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Sample records for bacteria lysis processes

  1. Study of the phage production efficiency in the bacteria lysis processes

    In this work we present a search for the best production conditions of λvir andλ clear phages In E coli K12 and E coli C600 infected cells respectively. By keeping fixed some parameters of the process as the bacterial and phage generation times and (he bacterial burst side, we have finder that the lysis yield is strongly dependent on the multiplicity and in a lesser degree on the infection time. It appears from the experimental results that other variables are important, as infection efficiency and approach time from phages to bacteria. We will try to describe the lysis phenomenon by a numerical model on the bases of the se experimental results. (Author) 11 refs

  2. Study of the phage production efficiency in the bacteria lysis processes; Estudio del rendimiento en fagos para los procesos de lisis bacteriana

    Vidania Munoz, R. de; Garces, F.; Davila, C. A.

    1979-07-01

    In this work we present a search for the best production conditions of {lambda}vir and{lambda} clear phages In E coli K12 and E coli C{sub 6}00 infected cells respectively. By keeping fixed some parameters of the process as the bacterial and phage generation times and the bacterial burst side, we have found that the lysis yield is strongly dependent on the multiplicity and in a lesser degree on the infection time. It appears from the experimental results that other variables are important, as infection efficiency and approach time from phages to bacteria. We will try to describe the lysis phenomenon by a numerical model on the bases of the se experimental results. (Author) 11 refs.

  3. Cell lysis and superoxide dismutase activities of highly radioresistant bacteria

    The highly radioresistant bacterium, Arthrobacter radiotolerans, has been isolated from the radioactive hot spring of Misasa, and it does not sporulate, it is Gram-positive, and its color is pink to red. This bacterium shows the highest resistance to gamma-ray among Gram-positive resistants, but the lytic enzyme capable of lysing the cells of strong radioresistants and the surface structure of the cells are little known except those about Micrococcus radiodurans. The cells of the M. radiodurans can be lysed by Achramobacter lyticus enzyme, and electron microscopic observation and chemical analysis revealed the mutilayered surface structure of the cells consisting of an inner membrane, a mucopeptide wall layer and a very outer layer. The superoxide dismutase (SOD) activity of aerobic and anaerobic bacteria was studied, and the relatively high SOD activity of the M. radiodurans was found. The SOD function acts against the threat posed by the reactive superoxide radical being generated biologically, photochemically and radiochemically in the presence of molecular oxygen. In this paper, it is reported that the lytic enzyme No.2 obtained from Cytophaga sp., containing N-acetyl-muramyl-L-alanine amidase, peptidase and endopeptidase, and showing broad lytic spectra, was able to lyse the cells of A. radiotolerans and four radioresistant micrococci, and the radioresistant bacteria showed relatively high SOD activity except M. sp. 248. It is well known that superoxide anions are generated by aerobic irradiation, and are toxic to microbial cells. (Kako, I.)

  4. Performance Evaluation of Fast Microfluidic Thermal Lysis of Bacteria for Diagnostic Sample Preparation

    Evangelyn C. Alocilja

    2013-01-01

    Full Text Available Development of new diagnostic platforms that incorporate lab-on-a-chip technologies for portable assays is driving the need for rapid, simple, low cost methods to prepare samples for downstream processing or detection. An important component of the sample preparation process is cell lysis. In this work, a simple microfluidic thermal lysis device is used to quickly release intracellular nucleic acids and proteins without the need for additional reagents or beads used in traditional chemical or mechanical methods (e.g., chaotropic salts or bead beating. On-chip lysis is demonstrated in a multi-turn serpentine microchannel with external temperature control via an attached resistive heater. Lysis was confirmed for Escherichia coli by fluorescent viability assay, release of ATP measured with bioluminescent assay, release of DNA measured by fluorometry and qPCR, as well as bacterial culture. Results comparable to standard lysis techniques were achievable at temperatures greater than 65 °C and heating durations between 1 and 60 s.

  5. One-step cell lysis suitable for quantitative bacteria detection in inhibitor-laden sands

    Lim, Hyun Jeong; Choi, Jung-Hyun; Son, Ahjeong

    2015-04-01

    Complexity and heterogeneity of soils often hinder effective DNA extraction from the soil matrix. In particular, conventional DNA extraction techniques require extensive purification which makes DNA extraction time-consuming and labor-intensive. Other drawbacks include lower recovery yield, degradation, and damage of DNA, which are also caused by intensive purifications during DNA extraction. Therefore a rapid and simple and yet effective DNA pretreatment method is preferred for environmental monitoring and screening. This study has evaluated the feasibility of simple physical pretreatment for effective cell lysis of bacteria in sands. Bead beating method was selected as an effective physical cell lysis method in this study. We examined the capability of this physical lysis for Pseudomonas putida seeded sands without additional chemical purification steps. The lysate from the method was analysed by the quantitative polymerase chain reaction (qPCR) assay and subsequently compared to that by commercial DNA extraction kit. The best lysis condition (treatment with 0.1 mm glass beads at 3000 rpm for 3 minutes) was selected. The qPCR results of bead beating treated samples showed the better performance than that of conventional DNA extraction kit. Moreover, the qPCR assay was performed to the sands laden with qPCR inhibitors (humic acids, clay, and magnesium), which generally present in environmental samples. Further experiments with the sands containing less than 10 μg/g of humic acids and 70% of clay showed successful quantification results of qPCR assay. In conclusion, the bead beating method is useful for simplified DNA extraction prior to qPCR analysis for sand samples of particular composition. It is expected that this approach will be beneficial for environmental in-situ analysis or immediate pre-screening. It also provides the groundwork for future studies with real soil samples that have various physico-chemical properties.

  6. Immobilized lysozyme for the continuous lysis of lactic bacteria in wine: Bench-scale fluidized-bed reactor study.

    Cappannella, Elena; Benucci, Ilaria; Lombardelli, Claudio; Liburdi, Katia; Bavaro, Teodora; Esti, Marco

    2016-11-01

    Lysozyme from hen egg white (HEWL) was covalently immobilized on spherical supports based on microbial chitosan in order to develop a system for the continuous, efficient and food-grade enzymatic lysis of lactic bacteria (Oenococcus oeni) in white and red wine. The objective is to limit the sulfur dioxide dosage required to control malolactic fermentation, via a cell concentration typical during this process. The immobilization procedure was optimized in batch mode, evaluating the enzyme loading, the specific activity, and the kinetic parameters in model wine. Subsequently, a bench-scale fluidized-bed reactor was developed, applying the optimized process conditions. HEWL appeared more effective in the immobilized form than in the free one, when the reactor was applied in real white and red wine. This preliminary study suggests that covalent immobilization renders the enzyme less sensitive to the inhibitory effect of wine flavans. PMID:27211619

  7. Comparison of point-of-care-compatible lysis methods for bacteria and viruses.

    Heiniger, Erin K; Buser, Joshua R; Mireles, Lillian; Zhang, Xiaohong; Ladd, Paula D; Lutz, Barry R; Yager, Paul

    2016-09-01

    Nucleic acid sample preparation has been an especially challenging barrier to point-of-care nucleic acid amplification tests in low-resource settings. Here we provide a head-to-head comparison of methods for lysis of, and nucleic acid release from, several pathogenic bacteria and viruses-methods that are adaptable to point-of-care usage in low-resource settings. Digestion with achromopeptidase, a mixture of proteases and peptidoglycan-specific hydrolases, followed by thermal deactivation in a boiling water bath, effectively released amplifiable nucleic acid from Staphylococcus aureus, Bordetella pertussis, respiratory syncytial virus, and influenza virus. Achromopeptidase was functional after dehydration and reconstitution, even after eleven months of dry storage without refrigeration. Mechanical lysis methods proved to be effective against a hard-to-lyse Mycobacterium species, and a miniature bead-mill, the AudioLyse, is shown to be capable of releasing amplifiable DNA and RNA from this species. We conclude that point-of-care-compatible sample preparation methods for nucleic acid tests need not introduce amplification inhibitors, and can provide amplification-ready lysates from a wide range of bacterial and viral pathogens. PMID:27424294

  8. A super-family of transcriptional activators regulates bacteriophage packaging and lysis in Gram-positive bacteria.

    Quiles-Puchalt, Nuria; Tormo-Más, María Ángeles; Campoy, Susana; Toledo-Arana, Alejandro; Monedero, Vicente; Lasa, Iñigo; Novick, Richard P; Christie, Gail E; Penadés, José R

    2013-08-01

    The propagation of bacteriophages and other mobile genetic elements requires exploitation of the phage mechanisms involved in virion assembly and DNA packaging. Here, we identified and characterized four different families of phage-encoded proteins that function as activators required for transcription of the late operons (morphogenetic and lysis genes) in a large group of phages infecting Gram-positive bacteria. These regulators constitute a super-family of proteins, here named late transcriptional regulators (Ltr), which share common structural, biochemical and functional characteristics and are unique to this group of phages. They are all small basic proteins, encoded by genes present at the end of the early gene cluster in their respective phage genomes and expressed under cI repressor control. To control expression of the late operon, the Ltr proteins bind to a DNA repeat region situated upstream of the terS gene, activating its transcription. This involves the C-terminal part of the Ltr proteins, which control specificity for the DNA repeat region. Finally, we show that the Ltr proteins are the only phage-encoded proteins required for the activation of the packaging and lysis modules. In summary, we provide evidence that phage packaging and lysis is a conserved mechanism in Siphoviridae infecting a wide variety of Gram-positive bacteria. PMID:23771138

  9. Magnetization processes in magnetotactic bacteria systems

    Polyakova, T.; Zablotskyy, Vitaliy A.

    2005-01-01

    Roč. 293, - (2005), s. 365-370. ISSN 0304-8853. [International Conference on Scientific and Clinical Aplications of Magnetic Carriers. Lyon, 20.05.04-22.05.04] Grant ostatní: MCF: Nanomag-Lab(XE) N 2004-003177 Institutional research plan: CEZ:AV0Z10100520 Keywords : magnetotactic bacteria * magnetization process * chemotaxis * bacteria * magnetosomes * chain formation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.985, year: 2005

  10. Maintenance, endogeneous, respiration, lysis, decay and predation

    loosdrecht, Marc C. M. Van; Henze, Mogens

    1999-01-01

    In activated sludge processes an increased sludge age is associated with a decreased sludge production. This phenomenon is generally interpreted as a result of endogenous respiration processes. In the activated sludge models cell lysis (or decay) is incorporated. The lysis is modelled such that it...... mechanism is microbiologically correct. The lysis/decay model mechanism is a strongly simplified representation of reality. This paper tries to review the processes grouped under endogenous respiration in activated sludge models. Mechanisms and processes such as maintenance, lysis, internal and external...... maintenance processes. This conversion will in general be denoted as endogenous respiration. Based on the literature review the phenomena are discussed and organised, in order to create a working platform for discussing more detailed activated sludge models, one of which is being sketched. (C) 1999 IAWQ...

  11. Glaucoma laser suture lysis.

    Macken, P; Buys, Y; Trope, G E

    1996-01-01

    AIM: Suture lysis is commonly performed after trabeculectomy to improve bleb function. It is often thought to be an innocuous procedure. This is the first large study to determine the safety of the procedure and compare results with a control group. METHODS: Two hundred successive trabeculectomies performed between January 1992 and October 1993 were analysed. RESULTS: Ninety nine eyes underwent trabeculectomy and suture lysis; 101 eyes underwent trabeculectomy and did not require postoperativ...

  12. Factors influencing lysis time stochasticity in bacteriophage λ

    Dennehy John J

    2011-08-01

    Full Text Available Abstract Background Despite identical genotypes and seemingly uniform environments, stochastic gene expression and other dynamic intracellular processes can produce considerable phenotypic diversity within clonal microbes. One trait that provides a good model to explore the molecular basis of stochastic variation is the timing of host lysis by bacteriophage (phage. Results Individual lysis events of thermally-inducible λ lysogens were observed using a temperature-controlled perfusion chamber mounted on an inverted microscope. Both mean lysis time (MLT and its associated standard deviation (SD were estimated. Using the SD as a measure of lysis time stochasticity, we showed that lysogenic cells in controlled environments varied widely in lysis times, and that the level of lysis time stochasticity depended on allelic variation in the holin sequence, late promoter (pR' activity, and host growth rate. In general, the MLT was positively correlated with the SD. Both lower pR' activities and lower host growth rates resulted in larger SDs. Results from premature lysis, induced by adding KCN at different time points after lysogen induction, showed a negative correlation between the timing of KCN addition and lysis time stochasticity. Conclusions Taken together with results published by others, we conclude that a large fraction of λ lysis time stochasticity is the result of random events following the expression and diffusion of the holin protein. Consequently, factors influencing the timing of reaching critical holin concentrations in the cell membrane, such as holin production rate, strongly influence the mean lysis time and the lysis time stochasticity.

  13. Maintenance, endogeneous, respiration, lysis, decay and predation

    loosdrecht, Marc C. M. Van; Henze, Mogens

    1999-01-01

    mechanism is microbiologically correct. The lysis/decay model mechanism is a strongly simplified representation of reality. This paper tries to review the processes grouped under endogenous respiration in activated sludge models. Mechanisms and processes such as maintenance, lysis, internal and external...... maintenance processes. This conversion will in general be denoted as endogenous respiration. Based on the literature review the phenomena are discussed and organised, in order to create a working platform for discussing more detailed activated sludge models, one of which is being sketched. (C) 1999 IAWQ...

  14. Revision stapes surgery for lysis of the long process of the incus: comparing hydroxyapatite bone cement versus malleovestibulopexy and total ossicular replacement prosthesis.

    Pitiot, Vincent; Hermann, Ruben; Tringali, Stéphane; Dubreuil, Christian; Truy, Eric

    2016-09-01

    The objective of the study was to report audiological results in revision stapes surgery, comparing hydroxyapatite (HAP) bone cement, malleovestibular (MV) prosthesis, and total ossicular replacement prosthesis (TORP). The study is a retrospective case review conducted in a tertiary referral center. Patients treated for revision stapes surgery from 2010 to 2014, where a lysis of the long process of the incus (LPI) was observed with the use of HAP bone cement, MV prosthesis, or a TORP were included in the study. The main outcomes measured were pre- and postoperative bone conduction (BC) and air conduction (AC) pure-tone averages (PTA) (0.5, 1, 2, 3 kHz), including high frequencies BC (HFBC) (1, 2, 3, 4 kHz) and air-bone gap (ABG). 107 revision stapes surgery were performed in 96 ears. Main cause of failure was LPI lysis in 38 cases (39.6 %). 31 patients were analyzed: HAP bone cement was used in 11 patients (Group I), MV prosthesis in ten patients (Group II), and TORP in ten patients (Group III). The mean post-operative ABG was 10.7 dB (±7.4) (p = 0.003), 10.7 dB (±8.8) (p = 0.001), and 16.9 dB (±9.8) (p = 0.001), respectively. There were no significant differences between groups. In Group I, the mean change in HFBC revealed an improvement of 5.6 dB (±7.9) (p = 0.03), while in Group III there was a significant deterioration of the thresholds of 5.8 dB (±7.6) (p = 0.04). There were no cases of post-operative anacusis. In revision stapes surgery when LPI is eroded, we recommend to perform a cement ossiculoplasty for stabilizing a standard Teflon piston when LPI is still usable, the LPI lengthening with cement being not recommended. When LPI is too eroded, we prefer performing a malleovestibulopexy, and reserve TORP for cases with a bad anatomical presentation. PMID:26690574

  15. Decontamination of airborne bacteria in meat processing plants

    Air has been established as a source of bacterial contamination in meat processing facilities. Airborne bacteria may affect product shelf life, and have food safety implications. The effectiveness of reactive oxygen species (ROS) generating AirOcare equipment on the reduction of airborne bacteria in...

  16. Penicillin-induced lysis of Streptococcus mutans.

    Kral, T A; Callaway, M D

    1984-01-01

    Treatment of Streptococcus mutans GS-5 cells with concentrations of penicillin G within a relatively narrow range resulted in substantial lysis. This penicillin-induced lysis was dependent upon cell density and pH of the lysis medium. Other oral streptococci (Streptococcus sobrinus, Streptococcus rattus, and Streptococcus cricetus) also demonstrated substantial levels of penicillin-induced lysis under appropriate conditions. Lesser degrees of lysis were seen in a related organism, Streptococc...

  17. Decontamination of airborne bacteria in meat processing plants

    The effectiveness of reactive oxygen species (ROS) generating AirOcare equipment on the reduction of airborne bacteria in a meat processing environment was determined. Bacterial strains found in ground beef were used to artificially contaminate the air using a 6-jet Collison nebulizer. Airborne bact...

  18. Diversity of lactic acid bacteria of the bioethanol process

    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.

  19. Membrane fusion during phage lysis.

    Rajaure, Manoj; Berry, Joel; Kongari, Rohit; Cahill, Jesse; Young, Ry

    2015-04-28

    In general, phages cause lysis of the bacterial host to effect release of the progeny virions. Until recently, it was thought that degradation of the peptidoglycan (PG) was necessary and sufficient for osmotic bursting of the cell. Recently, we have shown that in Gram-negative hosts, phage lysis also requires the disruption of the outer membrane (OM). This is accomplished by spanins, which are phage-encoded proteins that connect the cytoplasmic membrane (inner membrane, IM) and the OM. The mechanism by which the spanins destroy the OM is unknown. Here we show that the spanins of the paradigm coliphage lambda mediate efficient membrane fusion. This supports the notion that the last step of lysis is the fusion of the IM and OM. Moreover, data are provided indicating that spanin-mediated fusion is regulated by the meshwork of the PG, thus coupling fusion to murein degradation by the phage endolysin. Because endolysin function requires the formation of μm-scale holes by the phage holin, the lysis pathway is seen to require dramatic dynamics on the part of the OM and IM, as well as destruction of the PG. PMID:25870259

  20. Microfluidic systems for cell lysis

    Svobodová, Ivona; Grym, Jakub; Klepárník, Karel; Foret, František

    2006. [Annual European Conference on Micro&Nanoscale Technologies for the Biosciences /10./. 14.11.2006-16.11.2006, Montreux] R&D Projects: GA AV ČR IAA400310506; GA AV ČR KAN400310651; GA MŠk LC06023; GA ČR GA203/06/1685 Institutional research plan: CEZ:AV0Z40310501 Keywords : cell lysis * yeast cells * microfluidic device Subject RIV: CB - Analytical Chemistry, Separation

  1. Sample preparation module for bacterial lysis and isolation of DNA from human urine

    Kulinski, M. Dominika; Mahalanabis, Madhumita; Gillers, Sara; Zhang, Jane Y.; Singh, Satish; Klapperich, Catherine M.

    2009-01-01

    Silica impregnated polymer monolithic columns may provide a simple method for lysing and extracting DNA from bacteria inside of microfluidic chips. Here we use Escherichia coli as a test organism for a point of care thermoplastic microfluidic module designed to take in a urine sample, mix it with lysis buffer, and perform a hybrid chemical/mechanical lysis and solid phase extraction of nucleic acids from the sample. To demonstrate proof-of-concept, we doped human hematuric urine samples with ...

  2. Role of Heterotrophic Bacteria in Marine Ecological Processes

    Ramaiah, N.

    that ubiquitous and self-regulating microbial communities provided the foundation to our understanding on the processes in marine food-web (Landry, 2001). Heterotrophy in the Marine Environment Marine heterotrophy involving all animals and many microbes is a... factors ranging from 10 to 40fg C cell-1 (Pomeroy and Joint, 1999) to figure out the carbon pool in marine bacteria. However, the consensus arrived by many recent investigations suggest an average of 11 fg C cell-1 (Landry et al 2001). In comparison...

  3. Requirements for the triggering of lysis by cloned murine cytolytic T lymphocytes (CTL)

    Lancki, D.W.; Weiss, A.; Fitch, F.W.

    1986-03-05

    Cloned murine cytolytic T lymphocytes (CTL) having defined specificity were triggered by the phorbol ester PMA + a calcium ionophore (either A23187 or Ionomycin) to lyse syngeneic or third party target cells efficiently. Neither PMA nor calcium ionophore alone induced efficient lysis. The characteristics of the lytic process induced by these signals are similar to those of antigen specific or lectin facilitated lysis by CTL: lysis is calcium and temperature dependent, and shows directionality and kinetics similar to lysis mediated via the antigen receptor. Helper T lymphocytes were not induced by these agents to lyse target cells efficiently. Activation of L3 CTL clone lysis by PMA + ionophore differed from antigen-mediated activation in specificity and in susceptibility to inhibition by cytochalasin B, an inhibitor of antigen mediated conjugate formation. Anti-LFA-1 monoclonal antibodies inhibited antigen-mediated, lectin-facilitated, or PMA + ionophore induced lysis. Anti-Lyt-2 and anti-receptor antibodies had little if any effect on lysis induced by PMA + ionophore. The triggering of lysis with PMA + ionophore appears to involve intracellular signals similar to those involved in lysis mediated by the antigen receptor.

  4. Explosive cell lysis as a mechanism for the biogenesis of bacterial membrane vesicles and biofilms.

    Turnbull, Lynne; Toyofuku, Masanori; Hynen, Amelia L; Kurosawa, Masaharu; Pessi, Gabriella; Petty, Nicola K; Osvath, Sarah R; Cárcamo-Oyarce, Gerardo; Gloag, Erin S; Shimoni, Raz; Omasits, Ulrich; Ito, Satoshi; Yap, Xinhui; Monahan, Leigh G; Cavaliere, Rosalia; Ahrens, Christian H; Charles, Ian G; Nomura, Nobuhiko; Eberl, Leo; Whitchurch, Cynthia B

    2016-01-01

    Many bacteria produce extracellular and surface-associated components such as membrane vesicles (MVs), extracellular DNA and moonlighting cytosolic proteins for which the biogenesis and export pathways are not fully understood. Here we show that the explosive cell lysis of a sub-population of cells accounts for the liberation of cytosolic content in Pseudomonas aeruginosa biofilms. Super-resolution microscopy reveals that explosive cell lysis also produces shattered membrane fragments that rapidly form MVs. A prophage endolysin encoded within the R- and F-pyocin gene cluster is essential for explosive cell lysis. Endolysin-deficient mutants are defective in MV production and biofilm development, consistent with a crucial role in the biogenesis of MVs and liberation of extracellular DNA and other biofilm matrix components. Our findings reveal that explosive cell lysis, mediated through the activity of a cryptic prophage endolysin, acts as a mechanism for the production of bacterial MVs. PMID:27075392

  5. Trypanosome Lytic Factor-1 Initiates Oxidation-stimulated Osmotic Lysis of Trypanosoma brucei brucei.

    Greene, Amy Styer; Hajduk, Stephen L

    2016-02-01

    Human innate immunity against the veterinary pathogen Trypanosoma brucei brucei is conferred by trypanosome lytic factors (TLFs), against which human-infective T. brucei gambiense and T. brucei rhodesiense have evolved resistance. TLF-1 is a subclass of high density lipoprotein particles defined by two primate-specific apolipoproteins: the ion channel-forming toxin ApoL1 (apolipoprotein L1) and the hemoglobin (Hb) scavenger Hpr (haptoglobin-related protein). The role of oxidative stress in the TLF-1 lytic mechanism has been controversial. Here we show that oxidative processes are involved in TLF-1 killing of T. brucei brucei. The lipophilic antioxidant N,N'-diphenyl-p-phenylenediamine protected TLF-1-treated T. brucei brucei from lysis. Conversely, lysis of TLF-1-treated T. brucei brucei was increased by the addition of peroxides or thiol-conjugating agents. Previously, the Hpr-Hb complex was postulated to be a source of free radicals during TLF-1 lysis. However, we found that the iron-containing heme of the Hpr-Hb complex was not involved in TLF-1 lysis. Furthermore, neither high concentrations of transferrin nor knock-out of cytosolic lipid peroxidases prevented TLF-1 lysis. Instead, purified ApoL1 was sufficient to induce lysis, and ApoL1 lysis was inhibited by the antioxidant DPPD. Swelling of TLF-1-treated T. brucei brucei was reminiscent of swelling under hypotonic stress. Moreover, TLF-1-treated T. brucei brucei became rapidly susceptible to hypotonic lysis. T. brucei brucei cells exposed to peroxides or thiol-binding agents were also sensitized to hypotonic lysis in the absence of TLF-1. We postulate that ApoL1 initiates osmotic stress at the plasma membrane, which sensitizes T. brucei brucei to oxidation-stimulated osmotic lysis. PMID:26645690

  6. An attempt to improve the results of treatment for breast cancer complicated by lysis

    G. A. Khakimov

    2014-01-01

    Full Text Available Lysis in locally advanced breast cancer (BC is not a sign of tumor process dissemination. The correct elaboration of management tactics for such patients may achieve rather good early and late results. The doxorubicin + xeloda regimen for BC complicated by lysis has some advantage over the FAC regimen, without additionally increasing the rate of adverse reactions and worsening the quality of life.

  7. An attempt to improve the results of treatment for breast cancer complicated by lysis

    G. A. Khakimov; A. K. Madalimov; Sh. G. Khakimova; Kh. I. Dzhumaniyozov

    2014-01-01

    Lysis in locally advanced breast cancer (BC) is not a sign of tumor process dissemination. The correct elaboration of management tactics for such patients may achieve rather good early and late results. The doxorubicin + xeloda regimen for BC complicated by lysis has some advantage over the FAC regimen, without additionally increasing the rate of adverse reactions and worsening the quality of life.

  8. Genetic Dissection of T4 Lysis

    Moussa, Samir H.; Lawler, Jessica L.

    2014-01-01

    t is the holin gene for coliphage T4, encoding a 218-amino-acid (aa) protein essential for the inner membrane hole formation that initiates lysis and terminates the phage infection cycle. T is predicted to be an integral membrane protein that adopts an Nin-Cout topology with a single transmembrane domain (TMD). This holin topology is different from those of the well-studied holins S105 (3 TMDs; Nout-Cin) of the coliphage lambda and S68 (2 TMDs; Nin-Cin) of the lambdoid phage 21. Here, we used random mutagenesis to construct a library of lysis-defective alleles of t to discern residues and domains important for holin function and for the inhibition of lysis by the T4 antiholin, RI. The results show that mutations in all 3 topological domains (N-terminal cytoplasmic, TMD, and C-terminal periplasmic) can abrogate holin function. Additionally, several lysis-defective alleles in the C-terminal domain are no longer competent in binding RI. Taken together, these results shed light on the roles of the previously uncharacterized N-terminal and C-terminal domains in lysis and its real-time regulation. PMID:24706740

  9. Development of an Integrated Chip for Automatic Tracking and Positioning Manipulation for Single Cell Lysis

    Chao-Wang Young

    2012-02-01

    Full Text Available This study adopted a microelectromechanical fabrication process to design a chip integrated with electroosmotic flow and dielectrophoresis force for single cell lysis. Human histiocytic lymphoma U937 cells were driven rapidly by electroosmotic flow and precisely moved to a specific area for cell lysis. By varying the frequency of AC power, 15 V AC at 1 MHz of frequency configuration achieved 100% cell lysing at the specific area. The integrated chip could successfully manipulate single cells to a specific position and lysis. The overall successful rate of cell tracking, positioning, and cell lysis is 80%. The average speed of cell driving was 17.74 μm/s. This technique will be developed for DNA extraction in biomolecular detection. It can simplify pre-treatment procedures for biotechnological analysis of samples.

  10. Microfluidic device for acoustic cell lysis

    Branch, Darren W.; Cooley, Erika Jane; Smith, Gennifer Tanabe; James, Conrad D.; McClain, Jaime L.

    2015-08-04

    A microfluidic acoustic-based cell lysing device that can be integrated with on-chip nucleic acid extraction. Using a bulk acoustic wave (BAW) transducer array, acoustic waves can be coupled into microfluidic cartridges resulting in the lysis of cells contained therein by localized acoustic pressure. Cellular materials can then be extracted from the lysed cells. For example, nucleic acids can be extracted from the lysate using silica-based sol-gel filled microchannels, nucleic acid binding magnetic beads, or Nafion-coated electrodes. Integration of cell lysis and nucleic acid extraction on-chip enables a small, portable system that allows for rapid analysis in the field.

  11. Fed-Batch Production of Bacterial Ghosts Using Dielectric Spectroscopy for Dynamic Process Control

    Andrea Meitz

    2016-03-01

    Full Text Available The Bacterial Ghost (BG platform technology evolved from a microbiological expression system incorporating the ϕX174 lysis gene E. E-lysis generates empty but structurally intact cell envelopes (BGs from Gram-negative bacteria which have been suggested as candidate vaccines, immunotherapeutic agents or drug delivery vehicles. E-lysis is a highly dynamic and complex biological process that puts exceptional demands towards process understanding and control. The development of a both economic and robust fed-batch production process for BGs required a toolset capable of dealing with rapidly changing concentrations of viable biomass during the E-lysis phase. This challenge was addressed using a transfer function combining dielectric spectroscopy and soft-sensor based biomass estimation for monitoring the rapid decline of viable biomass during the E-lysis phase. The transfer function was implemented to a feed-controller, which followed the permittivity signal closely and was capable of maintaining a constant specific substrate uptake rate during lysis phase. With the described toolset, we were able to increase the yield of BG production processes by a factor of 8–10 when compared to currently used batch procedures reaching lysis efficiencies >98%. This provides elevated potentials for commercial application of the Bacterial Ghost platform technology.

  12. Electrical lysis of cells for detergent-free droplet assays

    N. de Lange; Tran, T. M.; Abate, A. R.

    2016-01-01

    Efficient lysis is critical when analyzing single cells in microfluidic droplets, but existing methods utilize detergents that can interfere with the assays to be performed. We demonstrate robust cell lysis without the use of detergents or other chemicals. In our method, cells are exposed to electric field immediately before encapsulation in droplets, resulting in cell lysis. We characterize lysis efficiency as a function of control parameters and demonstrate compatibility with enzymatic assa...

  13. Use of Surface Enhanced Blocking (SEB) Electrodes for Microbial Cell Lysis in Flow-Through Devices

    Talebpour, Abdossamad; Maaskant, Robert; Khine, Aye Aye; Alavie, Tino

    2014-01-01

    By simultaneously subjecting microbial cells to high amplitude pulsed electric fields and flash heating of the cell suspension fluid, effective release of intracellular contents was achieved. The synergistic effect of the applied electric field and elevated temperature on cell lysis in a flow-through device was demonstrated for Gram-negative and Gram-positive bacteria, and Mycobacterium species. The resulting lysate is suitable for downstream nucleic acid amplification and detection without r...

  14. Viral lysis of Phaeocystis pouchetii: implications for algal population dynamics and heterotrophic C, N and P cycling

    Haaber, Jakob Brandt Borup; Middelboe, Mathias

    2009-01-01

    A model ecosystem with two autotrophic flagellates, Phaeocystis pouchetii and Rhodomonas salina, a virus specific to P. pouchetii (PpV) and bacteria and heterotrophic nanoflagellates was used to investigate effects of viral lysis on algal population dynamics and heterotrophic nitrogen and...

  15. Micro Corona Ionizer as an Ozone Source for Bacterial Cell Lysis

    Lee, Eun-Hee; Lim, Hyun Jeong; Chua, Beelee; Son, Ahjeong

    2015-04-01

    DNA extraction is a critical process of DNA assays including polymerase chain reaction (PCR), microarrays, molecular cloning, and DNA hybridization which has been well established and can be implemented by commercial kits. DNA extraction involves cell lysis, precipitation, and purification through the combination of physical and chemical processes. Cell lysis is essential to high DNA recovery yield which can be achieved via a variety of physical, chemical, and enzymatic methods. However, these methods were originally developed for bioassays that were labor intensive, time consuming, and vulnerable to contamination and inhibition. Here, we proposed to employ a micro corona ionizer as an ozone source to lyse bacterial cells. Ozone has been well known and used as a disinfectant which allows cell lysis and DNA extraction. Previously, we have shown that a micro corona ionizer is capable of generating a significant amount of ozone. In this study, we employed the micro corona ionizer for the bacterial cell lysis which consists of a 50 μm diameter cantilever wire as the discharge cathode and a 50 μm thick copper foil as anode. Applied voltages varied from 1900 to 2200 V with corresponding corona currents from 16 to 28 μA. The resultant ozone (concentration > 0.14 ppm) generated from the micro corona ionizer was bubbled into the sample via a miniature pump. We demonstrated the cell lysis of Pseudomonas putida as the target bacterium using the micro corona ionizer. At a flow rate of 38 ml/min and applied corona voltage of 2000 V, 98.5 ± 0.2% lysis (normalized to sonication result) was achieved after 10 min. In comparison, untreated and air-treated samples showed normalized % lysis of 11.9 ± 2.4 and 36.1 ± 1.7%, respectively. We also showed that the cell lysis efficiency could be significantly increased by increasing the flow rate and the applied corona voltage. By comparing the experimental results for continuous and pulsed treatment, we verified that the percentage of

  16. Sub classification and targeted characterization of prophage-encoded two-component cell lysis cassette

    K V Srividhya; S Krishnaswamy

    2007-08-01

    Bacteriophage induced lysis of host bacterial cell is mediated by a two component cell lysis cassette comprised of holin and lysozyme. Prophages are integrated forms of bacteriophages in bacterial genomes providing a repertoire for bacterial evolution. Analysis using the prophage database (http://bicmku.in:8082) constructed by us showed 47 prophages were associated with putative two component cell lysis genes. These proteins cluster into four different subgroups. In this process, a putative holin (essd) and endolysin (ybcS), encoded by the defective lambdoid prophage DLP12 was found to be similar to two component cell lysis genes in functional bacteriophages like p21 and P1. The holin essd was found to have a characteristic dual start motif with two transmembrane regions and C-terminal charged residues as in class II holins. Expression of a fusion construct of essd in Escherichia coli showed slow growth. However, under appropriate conditions, this protein could be over expressed and purified for structure function studies. The second component of the cell lysis cassette, ybcS, was found to have an N-terminal SAR (Signal Arrest Release) transmembrane domain. The construct of ybcS has been over expressed in E. coli and the purified protein was functional, exhibiting lytic activity against E. coli and Salmonella typhi cell wall substrate. Such targeted sequence-structure-function characterization of proteins encoded by cryptic prophages will help understand the contribution of prophage proteins to bacterial evolution.

  17. Bioleaching of spent hydro-processing catalyst using acidophilic bacteria and its kinetics aspect

    Mishra, Debaraj [Mineral and Material Processing Division, Korea Institute of Geosciences and Mineral Resources, Daejeon 305-350 (Korea, Republic of); Department of Microbiology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Kim, Dong J. [Mineral and Material Processing Division, Korea Institute of Geosciences and Mineral Resources, Daejeon 305-350 (Korea, Republic of)], E-mail: djkim@kigam.re.kr; Ralph, David E. [AJ Parker CRC for Hydrometallurgy, Murdoch University, South Street Murdoch, Perth 6153 (Australia); Ahn, Jong G. [Mineral and Material Processing Division, Korea Institute of Geosciences and Mineral Resources, Daejeon 305-350 (Korea, Republic of); Rhee, Young H. [Department of Microbiology, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

    2008-04-15

    Bioleaching of metals from hazardous spent hydro-processing catalysts was attempted in the second stage after growing the bacteria with sulfur in the first stage. The first stage involved transformation of elemental sulfur particles to sulfuric acid through an oxidation process by acidophilic bacteria. In the second stage, the acidic medium was utilized for the leaching process. Nickel, vanadium and molybdenum contained within spent catalyst were leached from the solid materials to liquid medium by the action of sulfuric acid that was produced by acidophilic leaching bacteria. Experiments were conducted varying the reaction time, amount of spent catalysts, amount of elemental sulfur and temperature. At 50 g/L spent catalyst concentration and 20 g/L elemental sulfur, 88.3% Ni, 46.3% Mo, and 94.8% V were recovered after 7 days. Chemical leaching with commercial sulfuric acid of the similar amount that produced by bacteria was compared. Thermodynamic parameters were calculated and the nature of reaction was found to be exothermic. Leaching kinetics of the metals was represented by different reaction kinetic equations, however, only diffusion controlled model showed the best correlation here. During the whole process Mo showed low dissolution because of substantiate precipitation with leach residues as MoO{sub 3}. Bioleach residues were characterized by EDX and XRD.

  18. Bioleaching of spent hydro-processing catalyst using acidophilic bacteria and its kinetics aspect

    Bioleaching of metals from hazardous spent hydro-processing catalysts was attempted in the second stage after growing the bacteria with sulfur in the first stage. The first stage involved transformation of elemental sulfur particles to sulfuric acid through an oxidation process by acidophilic bacteria. In the second stage, the acidic medium was utilized for the leaching process. Nickel, vanadium and molybdenum contained within spent catalyst were leached from the solid materials to liquid medium by the action of sulfuric acid that was produced by acidophilic leaching bacteria. Experiments were conducted varying the reaction time, amount of spent catalysts, amount of elemental sulfur and temperature. At 50 g/L spent catalyst concentration and 20 g/L elemental sulfur, 88.3% Ni, 46.3% Mo, and 94.8% V were recovered after 7 days. Chemical leaching with commercial sulfuric acid of the similar amount that produced by bacteria was compared. Thermodynamic parameters were calculated and the nature of reaction was found to be exothermic. Leaching kinetics of the metals was represented by different reaction kinetic equations, however, only diffusion controlled model showed the best correlation here. During the whole process Mo showed low dissolution because of substantiate precipitation with leach residues as MoO3. Bioleach residues were characterized by EDX and XRD

  19. Bioleaching of spent hydro-processing catalyst using acidophilic bacteria and its kinetics aspect.

    Mishra, Debaraj; Kim, Dong J; Ralph, David E; Ahn, Jong G; Rhee, Young H

    2008-04-15

    Bioleaching of metals from hazardous spent hydro-processing catalysts was attempted in the second stage after growing the bacteria with sulfur in the first stage. The first stage involved transformation of elemental sulfur particles to sulfuric acid through an oxidation process by acidophilic bacteria. In the second stage, the acidic medium was utilized for the leaching process. Nickel, vanadium and molybdenum contained within spent catalyst were leached from the solid materials to liquid medium by the action of sulfuric acid that was produced by acidophilic leaching bacteria. Experiments were conducted varying the reaction time, amount of spent catalysts, amount of elemental sulfur and temperature. At 50 g/L spent catalyst concentration and 20 g/L elemental sulfur, 88.3% Ni, 46.3% Mo, and 94.8% V were recovered after 7 days. Chemical leaching with commercial sulfuric acid of the similar amount that produced by bacteria was compared. Thermodynamic parameters were calculated and the nature of reaction was found to be exothermic. Leaching kinetics of the metals was represented by different reaction kinetic equations, however, only diffusion controlled model showed the best correlation here. During the whole process Mo showed low dissolution because of substantiate precipitation with leach residues as MoO3. Bioleach residues were characterized by EDX and XRD. PMID:17825485

  20. Simulation of bacteria transport processes in a river with Flow3D

    Schwarzwälder, Kordula; Bui, Minh Duc; Rutschmann, Peter

    2014-05-01

    Water quality aspects are getting more and more important due to the European water Framework directive (WFD). One problem related to this topic is the inflow of untreated wastewater due to combined sewer overflows into a river. The wastewater mixture contains even bacteria like E. coli and Enterococci which are markers for water quality. In our work we investigated the transport of these bacteria in river Isar by using a large-scale flume in the outside area of our lab (Oskar von Miller Institute). Therefor we could collect basic data and knowledge about the processes which occur during bacteria sedimentation and remobilisation. In our flume we could use the real grain with the exact size distribution curve as in the river Isar which we want to simulate and we had the chance to nurture a biofilm which is realistic for the analysed situation. This biofilm plays an important role in the remobilisation processes, because the bacteria are hindered to be washed out back into the bulk phase as fast and in such an amount as this would happen without biofilm. The results of our experiments are now used for a module in the 3D software Flow3D to simulate the effects of a point source inlet of raw wastewater on the water quality. Therefor we have to implement the bacteria not as a problem of concentration with advection and diffusion but as single particles which can be inactivated during the process of settling and need to be hindered from remobilisation by the biofilm. This biofilm has special characteristic, it is slippery and has a special thickness which influences the chance of bacteria being removed. To achieve realistic results we have to include the biofilm with more than a probabilistic-tool to make sure that our module is transferable. The module should be as flexible as possible to be improved step by step with increasing quality of dataset.

  1. The euglobulin clot lysis time to assess the impact of nanoparticles on fibrinolysis

    Minet, Valentine, E-mail: valentine.minet@unamur.be; Alpan, Lutfiye; Mullier, François [University of Namur – UNamur, Department of Pharmacy, Namur Thrombosis and Hemostasis Center (NTHC), Namur Nanosafety Center (NNC), NAmur Research Institute for Life Sciences NARILIS (Belgium); Toussaint, Olivier [Laboratory of Cellular Biochemistry and Biology (URBC) (Belgium); Lucas, Stéphane [University of Namur (UNamur), Research Centre for the Physics of Matter and Radiation (PMR-LARN), Namur Nanosafety Center NNC, NAmur Research Institute for Life Sciences NARILIS (Belgium); Dogné, Jean-Michel; Laloy, Julie, E-mail: julie.laloy@unamur.be [University of Namur – UNamur, Department of Pharmacy, Namur Thrombosis and Hemostasis Center (NTHC), Namur Nanosafety Center (NNC), NAmur Research Institute for Life Sciences NARILIS (Belgium)

    2015-07-15

    Nanoparticles (NPs) are developed for many applications in various fields, including nanomedicine. The NPs used in nanomedicine may disturb homeostasis in blood. Secondary hemostasis (blood coagulation) and fibrinolysis are complex physiological processes regulated by activators and inhibitors. An imbalance of this system can either lead to the development of hemorrhages or thrombosis. No data are currently available on the impact of NPs on fibrinolysis. The objectives of this study are (1) to select a screening test to study ex vivo the impact of NPs on fibrinolysis and (2) to test NPs with different physicochemical properties. Euglobulin clot lysis time test was selected to screen the impact of some NPs on fibrinolysis using normal pooled plasma. A dose-dependent decrease in the lysis time was observed with silicon dioxide and silver NPs without disturbing the fibrin network. Carbon black, silicon carbide, and copper oxide did not affect the lysis time at the tested concentrations.

  2. The euglobulin clot lysis time to assess the impact of nanoparticles on fibrinolysis

    Nanoparticles (NPs) are developed for many applications in various fields, including nanomedicine. The NPs used in nanomedicine may disturb homeostasis in blood. Secondary hemostasis (blood coagulation) and fibrinolysis are complex physiological processes regulated by activators and inhibitors. An imbalance of this system can either lead to the development of hemorrhages or thrombosis. No data are currently available on the impact of NPs on fibrinolysis. The objectives of this study are (1) to select a screening test to study ex vivo the impact of NPs on fibrinolysis and (2) to test NPs with different physicochemical properties. Euglobulin clot lysis time test was selected to screen the impact of some NPs on fibrinolysis using normal pooled plasma. A dose-dependent decrease in the lysis time was observed with silicon dioxide and silver NPs without disturbing the fibrin network. Carbon black, silicon carbide, and copper oxide did not affect the lysis time at the tested concentrations

  3. On-chip cell lysis by antibacterial non-leaching reusable quaternary ammonium monolithic column.

    Aly Saad Aly, Mohamed; Gauthier, Mario; Yeow, John

    2016-02-01

    Reusable antibacterial non-leaching monolithic columns polymerized in microfluidic channels designed for on-chip cell lysis applications were obtained by the photoinitiated free radical copolymerization of diallyldimethylammonium chloride (DADMAC) and ethylene glycol diacrylate (EGDA) in the presence of a porogenic solvent. The microfluidic channels were fabricated in cross-linked poly(methyl methacrylate) (X-PMMA) substrates by laser micromachining. The monolithic columns have the ability to inhibit the growth of, kill and efficiently lyse Gram-positive Micrococcus luteus (Schroeter) (ATCC 4698) and Kocuria rosea (ATCC 186), and Gram-negative bacteria Pseudomonas putida (ATCC 12633) and Escherichia coli (ATCC 35218) by mechanically shearing the bacterial membrane when forcing the cells to pass through the narrow pores of the monolithic column, and simultaneously disintegrating the cell membrane by physical contact with the antibacterial surface of the column. Cell lysis was confirmed by off-chip PCR without the need for further purification. The influence of the cross-linking monomer on bacterial growth inhibition, leaching, lysis efficiency of the monolithic column and its mechanical stability within the microfluidic channel were investigated and analyzed for three different cross-linking monomers: ethylene glycol dimethacrylate (EGDA), ethylene glycol dimethacrylate (EGDMA) and 1,6-hexanediol dimethacrylate (1,6-HDDMA). Furthermore, the bonding efficiency of two X-PMMA substrates with different cross-linking levels was studied. The monolithic columns were shown to be stable, non-leaching, and reusable for over 30 lysis cycles without significant performance degradation or DNA carryover when they were back-flushed between lysis cycles. PMID:26671610

  4. Survival of Microencapsulated Probiotic Bacteria after Processing and during Storage: A Review.

    Dianawati, Dianawati; Mishra, Vijay; Shah, Nagendra P

    2016-07-26

    The use of live probiotic bacteria as food supplement has become popular. Capability of probiotic bacteria to be kept at room temperature becomes necessary for customer's convenience and manufacturer's cost reduction. Hence, production of dried form of probiotic bacteria is important. Two common drying methods commonly used for microencapsulation are freeze drying and spray drying. In spite of their benefits, both methods have adverse effects on cell membrane integrity and protein structures resulting in decrease in bacterial viability. Microencapsulation of probiotic bacteria has been a promising technology to ensure bacterial stability during the drying process and to preserve their viability during storage without significantly losing their functional properties such acid tolerance, bile tolerance, surface hydrophobicity, and enzyme activities. Storage at room temperatures instead of freezing or low temperature storage is preferable for minimizing costs of handling, transportation, and storage. Concepts of water activity and glass transition become important in terms of determination of bacterial survival during the storage. The effectiveness of microencapsulation is also affected by microcapsule materials. Carbohydrate- and protein-based microencapsulants and their combination are discussed in terms of their protecting effect on probiotic bacteria during dehydration, during exposure to harsh gastrointestinal transit and small intestine transit and during storage. PMID:25853290

  5. Electrical lysis of cells for detergent-free droplet assays.

    de Lange, N; Tran, T M; Abate, A R

    2016-03-01

    Efficient lysis is critical when analyzing single cells in microfluidic droplets, but existing methods utilize detergents that can interfere with the assays to be performed. We demonstrate robust cell lysis without the use of detergents or other chemicals. In our method, cells are exposed to electric field immediately before encapsulation in droplets, resulting in cell lysis. We characterize lysis efficiency as a function of control parameters and demonstrate compatibility with enzymatic assays by measuring the catalysis of β-glucosidase, an important cellulase used in the conversion of biomass to biofuel. Our method enables assays in microfluidic droplets that are incompatible with detergents. PMID:27051471

  6. Estimates of bacterioplankton and Synechococcus spp. mortality from nanoflagellate grazing and viral lysis in the subtropical Danshui River estuary

    Tsai, An-Yi; Gong, Gwo-Ching; Huang, Yu Wen; Chao, Chien Fu

    2015-02-01

    To better understand picoplankton dynamics in the surface waters of upriver the Danshui River and its estuary, we assessed nanoflagellate-induced and virus-induced mortality of bacteria and Synechococcus spp. during different seasons (October, 2012 and January, April and July, 2013) using a modified dilution technique. Bacteria and viruses were significantly higher in abundance upriver than at the estuary. The distribution of Synechococcus spp. did not follow this spatial pattern. Abundance of Synechococcus spp. was relatively low during the whole sampling period in the upriver region. Furthermore, bacterial mortality resulting from nanoflagellate grazing were generally higher than those resulting from viral lysis in the upriver region, while Synechococcus spp. losses appeared to be mainly due to viral lysis upriver and in the estuary. Our dilution experiments suggested that nanoflagellates largely depend on bacteria as an important energy source there.

  7. Culture-independent detection of 'TM7' bacteria in a streptomycin-resistant acidophilic nitrifying process

    Nitrification in biological wastewater treatment processes has been believed for long time to take place under neutral conditions and is inhibited under acidic conditions. However, we previously constructed acidophilic nitrifying sequencing-batch reactors (ANSBRs) being capable of nitrification at −1 was added. In all reactors, the pH varied between 2.7 and 4.0, and ammonium was completely converted to nitrate in every batch cycle. PCR-aided denaturing gradient gel electrophoresis (DGGE) targeting 16S rRNA genes revealed that some major clones assigned to TM7 bacteria and Gammaproteobacteria were constantly present during the overall period of operation. Fluorescence in situ hybridization (FISH) with specific oligonucleotide probes also showed that TM7 bacteria predominated in all SRAN reactors, accounting for 58% of the total bacterial population on average. Although the biological significance of the TM7 bacteria in the SRAN reactors are unknown, our results suggest that these bacteria are possibly streptomycin-resistant and play some important roles in the acidophilic nitrifying process

  8. Microfluidic systems and methods for transport and lysis of cells and analysis of cell lysate

    Culbertson, Christopher T [Oak Ridge, TN; Jacobson, Stephen C [Knoxville, TN; McClain, Maxine A [Knoxville, TN; Ramsey, J Michael [Knoxville, TN

    2008-09-02

    Microfluidic systems and methods are disclosed which are adapted to transport and lyse cellular components of a test sample for analysis. The disclosed microfluidic systems and methods, which employ an electric field to rupture the cell membrane, cause unusually rapid lysis, thereby minimizing continued cellular activity and resulting in greater accuracy of analysis of cell processes.

