jennifer eMahony

    2014-01-01

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

  4. Screening and characterization of novel bacteriocins from lactic acid bacteria.

    Science.gov (United States)

    Zendo, Takeshi

    2013-01-01

    Bacteriocins produced by lactic acid bacteria (LAB) are expected to be safe antimicrobial agents. While the best studied LAB bacteriocin, nisin A, is widely utilized as a food preservative, various novel ones are required to control undesirable bacteria more effectively. To discover novel bacteriocins at the early step of the screening process, we developed a rapid screening system that evaluates bacteriocins produced by newly isolated LAB based on their antibacterial spectra and molecular masses. By means of this system, various novel bacteriocins were identified, including a nisin variant, nisin Q, a two-peptide bacteriocin, lactococcin Q, a leaderless bacteriocin, lacticin Q, and a circular bacteriocin, lactocyclicin Q. Moreover, some LAB isolates were found to produce multiple bacteriocins. They were characterized as to their structures, mechanisms of action, and biosynthetic mechanisms. Novel LAB bacteriocins and their biosynthetic mechanisms are expected for applications such as food preservation and peptide engineering. PMID:23649268

  5. Metformin-Associated Acute Kidney Injury and Lactic Acidosis

    Directory of Open Access Journals (Sweden)

    David Arroyo

    2011-01-01

    Full Text Available Objectives. Metformin is the preferred oral antidiabetic agent for type 2 diabetes. Lactic acidosis is described as a rare complication, usually during an acute kidney injury (AKI. Material and Methods. We conducted a prospective observational study of metformin-associated AKI cases during four years. 29 cases were identified. Previous renal function, clinical data, and outcomes were recorded. Results. An episode of acute gastroenteritis precipitated the event in 26 cases. Three developed a septic shock. Three patients died, the only related factor being liver dysfunction. More severe metabolic acidosis hyperkalemia and anemia were associated with higher probabilities of RRT requirement. We could not find any relationship between previous renal dysfunction and the outcome of the AKI. Conclusions. AKI associated to an episode of volume depletion due to gastrointestinal losses is a serious complication in type 2 diabetic patients on metformin. Previous renal dysfunction (mild-to-moderate CKD has no influence on the severity or outcome.

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

    Science.gov (United States)

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

    2010-04-01

    We compared immunomodulatory properties of 11 strains of lactic acid bacteria as well as their capacity to enhance sublingual immunotherapy efficacy in a murine asthma model. Two types of bacterial strains were identified, including: (i) potent inducers of IL-12p70 and IL-10 in dendritic cells, supporting IFN-gamma and IL-10 production in CD4+ T cells such as Lactobacillus helveticus; (ii) pure Th1 inducers such as L. casei. Sublingual administration in ovalbumin-sensitized mice of L. helveticus, but not L. casei, reduced airways hyperresponsiveness, bronchial inflammation and proliferation of specific T cells in cervical lymph nodes. Thus, probiotics acting as a Th1/possibly Treg, but not Th1 adjuvant, potentiate tolerance induction via the sublingual route. PMID:20175969

  7. Variations in prebiotic oligosaccharide fermentation by intestinal lactic acid bacteria.

    Science.gov (United States)

    Endo, Akihito; Nakamura, Saki; Konishi, Kenta; Nakagawa, Junichi; Tochio, Takumi

    2016-03-01

    Prebiotic oligosaccharides confer health benefits on the host by modulating the gut microbiota. Intestinal lactic acid bacteria (LAB) are potential targets of prebiotics; however, the metabolism of oligosaccharides by LAB has not been fully characterized. Here, we studied the metabolism of eight oligosaccharides by 19 strains of intestinal LAB. Among the eight oligosaccharides used, 1-kestose, lactosucrose and galactooligosaccharides (GOSs) led to the greatest increases in the numbers of the strains tested. However, mono- and disaccharides accounted for more than half of the GOSs used, and several strains only metabolized the mono- and di-saccharides in GOSs. End product profiles indicated that the amounts of lactate produced were generally consistent with the bacterial growth recorded. Oligosaccharide profiling revealed the interesting metabolic manner in Lactobacillus paracasei strains, which metabolized all oligosaccharides, but left sucrose when cultured with fructooligosaccharides. The present study clearly indicated that the prebiotic potential of each oligosaccharide differs. PMID:26888650

  8. Thermogravimetric and DSC testing of poly(lactic acid) nanocomposites

    International Nuclear Information System (INIS)

    Highlights: • The presence of nanoadditivities in PLA matrix improves thermal stability of PLA. • Shielding effect main reason for PLA thermal stability by nanofillers. • Thermal degradation suppression in UV-irradiated PLA by the removing of unstable compounds. - Abstract: Polymer nanocomposites based on poly(lactic acid), PLA, and two types of nanofillers: nanosilver and nanoclay were obtained by casting method. The thermal properties of PLA and nanocomposites have been studied by thermogravimetric analysis (TA) and differential scanning calorimetry (DSC). All samples have been UV-irradiated and the effect of photoprocess on their thermal stability has been estimated. It was found that nanoadditives and UV irradiation causes an increase of the activation energy of PLA thermal decomposition. DSC result supplies information on glass transition and crystallization/melting processes in PLA in the presence of nanosilver or nanoclay, also after exposure to UV

  9. SURFACE OF GELATIN MODIFIED POLY(L-LACTIC ACID) FILM

    Institute of Scientific and Technical Information of China (English)

    Xin Hou; Bao-long Zhang; Feng She; Yuan-lu Cui; Ke-yu Shi; Kang-de Yao

    2003-01-01

    In this paper, the surface structure of poly(L-lactic acid) (PLLA) film modified with gelatin was investigated. The PLLA film specimens were treated directly with aqueous alkali solution to provide their surfaces with carboxyl groups, so that these functional groups could become the reactive sites for gelatin immobilization. The functional groups of the PLLA films were identified by ATR-FTIR spectra and XPS spectra, the changes in surface morphology were observed by using environmental scanning electron microscopy (ESEM), and the hydrophilicity of modified PLLA films was examined by water contact angle measurement. Experimental results showed that the gelatin was immobilized with water-soluble carbodiimide (EDC) onto the PLLA film's surfaces, and the gelatin content on the polymer surface was related to carboxylic group formed in the controlled hydrolysis process. Rough surfaces caused by hydrolysis will predominantly favor the adhesion and growth of cell; and the hydrophilicity of these surfaces after the modification procedure is enhanced.

  10. COMPARISON OF OCCURENCE LACTIC ACID BACTERIA IN CHOSEN YOGURTS

    Directory of Open Access Journals (Sweden)

    Silvia Pinterová

    2010-11-01

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

  11. Physicochemical properties of poly(lactic acid-co-glycolic acid film modified via blending with poly(butyl acrylate-co-methyl methacrylate

    Directory of Open Access Journals (Sweden)

    Guoquan Zhu

    2013-01-01

    Full Text Available A series of poly(lactic acid-co-glycolic acid (PLGA/poly(butyl acrylate-co-methyl methacrylate (P(BA-co-MMA blend films with different P(BA-co-MMA mole contents were prepared by casting the polymer blend solution in chloroform. Surface morphologies of the PLGAP(BA-co-MMA blend films were studied by scanning electron microscopy (SEM. Thermal, mechanical, and chemical properties of PLGAP(BA-co-MMA blend films were investigated by differential scanning calorimeter (DSC, thermogravimetric analysis (TGA, tensile tests, and surface contact angle tests. The introduction of P(BA-co-MMA could modify the properties of PLGA films.

  12. Absolute configuration and enantiomeric composition of partially resolved mandelic, atrolactic and lactic acids by {sup 1}H NMR of their (S)-2-methylbutyl esters

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Francisco A. da C.; Mendes, Maricleide P. de L.; Fonseca, Neuracy C. da, E-mail: fandrade@ufba.br [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Instituto de Quimica. Departamento de Quimica Organica

    2013-06-15

    The mandelic, atrolactic and lactic acid esters of the (S)-2-methyl-1-butanol were examined as diastereomeric derivatives for the stereochemical analysis of the mentioned acids by {sup 1}H nuclear magnetic resonance (NMR) at 300 MHz. The diastereomeric esters showed distinctive signals in the methylenic absorption range (O-CH{sub 2}-CH) of the alcoholic moieties. By spectral analysis at this region, absolute configurations were attributed, chemical shifts of the correspondent pro-(R) and pro-(S) hydrogens from the methylene group of the alcohol moiety were assigned and enantiomeric compositions were determined for the original partially resolved acids. (author)

  13. Absolute configuration and enantiomeric composition of partially resolved mandelic, atrolactic and lactic acids by 1H NMR of their (S)-2-methylbutyl esters

    International Nuclear Information System (INIS)

    The mandelic, atrolactic and lactic acid esters of the (S)-2-methyl-1-butanol were examined as diastereomeric derivatives for the stereochemical analysis of the mentioned acids by 1H nuclear magnetic resonance (NMR) at 300 MHz. The diastereomeric esters showed distinctive signals in the methylenic absorption range (O-CH2-CH) of the alcoholic moieties. By spectral analysis at this region, absolute configurations were attributed, chemical shifts of the correspondent pro-(R) and pro-(S) hydrogens from the methylene group of the alcohol moiety were assigned and enantiomeric compositions were determined for the original partially resolved acids. (author)

  14. Bacteriocins produced by lactic acid bacteria: A review

    Directory of Open Access Journals (Sweden)

    Vesković-Moračanin Slavica M.