  9. Inactivation of bacteria and helminth in wastewater treatment plant effluent using oxidation processes.

    Guadagnini, Regiane Aparecida; dos Santos, Luciana Urbano; Franco, Regina Maura Bueno; Guimarães, José Roberto

    2013-01-01

    The contamination of bodies of water by raw and even treated sewage is worrying because pathogens that affect public health and the environment are not fully eliminated in wastewater treatment systems. The disinfection step is an important barrier to adopt to reduce this contamination. However, widely used disinfectants such as chlorine do not guarantee the inactivation of resistant organisms such as spore-forming bacteria and helminth eggs. This study evaluated the effectiveness of processes of peroxidation (H2O2), ultraviolet radiation (UV) and peroxidation assisted by ultraviolet radiation (H2O2/UV) in terms of reduction and inactivation of total coliform bacteria, Escherichia coli, helminth eggs and larvae present in a treated sewage. Doses of UV radiation of 70 mJ cm(-2) and hydrogen peroxide concentration of 30 mg L(-1) were used. The number of bacteria reduced after UV and H2O2/UV processes was 3 and 4 log, respectively. An average reduction of 59% in the number of eggs was verified when using H2O2, UV, and H2O2/UV processes. Helminth larvae were reduced by 24% after H2O2 and UV; the process H2O2/UV did not reduce the number of larvae. Statistically significant differences between the processes for both organisms were not observed. PMID:24185066

  10. Drinking water biotic safety of particles and bacteria attached to fines in activated carbon process

    CHEN Wei; LIN Tao; WANG Leilei

    2007-01-01

    In this paper,the drinking water biotic safety of particles and bacteria attached to fines in activated carbon process was investigated by actual treatment process and advanced treatment pilot trial with granular activated carbon.In the experiment,the particles were detected by IBR particle calculating instrument,the activated carbon fines were counted on the basis of the most probable number (MPN) with a microscope,the total number of bacteria was analyzed between the conventional agar culture medium and the one with R2A,and the bacteria attached to activated carbon fines was resolved by the homogenization technique.The experimental results showed that the average total number of particles was 205 CNT/mL in the activated carbon effluent during a filter cycle,of which the number of particles with sizes>2μm was 77 CNT/mL more than the present particle control criterion of the American drinking water product standard (50 CNT/mL).The backwash of low density and long duration lowered particle number in the effluent.The MPN of activated carbon frees in the effluent was between 400 and 600 CNT/L,which accounted for less than 5‰ of the total particles from activated carbon filtration for a poor relative level (R2= 0.34).The microorganisms in activated carbon effluent consisted mostly of heterotrophic bacillus and the total bacteria number was five times as high as that of the inflow,i.e.the effluent from sand filter.The actual bacteria number may be truly indicated by the detection technique with R2A culture medium compared with the traditional agar cultivation.The inactivation efficiency of bacteria attached to activated carbon fines was less than 40% under 1.1 mg/L of chlorine contacting for 40 min.Results showed that the particles and bacteria attached to activated carbon fines may influence drinking water biotic safety,and that the effective control measures need to be further investigated.

  11. Statistical modelling of tropical cyclone tracks: modelling cyclone lysis

    Hall, T; Hall, Tim; Jewson, Stephen

    2005-01-01

    We describe results from the fifth stage of a project to build a statistical model of tropical cyclone tracks. The previous stages considered genesis and the shape of tracks. We now consider in more detail how to represent the lysis (death) of tropical cyclones. Improving the lysis model turns out to bring a significant improvement to the track model overall.

  12. First Experimental Results in Electrochemical Lysis of Thyroid Nodules

    A V Borsukov

    2009-03-01

    Full Text Available Electrochemical lysis is investigated to be used in miniinvasive treatment of thyroid nodules. Histological operative preparations of thyroid nodules (n = 20 helped to work out a model of electrochemical lysis optimal regimens. The results of this experiment were verified by usage of experimental animals.

  13. Dynamic monitoring of single cell lysis in an impedance-based microfluidic device.

    Zhou, Ying; Basu, Srinjan; Laue, Ernest D; Seshia, Ashwin A

    2016-08-01

    A microfluidic device that is capable of trapping and sensing dynamic variations in the electrical properties of individual cells is demonstrated. The device is applied to the real-time recording of impedance measurements of mouse embryonic stem cells (mESCs) during the process of membrane lysis, with the resulting changes in the electrical properties of cells during this process being quantitatively tracked over time. It is observed that the impedance magnitude decreases dramatically after cell membrane lysis. A significant shift in the phase spectrum is also observed during the time course of this process. By fitting experimental data to physical models, the electrical parameters of cells can be extracted and parameter variations quantified during the process. In the cell lysis experiments, the equivalent conductivity of the cell membrane is found to increase significantly due to pore formation in the membrane during lysis. An increase in the specific capacitance of the membrane is also observed. On the other hand, the conductivity of the cytoplasm is observed to decrease, which may be explained the fact that excess water enters the cell through the gradual permeabilization of the membrane during lysis. Cells can be trapped in the device for periods up to several days, and their electrical response can be monitored by real-time impedance measurements in a label-free and non-invasive manner. Furthermore, due to the highly efficient single cell trapping capacity of the device, a number of cells can be trapped and held in separate wells for concurrent parallel experiments, allowing for the possibility of stepped parametric experiments and studying cell heterogeneity by combining measurements across the array. PMID:27299468

  14. Study of the impact of environmental bacteria ob uranium speciation in order to engage bioremediation process

    Uranium is both a radiological and a chemical toxic. Its concentration in the environment is low except when human activities have caused pollution. Uranium is a heavy reactive element, and thus it is easily complexed with soil component like minerals or organic molecules. These different complexes can be more or less bioavailable for microorganisms and plants, and then get in the human food chain. The knowledge and the understanding of transfer mechanisms and also the fate of toxic elements in the biosphere are a key issue to estimate health and ecological hazards. The knowledge of the speciation is very important for bioremediation processes. Here, we focused on the microorganisms effects onto uranium speciation in environment. Bacteria can accumulate and/or transform uranium depending on the initial form of the element. Thus, its bioavailability could be changed. The species used in this work are Cupriavidus metallidurans CH34, which is an environmental bacteria with a high resistance to heavy metal, Deinococcus radiodurans R1, which is known for his radiological resistance, and Rhodopseudomonas palustris, which is a purple photo-trophic bacteria capable of degrading aromatic compounds. Two forms of uranium were used with these bacteria, a mineral one, uranyl carbonate, and an organic one, uranyl citrate. In a first step, the growth media were modified in order to stabilize uranium complexes thanks to a simulation program. Then, the capacity of the bacteria to accumulate or transform uranium was studied. We saw a difference between minimal inhibition concentrations of these two speciation which is due to a difference between phosphate bioavailability. No accumulation was observed with environmental pH but uranium precipitation was observed with acidic pH (pH 1). Uranium speciation seemed to be well controlled in the growth media and the precipitates were uranyl phosphate. (author)

  15. Fate of antibiotic resistant cultivable heterotrophic bacteria and antibiotic resistance genes in wastewater treatment processes.

    Zhang, Songhe; Han, Bing; Gu, Ju; Wang, Chao; Wang, Peifang; Ma, Yanyan; Cao, Jiashun; He, Zhenli

    2015-09-01

    Antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are emerging contaminants of environmental concern. Heterotrophic bacteria in activated sludge have an important role in wastewater treatment plants (WWTPs). However, the fate of cultivable heterotrophic ARB and ARGs in WWPTs process remains unclear. In the present study, we investigated the antibiotic-resistant phenotypes of cultivable heterotrophic bacteria from influent and effluent water of three WWTPs and analysed thirteen ARGs in ARB and in activated sludge from anoxic, anaerobic and aerobic compartments. From each influent or effluent sample of the three plants, 200 isolates were randomly tested for susceptibility to 12 antibiotics. In these samples, between 5% and 64% isolates showed resistance to >9 antibiotics and the proportion of >9-drug-resistant bacteria was lower in isolates from effluent than from influent. Eighteen genera were identified in 188 isolates from influent (n=94) and effluent (n=94) of one WWTP. Six genera (Aeromonas, Bacillus, Lysinibacillus, Microbacterium, Providencia, and Staphylococcus) were detected in both influent and effluent samples. Gram-negative and -positive isolates dominated in influent and effluent, respectively. The 13 tetracycline-, sulphonamide-, streptomycin- and β-lactam-resistance genes were detected at a higher frequency in ARB from influent than from effluent, except for sulA and CTX-M, while in general, the abundances of ARGs in activated sludge from two of the three plants were higher in aerobic compartments than in anoxic ones, indicating abundant ARGs exit in the excess sledges and/or in uncultivable bacteria. These findings may be useful for elucidating the effect of WWTP on ARB and ARGs. PMID:25950407

  16. Halotolerant bacteria in the São Paulo Zoo composting process and their hydrolases and bioproducts.

    Oliveira, Lilian C G; Ramos, Patricia Locosque; Marem, Alyne; Kondo, Marcia Y; Rocha, Rafael C S; Bertolini, Thiago; Silveira, Marghuel A V; da Cruz, João Batista; de Vasconcellos, Suzan Pantaroto; Juliano, Luiz; Okamoto, Debora N

    2015-06-01

    Halophilic microorganisms are able to grow in the presence of salt and are also excellent source of enzymes and biotechnological products, such as exopolysaccharides (EPSs) and polyhydroxyalkanoates (PHAs). Salt-tolerant bacteria were screened in the Organic Composting Production Unit (OCPU) of São Paulo Zoological Park Foundation, which processes 4 ton/day of organic residues including plant matter from the Atlantic Rain Forest, animal manure and carcasses and mud from water treatment. Among the screened microorganisms, eight halotolerant bacteria grew at NaCl concentrations up to 4 M. These cultures were classified based on phylogenetic characteristics and comparative partial 16S rRNA gene sequence analysis as belonging to the genera Staphylococcus, Bacillus and Brevibacterium. The results of this study describe the ability of these halotolerant bacteria to produce some classes of hydrolases, namely, lipases, proteases, amylases and cellulases, and biopolymers. The strain characterized as of Brevibacterium avium presented cellulase and amylase activities up to 4 M NaCl and also produced EPSs and PHAs. These results indicate the biotechnological potential of certain microorganisms recovered from the composting process, including halotolerant species, which have the ability to produce enzymes and biopolymers, offering new perspectives for environmental and industrial applications. PMID:26273248

  17. Halotolerant bacteria in the São Paulo Zoo composting process and their hydrolases and bioproducts

    Lilian C.G. Oliveira

    2015-06-01

    Full Text Available Halophilic microorganisms are able to grow in the presence of salt and are also excellent source of enzymes and biotechnological products, such as exopolysaccharides (EPSs and polyhydroxyalkanoates (PHAs. Salt-tolerant bacteria were screened in the Organic Composting Production Unit (OCPU of São Paulo Zoological Park Foundation, which processes 4 ton/day of organic residues including plant matter from the Atlantic Rain Forest, animal manure and carcasses and mud from water treatment. Among the screened microorganisms, eight halotolerant bacteria grew at NaCl concentrations up to 4 M. These cultures were classified based on phylogenetic characteristics and comparative partial 16S rRNA gene sequence analysis as belonging to the genera Staphylococcus, Bacillus and Brevibacterium. The results of this study describe the ability of these halotolerant bacteria to produce some classes of hydrolases, namely, lipases, proteases, amylases and cellulases, and biopolymers. The strain characterized as of Brevibacterium avium presented cellulase and amylase activities up to 4 M NaCl and also produced EPSs and PHAs. These results indicate the biotechnological potential of certain microorganisms recovered from the composting process, including halotolerant species, which have the ability to produce enzymes and biopolymers, offering new perspectives for environmental and industrial applications.

  18. Lysis delay and burst shrinkage of coliphage T7 by deletion of terminator Tφ reversed by deletion of early genes.

    Nguyen, Huong Minh; Kang, Changwon

    2014-02-01

    Bacteriophage T7 terminator Tϕ is a class I intrinsic terminator coding for an RNA hairpin structure immediately followed by oligo(U), which has been extensively studied in terms of its transcription termination mechanism, but little is known about its physiological or regulatory functions. In this study, using a T7 mutant phage, where a 31-bp segment of Tϕ was deleted from the genome, we discovered that deletion of Tϕ from T7 reduces the phage burst size but delays lysis timing, both of which are disadvantageous for the phage. The burst downsizing could directly result from Tϕ deletion-caused upregulation of gene 17.5, coding for holin, among other Tϕ downstream genes, because infection of gp17.5-overproducing Escherichia coli by wild-type T7 phage showed similar burst downsizing. However, the lysis delay was not associated with cellular levels of holin or lysozyme or with rates of phage adsorption. Instead, when allowed to evolve spontaneously in five independent adaptation experiments, the Tϕ-lacking mutant phage, after 27 or 29 passages, recovered both burst size and lysis time reproducibly by deleting early genes 0.5, 0.6, and 0.7 of class I, among other mutations. Deletion of genes 0.5 to 0.7 from the Tϕ-lacking mutant phage decreased expression of several Tϕ downstream genes to levels similar to that of the wild-type phage. Accordingly, phage T7 lysis timing is associated with cellular levels of Tϕ downstream gene products. This suggests the involvement of unknown factor(s) besides the known lysis proteins, lysozyme and holin, and that Tϕ plays a role of optimizing burst size and lysis time during T7 infection. IMPORTANCE Bacteriophages are bacterium-infecting viruses. After producing numerous progenies inside bacteria, phages lyse bacteria using their lysis protein(s) to get out and start a new infection cycle. Normally, lysis is tightly controlled to ensure phage progenies are maximally produced and released at an optimal time. Here, we have

  19. A Cell Lysis and Protein Purification - Single Molecule Assay Devices for Evaluation of Genetically Engineered Proteins

    Nakyama, Tetsuya; Tabata, Kazuhito; Noji, Hiroyuki; Yokokawa, Ryuji

    We have developed two devices applicable to evaluate genetically engineered proteins in single molecule assay: on-chip cell lysis device, and protein purification - assay device. A motor protein, F1-ATPase expressed in E.coli, was focused in this report as a target protein. Cell lysis was simply performed by applying pulse voltage between Au electrodes patterned by photolithography, and its efficiency was determined by absorptiometry. The subsequent processes, purification and assay of extracted proteins, were demonstrated in order to detect F1-ATPase and to evaluate its activity. The specific bonding between his-tag in F1-ATPase and Ni-NTA coated on a glass surface was utilized for the purification process. After immobilization of F1-ATPase, avidin-coated microspheres and adenosine tri-phosphate (ATP) solution were infused sequentially to assay the protein. Microsphere rotation was realized by activity of F1-ATPase corresponding to ATP hydrolysis. Results show that the cell lysis device, at the optimum condition, extracts enough amount of protein for single molecule assay. Once cell lysate was injected to the purification - assay device, proteins were diffused in the lateral direction in a Y-shape microchannel. The gradient of protein concentratioin provides an optimal concentration for the assay i.e. the highest density of rotating beads. Density of rotating beads is also affected by the initial concentration of protein injected to the device. The optimum concentration was achieved by our cell lysis device not by the conventional method by ultrasonic wave. Rotation speed was analyzed for several microspheres assayed in the purification - assay device, and the results were compatible to that of conventional assay in which F1-ATPase was purified in bulk scale. In conclusion, we have demonstrated on-chip cell lysis and assay appropriate for the sequential analysis without any pretreatment. On-chip devices replacing conventional bioanalytical methods will be

  20. Coexistence of Lactic Acid Bacteria and Potential Spoilage Microbiota in a Dairy Processing Environment.

    Stellato, Giuseppina; De Filippis, Francesca; La Storia, Antonietta; Ercolini, Danilo

    2015-11-01

    Microbial contamination in food processing plants can play a fundamental role in food quality and safety. In this study, the microbiota in a dairy plant was studied by both 16S rRNA- and 26S rRNA-based culture-independent high-throughput amplicon sequencing. Environmental samples from surfaces and tools were studied along with the different types of cheese produced in the same plant. The microbiota of environmental swabs was very complex, including more than 200 operational taxonomic units with extremely variable relative abundances (0.01 to 99%) depending on the species and sample. A core microbiota shared by 70% of the samples indicated a coexistence of lactic acid bacteria with a remarkable level of Streptococcus thermophilus and possible spoilage-associated bacteria, including Pseudomonas, Acinetobacter, and Psychrobacter, with a relative abundance above 50%. The most abundant yeasts were Kluyveromyces marxianus, Yamadazyma triangularis, Trichosporon faecale, and Debaryomyces hansenii. Beta-diversity analyses showed a clear separation of environmental and cheese samples based on both yeast and bacterial community structure. In addition, predicted metagenomes also indicated differential distribution of metabolic pathways between the two categories of samples. Cooccurrence and coexclusion pattern analyses indicated that the occurrence of potential spoilers was excluded by lactic acid bacteria. In addition, their persistence in the environment can be helpful to counter the development of potential spoilers that may contaminate the cheeses, with possible negative effects on their microbiological quality. PMID:26341209

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

    Juliana Pacheco da Rosa

    2013-01-01

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

  2. Squamous cell carcinoma complicating an hereditary epidermo-lysis bullosa

    The dystrophic form of hereditary epidermo-lysis bullosa is associated with an increased frequency of squamous cell carcinoma. We report a new case. An 18-year-old patient, carrying a Hallopeau Siemens hereditary epidermo-lysis bullosa, presented a subcutaneous nodular lesion, for 1 year that ulcerated and budded with inguinal lymphadenopathy. The histological study ted to the conclusion of a well differentiated squamous cell carcinoma. The patient was treated surgically. Tumor and metastatic lymph nodes were excised. A radiotherapy was decided but the postoperative course was fatal due to an infection and to a deterioration of her general condition. Squamous cell carcinoma frequently occurs on the cicatricial lesion of hereditary epidermo-lysis bullosa and usually affects males with recessive hereditary epidermo-lysis bullosa. Metastases are frequent, precocious and multiple. The treatment may be surgical. The particularities of our observation are the young age of patient and the localization. (author)

  3. Photosynthetic bacteria production from food processing wastewater in sequencing batch and membrane photo-bioreactors.

    Chitapornpan, S; Chiemchaisri, C; Chiemchaisri, W; Honda, R; Yamamoto, K

    2012-01-01

    Application of photosynthetic process could be highly efficient and surpass anaerobic treatment in releasing less greenhouse gas and odor while the biomass produced can be utilized. The combination of photosynthetic process with membrane separation is possibly effective for water reclamation and biomass production. In this study, cultivation of mixed culture photosynthetic bacteria from food processing wastewater was investigated in a sequencing batch reactor (SBR) and a membrane bioreactor (MBR) supplied with infrared light. Both photo-bioreactors were operated at a hydraulic retention time (HRT) of 10 days. Higher MLSS concentration achieved in the MBR through complete retention of biomass resulted in a slightly improved performance. When the system was operated with MLSS controlled by occasional sludge withdrawal, total biomass production of MBR and SBR photo-bioreactor was almost equal. However, 64.5% of total biomass production was washed out with the effluent in SBR system. Consequently, the higher biomass could be recovered for utilization in MBR. PMID:22258682

  4. Continuous cell lysis in microfluidics through acoustic and optoelectronic tweezers

    Witte, C.; Kremer, C; Cooper, J.M.; Neale, S.L.

    2013-01-01

    A versatile platform for efficient cell lysis using a combination of acoustic and electric fields in a microchannel is presented. Cell membrane disruption is triggered by electric fields inducing electroporation and then lysis. The principle of optoelectronic tweezers (OET) is applied to control the electric field strength and a surface acoustic wave transducer is attached to an OET chip to implement acoustic tweezing (AT). The system is characterized in terms of spatial contro...

  5. Acute tumor lysis syndrome after proximal splenic artery embolization

    Jason T. Salsamendi; Mehul H. Doshi; Francisco J. Gortes; Levi, Joe U; Govindarajan Narayanan

    2016-01-01

    Preoperative splenic artery embolization for massive splenomegaly has been shown to reduce intraoperative hemorrhage during splenectomy. We describe a case of tumor lysis syndrome after proximal splenic artery embolization in a patient with advanced mantle cell lymphoma and splenic involvement. The patient presented initially with hyperkalemia two days after embolization that worsened during splenectomy. He was stabilized, but developed laboratory tumor lysis syndrome with renal failure and e...

  6. Defensins promote fusion and lysis of negatively charged membranes.

    Fujii, G; Selsted, M E; Eisenberg, D.

    1993-01-01

    Defensins, a family of cationic peptides isolated from mammalian granulocytes and believed to permeabilize membranes, were tested for their ability to cause fusion and lysis of liposomes. Unlike alpha-helical peptides whose lytic effects have been extensively studied, the defensins consist primarily of beta-sheet. Defensins fuse and lyse negatively charged liposomes but display reduced activity with neutral liposomes. These and other experiments suggest that fusion and lysis is mediated prima...

  7. Biotransformation of pharmaceuticals by ammonia oxidizing bacteria in wastewater treatment processes.

    Xu, Yifeng; Yuan, Zhiguo; Ni, Bing-Jie

    2016-10-01

    Pharmaceutical residues could potentially pose detrimental effects on aquatic ecosystems and human health, with wastewater treatment being one of the major pathways for pharmaceuticals to enter into the environment. Enhanced removal of pharmaceuticals by ammonia oxidizing bacteria (AOB) has been widely observed in wastewater treatment processes. This article reviews the current knowledge on the biotransformation of pharmaceuticals by AOB. The relationship between the pharmaceuticals removal and nitrification process was revealed. The important role of AOB-induced cometabolism on the biotransformation of pharmaceuticals as well as their transformation products and pathways was elucidated. Kinetics and mathematical models describing the biotransformation of pharmaceuticals by AOB were also reviewed. The results highlighted the high degradation capabilities of AOB toward some refractory pharmaceuticals, with their degradations being clearly related to the nitrification rate and their transformation products being identified, which may exhibit similar or higher ecotoxicological impacts compared to the parent compound. PMID:27243932

  8. Extraction of plasmid DNA using reactor scale alkaline lysis and selective precipitation for scalable transient transfection

    Wright, Jason L.; Jordan, Martin; Wurm, Florian M.

    2001-01-01

    DNA extracted and purified for vaccination, gene therapy or transfection of cultured cells has to meet different criteria. We describe herein, a scalable process for the primary extraction of plasmid DNA suitable for transient expression of recombinant protein. We focus on the scale up of alkaline lysis for the extraction of plasmid DNA from Escherichia coli, and use a simple stirred tank reactor system to achieve this. By adding a series of three precipitations (including a selective precipi...

  9. The Increasing Interest of ANAMMOX Research in China: Bacteria, Process Development, and Application

    Mohammad Ali

    2013-01-01

    Full Text Available Nitrogen pollution created severe environmental problems and increasingly has become an important issue in China. Since the first discovery of ANAMMOX in the early 1990s, this related technology has become a promising as well as sustainable bioprocess for treating strong nitrogenous wastewater. Many Chinese research groups have concentrated their efforts on the ANAMMOX research including bacteria, process development, and application during the past 20 years. A series of new and outstanding outcomes including the discovery of new ANAMMOX bacterial species (Brocadia sinica, sulfate-dependent ANAMMOX bacteria (Anammoxoglobus sulfate and Bacillus benzoevorans, and the highest nitrogen removal performance (74.3–76.7 kg-N/m3/d in lab scale granule-based UASB reactors around the world were achieved. The characteristics, structure, packing pattern and floatation mechanism of the high-rate ANAMMOX granules in ANAMMOX reactors were also carefully illustrated by native researchers. Nowadays, some pilot and full-scale ANAMMOX reactors were constructed to treat different types of ammonium-rich wastewater including monosodium glutamate wastewater, pharmaceutical wastewater, and leachate. The prime objective of the present review is to elucidate the ongoing ANAMMOX research in China from lab scale to full scale applications, comparative analysis, and evaluation of significant findings and to set a design to usher ANAMMOX research in culmination.

  10. Monitoring exogenous and indigenous bacteria by PCR-DGGE technology during the process of microbial enhanced oil recovery.

    Wang, Jun; Ma, Ting; Zhao, Lingxia; Lv, Jinghua; Li, Guoqiang; Zhang, Hao; Zhao, Ben; Liang, Fenglai; Liu, Rulin

    2008-06-01

    A field experiment was performed to monitor changes in exogenous bacteria and to investigate the diversity of indigenous bacteria during a field trial of microbial enhanced oil recovery (MEOR). Two wells (26-195 and 27-221) were injected with three exogenous strains and then closed to allow for microbial growth and metabolism. After a waiting period, the pumps were restarted and the samples were collected. The bacterial populations of these samples were analyzed by denaturing gradient gel electrophoresis (DGGE) with PCR-amplified 16S rRNA fragments. DGGE profiles indicated that the exogenous strains were retrieved in the production water samples and indigenous strains could also be detected. After the pumps were restarted, average oil yield increased to 1.58 and 4.52 tons per day in wells 26-195 and 27-221, respectively, compared with almost no oil output before the injection of exogenous bacteria. Exogenous bacteria and indigenous bacteria contributed together to the increased oil output. Sequence analysis of the DGGE bands revealed that Proteobacteria were a major component of the predominant bacteria in both wells. Changes in the bacteria population in the reservoirs during MEOR process were monitored by molecular analysis of the 16S rRNA gene sequence. DGGE analysis was a successful approach to investigate the changes in microorganisms used for enhancing oil recovery. The feasibility of MEOR technology in the petroleum industry was also demonstrated. PMID:18273653

  11. Direct cell lysis for single-cell gene expression profiling

    DavidSvec

    2013-11-01

    Full Text Available The interest to analyze single and few cell samples is rapidly increasing. Numerous extraction protocols to purify nucleic acids are available, but most of them compromise severely on yield to remove contaminants and are therefore not suitable for the analysis of samples containing small numbers of transcripts only. Here, we evaluate 17 direct cell lysis protocols for transcript yield and compatibility with downstream reverse transcription quantitative real-time PCR. Four endogenously expressed genes are assayed together with RNA and DNA spikes in the samples. We found bovine serum albumin (BSA to be the best lysis agent, resulting in efficient cell lysis, high RNA stability and enhanced reverse transcription efficiency. Furthermore, we found direct cell lysis with BSA superior to standard column based extraction methods, when analyzing from 1 up to 512 mammalian cells. In conclusion, direct cell lysis protocols based on BSA can be applied with most cell collection methods and are compatible with most analytical workflows to analyze single cells as well as samples composed of small numbers of cells.

  12. Performance and dye-degrading bacteria isolation of a hybrid membrane process

    Textile dyeing wastewater contains harmful compounds, which are toxic to both marine organisms and human beings if it discharged into an aquatic environmental without suitable treatment. In this study, the wastewater containing the azo dye, Reactive Black 5 (RB5), was partially treated in an anaerobic sequencing batch reactor which was further treated either in an aerobic membrane bioreactors (AOMBR) or in combined aerobic membrane bioreactor/reverse osmosis (AOMBR/RO) process. The results showed that in the anaerobic sequencing batch reactor the RB5 dye was degraded to form aromatic amine intermediate metabolites, which were further mineralized in the AOMBR. It was also observed that although all effluents from the AOMBR and AOMBR/RO processes met the Taiwan EPA's effluent criteria, irrespective of which membranes were used in the aerobic tank, the effluent from the AOMBR/RO process met the criteria for reuse for toilet flushing, landscaping, irrigation, and cooling water purposes, where as the AOMBR effluent only met the criteria for cooling water due to incomplete color removal. Five anaerobic high dye-degrading bacteria were isolated, which were identified to be the same species of Lactococcus lactis by 16S rRNA sequencing. The L. lactis showed complete degradation of RB5 and further studies showed that it can also able to degrade Reactive Red 120 and Reactive Yellow 84 efficiently within 6 h.

  13. Process for Generation of Hydrogen Gas from Various Feedstocks Using Thermophilic Bacteria

    Ooteghem Van, Suellen

    2005-09-13

    A method for producing hydrogen gas is provided comprising selecting a bacteria from the Order Thermotogales, subjecting the bacteria to a feedstock and to a suitable growth environment having an oxygen concentration below the oxygen concentration of water in equilibrium with air; and maintaining the environment at a predetermined pH and at a temperature of at least approximately 45 degrees C. for a time sufficient to allow the bacteria to metabolize the feedstock.

  14. A mathematical model for expected time to extinction of pathogenic bacteria through antibiotic

    Ghosh, M. K.; Nandi, S.; Roy, P. K.

    2016-04-01

    Application of antibiotics in human system to prevent bacterial diseases like Gastritis, Ulcers, Meningitis, Pneumonia and Gonorrhea are indispensable. Antibiotics saved innumerable lives and continue to be a strong support for therapeutic application against pathogenic bacteria. In human system, bacterial diseases occur when pathogenic bacteria gets into the body and begin to reproduce and crowd out healthy bacteria. In this process, immature bacteria releases enzyme which is essential for bacterial cell-wall biosynthesis. After complete formation of cell wall, immature bacteria are converted to mature or virulent bacteria which are harmful to us during bacterial infections. Use of antibiotics as drug inhibits the bacterial cell wall formation. After application of antibiotics within body, the released bacterial enzyme binds with antibiotic molecule instead of its functional site during the cell wall synthesis in a competitive inhibition approach. As a consequence, the bacterial cell-wall formation as well as maturation process of pathogenic bacteria is halted and the disease is cured with lysis of bacterial cells. With this idea, a mathematical model has been developed in the present research investigation to review the inhibition of biosynthesis of bacterial cell wall by the application of antibiotics as drug in the light of enzyme kinetics. This approach helps to estimate the expected time to extinction of the pathogenic bacteria. Our mathematical approach based on the enzyme kinetic model for finding out expected time to extinction contributes favorable results for understanding of disease dynamics. Analytical and numerical results based on simulated findings validate our mathematical model.

  15. Detecting cell lysis using viscosity monitoring in E. coli fermentation to prevent product loss.

    Newton, Joseph M; Schofield, Desmond; Vlahopoulou, Joanna; Zhou, Yuhong

    2016-07-01

    Monitoring the physical or chemical properties of cell broths to infer cell status is often challenging due to the complex nature of the broth. Key factors indicative of cell status include cell density, cell viability, product leakage, and DNA release to the fermentation broth. The rapid and accurate prediction of cell status for hosts with intracellular protein products can minimise product loss due to leakage at the onset of cell lysis in fermentation. This article reports the rheological examination of an industrially relevant E. coli fermentation producing antibody fragments (Fab'). Viscosity monitoring showed an increase in viscosity during the exponential phase in relation to the cell density increase, a relatively flat profile in the stationary phase, followed by a rapid increase which correlated well with product loss, DNA release and loss of cell viability. This phenomenon was observed over several fermentations that a 25% increase in broth viscosity (using induction-point viscosity as a reference) indicated 10% product loss. Our results suggest that viscosity can accurately detect cell lysis and product leakage in postinduction cell cultures, and can identify cell lysis earlier than several other common fermentation monitoring techniques. This work demonstrates the utility of rapidly monitoring the physical properties of fermentation broths, and that viscosity monitoring has the potential to be a tool for process development to determine the optimal harvest time and minimise product loss. © 2016 The Authors. Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers, 32:1069-1076, 2016. PMID:27111912

  16. Role of Protein Phosphorylation in the Regulation of Cell Cycle and DNA-Related Processes in Bacteria

    Garcia-Garcia, Transito; Poncet, Sandrine; Derouiche, Abderahmane;

    2016-01-01

    replication during the cell cycle, as well as in the mechanisms that cope with stress-induced replication blocks. Similar to eukaryotes, bacteria use Hanks-type kinases and phosphatases for signal transduction, and protein phosphorylation is involved in numerous cellular processes. However, it remains unclear...... whether protein phosphorylation in bacteria can also regulate the activity of proteins involved in DNA-mediated processes such as DNA replication or repair. Accumulating evidence supported by functional and biochemical studies suggests that phospho-regulatory mechanisms also take place during the...

  17. Co-evolution of tRNA 3′ trailer sequences with 3′ processing enzymes in bacteria

    Li, Zhongwei; Gong, Xin; JOSHI, VEDANG H.; LI, MUXIN

    2005-01-01

    Maturation of the tRNA 3′ terminus is a complicated process in bacteria. Usually, it is initiated by an endonucleolytic cleavage carried out by RNase E and Z in different bacteria. In Escherichia coli, RNase E cleaves AU-rich sequences downstream of tRNA, producing processing intermediates with a few extra residues at the 3′ end; these are then removed by exoribonuclease trimming to generate the mature 3′ end. Here we show that essentially all E. coli tRNA precursors contain a potential RNase...

  18. The Presence of Mercury Resistant Bacteria in Sediment of Gold Processing Plant at Waekerta Village of Buru District, Maluku Province and their Activity in Reducing Mercury

    Sarmawaty Kotala; Retno Kawuri; Ida Bagus Wayan Gunam

    2014-01-01

    Mercury was one of the heavy metal polute in environment and had the toxic characteristic to the living creatures. Golden mining in Waeapo subdistrict used mercury to extract the gold and exile the waste to the environment freely. Several precedented research showed that waste sediment of gold processing contains mercury resistance bacteria. Mercury resistance bacteria can be used as bioremediation agent because those bacteria can reduce mercury. Mercury resistance bacteria has mer operon w...

  19. Synergies of carvacrol and 1,8-cineole to inhibit bacteria associated with minimally processed vegetables.

    de Sousa, Jossana Pereira; de Azerêdo, Geíza Alves; de Araújo Torres, Rayanne; da Silva Vasconcelos, Margarida Angélica; da Conceição, Maria Lúcia; de Souza, Evandro Leite

    2012-03-15

    This study assessed the occurrence of an enhancing inhibitory effect of the combined application of carvacrol and 1,8-cineole against bacteria associated with minimally processed vegetables using the determination of Fractional Inhibitory Concentration (FIC) index, time-kill assay in vegetable broth and application in vegetable matrices. Their effects, individually and in combination, on the sensory characteristics of the vegetables were also determined. Carvacrol and 1,8-cineole displayed Minimum Inhibitory Concentration (MIC) in a range of 0.6-2.5 and 5-20 μL/mL, respectively, against the organisms studied. FIC indices of the combined application of the compounds were 0.25 against Listeria monocytogenes, Aeromonas hydrophila and Pseudomonas fluorescens, suggesting a synergic interaction. Application of carvacrol and 1,8-cineole alone (MIC) or in a mixture (1/8 MIC+1/8 MIC or 1/4 MIC+1/4 MIC) in vegetable broth caused a significant decrease (pvegetable broth and in experimentally inoculated fresh-cut vegetables. A similar efficacy was observed in the reduction of naturally occurring microorganisms in vegetables. Sensory evaluation revealed that the scores of the most-evaluated attributes fell between "like slightly" and "neither like nor dislike." The combination of carvacrol and 1,8-cineole at sub-inhibitory concentrations could constitute an interesting approach to sanitizing minimally processed vegetables. PMID:22273461

  20. Phenols in anaerobic digestion processes and inhibition of ammonia oxidising bacteria (AOB) in soil

    This study focuses on the presence of phenols in digestate from seven Swedish large-scale anaerobic digestion processes and their impact on the activity of ammonia oxidising bacteria (AOB) in soil. In addition, the importance of feedstock composition and phenol degradation capacity for the occurrence of phenols in the digestate was investigated in the same processes. The results revealed that the content of phenols in the digestate was related to the inhibition of the activity of AOB in soil (EC5 = 26 μg phenols g-1 d.w. soil). In addition, five pure phenols (phenol, o-, p-, m-cresol and 4-ethylphenol) inhibited the AOB to a similar extent (EC5 = 43-110 μg g-1 d.w. soil). The phenol content in the digestate was mainly dependent on the composition of the feedstock, but also to some extent by the degradation capacity in the anaerobic digestion process. Swine manure in the feedstock resulted in digestate containing higher amounts of phenols than digestate from reactors with less or no swine manure in the feedstock. The degradation capacity of phenol and p-cresol was studied in diluted small-scale batch cultures and revealed that anaerobic digestion at mesophilic temperatures generally exhibited a higher degradation capacity compared to digestion at thermophilic temperature. Although phenol, p-cresol and 4-ethylphenol were quickly degraded in soil, the phenols added with the digestate constitute an environmental risk according to the guideline values for contaminated soils set by the Swedish Environmental Protection Agency. In conclusion, the management of anaerobic digestion processes is of decisive importance for the production of digestate with low amounts of phenols, and thereby little risks for negative effects of the phenols on the soil ecosystem

  1. Culture-independent detection of 'TM7' bacteria in a streptomycin-resistant acidophilic nitrifying process

    Kurogi, T.; Linh, N. T. T.; Kuroki, T.; Yamada, T. [Department of Environmental and Life Science, Toyohashi University of Technology, Toyohashi 441-8580 (Japan); Hiraishi, A. [Department of Environmental and Life Science, Toyohashi University of Technology, Toyohashi 441-8580, Japan and Electronics-inspired Interdisciplinary Institute (EIIRIS), Toyohashi University of Technology, Toyohashi 441-8580 (Japan)

    2014-02-20

    Nitrification in biological wastewater treatment processes has been believed for long time to take place under neutral conditions and is inhibited under acidic conditions. However, we previously constructed acidophilic nitrifying sequencing-batch reactors (ANSBRs) being capable of nitrification at < pH 4 and harboring bacteria of the candidate phylum 'TM7' as the major constituents of the microbial community. In light of the fact that the 16S rRNA of TM7 bacteria has a highly atypical base substitution possibly responsible for resistance to streptomycin at the ribosome level, this study was undertaken to construct streptomycin-resistant acidophilic nitrifying (SRAN) reactors and to demonstrate whether TM7 bacteria are abundant in these reactors. The SRAN reactors were constructed by seeding with nitrifying sludge from an ANSBR and cultivating with ammonium-containing mineral medium (pH 4.0), to which streptomycin at a concentration of 10, 30 and 50 mg L{sup −1} was added. In all reactors, the pH varied between 2.7 and 4.0, and ammonium was completely converted to nitrate in every batch cycle. PCR-aided denaturing gradient gel electrophoresis (DGGE) targeting 16S rRNA genes revealed that some major clones assigned to TM7 bacteria and Gammaproteobacteria were constantly present during the overall period of operation. Fluorescence in situ hybridization (FISH) with specific oligonucleotide probes also showed that TM7 bacteria predominated in all SRAN reactors, accounting for 58% of the total bacterial population on average. Although the biological significance of the TM7 bacteria in the SRAN reactors are unknown, our results suggest that these bacteria are possibly streptomycin-resistant and play some important roles in the acidophilic nitrifying process.

  2. Sulfate reducing bacteria and their activities in oil sands process-affected water biofilm

    Biofilm reactors were constructed to grow stratified multispecies biofilm in oil sands process-affected water (OSPW) supplemented with growth medium. The development of sulfate reducing bacteria (SRB) within the biofilm and the biofilm treatment of OSPW were evaluated. The community structure and potential activity of SRB in the biofilm were investigated with H2S microsensor measurements, dsrB gene-based denaturing gradient gel electrophoresis (DGGE), and the real time quantitative polymerase chain reaction (qPCR). Multispecies biofilm with a thickness of 1000 μm was successfully developed on engineered biocarriers. H2S production was observed in the deeper anoxic zone of the biofilm from around 750 μm to 1000 μm below the bulk water-biofilm interface, revealing sulfate reduction in the deeper zone of the stratified biofilm. The biofilm removed chemical oxygen demand (COD), sulfate, and nitrogen. The study expands current knowledge of biofilm treatment of OSPW and the function of anaerobic SRB in OSPW biofilm, and thus provides information for future bioreactor development in the reclamation of OSPW. - Graphical abstract: The development of sulfate reducing bacteria (SRB) within Oil Sands Process-affected Water (OSPW) biofilm and the biofilm treatment of OSPW were evaluated by Liu and coworkers. Combined microsensor and molecular biology techniques were utilized in this study. Their results demonstrated that multispecies biofilm with a thickness of 1000 μm was successfully developed on engineered biocarriers. H2S production was observed in the deeper anoxic zone of the biofilm from around 750 μm to 1000 μm below the bulk water-biofilm interface, revealing sulfate reduction in the deeper zone of the biofilm. The biofilm removed chemical oxygen demand (COD), sulfate, and nitrogen. - Highlights: • Biofilm in oil sands wastewater was developed on engineered biocarriers. • Bacterial community and in situ activity of SRB were studied in the biofilm. • Sulfate

  3. Sulfate reducing bacteria and their activities in oil sands process-affected water biofilm

    Liu, Hong; Yu, Tong, E-mail: tong.yu@ualberta.ca; Liu, Yang, E-mail: yang.liu@ualberta.ca

    2015-12-01

    Biofilm reactors were constructed to grow stratified multispecies biofilm in oil sands process-affected water (OSPW) supplemented with growth medium. The development of sulfate reducing bacteria (SRB) within the biofilm and the biofilm treatment of OSPW were evaluated. The community structure and potential activity of SRB in the biofilm were investigated with H{sub 2}S microsensor measurements, dsrB gene-based denaturing gradient gel electrophoresis (DGGE), and the real time quantitative polymerase chain reaction (qPCR). Multispecies biofilm with a thickness of 1000 μm was successfully developed on engineered biocarriers. H{sub 2}S production was observed in the deeper anoxic zone of the biofilm from around 750 μm to 1000 μm below the bulk water-biofilm interface, revealing sulfate reduction in the deeper zone of the stratified biofilm. The biofilm removed chemical oxygen demand (COD), sulfate, and nitrogen. The study expands current knowledge of biofilm treatment of OSPW and the function of anaerobic SRB in OSPW biofilm, and thus provides information for future bioreactor development in the reclamation of OSPW. - Graphical abstract: The development of sulfate reducing bacteria (SRB) within Oil Sands Process-affected Water (OSPW) biofilm and the biofilm treatment of OSPW were evaluated by Liu and coworkers. Combined microsensor and molecular biology techniques were utilized in this study. Their results demonstrated that multispecies biofilm with a thickness of 1000 μm was successfully developed on engineered biocarriers. H{sub 2}S production was observed in the deeper anoxic zone of the biofilm from around 750 μm to 1000 μm below the bulk water-biofilm interface, revealing sulfate reduction in the deeper zone of the biofilm. The biofilm removed chemical oxygen demand (COD), sulfate, and nitrogen. - Highlights: • Biofilm in oil sands wastewater was developed on engineered biocarriers. • Bacterial community and in situ activity of SRB were studied in the

  4. Interspecies interactions result in enhanced biofilm formation by co-cultures of bacteria isolated from a food processing environment

    Røder, Henriette Lyng; Raghupathi, Prem Krishnan; Herschend, Jakob;

    2015-01-01

    Bacterial attachment and biofilm formation can lead to poor hygienic conditions in food processing environments. Furthermore, interactions between different bacteria may induce or promote biofilm formation. In this study, we isolated and identified a total of 687 bacterial strains from seven......-culture biofilm production with high relevance for food safety and food production facilities....

  5. Sulfate reducing bacteria and their activities in oil sands process-affected water biofilm.

    Liu, Hong; Yu, Tong; Liu, Yang

    2015-12-01

    Biofilm reactors were constructed to grow stratified multispecies biofilm in oil sands process-affected water (OSPW) supplemented with growth medium. The development of sulfate reducing bacteria (SRB) within the biofilm and the biofilm treatment of OSPW were evaluated. The community structure and potential activity of SRB in the biofilm were investigated with H2S microsensor measurements, dsrB gene-based denaturing gradient gel electrophoresis (DGGE), and the real time quantitative polymerase chain reaction (qPCR). Multispecies biofilm with a thickness of 1000 μm was successfully developed on engineered biocarriers. H2S production was observed in the deeper anoxic zone of the biofilm from around 750 μm to 1000 μm below the bulk water-biofilm interface, revealing sulfate reduction in the deeper zone of the stratified biofilm. The biofilm removed chemical oxygen demand (COD), sulfate, and nitrogen. The study expands current knowledge of biofilm treatment of OSPW and the function of anaerobic SRB in OSPW biofilm, and thus provides information for future bioreactor development in the reclamation of OSPW. PMID:26204047

  6. Decreasing ammonium generation using hydrogenotrophic bacteria in the process of nitrate reduction by nanoscale zero-valent iron

    An integrated nitrate treatment using nanoscale zero-valent iron (NZVI) and Alcaligenes eutrophus, which is a kind of hydrogenotrophic denitrifying bacteria, was conducted to remove nitrate and decrease ammonium generation. Within 8 days, nitrate was removed completely in the reactors containing NZVI particles plus bacteria while the proportion of ammonium generated was only 33%. That is a lower reduction rate but a smaller proportion of ammonium relative to that in abiotic reactors. It was also found that ammonium generation experienced a biphasic process, involving an increasing period and a stable period. After domestication of the bacteria, the combined NZVI-cell system could remove all nitrate without ammonium released when the refreshed nitrate was introduced. Nitrate reduction and the final product distribution were also studied in batch reactors amended with different initial NZVI contents and biomass concentrations, respectively. Both the nitrate removal rate and the ammonium yield decreased when the initial content of NZVI reduced and the initial biomass concentration increased. However, about 27% of the nitrate was converted to ammonium when excess bacteria (OD422 = 0.026) were used, which was higher than that with appropriate amount of bacteria.

  7. Decreasing ammonium generation using hydrogenotrophic bacteria in the process of nitrate reduction by nanoscale zero-valent iron

    An, Yi; Li, Tielong [College of Environmental Science and Engineering/Tianjin Key Laboratory of Environmental Remediation and Pollution Control/Ministry of Education Key Laboratory of Pollution Processed and Environmental Criteria, Nankai University, Tianjin 300071 (China); Jin, Zhaohui, E-mail: jinzh@nankai.edu.cn [College of Environmental Science and Engineering/Tianjin Key Laboratory of Environmental Remediation and Pollution Control/Ministry of Education Key Laboratory of Pollution Processed and Environmental Criteria, Nankai University, Tianjin 300071 (China); Dong, Meiying; Li, Qianqian; Wang, Shuaima [College of Environmental Science and Engineering/Tianjin Key Laboratory of Environmental Remediation and Pollution Control/Ministry of Education Key Laboratory of Pollution Processed and Environmental Criteria, Nankai University, Tianjin 300071 (China)

    2009-10-15

    An integrated nitrate treatment using nanoscale zero-valent iron (NZVI) and Alcaligenes eutrophus, which is a kind of hydrogenotrophic denitrifying bacteria, was conducted to remove nitrate and decrease ammonium generation. Within 8 days, nitrate was removed completely in the reactors containing NZVI particles plus bacteria while the proportion of ammonium generated was only 33%. That is a lower reduction rate but a smaller proportion of ammonium relative to that in abiotic reactors. It was also found that ammonium generation experienced a biphasic process, involving an increasing period and a stable period. After domestication of the bacteria, the combined NZVI-cell system could remove all nitrate without ammonium released when the refreshed nitrate was introduced. Nitrate reduction and the final product distribution were also studied in batch reactors amended with different initial NZVI contents and biomass concentrations, respectively. Both the nitrate removal rate and the ammonium yield decreased when the initial content of NZVI reduced and the initial biomass concentration increased. However, about 27% of the nitrate was converted to ammonium when excess bacteria (OD{sub 422} = 0.026) were used, which was higher than that with appropriate amount of bacteria.

  8. The taxonomic and physiologic diversity of the acidophilic bacteria of the genus Thiobacillus used in ores solubilization processes

    Carmen Mădălina Cişmaşiu

    2010-01-01

    Full Text Available The development of biotechnological processes, based mainly on the activity of the acidophilic chemolithotrophic, proved their efficiency in recovering metals from sulphides ores and mining drains and in bioremediation of the polluted environment with residual inorganic substances, like the heavy metals ions and their compounds.Due to the influence of the physical-chemical factors on the development and the metabolic activity of the microorganism’s present in the industrial effluents, the study of these parameters was imposed for raising the efficiency of the processes of adsorption and biosolubilization of the metallic ions. A special importance for using bacteria of the genus Acidithiobacillus in the biosolubilization processes of heavy metals from acid mine tailings is represented by the resistance of these bacteria to high concentrations of metal ions.The experiments prove a strong relationship between the acidity of the medium and the behaviour of the acidophilic chemolithotrophic bacteria. The comparative analyses regarding the influence of metallic ions (Cu2+, Zn2+ and Fe2+ on the physiologic diversity of the Acidithiobacillus populations, isolated from the mining sites, demonstrated the higher resistance of these bacteria to higher concentrations of metallic ions.

  9. Investigate the feasibility of using image processing method for the count of bacteria and comparison with Colony Counter

    Mohammad javad Akbarian Mymand; samane farji kafshgari; alireza sadeghi mahounak; seyyed abdollah hoseyni sharghi; mehdi vatan khah

    2014-01-01

    Background and Aim: Considering the importance of quality and bacterial contamination in food products, a rapid, accurate and able method to deliver consistent results for counting bacteria is an essential. Application of image processing in the measurement of quality is one of important research topics. This method is very accurate and non-destructive with constant results. The aim of this study was the use of image processing in bacterial count (Quail flora, sourdough and drinks kefir) and ...

  10. Role of protein phosphorylation in the regulation of cell cycle and DNA-related processes in bacteria

    Transito eGarcia-Garcia

    2016-02-01

    Full Text Available In all living organisms, the phosphorylation of proteins modulates various aspects of their functionalities. In eukaryotes, protein phosphorylation plays a key role in cell signaling, gene expression, and differentiation. Protein phosphorylation is also involved in the global control of DNA replication during the cell cycle, as well as in the mechanisms that cope with stress-induced replication blocks. Similar to eukaryotes, bacteria use Hanks-type kinases and phosphatases for signal transduction, and protein phosphorylation is involved in numerous cellular processes. However, it remains unclear whether protein phosphorylation in bacteria can also regulate the activity of proteins involved in DNA-mediated processes such as DNA replication or repair. Accumulating evidence supported by functional and biochemical studies suggests that phospho-regulatory mechanisms also take place during the bacterial cell cycle. Recent phosphoproteomics and interactomics studies identified numerous phosphoproteins involved in various aspect of DNA metabolism strongly supporting the existence of such level of regulation in bacteria. Similar to eukaryotes, bacterial scaffolding-like proteins emerged as platforms for kinase activation and signaling. This review reports the current knowledge on the phosphorylation of proteins involved in the maintenance of genome integrity and the regulation of cell cycle in bacteria that reveals surprising similarities to eukaryotes.

  11. [Community Characteristics of ANAMMOX Bacteria in Subsurface Flow Constructed Wetland (SSFCW) for Processing of Aquaculture Waster Water].

    Zeng, Xian-lei; Liu, Xing-guo; Wu, Zong-fan; Shi, Xu; Lu, Shi-min

    2016-02-15

    Anaerobic ammonium oxidation (ANAMMOX) is one of the important functions in waste water treatment by subsurface flow constructed wetland (SSFCW), however, there are few studies on ANAMMOX in SSFCW environment at present. The community characteristics of ANAMMOX in the SSFCW of processing aquaculture waste water were explored in this study. In order to analyze the structure, diversity and abundance of ANAMMOX bacteria, several 16S rRNA clone libraries were constructed and real-time PCR targeting specific 16S rRNA genes together with diversity analysis was adopted. The obtained results showed that the SSFCW identified a total of three unknown clusters and two known clusters including Candidatus brocadia and Candidatus kuenenia. The dominant cluster was Candidatus brocadia. The highest diversity levels of ANAMMOX bacteria occurred in autumn (H', 1.21), while the lowest in spring (H', 0.64). The abundance of ANAMMOX bacteria in SSFCW environment ranged from 8.0 x 10(4) to 9.4 x 10(6) copies x g(-1) of fresh weight and the copy number of total bacterial 16S rRNA genes ranged from 7.3 x 10(9) to 9.1 x 10(10) copies x g(-1) of fresh weight during culture cycle. There were significant differences in the ANAMMOX bacteria abundances of different stratum and seasons in SSFCW environment, but the differences in total bacterial abundances were not obvious. In addition, the differences in ANAMMOX bacteria abundances in different stratum and seasons in SSFCW environment were irregular in different culture cycle. According to the distribution characteristics of ANAMMOX bacteria in the wetland, the denitrification effect of SSFCW could be improved by changing the supplying manners of aquaculture wastewater and adjusting the structure of wetland. The research results will provide reference for further optimizing the SSFCW and improving the efficiency of purification. PMID:27363152

  12. Isolation of biofilm-forming bacteria from a fresh-cut processing plant and co-culturing with E. coli O157:H7

    In produce processing plants, biofilms can theoretically provide a supporting environment for pathogenic bacteria that is resistant to cleaning and sanitizing efforts. The objective of this study was to recover bacteria from a commercial produce processing plant that have the ability to form biofilm...

  13. Development of microfluidic device for cell counting and lysis

    Václavek, Tomáš; Křenková, Jana; Foret, František

    Veszprém : Hungarian Society for Separation Sciences, 2015. s. 140-140. ISBN 978-615-5270-18-5. [Balaton Symposium on High-Performance Separation Methods /10./. 02.09.2015-04.09.2015, Siófok] R&D Projects: GA ČR(CZ) GA14-06319S; GA ČR(CZ) GBP206/12/G014 Institutional support: RVO:68081715 Keywords : microfluidic device * cell counting * cell lysis Subject RIV: CB - Analytical Chemistry, Separation

  14. Enzymatic lysis of the pseudomurein-containing methanogen Methanobacterium formicicum.

    Bush, J W

    1985-01-01

    A streptomycete isolated from cow manure produces an extracellular enzyme capable of lysing the pseudomurein-containing methanogen Methanobacterium formicicum. The lytic activity has been partially purified from culture fluid and appears to be a serine protease. Similar lytic activity has been fractionated from pronase. Optimal conditions have been developed for lysis of M. formicicum by commercial preparations of proteinase K. The three lytic enzymes have been partially characterized. The re...

  15. The Presence of Mercury Resistant Bacteria in Sediment of Gold Processing Plant at Waekerta Village of Buru District, Maluku Province and their Activity in Reducing Mercury

    Sarmawaty Kotala

    2014-08-01

    Full Text Available Mercury was one of the heavy metal polute in environment and had the toxic characteristic to the living creatures. Golden mining in Waeapo subdistrict used mercury to extract the gold and exile the waste to the environment freely. Several precedented research showed that waste sediment of gold processing contains mercury resistance bacteria. Mercury resistance bacteria can be used as bioremediation agent because those bacteria can reduce mercury. Mercury resistance bacteria has mer operon which contained in plasmid. The goal of this research is to isolate mercury resistance bacteria which is able to grow on medium nutrient agar (NA containing 500 ppm of HgCl2 and to analyze the capability in HgCl2 reduction in nutrient broth (NB medium. Bacteria isolation was done by platting method on Nutrient Agar containing 10 ppm of HgCl2. Bacteria identification was done by kit Microgen TM GnA + B-ID System and to know bacteria capability in reducing mercury was done by CV-AAS (Cold Vapour Atomic Absorption Spectrophotometer. Result showed, that the bacteria found in this research were Bacillus sp and Aeromonas hydrophila. Both of these bacteria were able to reduce HgCl2 in the amount of 98,7% for Bacillus sp and 98,33% for Aeromonas hydrophila. In the future those bacteria can be use as bioremediation agent.

  16. Fibrin clot formation and lysis: basic mechanisms

    Sidelmann, JJ; Gram, J; Jespersen, J;

    2000-01-01

    The hemostatic balance, introduced more than 40 years ago, addresses the components and reactions involved in fibrin turnover. Fibrin is placed in the core of this delicate balance. Defects in the mechanisms responsible for fibrin turnover might lead to thrombosis or bleeding, and fibrin...... consequently is an important substrate in the physiology of hemostasis. This review describes the components and processes involved in fibrin formation and fibrin degradation. Particular emphasis is put on the reactions involved in the conversion of fibrinogen to fibrin, the polymerization of fibrin molecules...... induced by coagulation factor XIII (FXIII), and the degradation of fibrinogen and fibrin mediated by plasmin and elastase. Furthermore, factors influencing fibrin structure and fibrin breakdown are addressed; in particular polymorphisms in the genes coding for fibrinogen and FXIII, but also the physical...

  17. Bacteriophage cell lysis of Shiga toxin-producing Escherichia coli for top-down proteomic identification of Shiga toxin 1 & 2 using matrix-assisted laser desorption/ionization tandem time-of-light mass spectrometry

    RATIONALE: Analysis of bacteria by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) often relies upon sample preparation methods that result in cell lysis, e.g. bead-beating. However, Shiga toxin-producing Escherichia coli (STEC) can undergo bacteriophage...

  18. Information processing in bacteria: memory, computation, and statistical physics: a key issues review

    Lan, Ganhui; Tu, Yuhai

    2016-05-01

    preserving information, it does not reveal the underlying mechanism that leads to the observed input-output relationship, nor does it tell us much about which information is important for the organism and how biological systems use information to carry out specific functions. To do that, we need to develop models of the biological machineries, e.g. biochemical networks and neural networks, to understand the dynamics of biological information processes. This is a much more difficult task. It requires deep knowledge of the underlying biological network—the main players (nodes) and their interactions (links)—in sufficient detail to build a model with predictive power, as well as quantitative input-output measurements of the system under different perturbations (both genetic variations and different external conditions) to test the model predictions to guide further development of the model. Due to the recent growth of biological knowledge thanks in part to high throughput methods (sequencing, gene expression microarray, etc) and development of quantitative in vivo techniques such as various florescence technology, these requirements are starting to be realized in different biological systems. The possible close interaction between quantitative experimentation and theoretical modeling has made systems biology an attractive field for physicists interested in quantitative biology. In this review, we describe some of the recent work in developing a quantitative predictive model of bacterial chemotaxis, which can be considered as the hydrogen atom of systems biology. Using statistical physics approaches, such as the Ising model and Langevin equation, we study how bacteria, such as E. coli, sense and amplify external signals, how they keep a working memory of the stimuli, and how they use these data to compute the chemical gradient. In particular, we will describe how E. coli cells avoid cross-talk in a heterogeneous receptor cluster to keep a ligand-specific memory. We will also

  19. Information processing in bacteria: memory, computation, and statistical physics: a key issues review

    Lan, Ganhui; Tu, Yuhai

    2016-05-01

    preserving information, it does not reveal the underlying mechanism that leads to the observed input-output relationship, nor does it tell us much about which information is important for the organism and how biological systems use information to carry out specific functions. To do that, we need to develop models of the biological machineries, e.g. biochemical networks and neural networks, to understand the dynamics of biological information processes. This is a much more difficult task. It requires deep knowledge of the underlying biological network—the main players (nodes) and their interactions (links)—in sufficient detail to build a model with predictive power, as well as quantitative input-output measurements of the system under different perturbations (both genetic variations and different external conditions) to test the model predictions to guide further development of the model. Due to the recent growth of biological knowledge thanks in part to high throughput methods (sequencing, gene expression microarray, etc) and development of quantitative in vivo techniques such as various florescence technology, these requirements are starting to be realized in different biological systems. The possible close interaction between quantitative experimentation and theoretical modeling has made systems biology an attractive field for physicists interested in quantitative biology. In this review, we describe some of the recent work in developing a quantitative predictive model of bacterial chemotaxis, which can be considered as the hydrogen atom of systems biology. Using statistical physics approaches, such as the Ising model and Langevin equation, we study how bacteria, such as E. coli, sense and amplify external signals, how they keep a working memory of the stimuli, and how they use these data to compute the chemical gradient. In particular, we will describe how E. coli cells avoid cross-talk in a heterogeneous receptor cluster to keep a ligand-specific memory. We will also

  20. Information processing in bacteria: memory, computation, and statistical physics: a key issues review.

    Lan, Ganhui; Tu, Yuhai

    2016-05-01

    preserving information, it does not reveal the underlying mechanism that leads to the observed input-output relationship, nor does it tell us much about which information is important for the organism and how biological systems use information to carry out specific functions. To do that, we need to develop models of the biological machineries, e.g. biochemical networks and neural networks, to understand the dynamics of biological information processes. This is a much more difficult task. It requires deep knowledge of the underlying biological network-the main players (nodes) and their interactions (links)-in sufficient detail to build a model with predictive power, as well as quantitative input-output measurements of the system under different perturbations (both genetic variations and different external conditions) to test the model predictions to guide further development of the model. Due to the recent growth of biological knowledge thanks in part to high throughput methods (sequencing, gene expression microarray, etc) and development of quantitative in vivo techniques such as various florescence technology, these requirements are starting to be realized in different biological systems. The possible close interaction between quantitative experimentation and theoretical modeling has made systems biology an attractive field for physicists interested in quantitative biology. In this review, we describe some of the recent work in developing a quantitative predictive model of bacterial chemotaxis, which can be considered as the hydrogen atom of systems biology. Using statistical physics approaches, such as the Ising model and Langevin equation, we study how bacteria, such as E. coli, sense and amplify external signals, how they keep a working memory of the stimuli, and how they use these data to compute the chemical gradient. In particular, we will describe how E. coli cells avoid cross-talk in a heterogeneous receptor cluster to keep a ligand-specific memory. We will also

  1. Volatile Organic Compounds Produced by Bacteria from the Poultry Processing Environment

    In recent years the characterization of volatile organic compounds (VOCs) emitted from food-borne bacteria has prompted studies on the development of approaches to utilize the profile of volatiles emitted as a way of detecting contamination. We have examined VOCs from poultry with this in mind. Patt...

  2. Development and applications of a DNA labeling method with magnetic nanoparticles to study the role of horizontal gene transfer events between bacteria in soil pollutant bioremediation processes.

    Pivetal, J; Frénéa-Robin, M; Haddour, N; Vézy, C; Zanini, L F; Ciuta, G; Dempsey, N M; Dumas-Bouchiat, F; Reyne, G; Bégin-Colin, S; Felder-Flesh, D; Ghobril, C; Pourroy, G; Simonet, P

    2015-12-01

    Horizontal gene transfers are critical mechanisms of bacterial evolution and adaptation that are involved to a significant level in the degradation of toxic molecules such as xenobiotic pesticides. However, understanding how these mechanisms are regulated in situ and how they could be used by man to increase the degradation potential of soil microbes is compromised by conceptual and technical limitations. This includes the physical and chemical complexity and heterogeneity in such environments leading to an extreme bacterial taxonomical diversity and a strong redundancy of genes and functions. In addition, more than 99 % of soil bacteria fail to develop colonies in vitro, and even new DNA-based investigation methods (metagenomics) are not specific and sensitive enough to consider lysis recalcitrant bacteria and those belonging to the rare biosphere. The objective of the ANR funded project “Emergent” was to develop a new culture independent approach to monitor gene transfer among soil bacteria by labeling plasmid DNA with magnetic nanoparticles in order to specifically capture and isolate recombinant cells using magnetic microfluidic devices. We showed the feasibility of the approach by using electrotransformation to transform a suspension of Escherichia coli cells with biotin-functionalized plasmid DNA molecules linked to streptavidin-coated superparamagnetic nanoparticles. Our results have demonstrated that magnetically labeled cells could be specifically retained on micromagnets integrated in a microfluidic channel and that an efficient selective separation can be achieved with the microfluidic device. Altogether, the project offers a promising alternative to traditional culture-based approaches for deciphering the extent of horizontal gene transfer events mediated by electro or natural genetic transformation mechanisms in complex environments such as soil. PMID:26498963

  3. Metagenomics as a tool to obtain full genomes of process-critical bacteria in engineered systems

    Albertsen, Mads; Hugenholtz, Philip; Tyson, Gene W.;

    parameters with functions of specific bacteria within the ecosystems in order to decipher principles that might be used to control and predict ecosystem performance. The main bottleneck in obtaining genomes from the environment is that the vast majority of bacteria are not readily cultured. Metagenomics......, the sequencing of bulk genomic DNA from environmental samples, has the potential to provide genomes of this uncultured majority. However, so far only few bacterial genomes have been obtained from metagenomic data. In this study we present a new approach to obtain individual genomes from metagenomes. We deeply...... sequenced two metagenomes from the same environmental sample, but using two independent DNA extraction methods, which resulted in different population abundances. This allowed sequence-composition independent binning of numerous high quality draft genomes from both high and low abundant members...

  4. Self-bioremediation of cork-processing wastewaters by (chloro)phenol-degrading bacteria immobilised onto residual cork particles.

    del Castillo, I; Hernández, P; Lafuente, A; Rodríguez-Llorente, I D; Caviedes, M A; Pajuelo, E

    2012-04-15

    Cork manufacturing is a traditional industry in Southern Europe, being the main application of this natural product in wine stoppers and insulation. Cork processing begins at boiling the raw material. As a consequence, great volumes of dark wastewaters, with elevated concentrations of chlorophenols, are generated, which must be depurated through costly physicochemical procedures before discarding them into public water courses. This work explores the potential of bacteria, isolated from cork-boiling waters storage ponds, in bioremediation of the same effluent. The bacterial population present in cork-processing wastewaters was analysed by DGGE; low bacterial biodiversity was found. Aerobic bacteria were isolated and investigated for their tolerance against phenol and two chlorophenols. The most tolerant strains were identified by sequencing 16S rDNA. The phenol-degrading capacity was investigated by determining enzyme activities of the phenol-degrading pathway. Moreover, the capacity to form biofilms was analysed in a microtitre plate assay. Finally, the capacity to form biofilms onto the surface of residual small cork particles was evaluated by acridine staining followed by epifluorescence microscopy and by SEM. A low-cost bioremediation system, using phenol-degrading bacteria immobilised onto residual cork particles (a by-product of the industry) is proposed for the remediation of this industrial effluent (self-bioremediation). PMID:22265252

  5. Differentiation in the microbial ecology and activity of suspended and attached bacteria in a nitritation-anammox process.

    Park, Hongkeun; Sundar, Suneethi; Ma, Yiwei; Chandran, Kartik

    2015-02-01

    A directed differentiation between the biofilm and suspension was observed in the molecular microbial ecology and gene expression of different bacteria in a biofilm nitritation-anammox process operated at varying hydraulic residence times (HRT) and nitrogen loading rates (NLR). The highest degree of enrichment observed in the biofilm was of anaerobic ammonia-oxidizing bacteria (AMX) followed by that of Nitrospira spp. related nitrite-oxidizing bacteria (NOB). For AMX, a major shift from Candidatus "Brocadia fulgida" to Candidatus "Kuenenia stuttgartiensis" in both suspension and biofilm was observed with progressively shorter HRT, using discriminatory biomarkers targeting the hydrazine synthase (hzsA) gene. In parallel, expression of the hydrazine oxidoreductase gene (hzo), a functional biomarker for AMX energy metabolism, became progressively prominent in the biofilm. A marginal but statistically significant enrichment in the biofilm was observed for Nitrosomonas europaea related ammonia-oxidizing bacteria (AOB). In direct contrast to AMX, the gene expression of ammonia monooxygenase subunit A (amoA), a functional biomarker for AOB energy metabolism, progressively increased in suspension. Using gene expression and biomass concentration measures in conjunction, it was determined that signatures of AOB metabolism were primarily present in the biofilm throughout the study. On the other hand, AMX metabolism gradually shifted from being uniformly distributed in both the biofilm and suspension to primarily the biofilm at shorter HRTs and higher NLRs. These results therefore highlight the complexity and key differences in the microbial ecology, gene expression and activity between the biofilm and suspension of a nitritation-anammox process and the biokinetic and metabolic drivers for such niche segregation. PMID:25115980

  6. Operation of three parallel AN/AO processes to enrich denitrifying phosphorus removing bacteria for low strength wastewater treatment

    XIA Si-qing; LIU Hong-bo

    2006-01-01

    Three parallel anaerobic-anoxic/anaerobic-aerobic (AN/AO) processes were developed to enrich denitrifying phosphorus removal bacteria (DPB) for low strength wastewater treatment. The main body of the parallel AN/AO process consists of an AN(anaerobic-anoxic) process and an AO (anaerobic-aerobic) process. In the AO process, the common phosphorus accumulating organisms (PAOs) was dominate, while in the AN process, DPB was dominate. The volume of anaerobic zone(Vana):anoxic zone(Vano):aerobic zone (Vaer) for the parallel AN/AO process is 1:1:1 in contrast with a Vana:Vaer and Vano,:Vaer of 1:2 and 1:4 for a traditional biological nutrient removal process (BNR). Process 3 excels in the 3 processes on the basis of COD, TN and TP removal. For 4 month operation, the effluent COD concentration of process 3 did not exceed 60 mg/L; the effluent TN concentration of process 3 was lower than 15 mg/L; and the effluent TP concentration of process 3 was lower than 1 mg/L.

  7. Rapid, Effective DNA Isolation from Osmanthus via Modified Alkaline Lysis.

    Alexander, Lisa

    2016-07-01

    Variability of leaf structure and presence of secondary metabolites in mature leaf tissue present a challenge for reliable DNA extraction from Osmanthus species and cultivars. The objective of this study was to develop a universal rapid, effective, and cost-efficient method of DNA isolation for Osmanthus mature leaf tissue. Four different methods were used to isolate DNA from 8 cultivars of Osmanthus. Absorbance spectra, DNA concentration, appearance on agarose gel, and performance in PCR were used to analyze quality, quantity, and integrity of isolated DNA. Methods were ranked in order, based on total quantity, quality, and performance points as the following: 1) solid-phase extraction (SPE), 2) modified alkaline lysis (SDS), 3) cetyltrimethylammonium bromide (CTAB) with chloroform (CHL), and 4) CTAB with phenol/chloroform (PHE). Total DNA, isolated via SPE, showed the least contamination but the lowest mean quantity (9.6 ± 3.4 μg) and highest cost. The highest quantity of DNA was isolated via SDS (117 ± 54.1 μg). SPE and SDS resolved the most individuals on agarose gel, whereas the 2 CTAB methods had poorly resolved gels. All methods except PHE performed well in PCR. Additions to the modified alkaline lysis method increased A260:A230 by up to 59% without affecting yield. With the use of SDS, an average of 1000 μg/g DNA was isolated from fresh leaf tissue of 18 samples in ∼1.5 h at a cost of 0.74 U.S. dollars (USD)/sample. We recommend improved alkaline lysis as a rapid, effective, and cost-efficient method of isolating DNA from Osmanthus species. PMID:26816495

  8. Vertical distribution of bacteria and intensity of microbiological processes in two stratified gypsum Karst Lakes in Lithuania

    Krevs A.

    2011-08-01

    Full Text Available Physical-chemical parameters and the vertical distribution of bacteria and organic matter production-destruction processes were studied during midsummer stratification in two karst lakes (Kirkilai and Ramunelis located in northern Lithuania. The lakes were characterized by high sulfate concentrations (369–1248 mg·L-1. The O2/H2S intersection zone formed at 2–3 m depth. In Lake Kirkilai, the highest bacterial densities (up to 8.7 × 106 cell·mL-1 occurred at the O2/H2S intersection zone, whereas in Lake Ramunelis the highest densities were observed in the anoxic hypolimnion (up to 11 × 106 cell·mL-1. Pigment analysis revealed that green sulfur bacteria dominated in the microaerobic–anaerobic water layers in both lakes. The most intensive development of sulfate-reducing bacteria was observed in the anaerobic layer. Photosynthetic production of organic matter was highest in the upper layer. Rates of sulfate reduction reached 0.23 mg S2−·dm3·d-1 in the microaerobic-anaerobic water layer and 1.97 mg S2−·dm3·d-1 in sediments. Karst lakes are very sensitive to organic pollution, because under such impact in the presence of high sulfate amounts, sulfate reduction may become very intensive and, consequently, the increase in hydrogen sulfide and development of sulfur cycle bacteria may reduce the variety of other hydrobionts.

  9. Synechococcus growth in the ocean may depend on the lysis of heterotrophic bacteria

    Weinbauer, M.G.; Bonilla-Findji, O.; Chan, A.M.; Dolan, J. R.; Short, S.M.; Šimek, Karel; Wilhelm, S. W.; Suttle, C.A.

    2011-01-01

    Roč. 33, č. 10 (2011), s. 1465-1476. ISSN 0142-7873 R&D Projects: GA ČR(CZ) GA206/08/0015 Institutional research plan: CEZ:AV0Z60170517 Keywords : viruses * growth control of cyanobacteria * heterotrophic bacterioplankton Subject RIV: EE - Microbiology, Virology Impact factor: 2.079, year: 2011

  10. Large-scale clinical comparison of the lysis-centrifugation and radiometric systems for blood culture

    The Isolator 10 lysis-centrifugation blood culture system (E. I. du Pont de Nemours and Co., Inc., Wilmington, Del.) was compared with the BACTEC radiometric method (Johnston Laboratories, Inc., Towson, Md.) with 6B and 7D broth media for the recovery of bacteria and yeasts. From 11,000 blood cultures, 1,174 clinically significant organisms were isolated. The Isolator system recovered significantly more total organisms, members of the family Enterobacteriaceae, Staphylococcus spp., and yeasts. The BACTEC system recovered significantly more Pseudomonas spp., Streptococcus spp., and anaerobes. Of the Isolator colony counts, 87% measured less than 11 CFU/ml of blood. Organisms, on an average, were detected the same day from each of the two culture systems. Only 13 of the 975 BACTEC isolates (0.01%) were recovered by subculture of growth-index-negative bottles, and 12 of the 13 were detected in another broth blood culture taken within 24 h. Contaminants were recovered from 4.8% of the Isolator 10 and 2.3% of the BACTEC cultures

  11. On-chip lysis of mammalian cells through a handheld corona device.

    Escobedo, C; Bürgel, S C; Kemmerling, S; Sauter, N; Braun, T; Hierlemann, A

    2015-07-21

    On-chip lysis is required in many lab-on-chip applications involving cell studies. In these applications, the complete disruption of the cellular membrane and a high lysis yield is essential. Here, we present a novel approach to lyse cells on-chip through the application of electric discharges from a corona handheld device. The method only requires a microfluidic chip and a low-cost corona device. We demonstrate the effective lysis of BHK and eGFP HCT 116 cells in the sub-second time range using an embedded microelectrode. We also show cell lysis of non-adherent K562 leukemia cells without the use of an electrode in the chip. Cell lysis has been assessed through the use of bright-field microscopy, high-speed imaging and cell-viability fluorescence probes. The experimental results show effective cell lysis without any bubble formation or significant heating. Due to the simplicity of both the components involved and the lysis procedure, this technique offers an inexpensive lysis option with the potential for integration into lab-on-a-chip devices. PMID:26055165

  12. Biological variation in tPA-induced plasma clot lysis time

    S. Talens (Simone); J.J.M.C. Malfliet (Joyce); G. Rudež (Goran); H.M.H. Spronk (Henri); N.A.H. Janssen (N. A H); P. Meijer (Piet); C. Kluft (Cornelius); M.P.M. de Maat (Moniek); D.C. Rijken (Dingeman)

    2012-01-01

    textabstractHypofibrinolysis is a risk factor for venous and arterial thrombosis, and can be assessed by using a turbidimetric tPA-induced clot lysis time (CLT) assay. Biological variation in clot lysis time may affect the interpretation and usefulness of CLT as a risk factor for thrombosis. Suffici

  13. [Physiological and biochemical activity of bacteria during germination of cucumber seeds and impact of ciliates Colpoda steinii on this process].

    Chobotarova, V V; Bega, Z T; Kurdish, I K

    2015-01-01

    It is shown that the bacteria Bacillus subtilis B-7023 IMV produce indole-3-acetic acid and amino acids in the liquid medium Knoop. Processing cucumber seed suspension containing 10(7) cfu/ml as bacilli, and Azotobacter vinelandii IMV V-7076, resulted in a decrease in the length of the roots of plants. Reduction of bacterial load bacilli to 10(6) cfu/ml followed by reduction of indole-3-acetic acid in the medium, and to an increase in the length of roots, shoots and total plant mass. During the cultivation of Bacillus subtilis IMV V-7023 with ciliates Colpoda steinii reduced the amount of free forms of auxin in the medium to 5.5 times, and the related--to trace amounts. The content of histidine, phenylalanine, tyrosine, methionine and lysine significantly reduced. PMID:26036028

  14. APPLICATION OF RESPIROMETRIC TESTS FOR ASSESSMENT OF METHANOGENIC BACTERIA ACTIVITY IN WASTEWATER SLUDGE PROCESSING

    Małgorzata Cimochowicz-Rybicka

    2013-07-01

    Full Text Available Production of a methane-rich gas (‘biogas’ is contemporary popular sludges processing technology which allows to generate thermal and/or electric energy. Formal requirements issued by the European Union to promote so called renewable energy resources made these process more attractive leading to its application in WWTPs which were designed based on different sludge handling processes. Authors (as active design engineers noted that dimensioning sludge digestion chamber is usually based on SRT assessment without any emphasis on sludge characteristics. Bio-mass characteristics and the estimation of its activity with respect to methane production are of great importance, from both scientific and practical points of view, as anaerobic digestion appears to be one of crucial processes in municipal wastewater handling and disposal. The authors propose respirometric tests to estimate a biomass potential to produce ‘a biogas’ and several years’ laboratory and full scale experience proved its usefulness and reliability both as a measurement and a design tool applicable in sludge handling. Dimensioning method proposed by authors, allows to construct and optimize operation of digestion chambers based on a methanogenic activity.

  15. Allergenicity in food allergy : influence of food processing and immunomodulation by lactic acid bacteria

    Vissers, Y.M.

    2011-01-01

    Allergic diseases such as allergic rhinitis, allergic asthma, atopic eczema and food allergy have become an increasing health problem world-wide, affecting between 20-30% of the total population. Peanut allergy (prevalence ~1%) is a common and persistent food allergy accounting for severe allergic reactions. Peanuts are often consumed after thermal processing (e.g. boiling, roasting) which can alter the protein structure and change its immunoreactivity and allergenicity. In vitro diagnostic ...

  16. Sunlight inactivation of fecal indicator bacteria in open-water unit process wetlands

    Nguyen, Mi T.

    2015-01-01

    Constructed wetlands harness natural processes to provide a low cost and energy technology for wastewater treatment. Although not the primary goal of wetland design, wetlands may remove and inactivate pathogens via a number of mechanisms including sunlight inactivation, predation, and sorption coupled to sedimentation. The contribution of sunlight inactivation is generally insignificant in vegetated wetlands due to light screening by emergent macrophytes and deep water. A novel wetland design...

  17. The Importance of Endospore-Forming Bacteria Originating from Soil for Contamination of Industrial Food Processing

    Specific endo spore formers have become important contaminants in industrial food processing. The direct or indirect soil route of contamination or dispersal is the start of events or processes in the agrofood chain that eventually leads to important problems or concerns for food safety and/or quality. Three important food sectors are discussed in this paper. In the dairy sector, Bacillus cereus, the most important pathogen or spoilage organism in this sector, and Clostridium tyrobutyricum, the most important spoiler in certain cheeses, both contaminate pasteurized milk through the faecal and/or (at least for B. cereus) the direct soil route. In the fruit juice industry, Alicyclobacillus acidoterrestris, present on raw fruits, has become a major quality-target organism. In the ready-to-eat food sector, B. cereus and other aerobic endo spore formers are introduced via vegetables, fruits, or herbs and spices, while anaerobic spore formers like non proteolytic Clostridium botulinum and Clostridium estertheticum pose safety and spoilage risks in chilled packaged foods, respectively

  18. Making soy sauce from defatted soybean meal without the mejus process by submerged cultivation using thermophilic bacteria.

    Hur, Jeong Min; Park, Doo Hyun

    2015-08-01

    The diversity of thermophilic bacteria was not significantly altered while growing in a defatted soybean meal (DFSM) slurry at 60 °C for 10, 20, and 30 days. Five species of thermophilic bacteria, which belong to the genera Aeribacillus (temperature gradient gel electrophoresis [TGGE] band no. 1), Saccharococcus (TGGE band no. 2), Geobacillus (TGGE band no. 3), Bacillus (TGGE band no. 4), and Anoxybacillus (TGGE band no. 5), were detected in the fermenting DFSM slurry. The cell-free culture fluid obtained from the fermenting DFSM slurry on day 14 hydrolyzed starch and soy protein at 60 °C but not at 30 °C. Soy sauce (test soy sauce) was prepared from the fermented DFSM slurry after a 30 day cultivation at 60 °C and a 60 day ripening at 45 °C. Free amino acid (AA) and organic acid contents in the soy sauce increased in proportion to the fermentation period, whereas ammonium decreased proportionally. Mg and Ca contained in the soy sauce decreased proportionally during fermentation and were lower than those in the non-fermented DFSM extract (control). Spectral absorbance of soy sauce prepared from the fermented DFSM slurry was maximal at 430 nm and increased slightly in proportion to the fermentation period. The aroma and flavor of the test soy sauce were significantly different from those of traditional Korean soy sauce. Conclusively, soy sauce may be prepared directly from the fermented DFSM slurry without meju-preparing process and fermentation period may be a factor for control of soy sauce quality. PMID:26243923

  19. Single molecule resolution of the antimicrobial action of quantum dot-labeled sushi peptide on live bacteria

    Chen Jianzhu

    2009-05-01

    Full Text Available Abstract Background Antimicrobial peptides are found in all kingdoms of life. During the evolution of multicellular organisms, antimicrobial peptides were established as key elements of innate immunity. Most antimicrobial peptides are thought to work by disrupting the integrity of cell membranes, causing pathogen death. As antimicrobial peptides target the membrane structure, pathogens can only acquire resistance by a fundamental change in membrane composition. Hence, the evolution of pathogen resistance has been a slow process. Therefore antimicrobial peptides are valuable alternatives to classical antibiotics against which multiple drug-resistant bacteria have emerged. For potential therapeutic applications as antibiotics a thorough knowledge of their mechanism of action is essential. Despite the increasingly comprehensive understanding of the biochemical properties of these peptides, the actual mechanism by which antimicrobial peptides lyse microbes is controversial. Results Here we investigate how Sushi 1, an antimicrobial peptide derived from the horseshoe crab (Carcinoscorpius rotundicauda, induces lysis of Gram-negative bacteria. To follow the entire process of antimicrobial action, we performed a variety of experiments including transmission electron microscopy and fluorescence correlation spectroscopy as well as single molecule tracking of quantum dot-labeled antimicrobial peptides on live bacteria. Since in vitro measurements do not necessarily correlate with the in vivo action of a peptide we developed a novel fluorescent live bacteria lysis assay. Using fully functional nanoparticle-labeled Sushi 1, we observed the process of antimicrobial action at the single-molecule level. Conclusion Recently the hypothesis that many antimicrobial peptides act on internal targets to kill the bacterium has been discussed. Here, we demonstrate that the target sites of Sushi 1 are outer and inner membranes and are not cytosolic. Further, our findings

  20. Population dynamics of bacteria for phosphorus removal in sequencing batch reactor (SBR) activated sludge processes. Kaibunshiki kassei odeiho ni okeru datsu rin tokusei

    Okada, M.; Ueno, Y.; Lin, C.; Murakami, A. (Tokyo University of Agriculture and Technology, Tokyo (Japan))

    1990-01-10

    As the phosphorus removal processes, chemical methods and biological methods are considered. This paper discussed a biological phosphorus removal method. Laboratory experiments of phosphorus removal in sequencing batch reactor (SBR) activated sludge processes were operated using synthetic waste water to clarify the effects of solid retention time (SRT) and organic substrates on the accumulation of bacteria having phosphorus removal ability (bio-P-bacteria). The accumulation of bio-P-bacteria was enhanced by large fluctuation in concentration of organic substances in the reactor fed in a short period of time under anaerobic condition. However, the accumulation did not be enhanced in the reactor operated with SRT less than 25 d. The specific growth rates of bio-P-bacteria were estimated to a range from 0.033/d to 0.035/d in the SBR activated sludge processes fed with glucose and polypeptone as substrates. Therefore, large SRT is necessary for the accumulation of bio-P-bacteria. 18 refs., 10 figs., 1 tab.

  1. Identification of bacteria used for microbial enhanced oil recovery process by fluorescence in situ hybridization technique

    Fujiwara, K.; Tanaka, S.; Otsuka, M. [Kansai Research Institute, Kyoto (Japan). Lifescience Lab.; Yonebayashi, H. [Japan National Oil Corp., Chiba (Japan). Tech. Research Center; Enomoto, H. [Tohoku University, Sendai (Japan). Dept. of Geoscience and Tech.

    2000-01-01

    A fluorescence in situ hybridization (FISH) technique using 16S rRNA-targeted oligonucleotide probes was developed for rapid detection of microorganisms for use in the microbial enhancement of oil recovery (MEOR) process. Two microorganisms, Enterobacter cloacae TRC-322 and Bacillus licheniformis TRC-18-2-a, were selected from a collection of Enterobacter sp. and Bacillus sp. which were screened in previous studies as candidate microorganisms for injection, and were used for this experiment. Oligonucleotide probes, design based on specific sequences in the 16S rRNA gene were labeled with either fluorescein isothiocyanate (FITC), or 6-car-boxy-X-rhodamine (ROX), and were allowed to hybridize with fixed cells of the two microorganisms noted above. The fluorescence signal emitted from each microorganism cells could clearly be detected by an epifluorescence microscope. Moreover, E. cloacae TRC-322 and B, licheniformis TRC-18-2-a, suspended in actual reservoir brine, including inorganic salts, oil and aboriginal cells of the reservoir brine, could be detected directly by this hybridization method, without the need for cultivation and isolation. (author)

  2. Tumour lysis syndrome in children: experience of last decade.

    Ahn, Yo Han; Kang, Hyoung Jin; Shin, Hee Young; Ahn, Hyo Seop; Choi, Yong; Kang, Hee Gyung

    2011-12-01

    The strategy against tumour lysis syndrome (TLS) had been hyperhydration, urine alkalinization, and allopurinol. Recently, rasburicase was added to the armament against this life-threatening condition. In Korea, rasburicase is used as a rescue therapy for cases with allopurinol-resistant hyperuricemia, because of the restriction by the National Health Insurance. We reviewed our experiences to re-assess the risk factors of TLS and the efficacy of rasburicase. Medical records were retrospectively reviewed for 396 children who were diagnosed as positive with acute leukemia and non-Hodgkin lymphoma between the years 2000 and 2009. The risk factors for TLS were analyzed statistically, and those before and after the availability of rasburicase were compared. Sixty eight patients (17.2%) had TLS. Multivariate analysis showed that pre-chemotherapy hypophosphatemia was a risk factor for TLS, in addition to the known risk factors of hyperuricemia and high lactate dehydrogenase concentration. The availability of rasburicase as a rescue therapy did not negate the importance of uric acid as a risk factor of TLS. Rasburicase as a second line treatment for intractable hyperuricemia was not effective in reducing the incidence of TLS. Pre-chemotherapy hypophosphatemia was a significant independent risk factor for TLS. PMID:21710502

  3. The role of hydrogenotrophic iron-reducing bacteria on the corrosion process in the context of geological disposal

    The nuclear industry must to demonstrate the feasibility and safety of high level nuclear waste (HLNW) disposal. The generally recognised strategy for HLNW disposal is based on a multi-barrier system made by metallic packages surrounded by geological formation. The nuclear waste repository will be water re-saturated with time, and then the metallic corrosion process will take place. The aqueous corrosion will produce dihydrogen (H2) that represents a new energetic source (electron donor) for microbial development. Moreover, the formation of Fe(II,III) solid corrosion products, such as magnetite (Fe3O4), will provide electron acceptors favoring the development of iron-reducing bacteria (IRB). The activity of hydrogenotrophic and IRB can potentially alter the protective properties of passivating oxide layers (i.e. magnetite) which could reactivate corrosion. The main objective of this study is to evaluate the role of hydrogenotrophic and IRB activities on anoxic corrosion process by using geochemical indicators. Shewanella oneidensis strain MR-1 was chosen as model organism, and both abiotic and biotic conditions were investigated. In a first setup of experiments, our results indicate that synthetic magnetite is destabilized in the presence of hydrogenotrophic IRB due to structural Fe(III) reduction coupled to H2 oxidation. The extent of Fe(III) bioreduction is notably enhanced with the increase in the H2 concentration in the system: 4% H2 ≤ 10% H2 ≤ 60% H2. In a second setup of experiments, our results indicate that corrosion extent changes according to the solution composition and the surface of metallic sample (iron powder and carbon steel coupon). Moreover, the solid corrosion products are different for each sample: vivianite, siderite and chukanovite are the main mineral phases identified in the experiments with iron powder, while vivianite and magnetite are identified with carbon steel coupons. Our results demonstrate that corrosion rate is increased almost

  4. Screening of bacteria for self-healing of concrete cracks and optimization of the microbial calcium precipitation process.

    Zhang, J L; Wu, R S; Li, Y M; Zhong, J Y; Deng, X; Liu, B; Han, N X; Xing, F

    2016-08-01

    A novel high-throughput strategy was developed to determine the calcium precipitation activity (CPA) of mineralization bacteria used for self-healing of concrete cracks. A bacterial strain designated as H4 with the highest CPA of 94.8 % was screened and identified as a Bacillus species based on 16S rDNA sequence and phylogenetic tree analysis. Furthermore, the effects of certain influential factors on the microbial calcium precipitation process of H4 were evaluated. The results showed that lactate and nitrate are the best carbon and nitrogen sources, with optimal concentrations of approximately 25 and 18 mM, respectively. The H4 strain is able to maintain a high CPA in the pH range of 9.5-11.0, and a suitable initial spore concentration is 4.0 × 10(7) spores/ml. Moreover, an ambient Ca(2+) concentration greater than 60 mM resulted in a serious adverse impact not only on the CPA but also on the growth of H4, suggesting that the maintenance of the Ca(2+) concentration at a low level is necessary for microbial self-healing of concrete cracks. PMID:26883348

  5. Distribution of bacteria and yeasts within the 10-ml Isolator during the processing of seeded blood samples.

    Kellogg, J A; Levisky, J S

    1986-02-01

    Forty-five organisms consisting of stock cultures and clinical isolates of bacteria and yeast were separately inoculated into outdated blood bank blood to achieve a concentration of approximately 100 CFU/ml. Blood with each organism was introduced into groups of four Isolators (E. I. du Pont de Nemours & Co., Inc., Wilmington, Del.), which were then processed according to the Isostat instructions of the manufacturer. The supernatant, sediment, and wash (material removed from the surface of the slanted stopper after sediment removal) were inoculated onto 5% sheep blood agar plates. Cultures were incubated aerobically (5 to 10% CO2) at 35 degrees C for 48 to 72 h. From the 180 Isolators, the mean recovery was 6% (range, 0 to 48%) for the supernatant, 87% (range, 47 to 98%) for the sediment, and 8% (range, 3 to 23%) for the wash. Neither variation among technologists nor intentional misalignment of additional Isolators in the centrifuge could explain all of the losses of microorganisms from the sediment. The manual nature of the Isolator procedure, which led to the loss of significant amounts of organisms from the sediment, may help to explain false-negative Isolator results obtained from blood of patients, particularly when small numbers of pathogens are present. PMID:3084546

  6. Bioaugmentation of anaerobic sludge digestion with iron-reducing bacteria: process and microbial responses to variations in hydraulic retention time.

    Baek, Gahyun; Kim, Jaai; Shin, Seung Gu; Lee, Changsoo

    2016-01-01

    Although anaerobic digestion (AD) is a widely used option to manage waste activated sludge (WAS), there are some drawbacks related to its slow reaction rate and low energy productivity. This study examined an anaerobic WAS digester, augmented with an iron-reducing microbial consortium, relative to changes in microbial community structure and process performance at decreasing hydraulic retention times (HRTs) of 20 to 10 days. The enhanced methanation performance (approximately 40 % increase in methane yield) by the bioaugmentation was sustained until the HRT was decreased to 12.5 days, under Fe(3+)-rich conditions (ferric oxyhydroxide, 20 mM Fe). Enhanced iron-reducing activity was evidenced by the increased Fe(2+) to total Fe ratio maintained above 50 % during the stable operational phases. A further decrease in HRT to 10 days resulted in a significant performance deterioration, along with a drop in the Fe(2+) to total Fe ratio to <35 %, after four turnovers of operation. Prevailing existence of putative iron-reducing bacteria (IRBs) was identified by denaturing gradient gel electrophoresis (DGGE), with Spirochaetaceae- and Thauera-related organisms being dominant members, and clear dominance shifts among them with respect to decrease in HRT were observed. Lowering HRT led to evident shifts in bacterial community structure likely associated with washout of IRBs, leading to decreases in iron respiration activity and AD performance at a lower HRT. The bacterial community structure shifted dynamically over phases, and the community transitions correlated well with the changes in process performance. Overall, the combined biostimulation and bioaugmentation investigated in this study proved effective for enhanced methane recovery from anaerobic WAS digestion, which suggests an interesting potential for high-rate AD. PMID:26428233

  7. Modeling of kinetics of the inducible protein complexes of the SOS system in bacteria E. coli which realize TLS process

    The mathematical model describing kinetics of the inducible genes of the protein complexes, formed during SOS response in bacteria Escherichia coli is developed. Within the bounds of developed approaches the auxiliary mathematical model describing changes in concentrations of the dimers, which are the components of final protein complexes, is developed. The solutions of both models are based on the experimental data concerning expression of the basic genes of the SOS system in bacteria Escherichia coli

  8. Acid resistance of methanogenic bacteria in a two-stage anaerobic process treating high concentration methanol Wastewater

    ZHOU Xuefei; REN Nanqi

    2007-01-01

    In this study,the two-stage upflow anaerobic sludge blanket(UASB)system and batch experiments were employed to evaluate the performance of anaerobic digestion for the treatment of high concentration methanol wastewater.The acid resistance of granular sludge and methanogenic bacteria and their metabolizing activity were investigated.The results show that the pH of the first UASB changed from 4.9 to 5.8 and 5.5 to 6.2 for the second reactor.Apparently,these were not the advisable pH levels that common metha nogenic bacteria could accept.The methanogenic bacteria of the system,viz.Methanosarcina barkeri,had some acid resistance and could still degrade methanol at pH 5.0.If the methanogenic bacteria were trained further,their acid resistance would be improved somewhat.Granular sludge of the system could protect the methanogenic bacteria within its body against the impact of the acidic environment and make them degrade methanol at pH 4.5.The performance of granular sludge was attributed to its structure,bacteria species,and the distribution of bacterium inside the granule.

  9. Human mesenchymal stem cells are susceptible to lysis by CD8(+) T cells and NK cells.

    Crop, Meindert J; Korevaar, Sander S; de Kuiper, Ronella; IJzermans, Jan N M; van Besouw, Nicole M; Baan, Carla C; Weimar, Willem; Hoogduijn, Martin J

    2011-01-01

    There is growing interest in the use of mesenchymal stem cells (MSCs) to improve the outcome of organ transplantation. The immunogenicity of MSCs is, however, unclear and is important for the efficacy of MSC therapy and for potential sensitization against donor antigens. We investigated the susceptibility of autologous and allogeneic MSCs for lysis by CD8(+) T-lymphocytes and NK cells in a kidney transplant setting. MSCs were derived from adipose tissue of human kidney donors and were CD90(+), CD105(+), CD166(+), and HLA class I(+). They showed differentiation ability and immunosuppressive capacity. Lysis of MSCs by peripheral blood mononuclear cells (PBMCs), FACS-sorted CD8(+) T cells, and NK cells was measured by europium release assay. Allogeneic MSCs were susceptible for lysis by cytotoxic CD8(+) T cells and NK cells, while autologous MSCs were lysed by NK cells only. NK cell-mediated lysis was inversely correlated with the expression of HLA class I on MSCs. Lysis of autologous MSCs was not dependent on culturing of MSCs in FBS, and MSCs in suspension as well as adherent to plastic were lysed by NK cells. Pretransplant recipient PBMCs did not lyse donor MSCs, but PBMCs isolated 3, 6, and 12 months after transplantation showed increasing lysing ability. After 12 months, CD8(+) T-cell-mediated lysis of donor MSCs persisted, indicating there was no evidence for desensitization against donor MSCs. Lysis of MSCs is important to take into account when MSCs are considered for clinical application. Our results suggest that the HLA background of MSCs and timing of MSC administration are important for the efficacy of MSC therapy. PMID:21396164

  10. Evaluation of cell lysis procedures and use of a micro fluidic system for an automated DNA-based cell identification in interplanetary missions

    Hall, J. A.; Felnagle, E.; Fries, M.; Spearing, S.; Monaco, L.; Steele, A.