    2014-01-01

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

  15. A comparative study on experimental and theoretical ESR spectra of lactic acid polymers irradiated by gamma rays

    International Nuclear Information System (INIS)

    Homo polymers of L-Lactic acid (LLA) and D,L-Lactic acid (DLLA), being biocompatible and absorbable in body iluids have recently found wide applications in the preparation of surgical sutures, controlled drug delivery systems, burn wound coverings etc. For sometime these polymers have also been prepared in the form of plates and screws for mandibular fracture fixation, tissue implants. Their chemical sensitivities against relatively high temperatures and hydrolysis with water make them unsuitable for conventional sterilization techniques like hot water vapor and ethylene oxide. Sterilization of the devices made of these polymers is therefore possible by gamma ray irradiation. This has initiated a number of research works in order to better understand the effects of ionizing radiation on this polymer. The aim of this study is to determine the possible radical types, their location on macromolecular structure and the reasons for peak shifts in the experimental and theoretical ESR spectra. Polymer samples were irradiated in air and in vacuum (10□□ torr) to 25 kGy sterilization dose at the dose rate 0.59 kGy/h and at room temperature by 60Co γ-irradiator. Despite being chemically the same radical type, some differences were observed in the splitting of peaks of PLLA and PDLLA samples. These differences were determined and compared by means of fitting studies. Firstly, PLLA was characterized and its g and hyperfine splitting values were found as 2.0032±0.0002 and 20.37±0.2. In the characterization study of PDLLA, it was found that one of the nearest two radicals was on the upper and the other one was on the lower plane of PDLLA chain. (author)

  16. Mechanism of oxovanadium (IV)-catalysed and uncatalysed bromate oxidation of lactic acid in acid medium: evaluation of composite and individual kinetic and thermodynamic parameters

    International Nuclear Information System (INIS)

    Uncatalysed acid bromate oxidation of lactic acid (LA) exhibits fractional order (1.6) in [acid] and first order each in [Br(V)] and [LA]. Kinetic isotope effect (kH/kD=1) is absent, however an inverse solvent isotope effect (kH2O/kD2O=1.78 at 313 K) is observed. The mechanism proposed consists of a rate determining formation of bromate ester due to the nucleophilic attack by the alcoholic/hydroxyl group at the bromine atom of HOBrO2/H2O2Br+O, followed by a fast disproportionation of the ester through C-C bond cleavage to form products. Oxovanadium(IV)-catalysed LA-Br(V) reaction exhibits second order in [acid], fractional order in [lactic acid] and first order each in [VOSO4] and [oxidant]. The envisaged mechanism assumes a ternary complex formation involving a binary complex of LA and V(IV) and protonated bromate, which subsequently decomposes to the intermediate/products. The rate constants involved for each step of the reactions are evaluated along with their thermodynamic parameters. (author)

  17. Chemical Decontamination of Campylobacter jejuni on Chicken Skin and Meat

    DEFF Research Database (Denmark)

    Riedel, Charlotte Tandrup; Brøndsted, Lone; Rosenquist, Hanne;

    2009-01-01

    This study evaluated the effectiveness of 11 chemical compounds to reduce Campylobacter jejuni on chicken skin and meat samples dipped in chemical solutions. Treatment of skin samples for 1 min using tartaric acid (2%) and caprylic acid sodium salt (5%) caused reductions of C. jejuni NCTC11168......, which were not significantly different from the reduction obtained by sterile water (0.95 log). Statistically larger reductions (1.57 to 3.81 log) were caused by formic acid (2%), lactic acid (2.5%), trisodium phosphate (10%), capric acid sodium salt (5%), grapefruit seed extract (1......, sterile water and lactic acid caused considerably larger reductions on skin than on meat, whereas the opposite was seen for caprylic acid sodium salt. In conclusion, this study has identified chemicals with substantial reduction effects on C. jejuni. The analysis has further emphasized that treatment time...

  18. On financial equilibrium with intermediation costs

    DEFF Research Database (Denmark)

    Markeprand, Tobias Ejnar

    2008-01-01

    This paper studies the set of competitive equilibria in financial economies with intermediation costs. We consider an arbitrary dividend structure, which includes options and equity with limited liabilities.We show a general existence result and upper-hemi continuity of the equilibrium...... correspondence. Finally, we prove that when intermediation costs approach zero, unbounded volume of asset trades is a necessary and sufficient condition, provided that, there is no financial equilibrium without intermediation costs....

  19. FINANCIAL INTERMEDIATION, ENTREPRENEURSHIP AND ECONOMIC GROWTH

    OpenAIRE

    Wenli Cheng

    2007-01-01

    This paper presents a simple general equilibrium model of financial intermediation, entrepreneurship and economic growth. In this model, the role of financial intermediation is to pool savings and to lend the pooled funds to an entrepreneur, who in turn invests the funds in a new production technology. The adoption of the new production technology improves individual real income. Thus financial intermediation promotes economic growth through affecting individuals’ saving behaviour and enabl...

  20. How should Financial Intermediation Services be Taxed?

    OpenAIRE

    Lockwood, Ben

    2010-01-01

    This paper considers the optimal taxation of savings intermediation and payment services in a dynamic general equilibrium setting, when the government can also use consumption and income taxes. When payment services are used in strict proportion to final consumption, and the cost of intermediation services is fixed and the same across firms, the optimal taxes are generally indeterminate. But, when firms differ exogenously in the cost of intermediation services, the tax on savings intermediati...

  1. Experimental Studies of Toxicity on HNIW and Its Intermediates

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ying; CHEN Shu-sen; JIN Shao-hua; CUI Zhao-kuan

    2006-01-01

    The polycyclic nitramine hexanitrohexaazaisowurtane(HNIW) is a compound of high energy density. HNIW can replace 1, 3, 5-trinitro-1, 3, 5-triazacyclohexane(RDX)or HMX, but its toxicity is unknown. In this paper,HNIW, hexabenzylhexaazaisowurtzitane ( HBIW ), tetraacetyldibenzulhexaazaisowurtzitane ( TADBIW ), tetraacetyldiformylhexaazaisowurtzitane(TADFIW) and tetraacetylhexaazaisowurtzitane(TAIW), which are intermediates of the synthesis of the HNIW, were selected as the tested objects in acute toxicity test, acute eye stimulation test and skin irritation test according to the standards of "chemical product testing method-401: acute oral toxicity test", "chemical product testing means-405: acute eye irritation/corrosion test" and "chemical product testing means-404: acute dermal irritation/corrosion test" of National Circumstance Protect Bureau. The results show that all of the five objects have no toxicity, no stimulation to eye and skin under the tested conditions.

  2. Experiments in intermediate energy physics

    Energy Technology Data Exchange (ETDEWEB)

    Dehnhard, D.

    2003-02-28

    Research in experimental nuclear physics was done from 1979 to 2002 primarily at intermediate energy facilities that provide pion, proton, and kaon beams. Particularly successful has been the work at the Los Alamos Meson Physics Facility (LAMPF) on unraveling the neutron and proton contributions to nuclear ground state and transition densities. This work was done on a wide variety of nuclei and with great detail on the carbon, oxygen, and helium isotopes. Some of the investigations involved the use of polarized targets which allowed the extraction of information on the spin-dependent part of the triangle-nucleon interaction. At the Indiana University Cyclotron Facility (IUCF) we studied proton-induced charge exchange reactions with results of importance to astrophysics and the nuclear few-body problem. During the first few years, the analysis of heavy-ion nucleus scattering data that had been taken prior to 1979 was completed. During the last few years we created hypernuclei by use of a kaon beam at Brookhaven National Laboratory (BNL) and an electron beam at Jefferson Laboratory (JLab). The data taken at BNL for a study of the non-mesonic weak decay of the A particle in a nucleus are still under analysis by our collaborators. The work at JLab resulted in the best resolution hypernuclear spectra measured thus far with magnetic spectrometers.

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

    DEFF Research Database (Denmark)

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

    1998-01-01

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

  4. Fermentation of Prefermented and Extruded Rice Flour by Lactic Acid Bacteria from Sikhae

    DEFF Research Database (Denmark)

    Lee, C. H.; Min, K. C.; Souane, M.;

    1992-01-01

    decreased in the same substrates. The final pH of the cereal lactic beverage was in the range of 3.4 - 4.1, L. mesenteroides(sikhae) had relatively higher pH compared to other lactic acid bacteria. L. mesenteroides(sikhae) produced apple juice-like flavor, while L. plantarum, L. casei and L. lactis yielded......The acid- and flavor-forming properties of Lactobacillus plantarum and Leuconostoc mesenteroides isolated from Sikhae, a Korean traditional lactic acid fermented fish product, were examined and compared to those of Lactobacillus casei and Lactococcus lactis subsp. diacetylactis DRC3. The effects of...... prefermentation of rice flour in solid-state with Bacillus laevolacticus and Saccharomyces cerevisiae, extrusion cooking and addition of soymilk as the substrate of lactic acid fermentation were tested. Extrusion cooking and prefermentation of rice increased the soluble solid and sugar contents before malt...

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

    Science.gov (United States)

    Lactic acid bacteria (LAB) frequently contaminate commercial fuel ethanol fermentations, reducing yields and decreasing profitability of biofuel production. Microorganisms from environmental sources in different geographic regions of Thailand were tested for antibacterial activity against LAB. Fou...

  6. Lactic acidosis, potassium, and the heart rate deflection point in professional road cyclists

    OpenAIRE

    Lucia, A.; Hoyos, J; Santalla, A; Perez, M; Carvajal, A.; Chicharro, J.

    2002-01-01

    Objective: To determine the influence of lactic acidosis, the Bohr effect, and exercise induced hyperkalaemia on the occurrence of the heart rate deflection point (HRDP) in elite (professional) cyclists.

  7. Molecular Characterization of Intrinsic and Acquired antibiotic resistance in lactic Acid bacteria and Bifidobacteria

    NARCIS (Netherlands)

    Ammor, M.S.; Flórez, A.B.; Hoek, van A.H.A.M.; Reyes-Gavilan, de los C.G.; Aarts, H.J.M.; Margolles, A.; Mayo, B.

    2008-01-01

    The minimum inhibitory concentrations (MICs) of 6 different antibiotics (chloramphenicol, clindamycin, erythromycin, streptomycin, tetracycline and vancomycin) were determined for 143 strains of lactic acid bacteria and bifidobacteria using the Etest. Different MICs were found for different species

  8. Comparative analysis of microbial community of novel lactic acid fermentation inoculated with different undefined mixed cultures.

    Science.gov (United States)

    Liang, Shaobo; Gliniewicz, Karol; Mendes-Soares, Helena; Settles, Matthew L; Forney, Larry J; Coats, Erik R; McDonald, Armando G

    2015-03-01

    Three undefined mixed cultures (activated sludge) from different municipal wastewater treatment plants were used as seeds in a novel lactic acid fermentation process fed with potato peel waste (PPW). Anaerobic sequencing batch fermenters were run under identical conditions to produce predominantly lactic acid. Illumina sequencing was used to examine the 16S rRNA genes of bacteria in the three seeds and fermenters. Results showed that the structure of microbial communities of three seeds were different. All three fermentation products had unique community structures that were dominated (>96%) by species of the genus Lactobacillus, while members of this genus constituted <0.1% in seeds. The species of Lactobacillus sp. differed among the three fermentations. Results of this study suggest the structure of microbial communities in lactic acid fermentation of PPW with undefined mixed cultures were robust and resilient, which provided engineering prospects for the microbial utilization of carbohydrate wastes to produce lactic acid. PMID:25545096

  9. Systematic Procedure for Integrated Process Operation: Reverse Electro-Enhanced Dialysis (REED) during Lactic Acid Fermentation

    DEFF Research Database (Denmark)

    Prado Rubio, Oscar Andres; Jørgensen, Sten Bay; Jonsson, Gunnar Eigil

    2011-01-01

    The integration of lactic acid fermentation and Reverse Electro-Enhanced Dialysis (REED) is investigated based upon previously developed mathematical models. A goal driven process and operation design procedure is proposed and partially investigated. The conceptual analysis of the processes...