    2006-12-01

    A Modular Assay System for Solar System Exploration (MASSE) is being developed to include sample handling, pre-treatment, separation and analysis of biological target compounds by both DNA and protein microarrays. To better design sensitive and accurate initial upstream sample handling of the MASSE instrument, experiments investigating the sensitivity and potential extraction bias of commercially available DNA extraction kits between classes of environmentally relevant prokaryotes such as gram-negative bacteria ( Escherichia coli), gram-positive bacteria ( Bacillus megatarium), and Archaea ( Haloarcula marismortui) were performed. For extractions of both planktonic cultures and spiked Mars simulated regolith, FTA ® paper demonstrated the highest sensitivity, with detection as low as ˜1×10 1 cells and ˜3.3×10 2 cells, respectively. In addition to the highest sensitivity, custom modified application of FTA ® paper extraction protocol is the simplest in terms of incorporation into MASSE and displayed little bias in sensitivity with respect to prokaryotic cell type. The implementation of FTA paper for environmental microbiology investigations appears to be a viable and effective option potentially negating the need for other pre-concentration steps such as filtration and negating concerns regarding extraction efficiency of cells. In addition to investigations on useful technology for upstream sample handling in MASSE, we have also evaluated the potential for μTAS to be employed in the MASSE instrument by employing proprietary lab-on-a-chip development technology to investigate the potential for microfluidic cell lysis of different prokaryotic cells employing both chemical and biological lysis agents. Real-time bright-field microscopy and quantitative PMT detection indicated that that gram positive, gram negative and archaeal cells were effectively lyzed in a few seconds using the microfluidic chip protocol developed. This included employing a lysis buffer with

  11. In vitro clot lysis as a potential indicator of thrombus resistance to fibrinolysis--study in healthy subjects and correlation with blood fibrinolytic parameters.

    Colucci, M; Scopece, S; Gelato, A V; Dimonte, D; Semeraro, N

    1997-04-01

    Using an in vitro model of clot lysis, the individual response to a pharmacological concentration of recombinant tissue plasminogen activator (rt-PA) and the influence on this response of the physiological variations of blood parameters known to interfere with the fibrinolytic/thrombolytic process were investigated in 103 healthy donors. 125I-fibrin labelled blood clots were submersed in autologous plasma, supplemented with 500 ng/ml of rt-PA or solvent, and the degree of lysis was determined after 3 h of incubation at 37 degrees C. Baseline plasma levels of t-PA, plasminogen activator inhibitor 1 (PAI-1), plasminogen, alpha 2-antiplasmin, fibrinogen, lipoprotein (a), thrombomodulin and von Willebrand factor as well as platelet and leukocyte count and clot retraction were also determined in each donor. rt-PA-induced clot lysis varied over a wide range (28-75%) and was significantly related to endogenous t-PA, PAI-1, plasminogen (p < 0.001) and age (p < 0.01). Multivariate analysis indicated that both PAI-1 antigen and plasminogen independently predicted low response to rt-PA. Surprisingly, however, not only PAI-1 but also plasminogen was negatively correlated with rt-PA-induced clot lysis. The observation that neutralization of PAI-1 by specific antibodies, both in plasma and within the clot, did not potentiate clot lysis indicates that the inhibitor, including the platelet-derived form, is insufficient to attenuate the thrombolytic activity of a pharmacological concentration of rt-PA and that its elevation, similarly to the elevation of plasminogen, is not the cause of clot resistance but rather a coincident finding. It is concluded that the in vitro response of blood clots to rt-PA is poorly influenced by the physiological variations of the examined parameters and that factors other than those evaluated in this study interfere with clot dissolution by rt-PA. In vitro clot lysis test might help to identify patients who may be resistant to thrombolytic therapy

  12. Methanotrophic bacteria.

    Hanson, R S; Hanson, T. E.

    1996-01-01

    Methane-utilizing bacteria (methanotrophs) are a diverse group of gram-negative bacteria that are related to other members of the Proteobacteria. These bacteria are classified into three groups based on the pathways used for assimilation of formaldehyde, the major source of cell carbon, and other physiological and morphological features. The type I and type X methanotrophs are found within the gamma subdivision of the Proteobacteria and employ the ribulose monophosphate pathway for formaldehy...

  13. Radiation-induced enhancement of enzymatic cell lysis of Micrococcus radiodurans

    The intact cells of M. radiodurans were rendered sensitive to the action of lytic enzyme (P2-2 enzyme) by irradiation. The radiation-induced enhancement of cell lysis with P2-2 enzyme was completely prevented by the addition of t-butanol and irradiation at liquid nitrogen temperature. These results indicate that the enhancement is due to indirect action resulting from OH radicals. Cell lysis by lysozyme was enhanced only when the cells were irradiated under N2O. The enhancement of cell lysis with lysozyme was also prevented by adding alcohols. On the other hand, when lipid components in cells were removed by extraction with n-butanol, the radiation-induced enhancement of cell lysis with P2-2 enzyme and lysozyme was not observed. From these results it is concluded that the enhancement of enzymatic cell lysis by irradiation is attributable to alteration in the lipid-rich layer of the cell wall caused by OH radicals

  14. Numerical Simulation of Rheological, Chemical and Hydromechanical Processes of Thrombolysis

    Khramchenkov, E.; Khramchenkov, M.

    2015-04-01

    Mathematical model of clot lysis in blood vessels is developed on the basis of equations of convection-diffusion. Fibrin of the clot is considered stationary solid phase, and plasminogen, plasmin and plasminogen-activators - as dissolved fluid phases. As a result of numerical solution of the model predictions of lysis process are gained. Important influence of clot swelling on the process of lysis is revealed.

  15. Investigation of antibacterial activity of supercritical extracts of plants, as well as of extracts obtained by other technological processes on some bacteria isolated from animals

    Mišić Dušan; Ašanin Ružica; Ivanović Jasna; Žižović Irena

    2009-01-01

    The multiresistance of bacteria to antibiotics, as well as the lack of new antibiotics on the market encouraged the research of antibacterial activity of non-antibiotic substances including plant extracts. During the previous decades, it has been proven that extracts of certain plants have a strong antibacterial activity, but their clinical use was limited due to the presence of organic solvents. However, plant extracts obtained by the process of supercritical fluid extraction contain no trac...

  16. Cell lysis induced by membrane-damaging detergent saponins from Quillaja saponaria.

    Berlowska, Joanna; Dudkiewicz, Marta; Kregiel, Dorota; Czyzowska, Agata; Witonska, Izabela

    2015-01-01

    This paper presents the results of a study to determine the effect of Quillaja saponaria saponins on the lysis of industrial yeast strains. Cell lysis induced by saponin from Q. saponaria combined with the plasmolysing effect of 5% NaCl for Saccharomyces cerevisiae, Kluyveromyces marxianus yeasts biomass was conducted at 50 °C for 24-48 h. Membrane permeability and integrity of the yeast cells were monitored using fluorescent techniques and concentrations of proteins, free amino nitrogen (FAN) and free amino acids in resulting lysates were analyzed. Protein release was significantly higher in the case of yeast cell lysis promoted with 0.008% Q. saponaria and 5% NaCl in comparison to plasmolysis triggered by NaCl only. PMID:26047915

  17. Kinetic Model of the Lysogeny/Lysis Switch of Phage λ

    A kinetic model of the interactions between operators and regulators is developed to study the stabilities of genetic states and lysogeny/lysis switch in Escherichia coli infected by bacteriophage lambda. Using adiabatic approximation, the kinetic evolutions of mRNA and regulator concentrations can be deduced from operators' equations. Furthermore, the stability of each state of the system is studied. The results show that the lysogenic state switches to the lytic state through two bifurcations: one from a single stable state to a three-point state, and the other from a three-point state to a single stable state. Then we indicate that the property of the lysogeny/lysis switch satisfies the topological characteristics theorem. Finally, the influence of the left operators on the lysogeny/lysis switch is briefly discussed. The results show that the cooperativity of the CI2 bound to left and right operators makes the lysogenic state more stable

  18. Kinetic Model of the Lysogeny/Lysis Switch of Phage λ

    Ding, Hui; Luo, Liao-Fu

    2009-09-01

    A kinetic model of the interactions between operators and regulators is developed to study the stabilities of genetic states and lysogeny/lysis switch in Escherichia coli infected by bacteriophage lambda. Using adiabatic approximation, the kinetic evolutions of mRNA and regulator concentrations can be deduced from operators' equations. Furthermore, the stability of each state of the system is studied. The results show that the lysogenic state switches to the lytic state through two bifurcations: one from a single stable state to a three-point state, and the other from a three-point state to a single stable state. Then we indicate that the property of the lysogeny/lysis switch satisfies the topological characteristics theorem. Finally, the influence of the left operators on the lysogeny/lysis switch is briefly discussed. The results show that the cooperativity of the CI2 bound to left and right operators makes the lysogenic state more stable.

  19. Preventing acute renal failure is crucial during acute tumor lysis syndrome

    Darmon Michael

    2007-01-01

    Full Text Available Tumour Lysis syndrome (TLS is characterized by the massive destruction of tumoral cells and the release in the extracellular space of their content. While TLS may occur spontaneously before treatment, it usually develops shortly after the initiation of cytotoxic chemotherapy. These metabolites can overwhelm the homeostatic mechanisms and cause hyperuricemia, hyperkalemia, hyperphosphatemia and hypocalcemia. Moreover, TLS may lead to an acute renal failure (ARF. In addition to the hospital mortality induced by the acute renal failure itself, development of an ARF may preclude optimal cancer treatment. Therefore, prevention of the acute renal failure during acute tumor lysis syndrome is mandatory. The objective of this review is to describe pathophysiological mechanisms leading to acute tumor lysis syndrome, clinical and biological consequences of this syndrome and to provide up-to-date guidelines to ensure prevention and prompt management of this syndrome.

  20. Lysis of a Single Cyanobacterium for Whole Genome Amplification

    Richard N. Zare

    2013-08-01

    Full Text Available Bacterial species from natural environments, exhibiting a great degree of genetic diversity that has yet to be characterized, pose a specific challenge to whole genome amplification (WGA from single cells. A major challenge is establishing an effective, compatible, and controlled lysis protocol. We present a novel lysis protocol that can be used to extract genomic information from a single cyanobacterium of Synechocystis sp. PCC 6803 known to have multilayer cell wall structures that resist conventional lysis methods. Simple but effective strategies for releasing genomic DNA from captured cells while retaining cellular identities for single-cell analysis are presented. Successful sequencing of genetic elements from single-cell amplicons prepared by multiple displacement amplification (MDA is demonstrated for selected genes (15 loci nearly equally spaced throughout the main chromosome.

  1. Seasonal variations of virus- and nanoflagellate-mediated mortality of heterotrophic bacteria in the coastal ecosystem of subtropical western Pacific

    A. Y. Tsai

    2013-05-01

    Full Text Available Since viral lysis and nanoflagellate grazing differ in their impact on the aquatic food web, it is important to assess the relative importance of both bacterial mortality factors. In this study, an adapted version of the modified dilution method was applied to simultaneously estimate the impact of both virus and nanoflagellate grazing on the mortality of heterotrophic bacteria. A series of experiments was conducted monthly from April to December 2011 and April to October 2012. The growth rates of bacteria we measured ranged from 0.078 h−1 (April 2011 to 0.42 h−1 (September 2011, indicating that temperature can be important in controlling the seasonal variations of bacterial growth. Furthermore, it appeared that seasonal changes in nanoflagellate grazing and viral lysis could account for 34% to 68% and 13% to 138% of the daily removal of bacterial production, respectively. We suggest that nanoflagellate grazing might play a key role in controlling bacterial biomass and might exceed the impact of viral lysis during the summer period (July to August because of the higher abundance of nanoflagellates at that time. Viral lysis, on the other hand, was identified as the main cause of bacterial mortality between September and December. Based on these findings in this study, the seasonal variations in bacterial abundance we observed can be explained by a scenario in which both growth rates and loss rates (grazing + viral lysis influence the dynamics of the bacteria community.

  2. Tumor lysis syndrome and acute anemia in an African-American man with chronic lymphocytic leukemia

    Zhang, Bingnan; Lee, Alfred Ian; Podoltsev, Nikolai

    2014-01-01

    Tumor lysis syndrome (TLS) is a life-threating hematologic emergency caused by massive lysis of tumor cells into the blood stream. TLS can be prevented and treated with rasburicase. Rasburicase-induced hemolysis and methemoglobinemia is a rare but serious complication. Screening for G6PD should be considered for patients at higher risk for G6PD deficiency who may be also at high risk for TLS on the basis of clinical parameters. G6PD level in G6PD-deficient patients may be normal during an acu...

  3. Tumor lysis syndrome following endoscopic radiofrequency interstitial thermal ablation of colorectal liver metastases.

    Barry, B D

    2012-02-03

    Radiofrequency interstitial thermal ablation (RITA) provides a palliative option for patients suffering from metastatic liver disease. This procedure can be performed using a laparoscopic approach with laparoscopic ultrasound used to position the RITA probe. We describe a case of laparoscopic RITA performed for colorectal liver metastasis that was complicated by tumor lysis syndrome (TLS) following treatment. We consider RITA to be a safe procedure, as supported by the literature, but where intracorporal tumor lysis is the treatment goal we believe that the systemic release of tumor products can overwhelm the excretory capacity; therefore, TLS is an inevitable consequence in some patients.

  4. Complement lysis activity in autologous plasma is associated with lower viral loads during the acute phase of HIV-1 infection.

    Michael Huber

    2006-11-01

    Full Text Available BACKGROUND: To explore the possibility that antibody-mediated complement lysis contributes to viremia control in HIV-1 infection, we measured the activity of patient plasma in mediating complement lysis of autologous primary virus. METHODS AND FINDINGS: Sera from two groups of patients-25 with acute HIV-1 infection and 31 with chronic infection-were used in this study. We developed a novel real-time PCR-based assay strategy that allows reliable and sensitive quantification of virus lysis by complement. Plasma derived at the time of virus isolation induced complement lysis of the autologous virus isolate in the majority of patients. Overall lysis activity against the autologous virus and the heterologous primary virus strain JR-FL was higher at chronic disease stages than during the acute phase. Most strikingly, we found that plasma virus load levels during the acute but not the chronic infection phase correlated inversely with the autologous complement lysis activity. Antibody reactivity to the envelope (Env proteins gp120 and gp41 were positively correlated with the lysis activity against JR-FL, indicating that anti-Env responses mediated complement lysis. Neutralization and complement lysis activity against autologous viruses were not associated, suggesting that complement lysis is predominantly caused by non-neutralizing antibodies. CONCLUSIONS: Collectively our data provide evidence that antibody-mediated complement virion lysis develops rapidly and is effective early in the course of infection; thus it should be considered a parameter that, in concert with other immune functions, steers viremia control in vivo.

  5. Processing of humic-rich riverine dissolved organic matter by estuarine bacteria: effects of predegradation and inorganic nutrients

    Asmala, E.; Autio, R.; Kaartokallio, H.;

    2014-01-01

    The bioavailability of predegraded dissolved organic matter (DOM) from a humic-rich, boreal river to estuarine bacteria from the Baltic Sea was studied in 39-day bioassays. The river waters had been exposed to various degrees of bacterial degradation by storing them between 0 and 465 days in dark...... prior to the bioassay. The resulting predegraded DOM was inoculated with estuarine bacteria and the subsequent changes in DOM quantity and quality measured. During the incubations, dissolved organic carbon (DOC) and oxygen concentrations decreased, indicating heterotrophic activity. Coloured DOM...... was degraded less than DOC, indicating a selective utilization of DOM, and humic-like fluorescence components increased during the incubations. The amount of DOC degraded was not affected by the length of DOM predegradation. The percentage of bioavailable DOC (%BDOC) was higher in experiment units with added...

  6. Investigation of lactic acid bacteria mediated bioprotection with applications in cereal industry. Case-study: malting process

    Oliveira, Pedro Miguel Rodrigues

    2014-01-01

    Antifungal compounds produced by Lactic acid bacteria (LAB) metabolites can be natural and reliable alternative for reducing fungal infections pre- and post-harvest with a multitude of additional advantages for cereal-base products. Toxigenic and spoilage fungi are responsible for numerous diseases and economic losses. This thesis includes an overview of the impact fungi have on aspects of the cereal food chain. The applicability of LAB in plant protection and cereal industry is discussed in ...

  7. Lactic Acid Bacteria as protective and functional cultures for the enhancement of chestnut (Castanea sativa Mill.) processing chain

    Di Capua, Marika

    2015-01-01

    Chestnuts are very perishable fruits, whose quality may be compromised during postharvest handling. Damage can be caused both by insects and fungi. Water curing, a commonly used postharvest method, is based on soaking fruits in water typically for about one week. Factors that affect effectiveness of water curing have only been explained partially. A decrease in pH, likely imputable to a light fermentation caused by lactic acid bacteria, may inhibit the growth of moulds. In this study a Lac...

  8. 蔬菜腌制及其乳酸菌技术的研究进展%Pickling Process of Vegetables and its Lactic Acid Bacteria Technology

    吴祖芳; 赵永威; 翁佩芳

    2012-01-01

    Pickled vegetables processing is an important part of the vegetable processing industry. With the gradual deepening developing of lactic acid bacteria research and new technologies of agricultural products processing, one of the great research interests-was focused on the study of pickled vegetables process. In this paper, the microbial diversity, metabolite of lactic bacteria and flavor compound formation, the functional properties evaluations as well as the ferment starter application of pickled vegetables were elucidated among the domestic and foreign research progress. This can provide the references for technology development and research of pickled vegetables processing.%蔬菜腌制加工是蔬菜加工产业中的重要组成部分,随着农产品加工新技术及乳酸菌研究的逐步深入和发展,腌制蔬菜也成为一个新的研究热点.作者分析了国内外有关蔬菜腌制过程中微生态、乳酸菌的代谢及其蔬菜腌制风味发生机制、腌制蔬菜功能特性评价以及发酵剂开发等方面的研究进展,为蔬菜腌制技术的发展等提供参考.

  9. Big bacteria

    Schulz, HN; Jørgensen, BB

    2001-01-01

    A small number of prokaryotic species have a unique physiology or ecology related to their development of unusually large size. The biomass of bacteria varies over more than 10 orders of magnitude, from the 0.2 mum wide nanobacteria to the largest cells of the colorless sulfur bacteria......, Thiomargarita namibiensis, with a diameter of 750 mum. All bacteria, including those that swim around in the environment, obtain their food molecules by molecular diffusion. Only the fastest and largest swimmers known, Thiovulum majus, are able to significantly increase their food supply by motility and by...... actively creating an advective flow through the entire population. Diffusion limitation generally restricts the maximal size of prokaryotic cells and provides a selective advantage for mum-sized cells at the normally low substrate concentrations in the environment. The largest heterotrophic bacteria, the...

  10. Anaerobic bacteria

    Brook I, Goldstein EJ. Diseases caused by non-spore forming anaerobic bacteria. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 297. Stedman's Online ...

  11. Electrochemical lysis at the stage of endoresection for large posterior intraocular tumors

    Yu. A. Belyy

    2014-07-01

    Full Text Available Purpose: to design the new combined technique of endoresection with intraoperative intraocular electrochemical lysis at the tumor destruction stage for large posterior intraocular tumors.Methods: 3 patients (3 eyes with large choroidal melanomas t3N0M0 (tumor thickness — 8-10 mm, base diameter — 13-15 mm, juxtapapillary localization. Mean age was 55.4 years old. Endoresection with intraoperational intraocular electrochemical lysis of the tumor was performed. Electrochemical lysis was performed with use of the technical unit ECU 300 (Soering, Germany and the original method of combined intratumoral positioning of two platinum electrodes: anode and cathode.Results: the tumor was removal completely in all 3 cases. the anatomical retinal reattachment was reached in all patients. Sclera was safe in all 3 cases. Visual acuity was not changed (NLP. At the place of the removal tumor a surgical choroidal coloboma without pigmentation all over scleral bed and periphery was shown in all cases in distant postoperative period (from 1.5 to 3 years. No local recurrences or metastasis were revealed in all patients.Conclusion: Further investigations in clinical group are necessarily to determinate the real possibilities of the combined method and the indications for endoresection with intraoperative intraocular electrochemical lysis for large intraocular tumors. 

  12. Quantifying enzymatic lysis: estimating the combined effects of chemistry, physiology and physics

    The number of microbial pathogens resistant to antibiotics continues to increase even as the rate of discovery and approval of new antibiotic therapeutics steadily decreases. Many researchers have begun to investigate the therapeutic potential of naturally occurring lytic enzymes as an alternative to traditional antibiotics. However, direct characterization of lytic enzymes using techniques based on synthetic substrates is often difficult because lytic enzymes bind to the complex superstructure of intact cell walls. Here we present a new standard for the analysis of lytic enzymes based on turbidity assays which allow us to probe the dynamics of lysis without preparing a synthetic substrate. The challenge in the analysis of these assays is to infer the microscopic details of lysis from macroscopic turbidity data. We propose a model of enzymatic lysis that integrates the chemistry responsible for bond cleavage with the physical mechanisms leading to cell wall failure. We then present a solution to an inverse problem in which we estimate reaction rate constants and the heterogeneous susceptibility to lysis among target cells. We validate our model given simulated and experimental turbidity assays. The ability to estimate reaction rate constants for lytic enzymes will facilitate their biochemical characterization and development as antimicrobial therapeutics

  13. A simple and novel modification of comet assay for determination of bacteriophage mediated bacterial cell lysis.

    Khairnar, Krishna; Sanmukh, Swapnil; Chandekar, Rajshree; Paunikar, Waman

    2014-07-01

    The comet assay is the widely used method for in vitro toxicity testing which is also an alternative to the use of animal models for in vivo testing. Since, its inception in 1984 by Ostling and Johansson, it is being modified frequently for a wide range of application. In spite of its wide applicability, unfortunately there is no report of its application in bacteriophages research. In this study, a novel application of comet assay for the detection of bacteriophage mediated bacterial cell lysis was described. The conventional methods in bacteriophage research for studying bacterial lysis by bacteriophages are plaque assay method. It is time consuming, laborious and costly. The lytic activity of bacteriophage devours the bacterial cell which results in the release of bacterial genomic material that gets detected by ethidium bromide staining method by the comet assay protocol. The objective of this study was to compare efficacy of comet assay with different assay used to study phage mediated bacterial lysis. The assay was performed on culture isolates (N=80 studies), modified comet assay appear to have relatively higher sensitivity and specificity than other assay. The results of the study showed that the application of comet assay can be an economical, time saving and less laborious alternative to conventional plaque assay for the detection of bacteriophage mediated bacterial cell lysis. PMID:24681053

  14. Single-Cell Electric Lysis on an Electroosmotic-Driven Microfluidic Chip with Arrays of Microwells

    Yu-Hung Chen

    2012-05-01

    Full Text Available Accurate analysis at the single-cell level has become a highly attractive tool for investigating cellular content. An electroosmotic-driven microfluidic chip with arrays of 30-µm-diameter microwells was developed for single-cell electric lysis in the present study. The cellular occupancy in the microwells when the applied voltage was 5 V (82.4% was slightly higher than that at an applied voltage of 10 V (81.8%. When the applied voltage was increased to 15 V, the cellular occupancy in the microwells dropped to 64.3%. More than 50% of the occupied microwells contain individual cells. The results of electric lysis experiments at the single-cell level indicate that the cells were gradually lysed as the DC voltage of 30 V was applied; the cell was fully lysed after 25 s. Single-cell electric lysis was demonstrated in the proposed microfluidic chip, which is suitable for high-throughput cell lysis.

  15. Hypochlorite- and hypobromite-mediated radical formation and its role in cell lysis

    Hawkins, C L; Brown, B E; Davies, Michael Jonathan

    2001-01-01

    Activated leukocytes generate the potent oxidants HOCl and HOBr via the formation of H(2)O(2) and the release of peroxidase enzymes (myeloperoxidase, eosinophil peroxidase). HOCl and HOBr are potent microbiocidal agents, but excessive or misplaced production can cause tissue damage and cell lysis...

  16. Genetically Determined Variation in Lysis Time Variance in the Bacteriophage φX174

    Christopher W. Baker

    2016-04-01

    Full Text Available Researchers in evolutionary genetics recently have recognized an exciting opportunity in decomposing beneficial mutations into their proximal, mechanistic determinants. The application of methods and concepts from molecular biology and life history theory to studies of lytic bacteriophages (phages has allowed them to understand how natural selection sees mutations influencing life history. This work motivated the research presented here, in which we explored whether, under consistent experimental conditions, small differences in the genome of bacteriophage φX174 could lead to altered life history phenotypes among a panel of eight genetically distinct clones. We assessed the clones’ phenotypes by applying a novel statistical framework to the results of a serially sampled parallel infection assay, in which we simultaneously inoculated each of a large number of replicate host volumes with ∼1 phage particle. We sequentially plated the volumes over the course of infection and counted the plaques that formed after incubation. These counts served as a proxy for the number of phage particles in a single volume as a function of time. From repeated assays, we inferred significant, genetically determined heterogeneity in lysis time and burst size, including lysis time variance. These findings are interesting in light of the genetic and phenotypic constraints on the single-protein lysis mechanism of φX174. We speculate briefly on the mechanisms underlying our results, and we discuss the potential importance of lysis time variance in viral evolution.

  17. Inhibiting mild steel corrosion from sulfate-reducing bacteria using antimicrobial-producing biofilms in Three-Mile-Island process water.

    Zuo, R; Ornek, D; Syrett, B C; Green, R M; Hsu, C-H; Mansfeld, F B; Wood, T K

    2004-04-01

    Biofilms were used to produce gramicidin S (a cyclic decapeptide) to inhibit corrosion-causing, sulfate-reducing bacteria (SRB). In laboratory studies these biofilms protected mild steel 1010 continuously from corrosion in the aggressive, cooling service water of the AmerGen Three-Mile-Island (TMI) nuclear plant, which was augmented with reference SRB. The growth of both reference SRB (Gram-positive Desulfosporosinus orientis and Gram-negative Desulfovibrio vulgaris) was shown to be inhibited by supernatants of the gramicidin-S-producing bacteria as well as by purified gramicidin S. Electrochemical impedance spectroscopy and mass loss measurements showed that the protective biofilms decreased the corrosion rate of mild steel by 2- to 10-fold when challenged with the natural SRB of the TMI process water supplemented with D. orientis or D. vulgaris. The relative corrosion inhibition efficiency was 50-90% in continuous reactors, compared to a biofilm control which did not produce the antimicrobial gramicidin S. Scanning electron microscope and reactor images also revealed that SRB attack was thwarted by protective biofilms that secrete gramicidin S. A consortium of beneficial bacteria (GGPST consortium, producing gramicidin S and other antimicrobials) also protected the mild steel. PMID:12898064

  18. Immunosuppressive and carcinogenic effect of UV light; Apoptosis and lysis of mouse spleen cells

    Harmful effects of UV light involves cell killing, mutagenesis and neoplastic transformation of exposed cells. The effect of UV light depends on the wavelength, dose irradiation, type of exposed cells, endogeny substance, experimental condition that can increase or decrease sensibility of the cells on the UV light. The loss of viability is the end point of cellular dysfunction, however, UV irradiation may affect cells function before it is perish. We examined the killing modes of cell death, necrosis or apoptosis, depending on the way of the cellular elements involved in process. Necrosis is a pothologic response involving a dramatic increase in cell volume that ultimately leads to cell lysis, usually caused by damaging of cell membrane. Apoptosis or genetically programmed cell death is result of complex cell mechanisms. Mouse spleen cells were diluted to 8.5·106/mL in Hanks' solution. Cells spread in thin layers (2mm) in glass Petri dishes were exposed to the different doses of UVC light. After irradiation and staining with fluorescein diacetate (FDA) and propidium iodide (PI) solution, the viable cells, as well as apoptosis were observed under fluorescent microscope. Immediately after UV irradiation the number of viable cell rapidly decreased. Lower doses of UVC light caused apoptosis as well as necrosis of exposed cells. Around 10% of spleen cells commit suicide after UVC exposure. There was significantly higher percentage of apoptotic cell than in control non irradiated sample. The highest fluence (1280J/m2) of UVC light, lysed considerable number of lymphocytes, around 80%. Small fraction (15%) of cells survived used UVC light. Noticed resistance of spleen cells is not completely clear, but results suggest that it due to the present of mature lymphocytes, which could not proliferate, and are less sensitive to UV light. In spite of this our results confirm that UVC light is capable to cause DNA damage, apoptosis and necrosis of mouse spleen cells. (author)

  19. Fractalkine expression induces endothelial progenitor cell lysis by natural killer cells.

    Dilyana Todorova

    Full Text Available BACKGROUND: Circulating CD34(+ cells, a population that includes endothelial progenitors, participate in the maintenance of endothelial integrity. Better understanding of the mechanisms that regulate their survival is crucial to improve their regenerative activity in cardiovascular and renal diseases. Chemokine-receptor cross talk is critical in regulating cell homeostasis. We hypothesized that cell surface expression of the chemokine fractalkine (FKN could target progenitor cell injury by Natural Killer (NK cells, thereby limiting their availability for vascular repair. METHODOLOGY/PRINCIPAL FINDINGS: We show that CD34(+-derived Endothelial Colony Forming Cells (ECFC can express FKN in response to TNF-α and IFN-γ inflammatory cytokines and that FKN expression by ECFC stimulates NK cell adhesion, NK cell-mediated ECFC lysis and microparticles release in vitro. The specific involvement of membrane FKN in these processes was demonstrated using FKN-transfected ECFC and anti-FKN blocking antibody. FKN expression was also evidenced on circulating CD34(+ progenitor cells and was detected at higher frequency in kidney transplant recipients, when compared to healthy controls. The proportion of CD34(+ cells expressing FKN was identified as an independent variable inversely correlated to CD34(+ progenitor cell count. We further showed that treatment of CD34(+ circulating cells isolated from adult blood donors with transplant serum or TNF-α/IFN-γ can induce FKN expression. CONCLUSIONS: Our data highlights a novel mechanism by which FKN expression on CD34(+ progenitor cells may target their NK cell mediated killing and participate to their immune depletion in transplant recipients. Considering the numerous diseased contexts shown to promote FKN expression, our data identify FKN as a hallmark of altered progenitor cell homeostasis with potential implications in better evaluation of vascular repair in patients.

  20. Method and apparatus for iterative lysis and extraction of algae

    Chew, Geoffrey; Boggs, Tabitha; Dykes, Jr., H. Waite H.; Doherty, Stephen J.

    2015-12-01

    A method and system for processing algae involves the use of an ionic liquid-containing clarified cell lysate to lyse algae cells. The resulting crude cell lysate may be clarified and subsequently used to lyse algae cells. The process may be repeated a number of times before a clarified lysate is separated into lipid and aqueous phases for further processing and/or purification of desired products.

  1. Primary structure and functional analysis of the lysis genes of Lactobacillus gasseri bacteriophage phi adh.

    Henrich, B; Binishofer, B; Bläsi, U

    1995-02-01

    The lysis genes of the Lactobacillus gasseri bacteriophage phi adh were isolated by complementation of a lambda Sam mutation in Escherichia coli. Nucleotide sequencing of a 1,735-bp DNA fragment revealed two adjacent coding regions of 342 bp (hol) and 951 bp (lys) in the same reading frame which appear to belong to a common transcriptional unit. Proteins corresponding to the predicted gene products, holin (12.9 kDa) and lysin (34.7 kDa), were identified by in vitro and in vivo expression of the cloned genes. The phi adh holin is a membrane-bound protein with structural similarity to lysis proteins of other phage, known to be required for the transit of murein hydrolases through the cytoplasmic membrane. The phi adh lysin shows homology with mureinolytic enzymes encoded by the Lactobacillus bulgaricus phage mv4, the Streptococcus pneumoniae phage Cp-1, Cp-7, and Cp-9, and the Lactococcus lactis phage phi LC3. Significant homology with the N termini of known muramidases suggests that phi adh lysin acts by a similar catalytic mechanism. In E. coli, the phi adh lysin seems to be associated with the total membrane fraction, from which it can be extracted with lauryl sarcosinate. Either one of the phi adh lysis proteins provoked lysis of E. coli when expressed along with holins or lysins of phage lambda or Bacillus subtilis phage phi 29. Concomitant expression of the combined holin and lysin functions of phi adh in E. coli, however, did not result in efficient cell lysis. PMID:7836307

  2. Organic carbon recovery and photosynthetic bacteria population in an anaerobic membrane photo-bioreactor treating food processing wastewater.

    Chitapornpan, S; Chiemchaisri, C; Chiemchaisri, W; Honda, R; Yamamoto, K

    2013-08-01

    Purple non-sulfur bacteria (PNSB) were cultivated by food industry wastewater in the anaerobic membrane photo-bioreactor. Organic removal and biomass production and characteristics were accomplished via an explicit examination of the long term performance of the photo-bioreactor fed with real wastewater. With the support of infra-red light transmitting filter, PNSB could survive and maintain in the system even under the continual fluctuations of influent wastewater characteristics. The average BOD and COD removal efficiencies were found at the moderate range of 51% and 58%, respectively. Observed photosynthetic biomass yield was 0.6g dried solid/g BOD with crude protein content of 0.41 g/g dried solid. Denaturing gradient gel electrophoretic analysis (DGGE) and 16S rDNA sequencing revealed the presence of Rhodopseudomonas palustris and significant changes in the photosynthetic bacterial community within the system. PMID:23489563

  3. Isolation and Identification of Concrete Environment Bacteria

    Irwan, J. M.; Anneza, L. H.; Othman, N.; Husnul, T.; Alshalif, A. F.

    2016-07-01

    This paper presents the isolation and molecular method for bacteria identification through PCR and DNA sequencing. Identification of the bacteria species is required in order to fully utilize the bacterium capability for precipitation of calcium carbonate in concrete. This process is to enable the addition of suitable catalyst according to the bacterium enzymatic pathway that is known through the bacteria species used. The objective of this study is to isolate, enriched and identify the bacteria species. The bacteria in this study was isolated from fresh urine and acid mine drainage water, Kota Tinggi, Johor. Enrichment of the isolated bacteria was conducted to ensure the bacteria survivability in concrete. The identification of bacteria species was done through polymerase chain reaction (PCR) and rRDNA sequencing. The isolation and enrichment of the bacteria was done successfully. Whereas, the results for bacteria identification showed that the isolated bacteria strains are Bacillus sp and Enterococus faecalis.

  4. Isolation of anoxygenic photosynthetic bacteria from Songkhla Lake for use in a two-staged biohydrogen production process from palm oil mill effluent

    Suwansaard, Maneewan; Prasertsan, Poonsuk [Department of Industrial Biotechnology, Faculty of Agro-Industry, Prince of Songkla University, Songkla 90112 (Thailand); Choorit, Wanna [School of Agricultural Technology, Walailak University, Nakhonsithammarat 80160 (Thailand); Zeilstra-Ryalls, Jill H. [Department of Biological Sciences, Bowling Green State University, Bowling Green, Ohio 43403 (United States)

    2009-09-15

    We are developing a process to produce biohydrogen from palm oil mill effluent. Part of this process will involve photohydrogen production from volatile fatty acids under low light conditions. We sought to isolate suitable bacteria for this purpose from Songkhla Lake in Southern Thailand. Enrichment for phototrophic bacteria from 34 samples was conducted providing acetate as a major carbon source and applying culturing conditions of anaerobic-low light (3000 lux) at 30 C. Among the independent isolates from these enrichments 19 evolved hydrogen with productivities between 4 and 326 ml l{sup -1} d{sup -1}. Isolate TN1 was the most efficient producer at a rate of 1.85 mol H{sub 2} mol acetate{sup -1} with a light conversion efficiency of 1.07%. The maximum hydrogen production rate for TN1 was determined to be 43 ml l{sup -1} h{sup -1}. Environmentally desirable features of photohydrogen production by TN1 included the absence of pH change in the cultures and no detectable residual CO{sub 2}. (author)

  5. Molecular identification of potential denitrifying bacteria and use of D-optimal mixture experimental design for the optimization of denitrification process.

    Ben Taheur, Fadia; Fdhila, Kais; Elabed, Hamouda; Bouguerra, Amel; Kouidhi, Bochra; Bakhrouf, Amina; Chaieb, Kamel

    2016-04-01

    Three bacterial strains (TE1, TD3 and FB2) were isolated from date palm (degla), pistachio and barley. The presence of nitrate reductase (narG) and nitrite reductase (nirS and nirK) genes in the selected strains was detected by PCR technique. Molecular identification based on 16S rDNA sequencing method was applied to identify positive strains. In addition, the D-optimal mixture experimental design was used to optimize the optimal formulation of probiotic bacteria for denitrification process. Strains harboring denitrification genes were identified as: TE1, Agrococcus sp LN828197; TD3, Cronobacter sakazakii LN828198 and FB2, Pedicoccus pentosaceus LN828199. PCR results revealed that all strains carried the nirS gene. However only C. sakazakii LN828198 and Agrococcus sp LN828197 harbored the nirK and the narG genes respectively. Moreover, the studied bacteria were able to form biofilm on abiotic surfaces with different degree. Process optimization showed that the most significant reduction of nitrate was 100% with 14.98% of COD consumption and 5.57 mg/l nitrite accumulation. Meanwhile, the response values were optimized and showed that the most optimal combination was 78.79% of C. sakazakii LN828198 (curve value), 21.21% of P. pentosaceus LN828199 (curve value) and absence (0%) of Agrococcus sp LN828197 (curve value). PMID:26893037

  6. Effect of brine marination on survival and growth of spoilage and pathogenic bacteria during processing and subsequent storage of ready-to-eat shrimp (Pandalus borealis)

    Mejlholm, Ole; Devitt, Tina D.; Dalgaard, Paw

    2012-01-01

    The effect of brine marination at chill temperatures on survival and growth of spoilage and pathogenic bacteria during processing and subsequent storage of ready-to-eat cold water shrimp was studied. Survival and growth of Lactobacillus sakei, Listeria monocytogenes, Salmonella, Staphylococcus...... aureus and Vibrio parahaemolyticus were examined. The effect of brine composition and pH was determined in 12 screening experiments without addition of shrimp. Sixteen challenge tests with shrimp were then carried out to examine the effect of brine composition and storage temperature on survival and...... growth during processing and subsequent storage of brined and drained shrimp in modified atmosphere packaging (MAP). Different brines with (i) acetic and lactic acids (AL) or (ii) benzoic, citric and sorbic acids (BCS) were studied. V. parahaemolyticus was inactivated in brine AL without shrimp whereas...

  7. Spontaneous tumour lysis syndrome in a case of multiple myeloma – A rare occurrence

    Kavitha Saravu

    2013-03-01

    Full Text Available We describe a case of a 40-year-old male patient who was found to have multiple myeloma with spontaneous tumour lysis syndrome (TLS, following a compression fracture of the L–2 vertebrae. Multiple myeloma was confirmed by bone marrow analysis and the M–band on serum protein electrophoresis. Hyperuricaemia (26.2 mg/dL, hyperkalaemia (> 7.0 mEq/L, hyperphosphatemia (16.2 mg of phosphorus/dL, normocalcemia and acute kidney injury, prior to anticancer treatment suggested spontaneous TLS. Inciting events for tumour lysis, such as chemotherapy, dehydration and exposure to steroids were absent. Patient received hydration, hypourecemic drugs and haemodialysis. This case report highlights the rare presentation of multiple myeloma with spontaneous TLS.

  8. Mass entrapment and lysis of Mesodinium rubrum cells in mucus threads observed in cultures with Dinophysis

    Ojamäe, Karin; Hansen, Per Juel; Lips, Inga

    2016-01-01

    The entrapment and death of the ciliate Mesodinium rubrum in the mucus threads in cultures with Dinophysis is described and quantified. Feeding experiments with different concentrations and predator–prey ratios of Dinophysis acuta, Dinophysis acuminata and M. rubrum to study the motility loss and...... aggregate formation of the ciliates and the feeding behaviour of Dinophysis were carried out. In cultures of either Dinophysis species, the ciliates became entrapped in the mucus, which led to the formation of immobile aggregates of M. rubrum and subsequent cell lysis. The proportion of entrapped ciliates...... was influenced by the concentration of Dinophysis and the ratio of predator and prey in the cultures. At high cell concentrations of prey (136 cells mL−1) and predator (100 cells mL−1), a maximum of 17% of M. rubrum cells became immobile and went through cell lysis. Ciliates were observed trapped in...

  9. Characterization of cell lysis in Pseudomonas putida induced upon expression of heterologous killing genes

    Ronchel, M.C.; Molina, L.; Witte, A.; Lutbiz, W.; Molin, Søren; Ramos, J.L.; Rodriguez, Cayo Juan Ramos

    1998-01-01

    Active biological containment systems are based on the controlled expression of killing genes. These systems are of interest for the Pseudomonadaceae because of the potential applications of these microbes as bioremediation agents and biopesticides, The physiological effects that lead to cell death...... upon the induction of expression of two different heterologous killing genes in nonpathogenic Pseudomonas putida KT2440 derivatives have been analyzed, P. putida CMC4 and CMC12 carry in their chromosomes a fusion of the PAl-04/03 promoter to the Escherichia coli gef gene and the phi X174 lysis gene E......, respectively. Expression of the killing genes is controlled by the LacI protein, whose expression is initiated from the XylS-dependent Pm promoter. Under induced conditions, killing of P. putida CMC12 cells mediated by phi X174 lysis protein E was faster than that observed for P. putida CMC4, for which the Gef...

  10. Antibacterial effects of mixtures of extracts of usnea, thyme and angelica obtained using different technological processes against certain types of bacteria of importance in veterinary medicine

    Mišić Dušan

    2010-01-01

    Full Text Available Antibacterial effects of plant extracts were examined using mixtures of extracts obtained using different technological processes: usnea extract was obtained using the process of supercritical extraction (NKE, angelica extract was obtained through supercritical extraction processes (NKE and ultrasound extraction using ethanol (UZ, and thyme extract was obtained using the process of hydrodistillation (HD. Mixtures of the listed extracts were examined in various ratios: U (NKE and T (HD in a ratio of 1:1, U (NKE and T (HD in a ratio of 7:3, U (NKE, T (HD and A (NKE in a ratio of 2:2:1, and U (NKE, T (HD and A (UZ in a ratio of 2:2:1. The investigations covered 15 strains of bacteria of the genus Staphylococcus, Streptococcus and Enterococus, including the strains MRSA, VRE as well as reference strains of S. pyogenes ATCC 19615, S. agalactiae ATCC 27959 and S. aureus ATCC 11632. The antibacterial action of mixes of plant extracts was examined using the microdilution method in bouillon, and the examined mix concentrations were from 1.25 g/mL to 1280 g/mL. The strongest antibacterial effect was exhibited by mixes of usnea (NKE and thyme (HD in ratios of 1:1 and 7:3 with obtained MIC values from 5 g/mL to 160 g/mL, but the MIC value of the listed mixtures for the biggest number of strains amounted to 40 g/mL. A somewhat weaker effect was exhibited by the other examined extract mixtures with obtained MIC values of 10 g/mL to 320 g/mL. Based on the obtained MIC values and the results of previous investigations, it can be concluded that the examined mixtures of plant extracts exhibited a very strong antibacterial effect on the examined bacteria strains. .

  11. Arthroscopic lysis and lavage in patients with temporomandibular anterior disc displacement without reduction

    Machoň, V.; Šedý, Jiří; Klíma, K.; Hirjak, D.; Foltán, R.

    2012-01-01

    Roč. 41, č. 1 (2012), s. 109-113. ISSN 0901-5027 R&D Projects: GA MŠk(CZ) LC554; GA ČR GAP304/10/0320 Grant ostatní: GA MŠk(CZ) 1M0538 Institutional research plan: CEZ:AV0Z50390703 Keywords : temporomandibular joint * arthroscopic lysis * arthroscopic lavage Subject RIV: FJ - Surgery incl. Transplants Impact factor: 1.521, year: 2012

  12. Detecting cell lysis using viscosity monitoring in E. coli fermentation to prevent product loss

    Newton, J. M.; Schofield, D.; Vlahopoulou, J.; Zhou, Y.

    2016-01-01

    Monitoring the physical or chemical properties of cell broths to infer cell status is often challenging due to the complex nature of the broth. Key factors indicative of cell status include cell density, cell viability, product leakage and DNA release to the fermentation broth. The rapid and accurate prediction of cell status for hosts with intracellular protein products can minimise product loss due to leakage at the onset of cell lysis in fermentation. This paper reports the rheological exa...

  13. An improved single-step lysis protocol to measure luciferase bioluminescence in Plasmodium falciparum

    Hasenkamp Sandra; Wong Eleanor H; Horrocks Paul

    2012-01-01

    Abstract This report describes the optimization and evaluation of a simple single-step lysis protocol to measure luciferase bioluminescence from genetically modified Plasmodium falciparum. This protocol utilizes a modified commercial buffer to improve speed of assay and consistency in the bioluminescence signal measured by reducing the manipulation steps required to release the cytoplasmic fraction. The utility of this improved assay protocol is demonstrated in typical assays that explore abs...

  14. Normal human serum (HS) prevents oxidant-induced lysis of cultured endothelial cells (ECs)

    Most studies demonstrating oxidant lysis of cultured ECs are performed in serum-free media or media containing low concentrations of bovine serum. The authors found that HS protects human and bovine ECs from lysis caused by reagent H2O2 or glucose/glucose oxidase (GO)-generated H2O2. EC injury was assessed by 51Cr release, cell detachment, or trypan blue dye exclusion. Protective HS activity was dose-dependent with concentrations greater than or equal to 25% preventing lethal injury. Cytotoxicity at 24 hrs, induced by 20 mU/ml GO, was 90.1 +/- 5.2% without HS vs 1.7 +/- 4.6% with 25% HS present (20 exp). Similar protection was observed with heparinized plasma. Of note, comparable concentrations of bovine serum were devoid of protective activity. Addition of fatty acid-free albumin to the media was also without protective effect. Preliminary characterization showed HS activity was stable to 600C for 30 min, non-dialyzable at 25,000 MW cutoff, and retained in delipidated serum. The HS protection was not merely due to scavenging of exogenous H2O2 as A23187-induced EC lysis was also prevented by HS. Protective activity was not reproduced by purified cerruloplasmin or transferrin. In conclusion, unidentified factor(s) present in HS protect cultured ECs from oxidant-induced lysis. Since endothelium is normally exposed to 100% plasma, the authors suggest that in vitro studies of oxidant-mediated injury be performed in the presence of HS. Factor(s) in HS may play an important role in modulating oxidant-induced vascular injury in vivo

  15. N2O emission in short-cut simultaneous nitrification and denitrification process: dynamic emission characteristics and succession of ammonia-oxidizing bacteria.

    Yan, Yingyan; Li, Ping; Wu, Jinhua; Zhu, Nengwu; Wu, Pingxiao; Wang, Xiangde

    2014-01-01

    A sequencing batch airlift reactor was used to investigate the characteristics of nitrous oxide (N2O) emission and the succession of an ammonia-oxidizing bacteria (AOB) community. The bioreactor could successfully switch from the complete simultaneous nitrification and denitrification (SND) process to the short-cut SND process by increasing the influent pH from 7.0-7.3 to 8.0-8.3. The results obtained showed that, compared with the complete SND process, the TN removal rate and SND efficiency were improved in the short-cut SND process by approximately 13 and 11%, respectively, while the amount of N2O emission was nearly three times larger than that in the complete SND process. The N2O emission was closely associated to nitrite accumulation. Analysis of the AOB microbial community showed that nitrifier denitrification by Nitrosomonas-like AOB could be an important pathway for the enhancement of N2O emission in the short-cut SND process. PMID:24960019

  16. Effect of ultrasonic frequency on the mechanism of formic acid sono-lysis

    The kinetics and mechanism of formic acid sono-chemical degradation were studied at ultrasonic frequencies of 20, 200, and 607 kHz under argon atmosphere. Total yield of HCOOH sono-chemical degradation increases approximately 6-8-fold when the frequency increased from 20 to 200 or to 607 kHz. At low ultrasonic frequencies, HCOOH degradation has been attributed to oxidation with OH. radicals from water sono-lysis and to the HCOOH decarboxylation occurring at the cavitation bubble-liquid interface. With high-frequency ultrasound, the sono-chemical reaction is also influenced by HCOOH dehydration. Whatever the ultrasonic frequency, the sono-lysis of HCOOH yielded H2 and CO2 in the gas phase as well as trace, amounts of oxalic acid and formaldehyde in the liquid phase. However, CO and CH4 formations were only detected under high frequency ultrasound. The most striking difference between low frequency and high frequency ultrasound is that the sono-lysis of HCOOH at high ultrasonic frequencies initiates Fischer-Tropsch hydrogenation of carbon monoxide. (authors)

  17. Tumor lysis syndrome as a contributory factor to the development of reversible posterior leukoencephalopathy

    Ozkan, A.; Ozkalemkas, F.; Ali, R.; Ozkocaman, V.; Ozcelik, T.; Altundal, Y.; Tunali, A. [Uludag University School of Medicine, Division of Hematology, Department of Internal Medicine, Uludag University Hospital, Bursa (Turkey); Hakyemez, B. [Uludag University School of Medicine, Department of Radiology, Bursa (Turkey); Taskapilioglu, O. [Uludag University School of Medicine, Department of Neurology, Bursa (Turkey)

    2006-12-15

    Reversible posterior leukoencephalopathy syndrome (RPLS) is a recently described clinical and radiological entity comprising headache, seizures, altered level of consciousness and visual disturbances in association with transient posterior cerebral white-matter abnormalities. We report a young woman with Burkitt's lymphoma who developed RPLS after combined chemotherapy administered during the tumor lysis syndrome. The symptoms in this patient fitted well with those of RPLS; they included abrupt alterations in mental status, seizures, headache, visual changes and characteristic neuroradiological findings. She was given further combination chemotherapy without any neurological complications, at which time she had already recovered from both RPLS and tumor lysis syndrome. Although many etiological factors have been reported in the development of RPLS, the underlying mechanism is not yet well understood. With prompt and appropriate management, RPLS is usually reversible, and chemotherapy can be continued after complete recovery from RPLS. We suggest that tumor lysis syndrome should be considered as a contributory factor to the development of RPLS in patients for whom treatment with combined chemotherapy for hematological malignancies is planned. (orig.)