  10. Systematic Procedure for Integrated Process Operation: Reverse Electro-Enhanced Dialysis (REED) during Lactic Acid Fermentation

    DEFF Research Database (Denmark)

    Prado Rubio, Oscar Andres; Jørgensen, Sten Bay; Jonsson, Gunnar Eigil

    The integration of lactic acid fermentation and Reverse Electro-Enhanced Dialysis (REED) is investigated based upon previously developed mathematical models. A goal driven process and operation design procedure is proposed and partially investigated. The conceptual analysis of the processes...

  11. Kinetics of free radical decay reactions in lactic acid homo and copolymers irradiated to sterilization dose

    International Nuclear Information System (INIS)

    The kinetics of free radical decay reactions of poly(L-Lactic acid), poly(DL-Lactic acid) and random copolymer of lactic and glycolic acid have been investigated for decays taking place in air and in vacuum. The change in ESR lines of γ-irradiated polymers have been followed over a long time period. The decay has been found to follow neither simple first-order nor second-order kinetics. Various kinetic approaches including composite first or second-order mechanisms and diffusion-controlled first or second-order equations were determined to be also unsatisfactory. The decay of radicals in bulk irradiated lactic acid homo and copolymers was found to be best described when the second-order non-classical equation with time dependent rate constant approach was used. (Author)

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

    OpenAIRE

    Nour-Eddine, Karam; Halima, Zadi-Karam; Mourad, Kacem

    2004-01-01

    This study was undertaken with the aim of obtaining lactic acid bacteria with the ability to ferment olives for possible use as starter cultures. For this reason, 32 isolates of lactic acid bacteria isolated from the spontaneous fermentation of green olives were characterized and identified on the basis of morphological and biochemical criteria. 14 of them were identified as Lactococcus lactis, 11 isolates as Lactobacillus plantarum and 7 isolates as Enterococcus sp. Of the 18 isolates examin...

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

    OpenAIRE

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

    2002-01-01

    In the present work, the effects of several lactic acid bacteria on the immune response of turbot (Scophthalmus 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 chemiluminescent (CL) response after 24 h of incubation. Nitric oxide (NO) was also significantly enhanced by this bacterium after 72 h of incubation with either viable (103 an...

  14. Synthesis and Characterization of Chitosan-g-poly(D, L-lactic acid) Copolymer

    Institute of Scientific and Technical Information of China (English)

    Hua YANG; Shao Bing ZHOU; Xian Mo DENG

    2005-01-01

    Biodegradable chitosan-g-poly (D, L-lactic acid) copolymers were prepared via two methods. (1) The lactide was grafted onto hydroxyl groups of chitosan by using macromolecular initiator sodium of trimethylsilyl-chitosan, (2) poly (D,L-lactic acid)(PLA) with low molecular weight can be linked to the amino group by coupling activated PLA to trimethylsilyl-chitosan. Two graft copolymers had hydrophilic-hydrophobic character and can be applied as carriers for drug delivery.

  15. Antimicrobial properties of lactic acid bacteria isolated from uruguayan artisan cheese

    OpenAIRE

    Martín Fraga Cotelo; Karen Perelmuter Schein; Sheila Solange Giacaman Salvo; Pablo Miguel Zunino Abirad; Silvana Beatriz Carro Techera

    2013-01-01

    Uruguayan artisan cheese is elaborated with raw milk and non-commercial starters. The associated native microbiota may include lactic acid bacteria and also potentially pathogenic bacteria. Lactic acid bacteria were isolated from artisan cheese, raw milk, and non-commercial starter cultures, and their potential bacteriocin production was assessed. A culture collection of 509 isolates was obtained, and five isolates were bacteriocin-producers and were identified as Enterococcus durans,Lactobac...

  16. LACTIC ACID BACTERIA FLORA OF KONYA KUFLU CHEESE: A TRADITIONAL CHEESE FROM KONYA PROVINCE IN TURKEY

    OpenAIRE

    Ziba Guley; Harun R. Uysal; Sevda Kilic

    2014-01-01

    The aim of this study was to characterize the lactic acid bacteria flora of mature Konya Kuflu cheese. Konya Kuflu cheese is a traditional blue cheese which is produced from raw milk without starter culture addition and mould growth occurs in uncontrolled conditions during its ripening. Lactic acid bacteria (LAB) isolated from 9 mature Konya Kuflu cheese samples were investigated using a combination of conventional biochemical tests, API test kits, and molecular approaches. For some isolates,...

  17. Isolation and identification of indigenous lactic acid bacteria from North Sumatra river buffalo milk

    OpenAIRE

    2015-01-01

    Buffalo milk is a source of various lactic acid bacteria (LAB) which is potential as culture starter as well as the probiotic. This study was conducted to isolate and identify LAB from indigenous North Sumatra river buffalo milk. Lactic acid bacteria was isolated and grown in medium De Man Rogosa Sharpe Agar (MRSA). The isolation was conducted to obtain pure isolate. The identification of LAB was studied in terms of morphology, physiology, biochemistry and survival on low pH. Morphology test...

  18. Immune Modulation Capability of Exopolysaccharides Synthesised by Lactic Acid Bacteria and Bifidobacteria

    OpenAIRE

    Hidalgo-Cantabrana, Claudio; López, Patricia; Gueimonde Fernández, Miguel; González de los Reyes-Gavilán, Clara; Suárez, Ana; Margolles Barros, Abelardo; Ruas-Madiedo, Patricia

    2012-01-01

    During recent years, the exopolysaccharides (EPS) produced by some strains of lactic acid bacteria and bifidobacteria have attracted the attention of researchers, mainly due to their potential technological applications. However, more recently, it has been observed that some of these EPS present immunomodulatory properties, which suggest a potential effect on human health. Whereas EPS from lactic acid bacteria have been studied in some detail, those of bifidobacteria largely remain uncharacte...

  19. Lactic acid bacteria in Hamei and Marcha of North East India

    OpenAIRE

    Tamang, J. P.; Dewan, S.; Tamang, B.; Rai, A; Schillinger, U.; Holzapfel, W. H.

    2007-01-01

    Hamei and Marcha are mixed dough inocula used as starters for preparation of various indigenous alcoholic beverages in Manipur and Sikkim in India, respectively. These starters are traditionally prepared from rice with wild herbs and spices. Samples of Hamei and Marcha, collected from Manipur and Sikkim, respectively, were analysed for lactic acid bacterial composition. The population of lactic acid bacteria (LAB) was 6.9 and 7.1 Log cfu/g in Hamei and Marcha, respectively. On the basis of ph...

  20. Survival of Listeria monocytogenes, Listeria innocua, and Lactic acid bacteria species in chill brine

    OpenAIRE

    Meadows, Bridget Archibald

    2004-01-01

    SURVIVAL OF LISTERIA MONOCYTOGENES, LISTERIA INNOCUA, AND LACTIC ACID BACTERIA SPECIES IN CHILL BRINES Bridget Archibald Meadows (ABSTRACT) Listeria monocytogenes is the major pathogen in ready-to-eat meat products such as deli meats and frankfurters. Contamination can occur via the salt brines that are used to cool thermally processed meats. Both L. monocytogenes and lactic acid bacteria can grow and thrive under these brine conditions, and may become competitive with each ot...

  1. The effects of a food product containing lactic acid on the activity of acetylcholinesterase

    OpenAIRE

    Andre-Michael Beer; Julian Lukanov; Yordanka Uzunova; Plamen Sagortchev

    2012-01-01

    Objective: Patients reported that a food product containing lactic acid improved their memory and thought processes. The ingredients of the tested food product are compound substances and smooth muscle fibre, the appropriate medium in which to analyse their effects. Acetylcholinesterase inhibitors are used to treat memory loss and failing thought performance. The aim of this study was to compare the effects of the lactic acid food product with the effects of acetylcholinesterase inhibitors. M...

  2. Naturally fermented Jijelian black olives: microbiological characteristics and isolation of lactic acid bacteria

    OpenAIRE

    Karam, Nour-Eddine; Leghouchi, Essaid; Boudjerda, Jamel; Idoui, Tayeb

    2009-01-01

    A study of the microflora of traditionally fermented black olives in Eastern Algeria is presented. A count of the following microbial groups was carried out: mesophilic bacteria, enterobacteria, lactic acid bacteria (LAB), staphylococci and yeast. In a second phase, the identification and assessment of the technological traits of LAB was performed. Seventeen lactic acid bacteria were isolated and identified. These isolates were represented by two genera: Lactobacillus and Leuconostoc. The res...

  3. Lactic acid fermentation in vegetable juices supplemented with different content of brewer’s yeast autolysate

    OpenAIRE

    Rakin Marica B.; Baras Josip K.; Vukašinović Maja S.

    2005-01-01

    The work is concerned with the conditions for lactic acid fermentation in a mixture of beetroot (Beta vulgaris L) juice and carrot (Daucus carota L) juice and different content of brewer’s yeast autolysate with Lactobacillus plantarum A112 and with Lactobacillus acidophilus NCDO 1748.Both cultures showed good biochemical activity in these mixtures. The production of lactic acid has been stimulated using the higher content of brewer’s yeast autolysate. In these mixtures, L. plantarum A112 has ...

  4. A Novel Lactic Acid Bacteria Growth-stimulating Peptide from Broad Bean (Vicia faba .) Protein Hydrolysates

    OpenAIRE

    Ping Xiao; Yuan Liu; Rizwan-ur-Rehman; Ran Kang; Yanping Wang

    2015-01-01

    In this study, broad bean protein hydrolysates (BPH) produced by alcalase with strong-stimulating activity for lactic acid bacteria (LAB) was first time reported. In order to obtain the key peptide that have growth-stimulating activity for lactic acid bacteria (LAB), gel filtration chromatography and Reverse Phase High Performance Liquid Chromatography (RP-HPLC) were applied to isolate and purify the peptides from BPH. Finally, F4-2 elicited the highest activity for LAB, corresponding to amin...

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

    OpenAIRE

    Argyri, Anthoula; Zoumpopoulou, Georgia; Karatzas, Kimon Andreas; Tsakalidou, Effie; Nychas, George John; Panagou, Efstathios; Tassou, Chrysoula

    2012-01-01

    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 sub...

  6. IN VITRO CHARACTERIZATION OF PROBIOTIC PROPERTIES OF LACTIC ACID BACTERIA FROM BULGARIAN RYE SOURDOUGHS

    OpenAIRE

    Dobreva-Yosifova, G.; Yocheva, L.; Mehmed, A.; Danova, S.; Antonova-Nikolova, S.

    2009-01-01

    Lactic acid bacteria play a key role in human health. These friendly bacteria as a part of the microflora of the gastrointestinal tract (GIT) have a beneficial influence on microbial balance. The probiotic cultures stimulate the growth of beneficial microorganisms, crowd out potentially harmful bacteria and reinforce the body's natural defense mechanisms. Recent data improve the positive effects of probiotics and stimulate research for discovering of new lactic acid bacteria strains with prob...

  7. Adhesion of Zearalenone to the Surface of Lactic Acid Bacteria Cells

    OpenAIRE

    Čvek, Domagoj; Markov, Ksenija; Frece, Jadranka; Friganović, Maja; Duraković, Lejla; Delaš, Frane

    2012-01-01

    Zearalenone is mycotoxin harmful to the health of humans and animals and is present in food and feed. Therefore, last few decades, great attention is paid to the development of biological detoxification methods with reference to the application of lactic acid bacteria in binding and removal of mycotoxins from food and feed. The aim of this work was to investigate the ability of lactic acid bacteria Lactobacillus rhamnosus GG (ATCC 53103) and Lactobacillus plantarum A1 to bind zearalenone unto...

  8. SOLID AND LIQUID PINEAPPLE WASTE UTILIZATION FOR LACTIC ACID FERMENTATION USING Lactobacillus delbrueckii

    OpenAIRE

    Abdullah Abdullah

    2012-01-01

    The liquid and solid  pineapple wastes contain mainly sucrose, glucose, fructose and other nutrients. It therefore can potentially be used as carbon source for fermentation to produce organic acid. Recently, lactic acid has been considered to be an important raw material for production of biodegradable lactate polymer. The experiments were  carried out in batch fermentation using  the  liquid and solid pineapple wastes to produce lactic acid. The anaerobic fermentation of ...

  9. ISOLATION OF LACTIC ACID BACTERIA UNDER LOW TEMPERATURE FOR THE PREPARATION OF YOGURT

    OpenAIRE

    Javid Ahmad Bhat; Mohd Irfan Naik; R.K Tenguria

    2014-01-01

    An investigation of isolation of Lactic acid bacteria was carried out under low temperature for the preparation of Yogurt by using various food supplements like carrot, ground-nut and tomato juices. Methods: Various samples of Cow milk, Skimmed milk were processed along with nutrients like Carrot, ground nut and tomato juices with Tryptone glucose yeast extract agar (TGYA) at different temperatures like 50C, 150C and 220C for the isolation of Lactic acid bacteria for the preparation of yogurt...

  10. Thermal characterization of polyhydroxyalkanoates and poly(lactic acid) blends obtained by injection molding

    OpenAIRE

    Loureiro, Nuno Calçada; Ghosh, Satyabrata; Viana, J. C.; Esteves, José Luis

    2015-01-01

    In this work we present the thermal characterization of the full scope of polyhydroxyalcanoate and poly(lactic acid) blends obtain by injection molding. Blends of polyhydroxyalcanoate and poly(lactic acid) (PHA/PLA) were prepared in different compositions ranging from 0–100% in steps of 10%. The blends were injection molded and then characterized by differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and wide angle X-ray diffraction (WAXD). The increment of PHA fractio...

  11. The effect of delignification process with alkaline peroxide on lactic acid production from furfural residues

    OpenAIRE

    Yong Tang; Lingxi Bu; Lihong Deng; Liwei Zhu; Jianxin Jiang

    2012-01-01

    Furfural residues produced from the furfural industry were investigated as a substrate for lactic acid production by simultaneous saccharification and fermentation (SSF). Alkaline peroxide was used for delignification of furfural residues to improve the final lactic acid concentration. The residue was treated with 1.3% to 1.7% hydrogen peroxide at 80 °C for 1 h with a substrate concentration of 3.33%. SSF of furfural residues with different delignification degrees were carried out to eval...

  12. Synthesis and characterization of new biodegradable thermosensitive polyphosphazenes with lactic acid ester and methoxyethoxyethoxy side groups

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Two novel biodegradable thermosensitive polyphosphazenes with lactic acid ester and methoxyethoxyethoxy side groups were synthesized via the macromolecular substitution reactions of poly(dichlorophosphazene) with the sodium salt of lactic acid ester and sodium methoxyethoxyethoxide.Their structures were confirmed by ~(31)p NMR,~1H NMR,~(13)C NMR,IR,DSC,and elemental analysis.The lower critical solution temperature(LCST) behavior in water and in vitro degradation property of the polymers was investigated....

  13. Isolation and characterization of lactic acid bacteria and yeasts from the Brazilian grape sourdough

    OpenAIRE

    Krischina Singer Aplevicz; Jaciara Zarpellon Mazo; Eunice Cassanego Ilha; Andréia Zilio Dinon; Ernani Sebastião Sant´Anna

    2014-01-01

    Sourdough is a mixture of flour and water fermented by lactic acid bacteria and yeast, with a large use in bakery products. This study was developed with Brazilian grape (Niagara rosada) sourdough obtained from spontaneous fermentation. The aim of this work was to characterize genotypic and phenotypically lactic acid bacteria and yeasts isolated from sourdough. The phenotypic identification for bacteria and yeasts was performed by using the kit API50CHL and 20CAUX and the genotypic characteri...

  14. A simple and robust method for pre-wetting poly (lactic-co-glycolic) acid microspheres

    OpenAIRE

    Wright, B; Parmar, N.; Bozec, L.; Aguayo, S. D.; Day, R. M.

    2015-01-01

    Poly (lactic-co-glycolic) acid microspheres are amenable to a number of biomedical procedures that support delivery of cells, drugs, peptides or genes. Hydrophilisation or wetting of poly (lactic-co-glycolic) acid are an important pre-requisites for attachment of cells and can be achieved via exposure to plasma oxygen or nitrogen, surface hydrolysis with NaOH or chloric acid, immersion in ethanol and water, or prolonged incubation in phosphate buffered saline or cell culture medium. The aim o...

  15. Poly(lactic-co-glycolic acid) conduit for repair of injured sciatic nerve: A mechanical analysis

    OpenAIRE

    Yu, Tao; ZHAO, CHANGFU; Li, Peng; Liu, Guangyao; Luo, Min

    2013-01-01

    Tensile stress and tensile strain directly affect the quality of nerve regeneration after bridging nerve defects by poly(lactic-co-glycolic acid) conduit transplantation and autogenous nerve grafting for sciatic nerve injury. This study collected the sciatic nerve from the gluteus maximus muscle from fresh human cadaver, and established 10-mm-long sciatic nerve injury models by removing the ischium, following which poly(lactic-co-glycolic acid) conduits or autogenous nerve grafts were transpl...

  16. Electrochemical L-Lactic Acid Sensor Based on Immobilized ZnO Nanorods with Lactate Oxidase

    OpenAIRE

    Kimleang Khun; Syed Muhammad Usman Ali Shah; Magnus Willander; Zafar Hussain Ibupoto

    2012-01-01

    In this work, fabrication of gold coated glass substrate, growth of ZnO nanorods and potentiometric response of lactic acid are explained. The biosensor was developed by immobilizing the lactate oxidase on the ZnO nanorods in combination with glutaraldehyde as a cross linker for lactate oxidase enzyme. The potentiometric technique was applied for the measuring the output (EMF) response of L-lactic acid biosensor. We noticed that the present biosensor has wide linear detection range of concent...

  17. Nuclear structure at intermediate energies

    Energy Technology Data Exchange (ETDEWEB)

    Bonner, B.E.; Mutchler, G.S.

    1991-09-30

    The theme that unites the sometimes seemingly disparate experiments undertaken by the Bonner Lab Medium Energy Group is a determination to understand in detail the many facets and manifestations of the strong interaction, that which is now referred to as nonperturbative QCD. Whether we are investigating the question of just what does carry the spin of baryons, or the extent of the validity of the SU(6) wavefunctions for the excited hyperons (as will be measured in their radiative decays in our CEBAF experiment), or questions associated with the formation of a new state of matter predicted by QCD (the subject of our BNL experiments E810, E854, as well as our approved experiment at RHIC), -- all these projects share this common goal. Our other experiments represent different approaches to the same broad undertaking. LAMPF E1097 will provide definitive answers to the question of the spin dependence of the inelastic channel of pion production in the n-p interaction. FNAL E683 may well open a new field of investigation in nuclear physics: that of just how quarks and gluons interact with nuclear matter as they transverse nuclei of different sizes. In most all of the experiments mentioned above, the Bonner Lab Group is playing major leadership roles as well as doing a big fraction of the hard work that such experiments require. We use many of the facilities that are unavailable to the intermediate energy physics community and we use our expertise to design and fabricate the detectors and instrumentation that are required to perform the measurements which we decide to do.