  18. Various Culture Media Effect on T4 Phage Lysis and Production

    Muhammad Kamran Taj

    2013-11-01

    Full Text Available Studies on bacteriophage growth and its development played a vital role in the history of molecular biology which in turn helped in clarification of many points. Most of the previous studies on bacteriophage development and growth have been performed under optimal conditions for the host cell. While On the other hand these conditions may not be optimal for the T4 bacteriophage. As a matter of fact in nature E. coli faces many unfavorable growth conditions, good example are those conditions prevailing in the human gut in which E.coli manages to survive well. This study characterizes the effects and influences of well-defined physiological conditions on T4 bacteriophage growth and development. In addition to this, T4 bacteriophage interactions with its bacterial host have also been demonstrated.In our present study we observed that the maximum growth and lysis of T4 bacteriophage was on luria-bertani (LB and nutrient media (NM. Moreover the T4 bacteriophage production and lysis was also good in luria-bertani plus glucose (LB+G media but when compared with its production in luria-bertani (LB and nutrient media it was found to be less than these medium. Our study results also showed that in minimal media (MM rate of growth and lysis activity of T4 bacteriophage was lowest as compared to other mentioned medium.

  19. Selective local lysis and sampling of live cells for nucleic acid analysis using a microfluidic probe

    Kashyap, Aditya; Autebert, Julien; Delamarche, Emmanuel; Kaigala, Govind V.

    2016-01-01

    Heterogeneity is inherent to biology, thus it is imperative to realize methods capable of obtaining spatially-resolved genomic and transcriptomic profiles of heterogeneous biological samples. Here, we present a new method for local lysis of live adherent cells for nucleic acid analyses. This method addresses bottlenecks in current approaches, such as dilution of analytes, one-sample-one-test, and incompatibility to adherent cells. We make use of a scanning probe technology - a microfluidic probe - and implement hierarchical hydrodynamic flow confinement (hHFC) to localize multiple biochemicals on a biological substrate in a non-contact, non-destructive manner. hHFC enables rapid recovery of nucleic acids by coupling cell lysis and lysate collection. We locally lysed ~300 cells with chemical systems adapted for DNA or RNA and obtained lysates of ~70 cells/μL for DNA analysis and ~15 cells/μL for mRNA analysis. The lysates were introduced into PCR-based workflows for genomic and transcriptomic analysis. This strategy further enabled selective local lysis of subpopulations in a co-culture of MCF7 and MDA-MB-231 cells, validated by characteristic E-cadherin gene expression in individually extracted cell types. The developed strategy can be applied to study cell-cell, cell-matrix interactions locally, with implications in understanding growth, progression and drug response of a tumor. PMID:27411740

  20. Constraints on mechanisms and rates of anaerobic oxidation of methane by microbial consortia: process-based modeling of ANME-2 archaea and sulfate reducing bacteria interactions

    B. Orcutt

    2008-11-01

    Full Text Available Anaerobic oxidation of methane (AOM is the main process responsible for the removal of methane generated in Earth's marine subsurface environments. However, the biochemical mechanism of AOM remains elusive. By explicitly resolving the observed spatial arrangement of methanotrophic archaea and sulfate reducing bacteria found in consortia mediating AOM, potential intermediates involved in the electron transfer between the methane oxidizing and sulfate reducing partners were investigated via a consortium-scale reaction transport model that integrates the effect of diffusional transport with thermodynamic and kinetic controls on microbial activity. Model simulations were used to assess the impact of poorly constrained microbial characteristics such as minimum energy requirements to sustain metabolism and cell specific rates. The role of environmental conditions such as the influence of methane levels on the feasibility of H2, formate and acetate as intermediate species, and the impact of the abundance of intermediate species on pathway reversal were examined. The results show that higher production rates of intermediates via AOM lead to increased diffusive fluxes from the methane oxidizing archaea to sulfate reducing bacteria, but the build-up of the exchangeable species can cause the energy yield of AOM to drop below that required for ATP production. Comparison to data from laboratory experiments shows that under the experimental conditions of Nauhaus et al. (2007, none of the potential intermediates considered here is able to support metabolic activity matching the measured rates.

  1. Hydrogenotrophic denitrification process efficiency and the number of denitrifying bacteria (MPN) in the sequencing batch biofilm reactor (SBBR) with platinum and carbon anodes.

    Kłodowska, Izabella; Rodziewicz, Joanna; Janczukowicz, Wojciech; Gotkowska-Płachta, Anna; Cydzik-Kwiatkowska, Agnieszka

    2016-04-15

    This work reports on the effect of electric current density and anode material (platinum, carbon) on the concentration of oxidized and mineral forms of nitrogen, on physical parameters (pH, redox potential, electrical conductivity) and the number of denitrifying bacteria in the biofilm (MPN). Experiments were conducted under anaerobic conditions without and with the flow of electric current (with density of 79 mA·m(-2) and 132 mA·m(-2)). Results obtained in the study enabled concluding that increasing density of electric current caused a decreasing concentration of nitrate in the reactor with platinum anode (R1) and carbon anode (R2). Its concentration depended on anode material. The highest hydrogenotrophic denitrification efficiency was achieved in R2 in which the process was aided by inorganic carbon (CO2) that originated from carbon anode oxidation and the electrical conductivity of wastewater increased as a result of the presence of HCO3(-) and CO3(2-) ions. Strong oxidizing properties of the platinum anode (R1) prevented the accumulation of adverse forms of nitrogen, including nitrite and ammonia. The increase in electric current density affected also a lower number of denitrifying bacteria (MPN) in the biofilm in both reactors (R1 and R2). Metal oxides accumulated on the surface of the cathode had a toxic effect upon microorganisms and impaired the production of a hydrogen donor. PMID:26809836

  2. Evolutionary comparison between viral lysis rate and latent period.

    Bonachela, Juan A; Levin, Simon A

    2014-03-21

    Marine viruses shape the structure of the microbial community. They are, thus, a key determinant of the most important biogeochemical cycles in the planet. Therefore, a correct description of the ecological and evolutionary behavior of these viruses is essential to make reliable predictions about their role in marine ecosystems. The infection cycle, for example, is indistinctly modeled in two very different ways. In one representation, the process is described including explicitly a fixed delay between infection and offspring release. In the other, the offspring are released at exponentially distributed times according to a fixed release rate. By considering obvious quantitative differences pointed out in the past, the latter description is widely used as a simplification of the former. However, it is still unclear how the dichotomy "delay versus rate description" affects long-term predictions of host-virus interaction models. Here, we study the ecological and evolutionary implications of using one or the other approaches, applied to marine microbes. To this end, we use mathematical and eco-evolutionary computational analysis. We show that the rate model exhibits improved competitive abilities from both ecological and evolutionary perspectives in steady environments. However, rate-based descriptions can fail to describe properly long-term microbe-virus interactions. Moreover, additional information about trade-offs between life-history traits is needed in order to choose the most reliable representation for oceanic bacteriophage dynamics. This result affects deeply most of the marine ecosystem models that include viruses, especially when used to answer evolutionary questions. PMID:24361326

  3. Purification and functional analysis of the recombinant protein isolated from E. coli by employing three different methods of bacterial lysis

    MARIJA MOJSIN

    2005-07-01

    Full Text Available In this paper, the purification of the human recombinant protein expressed in E. coli using the GSTGene Fusion System, by applying various methods of bacterial lysis: sonication, freeze/thaw and beadbeating, is presented. The study was an attempt to compare the properties of the proteins obtained by the sonication method, recommended by manufacturers but inaccessible for many researchers, with those obtained using two other readily available lysis methods. The data show that all purified proteins were soluble and intact with the highest protein yield being obtained via the freeze/thaw method. The results of functional analysis indicate that the proteins purified using the sonication and freeze/thaw methods of lysis exhibited similar DNA binding affinity, while the protein purified by beadbeating was also functional but with a lower binding affinity. The conclusion of this study is that all three lysis methods could be successfully employed for protein purification.

  4. Interaction of energized bacteria cells with particles of colloidal gold: peculiarities and kinetic model of the process.

    Ulberg, Z R; Karamushka, V I; Vidybida, A K; Sericov, A A; Dukhin, A S; Gruzina, T G; Pechenaya, V I

    1992-03-16

    It is found that the cells of Bacillus cereus B-4368 at energized state can concentrate the colloidal gold particles on their surface. It is shown that the process depends on metabolic reactions proceeding on the plasma membrane. The inhibitory analysis permits to suppose that the metal concentration is due to the functioning of ATP-dependent generator of the transmembrane potential, apparently, of proton ATPase. Kinetic characteristics of the process show the presence of an intermediate state in the formation of biomineral aggregates. A kinetic model of the studied process is suggested which describes the experimental data well. PMID:1532513

  5. Evasion of Complement-Mediated Lysis and Complement C3 Deposition Are Regulated by Francisella tularensis Lipopolysaccharide O Antigen1

    Clay, Corey D.; Soni, Shilpa; Gunn, John S.; Schlesinger, Larry S.

    2008-01-01

    The bacterium Francisella tularensis (Ft) is a potential weapon of bioterrorism when aerosolized. Macrophage infection is necessary for disease progression and efficient phagocytosis by human macrophages requires serum opsonization by complement. Microbial complement activation leads to surface deposition of a highly regulated protein complex resulting in opsonization or membrane lysis. The nature of complement component C3 deposition, i.e., C3b (opsonization and lysis) or C3bi (opsonization ...

  6. A Case of Childhood Vitrectomy Performed for Dense Vitreous Hemorrhage Secondary to Leukemia Therapy and Tumor Lysis Syndrome

    Kudo, Takashi; Suzuki, Yukihiko; Metoki, Tomomi; Nakazawa, Mitsuru

    2015-01-01

    Purpose To report a case of vitrectomy performed in a child with dense massive vitreous hemorrhage due to secondary acute myelogenous leukemia (AML) and tumor lysis syndrome. Case A 4-year-old boy with clear-cell renal cell carcinoma was successfully treated with chemotherapy in 2011. However, in May 2012, he developed secondary AML. Although he was treated with combined chemotherapy and radiation, tumor lysis syndrome occurred with renal and heart failure complications. After an ultrasound e...

  7. A comparison of different lysis buffers to assess allele dropout from single cells for preimplantation genetic diagnosis.

    Thornhill, A R; McGrath, J A; Eady, R A; Braude, P R; Handyside, A H

    2001-06-01

    Single cell polymerase chain reaction (PCR) for preimplantation genetic diagnosis (PGD) requires high efficiency and accuracy. Allele dropout (ADO), the random amplification failure of one of the two parental alleles, remains the most significant problem in PCR-based PGD testing since it can result in serious misdiagnosis for compound heterozygous or autosomal dominant conditions. A number of different strategies (including the use of lysis buffers to break down the cell and make the DNA accessible) have been employed to combat ADO with varying degrees of success, yet there is still no consensus among PGD centres over which lysis buffer should be used (ESHRE PGD Consortium, 1999). To address this issue, PCR amplification of three genes (CFTR, LAMA3 and PKP1) at different chromosomal loci was investigated. Single lymphocytes from individuals heterozygous for mutations within each of the three genes were collected and lysed in either alkaline lysis buffer (ALB) or proteinase K/SDS lysis buffer (PK). PCR amplification efficiencies were comparable between alkaline lysis and proteinase K lysis for PCR products spanning each of the three mutated loci (DeltaF508 in CFTR 90% vs 88%; R650X in LAMA3 82% vs 78%; and Y71X in PKP1 91% vs 87%). While there was no appreciable difference between ADO rates between the two lysis buffers for the LAMA3 PCR product (25% vs 26%), there were significant differences in ADO rates between ALB and PK for the CFTR PCR product (0% vs 23%) and the PKP1 PCR product (8% vs 56%). Based on these results, we are currently using ALB in preference to PK/SDS buffer for the lysis of cells in clinical PGD. PMID:11438956

  8. Oil eating bacteria

    NONE

    2002-07-01

    The article discusses the unusual technology of using oil-eating bacteria to increase oil recovery. The background for the discovery that bacteria injection into the reservoirs may increase the oil recovery is the study of microbial action in breaking down oil pollution. About 20 per cent of the organisms living naturally in the sea can eat oil. But they need water to grow. In the absence of water, the bacteria produce enzymes to make the oil water soluble and allow them to extract nutrients from them. Oil does not vanish upon being eaten, but enzymes from the digestive process act as effective detergents to wash away the oil, which is then easier to recover.

  9. Screening large numbers of recombinant plasmids: modifications and additions to alkaline lysis for greater efficiency

    XU Yibing; N.V. CHANDRASEKHARAN; Daniel L. SIMMONS

    2006-01-01

    Selecting bacteria transformed with recombinant plasmid is a laborious step in gene cloning experiments. This selection process is even more tedious when large numbers of clones need to be screened. We describe here modifications to the ultra fast plasmid preparation method described previously by Law and Crickmore. The modified method is coupled to an efficient PCR step to rapidly determine orientation of the inserts. Compared to traditional methods of analysis requiring growth of overnight cultures, plasmid isolation and restriction enzyme digestion to determine orientation this procedure allows for the analysis and storage of a large number of recombinants within a few hours.

  10. Investigation of non-photochemical processes in photosynthetic bacteria and higher plants using interference of coherent radiation - a novel approach

    Roháček, Karel; Kloz, M.; Bína, David; Batysta, F.; Vácha, František

    Dordrecht : Springer, 2008 - (Allen, J.; Gantt, E.; Golbeck, J.; Osmond, B.), s. 1549-1552 ISBN 978-1-4020-6707-5. [International Congress on Photosynthesis /14./. Glasgow (GB), 22.07.2007-27.07.2007] R&D Projects: GA AV ČR IAA600960716 Institutional research plan: CEZ:AV0Z50510513 Keywords : non-photochemical processes * coherent radiation Subject RIV: BO - Biophysics

  11. Rumen bacteria

    The rumen is the most extensively studied gut community and is characterized by its high population density, wide diversity and complexity of interactions. This complex, mixed microbial culture is comprised of prokaryote organisms including methane-producing archaebacteria, eukaryote organisms, such as ciliate and flagellate protozoa, anaerobic phycomycete fungi and bacteriophage. Bacteria are predominant (up to 1011 viable cells per g comprising 200 species) but a variety of ciliate protozoa occur widely (104-106/g distributed over 25 genera). The anaerobic fungi are also widely distributed (zoospore population densities of 102-104/g distributed over 5 genera). The occurrence of bacteriophage is well documented (107-109 particles/g). This section focuses primarily on the widely used methods for the cultivation and the enumeration of rumen microbes, especially bacteria, which grow under anaerobic conditions. Methods that can be used to measure hydrolytic enzymes (cellulases, xylanases, amylases and proteinases) are also described, along with cell harvesting and fractionation procedures. Brief reference is also made to fungi and protozoa, but detailed explanations for culturing and enumerating these microbes is presented in Chapters 2.4 and 2.5

  12. Constraints on mechanisms and rates of anaerobic oxidation of methane by microbial consortia: process-based modeling of ANME-2 archaea and sulfate reducing bacteria interactions

    B. Orcutt

    2008-05-01

    Full Text Available Anaerobic oxidation of methane (AOM is the main process responsible for the removal of methane generated in Earth's marine subsurface environments. However, the biochemical mechanism of AOM remains elusive. By explicitly resolving the observed spatial arrangement of methanotrophic archaea and sulfate reducing bacteria found in consortia mediating AOM, potential intermediates involved in the electron transfer between the methane oxidizing and sulfate reducing partners were investigated via a consortium-scale reaction transport model that integrates the effect of diffusional transport with thermodynamic and kinetic controls on microbial activity. Model simulations were used to assess the impact of poorly constrained microbial characteristics such as minimum energy requirements to sustain metabolism, substrate affinity and cell specific rates. The role of environmental conditions such as the influence of methane levels on the feasibility of H2, formate and acetate as intermediate species, and the impact of the abundance of intermediate species on pathway reversal was examined. The results show that higher production rates of intermediates via AOM lead to increased diffusive fluxes from the methane oxidizing archaea to sulfate reducing bacteria, but the build-up of the exchangeable species causes the energy yield of AOM to drop below that required for ATP production. Comparison to data from laboratory experiments shows that under the experimental conditions of Nauhaus et al. (2007, neither hydrogen nor formate is exchanged fast enough between the consortia partners to achieve measured rates of metabolic activity, but that acetate exchange might support rates that approach those observed.

  13. Microbial degradation of N-methyl-2-pyrrolidone in surface water and bacteria responsible for the process.

    Růžička, Jan; Fusková, Jana; Křížek, Karel; Měrková, Markéta; Černotová, Alena; Smělík, Michal

    2016-01-01

    Due to widespread utilization in many industrial spheres and agrochemicals, N-methyl-2-pyrrolidone (NMP) is a potential contaminant of different surface water ecosystems. Hence, investigation was made into its aerobic microbial degradability in samples of water from a river, wetland area and spring. The results showed that the compound was degradable in all water types, and that the fastest NMP removal occurred in 4 days in river water, while in the wetland and spring samples the process was relatively slow, requiring several months to complete. Key bacterial degraders were successfully isolated in all cases, and their identification proved that pseudomonads played a major role in NMP degradation in river water, while the genera Rhodococcus and Patulibacter fulfilled a similar task in the wetland sample. Regarding spring water, degrading members of the Mesorhizobium and Rhizobium genera were found. PMID:26877048

  14. Leukocyte Lysis and Cytokine Induction by the Human Sexually Transmitted Parasite Trichomonas vaginalis

    Mercer, Frances; Diala, Fitz Gerald I.; Chen, Yi-Pei; Molgora, Brenda M.; Ng, Shek Hang; Johnson, Patricia J.

    2016-01-01

    Trichomonas vaginalis (Tv) is an extracellular protozoan parasite that causes the most common non-viral sexually transmitted infection: trichomoniasis. While acute symptoms in women may include vaginitis, infections are often asymptomatic, but can persist and are associated with medical complications including increased HIV susceptibility, infertility, pre-term labor, and higher incidence of cervical cancer. Heightened inflammation resulting from Tv infection could account for these complications. Effective cellular immune responses to Tv have not been characterized, and re-infection is common, suggesting a dysfunctional adaptive immune response. Using primary human leukocyte components, we have established an in vitro co-culture system to assess the interaction between Tv and the cells of the human immune system. We determined that in vitro, Tv is able to lyse T-cells and B-cells, showing a preference for B-cells. We also found that Tv lysis of lymphocytes was mediated by contact-dependent and soluble factors. Tv lysis of monocytes is far less efficient, and almost entirely contact-dependent. Interestingly, a common symbiont of Tv, Mycoplasma hominis, did not affect cytolytic activity of the parasite, but had a major impact on cytokine responses. M. hominis enabled more diverse inflammatory cytokine secretion in response to Tv and, of the cytokines tested, Tv strains cleared of M. hominis induced only IL-8 secretion from monocytes. The quality of the adaptive immune response to Tv is therefore likely influenced by Tv symbionts, commensals, and concomitant infections, and may be further complicated by direct parasite lysis of effector immune cells. PMID:27529696

  15. The lysis cassette of DLP12 defective prophage is regulated by RpoE.

    Rueggeberg, Karl-Gustav; Toba, Faustino A; Bird, Jeremy G; Franck, Nathan; Thompson, Mitchell G; Hay, Anthony G

    2015-08-01

    Expression of the lysis cassette (essD, ybcT, rzpD/rzoD) from the defective lambdoid prophage at the 12th minute of Escherichia coli's genome (DLP12) is required in some strains for proper curli expression and biofilm formation. Regulating production of the lytic enzymes encoded by these genes is critical for maintaining cell wall integrity. In lambdoid phages, late-gene regulation is mediated by the vegetative sigma factor RpoD and the lambda antiterminator Qλ. We previously demonstrated that DLP12 contains a Q-like protein (QDLP12) that positively regulates transcription of the lysis cassette, but the sigma factor responsible for this transcription initiation remained to be elucidated. In silico analysis of essDp revealed the presence of a putative - 35 and - 10 sigma site recognized by the extracytoplasmic stress response sigma factor, RpoE. In this work, we report that RpoE overexpression promoted transcription from essDp in vivo, and in vitro using purified RNAP. We demonstrate that the - 35 region is important for RpoE binding in vitro and that this region is also important for QDLP12-mediated transcription of essDp in vivo. A bacterial two-hybrid assay indicated that QDLP12 and RpoE physically interact in vivo, consistent with what is seen for Qλ and RpoD. We propose that RpoE regulates transcription of the DLP12 lysis genes through interaction with QDLP12 and that proper expression is dependent on an intact - 35 sigma region in essDp. This work provides evidence that the unique Q-dependent regulatory mechanism of lambdoid phages has been co-opted by E. coli harbouring defective DLP12 and has been integrated into the tightly controlled RpoE regulon. PMID:25998262

  16. Lysis of tubercle bacilli in fresh and stored sputum specimens: implications for diagnosing tuberculosis in stored and paucibacillary specimens by PCR

    Chakravorty Soumitesh

    2007-09-01

    Full Text Available Abstract Background Nucleic acid amplification techniques are being used increasingly in diagnosing tuberculosis. In developing countries clinical samples are often stored for subsequent analysis since molecular tests are conducted at only a limited number of laboratories. This study was conducted to assess the speed at which mycobacteria undergo autolysis and free DNA is detected in the supernatant during low-temperature storage. Results Eighty-seven smear positive sputa from tuberculosis patients were analysed immediately and after storage at -20°C. Timelines of 1 and 2 months were selected to assess the maximum extent of DNA loss that occurred during storage. All samples remained PCR- and smear-positive at 1 month and only 1 sample turned negative after 2 months. Bacterial lysis in the specimens was demonstrated by PCR analysis of supernatant fractions; 53% of the freshly analysed samples contained mycobacterial DNA in supernatants. PCR positivity increased significantly during storage (to 69% and 77% after 1 and 2 months of storage, respectively, P Conclusion We conclude that (i freshly isolated sputum contains both intact and lysed mycobacteria, (ii lysis increased during storage and (iii supernatant fractions routinely discarded during sample processing contain mycobacterial DNA. We propose that supernatant is a valuable sample for PCR for both fresh and stored specimens, particularly those with a low bacterial load in addition to conventional sediment.

  17. Sorafenib induced tumor lysis syndrome in an advanced hepatocellular carcinoma patient

    Wu-Shiung Huang; Chang-Hsu Yang

    2009-01-01

    A 55-year-old male patient with hepatitis B-related liver cirrhosis was found to have advanced hepatocellular carcinoma. His AFP was initially 9828 mg/L and rapidly dropped to 5597 mg/L in ten days after oral sorafenib treatment. However, he developed acute renal failure, hyperkalemia, and hyperuricemia 30 d after receiving the sorafenib treatment. Tumor lysis syndrome was suspected and intensive hemodialysis was performed. Despite intensive hemodialysis and other supportive therapy, he developed multiple organ failure (liver, renal, and respiratory failure) and metabolic acidosis. The patient expired 13 d after admission.

  18. Primary structure and functional analysis of the lysis genes of Lactobacillus gasseri bacteriophage phi adh.

    Henrich, B; Binishofer, B; Bläsi, U

    1995-01-01

    The lysis genes of the Lactobacillus gasseri bacteriophage phi adh were isolated by complementation of a lambda Sam mutation in Escherichia coli. Nucleotide sequencing of a 1,735-bp DNA fragment revealed two adjacent coding regions of 342 bp (hol) and 951 bp (lys) in the same reading frame which appear to belong to a common transcriptional unit. Proteins corresponding to the predicted gene products, holin (12.9 kDa) and lysin (34.7 kDa), were identified by in vitro and in vivo expression of t...

  19. WEB-based GEne SeT AnaLysis Toolkit (WebGestalt): update 2013

    Wang, Jing; Duncan, Dexter; Shi, Zhiao; Zhang, Bing

    2013-01-01

    Functional enrichment analysis is an essential task for the interpretation of gene lists derived from large-scale genetic, transcriptomic and proteomic studies. WebGestalt (WEB-based GEne SeT AnaLysis Toolkit) has become one of the popular software tools in this field since its publication in 2005. For the last 7 years, WebGestalt data holdings have grown substantially to satisfy the requirements of users from different research areas. The current version of WebGestalt supports 8 organisms an...

  20. Exploring the use of natural antimicrobial agents and pulsed electric fields to control spoilage bacteria during a beer production process.

    Galvagno, M A; Gil, G R; Iannone, L J; Cerrutti, P

    2007-01-01

    Different natural antimicrobials affected viability of bacterial contaminants isolated at critical steps during a beer production process. In the presence of 1 mg/ml chitosan and 0.3 mg/ml hops, the viability of Escherichia coli in an all malt barley extract wort could be reduced to 0.7 and 0.1% respectively after 2 hour- incubation at 4 degrees C. The addition of 0.0002 mg/ml nisin, 0.1 mg/ml chitosan or 0.3 mg/ml hops, selectively inhibited growth of Pediococcus sp. in more than 10,000 times with respect to brewing yeast in a mixed culture. In the presence of 0.1 mg ml chitosan in beer, no viable cells of the thermoresistant strain Bacillus megaterium were detected. Nisin, chitosan and hops increased microbiological stability during storage of a local commercial beer inoculated with Lactobacillus plantarum or Pediococcus sp. isolated from wort. Pulsed Electric Field (PEF) (8 kV/cm, 3 pulses) application enhanced antibacterial activity of nisin and hops but not that of chitosan. The results herein obtained suggest that the use of these antimicrobial compounds in isolation or in combination with PEF would be effective to control bacterial contamination during beer production and storage. PMID:17987854

  1. Phages of lactic acid bacteria: The role of genetics in understanding phage-host interactions and their co-evolutionary processes

    Mahony, Jennifer, E-mail: j.mahony@ucc.ie [Department of Microbiology, University College Cork, Western Road, Cork (Ireland); Ainsworth, Stuart; Stockdale, Stephen [Department of Microbiology, University College Cork, Western Road, Cork (Ireland); Sinderen, Douwe van, E-mail: d.vansinderen@ucc.ie [Department of Microbiology, University College Cork, Western Road, Cork (Ireland); Alimentary Pharmabiotic Centre, Biosciences Institute, University College Cork, Western Road, Cork (Ireland)

    2012-12-20

    Dairy fermentations are among the oldest food processing applications, aimed at preservation and shelf-life extension through the use of lactic acid bacteria (LAB) starter cultures, in particular strains of Lactococcus lactis, Streptococcus thermophilus, Lactobacillus spp. and Leuconostoc spp. Traditionally this was performed by continuous passaging of undefined cultures from a finished fermentation to initiate the next fermentation. More recently, consumer demands on consistent and desired flavours and textures of dairy products have led to a more defined approach to such processes. Dairy (starter) companies have responded to the need to define the nature and complexity of the starter culture mixes, and dairy fermentations are now frequently based on defined starter cultures of low complexity, where each starter component imparts specific technological properties that are desirable to the product. Both mixed and defined starter culture approaches create the perfect environment for the proliferation of (bacterio)phages capable of infecting these LAB. The repeated use of the same starter cultures in a single plant, coupled to the drive towards higher and consistent production levels, increases the risk and negative impact of phage infection. In this review we will discuss recent advances in tracking the adaptation of phages to the dairy industry, the advances in understanding LAB phage-host interactions, including evolutionary and genomic aspects.

  2. Phages of lactic acid bacteria: the role of genetics in understanding phage-host interactions and their co-evolutionary processes.

    Mahony, Jennifer; Ainsworth, Stuart; Stockdale, Stephen; van Sinderen, Douwe

    2012-12-20

    Dairy fermentations are among the oldest food processing applications, aimed at preservation and shelf-life extension through the use of lactic acid bacteria (LAB) starter cultures, in particular strains of Lactococcus lactis, Streptococcus thermophilus, Lactobacillus spp. and Leuconostoc spp. Traditionally this was performed by continuous passaging of undefined cultures from a finished fermentation to initiate the next fermentation. More recently, consumer demands on consistent and desired flavours and textures of dairy products have led to a more defined approach to such processes. Dairy (starter) companies have responded to the need to define the nature and complexity of the starter culture mixes, and dairy fermentations are now frequently based on defined starter cultures of low complexity, where each starter component imparts specific technological properties that are desirable to the product. Both mixed and defined starter culture approaches create the perfect environment for the proliferation of (bacterio)phages capable of infecting these LAB. The repeated use of the same starter cultures in a single plant, coupled to the drive towards higher and consistent production levels, increases the risk and negative impact of phage infection. In this review we will discuss recent advances in tracking the adaptation of phages to the dairy industry, the advances in understanding LAB phage-host interactions, including evolutionary and genomic aspects. PMID:23089252

  3. Phages of lactic acid bacteria: The role of genetics in understanding phage-host interactions and their co-evolutionary processes

    Dairy fermentations are among the oldest food processing applications, aimed at preservation and shelf-life extension through the use of lactic acid bacteria (LAB) starter cultures, in particular strains of Lactococcus lactis, Streptococcus thermophilus, Lactobacillus spp. and Leuconostoc spp. Traditionally this was performed by continuous passaging of undefined cultures from a finished fermentation to initiate the next fermentation. More recently, consumer demands on consistent and desired flavours and textures of dairy products have led to a more defined approach to such processes. Dairy (starter) companies have responded to the need to define the nature and complexity of the starter culture mixes, and dairy fermentations are now frequently based on defined starter cultures of low complexity, where each starter component imparts specific technological properties that are desirable to the product. Both mixed and defined starter culture approaches create the perfect environment for the proliferation of (bacterio)phages capable of infecting these LAB. The repeated use of the same starter cultures in a single plant, coupled to the drive towards higher and consistent production levels, increases the risk and negative impact of phage infection. In this review we will discuss recent advances in tracking the adaptation of phages to the dairy industry, the advances in understanding LAB phage-host interactions, including evolutionary and genomic aspects.

  4. Bacteriophage Infection of Model Metal Reducing Bacteria

    Weber, K. A.; Bender, K. S.; Gandhi, K.; Coates, J. D.

    2008-12-01

    Microbially-mediated metal reduction plays a significant role controlling contaminant mobility in aqueous, soil, and sedimentary environments. From among environmentally relevant microorganisms mediating metal reduction, Geobacter spp. have been identified as predominant metal-reducing bacteria under acetate- oxidizing conditions. Due to the significance of these bacteria in environmental systems, it is necessary to understand factors influencing their metabolic physiology. Examination of the annotated finished genome sequence of G. sulfurreducens PCA, G. uraniumreducens Rf4, G. metallireduceans GS-15 as well as a draft genome sequence of Geobacter sp. FRC-32 have identified gene sequences of putative bacteriophage origin. Presence of these sequences indicates that these bacteria are susceptible to phage infection. Polymerase chain reaction (PCR) primer sets designed tested for the presence of 12 of 25 annotated phage-like sequences in G. sulfurreducens PCA and 9 of 17 phage-like sequences in FRC- 32. The following genes were successfully amplified in G. sulfurreducens PCA: prophage type transcription regulator, phage-induced endonuclease, phage tail sheath, 2 phage tail proteins, phage protein D, phage base plate protein, phage-related DNA polymerase, integrase, phage transcriptional regulator, and Cro-like transcription regulator. Nine of the following sequences were present in FRC-32: 4 separate phage- related proteins, phage-related tail component, viron core protein, phage Mu protein, phage base plate, and phage tail sheath. In addition to the bioinformatics evidence, incubation of G. sulfurreducens PCA with 1 μg mL-1 mytomycin C (mutagen stimulating prophage induction) during mid-log phase resulted in significant cell lysis relative to cultures that remained unamended. Cell lysis was concurrent with an increase in viral like particles enumerated using epifluorescent microscopy. In addition, samples collected following this lytic event (~44hours) were

  5. Capacity of tumor necrosis factor to augment lymphocyte-mediated tumor cell lysis of malignant mesothelioma

    Recombinant human tumor necrosis factor (rHuTNF) was evaluated both for direct anti-tumor action against human malignant mesothelioma and for its capacity to augment the generation and lytic phases of lymphocyte-mediated cytotoxicity against this tumor. rHuTNF was directly toxic by MTT assay to one of two mesothelioma cell lines evaluated, but had no effect on susceptibility to subsequent lymphocyte-mediated lysis of either line. TNF alone was incapable of generating anti-mesothelioma lymphokine-activated killer cell (LAK) activity. Furthermore, it did not augment the degree or LAK activity produced by submaximal interleukin-2 (IL-2) concentrations nor did it augment lysis of mesothelioma cells by natural killer (NK) or LAK effector cells during the 4-hr 51chromium release cytolytic reaction. The studies also suggest that mesothelioma targets are less responsive to TNF plus submaximal IL-2 concentrations than the standard LAK sensitive target Daudi, raising the possibility that intermediate LAK sensitive tumors such as mesothelioma may require separate and specific evaluation in immunomodulation studies. This in vitro study indicates that use of low-dose rHuTNF and IL-2 is unlikely to be an effective substitute for high-dose IL-2 in generation and maintenance of LAK activity in adoptive immunotherapy for mesothelioma

  6. Revisiting bistability in the lysis/lysogeny circuit of bacteriophage lambda.

    Michael Bednarz

    Full Text Available The lysis/lysogeny switch of bacteriophage lambda serves as a paradigm for binary cell fate decision, long-term maintenance of cellular state and stimulus-triggered switching between states. In the literature, the system is often referred to as "bistable." However, it remains unclear whether this term provides an accurate description or is instead a misnomer. Here we address this question directly. We first quantify transcriptional regulation governing lysogenic maintenance using a single-cell fluorescence reporter. We then use the single-cell data to derive a stochastic theoretical model for the underlying regulatory network. We use the model to predict the steady states of the system and then validate these predictions experimentally. Specifically, a regime of bistability, and the resulting hysteretic behavior, are observed. Beyond the steady states, the theoretical model successfully predicts the kinetics of switching from lysogeny to lysis. Our results show how the physics-inspired concept of bistability can be reliably used to describe cellular phenotype, and how an experimentally-calibrated theoretical model can have accurate predictive power for cell-state switching.

  7. All-in-one nanowire-decorated multifunctional membrane for rapid cell lysis and direct DNA isolation.

    So, Hongyun

    2014-11-24

    This paper describes a handheld device that uses an all-in-one membrane for continuous mechanical cell lysis and rapid DNA isolation without the assistance of power sources, lysis reagents, and routine centrifugation. This nanowire-decorated multifunctional membrane was fabricated to isolate DNA by selective adsorption to silica surface immediately after disruption of nucleus membranes by ultrasharp tips of nanowires for a rapid cell lysis, and it can be directly assembled with commercial syringe filter holders. The membrane was fabricated by photoelectrochemical etching to create microchannel arrays followed by hydrothermal synthesis of nanowires and deposition of silica. The proposed membrane successfully purifies high-quality DNA within 5 min, whereas a commercial purification kit needs more than an hour.

  8. Improved aqueous extraction of microalgal lipid by combined enzymatic and thermal lysis from wet biomass of Nannochloropsis oceanica.

    Chen, Lin; Li, Runzhi; Ren, Xiaoli; Liu, Tianzhong

    2016-08-01

    High moisture content in wet algal biomass hinders effective performance of current lipid extraction methods. An improved aqueous extraction method combing thermal and enzymatic lysis was proposed and performed in algal slurry of Nannochloropsis oceanica (96.0% moisture) in this study. In general, cell-wall of N. oceanica was disrupted via thermal lysis and enzymatic lysis and lipid extraction was performed using aqueous surfactant solution. At the optimal conditions, high extraction efficiencies for both lipid (88.3%) and protein (62.4%) were obtained, which were significantly higher than those of traditional hexane extraction and other methods for wet algal biomass. Furthermore, an excessive extraction of polar lipid was found for wet biomass compared with dry biomass. The advantage of this method is to efficiently extract lipids from high moisture content algal biomass and avoid using organic solvent, indicating immense potential for commercial microalgae-based biofuel production. PMID:27132220

  9. Rapid method for DNA extraction from the honey bee Apis mellifera and the parasitic bee mite Varroa destructor using lysis buffer and proteinase K.

    Issa, M R C; Figueiredo, V L C; De Jong, D; Sakamoto, C H; Simões, Z L P

    2013-01-01

    We developed a rapid method for extraction of DNA from honey bees, Apis mellifera, and from the parasitic bee mite, Varroa destructor. The advantages include fast processing and low toxicity of the substances that are utilized. We used lysis buffer with nonionic detergents to lyse cell walls and proteinase K to digest proteins. We tested whole thorax, thoracic muscle mass, legs, and antennae from individual bees; the mites were processed whole (1 mite/sample). Each thorax was incubated whole, without cutting, because exocuticle color pigment darkened the extraction solution, interfering with PCR results. The procedure was performed with autoclaved equipment and laboratory gloves. For each sample, we used 100 µL lysis buffer (2 mL stock solution of 0.5 M Tris/HCl, pH 8.5, 10 mL stock solution of 2 M KCl, 500 µL solution of 1 M MgCl2, 2 mL NP40, and 27.6 g sucrose, completed to 200 mL with bidistilled water and autoclaved) and 2 µL proteinase K (10 mg/mL in bidistilled water previously autoclaved, as proteinase K cannot be autoclaved). Tissues were incubated in the solutions for 1-2 h in a water bath (62°-68 °C) or overnight at 37 °C. After incubation, the tissues were removed from the extraction solution (lysis buffer + proteinase K) and the solution heated to 92 °C for 10 min, for proteinase K inactivation. Then, the solution with the extracted DNA was stored in a refrigerator (4°-8 °C) or a freezer (-20 °C). This method does not require centrifugation or phenol/chloroform extraction. The reduced number of steps allowed us to sample many individuals/day. Whole mites and bee antennae were the most rapidly processed. All bee tissues gave the same quality DNA. This method, even using a single bee antenna or a single mite, was adequate for extraction and analysis of bee genomic and mitochondrial DNA and mite genomic DNA. PMID:24301746

  10. Lipoprotein sorting in bacteria.

    Okuda, Suguru; Tokuda, Hajime

    2011-01-01

    Bacterial lipoproteins are synthesized as precursors in the cytoplasm and processed into mature forms on the cytoplasmic membrane. A lipid moiety attached to the N terminus anchors these proteins to the membrane surface. Many bacteria are predicted to express more than 100 lipoproteins, which play diverse functions on the cell surface. The Lol system, composed of five proteins, catalyzes the localization of Escherichia coli lipoproteins to the outer membrane. Some lipoproteins play vital roles in the sorting of other lipoproteins, lipopolysaccharides, and β-barrel proteins to the outer membrane. On the basis of results from biochemical, genetic, and structural studies, we discuss the biogenesis of lipoproteins in bacteria, their importance in cellular functions, and the molecular mechanisms underlying efficient sorting of hydrophobic lipoproteins to the outer membrane through the hydrophilic periplasm. PMID:21663440

  11. Overexpressions of Lambda Phage Lysis Genes and Biosynthetic Genes of Poly-β-hydroxybutyrate in Recombinant E.coli

    1999-01-01

    A plasmid (pTU9) containing the lambda (λ) phage lysis genes S(-)RRz and the biosynthetic genes phbCAB of poly-β-hydroxybutyrate (PHB) was constructed and transformed into E.coli JM109. Cultured in Luria-Bertani (LB) medium with 20 g/L glucose, E.coli JM109 (pTU9) could accumulate PHB in cells up to 40% (g PHB per g dry cells). A chelating agent EDTA was applied to induce a complete cell lysis and PHB granules were released. This method has a potential application in PHB separation.

  12. Abundance and diversity of ammonia-oxidizing archaea and bacteria on granular activated carbon and their fates during drinking water purification process.

    Niu, Jia; Kasuga, Ikuro; Kurisu, Futoshi; Furumai, Hiroaki; Shigeeda, Takaaki; Takahashi, Kazuhiko

    2016-01-01

    Ammonia is a precursor to trichloramine, which causes an undesirable chlorinous odor. Granular activated carbon (GAC) filtration is used to biologically oxidize ammonia during drinking water purification; however, little information is available regarding the abundance and diversity of ammonia-oxidizing archaea (AOA) and bacteria (AOB) associated with GAC. In addition, their sources and fates in water purification process remain unknown. In this study, six GAC samples were collected from five full-scale drinking water purification plants in Tokyo during summer and winter, and the abundance and community structure of AOA and AOB associated with GAC were studied in these two seasons. In summer, archaeal and bacterial amoA genes on GACs were present at 3.7 × 10(5)-3.9 × 10(8) gene copies/g-dry and 4.5 × 10(6)-4.2 × 10(8) gene copies/g-dry, respectively. In winter, archaeal amoA genes remained at the same level, while bacterial amoA genes decreased significantly for all GACs. No differences were observed in the community diversity of AOA and AOB from summer to winter. Phylogenetic analysis revealed high AOA diversity in group I.1a and group I.1b in raw water. Terminal-restriction fragment length polymorphism analysis of processed water samples revealed that AOA diversity decreased dramatically to only two OTUs in group I.1a after ozonation, which were identical to those detected on GAC. It suggests that ozonation plays an important role in determining AOA diversity on GAC. Further study on the cell-specific activity of AOA and AOB is necessary to understand their contributions to in situ nitrification performance. PMID:26463999

  13. Back To Bacteria.

    Flannery, Maura C.

    1997-01-01

    Explores new research about bacteria. Discusses bacterial genomes, archaea, unusual environments, evolution, pathogens, bacterial movement, biofilms, bacteria in the body, and a bacterial obsession. Contains 29 references. (JRH)

  14. Viral abundance, production, decay rates and life strategies (lysogeny versus lysis) in Lake Bourget (France).

    Thomas, Rozenn; Berdjeb, Lyria; Sime-Ngando, Télesphore; Jacquet, Stéphan

    2011-03-01

    We have investigated the ecology of viruses in Lake Bourget (France) from January to August 2008. Data were analysed for viral and bacterial abundance and production, viral decay, frequency of lysogenic cells, the contribution of bacteriophages to prokaryotic mortality and their potential influence on nutrient dynamics. Analyses and experiments were conducted on samples from the epilimnion (2 m) and the hypolimnion (50 m), taken at the reference site of the lake. The abundance of virus-like particles (VLP) varied from 3.4 × 10⁷to 8.2 × 10⁷ VLP ml⁻¹; with the highest numbers and virus-to-bacterium ratio (VBR = 69) recorded in winter. Viral production varied from 3.2 × 10⁴ VLP ml⁻¹  h⁻¹ (July) to 2 × 10⁶ VLP ml⁻¹ h⁻¹ (February and April), and production was lower in the hypolimnion. Viral decay rate reached 0.12-0.15 day⁻¹, and this parameter varied greatly with sampling date and methodology (i.e. KCN versus filtration). Using transmission electron microscopy (TEM) analysis, viral lysis was responsible for 0% (January) to 71% (February) of bacterial mortality, while viral lysis varied between 0% (April) and 53% (January) per day when using a modified dilution approach. Calculated from viral production and burst size, the virus-induced bacterial mortality varied between 0% (January) and 68% (August). A weak relationship was found between the two first methods (TEM versus dilution approach). Interestingly, flow cytometry analysis performed on the dilution experiment samples revealed that the viral impact was mostly on high DNA content bacterial cells whereas grazing, varying between 8.3% (June) and 75.4% (April), was reflected in both HDNA and LDNA cells equally. The lysogenic fraction varied between 0% (spring/summer) and 62% (winter) of total bacterial abundance, and increased slightly with increasing amounts of mitomycin C added. High percentages of lysogenic cells were recorded when bacterial abundance and activity were the lowest

  15. Microbial Adhesion to Processing Lines for Fish Fillets and Cooked Shrimp: Influence of Stainless Steel Surface Finish and Presence of Gram-Negative Bacteria on the Attachment of Listeria monocytogenes

    Guðbjörnsdóttir, Birna; Einarsson, Hjörleifur; Thorkelsson, Guðjón

    2005-01-01

    Microflora adhering to surfaces of processing lines in a shrimp factory and a fish processing plant was identified in situ and adhesion of mixed culture of Listeria monocytogenes and Gram-negative bacteria on stainless steel surfaces (untreated, polished and glass beaded) was studied ex situ. The predominant genus attached to the surfaces was Pseudomonas spp. (66 %) in the shrimp factory and Enterobacteriaceae (27 %) in the fish factory. Shrimp juice was used as an enrichment broth during the...

  16. Selection-Driven Gene Loss in Bacteria

    Koskiniemi, Sanna; Sun, Song; Berg, Otto; Andersson, Dan I.

    2012-01-01

    Gene loss by deletion is a common evolutionary process in bacteria, as exemplified by bacteria with small genomes that have evolved from bacteria with larger genomes by reductive processes. The driving force(s) for genome reduction remains unclear, and here we examined the hypothesis that gene loss is selected because carriage of superfluous genes confers a fitness cost to the bacterium. In the bacterium Salmonella enterica, we measured deletion rates at 11 chromosomal positions and the fitne...

  17. A single lysis solution for the analysis of tissue samples by different proteomic technologies

    Gromov, P.; Celis, J.E.; Gromova, I.; Rank, Fritz; Timmermans, Vera Jacqueline Marita; Moreira, José

    2008-01-01

    Cancer, being a major healthcare concern worldwide, is one of the main targets for the application of emerging proteomic technologies and these tools promise to revolutionize the way cancer will be diagnosed and treated in the near future. Today, as a result of the unprecedented advances that have...... number of protocols for preparation of tissue lysates has been published, so far no single recipe is able to provide a "one-size fits all" solubilization procedure that can be used to analyse the same lysate using different proteomics technologies. Here we present evidence showing that cell lysis buffer......-based proteomics (reverse-phase lysate arrays or direct antibody arrays), allowing the direct comparison of qualitative and quantitative data yielded by these technologies when applied to the same samples. The usefulness of the CLB1 solution for gel-based proteomics was further established by 2D PAGE analysis of a...

  18. Entropy Production Rate Changes in Lysogeny/Lysis Switch Regulation of Bacteriophage Lambda

    According to the chemical kinetic model of lysogeny/lysis switch in Escherichia coli (E. coli) infected by bacteriophage λ, the entropy production rates of steady states are calculated. The results show that the lysogenic state has lower entropy production rate than lytic state, which provides an explanation on why the lysogenic state of λ phage is so stable. We also notice that the entropy production rates of both lysogenic state and lytic state are lower than that of saddle-point and bifurcation state, which is consistent with the principle of minimum entropy production for living organism in nonequilibrium stationary state. Subsequently, the relations between CI and Cro degradation rates at two bifurcations and the changes of entropy production rate with CI and Cro degradation are deduced. The theory and method can be used to calculate entropy change in other molecular network. (interdisciplinary physics and related areas of science and technology)

  19. Stabilizing additives added during cell lysis aid in the solubilization of recombinant proteins.

    David J Leibly

    Full Text Available Insoluble recombinant proteins are a major issue for both structural genomics and enzymology research. Greater than 30% of recombinant proteins expressed in Escherichia coli (E. coli appear to be insoluble. The prevailing view is that insolubly expressed proteins cannot be easily solubilized, and are usually sequestered into inclusion bodies. However, we hypothesize that small molecules added during the cell lysis stage can yield soluble protein from insoluble protein previously screened without additives or ligands. We present a novel screening method that utilized 144 additive conditions to increase the solubility of recombinant proteins expressed in E. coli. These selected additives are natural ligands, detergents, salts, buffers, and chemicals that have been shown to increase the stability of proteins in vivo. We present the methods used for this additive solubility screen and detailed results for 41 potential drug target recombinant proteins from infectious organisms. Increased solubility was observed for 80% of the recombinant proteins during the primary and secondary screening of lysis with the additives; that is 33 of 41 target proteins had increased solubility compared with no additive controls. Eleven additives (trehalose, glycine betaine, mannitol, L-Arginine, potassium citrate, CuCl(2, proline, xylitol, NDSB 201, CTAB and K(2PO(4 solubilized more than one of the 41 proteins; these additives can be easily screened to increase protein solubility. Large-scale purifications were attempted for 15 of the proteins using the additives identified and eight (40% were prepared for crystallization trials during the first purification attempt. Thus, this protocol allowed us to recover about a third of seemingly insoluble proteins for crystallography and structure determination. If recombinant proteins are required in smaller quantities or less purity, the final success rate may be even higher.

  20. Population dynamics in biological treatment process. ; Population dynamics of bacteria for biological phosphorus removal. Population dynamics to kankyo joka. ; Datsurin kin gun no population dynamics

    Okada, M. (Hiroshima Univ., Hiroshima (Japan). Faculty of Engineering)

    1992-09-10

    The microbial industry can easily cultivate only the specific microorganism by introducing the closed reaction system and the sterile operation. When the superior bacteria is selected or it is created by the gene manipulation, therefore, it is not so much difficult that it is utilized for production. Since the water treatment is an open reaction system many microorganisms can join, however, it becomes to be important that how the necessary microorganisms, for example, the dephosphorylation bacteria etc. out of them are let fixed in the reaction system, and win in a competition with the other microorganisms, and in addition, are let display their functions stably for a long period. In this regard, in this paper, concerning to the issues that whether the dephosphorylation bacteria exists or not, how the behavior of dephosphorylation bacteria in the activated sludge should be clarified, what kind of behavior the dephosphorylation bacteria shows in the dephosphorylation activated sludge and so forth, grasping the population dynamics of microorganism, and furthermore, including the methodology to control it, is outlined. 31 refs., 2 figs., 1 tab.

  1. Hypoxia-inducible miR-210 regulates the susceptibility of tumor cells to lysis by cytotoxic T cells.

    Noman, Muhammad Zaeem; Buart, Stéphanie; Romero, Pedro; Ketari, Sami; Janji, Bassam; Mari, Bernard; Mami-Chouaib, Fathia; Chouaib, Salem

    2012-09-15

    Hypoxia in the tumor microenvironment plays a central role in the evolution of immune escape mechanisms by tumor cells. In this study, we report the definition of miR-210 as a miRNA regulated by hypoxia in lung cancer and melanoma, documenting its involvement in blunting the susceptibility of tumor cells to lysis by antigen-specific cytotoxic T lymphocytes (CTL). miR-210 was induced in hypoxic zones of human tumor tissues. Its attenuation in hypoxic cells significantly restored susceptibility to autologous CTL-mediated lysis, independent of tumor cell recognition and CTL reactivity. A comprehensive approach using transcriptome analysis, argonaute protein immunoprecipitation, and luciferase reporter assay revealed that the genes PTPN1, HOXA1, and TP53I11 were miR-210 target genes regulated in hypoxic cells. In support of their primary importance in mediating the immunosuppressive effects of miR-210, coordinate silencing of PTPN1, HOXA1, and TP53I11 dramatically decreased tumor cell susceptibility to CTL-mediated lysis. Our findings show how miR-210 induction links hypoxia to immune escape from CTL-mediated lysis, by providing a mechanistic understanding of how this miRNA mediates immunosuppression in oxygen-deprived regions of tumors where cancer stem-like cells and metastatic cellular behaviors are known to evolve. PMID:22962263

  2. Why bacteria are smaller in the epilimnion than in the hypolimnion? A hypothesis comparing temperate and tropical lakes

    Roberto Bertoni; Cristiana Callieri; J. Salvador Hernandez-Aviles; Miroslav Macek

    2012-01-01

    Bacterial size and morphology are controlled by several factors including predation, viral lysis, UV radiation, and inorganic nutrients. We observed that bacterial biovolume from the hypolimnion of two oligotrophic lakes is larger than that of bacteria living in the layer from surface to 20 m, roughly corresponding to the euphotic/epilimnetic zone. One lake is located in the temperate region at low altitude (Lake Maggiore, Northern Italy) and the other in the tropical region at high altitude ...

  3. Dynamics of Dissolved Organic Matter and its Bioavailability to Heterotrophic Bacteria in the Gulf of Finland, Northern Baltic Sea

    Hoikkala, Laura

    2012-01-01

    Dissolved organic matter (DOM) in surface waters originates from allochthonous and autochthonous sources, the latter of which includes exudation by phytoplankton, viral lysis of planktonic organisms and 'sloppy' feeding by zooplankton. The concentration of DOM in seawater exceeds by one to two orders of magnitude that of particulate organic matter. Thus the DOM pool may be crucial to nutrition of pelagic osmotrophs, such as bacteria and algae, which are capable of exploiting dissolved organic...

  4. Sampling bacteria with a laser

    Schwarzwälder, Kordula; Rutschmann, Peter

    2014-05-01

    Water quality is a topic of high interest and it's getting more and more important due to climate change and the implementation of European Water Framework Directive (WFD). One point of interest here is the inflow of bacteria into a river caused by combined sewer overflows which lead untreated wastewater including bacteria directly into a river. These bacteria remain in the river for a certain time, they settle down and can be remobilised again. In our study we want to investigate these processes of sedimentation and resuspension and use the results for the development of a software module coupled with the software Flow3D. Thereby we should be able to simulate and therefore predict the water quality influenced by combined sewer overflows. Hence we need to get information about the bacteria transport and fate. We need to know about the size of the bacteria or of the bacteria clumps and the size of the particles the bacteria are attached to. The agglomerates lead to different characteristics and velocities of settlement. The timespan during this bacteria can be detected in the bulk phase depends on many factors like the intensity of UV light, turbidity of the water, the temperature of the water, if there are grazers and a lot more. The size, density and composition of the agglomerates is just a part of all these influencing factors, but it is extremely difficult to differ between the other effects if we have no information about the simple sedimentation in default of these basic information. However we have a big problem getting the data. The chaining between bacteria or bacteria and particles is not too strong, so filtering the water to get a sieving curve may destroy these connections. We did some experiments similar to PIV (particle image velocimetry) measurements and evaluated the pictures with a macro written for the software ImageJ. Doing so we were able to get the concentration of bacteria in the water and collect information about the size of the bacteria. We

  5. Bacteria cell properties and grain size impact on bacteria transport and deposition in porous media.

    Bai, Hongjuan; Cochet, Nelly; Pauss, André; Lamy, Edvina

    2016-03-01

    The simultaneous role of bacteria cell properties and porous media grain size on bacteria transport and deposition behavior was investigated in this study. Transport column experiments and numerical HYDRUS-1D simulations of three bacteria with different cell properties (Escherichia coli, Klebsiella oxytoca, and Rhodococcus rhodochrous) were carried out on two sandy media with different grain sizes, under saturated steady state flow conditions. Each bacterium was characterized by cell size and shape, cell motility, electrophoretic mobility, zeta potential, hydrophobicity and potential of interaction with the sand surface. Cell characteristics affected bacteria transport behavior in the fine sand, but similar bacteria breakthroughs and retardation factors observed in the coarse sand, indicated that bacteria transport was more depended on grain size than on bacteria cell properties. Retention decreased with increasing hydrophobicity and increased with increasing electrophoretic mobility of bacteria for both sand. The increasing sand grain size resulted in a decrease of bacteria retention, except for the motile E. coli, indicating that retention of this strain was more dependent on cell motility than on the sand grain size. Bacteria deposition coefficients obtained from numerical simulations of the retention profiles indicated that straining was an important mechanism affecting bacteria deposition of E. coli and Klebsiella sp., in the fine sand, but the attachment had the same importance as straining for R. rhodochrous. The results obtained in the coarse sand did not permit to discriminate the predominant mechanism of bacteria deposition and the relative implication of bacteria cell properties of this process. PMID:26705829

  6. Investigation of the non-photochemical processes in photosynthetic bacteria and higher plants using interference of coherent radiation - a new approach

    Roháček, Karel; Kloz, M.; Bína, David; Batysta, F.; Vácha, František

    2007-01-01

    Roč. 91, 2-3 (2007), s. 301. ISSN 0166-8595. [International Congress of Photosynthesis /14./. 22.07.2007-27.07.2007, Glasgow] Institutional research plan: CEZ:AV0Z50510513 Keywords : photosynthetic bacteria Subject RIV: CE - Biochemistry

  7. Bacteria isolated from amoebae/bacteria consortium

    Tyndall, Richard L.

    1995-01-01

    New protozoan derived microbial consortia and method for their isolation are provided. Consortia and bacteria isolated therefrom are useful for treating wastes such as trichloroethylene and trinitrotoluene. Consortia, bacteria isolated therefrom, and dispersants isolated therefrom are useful for dispersing hydrocarbons such as oil, creosote, wax, and grease.

  8. Potential role of bacteria packaging by protozoa in the persistence and transmission of pathogenic bacteria

    Alix M Denoncourt

    2014-05-01

    Full Text Available Many pathogenic bacteria live in close association with protozoa. These unicellular eukaryotic microorganisms are ubiquitous in various environments. A number of protozoa such as amoebae and ciliates ingest pathogenic bacteria, package them usually in membrane structures, and then release them into the environment. Packaged bacteria are more resistant to various stresses and are more apt to survive than free bacteria. New evidence indicates that protozoa and not bacteria control the packaging process. It is possible that packaging is more common than suspected and may play a major role in the persistence and transmission of pathogenic bacteria. To confirm the role of packaging in the propagation of infections, it is vital that the molecular mechanisms governing the packaging of bacteria by protozoa be identified as well as elements related to the ecology of this process in order to determine whether packaging acts as a Trojan Horse.

  9. Bleach vs. Bacteria

    ... Articles | Inside Life Science Home Page Bleach vs. Bacteria By Sharon Reynolds Posted April 2, 2014 Your ... hypochlorous acid to help kill invading microbes, including bacteria. Researchers funded by the National Institutes of Health ...

  10. A modified alkaline lysis method for the preparation of highly purified plasmid DNA from Escherichia coli.

    Feliciello, I; Chinali, G

    1993-08-01

    We have developed a very efficient and rapid method for the preparation on a small or large scale of highly purified plasmid DNA from Escherichia coli. The procedure consists of five steps: (1) cell lysis by NaOH-SDS, (2) precipitation of cell lysate with 2 M potassium acetate-1 M acetic acid, (3) precipitation of the resulting supernatant with isopropanol, (4) treatment of the precipitate with RNase, and (5) a second isopropanol precipitation. The new procedure yields a plasmid DNA that is more than 90% in the supercoiled form and virtually free from proteins, RNA, and chromosomal DNA. We have thoroughly tested the method in the preparation of several thousand samples of different plasmids from various E. coli strains. We found that it consistently produced samples of plasmid DNA suitable for all routine uses such as restriction analysis, sequencing, and preparation of DNA probes for cloning and hybridization experiments. Moreover, plasmids purified by this procedure could fully replace plasmids purified on CsCl gradients for more demanding tasks such as the in vitro synthesis of RNA probes by phage RNA polymerases, the generation of deletion mutants with exonuclease III, and the transfection of mammalian cells by the calcium phosphate coprecipitation method, as tested on human fibroblasts and on CV-1 cells. PMID:8214582

  11. Chimeric mouse-human IgG1 antibody that can mediate lysis of cancer cells

    A chimeric mouse-human antibody has been created that recognizes an antigen found on the surface of cells from many carcinomas. Immunoglobulin constant (C) domains of the mouse monoclonal antibody L6, C/sub γ2a/ and C/sub kappa/, were substituted by the human C/sub γ1/ and C/sub kappa/ by recombining cDNA modules encoding variable or C domains. The cDNA constructs were transfected into lymphoid cells for antibody production. The chimeric antibody and mouse L6 antibody bound to carcinoma cells with equal affinity and mediated complement-dependent cytolysis. In the presence of human effector cells, the chimeric antibody gave antibody-dependent cellular cytotoxicity at 100 times lower concentration than that needed for the mouse L6 antibody. The assay for lysis was carried out with 51Cr-labeled target calls. The chimeric antibody, but not the mouse L6 antibody, is effective against a melanoma line expressing small amounts of the L6 antigen. The findings point to the usefulness of the chimeric antibody approach for obtaining agents with strong antitumor activity for possible therapeutic use in man

  12. Screening of plants acting against Heterometrus laoticus scorpion venom activity on fibroblast cell lysis.

    Uawonggul, Nunthawun; Chaveerach, Arunrat; Thammasirirak, Sompong; Arkaravichien, Tarinee; Chuachan, Chattong; Daduang, Sakda

    2006-01-16

    The aqueous extracts of 64 plant species, listed as animal- or insect-bite antidotes in old Thai drug recipes were screened for their activity against fibroblast cell lysis after Heterometrus laoticus scorpion venom treatment. The venom was preincubated with plant extract for 30 min and furthered treated to confluent fibroblast cells for 30 min. More than 40% efficiency (test/control) was obtained from cell treatment with venom preincubated with extracts of Andrographis paniculata Nees (Acanthaceae), Barringtonia acutangula (L.) Gaertn. (Lecythidaceae), Calamus sp. (Palmae), Clinacanthus nutans Lindau (Acanthaceae), Euphorbia neriifolia L. (Euphorbiaceae), Ipomoea aquatica Forssk (Convolvulaceae), Mesua ferrea L. (Guttiferae), Passiflora laurifolia L. (Passifloraceae), Plectranthus amboinicus (Lour.) Spreng. (Labiatae), Ricinus communis L. (Euphorbiaceae), Rumex sp. (Polygonaceae) and Sapindus rarak DC. (Sapindaceae), indicating that they had a tendency to be scorpion venom antidotes. However, only Andrographis paniculata and Barringtonia acutangula extracts provided around 50% viable cells from extract treatments without venom preincubation. These two plant extracts are expected to be scorpion venom antidotes with low cytotoxicity. PMID:16169172

  13. Minimal gene regulatory circuits for a lysis-lysogeny choice in the presence of noise.

    Mikkel Avlund

    Full Text Available Gene regulatory networks (GRNs that make reliable decisions should have design features to cope with random fluctuations in the levels or activities of biological molecules. The phage λ GRN makes a lysis-lysogeny decision informed by the number of phages infecting the cell. To analyse the design of decision making GRNs, we generated random in silico GRNs comprised of two or three transcriptional regulators and selected those able to perform a λ-like decision in the presence of noise. Various two-protein networks analogous to the λ CI-Cro GRN worked in noise-less conditions but failed when noise was introduced. Adding a λ CII-like protein significantly improved robustness to noise. CII relieves the CI-like protein of its 'decider' function, allowing CI to be optimized as a decision 'maintainer'. CII's lysogenic decider function was improved by its instability and rapid removal once the decision was taken, preventing its interference with maintenance. A more reliable decision also resulted from simulated co-transcription of the genes for CII and the Cro-like protein, which correlates fluctuations in these opposing decider functions and makes their ratio less noisy. Thus, the λ decision network contains design features for reducing and resisting noise.

  14. Minimal gene regulatory circuits for a lysis-lysogeny choice in the presence of noise.

    Avlund, Mikkel; Krishna, Sandeep; Semsey, Szabolcs; Dodd, Ian B; Sneppen, Kim

    2010-01-01

    Gene regulatory networks (GRNs) that make reliable decisions should have design features to cope with random fluctuations in the levels or activities of biological molecules. The phage λ GRN makes a lysis-lysogeny decision informed by the number of phages infecting the cell. To analyse the design of decision making GRNs, we generated random in silico GRNs comprised of two or three transcriptional regulators and selected those able to perform a λ-like decision in the presence of noise. Various two-protein networks analogous to the λ CI-Cro GRN worked in noise-less conditions but failed when noise was introduced. Adding a λ CII-like protein significantly improved robustness to noise. CII relieves the CI-like protein of its 'decider' function, allowing CI to be optimized as a decision 'maintainer'. CII's lysogenic decider function was improved by its instability and rapid removal once the decision was taken, preventing its interference with maintenance. A more reliable decision also resulted from simulated co-transcription of the genes for CII and the Cro-like protein, which correlates fluctuations in these opposing decider functions and makes their ratio less noisy. Thus, the λ decision network contains design features for reducing and resisting noise. PMID:21188148

  15. Preparation of intact chloroplasts by chemically induced lysis of the green alga Dunaliella marina.

    Kombrink, E; Wöber, G

    1980-07-01

    A method for the isolation in high yield of intact chloroplasts from the unicellular green alga Dunaliella marina (Volvocales) is described. This procedure uses chemically induced lysis of cells with the polycationic macromolecules, DEAE-dextran (M=500,000) or poly-D,L-lysine (M=30,000-70,000). Reaction conditions were optimized with respect to obtaining a high yield of intact chloroplasts, after isopycnic centrifugation in a linear sucrose density gradient, by varying the concentration of polycation and the temperature and pH of incubation. Broken chloroplasts devoid of the stromal marker enzymes fructosebisphosphate phosphatase and ribulosebisphosphate carboxylase, but containing mitochondrial (fumarase) and microbody (catalase) contamination, were banded at a bouyant density of 1.18 g cm(-3). Intact chloroplasts, as indicated by their retention of alkaline fructosebisphosphate phosphatase and ribulosebisphosphate carboxylase, were found in 30% yield (chlorophyll in intact cells, 100%) at an equilibrium density of 1.24 g cm(-3). Contamination by cytoplasmic material (pyruvate kinase), mitochondria, and microbodies was less than 8% each. PMID:24306242

  16. Prolonged clot lysis time increases the risk of a first but not recurrent venous thrombosis.

    Karasu, Alev; Baglin, Trevor P; Luddington, Roger; Baglin, Caroline A; van Hylckama Vlieg, Astrid

    2016-03-01

    The role of the fibrinolytic system in the development of venous thrombosis (VT) is unclear. We studied the risk of first and recurrent VT associated with reduced fibrinolysis, as measured by clot lysis time (CLT). We also studied the relationship between CLT and thrombin generation to determine if any relationship between CLT and VT was affected by thrombin generation. Analyses were performed in the Thrombophilia Hypercoagulability Environmental risk for Venous Thromboembolism Study, a two-centre population-based case-control study, including 579 patients and 338 controls, with patients followed from the event to determine incidence of recurrent VT. Hypofibrinolysis was associated with a 1·8-fold increased risk of a first VT [95% confidence interval (CI) 1·2-2·7]. Adjustment for sex, age, study location and Endogenous Thrombin Potential (ETP) did not change the result. The risk of VT was 2·9-fold increased when the 90th percentiles of prolonged CLT and high ETP were combined, with the highest risk for unprovoked first events (Odds Ratio = 4·2, 95% CI 1·3-13·5). In the follow-up study the Hazard Ratio for a recurrent VT associated with hypofibrinolysis was 1·5 (95% CI 0·9-2·6). A weak dose response effect was observed in relation to prolongation of CLT and recurrent VT. Although hypofibrinolysis constitutes a risk factor for a first VT, an association with recurrence is, at best, weak. PMID:26773756

  17. Ag nanoparticles generated using bio-reduction and -coating cause microbial killing without cell lysis.

    Gade, Aniket; Adams, Joshua; Britt, David W; Shen, Fen-Ann; McLean, Joan E; Jacobson, Astrid; Kim, Young-Cheol; Anderson, Anne J

    2016-04-01

    Cost-effective "green" methods of producing Ag nanoparticles (NPs) are being examined because of the potential of these NPs as antimicrobials. Ag NPs were generated from Ag ions using extracellular metabolites from a soil-borne Pythium species. The NPs were variable in size, but had one dimension less than 50 nm and were biocoated; aggregation and coating changed with acetone precipitation. They had dose-dependent lethal effects on a soil pseudomonad, Pseudomonas chlororaphis O6, and were about 30-fold more effective than Ag(+) ions. A role of reactive oxygen species in cell death was demonstrated by use of fluorescent dyes responsive to superoxide anion and peroxide accumulation. Also mutants of the pseudomonad, defective in enzymes that protect against oxidative stress, were more sensitive than the wild type strain; mutant sensitivity differed between exposure to Ag NPs and Ag(+) ions demonstrating a nano-effect. Imaging of bacterial cells treated with the biocoated Ag NPs revealed no cell lysis, but there were changes in surface properties and cell height. These findings support that biocoating the NPs results in limited Ag release and yet they retained potent antimicrobial activity. PMID:26805711

  18. On-Chip Single-Cell Lysis for Extracting Intracellular Material

    Ikeda, Norifumi; Tanaka, Nobuaki; Yanagida, Yasuko; Hatsuzawa, Takeshi

    2007-09-01

    A newly designed microfluidic chip with a pinched-channel structure and two pairs of electrodes has been developed to enable easier single-cell capture and lysis. The function of the chip was evaluated by introducing zucchini protoplast cells into the channel. In the first experiment, we attempted to break a cell using the through force of a triangular pinched structure via electroosmotic flow generated by outer electrodes. The pinched structure appeared to break the cell without applying the electric field to the cell directly; however, in this case, the breakable size of the cell was limited by the width of the pinched structure. The next attempt was to break cells regardless of their sizes using a pair of inner electrodes located under the pinched structure. The inner electrodes generated a gradient electric field around the captured cell by applying an alternative voltage to the electrodes. Captured cells with a diameter from 40 to 85 μm could be broken using the inner electrodes with a trapezoidal pinched structure, and the cells were successfully broken at 10 Vpp or less at a frequency of 1 MHz.

  19. Bacteria and lignin degradation

    Jing LI; Hongli YUAN; Jinshui YANG

    2009-01-01

    Lignin is both the most abundant aromatic (phenolic) polymer and the second most abundant raw material.It is degraded and modified by bacteria in the natural world,and bacteria seem to play a leading role in decomposing lignin in aquatic ecosystems.Lignin-degrading bacteria approach the polymer by mechanisms such as tunneling,erosion,and cavitation.With the advantages of immense environmental adaptability and biochemical versatility,bacteria deserve to be studied for their ligninolytic potential.

  20. Tumour lysis syndrome: A rare acute presentation of locally advanced testicular cancer – Case report and review of literature

    Marcus Chow

    2016-01-01

    Full Text Available Tumour lysis syndrome (TLS is a potentially fatal complication of malignancy or its treatment. This uncommon syndrome comprises laboratory findings of hyperuricaemia, hypocalcaemia, hyperkalaemia and hyperphosphataemia. A literature search revealed a total of eight patients, with testicular cancer, who had TLS. All these patients had metastatic disease. We present a unique case of a 47-year-old gentleman we saw in clinic, who presented with a rapidly growing right groin mass and acute breathlessness, and discuss the diagnosis and management of TLS. TLS is extremely rare in testicular cancer but necessitates the awareness of urologists. TLS can occur spontaneously in testicular malignancy. Cell lysis in a rapidly proliferating germ cell tumour is a possible mechanism. The prompt identification and institution of management for TLS is crucial to improve clinical outcomes.

  1. Sulfolobus Turreted Icosahedral Virus c92 Protein Responsible for the Formation of Pyramid-Like Cellular Lysis Structures

    Snyder, Jamie C; Brumfield, Susan K; Peng, Nan;

    2011-01-01

    Host cells infected by Sulfolobus turreted icosahedral virus (STIV) have been shown to produce unusual pyramid-like structures on the cell surface. These structures represent a virus-induced lysis mechanism that is present in Archaea and appears to be distinct from the holin/endolysin system...... described for DNA bacteriophages. This study investigated the STIV gene products required for pyramid formation in its host Sulfolobus solfataricus. Overexpression of STIV open reading frame (ORF) c92 in S. solfataricus alone is sufficient to produce the pyramid-like lysis structures in cells. Gene...... disruption of c92 within STIV demonstrates that c92 is an essential protein for virus replication. Immunolocalization of c92 shows that the protein is localized to the cellular membranes forming the pyramid-like structures....

  2. Preparation of mycobacterial DNA from blood culture fluids by simple alkali wash and heat lysis method for PCR detection.

    Kulski, J K; Pryce, T

    1996-01-01

    A sodium iodide-isopropanol (NI) method was compared with an alkali wash and heat lysis (AH) procedure for the preparation and extraction of DNA from BACTEC 13A blood culture fluid samples from AIDS patients for use in a PCR for the detection and identification of mycobacteria. The sensitivity and efficiency of the DNA extraction methods were assessed by a multiplex PCR which detected the members of the genus Mycobacterium and differentiated between M. intracellulare, M. tuberculosis, and M. ...

  3. Celecoxib increases lung cancer cell lysis by lymphokine-activated killer cells via upregulation of ICAM-1

    Schellhorn, Melina; Haustein, Maria; Frank, Marcus; Linnebacher, Michael; Hinz, Burkhard

    2015-01-01

    The antitumorigenic mechanism of the selective cyclooxygenase-2 (COX-2) inhibitor celecoxib is still a matter of debate. Using lung cancer cell lines (A549, H460) and metastatic cells derived from a lung cancer patient, the present study investigates the impact of celecoxib on the expression of intercellular adhesion molecule 1 (ICAM-1) and cancer cell lysis by lymphokine-activated killer (LAK) cells. Celecoxib, but not other structurally related selective COX-2 inhibitors (i.e., etoricoxib, ...

  4. Rendering of mycobacteria safe for molecular diagnostic studies and development of a lysis method for strand displacement amplification and PCR.

    Zwadyk, P.; Down, J. A.; Myers, N; Dey, M. S.

    1994-01-01

    Two criteria must be met before mycobacterial specimens can be tested by DNA amplification methods: (i) the sample must be rendered noninfectious, and (ii) the organisms must be lysed to free the DNA. Previous publications reporting DNA amplification of mycobacteria have concentrated on lysis and amplification procedures and have not addressed the issue of sample safety. We have shown that heating of samples below 100 degrees C may not consistently kill mycobacteria; however, heating at 100 d...

  5. Determining Human Clot Lysis Time (in vitro with Plasminogen/Plasmin from Four Species (Human, Bovine, Goat, and Swine

    Omaira Cañas Bermúdez

    2015-05-01

    Full Text Available Cardiovascular disease is the leading cause of death worldwide, including failures in the plasminogen/plasmin system which is an important factor in poor lysis of blood clots. This article studies the fibrinolytic system in four species of mammals, and it identifies human plasminogen with highest thrombolysis efficiency. It examines plasminogen from four species (human, bovine, goat, and swine and identifies the most efficient one in human clot lysis in vitro. All plasminogens were identically purified by affinity chromatography. Human fibrinogen was purified by fractionation with ethanol. The purification of both plasminogen and fibrinogen was characterized by one-dimensional SDS-PAGE (10%. Human clot formation in vitro and its dissolution by plasminogen/plasmin consisted of determining lysis time from clot formation to its dilution. Purification of proteins showed greater than 95% purity, human plasminogen showed greater ability to lyse clot than animal plasminogen. The article concludes that human plasminogen/plasmin has the greatest catalysis and efficiency, as it dissolves human clot up to three times faster than that of irrational species.

  6. RNA integrity as a quality indicator during the first steps of RNP purifications : A comparison of yeast lysis methods

    Jansen Ralf-Peter

    2004-10-01

    Full Text Available Abstract Background The completion of several genome-sequencing projects has increased our need to assign functions to newly identified genes. The presence of a specific protein domain has been used as the determinant for suggesting a function for these new genes. In the case of proteins that are predicted to interact with mRNA, most RNAs bound by these proteins are still unknown. In yeast, several protocols for the identification of protein-protein interactions in high-throughput analyses have been developed during the last years leading to an increased understanding of cellular proteomics. If any of these protocols or similar approaches shall be used for the identification of mRNA-protein complexes, the integrity of mRNA is a critical factor. Results We compared the effect of different lysis protocols on RNA integrity. We report dramatic differences in RNA stability depending on the method used for yeast cell lysis. Glass bead milling and French Press lead to degraded mRNAs even in the presence of RNase inhibitors. Thus, they are not suitable to purify intact mRNP complexes or to identify specific mRNAs bound to proteins. Conclusion We suggest a novel protocol, grinding deep-frozen cells, for the preparation of protein extracts that contain intact RNAs, as lysis method for the purification of mRNA-protein complexes from yeast cells.

  7. c-Myc regulates expression of NKG2D ligands ULBP1/2/3 in AML and modulates their susceptibility to NK-mediated lysis

    Nanbakhsh, Arash; Pochon, Cécile; Mallavialle, Aude; Amsellem, Sophie; Bourhis, Jean Henri; Chouaib, Salem

    2014-01-01

    AML cells resistant to cytarabine are more susceptible to NK-mediated cell lysis.c-Myc regulates ULBP1/2/3 expression and interferes with NK cell susceptibility in primary cytarabine resistant AML blasts.

  8. Characterization of a thermostable endo-1,3(4)-β-glucanase from Caldicellulosiruptor sp. strain F32 and its application for yeast lysis.

    Meng, Dong-Dong; Wang, Bing; Ma, Xiao-Qing; Ji, Shi-Qi; Lu, Ming; Li, Fu-Li

    2016-06-01

    β-1,3-Glucans, important structural components of cell wall or nutritional components of the endosperm, are extensively found in bacteria, fungi, yeast, algae, and plants. The structural complexity of β-1,3-glucans implies that the enzymatic depolymerization of polysaccharides needs combined activities of distinct enzymes. In this study, Lam16A-GH, the catalytic module of a putative glycoside hydrolase (GH) family 16 laminarinase/lichenase from thermophilic bacterium Caldicellulosiruptor sp. F32, was purified and characterized through heterologous expression in Escherichia coli. Lam16A-GH can hydrolyze both β-1,3-glucan (laminarin) and β-1,3-1,4-glucan (barley β-glucan) revealed by analysis of the products of polysaccharide degradation using thin-layer chromatography (TLC). The time required for the loss of 50 % of its activity is 45 h under the optimal condition of 75 °C and pH 6.5. Oligosaccharides degradation assay indicated that Lam16A-GH can catalyze endo-hydrolysis of the β-1,4 glycosidic linkage adjacent to a 3-O-substituted glucosyl residue in the mixed linked β-glucans, as well as the β-1,3 linkage. The survival rate of Saccharomyces cerevisiae cells depends on the addition of Lam16A-GH, and the cytoplasm protein was released from the apparently deconstructed yeast cells. These results indicate that the bi-functional thermostable Lam16A-GH exhibits unique enzymatic properties and potential for yeast lysis. PMID:26837217

  9. Lysis of pig endothelium by IL-2 activated human natural killer cells is inhibited by swine and human major histocompatibility complex (MHC) class I gene products.

    Itescu, S; Artrip, J H; Kwiatkowski, P A; Wang, S F; Minanov, O P; Morgenthau, A S; Michler, R E

    1997-01-01

    We have previously described a form of xenograft rejection, mediated by natural killer (NK) cells, occurring in pig-to-primate organ transplants beyond the period of antibody-mediated hyperacute rejection. In this study, two distinct NK activation pathways were identified as mechanisms of pig aortic endotheliual cell (PAEC) lysis by human NK cells. Using an antibody-dependent cellular cytotoxicity (ADCC) assay, a progressive increase in human NK lysis of PAEC was observed following incubation with human IgG at increasing serum titer. In the absence of IgG, a second mechanism of PAEC lysis by human NK cells was observed following activation with IL-2. IL-2 activation of human NK cells increased lysis of PAEC by over 3-fold compared with ADCC. These results indicate that IL-2 activation of human NK cells induces significantly higher levels of lytic activity than does conventional ADCC involving IgG and FcRIII. We next investigated the role of MHC class I molecules in the regulation of NK lysis following IL-2 activation. PAEC expression of SLA class I molecules was increased by up to 75% by treatment with human TNFa. Following treatment with TNFa at 1 u/ml, IL-2 activated human NK lysis of PAEC was inhibited at every effector:target (E:T) ratio tested. Maximal effect occurred at an E:T ratio of 10:1, with TNFa inhibiting specific lysis by 59% (p < 0.01). Incubation with an anti-SLA class I Mab, but not IgG isotype control, abrogated the protective effects of TNFa on NK lysis of PAEC, suggesting direct inhibitory effects of SLA class I molecules on human NK function. To investigate whether human MHC class I molecules might have similar effects on human NK lysis of PAEC, further experiments were performed using a soluble peptide derived from the alpha-helical region of HLA-B7. Incubation with the HLA-B7 derived peptide significantly reduced the IL-2 activated NK lytic activity against PAEC in a dose-dependent fashion. Maximal effect occurred at a concentration of 10 mg

  10. Virus-specific HLA-restricted lysis of herpes simplex virus-infected human monocytes and macrophages mediated by cytotoxic T lymphocytes

    Freshly-isolated peripheral blood human monocytes and 5 day in vitro cultured macrophages were infected with herpes simplex virus type 1 (HSV-1), labeled with 51Cr, and used as target cells in a 12-14 hour cell-mediated cytotoxicity assay. Mononuclear leukocytes (MNL) from HSV-1 non-immune individuals, whether unstimulated or stimulated with HSV-1 antigen, did not mediate significant lysis of either target cell. HSV-immune MNL, both freshly-isolated and cultured for 5 days without antigen, demonstrated only low levels of natural killer (NK) cell-mediate lysis. MNL from HSV-immune individuals incubated for 5 days in vitro with HSV-1 antigen mediated significant virus-specific lysis of both target cells. Mean virus-specific lysis of autologous monocytes was 8.5(/+-/2.0)% compared to a three-fold greater virus-specific lysis of autologous macrophages. Greater than 70% of this lytic activity was mediated by Leu-11-negative, T3-positive cytotoxic T lymphocytes (CTL). Allogeneic target cells lacking a common HLA determinant were not significantly lysed while T8-positive CTL mediated infrequent lysis of target cells sharing a common HLA-A and/or HLA-B determinant. T4-positive lymphocytes were demonstrated to be the predominant cell mediating lysis of autologous target cells and allogeneic target cells sharing both HLA-A and/or HLA-B plus HLA-DR determinants with the CTL; the T4-positive cell was the sole CTL mediator of lysis of allogeneic target cells having a common HLA-DR determinant

  11. Antibacterial Activity and Action Mechanism of the Essential Oil from Enteromorpha linza L. against Foodborne Pathogenic Bacteria.

    Patra, Jayanta Kumar; Baek, Kwang-Hyun

    2016-01-01

    Foodborne illness and disease caused by foodborne pathogenic bacteria is continuing to increase day by day and it has become an important topic of concern among various food industries. Many types of synthetic antibacterial agents have been used in food processing and food preservation; however, they are not safe and have resulted in various health-related issues. Therefore, in the present study, essential oil from an edible seaweed, Enteromorpha linza (AEO), was evaluated for its antibacterial activity against foodborne pathogens, along with the mechanism of its antibacterial action. AEO at 25 mg/disc was highly active against Bacillus cereus (12.3-12.7 mm inhibition zone) and Staphylococcus aureus (12.7-13.3 mm inhibition zone). The minimum inhibitory concentration and minimum bactericidal concentration values of AEO ranged from 12.5-25 mg/mL. Further investigation of the mechanism of action of AEO revealed its strong impairing effect on the viability of bacterial cells and membrane permeability, as indicated by a significant increase in leakage of 260 nm absorbing materials and K⁺ ions from the cell membrane and loss of high salt tolerance. Taken together, these data suggest that AEO has the potential for use as an effective antibacterial agent that functions by impairing cell membrane permeability via morphological alternations, resulting in cellular lysis and cell death. PMID:27007365

  12. Antibacterial Activity and Action Mechanism of the Essential Oil from Enteromorpha linza L. against Foodborne Pathogenic Bacteria

    Jayanta Kumar Patra

    2016-03-01

    Full Text Available Foodborne illness and disease caused by foodborne pathogenic bacteria is continuing to increase day by day and it has become an important topic of concern among various food industries. Many types of synthetic antibacterial agents have been used in food processing and food preservation; however, they are not safe and have resulted in various health-related issues. Therefore, in the present study, essential oil from an edible seaweed, Enteromorpha linza (AEO, was evaluated for its antibacterial activity against foodborne pathogens, along with the mechanism of its antibacterial action. AEO at 25 mg/disc was highly active against Bacillus cereus (12.3–12.7 mm inhibition zone and Staphylococcus aureus (12.7–13.3 mm inhibition zone. The minimum inhibitory concentration and minimum bactericidal concentration values of AEO ranged from 12.5–25 mg/mL. Further investigation of the mechanism of action of AEO revealed its strong impairing effect on the viability of bacterial cells and membrane permeability, as indicated by a significant increase in leakage of 260 nm absorbing materials and K+ ions from the cell membrane and loss of high salt tolerance. Taken together, these data suggest that AEO has the potential for use as an effective antibacterial agent that functions by impairing cell membrane permeability via morphological alternations, resulting in cellular lysis and cell death.

  13. Phage lambda CIII: a protease inhibitor regulating the lysis-lysogeny decision.

    Oren Kobiler

    Full Text Available The ATP-dependent protease FtsH (HflB complexed with HflKC participates in post-translational control of the lysis-lysogeny decision of bacteriophage lambda by rapid degradation of lambda CII. Both phage-encoded proteins, the CII transcription activator and the CIII polypeptide, are required for efficient lysogenic response. The conserved CIII is both an inhibitor and substrate of FtsH. Here we show that the protease inhibitor CIII is present as oligomeric amphipathic alpha helical structures and functions as a competitive inhibitor of FtsH by preventing binding of the CII substrate. We identified single alanine substitutions in CIII that abolish its activity. We characterize a dominant negative effect of a CIII mutant. Thus, we suggest that CIII oligomrization is required for its function. Real-time analysis of CII activity demonstrates that the effect of CIII is not seen in the absence of either FtsH or HflKC. When CIII is provided ectopically, CII activity increases linearly as a function of the multiplicity of infection, suggesting that CIII enhances CII stability and the lysogenic response. FtsH function is essential for cellular viability as it regulates the balance in the synthesis of phospholipids and lipopolysaccharides. Genetic experiments confirmed that the CIII bacteriostatic effects are due to inhibition of FtsH. Thus, the early presence of CIII following infection stimulates the lysogenic response, while its degradation at later times ensures the reactivation of FtsH allowing the growth of the established lysogenic cell.

  14. 脐血采分和长期冻存后细菌培养的研究%Study on bacteria contamination during the collection, processing and storage of umbilical cord blood

    张乐玲; 马丽霞; 王素兰; 王新党; 李府; 张乐海; 刘兴莉; 沈柏均

    2012-01-01

    目的 探讨脐血采分储存中细菌污染的种类、途径和规律性以及深低温冻存对细菌活力的影响.方法 在2000年至2007年脐血干细胞采分常规工作中,留取有核细胞分离后血浆-红细胞悬液10ml,分别注入需氧和厌氧细菌培养瓶,用BacT/ALERT 3D-480全自动血液培养系统培养7d,细菌培养阳性者作废弃处理.同时选取细菌阳性的新鲜脐血87份进一步培养24h,获得纯培养后,将革兰阳(阴)性菌鉴定卡放入全自动微生物分析系统读数孵育器,分别进行需氧菌与厌氧菌鉴定.另外,为观察深低温冻存对细菌的影响,取出冻存6~7年的细菌阳性脐血96份,37℃速融后,取有核细胞浓缩物10 ml,用上述方法做二次细菌培养检测.结果 2000年至2007年采集脐血19 062份,细菌培养阳性336份,细菌污染率为1.8%;作细菌鉴定87份,发现兼性生长58份(67%),专性需氧生长38份(43.7%),专性厌氧生长17份(19.5%);革兰阴性菌占68%,革兰阳性菌占32%.细菌种类:大肠埃希菌最常见,占25.3%,其次为中间链球菌占14.9%,紫色色杆菌占9.2%.96份细菌鉴测阳性并移至液氮保存6~7年的脐血标本中,经复检仍有83份(86%)保持细菌活性.结论 2000年至2007年脐血采分过程中细菌污染率为1.8%,污染菌在液氮冻存6~7年后86%细菌仍存活.故在产房采集脐血时应加强无菌措施,在临床使用冻存干细胞时应加强细菌复检.%Objective To evaluate bacteria contamination during collection,processing and storage of cord blood to gain insight into contamination mechanism and direct prevention.Methods Fresh cord blood was separated by hydroxyethyl starch (HES) to harvest nucleated cells.The bacteria contamination was tested by culturing 10 ml plasma-red cells with BacT/ALERT 3D-480 automatic blood culture system.Total 87 positive samples were further identified for bacteria species.Ninety six cord blood nucleated cells

  15. The detrimental influence of bacteria (E. coli, Shigella and Salmonella) on the degradation of organic compounds (and vice versa) in TiO2 photocatalysis and near-neutral photo-Fenton processes under simulated solar light.

    Moncayo-Lasso, Alejandro; Mora-Arismendi, Luis Enrique; Rengifo-Herrera, Julián Andrés; Sanabria, Janeth; Benítez, Norberto; Pulgarin, César

    2012-05-01

    TiO2 photocatalytic and near-neutral photo-Fenton processes were tested under simulated solar light to degrade two models of natural organic matter - resorcinol (R) (which should interact strongly with TiO2 surfaces) and hydroquinone (H) - separately or in the presence of bacteria. Under similar oxidative conditions, inactivation of Escherichia coli, Shigella sonnei and Salmonella typhimurium was carried out in the absence and in the presence of 10 mg L(-1) of R and H. The 100% abatement of R and H by using a TiO2 photocatalytic process in the absence of bacteria was observed in 90 min for R and in 120 min for H, while in the presence of microorganisms abatement was only of 55% and 35% for R and H, respectively. Photo-Fenton reagent at pH 5.0 completely removed R and H in 40 min, whereas in the presence of microorganisms their degradation was of 60% to 80%. On the other hand, 2 h of TiO2 photocatalytic process inactivated S. typhimurium and E. coli cells in three and six orders of magnitude, respectively, while S. sonnei was completely inactivated in 10 min. In the presence of R or H, the bacterial inactivation via TiO2 photocatalysis was significantly decreased. With photo-Fenton reagent at pH 5 all the microorganisms tested were completely inactivated in 40 min of simulated solar light irradiation in the absence of organics. When R and H were present, bacterial photo-Fenton inactivation was less affected. The obtained results suggest that in both TiO2 and iron photo-assisted processes, there is competition between organic substances and bacteria simultaneously present for generated reactive oxygen species (ROS). This competition is most important in heterogeneous systems, mainly when there are strong organic-TiO2 surface interactions, as in the resorcinol case, suggesting that bacteria-TiO2 interactions could play a key role in photocatalytic cell inactivation processes. PMID:22370626

  16. 乳酸菌在干辣椒发酵中的应用%The Appl ication of Lactic Acid Bacteria in Fermentation Process of Dry Red Pepper

    万春秋; 刘德忠

    2015-01-01

    The orthogonal test is conducted by taking dry pepper as the raw material,adding lactic acid bacteria to produce chili paste.The results show that the optimal production conditions are as follows:the salt concentration of 10%,the inoculum size of 1 .0%,the fermentation temperature of 25 ℃ and the fermentation time of 20 days.Then the scale validation is carried out in the factory,the experimental results show that adding lactic acid bacteria not only shortens the fermentation time,but also the color of product is brighter,the aroma is stronger,the freshness is higher and the stability is better.%文章阐述了以干辣椒为原料,添加乳酸菌发酵生产辣椒酱,通过正交试验结果表明:最佳生产条件为食盐浓度10%,接种量1.0%,发酵温度25℃,发酵时间20天。然后在工厂进行了规模化验证,实验表明:添加乳酸菌发酵技术不仅缩短发酵的时间,且其产品的色泽更鲜艳、香味更浓郁、鲜度更高、稳定性更好。

  17. Linking N2O emission from biochar-amended composting process to the abundance of denitrify (nirK and nosZ) bacteria community.

    Li, Shuqing; Song, Lina; Jin, Yaguo; Liu, Shuwei; Shen, Qirong; Zou, Jianwen

    2016-12-01

    Manure composting has been recognized as an important anthropogenic source of nitrous oxide (N2O) contributing to global warming. However, biochar effect on N2O emissions from manure composting is rarely evaluated, especially by linking it to abundance of denitrifying bacteria community. Results of this study indicated that biochar amendment significantly reduced N2O emissions from manure composting, primarily due to suppression of the nirK gene abundance of denitrifying bacteria. Pearson's correlation analysis showed a significant positive correlation between nirK abundance and N2O fluxes, while a negative correlation between nosZ density and N2O fluxes. Simultaneously, a linear correlation between nirK gene abundance minus nosZ gene abundance with N2O fluxes was also observed. In addition, a statistical model for estimating N2O emissions based on the bacterial denitrifying functional genes was developed and verified to adequately fit the observed emissions. Our results highlighted that biochar amendment would be an alternative strategy for mitigating N2O emissions during manure composting, and the information of related functional bacterial communities could be helpful for understanding the mechanism of N2O emissions. PMID:27207069

  18. Effects of Compound Bacteria on Processing Quality of Wild Vegetables%复合发酵菌剂对山野菜加工品质的影响

    黄静; 岳晓敏; 任元元; 康建平

    2013-01-01

      采用自然发酵、复合菌制剂对比发酵山野菜(山露、薇菜),结果表明复合菌制剂发酵比自然发酵总酸、总糖、氨基态氮含量更高。植物乳杆菌和酵母菌两种发酵液体积比为3∶1,发酵时间为40d时,发酵山野菜的口感、风味和色泽三种品味最佳。%  The paper compared natural fermentation of wild vegetables with compound bacteria fermentation.The re-sults showed that the compound bacteria fermentation’s total acid, total sugar, amino nitrogen content were higher than the natural fermentation. The taste, flavor and color of wild vegetables are the best when the volume ratio of Lactobacillus plantarum and yeast 3:1 and fermentation time 40 days.

  19. Use of UV-irradiated bacteriophage T6 to kill extracellular bacteria in tissue culture infectivity assays

    The authors have utilized 'lysis from without' mediated by UV-inactivated bacteriophage T6 to eliminate extracellular bacteria in experiments measuring the internalization, intracellular survival and replication of Yersinia pestis within mouse peritoneal macrophages and of Shigella flexneri within a human intestinal epithelial cell line. The technique described has the following characteristics: (a) bacterial killing is complete within 15 min at 370C, with a >103-fold reduction in colony-forming units (CFU); (b) bacteria within cultured mammalian cells are protected from killing by UV-inactivated T6; (c) the mammalian cells are not observably affected by exposure to UV-inactivated T6. This technique has several advantages over the use of antibiotics to eliminate extracellular bacteria and is potentially widely applicable in studies of the interactions between pathogenic bacteria and host phagocytic cells as well as other target tissues. (Auth.)

  20. Can the development and autolysis of lactic acid bacteria influence the cheese volatile fraction? The case of Grana Padano.

    Lazzi, Camilla; Povolo, Milena; Locci, Francesco; Bernini, Valentina; Neviani, Erasmo; Gatti, Monica

    2016-09-16

    In this study, the relationship between the dynamics of the growth and lysis of lactic acid bacteria in Grana Padano cheese and the formation of the volatile flavor compounds during cheese ripening was investigated. The microbial dynamics of Grana Padano cheeses that were produced in two different dairies were followed during ripening. The total and cultivable lactic microflora, community composition as determined by length heterogeneity-PCR (LH-PCR), and extent of bacterial lysis using an intracellular enzymatic activity assay were compared among cheeses after 2, 6 and 13months of ripening in two dairies. The evolution of whole and lysed microbiota was different between the two dairies. In dairy 2, the number of total cells was higher than that in dairy 1 in all samples, and the number of cells that lysed during ripening was lower. In addition, at the beginning of ripening (2months), the community structure of the cheese from dairy 2 was more complex and was composed of starter lactic acid bacteria (Lactobacillus helveticus and Lactobacillus delbrueckii) and NSLAB, possibly arising from raw milk, including Lactobacillus rhamnosus/Lactobacillus casei and Pediococcus acidilactici. On the other hand, the cheese from dairy 1 that ripened for 2months was mainly composed of the SLAB L. helveticus and L. delbrueckii. An evaluation of the free-DNA fraction through LH-PCR identified those species that had a high degree of lysis. Data on the dynamics of bacterial growth and lysis were evaluated with respect to the volatile profile and the organic acid content of the two cheeses after 13months of ripening, producing very different results. Cheese from dairy 1 showed a higher content of free fatty acids, particularly those deriving from milk fat lipolysis, benzaldehyde and organic acids, such as pGlu and citric. In contrast, cheese from dairy 2 had a greater amount of ketones, alcohols, hydrocarbons, acetic acid and propionic acid. Based on these results, we can conclude that

  1. Genomics of Probiotic Bacteria

    O'Flaherty, Sarah; Goh, Yong Jun; Klaenhammer, Todd R.

    Probiotic bacteria from the Lactobacillus and Bifidobacterium species belong to the Firmicutes and the Actinobacteria phylum, respectively. Lactobacilli are members of the lactic acid bacteria (LAB) group, a broadly defined family of microorganisms that ferment various hexoses into primarily lactic acid. Lactobacilli are typically low G + C gram-positive species which are phylogenetically diverse, with over 100 species documented to date. Bifidobacteria are heterofermentative, high G + C content bacteria with about 30 species of bifidobacteria described to date.

  2. Learning Chemistry from Bacteria

    Clardy, Jon

    2013-01-01

    Dr. Jon Clardy Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University All animals, including humans, originated and evolved on a planet already teeming with bacteria, and the two kingdoms of life have been competing and cooperating through their joint history. Although bacteria are most familiar as pathogens, some bacteria produce small molecules that are essential for the biology of animals and other eukaryotes. This lecture explores some of...