  18. Kefir immobilized on corn grains as biocatalyst for lactic acid fermentation and sourdough bread making.

    Science.gov (United States)

    Plessas, Stavros; Alexopoulos, Athanasios; Bekatorou, Argyro; Bezirtzoglou, Eugenia

    2012-12-01

    The natural mixed culture kefir was immobilized on boiled corn grains to produce an efficient biocatalyst for lactic acid fermentation with direct applications in food production, such as sourdough bread making. The immobilized biocatalyst was initially evaluated for its efficiency for lactic acid production by fermentation of cheese whey at various temperatures. The immobilized cells increased the fermentation rate and enhanced lactic acid production compared to free kefir cells. Maximum lactic acid yield (68.8 g/100 g) and lactic acid productivity (12.6 g/L per day) were obtained during fermentation by immobilized cells at 37 °C. The immobilized biocatalyst was then assessed as culture for sourdough bread making. The produced sourdough breads had satisfactory specific loaf volumes and good sensory characteristics. Specifically, bread made by addition of 60% w/w sourdough containing kefir immobilized on corn was more resistant regarding mould spoilage (appearance during the 11(th) day), probably due to higher lactic acid produced (2.86 g/Kg of bread) compared to the control samples. The sourdough breads made with the immobilized biocatalyst had aroma profiles similar to that of the control samples as shown by headspace SPME GC-MS analysis. PMID:23170776

  19. Lactic acid and trisodium phosphate treatment of lamb breast to reduce bacterial contamination.

    Science.gov (United States)

    Ramirez, A J; Acuff, G R; Lucia, L M; Savell, J W

    2001-09-01

    Lactic acid and trisodium phosphate (TSP) were evaluated for the ability to reduce Escherichia coli and aerobic plate counts (APCs) on lamb breasts that were inoculated with a lamb fecal paste. A 90-s water rinse was applied followed by either a 9-s (55 degrees C) 2% lactic acid spray, a 60-s (55 degrees C) 12% TSP dip, or a combined treatment of both lactic acid and TSP treatments. Lactic acid reduced E. coli and APCs by 1.6 log10/cm2, and TSP caused a 1.8-log10/cm2 reduction in E. coli and a 0.7-log10/cm2 reduction in APCs. Combined reductions by the lactic acid spray followed by the TSP dip were 1.8 and 1.5 log10/cm2 for E. coli and APCs, respectively. Lactic acid and trisodium phosphate, used alone or in combination, were effective in reducing numbers of E. coli and could be useful as pathogen intervention steps in lamb slaughter processing. PMID:11563525

  20. Enhancement of L(+)-Lactic Acid Production of Immobilized Rhizopus Oryzae Implanted by Ion Beams

    Institute of Scientific and Technical Information of China (English)

    FAN Yonghong; YANG Yingge; ZHENG Zhiming; LI Wen; WANG Peng; YAO Liming; YU Zengliang

    2008-01-01

    Immobilized Rhizopus oryzae culturing may be a solution to the inhibited production of L(+)-lactic acid in submerged fermentation, which is caused by aggregated mycelia floc. In the present study, a R. Oryzae mutant (RL6041) with a 90% conversion rate of glucose into L-lactic acid was obtained by N+ implantation under the optimized conditions of a beam energy of 15 keV and a dose of 2.6 × 1015 ions/cm2. Using polyurethane foam as the immobilization matrix, the optimal L-lactic acid production conditions were determined as 4 mm polyurethane foam, 150 r/min, 50 g/L ~ 80 g/L of initial glucose, 38~C and pH 6.0. 15-cycle repeated productions of L-lactic acid by immobilized RL6041 were performed under the optimized culturing conditions and over 80% of the glucose was converted into L-lactic acid in 30 hours on average. The results show that immobilized RL6041 is a promising candidate for continuous L-lactic acid production.

  1. Effect of Skimmed-Milk and Starter Addition on Lactic Acid Formation in Soyghurt

    Directory of Open Access Journals (Sweden)

    Yanna Syamsuddin

    2013-01-01

    Full Text Available Research on Effect of Skimmed-Milk and Starter Addition on Lactic Acid Formation in Soyghurt has been done. Soyghurt is a probiotic drinking product made from soy-milk produced by fermentation process using lactic acid bacteria. The bacteria used as starter was Lactobacillus bulgaricus and Streptococcus thermophillus. The objective of this research was to evaluate the effect of skimmed-milk and starter addition on the formation of lactic acid. Variables used in this research was skimmed-milk concentration of 5, 10, and 15% and starter concentration of 3, 5, and 7%, based on volume of soy-milk used as raw material. The soy-milk used was analyzed for its carbohydrate and protein content, and the soyghurt produced was analyzed for its lactic acid, pH and syneresis. The result showed that carbohydrate and protein content in soy-milk was 122.39 mg/L and 2.75%, respectively. The best condition of this process was the addition of 15% skimmed-milk and 5% starter, which yielded the highest lactic acid of 15% with pH of 4.23 and syneresis of 15%. It can be concluded that increasing skimmed-milk concentration cause the increase in lactic acid formation and decrease pH and syneresis. While effect of starter concentration on product analysis was influenced by the amount of nutrition contain in soy-milk.

  2. Liver resection for intermediate hepatocellular carcinoma.

    Science.gov (United States)

    Yi, Peng-Sheng; Zhang, Ming; Zhao, Ji-Tong; Xu, Ming-Qing

    2016-05-18

    Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in China. The Barcelona Clinic Liver Cancer (BCLC) staging system is regarded as the gold standard staging system for HCC, classifying HCC as early, intermediate, or advanced. For intermediate HCC, trans-catheter arterial chemoembolization (TACE) is recommended as the optimal strategy by the BCLC guideline. This review investigates whether liver resection is better than TACE for intermediate HCC. Based on published studies, we compare the survival benefits and complications of liver resection and TACE for intermediate HCC. We also compare the survival benefits of liver resection in early and intermediate HCC. We find that liver resection can achieve better or at least comparable survival outcomes compared with TACE for intermediate HCC; however, we do not observe a significant difference between liver resection and TACE in terms of safety and morbidity. We conclude that liver resection may improve the short- and long-term survival of carefully selected intermediate HCC patients, and the procedure may be safely performed in the management of intermediate HCC. PMID:27190577

  3. Intermediate energy nuclear data for applications

    International Nuclear Information System (INIS)

    A comprehensive review of the data needs for various applications was performed by the participants of the meeting. The status of compilation and evaluation of the needed data in the intermediate energy range of incident particles was discussed. The following broad application areas were identified and considered by the participants: intermediate energy nuclear data needed for accelerators; intermediate energy nuclear data needed for space applications; intermediate energy nuclear data for medical applications. The role of nuclear model calculations in data evaluations in this energy range was considered. The possibilities of existing model codes were considered from the point of view of reliability, accuracy, cost of computer time, availability to specialists in the Member States. The Meeting presentations were divided into the following three sessions: Nuclear data needs in the intermediate energy range (6 papers), Progress of nuclear data computations and evaluations in the intermediate energy range (6 papers) and Progress of experimental data measurements in the intermediate energy range. A separate abstract was prepared for each paper. The ways of further improvement of the status of nuclear data in the intermediate energy range were discussed and the results of these discussions can be found in the conclusions and recommendations of this meeting. Refs, figs and tabs

  4. Gasoline Engine Mechanics. Performance Objectives. Intermediate Course.

    Science.gov (United States)

    Jones, Marion

    Several intermediate performance objectives and corresponding criterion measures are listed for each of six terminal objectives presented in this curriculum guide for an intermediate gasoline engine mechanics course at the secondary level. (For the beginning course guide see CE 010 947.) The materials were developed for a two-semester (2 hour…

  5. Air Conditioning. Performance Objectives. Intermediate Course.

    Science.gov (United States)

    Long, William

    Several intermediate performance objectives and corresponding criterion measures are listed for each of seven terminal objectives for an intermediate air conditioning course. The titles of the seven terminal objectives are Refrigeration Cycle, Job Requirement Skills, Air Conditioning, Trouble Shooting, Performance Test, Shop Management, and S.I.E.…

  6. 39 CFR 3001.39 - Intermediate decisions.

    Science.gov (United States)

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Intermediate decisions. 3001.39 Section 3001.39... Applicability § 3001.39 Intermediate decisions. (a) Initial decision by presiding officer. In any proceedings in... certify and file with the Secretary, a copy of the record of the hearing and his/her initial decision...

  7. Utilization of molasses sugar for lactic acid production by Lactobacillus delbrueckii subsp. delbrueckii mutant Uc-3 in batch fermentation.

    Science.gov (United States)

    Dumbrepatil, Arti; Adsul, Mukund; Chaudhari, Shivani; Khire, Jayant; Gokhale, Digambar

    2008-01-01

    Efficient lactic acid production from cane sugar molasses by Lactobacillus delbrueckii mutant Uc-3 in batch fermentation process is demonstrated. Lactic acid fermentation using molasses was not significantly affected by yeast extract concentrations. The final lactic acid concentration increased with increases of molasses sugar concentrations up to 190 g/liter. The maximum lactic acid concentration of 166 g/liter was obtained at a molasses sugar concentration of 190 g/liter with a productivity of 4.15 g/liter/h. Such a high concentration of lactic acid with high productivity from molasses has not been reported previously, and hence mutant Uc-3 could be a potential candidate for economical production of lactic acid from molasses at a commercial scale. PMID:17981933

  8. STUDY OF THE EFFECTS SHOWN BY THE ACTION OF VARIOUS MICROORGANISMS ON THE LACTIC FERMENTATION OF JUICES

    OpenAIRE

    Iuliana Manea; Lavinia Buruleanu

    2010-01-01

    Research has established the most effective lactic acid bacteria used for fermentation of fruit and vegetables juices. The cultures were used for Bifidobacteria, Lactobacillus acidophilus and culture of micro flora obtained spontaneous shoots. Lactic fermented juice was obtained from cabbage, carrots and beetroot. Working in these variants were determined lactic fermentation parameters and some of the bioactive compounds from this process: pH, reducing sugars, viable cell counts. Determinatio...

  9. The use of date waste for lactic acid production by a fed-batch culture using Lactobacillus casei subsp. rhamnosus

    OpenAIRE

    Aicha Nancib; Nabil Nancib; Abdelhafid Boubendir; Joseph Boudrant

    2015-01-01

    The production of lactic acid from date juice by Lactobacillus caseisubsp. rhamnosus in batch and fed-batch cultures has been investigated. The fed-batch culture system gave better results for lactic acid production and volumetric productivity. The aim of this work is to determine the effects of the feeding rate and the concentration of the feeding medium containing date juice glucose on the cell growth, the consumption of glucose and the lactic acid production by Lactobacillus casei subsp. r...

  10. A platform technology of recovery of lactic acid from a fermentation broth of novel substrate Zizyphus oenophlia

    OpenAIRE

    Bishai, Moumita; De, Swarnalok; Adhikari, Basudam; Banerjee, Rintu

    2014-01-01

    Lactic acid, a biologically derived compound, exists ubiquitously in nature. Its existence ranges from human being to microorganisms. Having paramount industrial significance, lactic acid should be highly pure, devoid of any contaminants. Hence, development of minimum steps of platform technologies to purify it needs urgent attention. The article proposed a novel and simple process for separation of lactic acid from a potential substrate Zizyphus oenophlia, based on ion exchange chromatograph...