  3. Modeling the fate of glucosinolates during thermal processing of Brassica vegetables

    Sarvan, I.; Verkerk, R.; Dekker, M.

    2012-01-01

    Glucosinolates are secondary metabolites of Brassicavegetables that have been associated with health benefits. The concentrations of these compounds are strongly affected by processing of the vegetables. Various mechanisms are responsible for these changes: Lysis of plant cells and compartments, dif

  4. TMDLs (Total Maximum Daily Loads) for Bacteria Impairments

    Benham, Brian Leslie, 1960-; Zeckoski, Sara C.

    2009-01-01

    When the concentration of bacteria exceeds the state-specified water-quality criteria, the water is deemed to have a bacteria or pathogen impairment. This publication explains how bacteria impairments are determined and how this relates to the TMDL process.

  5. Chryseobacterium indologenes, novel mannanase-producing bacteria

    Surachai Rattanasuk

    2009-10-01

    Full Text Available Mannanase is a mannan degrading enzyme which is produced by microorganisms, including bacteria. This enzyme can be used in many industrial processes as well as for improving the quality of animal feeds. The aim of the present study was toscreen and characterize the mannanase-producing bacteria. Two genera of bacteria were isolated from Thai soil samples,fermented coconut, and fertilizer. Screening was carried out on agar plates containing mannan stained with iodine solution.The bacteria were identified by partial 16S rRNA gene sequence, biochemical test and morphology, respectively. The mannanase activity was determined by zymogram and DNS method. Two strains of bacteria with mannanase activity were identified as Bacillus and Chryseobacterium. This is the first report of mannanase-producing Chryseobacterium.

  6. Isolation and Expression of the Lysis Genes of Actinomyces naeslundii Phage Av-1

    Delisle, Allan L.; Barcak, Gerard J.; Guo, Ming

    2006-01-01

    Like most gram-positive oral bacteria, Actinomyces naeslundii is resistant to salivary lysozyme and to most other lytic enzymes. We are interested in studying the lysins of phages of this important oral bacterium as potential diagnostic and therapeutic agents. To identify the Actinomyces phage genes encoding these species-specific enzymes in Escherichia coli, we constructed a new cloning vector, pAD330, that can be used to enrich for and isolate phage holin genes, which are located adjacent t...

  7. Interactions of the algicidal bacterium Kordia algicida with diatoms: regulated protease excretion for specific algal lysis.

    Carsten Paul

    Full Text Available Interactions of planktonic bacteria with primary producers such as diatoms have great impact on plankton population dynamics. Several studies described the detrimental effect of certain bacteria on diatoms but the biochemical nature and the regulation mechanism involved in the production of the active compounds remained often elusive. Here, we investigated the interactions of the algicidal bacterium Kordia algicida with the marine diatoms Skeletonema costatum, Thalassiosira weissflogii, Phaeodactylum tricornutum, and Chaetoceros didymus. Algicidal activity was only observed towards the first three of the tested diatom species while C. didymus proved to be not susceptible. The cell free filtrate and the >30 kDa fraction of stationary K. algicida cultures is fully active, suggesting a secreted algicidal principle. The active supernatant from bacterial cultures exhibited high protease activity and inhibition experiments proved that these enzymes are involved in the observed algicidal action of the bacteria. Protease mediated interactions are not controlled by the presence of the alga but dependent on the cell density of the K. algicida culture. We show that protease release is triggered by cell free bacterial filtrates suggesting a quorum sensing dependent excretion mechanism of the algicidal protein. The K. algicida / algae interactions in the plankton are thus host specific and under the control of previously unidentified factors.

  8. Interactions of the algicidal bacterium Kordia algicida with diatoms: regulated protease excretion for specific algal lysis.

    Paul, Carsten; Pohnert, Georg

    2011-01-01

    Interactions of planktonic bacteria with primary producers such as diatoms have great impact on plankton population dynamics. Several studies described the detrimental effect of certain bacteria on diatoms but the biochemical nature and the regulation mechanism involved in the production of the active compounds remained often elusive. Here, we investigated the interactions of the algicidal bacterium Kordia algicida with the marine diatoms Skeletonema costatum, Thalassiosira weissflogii, Phaeodactylum tricornutum, and Chaetoceros didymus. Algicidal activity was only observed towards the first three of the tested diatom species while C. didymus proved to be not susceptible. The cell free filtrate and the >30 kDa fraction of stationary K. algicida cultures is fully active, suggesting a secreted algicidal principle. The active supernatant from bacterial cultures exhibited high protease activity and inhibition experiments proved that these enzymes are involved in the observed algicidal action of the bacteria. Protease mediated interactions are not controlled by the presence of the alga but dependent on the cell density of the K. algicida culture. We show that protease release is triggered by cell free bacterial filtrates suggesting a quorum sensing dependent excretion mechanism of the algicidal protein. The K. algicida / algae interactions in the plankton are thus host specific and under the control of previously unidentified factors. PMID:21695044

  9. A microchip electrophoresis-mass spectrometric platform with double cell lysis nano-electrodes for automated single cell analysis.

    Li, Xiangtang; Zhao, Shulin; Hu, Hankun; Liu, Yi-Ming

    2016-06-17

    Capillary electrophoresis-based single cell analysis has become an essential approach in researches at the cellular level. However, automation of single cell analysis has been a challenge due to the difficulty to control the number of cells injected and the irreproducibility associated with cell aggregation. Herein we report the development of a new microfluidic platform deploying the double nano-electrode cell lysis technique for automated analysis of single cells with mass spectrometric detection. The proposed microfluidic chip features integration of a cell-sized high voltage zone for quick single cell lysis, a microfluidic channel for electrophoretic separation, and a nanoelectrospray emitter for ionization in MS detection. Built upon this platform, a microchip electrophoresis-mass spectrometric method (MCE-MS) has been developed for automated single cell analysis. In the method, cell introduction, cell lysis, and MCE-MS separation are computer controlled and integrated as a cycle into consecutive assays. Analysis of large numbers of individual PC-12 neuronal cells (both intact and exposed to 25mM KCl) was carried out to determine intracellular levels of dopamine (DA) and glutamic acid (Glu). It was found that DA content in PC-12 cells was higher than Glu content, and both varied from cell to cell. The ratio of intracellular DA to Glu was 4.20±0.8 (n=150). Interestingly, the ratio drastically decreased to 0.38±0.20 (n=150) after the cells are exposed to 25mM KCl for 8min, suggesting the cells released DA promptly and heavily while they released Glu at a much slower pace in response to KCl-induced depolarization. These results indicate that the proposed MCE-MS analytical platform may have a great potential in researches at the cellular level. PMID:27207575

  10. Aerobic Anoxygenic Phototrophic Bacteria

    Yurkov, Vladimir V.; Beatty, J. Thomas

    1998-01-01

    The aerobic anoxygenic phototrophic bacteria are a relatively recently discovered bacterial group. Although taxonomically and phylogenetically heterogeneous, these bacteria share the following distinguishing features: the presence of bacteriochlorophyll a incorporated into reaction center and light-harvesting complexes, low levels of the photosynthetic unit in cells, an abundance of carotenoids, a strong inhibition by light of bacteriochlorophyll synthesis, and the inability to grow photosynt...

  11. Tumour Lysis Syndrome Occurring in a Patient with Metastatic Gastrointestinal Stromal Tumour Treated with Glivec (Imatinib Mesylate, Gleevec, STI571

    Elizabeth M. Pinder

    2007-01-01

    Full Text Available Tumour lysis syndrome (TLS is a rare side effect of chemotherapy for solid tumours. It describes the metabolic derangements following rapid and extensive tumour cell death following a good response to chemotherapy. Symptoms are those of metabolic derangement and renal failure. Treatment involves rehydration and correction of metabolic abnormalities. TLS should be considered in high risk groups. We report a case of TLS in a patient with metastatic gastrointestinal stromal tumour treated with imatinib mesylate. To our knowledge, this is the first reported case.

  12. Hyperuricemia and tumor lysis syndrome in children with non-Hodgkin’s lymphoma and acute lymphoblastic leukemia

    Betül Sevinir; Metin Demirkaya; Birol Baytan; Adalet Meral Güneş

    2011-01-01

    Objective: This study aimed to examine the incidence, clinical characteristics, and outcome of hyperuricemia and tumor lysis syndrome (TLS) in children with non-Hodgkin’s lymphoma (NHL) and acute lymphoblastic leukemia (ALL).Materials and Methods: This retrospective study included data from 327 patients (113 NHL and 214 ALL).Results: Hyperuricemia occurred in 26.5% and 12.6% of the patients with NHL and ALL, respectively. The corresponding figures for TLS were 15.9% and 0.47% (p=0.001). All h...

  13. Severe Tumor Lysis Syndrome and Acute Pulmonary Edema Requiring Extracorporeal Membrane Oxygenation Following Initiation of Chemotherapy for Metastatic Alveolar Rhabdomyosarcoma.

    Sanford, Ethan; Wolbrink, Traci; Mack, Jennifer; Grant Rowe, R

    2016-05-01

    We present an 8-year-old male with metastatic alveolar rhabdomyosarcoma (ARMS) who developed precipitous cardiopulmonary collapse with severe tumor lysis syndrome (TLS) 48 hr after initiation of chemotherapy. Despite no detectable pulmonary metastases, acute hypoxemic respiratory failure developed, requiring extracorporeal membrane oxygenation (ECMO). Although TLS has been reported in disseminated ARMS, this singular case of life-threatening respiratory deterioration developing after initiation of chemotherapy presented unique therapeutic dilemmas. We review the clinical aspects of this case, including possible mechanisms of respiratory failure, and discuss the role of ECMO utilization in pediatric oncology. PMID:26713672

  14. Metallization of bacteria cells

    LI; Xiangfeng; (黎向锋); LI; Yaqin; (李雅芹); CAI; Jun; (蔡军); ZHANG; Deyuan; (张德远)

    2003-01-01

    Bacteria cells with different standard shapes are well suited for use as templates for the fabrication of magnetic and electrically conductive microstructures. In this paper, metallization of bacteria cells is demonstrated by an electroless deposition technique of nickel-phosphorus initiated by colloid palladium-tin catalyst on the surfaces of Citeromyces matritensis and Bacillus cereus. The activated and metallized bacteria cells have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction analysis (XRD). Results showed that both Citeromyces matritensis and Bacillus cereus had no deformation in shape after metallization; the metallized films deposited on the surfaces of bacteria cells are homogeneous in thickness and noncrystalline in phase structure. The kinetics of colloid palladium-tin solution and electroless plating on bacteria cells is discussed.

  15. Effects of bacterially produced precipitates on the metabolism of sulfate reducing bacteria during the bio-treatment process of copper-containing wastewater

    2010-01-01

    A large volume of bacterially produced precipitates are generated during the bio-treatment of heavy metal wastewater.The composition of the bacterially produced precipitates and its effects on sulfate reducing bacteria (SRB) in copper-containing waste stream were evaluated in this study.The elemental composition of the microbial precipitate was studied using electrodispersive X-ray spectroscopy (EDX),and it was found that the ratio of S:Cu was 1.12.Combining with the results of copper distribution in the SRB metabolism culture,which was analyzed by the sequential extraction procedure,copper in the precipitates was determined as covellite (CuS).The bacterially produced precipitates caused a decrease of the sulfate reduction rate,and the more precipitates were generated,the lower the sulfate reduction rate was.The particle sizes of bacterially generated covellite were ranging from 0.03 to 2 m by particles size distribution (PSD) analysis,which was smaller than that of the SRB cells.Transmission electron microscopy (TEM) analysis showed that the microbial covellite was deposited on the surface of the cell.The effects of the microbial precipitate on SRB metabolism were found to be weakened by increasing the precipitation time and adding microbial polymeric substances in later experiments.These results provided direct evidence that the SRB activity was inhibited by the bacterially produced covellite,which enveloped the bacterium and thus affected the metabolism of SRB on mass transfer.

  16. Spray drying of dairy bacteria: New opportunities to improve the viability of bacteria powders

    Dolivet, Anne; Mejean, Serge; Hervé, C.; Jeantet, Romain

    2013-01-01

    The most frequently used technique for dehydration of dairy bacteria is freeze drying. Of the other possible preservation techniques used in the dairy industry to produce large amounts of dairy ingredients at commercially viable processing costs, spray drying is one of the main processing tools and the cost is 10 times lower than that of freeze drying. In this work, some examples are presented for different species of dairy bacteria with respect to spray-drying processes (as an alternative ap...

  17. Functional bacteria and process metabolism of the Denitrifying Sulfur conversion-associated Enhanced Biological Phosphorus Removal (DS-EBPR) system: An investigation by operating the system from deterioration to restoration.

    Guo, Gang; Wu, Di; Hao, Tianwei; Mackey, Hamish Robert; Wei, Li; Wang, Haiguang; Chen, Guanghao

    2016-05-15

    A sulfur conversion-associated Enhanced Biological Phosphorus (P) Removal (EBPR) system is being developed to cater for the increasing needs to treat saline/brackish wastewater resulting from seawater intrusion into groundwater and sewers and frequent use of sulfate coagulants during drinking water treatment, as well as to meet the demand for eutrophication control in warm climate regions. However, the major functional bacteria and metabolism in this emerging biological nutrient removal system are still poorly understood. This study was thus designed to explore the functional microbes and metabolism in this new EBPR system by manipulating the deterioration, failure and restoration of a lab-scale system. This was achieved by changing the mixed liquor suspended solids (MLSS) concentration to monitor and evaluate the relationships among sulfur conversion (including sulfate reduction and sulfate production), P removal, variation in microbial community structures, and stoichiometric parameters. The results show that the stable Denitrifying Sulfur conversion-associated EBPR (DS-EBPR) system was enriched by sulfate-reducing bacteria (SRB) and sulfide-oxidizing bacteria (SOB). These bacteria synergistically participated in this new EBPR process, thereby inducing an appropriate level of sulfur conversion crucial for achieving a stable DS-EBPR performance, i.e. maintaining sulfur conversion intensity at 15-40 mg S/L, corresponding to an optimal sludge concentration of 6.5 g/L. This range of sulfur conversion favors microbial community competition and various energy flows from internal polymers (i.e. polysulfide or elemental sulfur (poly-S(2-)/S(0)) and poly-β-hydroxyalkanoates (PHA)) for P removal. If this range was exceeded, the system might deteriorate or even fail due to enrichment of glycogen-accumulating organisms (GAOs). Four methods of restoring the failed system were investigated: increasing the sludge concentration, lowering the salinity or doubling the COD

  18. Interactions between ectomycorrhizal associations and bacteria

    Marupakula, Srisailam

    2016-01-01

    Boreal forest podzol soils have vertically stratified horizons with different physico-chemical characteristics and high microbial diversity. Ectomycorrhizal fungi play key roles in accessing nutrients from both organic and mineral substrates. The role of associated bacteria in these processes is still poorly understood. The aim of the studies described in this thesis was to improve understanding of the distribution, diversity and community structure of fungi and bacteria on roots and in soil ...

  19. How Bacteria Turn Fiber into Food

    Martens, Eric C.; Lowe, Elisabeth C.; Chiang, Herbert; Nicholas A Pudlo; Wu, Meng; McNulty, Nathan P.; Abbott, D Wade; Henrissat, Bernard; Gilbert, Harry J.; Bolam, David N.; Jeffrey I Gordon

    2011-01-01

    Symbiotic bacteria inhabiting the human gut have evolved under intense pressure to utilize complex carbohydrates, primarily plant cell wall glycans in our diets. These polysaccharides are not digested by human enzymes, but are processed to absorbable short chain fatty acids by gut bacteria. The Bacteroidetes, one of two dominant bacterial phyla in the adult gut, possess broad glycan-degrading abilities. These species use a series of membrane protein complexes, termed Sus-like systems, for cat...

  20. Dual-species biofilms formation by Escherichia coli O157:H7 and environmental bacteria isolated from fresh-cut processing plants

    Biofilm formation is a mechanism adapted by many microorganisms that enhances the survival in stressful environments. In food processing facilities, bacterial strains with strong biofilm forming capacities are more likely to survive the daily cleaning and disinfection. Foodborne bacterial pathogens,...

  1. Indicator For Pseudomonas Bacteria

    Margalit, Ruth

    1990-01-01

    Characteristic protein extracted and detected. Natural protein marker found in Pseudomonas bacteria. Azurin, protein containing copper readily extracted, purified, and used to prepare antibodies. Possible to develop simple, fast, and accurate test for marker carried out in doctor's office.

  2. Isolation of radiation-resistant bacteria without exposure to irradiation

    Resistance to desiccation was utilized in the selection of highly radiation-resistant asporogenous bacteria from nonirradiated sources. A bacterial suspension in phosphate buffer was dried in a thin film at 250C and 33% relative humidity. Storage under these conditions for 15 days or more reduced the number of radiation-sensitive bacteria. Further selection for radiation-resistant bacteria was obtained by irradiation of bacteria on velveteen in the replication process, therby avoiding the toxic effect of irradiated media. The similarity of radiation resistance and identifying characteristics in irradiated and non-irradiated isolates should allay some concerns that highly radiation-resistance bacteria have been permanently altered by radiation selection

  3. Very High Throughput Electrical Cell Lysis and Extraction of Intracellular Compounds Using 3D Carbon Electrodes in Lab-on-a-Chip Devices

    Philippe Renaud

    2012-08-01

    Full Text Available Here we present an electrical lysis throughput of 600 microliters per minute at high cell density (108 yeast cells per ml with 90% efficiency, thus improving the current common throughput of one microliter per minute. We also demonstrate the extraction of intracellular luciferase from mammalian cells with efficiency comparable to off-chip bulk chemical lysis. The goal of this work is to develop a sample preparation module that can act as a stand-alone device or be integrated to other functions already demonstrated in miniaturized devices, including sorting and analysis, towards a true lab-on-a-chip.

  4. Modelling and predicting the simultaneous growth of Listeria monocytogenes and psychrotolerant lactic acid bacteria in processed seafood and mayonnaise-based seafood salads

    Mejlholm, Ole; Dalgaard, Paw

    2015-01-01

    A new combined model for Listeria monocytogenes and psychrotolerant Lactobacillus spp. was constructed and evaluated for processed seafood and mayonnaise-based seafood salads. The new model was constructed by combining existing cardinal parameter models for L. monocytogenes and Lactobacillus spp....

  5. An integrated direct loop-mediated isothermal amplification microdevice incorporated with an immunochromatographic strip for bacteria detection in human whole blood and milk without a sample preparation step.

    Lee, Dohwan; Kim, Yong Tae; Lee, Jee Won; Kim, Do Hyun; Seo, Tae Seok

    2016-05-15

    We have developed an integrated direct loop-mediated isothermal amplification (Direct LAMP) microdevice incorporated with an immunochromatographic strip (ICS) to identify bacteria contaminated in real samples. The Direct LAMP is a novel isothermal DNA amplification technique which does not require thermal cycling steps as well as any sample preparation steps such as cell lysis and DNA extraction for amplifying specific target genes. In addition, the resultant amplicons were colorimetrically detected on the ICS, thereby enabling the entire genetic analysis process to be simplified. The two functional units (Direct LAMP and ICS) were integrated on a single device without use of the tedious and complicated microvalve and tubing systems. The utilization of a slidable plate allows us to manipulate the fluidic control in the microchannels manually and the sequential operation of the Direct LAMP and ICS detection could be performed by switching the slidable plate to each functional unit. Thus, the combination of the direct isothermal amplification without any sample preparation and thermal cycling steps, the ICS based amplicon detection by naked eyes, and the slidable plate to eliminate the microvalves in the integrated microdevice would be an ideal platform for point-of-care DNA diaganotics. On the integrated Direct LAMP-ICS microdevice, we could analyze Staphylococcus aureus (S. aureus) and Escherichia coli O157:H7 (E. coli O157:H7) contaminated in human whole blood or milk at a single-cell level within 1h. PMID:26710344

  6. The talking language in some major Gram-negative bacteria.

    Banerjee, Goutam; Ray, Arun Kumar

    2016-08-01

    Cell-cell interaction or quorum sensing (QS) is a vital biochemical/physiological process in bacteria that is required for various physiological functions, including nutrient uptake, competence development, biofilm formation, sporulation, as well as for toxin secretion. In natural environment, bacteria live in close association with other bacteria and interaction among them is crucial for survival. The QS-regulated gene expression in bacteria is a cell density-dependent process and the initiation process depends on the threshold level of the signaling molecule, N-acyl-homoserine lactone (AHL). The present review summarizes the QS signal and its respective circuit in Gram-negative bacteria. Most of the human pathogens belong to Gram-negative group, and only a few of them cause disease through QS system. Thus, inhibition of pathogenic bacteria is important. Use of antibiotics creates a selective pressure (antibiotics act as natural selection factor to promote one group of bacteria over another group) for emerging multidrug-resistant bacteria and will not be suitable for long-term use. The alternative process of inhibition of QS in bacteria using different natural and synthetic molecules is called quorum quenching. However, in the long run, QS inhibitors or blockers may also develop resistance, but obviously it will solve some sort of problems. In this review, we also have stated the mode of action of quorum-quenching molecule. The understanding of QS network in pathogenic Gram-negative bacteria will help us to solve many health-related problems in future. PMID:27062655

  7. Bacteria and viruses of the ice-free aquatic area of the Barents Sea at the beginning of polar night.

    Shirokolobova, T I; Zhichkin, A P; Venger, M P; Vodopyanova, V V; Moiseev, D V

    2016-07-01

    The most massive components of the microplankton were studied in the open sea waters for the first time at the end of the autumn season. It has been found that abundance of the virio- and bacterioplankton exceeded that observed in winter in the coastal zone. Against the background of a relatively uniform distribution of bacteria, the viral abundance and the lysis-mediated bacterioplankton death rate reached the maximum values in the most cold and salty waters of the northern sea areas. PMID:27595827

  8. Modelling and predicting the simultaneous growth of Listeria monocytogenes and psychrotolerant lactic acid bacteria in processed seafood and mayonnaise-based seafood salads.

    Mejlholm, Ole; Dalgaard, Paw

    2015-04-01

    A new combined model for Listeria monocytogenes and psychrotolerant Lactobacillus spp. was constructed and evaluated for processed seafood and mayonnaise-based seafood salads. The new model was constructed by combining existing cardinal parameter models for L. monocytogenes and Lactobacillus spp. using the classical Jameson effect to model microbial interaction. Maximum population density (MPD) values of L. monocytogenes were accurately predicted in processed seafood with a known initial cell concentration of Lactobacillus spp. For these experiments, average MPD values of 4.5 and 4.3 log (cfu/g) were observed and predicted, respectively for L. monocytogenes. In seafood salads, growth of L. monocytogenes continued at a reduced growth rate after Lactobacillus sakei had reached their MPD. This growth pattern was successfully described by an expanded version of the classical Jameson effect model, but only for products with pH of 6.0 or higher. For seafood salads with pH below 6.0 the performance of the new model was unacceptable, primarily due to prediction of no-growth by L. monocytogenes when growth was actually observed. Within its range of applicability the new model can be valuable for risk assessment and risk management of processed seafood as well as for evaluating the compliance of products with the EU regulation for ready-to-eat foods. PMID:25475260

  9. Label-free bacteria detection using evanescent mode of a suspended core terahertz fiber

    Mazhorova, Anna; Ng, Andy; Chinnappan, Raja; Zourob, Mohammed; Skorobogatiy, Maksim

    2011-01-01

    We propose for the first time an E. coli bacteria sensor based on the evanescent field of the fundamental mode of a suspended-core terahertz fiber. The sensor is capable of E. coli detection at concentrations in the range of 104-109 cfu/ml. The polyethylene fiber features a 150 {\\mu}m core suspended by three deeply sub-wavelength bridges in the center of a 5.1 mm-diameter cladding tube. The fiber core is biofunctionalized with T4 bacteriophages which bind and eventually destroy (lyse) their bacterial target. Using environmental SEM we demonstrate that E. coli is first captured by the phages on the fiber surface. After 25 minutes, most of the bacteria is infected by phages and then destroyed with ~1{\\mu}m-size fragments remaining bound to the fiber surface. The bacteria-binding and subsequent lysis unambiguously correlate with a strong increase of the fiber absorption. This signal allows the detection and quantification of bacteria concentration. Presented bacteria detection method is label-free and it does no...

  10. Polycyclic aromatic hydrocarbon-contaminated soils: bioaugmentation of autochthonous bacteria and toxicological assessment of the bioremediation process by means of Vicia faba L.

    Ruffini Castiglione, Monica; Giorgetti, Lucia; Becarelli, Simone; Siracusa, Giovanna; Lorenzi, Roberto; Di Gregorio, Simona

    2016-04-01

    Two bacterial strains, Achromobacter sp. (ACH01) and Sphingomonas sp. (SPH01), were isolated from a heavily polycyclic aromatic hydrocarbon (PAH)-contaminated soil (5431.3 ± 102.3 ppm) for their capacity to use a mixture of anthracene, pyrene, phenanthrene and fluorene as sole carbon sources for growth and for the capacity to produce biosurfactants. The two strains were exploited for bioaugmentation in a biopile pilot plant to increase the bioavailability and the degradation of the residual PAH contamination (99.5 ± 7.1 ppm) reached after 9 months of treatment. The denaturing gel gradient electrophoresis (DGGE) profile of the microbial ecology of the soil during the experimentation showed that the bioaugmentation approach was successful in terms of permanence of the two strains in the soil in treatment. The bioaugmentation of the two bacterial isolates positively correlated with the PAH depletion that reached 7.9 ± 2 ppm value in 2 months of treatment. The PAH depletion was assessed by the loss of the phyto-genotoxicity of soil elutriates on the model plant Vicia faba L., toxicological assessment adopted also to determine the minimum length of the decontamination process for obtaining both the depletion of the PAH contamination and the detoxification of the soil at the end of the process. The intermediate phases of the bioremediation process were the most significant in terms of toxicity, inducing genotoxic effects and selective DNA fragmentation in the stem cell niche of the root tip. The selective DNA fragmentation can be related to the selective induction of cell death of mutant stem cells that can compromise offsprings. PMID:26769476

  11. Effect of spirapril and hydrochlorothiazide on platelet function and euglobulin clot lysis time in patients with mild hypertension

    Fonitz, Gitte (Gleerup); Petersen, J R; Mehlsen, J; Winther, Kaj

    1996-01-01

    Thirteen patients with mild hypertension (untreated diastolic blood pressure of 95 to 114 mmHg) received, in random order, three successive treatments of four weeks with placebo, spirapril (6 mg daily), or hydrochlorothiazide (HCT2) (24 mg daily). At the end of each treatment, blood samples for...... assessment of platelet aggregation and platelet release of platelet factor 4 (PF4) and for assessment of fibrinolysis, estimated by tissue plasminogen activator (t-PA), plasminogen activator inhibitor-type 1 (PAI-1), and euglobulin clot lysis time (ECLT), were taken, first at rest, then immediately after...... five to ten minutes of vigorous exercise, and finally after the subsequent hour of recovery rest. Platelet aggregation induced in vitro by adrenaline significantly decreased during treatment with HCT2, the threshold rising to 10 microM as compared with 1.0 with placebo (P <0.05) at rest, and the...

  12. 余甘子褐色乳酸菌饮料加工工艺研究%Study on the Processing Technology of Brown Emblica Lactic Acid Bacteria Beverage

    杨洋; 高航; 段艳珠; 崔立红; 段玉禄

    2015-01-01

    以脱脂乳粉、余甘子为主要原料,研究了余甘子褐色乳酸菌饮料的制备工艺条件。通过正交试验研究了余甘子褐色乳酸菌饮料产品配方及乳化稳定剂的复配方案。结果表明:余甘子褐色乳酸菌饮料最适配料为白砂糖6.0%、余甘子汁2.0%、蜂蜜1.0%、甜橙香精0.08%。余甘子褐色乳酸菌饮料最佳稳定剂为可溶性大豆多糖0.20%、果胶0.30%、三聚磷酸钠0.05%。制得的余甘子褐色乳酸菌饮料色泽呈黄褐色,具有甜橙特征风味,口感清爽适口,并具有一定的营养保健功能。%skim milk powder and emblic leaflfower fruit are used as raw material and the manufacture process conditions of brown emblica lactic acid bacteria beverage were discussed. Product formula and compositional formulation of emulsion stabilizer were studied by orthogonal experiments. The results showed that the most adapted material formula of brown emblica lactic acid bacteria beverage was as fol ows:white sugar was 6.0%, phyl anthus emblica juice was 2.0%, honey was 1.0%, and an orange lfavour was 0.08%. The best stabilizer compositional formulation was as fol ows:soluble soybean polysaccharide was 0.20%, pectin was 0.30%, and sodium tripolyphosphate was 0.05%. The resulting yel owish-brown color of brown emblica lactic acid bacteria beverage, with characteristic lfavor of orange, fresh taste palatability, and has a certain nutrition and health function.

  13. Design and application of the method for isolating magnetotactic bacteria

    XIAO Zhijie; LIAN Bin; CHEN Jun; H. Henry Teng

    2007-01-01

    A simple apparatus was designed to effectively isolate magnetotactic bacteria from soils or sediments based on their magnetotaxis. Through a series of processes including sample incubation, MTB harvesting, isolation, purification and identification, several strains of bacteria were isolated from the samples successfully. By Transmission Electron Microscopy (TEM) and Energy-Dispersive X-ray Analysis (EDXA), these bacteria were certificated to be magnetotactic bacteria. The phylogenetic relationship between the isolated magnetic strains and some known magnetotactic bacteria was inferred by the construction of phylogenetic tree based on 16SrDNA sequences. This apparatus has been proven to have the advantages of being inexpensive, simple to assemble, easy to perform and highly efficient to isolate novel magnetotactic bacteria. The research indicated that the combined approach of harvesting MTB by home-made apparatus and the method of plate colony isolation could purify and isolate magnetotactic bacteria effectively.

  14. CADM1/TSLC1 Identifies HTLV-1-Infected Cells and Determines Their Susceptibility to CTL-Mediated Lysis

    Tanaka, Yuetsu; Taylor, Graham P.; Bangham, Charles R. M.

    2016-01-01

    Human T cell lymphotropic virus-1 (HTLV-1) primarily infects CD4+ T cells, causing inflammatory disorders or a T cell malignancy in 5% to 10% of carriers. The cytotoxic T lymphocyte (CTL) response is a key factor that controls the viral load and thus the risk of disease. The ability to detect the viral protein Tax in primary cells has made it possible to estimate the rate at which Tax-expressing infected cells are eliminated by CTLs in persistently infected people. However, most HTLV-1-infected cells are Tax–at a given time, and their immunophenotype is poorly defined. Here, we aimed to identify a cell-surface molecule expressed by both Tax+ and Tax–HTLV-1-infected cells and use it to analyse the CTL response in fresh peripheral blood mononuclear cells. Cell adhesion molecule 1 (CADM1/TSLC1) was the best single marker of HTLV-1 infection, identifying HTLV-1-infected cells with greater sensitivity and specificity than CD25, CCR4 or ICAM-1. CADM1+CD4+ T cells carried a median of 65% of proviral copies in peripheral blood. In a cohort of 23 individuals, we quantified the rate of CTL-mediated killing of Tax+ and Tax−CADM1+ cells. We show that CADM1 expression is associated with enhanced susceptibility of infected cells to CTL lysis: despite the immunodominance of Tax in the CTL response, Tax+CADM1– cells were inefficiently lysed by CTLs. Upregulation of the CADM1 ligand CRTAM on CD8+ T cells correlated with efficient lysis of infected cells. Tax–CADM1+ cells were lysed at a very low rate by autologous CTLs, however, were efficiently killed when loaded with exogenous peptide antigen. High expression of CADM1 on most HTLV-1-infected cells in the face of enhanced CTL counterselection implies that CADM1 confers a strong benefit on the virus. PMID:27105228

  15. The Cell Lysis Activity of the Streptococcus agalactiae Bacteriophage B30 Endolysin Relies on the Cysteine, Histidine-Dependent Amidohydrolase/Peptidase Domain

    Donovan, David M.; Foster-Frey, Juli; Dong, Shengli; Rousseau, Geneviève M.; Moineau, Sylvain; Pritchard, David G.

    2006-01-01

    The Streptococcus agalactiae bacteriophage B30 endolysin contains three domains: cysteine, histidine-dependent amidohydrolase/peptidase (CHAP), Acm glycosidase, and the SH3b cell wall binding domain. Truncations and point mutations indicated that the Acm domain requires the SH3b domain for activity, while the CHAP domain is responsible for nearly all the cell lysis activity.

  16. Daratumumab-mediated lysis of primary multiple myeloma cells is enhanced in combination with the human anti-KIR antibody IPH2102 and lenalidomide

    Nijhof, Inger S.; van Bueren, Jeroen J. Lammerts; van Kessel, Berris; Andre, Pascale; Morel, Yannis; Lokhorst, Henk M.; van de Donk, Niels W.C.J.; Parren, Paul W.H.I.; Mutis, Tuna

    2015-01-01

    Despite recent treatment improvements, multiple myeloma remains an incurable disease. Since antibody-dependent cell-mediated cytotoxicity is an important effector mechanism of daratumumab, we explored the possibility of improving daratumumab-mediated cell-mediated cytotoxicity by blocking natural killer cell inhibitory receptors with the human monoclonal anti-KIR antibody IPH2102, next to activation of natural killer cells with the immune modulatory drug lenalidomide. In 4-hour antibody-dependent cell-mediated cytotoxicity assays, IPH2102 did not induce lysis of multiple myeloma cell lines, but it did significantly augment daratumumab-induced myeloma cell lysis. Also in an ex vivo setting, IPH2102 synergistically improved daratumumab-dependent lysis of primary myeloma cells in bone marrow mononuclear cells (n=21), especially in patients carrying the FcγRIIIa-158F allele or the FcγRIIa-131R allele, who bind IgG1 with lower affinity than patients carrying the FcγRIIIa-158V allele or the FcγRIIa-131H allele. Finally, a further synergistically improved myeloma cell lysis with the daratumumab-IPH2102 combination was observed by adding lenalidomide, which suggests that more effective treatment strategies can be designed for multiple myeloma by combining daratumumab with agents that independently modulate natural killer cell function. PMID:25510242

  17. Direct identification of bacteria in positive blood culture bottles by matrix-assisted laser desorption ionisation time-of-flight mass spectrometry.

    Bernard La Scola

    Full Text Available BACKGROUND: With long delays observed between sampling and availability of results, the usefulness of blood cultures in the context of emergency infectious diseases has recently been questioned. Among methods that allow quicker bacterial identification from growing colonies, matrix-assisted laser desorption ionisation time-of-flight (MALDI-TOF mass spectrometry was demonstrated to accurately identify bacteria routinely isolated in a clinical biology laboratory. In order to speed up the identification process, in the present work we attempted bacterial identification directly from blood culture bottles detected positive by the automate. METHODOLOGY/PRINCIPAL FINDINGS: We prospectively analysed routine MALDI-TOF identification of bacteria detected in blood culture by two different protocols involving successive centrifugations and then lysis by trifluoroacetic acid or formic acid. Of the 562 blood culture broths detected as positive by the automate and containing one bacterial species, 370 (66% were correctly identified. Changing the protocol from trifluoroacetic acid to formic acid improved identification of Staphylococci, and overall correct identification increased from 59% to 76%. Lack of identification was observed mostly with viridans streptococci, and only one false positive was observed. In the 22 positive blood culture broths that contained two or more different species, only one of the species was identified in 18 samples, no species were identified in two samples and false species identifications were obtained in two cases. The positive predictive value of bacterial identification using this procedure was 99.2%. CONCLUSIONS/SIGNIFICANCE: MALDI-TOF MS is an efficient method for direct routine identification of bacterial isolates in blood culture, with the exception of polymicrobial samples and viridans streptococci. It may replace routine identification performed on colonies, provided improvement for the specificity of blood culture

  18. Study of Lactobacillus as Probiotic Bacteria

    J Nowroozi

    2004-07-01

    Full Text Available Because of inhibitory effect, selected probiotic lactobacilli may be used as biological preservative, so, the aim of this study was to present some data on lactobacillus as probiotic bacteria. Lactic acid bacteria were isolated from sausage. Each isolate of lactobacillus species was identified by biochemical tests and comparing their sugar fermentation pattern. Antibacterial activities were done by an agar spot, well diffusion and blank disk method. Enzyme sensitivity of supernatant fluid and concentrated cell free culture after treatment with α-amylase, lysozyme and trypsin was determined. The isolated bacteria were Lacto. plantarum, Lacto delbruekii, Lacto. acidophilus, Lacto. brevis. The isolated bacteria had strong activity against indicator strains. The antibacterial activity was stable at 100ºC for 10 min and at 56ºC for 30 min, but activity was lost after autoclaving. The maximum production of plantaricin was obtained at 25 - 30ºC at pH 6.5. Because, lactobacilli that used to process sausage fermentation are producing antimicrobial activity with heat stability bacteriocin, so, these bacteria may be considered to be a healthy probiotic diet. Lactobacilli originally isolated from meat products are the best condidates as probiotic bacteria to improve the microbiological safety of these foods.

  19. Molecular probe technology detects bacteria without culture

    Hyman Richard W

    2012-03-01

    Full Text Available Abstract Background Our ultimate goal is to detect the entire human microbiome, in health and in disease, in a single reaction tube, and employing only commercially available reagents. To that end, we adapted molecular inversion probes to detect bacteria using solely a massively multiplex molecular technology. This molecular probe technology does not require growth of the bacteria in culture. Rather, the molecular probe technology requires only a sequence of forty sequential bases unique to the genome of the bacterium of interest. In this communication, we report the first results of employing our molecular probes to detect bacteria in clinical samples. Results While the assay on Affymetrix GenFlex Tag16K arrays allows the multiplexing of the detection of the bacteria in each clinical sample, one Affymetrix GenFlex Tag16K array must be used for each clinical sample. To multiplex the clinical samples, we introduce a second, independent assay for the molecular probes employing Sequencing by Oligonucleotide Ligation and Detection. By adding one unique oligonucleotide barcode for each clinical sample, we combine the samples after processing, but before sequencing, and sequence them together. Conclusions Overall, we have employed 192 molecular probes representing 40 bacteria to detect the bacteria in twenty-one vaginal swabs as assessed by the Affymetrix GenFlex Tag16K assay and fourteen of those by the Sequencing by Oligonucleotide Ligation and Detection assay. The correlations among the assays were excellent.

  20. The Effects and Revelations of Manufacturing Process on the Health Benefits of Probiotic Bacteria%制造工艺对益生菌健康效应的影响及其启示

    刘茂柯; 唐玉明; 曹晓涵; 任道群; 姚万春; 敖晓琳

    2014-01-01

    近年来的研究表明,益生菌产品的功效往往独立于活菌数存在并在生产加工过程中受到多种因素的影响。通过对相关研究报道的收集与分析,总结了生产环节影响益生菌健康效应的主要因素,并针对产品研发过程中应注意的问题和如何提高益生菌产品的功效提出了一些初步的观点和认识。%Recent researches indicated that the functionality of probiotic was affected by multiple factors during the manufacturing process, while the functionality was independent of viable bacteria number. In this paper, summarizes the main factors influencing the functionality of probiotic in the manufacturing process , and recommends some suggestions forward on the matters needing attention about the probiotic products during which were produced and on how to develop the efficacy of probiotic foods.

  1. 制造工艺对益生菌健康效应的影响及其启示%The Effects and Revelations of Manufacturing Process on the Health Benefits of Probiotic Bacteria

    刘茂柯; 唐玉明; 曹晓涵; 任道群; 姚万春; 敖晓琳

    2014-01-01

    Recent researches indicated that the functionality of probiotic was affected by multiple factors during the manufacturing process, while the functionality was independent of viable bacteria number. In this paper, summarizes the main factors influencing the functionality of probiotic in the manufacturing process , and recommends some suggestions forward on the matters needing attention about the probiotic products during which were produced and on how to develop the efficacy of probiotic foods.%近年来的研究表明,益生菌产品的功效往往独立于活菌数存在并在生产加工过程中受到多种因素的影响。通过对相关研究报道的收集与分析,总结了生产环节影响益生菌健康效应的主要因素,并针对产品研发过程中应注意的问题和如何提高益生菌产品的功效提出了一些初步的观点和认识。

  2. Immunity to intracellular bacteria

    Stefan H. E. Kaufmann; Follows, George A.; Martin E. Munik

    1992-01-01

    Immunity to intracellular bacteria including Mycobacterium tuberculosis. Mycobacterium leprae, and Listeria monocytogenes depends on specific T cells. Evidence to be described suggests that CD4 (alpha/beta)T cells which interact with each other and with macrophages contribute to acquired resistence against as well as pathogenesis of intracellular bacterial infections.

  3. Immunity to intracellular bacteria

    Stefan H. E. Kaufmann

    1992-01-01

    Full Text Available Immunity to intracellular bacteria including Mycobacterium tuberculosis. Mycobacterium leprae, and Listeria monocytogenes depends on specific T cells. Evidence to be described suggests that CD4 (alpha/betaT cells which interact with each other and with macrophages contribute to acquired resistence against as well as pathogenesis of intracellular bacterial infections.

  4. Biological control of potato black scurf by rhizosphere associated bacteria

    Mohsin Tariq

    2010-06-01

    Full Text Available The present work was carried out to study the potential of plant rhizosphere associated bacteria for the biocontrol of potato black scurf disease caused by Rhizoctonia solani Khun AG-3. A total of twenty-eight bacteria isolated from diseased and healthy potato plants grown in the soil of Naran and Faisalabad, Pakistan were evaluated for their antagonistic potential. Nine bacterial strains were found to be antagonistic in vitro, reduced the fungal growth and caused the lysis of sclerotia of R. solani in dual culture assay as well as in extracellular metabolite efficacy test. The selected antagonistic strains were further tested for the production and efficacy of volatile and diffusible antibiotics, lytic enzymes and siderophores against R. solani. Selected antagonistic bacteria were also characterized for growth promoting attributes i.e., phosphate solubilization, nitrogen fixation and indole acetic acid production. Biocontrol efficacy and percent yield increase by these antagonists was estimated in greenhouse experiment. Statistical analysis showed that two Pseudomonas spp. StT2 and StS3 were the most effective with 65.1 and 73.9 percent biocontrol efficacy, as well as 87.3 and 98.3 percent yield increase, respectively. Potential antagonistic bacterial strain StS3 showed maximum homology to Pseudomonas sp. as determined by 16S rRNA gene sequencing. These results suggest that bacterial isolates StS3 and StT2 have excellent potential to be used as effective biocontrol agents promoting plant growth with reduced disease incidence.

  5. Bacteria in Crude Oil Survived Autoclaving and Stimulated Differentially by Exogenous Bacteria

    Gong, Xiao-Cui; Liu, Ze-Shen; Guo, Peng; Chi, Chang-Qiao; Chen, Jian; Wang, Xing-Biao; Tang, Yue-Qin; Wu, Xiao-Lei; Liu, Chun-Zhong

    2012-01-01

    Autoclaving of crude oil is often used to evaluate the hydrocarbon-degrading abilities of bacteria. This may be potentially useful for bioaugmentation and microbial enhanced oil recovery (MEOR). However, it is not entirely clear if “endogenous” bacteria (e.g., spores) in/on crude oil survive the autoclaving process, or influence subsequent evaluation of the hydrocarbon-degradation abilities of the “exogenous” bacterial strains. To test this, we inoculated autoclaved crude oil medium with six ...

  6. Interspecific interactions of heterotrophic bacteria during chitin degradation

    Jagmann, Nina

    2012-01-01

    In their natural habitats, bacteria live in multi-species microbial communities and are, thus, constantly interacting with bacteria of other phylogenetic groups. In order to prevail in these interspecific interactions, such as the competition for nutrients, bacteria have developed numerous strategies. During the degradation of polymers such interspecific interactions are likely to occur, because degradation starts as an extracellular process. In one possible interaction scenario, investor bac...

  7. Biological activity of a red-tide alga--A. tamarense under co-cultured condition with bacteria

    SU Jian-qiang; YU Zhi-ming; TIAN Yun; SONG Xiu-xian; HONG Hua-sheng; ZHENG Tian-ling

    2005-01-01

    The relationship between Alexandrium tamarense(Lebour) Balech, one of red-tide alga, and two strains of marine bacteria,Bacillius megaterium(S7 ) and B. halmapulus(S10) isolated from Xiamen Western Sea, was investigated by evaluating the growth state of A. tamarense and the variation of β-glucosidase activity in co-culture system. The results showed the growth and multiplication of the alga were related with the concentration, genus speciality of the bacteria, and growth stage of the alga itself. The growth of A. tamarense was obviously inhibited by S7 and S10 at high concentration. Either inhibition or promotion contributed much more clearly in earlier than in later stage of the growth of the alga. Furthermore, there was a roughly similar variation trend of the activity of extra-cellular enzyme, β-glucosidase, in the water of the separately co-cultured bacteria S7 and S10 with the alga. The β-glucosidase activity(β-GlcA) rapidly increased during the later algal growth accompanying the increase of the lysis of the alga cells. The obvious inhibition of A. tamarense by marine bacteria at high concentration and evident increase of β-GlcA in co-colture system would help us in better understanding the relationship between red-tide alga and bacteria, and also enlightened us the possible use of bacteria in the bio-control of red-tide.

  8. Can bacteria save the planet?

    Hunter, Philip

    2010-01-01

    Bacteria might just hold the key to preserving the environment for our great grandchildren. Philip Hunter explores some of the novel ways in which systems biology and biotechnology are harnessing bacteria to produce renewable energy and clean up pollution.

  9. Cable Bacteria in Freshwater Sediments

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus B.; Dittmer, Anders Lindequist; Bjerg, Jesper Tataru; Trojan, Daniela; Schreiber, Lars; Damgaard, Lars Riis; Schramm, Andreas; Nielsen, Lars Peter

    2015-01-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the fre...

  10. Manufacturing process influences properties of probiotic bacteria

    Grzeskowiak, Lukasz; Isolauri, Erika; Salminen, Seppo; Gueimonde Fernández, Miguel

    2011-01-01

    Production and manufacturing methods and the food carrier may influence the properties of probiotic strains, and have an impact on the outcome of clinical intervention studies. The aim of the present study was to establish whether the properties of a specific probiotic strain, Lactobacillus rhamnosus GG, may differ depending on the product and source of the strain. In total, fifteen different L. rhamnosus isolates, among them fourteen labelled as L. rhamnosus GG, were isolated from specific p...

  11. Manufacture of Probiotic Bacteria

    Muller, J. A.; Ross, R. P.; Fitzgerald, G. F.; Stanton, C.

    Lactic acid bacteria (LAB) have been used for many years as natural biopreservatives in fermented foods. A small group of LAB are also believed to have beneficial health effects on the host, so called probiotic bacteria. Probiotics have emerged from the niche industry from Asia into European and American markets. Functional foods are one of the fastest growing markets today, with estimated growth to 20 billion dollars worldwide by 2010 (GIA, 2008). The increasing demand for probiotics and the new food markets where probiotics are introduced, challenges the industry to produce high quantities of probiotic cultures in a viable and stable form. Dried concentrated probiotic cultures are the most convenient form for incorporation into functional foods, given the ease of storage, handling and transport, especially for shelf-stable functional products. This chapter will discuss various aspects of the challenges associated with the manufacturing of probiotic cultures.

  12. Exopolysaccharides from Marine Bacteria

    CHI Zhenming; FANG Yan

    2005-01-01

    Microbial polysaccharides represent a class of important products of growing interest for many sectors of industry. In recent years, there has been a growing interest in isolating new exopolysaccharides (EPSs)-producing bacteria from marine environments, particularly from various extreme marine environments. Many new marine microbial EPSs with novel chemical compositions, properties and structures have been found to have potential applications in fields such as adhesives,textiles, pharmaceuticals and medicine for anti-cancer, food additives, oil recovery and metal removal in mining and industrial waste treatments, etc This paper gives a brief summary of the information about the EPSs produced by marine bacteria,including their chemical compositions, properties and structures, together with their potential applications in industry.

  13. Bacteria, Phages and Septicemia

    Gaidelytė, Aušra; Vaara, Martti; Bamford, Dennis H.

    2007-01-01

    The use of phages is an attractive option to battle antibiotic resistant bacteria in certain bacterial infections, but the role of phage ecology in bacterial infections is obscure. Here we surveyed the phage ecology in septicemia, the most severe type of bacterial infection. We observed that the majority of the bacterial isolates from septicemia patients spontaneously secreted phages active against other isolates of the same bacterial strain, but not to the strain causing the disease. Such ph...

  14. Bacteria, food, and cancer

    Rooks, Michelle G.; Garrett, Wendy S.