  11. Poly(dopamine) coating of 3D printed poly(lactic acid) scaffolds for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Kao, Chia-Tze [School of Dentistry, Chung Shan Medical University, Taichung City, Taiwan (China); Department of Stomatology, Chung Shan Medical University Hospital, Taichung City, Taiwan (China); Lin, Chi-Chang [Department of Chemical and Materials Engineering, Tunghai University, Taichung City, Taiwan (China); Chen, Yi-Wen; Yeh, Chia-Hung [3D Printing Medical Research Center, China Medical University Hospital, Taichung City, Taiwan (China); Fang, Hsin-Yuan [3D Printing Medical Research Center, China Medical University Hospital, Taichung City, Taiwan (China); Department of Thoracic Surgery, China Medical University Hospital, Taichung City, Taiwan (China); School of Medicine, College of Medicine, College of Public Health, Taichung City, Taiwan (China); Shie, Ming-You, E-mail: eviltacasi@gmail.com [3D Printing Medical Research Center, China Medical University Hospital, Taichung City, Taiwan (China)

    2015-11-01

    3D printing is a versatile technique to generate large quantities of a wide variety of shapes and sizes of polymer. The aim of this study is to develop functionalized 3D printed poly(lactic acid) (PLA) scaffolds and use a mussel-inspired surface coating to regulate cell adhesion, proliferation and differentiation of human adipose-derived stem cells (hADSCs). We prepared PLA 3D scaffolds coated with polydopamine (PDA). The chemical composition and surface properties of PDA/PLA were characterized by XPS. PDA/PLA modulated hADSCs' responses in several ways. Firstly, adhesion and proliferation, and cell cycle of hADSCs cultured on PDA/PLA were significantly enhanced relative to those on PLA. In addition, the collagen I secreted from cells was increased and promoted cell attachment and cell cycle progression were depended on the PDA content. In osteogenesis assay, the ALP activity and osteocalcin of hADSCs cultured on PDA/PLA were significantly higher than seen in those cultured on pure PLA scaffolds. Moreover, hADSCs cultured on PDA/PLA showed up-regulation of the ang-1 and vWF proteins associated with angiogenic differentiation. Our results demonstrate that the bio-inspired coating synthetic PLA polymer can be used as a simple technique to render the surfaces of synthetic scaffolds active, thus enabling them to direct the specific responses of hADSCs. - Highlights: • A simple method of 3D printed poly(lactic acid) scaffold coated with PDA • Promoted proliferation of hADSCs on PDA/PLA scaffolds • Increased collagen I, cell cycle, and cell adhesion with a high PDA content • Up-regulation of angiogenic and osteogenic of hADSCs • A promising method for bioinspired surface modification on PLA using PDA.

  12. Poly(dopamine) coating of 3D printed poly(lactic acid) scaffolds for bone tissue engineering

    International Nuclear Information System (INIS)

    3D printing is a versatile technique to generate large quantities of a wide variety of shapes and sizes of polymer. The aim of this study is to develop functionalized 3D printed poly(lactic acid) (PLA) scaffolds and use a mussel-inspired surface coating to regulate cell adhesion, proliferation and differentiation of human adipose-derived stem cells (hADSCs). We prepared PLA 3D scaffolds coated with polydopamine (PDA). The chemical composition and surface properties of PDA/PLA were characterized by XPS. PDA/PLA modulated hADSCs' responses in several ways. Firstly, adhesion and proliferation, and cell cycle of hADSCs cultured on PDA/PLA were significantly enhanced relative to those on PLA. In addition, the collagen I secreted from cells was increased and promoted cell attachment and cell cycle progression were depended on the PDA content. In osteogenesis assay, the ALP activity and osteocalcin of hADSCs cultured on PDA/PLA were significantly higher than seen in those cultured on pure PLA scaffolds. Moreover, hADSCs cultured on PDA/PLA showed up-regulation of the ang-1 and vWF proteins associated with angiogenic differentiation. Our results demonstrate that the bio-inspired coating synthetic PLA polymer can be used as a simple technique to render the surfaces of synthetic scaffolds active, thus enabling them to direct the specific responses of hADSCs. - Highlights: • A simple method of 3D printed poly(lactic acid) scaffold coated with PDA • Promoted proliferation of hADSCs on PDA/PLA scaffolds • Increased collagen I, cell cycle, and cell adhesion with a high PDA content • Up-regulation of angiogenic and osteogenic of hADSCs • A promising method for bioinspired surface modification on PLA using PDA

  13. Poly(l-lactic acid)-modified silica stationary phase for reversed-phase and hydrophilic interaction liquid chromatography

    OpenAIRE

    Ohyama, Kaname; Takasago, Shizuka; Kishikawa, Naoya; Kuroda, Naotaka

    2015-01-01

    Poly(L-lactic acid) is a linear aliphatic thermoplastic polyester that can be produced from renewable resources. A poly(L-lactic acid)-modified silica stationary phase was newly prepared by amide bond reaction between amino groups on aminopropyl silica and carboxylic acid groups at the end of the poly(L-lactic acid) chain. The poly(L-lactic acid)-silica column was characterized in reversed-phase liquid chromatography and hydrophilic interaction liquid chromatography with the use of different ...

  14. The Optimized Synthesis of Starch-g-Lactic Acid Copolymer with High Grafting Degree Catalyzed by Sulfuric Acid

    Institute of Scientific and Technical Information of China (English)

    HU Zhiying

    2014-01-01

    The starch-g-lactic acid copolymer was synthesized with catalysis of sulfuric acid by one-step process, and the structure of starch-g-lactic acid copolymer was characterized by means of IR, 13C-NMR, HMBC, XRD, and SEM. The experimental results show that the maximum grafting degree of starch can reach 75%when the starch-g-lactic acid copolymer is activated at 80℃for 2 h and reacted with lactic acid at 90℃for 4 h in vacuum.

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

    Science.gov (United States)

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

    2016-08-01

    During the last years the interest in donkey milk has increased significantly mainly because of its compelling functional elements. Even if the composition and nutritional properties of donkey milk are known, its microbiota is less studied. This Research Communication aimed to provide a comprehensive characterisation of the lactic acid bacteria in raw donkey milk. RAPD-PCR assay combined with 16S rDNA sequencing analysis were used to describe the microbial diversity of several donkey farms in the North West part of Italy. The more frequently detected species were: Lactobacillus paracasei, Lactococcus lactis and Carnobacterium maltaromaticum. Less abundant genera were Leuconostoc, Enterococcus and Streptococcus. The yeast Kluyveromyces marxianus was also isolated. The bacterial and biotype distribution notably diverged among the farms. Several of the found species, not previously detected in donkey milk, could have an important probiotic activity and biotechnological potential. This study represents an important insight to the ample diversity of the microorganisms present in the highly selective ecosystem of raw donkey milk. PMID:27600975

  16. Lactic acid bacterial extract as a biogenic mineral growth modifier

    Science.gov (United States)

    Borah, Ballav M.; Singh, Atul K.; Ramesh, Aiyagari; Das, Gopal

    2009-04-01

    The formation of minerals and mechanisms by which bacteria could control their formation in natural habitats is now of current interest for material scientists to have an insight of the mechanism of in vivo mineralization, as well as to seek industrial and technological applications. Crystalline uniform structures of calcium and barium minerals formed micron-sized building blocks when synthesized in the presence of an organic matrix consisting of secreted protein extracts from three different lactic acid bacteria (LAB) viz.: Lactobacillus plantarum MTCC 1325, Lactobacillus acidophilus NRRL B4495 and Pediococcus acidilactici CFR K7. LABs are not known to form organic matrix in biological materialization processes. The influence of these bacterial extracts on the crystallization behavior was investigated in details to test the basic coordination behavior of the acidic protein. In this report, varied architecture of the mineral crystals obtained in presence of high molecular weight protein extracts of three different LAB strains has been discussed. The role of native form of high molecular weight bacterial protein extracts in the generation of nucleation centers for crystal growth was clearly established. A model for the formation of organic matrix-cation complex and the subsequent events leading to crystal growth is proposed.

  17. Effect of Lactic Acid Bacterial Inoculants on Rice Straw Silage

    Institute of Scientific and Technical Information of China (English)

    HUA Jinling; ZHANG Yonggen; MEN Yuxin

    2008-01-01

    The trail was designed to study on technique aspects of ensiling rice straw (RS) appended amounts of lactobacillus.There were two groups according to silage ways, baled silage (BS) and chopped silage (CS), in which lactobacillus was added at levels of 10,15 and 20 mg·kg-1,respectively and the mixtures were placed into a packed polyethylene bags and stored at room temperature for 45 days.The results showed that lactobacillus had remarkable effect on fermentation characteristics of RS. The quality of the silage was improved with the lactobacillus addition.In the experiment the optimal quality of rice straw silage (RSS) can be obtained when lactobacillus was added with 15 or 20 mg·kg-1 level.The effect of different silage methods was very remarkable to the silage quality of same material.The quality of CS was better than that of long silage, at the same time,BS was feasible on condition of eligible level of lactic acid bacteria.

  18. Blends of Poly (lactic acid) with Thermoplastic Acetylated Starch

    Institute of Scientific and Technical Information of China (English)

    ZHANG Kun-yu; RAN Xiang-hai; ZHUANG Yu-gang; YAO Bin; DONG Li-song

    2009-01-01

    Blends of poly(lactic acid)(PLA) and thermoplastic acetylated starch(ATPS) were prepared by means of the melt mixing method. The results show that PLA and ATPS were partially miscible, which was confirmed with the measurement of T_g by dynamic mechanical analysis(DMA) and differrential scanning calorimetry(DSC). The mechanical and thermal properties of the blends were improved. With increasing the ATPS content, the elongation at break and impact strength were increased. The elongation at break increased from 5% of neat PLA to 25% of the blend PLA/ATPS40. It was found that the cold crystallization behavior of PLA changed evidently by addition of ATPS. The cold crystallization temperature(T_(cc)) of each of PLA/ATPS blends was found to shift to a lower temperature and the width of exothermic peak became narrow compared with that of neat PLA. The thermogravimetry analy-sis(TGA) results showed that the peak of derivative weight for ATPS moved to higher temperature with increasing PLA content in PLA/ATPS blends. It can be concluded that PLA could increase the thermal stability of ATPS. The rheological measurement reveals the melt elasticity and viscosity of the blends decreased with the increased concentration of ATPS, which was favorable to the processing properties of PLA.

  19. Antimicrobial susceptibility of lactic acid bacteria isolated from Sombor cheese

    Directory of Open Access Journals (Sweden)

    Bulajić Snežana

    2011-01-01

    Full Text Available Extensive literature data pointed out that some lactic acid bacteria (LABs, the predominant microbiota in fermented dairy products, may serve as reservoirs of antibiotic resistance genes potentially transferable to human pathogens. Hence, there is a growing interest in the possible role of Las vectors of antibiotic resistance determinants. This paper reports the susceptibility patterns of a number of Lspecies (belonging to the genera Lactococcus, Lactobacillus, and Enterococcus isolated from different batches of autochthonous Sombor cheese, traditionally made without the addition of starter cultures, and currently proposed as a candidate for PDO/PGI designation. The experimental work was performed to select strains that do not contain antibiotic resistance genes among those with desirable technological characteristics such as rapid acidification, proteolysis, ability to metabolise citrate and form aromogenic compounds. In addition, the results of these screening procedures could also indicate the types and degrees of antimicrobial resistance already present among the Lcommunity of Sombor cheese, which according to their geographically restricted areas of production, specific manufacturing process and characteristic aroma and appearance, represent a distinct ecological niche.

  20. Antibiotic resistance in food lactic acid bacteria--a review.

    Science.gov (United States)

    Mathur, Shalini; Singh, Rameshwar

    2005-12-15

    Antibiotics are a major tool utilized by the health care industry to fight bacterial infections; however, bacteria are highly adaptable creatures and are capable of developing resistance to antibiotics. Consequently, decades of antibiotic use, or rather misuse, have resulted in bacterial resistance to many modern antibiotics. This antibiotic resistance can cause significant danger and suffering for many people with common bacterial infections, those once easily treated with antibiotics. For several decades studies on selection and dissemination of antibiotic resistance have focused mainly on clinically relevant species. However, recently many investigators have speculated that commensal bacteria including lactic acid bacteria (LAB) may act as reservoirs of antibiotic resistance genes similar to those found in human pathogens. The main threat associated with these bacteria is that they can transfer resistance genes to pathogenic bacteria. Genes conferring resistance to tetracycline, erythromycin and vancomycin have been detected and characterized in Lactococcus lactis, Enterococci and, recently, in Lactobacillus species isolated from fermented meat and milk products. A number of initiatives have been recently launched by various organizations across the globe to address the biosafety concerns of starter cultures and probiotic microorganisms. The studies can lead to better understanding of the role played by the dairy starter microorganisms in horizontal transfer of antibiotic resistance genes to intestinal microorganisms and food-associated pathogenic bacteria. PMID:16289406

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

    Directory of Open Access Journals (Sweden)

    Nengah Sujaya

    2008-06-01

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

  2. Diversity of lactic acid bacteria of the bioethanol process

    Directory of Open Access Journals (Sweden)

    Azevedo Vasco

    2010-11-01

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

  3. Co-culture-inducible bacteriocin production in lactic acid bacteria.

    Science.gov (United States)

    Chanos, Panagiotis; Mygind, Tina

    2016-05-01

    It is common knowledge that microorganisms have capabilities, like the production of antimicrobial compounds, which do not normally appear in ideal laboratory conditions. Common antimicrobial discovery techniques require the isolation of monocultures and their individual screening against target microorganisms. One strategy to achieve expression of otherwise hidden antimicrobials is induction by co-cultures. In the area of bacteriocin-producing lactic acid bacteria, there has been some research focusing into the characteristics of co-culture-inducible bacteriocin production and particularly the molecular mechanism(s) of such interactions. No clear relationship has been seen between bacteriocin-inducing and bacteriocin-producing microorganisms. The three-component regulatory system seems to be playing a central role in the induction, but inducing compounds have not been identified or characterized. However, the presence of the universal messenger molecule autoinducer-2 has been associated in some cases with the co-culture-inducible bacteriocin phenotype and it may play the role in the additional regulation of the three-component regulatory system. Understanding the mechanisms of induction would facilitate the development of strategies for screening and development of co-culture bacteriocin-producing systems and novel products as well as the perseverance of such systems in food and down to the intestinal tract, possibly conferring a probiotic effect on the host. PMID:27037694

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

    Directory of Open Access Journals (Sweden)

    Mari Vasama

    2014-07-01

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

  5. Biodegradation of flax fiber reinforced poly lactic acid

    Directory of Open Access Journals (Sweden)

    2010-07-01

    Full Text Available Woven and nonwoven flax fiber reinforced poly lactic acid (PLA biocomposites were prepared with amphiphilic additives as accelerator for biodegradation. The prepared composites were buried in farmland soil for biodegradability studies. Loss in weight of the biodegraded composite samples was determined at different time intervals. The surface morphology of the biodegraded composites was studied with scanning electron microscope (SEM. Results indicated that in presence of mandelic acid, the composites showed accelerated biodegradation with 20–25% loss in weight after 50–60 days. On the other hand, in presence of dicumyl peroxide (as additive, biodegradation of the composites was relatively slow as confirmed by only 5–10% loss in weight even after 80–90 days. This was further confirmed by surface morphology of the biodegraded composites. We have attempted to show that depending on the end uses, we can add different amphiphilic additives for delayed or accelerated biodegradability. This work gives us the idea of biodegradation of materials from natural fiber reinforced PLA composites when discarded carelessly in the environment instead of proper waste disposal site.

  6. Antibiotics influence on lactic acid bacteria inhibiting gastrointestinal tract

    Directory of Open Access Journals (Sweden)

    Andreja Čanžek Majhenič

    2001-04-01

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

  7. Fracture behavior of quenched poly(lactic acid

    Directory of Open Access Journals (Sweden)

    2011-01-01

    Full Text Available The effect of a quenching treatment applied on heated cast sheet extruded films of two poly(lactic acid (PLA commercial grades, with different optical purities, was studied. The thermal and mechanical properties of the films, as well as their fracture behavior, were assessed by differential scanning calorimetry (DSC, tensile tests, and the essential work of fracture (EWF approach. The heating-quenching treatment causes a de-aging effect with an increase in the free volume of polymer chains evidenced by a decrease in the glass transition temperature (Tg and a decrease in the tensile stiffness and yield stress. As a result, there is an abrupt increase in ductility, finding a dramatic change in the fracture behavior, from brittle to ductile. The use of digital image correlation (DIC of the strain field analysis during fracture testing has allowed relating the decrease on the yield stress promoted by quenching with the crack propagation kinetics. The use of the EWF method to characterize the fracture toughness of PLA has allowed to measure this enhancement on toughness, finding that the specific essential work of fracture (we and the plastic term (βwp parameters increased 120% and 1200%, respectively, after the quenching process.

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

    Science.gov (United States)

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

    2016-01-01

    Beer contains only limited amounts of readily fermentable carbohydrates and amino acids. Beer spoilage lactic acid bacteria (LAB) have to come up with metabolic strategies in order to deal with selective nutrient content, high energy demand of hop tolerance mechanisms and a low pH. The metabolism of 26 LAB strains of 6 species and varying spoilage potentialwas investigated in order to define and compare their metabolic capabilities using multivariate statistics and outline possible metabolic strategies. Metabolic capabilities of beer spoilage LAB regarding carbohydrate and amino acids did not correlate with spoilage potential, but with fermentation type (heterofermentative/homofermentative) and species. A shift to mixed acid fermentation by homofermentative (hof) Pediococcus claussenii and Lactobacillus backii was observed as a specific feature of their growth in beer. For heterofermentative (hef) LAB a mostly versatile carbohydrate metabolism could be demonstrated, supplementing the known relevance of organic acids for their growth in beer. For hef LAB a distinct amino acid metabolism, resulting in biogenic amine production, was observed, presumably contributing to energy supply and pH homeostasis. PMID:26398285

  9. Poly (lactic acid) (PLA)/clay/wood nanocomposites

    Science.gov (United States)

    Meng, Qingkai

    Poly (lactic acid) (PLA) is a promising substitute for conventional petroleum-based polymer materials as a result of its environmentally benign quality and suitable physical properties. However, there are also problems associated with properties, such as brittleness, low heat deflection temperature, low melt viscosity, as well as cost that prevent wide-range applications of PLA. This work reports on melt extrusion preparation of PLA/clay/wood nanocomposites involving various compatibilizers, resulting in remarkable improvements in mechanical as well as in thermal material properties. In particular, the tensile and flexural moduli of PLA/clay/wood nanocomposites with 30 wt. % wood flour and 5 wt. % nanoclay respectively increased from 3.75 to 7.08 GPa and from 3.83 to 6.01 GPa compared to neat PLA. The thermal decomposition temperature improved by about 10°C compared to that of PLA/wood composites. A mathematical model was developed based on Eshelby's equivalent inclusion method and Mori-Tanaka's background analysis to successfully predict longitudinal elastic moduli of complex structured nanocomposite materials.

  10. Pyruvate carboxylase deficiency: An underestimated cause of lactic acidosis

    Directory of Open Access Journals (Sweden)

    F. Habarou

    2015-03-01

    Full Text Available Pyruvate carboxylase (PC is a biotin-containing mitochondrial enzyme that catalyzes the conversion of pyruvate to oxaloacetate, thereby being involved in gluconeogenesis and in energy production through replenishment of the tricarboxylic acid (TCA cycle with oxaloacetate. PC deficiency is a very rare metabolic disorder. We report on a new patient affected by the moderate form (the American type A. Diagnosis was nearly fortuitous, resulting from the revision of an initial diagnosis of mitochondrial complex IV (C IV defect. The patient presented with severe lactic acidosis and pronounced ketonuria, associated with lethargy at age 23 months. Intellectual disability was noted at this time. Amino acids in plasma and organic acids in urine did not show patterns of interest for the diagnostic work-up. In skin fibroblasts PC showed no detectable activity whereas biotinidase activity was normal. We had previously reported another patient with the severe form of PC deficiency and we show that she also had secondary C IV deficiency in fibroblasts. Different anaplerotic treatments in vivo and in vitro were tested using fibroblasts of both patients with 2 different types of PC deficiency, type A (patient 1 and type B (patient 2. Neither clinical nor biological effects in vivo and in vitro were observed using citrate, aspartate, oxoglutarate and bezafibrate. In conclusion, this case report suggests that the moderate form of PC deficiency may be underdiagnosed and illustrates the challenges raised by energetic disorders in terms of diagnostic work-up and therapeutical strategy even in a moderate form.

  11. Poly (lactic acid organoclay nano composites for paper coating applications

    Directory of Open Access Journals (Sweden)

    Tatcha Sonjui

    2014-10-01

    Full Text Available Poly(lactic acid or PLA is a well-known biodegradable polymer derived from renewable resources such as corn strach, tapioca strach, and sugar cane. PLA is the most extensively utilized biodegradable polyester with potential to replace conventional petrochemical-based polymers. However, PLA has some drawbacks, such as brittleness and poor gas barrier properties. Nano composite polymers have experience and increasing interest due to their characteristics, especially in mechanical and thermal properties. The objectives of this research were to prepare PLA formulations using three different PLAs. The formulas giving high gloss coating film were selected to prepare nano composite film by incorporated with different amount of various types of organoclays. The physical properties of the PLA coating films were studied and it was found that the PLA 7000D with 0.1%w/w of Cloisite 30B provided decent viscosity for coating process. In addition, the nano composite coating films showed good physical properties such as high gloss, good adhesion, and good hardness. There is a possibility of using the obtained formulation as a paper coating film.

  12. The Effects of Lactic Acid Bacteria and Lactic Acid Bacteria+Enzyme Mixture Silage Inoculants on Maize Silage Fermentation and Nutrient Digestibility in Lambs

    Directory of Open Access Journals (Sweden)

    M. L. Ozduven

    2005-01-01

    Full Text Available This study was carried out to determine the effects of lactic acid bacteria and lact ic acidbacteria+enzyme mixture inoculants as silage additives, on the fermentation, aerobic stability, cell wallcontent, and nutrient digestibility in lambs of maize silages. Pioneer 1174 (Iowa, USA, and Maize -All(Alltech, UK were used as lactic acid bacteria and lactic acid bacteria+enzyme mixture inoculants. Plantmaterials were fermented for 60 days in bunker type silos. Aerobic stability test was applied to all silosopened in the end of fermentation period. Relating to silage fermentation analysis of pH, ammonia nitrogen,water soluble carbohydrate, organic acids (lactic, acetic and butyric acid were carried out andmicrobiological analyses had been done. Digestional value of crude nutritive matters of silages determinedwith classical digestive experiments. Both inoculants increased characteristics of fermentation but impairedaerobic stability of maize silages. Inoculants were not effect on the nutritient digestibility of silages. Lacticacid bacteria+enzyme mixture inoculant decreased neutral and acid detergent fiber content.

  13. Phenotypic and genotypic characterization of lactic acid bacteria isolated from raw goat milk and effect of farming practices on the dominant species of lactic acid bacteria.

    Science.gov (United States)

    Tormo, Hélène; Ali Haimoud Lekhal, Djamila; Roques, C

    2015-10-01

    Lactic acid bacteria, in particular Lactococcus lactis, play a decisive role in the cheese making process and more particularly in lactic cheeses which are primarily produced on goat dairy farms. The objective of this study was therefore to identify the main lactic acid bacteria found in raw goats' milk from three different regions in France and evaluate if certain farming practices have an effect on the distribution of species of lactic acid bacteria in the various milk samples. Identification at genus or species level was carried out using phenotypic tests and genotypic methods including repetitive element REP-PCR, species-specific PCR and 16S rRNA gene sequencing. The distribution of the main bacterial species in the milk samples varied depending on farms and their characteristics. Out of the 146 strains identified, L. lactis was the dominant species (60% of strains), followed by Enterococcus (38%) of which Enterococcus faecalis and Enterococcus faecium. Within the species L. lactis, L. lactis subsp lactis was detected more frequently than L. lactis subsp cremoris (74% vs. 26%). The predominance of L. lactis subsp cremoris was linked to geographical area studied. It appears that the animals' environment plays a role in the balance between the dominance of L. lactis and enterococci in raw goats' milk. The separation between the milking parlor and the goat shed (vs no separation) and only straw in the bedding (vs straw and hay) seems to promote L. lactis in the milk (vs enterococci). PMID:26082325

  14. Intermedial Strategies of Memory in Contemporary Novels

    DEFF Research Database (Denmark)

    Tanderup, Sara

    2014-01-01

    Judd Morrissey and drawing on the theoretical perspectives of N. Katherine Hayles (media studies) and Andreas Huyssen (cultural memory studies), Tanderup argues that recent intermedial novels reflect a certain nostalgia celebrating and remembering the book as a visual and material object in the age of......In her article "Intermedial Strategies and Memory in Contemporary Novels" Sara Tanderup discusses a tendency in contemporary literature towards combining intermedial experiments with a thematic preoccupation with memory and trauma. Analyzing selected works by Steven Hall, Jonathan Safran Foer, and...... digital media while also highlighting the influence of new media on our cultural understanding and representation of memory and the past....

  15. Chemical substructure analysis in toxicology

    International Nuclear Information System (INIS)

    A preliminary examination of chemical-substructure analysis (CSA) demonstrates the effective use of the Chemical Abstracts compound connectivity file in conjunction with the bibliographic file for relating chemical structures to biological activity. The importance of considering the role of metabolic intermediates under a variety of conditions is illustrated, suggesting structures that should be examined that may exhibit potential activity. This CSA technique, which utilizes existing large files accessible with online personal computers, is recommended for use as another tool in examining chemicals in drugs. 2 refs., 4 figs

  16. Chemical substructure analysis in toxicology

    Energy Technology Data Exchange (ETDEWEB)

    Beauchamp, R.O. Jr. [Center for Information on Toxicology and Environment, Raleigh, NC (United States)

    1990-12-31

    A preliminary examination of chemical-substructure analysis (CSA) demonstrates the effective use of the Chemical Abstracts compound connectivity file in conjunction with the bibliographic file for relating chemical structures to biological activity. The importance of considering the role of metabolic intermediates under a variety of conditions is illustrated, suggesting structures that should be examined that may exhibit potential activity. This CSA technique, which utilizes existing large files accessible with online personal computers, is recommended for use as another tool in examining chemicals in drugs. 2 refs., 4 figs.

  17. Bacteriocins from lactic acid bacteria: purification, properties and use as biopreservatives

    Directory of Open Access Journals (Sweden)

    José Luis Parada

    2007-05-01

    Full Text Available Biopreservation systems in foods are of increasing interest for industry and consumers. Bacteriocinogenic lactic acid bacteria and/or their isolated bacteriocins are considered safe additives (GRAS, useful to control the frequent development of pathogens and spoiling microorganisms in foods and feed. The spreading of bacterial antibiotic resistance and the demand for products with fewer chemicals create the necessity of exploring new alternatives, in order to reduce the abusive use of therapeutic antibiotics. In this context, bacteriocins are indicated to prevent the growth of undesirable bacteria in a food-grade and more natural way, which is convenient for health and accepted by the community. According to their properties, structure, molecular weight (MW, and antimicrobial spectrum, bacteriocins are classified in three different groups: lantibiotics and non-lantibiotics of low MW, and those of higher MW. Several strategies for isolation and purification of bacteriocins from complex cultivation broths to final products were described. Biotechnological procedures including salting-out, solvent extraction, ultrafiltration, adsorption-desortion, ion-exchange, and size exclusion chromatography are among the most usual methods. Peptide structure-function studies of bacteriocins and bacterial genetic advances will help to understand the molecular basis of their specificity and mode of action. Nisin is a good example of commercial success, and a good perspective is open to continue the study and development of new bacteriocins and their biotechnological applications. These substances in appropriate concentrations may be used in veterinary medicine and as animal growth promoter instead usual antibiotics, as well as an additional hurdle factor for increasing the shelf life of minimal processed foods.

  18. Bioplastic composite foam prepared from poly(lactic acid) and natural wood flour

    Science.gov (United States)

    Suwannakas, Pokkes; Petrchwattana, Nawadon; Covavisaruch, Sirijutaratana

    2016-03-01

    The major drawbacks of Poly(lactic acid) (PLA) bioplastic are its cost and brittleness. This study aims to reduce the cost by foaming PLA reinforced with wood flour. A series of PLA/ natural fiber (WF) composite was prepared by using WF of selected conifers up to 5 wt%; each composite formulation was then foamed using 2 wt% of Azodicarbonamide (ADC) as chemical foaming agent. ADC effectively reduced the density of PLA and the PLA/WF composite foam by about 45% to 0.64 g/cm3 from 1.24 g/cm3 of neat PLA and 1.26 g/cm3 of PLA/WF composites when 2 wt% ADC was applied. Mechanical behaviors in terms of compressive and impact properties were investigated. With the presence of WF, the compressive stress increased with the WF content due to the good interfacial adhesion between the PLA matrix and the WF. This was verified by microscopic observation, leading to efficient stress transfer at the interface between PLA matrix and the WF. The presence of WF raised the specific compressive modulus and strength of PLA/WF composites to around 0.94 GPa.cm3/g and 2.65 MPa.cm3/g but foaming the PLA or the PLA/WF composites led to a dramatic reduction of the compressive modulus to 0.2-0.4 GPa.cm3/g, implying that the PLA and the PLA/WF foams had become softened. This was evidently observed in the significant reduction of hardness coupled with the vast drop of stress required to compressively deform the foams.

  19. Intermediate/Advanced Research Design and Statistics

    Science.gov (United States)

    Ploutz-Snyder, Robert

    2009-01-01

    The purpose of this module is To provide Institutional Researchers (IRs) with an understanding of the principles of advanced research design and the intermediate/advanced statistical procedures consistent with such designs

  20. Bursts of intermediate ions in atmospheric air

    Science.gov (United States)

    Hõrrak, U.; Salm, J.; Tammet, H.

    1998-06-01

    The mobility spectrum of air ions has been measured at Tahkuse Observatory in Estonia for several years. The average concentration of intermediate ions with mobilities of 0.05-0.5 cm2 V-1 s-1 in atmospheric air is about 50 cm-3. On the level of this low background, high concentration bursts of intermediate air ions occur occasionally. A burst can be followed by subsequent evolution of intermediate ions into larger ones. To explain the bursts of intermediate air ions, two hypotheses can be advanced: (1)A burst of neutral particles occurs due to homogeneous nucleation, and the particles are charged by the attachment of cluster ions. (2) The cluster ions grow by ion-induced nucleation in proper environmental conditions.