    2011-01-01

    Gut microbes are essential components of the human organism—helping us metabolize food into energy, produce micronutrients, and shape our immune systems. Having a particular pattern of gut microbes is also increasingly being linked to medical conditions including obesity, inflammatory bowel disease, and diabetes. Recent studies now indicate that our resident intestinal bacteria may also play a critical role in determining one's risk of developing cancer, ranging from protection against cancer...

  15. Lethal Mutagenesis of Bacteria

    Bull, James J; Wilke, Claus O.

    2008-01-01

    Lethal mutagenesis, the killing of a microbial pathogen with a chemical mutagen, is a potential broad-spectrum antiviral treatment. It operates by raising the genomic mutation rate to the point that the deleterious load causes the population to decline. Its use has been limited to RNA viruses because of their high intrinsic mutation rates. Microbes with DNA genomes, which include many viruses and bacteria, have not been considered for this type of treatment because their low intrinsic mutatio...

  16. Bacteria are not Lamarckian

    Danchin, Antoine

    2007-01-01

    Instructive influence of environment on heredity has been a debated topic for centuries. Darwin's identification of natural selection coupled to chance variation as the driving force for evolution, against a formal interpretation proposed by Lamarck, convinced most scientists that environment does not specifically instruct evolution in an oriented direction. This is true for multicellular organisms. In contrast, bacteria were long thought of as prone to receive oriented influences from their ...

  17. Genetically engineered acidophilic heterotrophic bacteria by bacteriophage transduction

    Ward, T.E.; Bruhn, D.F.; Bulmer, D.F.

    1989-05-10

    A bacteriophage capable of infecting acidophilic heterotrophic bacteria and processes for genetically engineering acidophilic bacteria for biomining or sulfur removal from coal are disclosed. The bacteriophage is capable of growth in cells existing at pH at or below 3.0. Lytic forms of the phage introduced into areas experiencing acid drainage kill the bacteria causing such drainage. Lysogenic forms of the phage having genes for selective removal of metallic or nonmetallic elements can be introduced into acidophilic bacteria to effect removal of the desired element from ore or coal. 1 fig., 1 tab.

  18. Bacteria in crude oil survived autoclaving and stimulated differentially by exogenous bacteria.

    Gong, Xiao-Cui; Liu, Ze-Shen; Guo, Peng; Chi, Chang-Qiao; Chen, Jian; Wang, Xing-Biao; Tang, Yue-Qin; Wu, Xiao-Lei; Liu, Chun-Zhong

    2012-01-01

    Autoclaving of crude oil is often used to evaluate the hydrocarbon-degrading abilities of bacteria. This may be potentially useful for bioaugmentation and microbial enhanced oil recovery (MEOR). However, it is not entirely clear if "endogenous" bacteria (e.g., spores) in/on crude oil survive the autoclaving process, or influence subsequent evaluation of the hydrocarbon-degradation abilities of the "exogenous" bacterial strains. To test this, we inoculated autoclaved crude oil medium with six exogenous bacterial strains (three Dietzia strains, two Acinetobacter strains, and one Pseudomonas strain). The survival of the spore-forming Bacillus and Paenibacillus and the non-spore-forming mesophilic Pseudomonas, Dietzia, Alcaligenes, and Microbacterium was detected using a 16S rRNA gene clone library and terminal restriction fragment length polymorphism (T-RFLP) analysis. However, neither bacteria nor bacterial activity was detected in three controls consisting of non-inoculated autoclaved crude oil medium. These results suggest that detection of endogenous bacteria was stimulated by the six inoculated strains. In addition, inoculation with Acinetobacter spp. stimulated detection of Bacillus, while inoculation with Dietzia spp. and Pseudomonas sp. stimulated the detection of more Pseudomonas. In contrast, similar exogenous bacteria stimulated similar endogenous bacteria at the genus level. Based on these results, special emphasis should be applied to evaluate the influence of bacteria capable of surviving autoclaving on the hydrocarbon-degrading abilities of exogenous bacteria, in particular, with regard to bioaugmentation and MEOR. Bioaugmentation and MEOR technologies could then be developed to more accurately direct the growth of specific endogenous bacteria that may then improve the efficiency of treatment or recovery of crude oil. PMID:23028421

  19. Bacteria in crude oil survived autoclaving and stimulated differentially by exogenous bacteria.

    Xiao-Cui Gong

    Full Text Available Autoclaving of crude oil is often used to evaluate the hydrocarbon-degrading abilities of bacteria. This may be potentially useful for bioaugmentation and microbial enhanced oil recovery (MEOR. However, it is not entirely clear if "endogenous" bacteria (e.g., spores in/on crude oil survive the autoclaving process, or influence subsequent evaluation of the hydrocarbon-degradation abilities of the "exogenous" bacterial strains. To test this, we inoculated autoclaved crude oil medium with six exogenous bacterial strains (three Dietzia strains, two Acinetobacter strains, and one Pseudomonas strain. The survival of the spore-forming Bacillus and Paenibacillus and the non-spore-forming mesophilic Pseudomonas, Dietzia, Alcaligenes, and Microbacterium was detected using a 16S rRNA gene clone library and terminal restriction fragment length polymorphism (T-RFLP analysis. However, neither bacteria nor bacterial activity was detected in three controls consisting of non-inoculated autoclaved crude oil medium. These results suggest that detection of endogenous bacteria was stimulated by the six inoculated strains. In addition, inoculation with Acinetobacter spp. stimulated detection of Bacillus, while inoculation with Dietzia spp. and Pseudomonas sp. stimulated the detection of more Pseudomonas. In contrast, similar exogenous bacteria stimulated similar endogenous bacteria at the genus level. Based on these results, special emphasis should be applied to evaluate the influence of bacteria capable of surviving autoclaving on the hydrocarbon-degrading abilities of exogenous bacteria, in particular, with regard to bioaugmentation and MEOR. Bioaugmentation and MEOR technologies could then be developed to more accurately direct the growth of specific endogenous bacteria that may then improve the efficiency of treatment or recovery of crude oil.

  20. Denitrification by extremely halophilic bacteria

    Hochstein, L. I.; Tomlinson, G. A.

    1985-01-01

    Extremely halophilic bacteria were isolated from widely separated sites by anaerobic enrichment in the presence of nitrate. The anaerobic growth of several of these isolates was accompanied by the production of nitrite, nitrous oxide, and dinitrogen. These results are a direct confirmation of the existence of extremely halophilic denitrifying bacteria, and suggest that such bacteria may be common inhabitants of hypersaline environments.

  1. Magnetosome chain superstructure in uncultured magnetotactic bacteria

    Magnetotactic bacteria produce magnetosomes, which are magnetic particles enveloped by biological membranes, in a highly controlled mineralization process. Magnetosomes are used to navigate in magnetic fields by a phenomenon called magnetotaxis. Two levels of organization and control are recognized in magnetosomes. First, magnetotactic bacteria create a spatially distinct environment within vesicles defined by their membranes. In the vesicles, the bacteria control the size, composition and purity of the mineral content of the magnetic particles. Unique crystal morphologies are produced in magnetosomes as a consequence of this bacterial control. Second, magnetotactic bacteria organize the magnetosomes in chains within the cell body. It has been shown in a particular case that the chains are positioned within the cell body in specific locations defined by filamentous cytoskeleton elements. Here, we describe an additional level of organization of the magnetosome chains in uncultured magnetotactic cocci found in marine and freshwater sediments. Electron microscopy analysis of the magnetosome chains using a goniometer showed that the magnetic crystals in both types of bacteria are not oriented at random along the crystal chain. Instead, the magnetosomes have specific orientations relative to the other magnetosomes in the chain. Each crystal is rotated either 60°, 180° or 300° relative to their neighbors along the chain axis, causing the overlapping of the (1 1 1) and (1-bar 1-bar 1-bar) capping faces of neighboring crystals. We suggest that genetic determinants that are not present or active in bacteria with magnetosomes randomly rotated within a chain must be present in bacteria that organize magnetosomes so precisely. This particular organization may also be used as an indicative biosignature of magnetosomes in the study of magnetofossils in the cases where this symmetry is observed

  2. Study on Treatment of Hypersaline Dye Wastewater with Combined Process of Photosynthetic Bacteria and Activated Sludge%光合细菌/活性污泥工艺处理高盐染料废水的研究

    王慧荣; 韦彦斐; 梅荣武

    2011-01-01

    采用厌氧酸化、陶粒挂膜的光合细菌(简称PSB)和组合填料挂膜的活性污泥组合技术处理高盐染料废水,考察了其除污效果以及PSB池在流程中的位置对去除污染物的影响.结果表明:随着含盐量和COD浓度的增加,PSB/活性污泥工艺和活性污泥/PSB工艺对高盐染料废水的处理效果均下降.当含盐量为2%、COD为4 000 mg/L左右时,两工艺对COD的平均去除率分别为90.9%和85.1%,对氨氮的平均去除率分别为9.3%和9.7%,对总氮的平均去除率分别为15.5%和15.6%,脱色率分别为90.9%和89.2%.可见,PSB/活性污泥工艺对COD和色度的去除效果更好,适合处理高盐染料废水.%The hypersaline dye wastewater was treated by the combined process of anaerobic acidification, photosynthetic bacteria (PSB)immobilized on the ceransite and activated sludge immobilized on the assembled carrier.Pollutants removal and influence of position of PSB tank in the process were investigated.The results show that the treatment effect of both PSB/activated sludge and activated sludge/PSB processes is declined with the increase of COD and saline concentration in the hypersaline dye wastewater.When the saline concentration and COD are 2% and 4 000 mg/L respectively, for the two processes, the average removal rates of COD are 90.9% and 85.1% respectively, those of ammonia nitrogen are 9.3% and 9.7% respectively, those of total nitrogen are 15.5% and 15.6% respectively,and the color removal rates are 90.9% and 89.2% respectively.It is concluded that the PSB/activated sludge process has better efficiency for COD and color removal from the hypersaline dye wastewater.

  3. Olive oil glycero lysis with the immobilized lipase Candida antarctica in a solvent free system

    Singh, A. K.; Mukhopadhyay, M.

    2012-11-01

    In the present work, the solvent free lipase glycerolysis of olive oil for the production of monoglyceride (MG) and diglyceride (DG) with an immobilized Lipase B Candida antarctica was studied. The experiments were performed in batch mode by varying different process parameters. The Results showed that the MG and DG yields were dependent on operating conditions such as time, temperature, glycerol/ oil molar ratio, enzyme concentration and the water content in glycerol. The optimum operating time for maximum MG, 26 wt% and DG, 30 wt% production was 3h. The initial reaction rate was studied by varying different process parameters for 1h. The initial reaction rate increased at 30 degree centigrade temperature, 2:1 glycerol/oil molar ratio, 3.5% (w/w) water content in glycerol and 0.015g of enzyme loading. Comparative data for MG and DG yields for different oils and enzyme combinations were presented.

  4. Pepsin homologues in bacteria

    Bateman Alex

    2009-09-01

    Full Text Available Abstract Background Peptidase family A1, to which pepsin belongs, had been assumed to be restricted to eukaryotes. The tertiary structure of pepsin shows two lobes with similar folds and it has been suggested that the gene has arisen from an ancient duplication and fusion event. The only sequence similarity between the lobes is restricted to the motif around the active site aspartate and a hydrophobic-hydrophobic-Gly motif. Together, these contribute to an essential structural feature known as a psi-loop. There is one such psi-loop in each lobe, and so each lobe presents an active Asp. The human immunodeficiency virus peptidase, retropepsin, from peptidase family A2 also has a similar fold but consists of one lobe only and has to dimerize to be active. All known members of family A1 show the bilobed structure, but it is unclear if the ancestor of family A1 was similar to an A2 peptidase, or if the ancestral retropepsin was derived from a half-pepsin gene. The presence of a pepsin homologue in a prokaryote might give insights into the evolution of the pepsin family. Results Homologues of the aspartic peptidase pepsin have been found in the completed genomic sequences from seven species of bacteria. The bacterial homologues, unlike those from eukaryotes, do not possess signal peptides, and would therefore be intracellular acting at neutral pH. The bacterial homologues have Thr218 replaced by Asp, a change which in renin has been shown to confer activity at neutral pH. No pepsin homologues could be detected in any archaean genome. Conclusion The peptidase family A1 is found in some species of bacteria as well as eukaryotes. The bacterial homologues fall into two groups, one from oceanic bacteria and one from plant symbionts. The bacterial homologues are all predicted to be intracellular proteins, unlike the eukaryotic enzymes. The bacterial homologues are bilobed like pepsin, implying that if no horizontal gene transfer has occurred the duplication

  5. Nd:YAG Laser Lysis of the Fibrinous Membrane and Remnant Substance on the Anterior Surface of Intraocular Lens

    ZhendeLin; ChenjinJin

    1995-01-01

    Purpose:To determine the effects of ND:YAGlaser to disrupt the fibrinous membrane and remnant substance on the anterior surface of intraocular lens.Methods:Nd:YAGlaser was applied on 23cases of fibrinous membrane forma-tion and 8cases of remnant substance on the anterior surface of intaocular lenses(IOL)which had not reponded well to steroid therapy,Eighteen cases were male and 13female.The mean age was49.7years(range,5-78years),The in-terval between IOL implantation and laser therapy was 0.5-30months in the fibrinous membrane cases and 3-10days in the remnant substance cases.The energy applied was0.8-3.0mJ/exp.with2-112exposures.mean follow-up period was3.6months.Results:Complications during therapy included only 2cases of slight iris bleed-ing,Visual acuity after therapy was improved 1line in 16cases,2lines in 11cas-es,3lines in 1case,4lines in 1case and 5lines in 2cases,No post-therapy com-plication was found.Conclusions:Nd:YAG laser lysis is an effective alternative to ramove the fibri-nous membrane and remnant substances on the anterior surface of IOL.Eye Sci-ence1995;11:128-130.

  6. Rifaximin Does Not Induce Toxin Production or Phage-Mediated Lysis of Shiga Toxin-Producing Escherichia coli▿

    Ochoa, Theresa J.; Chen, Jane; Walker, Christopher M.; Gonzales, Elsa; Cleary, Thomas G.

    2007-01-01

    Diarrhea in children is often caused by enteropathogen infections that might benefit from early empirical antibiotic therapy. However, when the definition of the pathogen requires sophisticated laboratory studies, the etiology of enteritis is not known early in illness. Empirical therapy may be dangerous if the child is infected with a Shiga toxin-producing Escherichia coli (STEC) strain because antimicrobials may increase Shiga toxin (Stx) release, resulting in increased risk of microangiopathic hemolytic anemia with acute renal failure (hemolytic-uremic syndrome [HUS]) and death. There is a need for antimicrobials that would be effective against multiple bacterial enteropathogens yet not induce Stx release or increase the risk of HUS. Rifaximin has been evaluated in adults for treatment of bacterial enteritis and has a good record for safety and efficacy, but it has not been evaluated extensively in children with gastroenteritis. We therefore evaluated rifaximin's potential for phage induction, drug-induced bacteriolysis, and toxin release in 57 STEC strains (26 O157 and 31 non-O157 strains). Growth in ciprofloxacin, a known Stx phage inducer, caused bacteriolysis and release of toxin in 25/26 (96%) O157 strains and 15/31 (48%) non-O157 strains. In contrast, rifaximin did not induce phage replication or lysis in any strain. Toxin release in the presence of rifaximin was not different from release in the absence of antibiotic. Rifaximin, unlike many antibiotics used to treat pediatric gastroenteritis, does not induce phage-mediated bacteriolysis and Stx release. PMID:17526759

  7. Lysis of dysplastic but not normal oral keratinocytes and tissue-engineered epithelia with conditionally replicating adenoviruses.

    Gaballah, Kamis; Hills, Allison; Curiel, David; Hallden, Gunnel; Harrison, Paul; Partridge, Max

    2007-08-01

    There is no effective medical treatment for oral precancer, and surgery to remove these lesions is imprecise because abnormal mucosa extends beyond the visible lesion. Development of vectors for tumor-selective viral replication has been a significant advance, and viral lysis is well suited to destruction of oral precancerous mucosa. To facilitate evaluation of new treatments, we engineered dysplastic oral epithelium using keratinocytes isolated from dysplastic lesions. We show that these model systems recapitulate the key characteristics of the clinical lesions closely, and that topical delivery of the conditionally replicating adenovirus (CRAd) dl922-947 can lyse tissue-engineered epithelia that show mild, moderate, or severe dysplasia, but normal oral epithelia are very resistant to this treatment. The lytic effect is determined by various factors, including the grade and proliferation index of the dysplastic epithelia. The presence of suprabasal cycling cells, expression of the coxsackie adenovirus receptor (CAR), the transcription cofactor p300, and other aberrations that affect the regulation of the cell cycle or apoptosis and promote viral replication may also be important. The ability of dl922-947 to destroy engineered oral dysplasia was significantly greater than that observed using wild-type adenovirus, d/1520, or viruses modified to bypass cell entry dependent on the presence of CAR. Evidence of infection in clinical dysplastic lesions was also shown ex vivo using tissue explants. We conclude that dl922-947 may provide an efficient molecular cytotoxic to dissolve oral dysplastic lesions. PMID:17671197

  8. Granulocytes of sea anemone Actinia equina (Linnaeus, 1758 body fluid contain and release cytolysins forming plaques of lysis

    MG Parisi

    2014-01-01

    Full Text Available The Cnidaria phylum includes organisms that are among the most poisonous animals. The exact composition of cnidarian bioactive molecules is not known in detail, but little is known on the cells that produce the toxins. Here we have shown that the presence of cytolysins is not exclusive of nematocysts. A plaque-forming assay was carried out with cell populations extracted from the percoled body fluid showed for the first time that anthozoan granulocytes are able to form plaque of lysis. We have partitioned the total population of free cells into three distinct discrete bands by discontinuous Percoll gradient, and we have identified six small different types cells: morular granulocytes; cells with large or small peripherical granules, granulocytes with irregular shape containing blue and red granules, cells showing one fine red granule of uniform size and, finally, cells with elongated shape and small dispersed granules. Cell lysate of each cellular band resulted cytolytic toward different erythrocytes types. SDS page analysis of the lysate cell fraction showed a predominant of 20 kDa that corresponds to the weight of the cytolytic equinatoxin. The nature of equinatoxins-related activity was demonstrated by inhibition experiments using bovine sphingomyelin.

  9. Efficiency of Heterotrophic Nitrification Bacteria in Biologically Enhanced Activated Carbon Process for Treatment of Low Temperature Water%异养硝化菌生物增强活性炭处理低温水的效能

    秦雯; 李伟光; 张多英; 黄晓飞

    2013-01-01

    Biologically enhanced activated carbon (BEAC) filter columns were constructed to research the efficiency of heterotrophic nitrification bacteria Y7 and Y16 for treating low temperature water.The filter columns A,B and C were inoculated with Y7 strains,Y16 strains and Y7 + Y16 mixed bacteria,respectively,the filter column D was not inoculated as a control.The removal of NH4+-N and CODMn,the accumulation of NO2--N and NO3--N and the influence of different dissolved oxygen (DO) concentrations and filter speeds on the BEAC process were investigated at temperature of 5 ℃.The results showed that BEAC process was better than GAC process in NH4+-N removal,and the filter column C had the best removal efficiency of NH4+-N.The accumulation of NO2--N and NO3--N did not occur,and the maximum removal rates of NH4+-N and CODMn in the filter column C were 26.88% and 85.12%,respectively.Influent DO concentration had little impact on NH4+-N and CODMn removal in each filter column.Low filter speed was favorable for degradation of NH4+-N by BEAC,but not for removal of CODMn.%为研究异养硝化菌Y7和Y16对低温水的处理效果,构建生物增强活性炭(BEAC)滤柱,其中A滤柱接种Y7菌株,B滤柱接种Y16菌株,C滤柱接种Y7+ Y16混菌,以不接菌活性炭滤柱(D)作为对照.在5℃下研究了工艺对氨氮和CODMn的去除效果、亚硝酸盐氮与硝酸盐氮的积累特征以及进水DO含量和滤速对BEAC工艺运行效果的影响.结果表明,BEAC工艺对氨氮的去除效果优于GAC,其中C滤柱对氨氮的降解能力最强,运行期间并未出现硝酸盐氮与亚硝酸盐氮积累现象,启动期间对氨氮的最大去除率达到26.88%,对CODMn的最大去除率达到85.12%.进水溶解氧浓度对各滤柱去除氨氮和CODMn几乎没有影响;低滤速有利于BEAC对氨氮的降解,但对去除CODMn的影响较小.

  10. Bacteria counting method based on polyaniline/bacteria thin film.

    Zhihua, Li; Xuetao, Hu; Jiyong, Shi; Xiaobo, Zou; Xiaowei, Huang; Xucheng, Zhou; Tahir, Haroon Elrasheid; Holmes, Mel; Povey, Malcolm

    2016-07-15

    A simple and rapid bacteria counting method based on polyaniline (PANI)/bacteria thin film was proposed. Since the negative effects of immobilized bacteria on the deposition of PANI on glass carbon electrode (GCE), PANI/bacteria thin films containing decreased amount of PANI would be obtained when increasing the bacteria concentration. The prepared PANI/bacteria film was characterized with cyclic voltammetry (CV) technique to provide quantitative index for the determination of the bacteria count, and electrochemical impedance spectroscopy (EIS) was also performed to further investigate the difference in the PANI/bacteria films. Good linear relationship of the peak currents of the CVs and the log total count of bacteria (Bacillus subtilis) could be established using the equation Y=-30.413X+272.560 (R(2)=0.982) over the range of 5.3×10(4) to 5.3×10(8)CFUmL(-1), which also showed acceptable stability, reproducibility and switchable ability. The proposed method was feasible for simple and rapid counting of bacteria. PMID:26921555

  11. Micropipette manipulation technique for the monitoring of pH-dependent membrane lysis as induced by the fusion peptide of influenza virus.

    Soltesz, S A; Hammer, D A

    1995-01-01

    We have assembled a micropipette aspiration assay to measure membrane destabilization events in which large (20-30 microns diameter) unilamellar vesicles are manipulated and exposed to membrane destabilizing agents. Single events can be seen with a light microscope and are recorded using both a video camera and a photomultiplier tube. We have performed experiments with a wild-type fusion peptide from influenza virus (X31) and found that it induces pH-dependent, stochastic lysis of large unila...

  12. Mechanism of Action of Melaleuca alternifolia (Tea Tree) Oil on Staphylococcus aureus Determined by Time-Kill, Lysis, Leakage, and Salt Tolerance Assays and Electron Microscopy

    Carson, Christine F.; Mee, Brian J.; Riley, Thomas V.

    2002-01-01

    The essential oil of Melaleuca alternifolia (tea tree) has broad-spectrum antimicrobial activity. The mechanisms of action of tea tree oil and three of its components, 1,8-cineole, terpinen-4-ol, and α-terpineol, against Staphylococcus aureus ATCC 9144 were investigated. Treatment with these agents at their MICs and two times their MICs, particularly treatment with terpinen-4-ol and α-terpineol, reduced the viability of S. aureus. None of the agents caused lysis, as determined by measurement ...

  13. Lysis of uninfected and virus-infected cells in vivo: a rejection mechanism in addition to that mediated by natural killer cells.

    Biron, C. A.; Habu, S.; Okumura, K.; Welsh, R. M.

    1984-01-01

    To examine the lysis of virus-infected cells in vivo, uninfected and lymphocytic choriomeningitis virus (LCMV)-infected L-929 cells were labeled in vitro with [125I]-iododeoxyuridine and implanted intravenously into mice. Natural cytotoxicity against both uninfected and virus-infected cells was demonstrated in normal uninfected mice, but LCMV-infected cells were cleared from the lungs and whole bodies more rapidly than uninfected cells. Treatment of L-929 cells with defective interfering LCMV...

  14. Rasburicase in the prevention of laboratory/clinical tumour lysis syndrome in children with advanced mature B-NHL: A Children’s Oncology Group Report

    Galardy, Paul; Hochberg, Jessica; Perkins, Sherrie L.; Harrison, Lauren; Goldman, Stanton; Cairo, Mitchell S

    2013-01-01

    Laboratory (LTLS) and clinical (CTLS) tumour lysis syndrome (TLS) are frequent complications in newly diagnosed children with advanced mature B cell non-Hodgkin lymphoma (B-NHL). Rasburicase, compared to allopurinol, results in more rapid reduction of uric acid in paediatric patients at risk for TLS. However, the safety and efficacy of rasburicase for the treatment or or prevention of TLS has not been prospectively evaluated. Children with newly diagnosed stage III–IV, bone marrow+ and/or cen...

  15. Using Mathematical Modelling to Explore Hypotheses about the Role of Bovine Epithelium Structure in Foot-And-Mouth Disease Virus-Induced Cell Lysis

    Kyriaki Giorgakoudi; Simon Gubbins; John Ward; Nicholas Juleff; Zhidong Zhang; David Schley

    2015-01-01

    Foot-and-mouth disease (FMD) is a highly contagious disease of cloven-hoofed animals. FMD virus (FMDV) shows a strong tropism for epithelial cells, and FMD is characterised by cell lysis and the development of vesicular lesions in certain epithelial tissues (for example, the tongue). By contrast, other epithelial tissues do not develop lesions, despite being sites of viral replication (for example, the dorsal soft palate). The reasons for this difference are poorly understood, but hypotheses ...

  16. Combined Transfection with EBV-Specific Epitopes and HLA-A2 genes is More Effective than Separate Transfection in Promoting CTL Lysis against Nasopharyngeal Carcinoma

    Weijun Ding; Choylen Fong

    2004-01-01

    To augment specific cytotoxic T lymphocyte (CTL) lysis is a promising strategy for cancer therapy. In this study,we examined the boosting effect of CTLs upon autologous lymphoblastoid B cell lines (LCLs) transfected with diverse plasmids, to explore the possible CTL-based immunotherapy of nasopharyngeal carcinoma (NPC).FCM analysis displayed rather high ratio (>30%) of successfully transfected LCLs by utilizing the DMRIE-C kit. CTL assays demonstrated that substantially higher ratio of CTL specific lysis was observed upon the LCLs transfected with both expression vectors encoding EBV-specific epitopes and their presentation molecule HLA-A2, in contrast with those transfected separately. By transfecting the vector encoding HLA-A2 alone, only the LCLs of HLA-A2+ donors elicited markedly higher CTL lysis. CTL assays also showed that there existed no marked differences upon transfection by either different vectors (pcDNA3, pNGVL3 or pNGVL3-hFlex), or different EBV-derived peptides (LMP2Pep1 or LMP2Pep2), or with or without the doubled DNA sequence encoding peptides. This study indicated a promising immunotherapy strategy on NPC through boosting and eliciting the EBV-specific CTL activation by transferring vectors encoding both EBV-specific epitopes and their presentation molecule HLA-A2 into autologous LCL, the presentation cells of MHC/peptide tetrameric complex.

  17. Combined Transfection with EBV-Specific Epitopes and HLA-A2 genes is More Effective than Separate Transfection in Promoting CTL Lysis against Nasopharyngeal Carcinoma

    WeijunDing; ChoylenFong

    2004-01-01

    To augment specific cytotoxic T lymphocyte (CTL) lysis is a promising strategy for cancer therapy. In this study,we examined the boosting effect of CTLs upon autologous lymphoblastoid B cell lines (LCLs) transfected with diverse plasmids, to explore the possible CTL-based immunotherapy of nasopharyngeal carcinoma (NPC).FCM analysis displayed rather high ratio (>30%) of successfully transfected LCLs by utilizing the DMRIE-C kit. CTL assays demonstrated that substantially higher ratio of CTL specific lysis was observed upon the LCLs transfected with both expression vectors encoding EBV-specific epitopes and their presentation molecule HLA-A2, In contrast with those transfected separately. By transfecting the vector encoding HLA-A2 alone, only the LCLs of HLA-A2+ donors elicited markedly higher CTL lysis. CTL assays also showed that there existed no marked differences upon transfection by either different vectors (pcDNA3, pNGVL3 or pNGVL3-hFIex), or different EBV-derived peptides (LMP2Pep1 or LMP2Pep2), or with or without the doubled DNA sequence encoding peptides. This study indicated a promising immunotherapy strategy on NPC through boosting and eliciting the EBV-specific CTL activation by transferring vectors encoding both EBV-specific epitopes and their presentation molecule HLA-A2 into autologous LCL, the presentation cells of MHC/peptide tetrameric complex.

  18. Small molecule ice recrystallization inhibitors mitigate red blood cell lysis during freezing, transient warming and thawing

    Briard, Jennie G.; Poisson, Jessica S.; Turner, Tracey R.; Capicciotti, Chantelle J.; Acker, Jason P.; Ben, Robert N.

    2016-03-01

    During cryopreservation, ice recrystallization is a major cause of cellular damage. Conventional cryoprotectants such as dimethyl sulfoxide (DMSO) and glycerol function by a number of different mechanisms but do not mitigate or control ice recrystallization at concentrations utilized in cryopreservation procedures. In North America, cryopreservation of human red blood cells (RBCs) utilizes high concentrations of glycerol. RBC units frozen under these conditions must be subjected to a time-consuming deglycerolization process after thawing in order to remove the glycerol to <1% prior to transfusion thus limiting the use of frozen RBC units in emergency situations. We have identified several low molecular mass ice recrystallization inhibitors (IRIs) that are effective cryoprotectants for human RBCs, resulting in 70–80% intact RBCs using only 15% glycerol and slow freezing rates. These compounds are capable of reducing the average ice crystal size of extracellular ice relative to a 15% glycerol control validating the positive correlation between a reduction in ice crystal size and increased post-thaw recovery of RBCs. The most potent IRI from this study is also capable of protecting frozen RBCs against the large temperature fluctuations associated with transient warming.

  19. Collective Sensing-Capacity of Bacteria Populations

    Einolghozati, Arash; Fekri, Faramarz

    2012-01-01

    The design of biological networks using bacteria as the basic elements of the network is initially motivated by a phenomenon called quorum sensing. Through quorum sensing, each bacterium performs sensing the medium and communicating it to others via molecular communication. As a result, bacteria can orchestrate and act collectively and perform tasks impossible otherwise. In this paper, we consider a population of bacteria as a single node in a network. In our version of biological communication networks, such a node would communicate with one another via molecular signals. As a first step toward such networks, this paper focuses on the study of the transfer of information to the population (i.e., the node) by stimulating it with a concentration of special type of a molecules signal. These molecules trigger a chain of processes inside each bacteria that results in a final output in the form of light or fluorescence. Each stage in the process adds noise to the signal carried to the next stage. Our objective is ...

  20. Beneficial bacteria inhibit cachexia.

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

    2016-03-15

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

  1. Lactic Acid Bacteria

    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.

  2. Involvement of penicillin-binding protein 2 with other penicillin-binding proteins in lysis of Escherichia coli by some beta-lactam antibiotics alone and in synergistic lytic effect of amdinocillin (mecillinam).

    Gutmann, L; Vincent, S; Billot-Klein, D; Acar, J F; Mrèna, E; Williamson, R.

    1986-01-01

    Compared with cefotaxime, ceftazidime, moxalactam, and aztreonam, ceftriaxone produced the best lytic and bactericidal effects when each was added at about 10 times the MIC to Escherichia coli W7. When each of these antibiotics was added at its MIC, only bacteriostasis occurred, but the simultaneous addition of amdinocillin (mecillinam) was synergistic in causing rapid lysis and bactericidal effects. Induction of lysis of two E. coli mutants containing either a thermosensitive penicillin-bind...

  3. Nitrogen acquisition in Agave tequilana from degradation of endophytic bacteria.

    Beltran-Garcia, Miguel J; White, James F; Prado, Fernanda M; Prieto, Katia R; Yamaguchi, Lydia F; Torres, Monica S; Kato, Massuo J; Medeiros, Marisa H G; Di Mascio, Paolo

    2014-01-01

    Plants form symbiotic associations with endophytic bacteria within tissues of leaves, stems, and roots. It is unclear whether or how plants obtain nitrogen from these endophytic bacteria. Here we present evidence showing nitrogen flow from endophytic bacteria to plants in a process that appears to involve oxidative degradation of bacteria. In our experiments we employed Agave tequilana and its seed-transmitted endophyte Bacillus tequilensis to elucidate organic nitrogen transfer from (15)N-labeled bacteria to plants. Bacillus tequilensis cells grown in a minimal medium with (15)NH4Cl as the nitrogen source were watered onto plants growing in sand. We traced incorporation of (15)N into tryptophan, deoxynucleosides and pheophytin derived from chlorophyll a. Probes for hydrogen peroxide show its presence during degradation of bacteria in plant tissues, supporting involvement of reactive oxygen in the degradation process. In another experiment to assess nitrogen absorbed as a result of endophytic colonization of plants we demonstrated that endophytic bacteria potentially transfer more nitrogen to plants and stimulate greater biomass in plants than heat-killed bacteria that do not colonize plants but instead degrade in the soil. Findings presented here support the hypothesis that some plants under nutrient limitation may degrade and obtain nitrogen from endophytic microbes. PMID:25374146

  4. Hyperuricemia and tumor lysis syndrome in children with non-Hodgkin’s lymphoma and acute lymphoblastic leukemia

    Betül Sevinir

    2011-03-01

    Full Text Available Objective: This study aimed to examine the incidence, clinical characteristics, and outcome of hyperuricemia and tumor lysis syndrome (TLS in children with non-Hodgkin’s lymphoma (NHL and acute lymphoblastic leukemia (ALL.Materials and Methods: This retrospective study included data from 327 patients (113 NHL and 214 ALL.Results: Hyperuricemia occurred in 26.5% and 12.6% of the patients with NHL and ALL, respectively. The corresponding figures for TLS were 15.9% and 0.47% (p=0.001. All hyperuricemic NHL patients had advanced disease and renal involvement was present in 53%. All hyperuricemic ALL patients had a leukocyte count >50,000 mm3 at the time of diagnosis. Among the hyperuricemic NHL and ALL patients, 96.6% and 66.6% had LDH ≥500 UI/L, respectively. Treatment consisted of hydration and allopurinol; none of the patients received urate oxidase. Among the patients that developed TLS, 26.3% had laboratory TLS, 42.1% had grade I or II TLS, and 31.6% had grade III or IV TLS. Uric acid levels returned to normal after a mean period of 3.5±2.5 and 3.05±0.8 d in NHL and ALL groups, respectively. In all, 7% of the patients with hyperuricemia required hemodialysis. None of the patients died.Conclusion: In this series the factors associated with a high-risk for TLS were renal involvement in NHL and high leucocyte count in ALL. Management with allopurinol and hydration was effective in this group of patients with high tumor burden.

  5. Tumor lysis syndrome in the era of novel and targeted agents in patients with hematologic malignancies: a systematic review.

    Howard, Scott C; Trifilio, Steven; Gregory, Tara K; Baxter, Nadine; McBride, Ali

    2016-03-01

    Effective new treatments are now available for patients with hematologic malignancies. However, their propensity to cause tumor lysis syndrome (TLS) has not been systematically examined. A literature search identified published Phase I-III clinical trials of monoclonal antibodies (otlertuzumab, brentuximab, obinutuzumab, ibritumomab, ofatumumab); tyrosine kinase inhibitors (alvocidib [flavopiridol], dinaciclib, ibrutinib, nilotinib, dasatinib, idelalisib, venetoclax [ABT-199]); proteasome inhibitors (oprozomib, carfilzomib); chimeric antigen receptor (CAR) T cells; and the proapoptotic agent lenalidomide. Abstracts from major congresses were also reviewed. Idelalisib and ofatumumab had no reported TLS. TLS incidence was ≤5 % with brentuximab vedotin (for anaplastic large-cell lymphoma), carfilzomib and lenalidomide (for multiple myeloma), dasatinib (for acute lymphoblastic leukemia), and oprozomib (for various hematologic malignancies). TLS incidences were 8.3 and 8.9 % in two trials of venetoclax (for chronic lymphocytic leukemia [CLL]) and 10 % in trials of CAR T cells (for B-cell malignancies) and obinutuzumab (for non-Hodgkin lymphoma). TLS rates of 15 % with dinaciclib and 42 and 53 % with alvocidib (with sequential cytarabine and mitoxantrone) were seen in trials of acute leukemias. TLS mitigation was employed routinely in clinical trials of alvocidib and lenalidomide. However, TLS mitigation strategies were not mentioned or stated only in general terms for many studies of other agents. The risk of TLS persists in the current era of novel and targeted therapy for hematologic malignancies and was seen to some extent with most agents. Our findings underscore the importance of continued awareness, risk assessment, and prevention to reduce this serious potential complication of effective anticancer therapy. PMID:26758269

  6. Effects of hydrologic, biological, and environmental processes on sources and concentrations of fecal bacteria in the Cuyahoga River, with implications for management of recreational waters in Summit and Cuyahoga Counties, Ohio

    Myers, D.N.; Koltun, G.F.; Francy, D.S.

    1998-01-01

    Discharges of fecal bacteria (fecal coliform bacteria and Escherichia coli ) to the middle main stem of the Cuyahoga River from storm water, combined sewers, and incompletely disinfected wastewater have resulted in frequent exceedances of bacteriological water-quality standards in a 23-mile reach of the river that flows through the Cuyahoga Valley National Recreation Area. Contamination of the middle main stem of the Cuyahoga River by bacteria of fecal origin and subsequent transport to downstream areas where water-contact recreation is an important use of the river are a concern because of the potential public-health risk from the presence of enteric pathogens. Independent field investigations of bacterial decay, dilution, dispersion, transport, and sources, and bacterial contamination of streambed sediments, were completed in 1991-93 during periods of rainfall and runoff. The highest concentration of fecal coliform bacteria observed in the middle main stem during three transport studies exceeded the single-sample fecal coliform standard applicable to primary-contact recreation by a factor of approximately 1,300 and exceeded the Escherichia coli standard by a factor of approximately 8,000. The geometric-mean concentrations of fecal bacteria in the middle main stem were 6.7 to 12.3 times higher than geometric-mean concentrations in the monitored tributaries, and 1.8 to 7.0 times larger than the geometric-mean concentrations discharged from the Akron Water Pollution Control Station. Decay rates of fecal bacteria measured in field studies in 1992 ranged from 0.0018 per hour to 0.0372 per hour for fecal coliform bacteria and from 0.0022 per hour to 0.0407 per hour for Escherichia coli. Most of the decay rates measured in June and August were significantly higher than decay rates measured in April and October. Results of field studies demonstrated that concentrations of fecal coliform bacteria were 1.2 to 58 times higher in streambed sediments than in the overlying

  7. Cable Bacteria in Freshwater Sediments

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus;

    2015-01-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable...... bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures and...... marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary...

  8. Immunomodulatory properties of probiotic bacteria

    Fink, Lisbeth Nielsen

    2007-01-01

    Certain lactic acid bacteria (LAB) are part of the commensal intestinal flora and considered beneficial for health, as they compete with pathogens for adhesion sites in the intestine and ferment otherwise indigestible compounds. Another important property of these so-called probiotic bacteria is...... cytokines when stimulated with bacteria, and the cytokine pattern induced by specific bacteria resembled the pattern induced in MoDC, except for TNF-alpha and IL-6, which were induced in response to different bacteria in blood DC/monocytes and monocyte-derived DC. Autologous NK cells produced IFN-gamma when...... cultured with blood DC, monocytes and monocyte-derived DC and IL-12-inducing bacteria, whereas only DC induced IFN-gamma production in allogeneic T cells. In vitro-generated DC is a commonly used model of tissue DC, but they differ in certain aspects from intestinal DC, which are in direct contact with the...

  9. Síndrome de lise tumoral: uma revisão abrangente da literatura Acute tumor lysis syndrome: a comprehensive review

    Michael Darmon

    2008-09-01

    égias baseadas no risco dos pacientes são necessários para limitar a alta morbidade e mortalidade desta complicação.Tumor lysis syndrome is characterized by the massive destruction of malignant cells and the release in the extra-cellular space of their content. While Tumor lysis syndrome may occur spontaneously before treatment, it usually develops shortly after the initiation of cytotoxic chemotherapy. These metabolites can overwhelm the homeostatic mechanisms with development of hyperuricaemia, hyperkalaemia, hyperphosphataemia, and hypocalcaemia. These biological manifestations may lead to clinical manifestations including, acute kidney injury, seizure, or sudden death that require intensive care. Since clinical tumor lysis syndrome is associated with a poor prognosis both prevention of tumor lysis syndrome and prevention of clinical consequences of tumor lysis syndrome are mandatory. The objective of this review is to describe pathophysiological mechanisms, biological and clinical manifestations of tumor Lysis syndrome, and to provide upto-date guidelines to ensure prevention of tumor lysis syndrome. Review of selected studies on tumor lysis syndrome published at the PubMed database www.pubmed.gov during the last 20 years. Additional references were retrieved from the studies initially selected. Tumor lysis syndrome is a frequent and life-threatening complication of the newly diagnosed malignancies. Preventive measures, including hydration, uricolytic agents, eviction of factors predisposing to acute kidney injury and, in the more severe patients, on prophylactic renal replacement therapy, are required to prevent or limit clinical consequences of Tumor lysis syndrome. However optimal timing and modalities of prevention remains unknown and may be modified by the changing spectrum of patients at risk of tumor lysis syndrome. Development and validation of risk based strategies is required to limit the high morbidity and mortality of this complication.

  10. 山西老陈醋发酵过程菌群微生态分析及乳酸菌分离%Analysis of Microbial Community Microecology in Shanxi Aged Vinegar Fermentation Process and Isolation of Lactic Acid Bacteria

    王梦颖; 赵国忠; 赵建新; 张灏; 陈卫

    2016-01-01

    Shanxi aged vinegar is one of Chinese four famous vinegars,with unique flavor,long history and being beneficial to human health,in order to promote the development of Shanxi aged vinegar industry and prevent corruption caused by microorganisms,16S rDNA metagenomics sequencing is used to analyze the microecology of microbial community during the fermentation process of Shanxi aged vinegar,to make bacterial species and the relative abundance of them clearly,which plays a leading role during the fermentation process of Shanxi aged vinegar.Based on the study mentioned above,lactic acid bacteria are isolated and identified,in order to excavate potential microorganism resources in traditional fermented food.%山西老陈醋作为中国四大名醋之一,风味独特,历史悠久,且对人体健康有较好的促进作用。为了促进山西老陈醋发酵工业的发展及对其生产中出现的不可控微生物腐败造成的质量问题进行预防,研究采用16S rDNA 宏基因组的测序手段对山西老陈醋发酵过程中的菌群微生态进行分析,了解陈醋在酒精发酵及醋酸发酵两个重要过程中起主导作用的细菌种类及各种属微生物的相对丰度,并在对主要发酵微生物有一定了解的基础上对其中的乳酸菌进行分离、鉴定,充分挖掘传统发酵食品中具有潜力的微生物资源。

  11. Interactions between Diatoms and Bacteria

    Amin, Shady A.; Parker, Micaela S.; Armbrust, E. Virginia

    2012-01-01

    Summary: Diatoms and bacteria have cooccurred in common habitats for hundreds of millions of years, thus fostering specific associations and interactions with global biogeochemical consequences. Diatoms are responsible for one-fifth of the photosynthesis on Earth, while bacteria remineralize a large portion of this fixed carbon in the oceans. Through their coexistence, diatoms and bacteria cycle nutrients between oxidized and reduced states, impacting bioavailability and ultimately feeding hi...

  12. Radiation-resistant asporogenic bacteria

    This paper reports the biological and ecological examinations on the radiation-resistant asporogenic bacteria (mainly concerning Micrococcus radiodurans). Radiation-resistant asporogenic bacteria were isolated from the irradiated areas of the natural world as well as from the general areas and from the Rn waters in the Misasa hot spring. The acquiring of the tolerance to radiation in bacteria was also examined. In addition, the future problems of microbiological treatment with irradiation were mentioned. (Tsukamoto, Y.)

  13. Bacteria, phages and septicemia.

    Ausra Gaidelyte

    Full Text Available The use of phages is an attractive option to battle antibiotic resistant bacteria in certain bacterial infections, but the role of phage ecology in bacterial infections is obscure. Here we surveyed the phage ecology in septicemia, the most severe type of bacterial infection. We observed that the majority of the bacterial isolates from septicemia patients spontaneously secreted phages active against other isolates of the same bacterial strain, but not to the strain causing the disease. Such phages were also detected in the initial blood cultures, indicating that phages are circulating in the blood at the onset of sepsis. The fact that most of the septicemic bacterial isolates carry functional prophages suggests an active role of phages in bacterial infections. Apparently, prophages present in sepsis-causing bacterial clones play a role in clonal selection during bacterial invasion.

  14. Bacteriophages of methanotrophic bacteria

    Tyutikow, F.M. (All-Union Research Inst. for Genetics and Selection of Industrial Microorganisms, Moscow, USSR); Bespalova, I.A.; Rebentish, B.A.; Aleksandrushkina, N.N.; Krivisky, A.S.

    1980-10-01

    Bacteriophages of methanotrophic bacteria have been found in 16 out of 88 studied samples (underground waters, pond water, soil, gas and oil installation waters, fermentor cultural fluids, bacterial paste, and rumen of cattle) taken in different geographic zones of the Soviet Union. Altogether, 23 phage strains were isolated. By fine structure, the phages were divided into two types (with very short or long noncontractile tails); by host range and serological properties, they fell into three types. All phages had guanine- and cytosine-rich double-stranded deoxyribonucleic acid consisting of common nitrogen bases. By all of the above-mentioned properties, all phages within each of the groups were completely identical to one another, but differed from phages of other groups.

  15. 乳酸菌发酵技术脱除大米粉中镉的工艺优化%Optimization of fermentation process of removal of cadmium in rice powder using lactic acid bacteria

    傅亚平; 廖卢艳; 刘阳; 吴卫国

    2015-01-01

    In recent years, along with our country cadmium pollution in rice is increasingly serious, the safety and quality of rice in China has been under serious threat. Contamination of rice with cadmium also draws great attention because of its serious threat to food safety and its potential harm to human health. Thus, it’s very important and necessary for food industry to find a method to decrease the degree of cadmium pollution in polished rice. Cadmium in rice has been demonstrated that it mainly bonded with protein and little cadmium accumulated in starch and other nutritional ingredients. And processing of soaking, heating, washing can reduce the content of cadmium in rice powder, but the effect of cadmium removal is not obvious. Hence, it also was proved that the amount of heavy metals in rice dropped significantly after fermentation using lactic acid bacteria. Therefore, in order to resolve the problem of“excessive cadmium”polished rice utilization, this paper tried to reduce the content of cadmium in“excessive cadmium”polished rice(cadmium content of 0.6479mg/kg) by lactic acid bacteria and produce safe fermented rice products, and the fermentation conditions were studied and optimized. The mixed strains of Lactobacillus plantarum and Pediococcus pentosaceus(2:1,v/v) were selected as the suitable fermentation strain by comparative test. The effects of rice powder size, fermentation time, fermentation temperature and inoculum size of mixed strains on the removal rate of cadmium in polished rice also were evaluated by single-factor experiment. The results showed that fermentation time, fermentation temperature and inoculum size of mixed strains could significantly affect the removal rate of cadmium(P0.05). Then, fermentation time, fermentation temperature and inoculum size of mixed strains were further researched using a three-variable, three level Box-Benhnken design to optimize the fermentation conditions. The results indicated that the interaction

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

    Glisina Dwinoor Rembulan; Titi Candra Sunarti; Anja Meryandini

    2015-01-01

    Lactic acid bacteria (LAB) produce organic acids and active compounds which can inhibit the growth of pathogenic bacteria. Lactic acid bacteria potentially can be introduced to inhibit pathogenic bacteria in the tapioca production at the extraction stage, especially during the settling process since there is possibility of starch slurry to be contaminated by pathogenic bacteria from water. The objectives of this research were to design a solid starter of LAB through encapsulation by using mod...

  17. Populations of Fungi and Bacteria Associated with Samples of Stored Rice in Korea

    Oh, Ji Yeon; Jee, Sam Nyu; Nam, Youngwoo; Lee, Hojoung; Ryoo, Mun Il; Kim, Ki Deok

    2007-01-01

    Stored rice was collected from rice processing complexes of National Agricultural Cooperative Federation of 11 regions in Korea to evaluate the occurrence of fungi and bacteria and to identify the predominant fungi and bacteria to the genus levels. Most rice samples generally produced the higher levels of fungi and bacteria than white rice. The occurrence of fungi and bacteria varied in various locations of Korea. Among fungi observed, Aspergillus spp. and Penicillium spp. were dominant in th...

  18. Freeze-drying of lactic acid bacteria.

    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

  19. H2 from hot bacteria

    This paper reports that a surprisingly large number of bacteria either oxidize or evolve molecular hydrogen (H2) in their natural environments. In such organisms, the reversible activation of H2 is catalyzed by an enzyme turned hydrogenase that can cause electrons provided by an electron donor with protons to evolve H2. The enzyme may oxidize H2 in the presence of a suitable electron acceptor. Hydrogenase will also catalyze an isotope exchange reaction between deuterium (D2) or tritium (T2) gas and water. Few enzymes have as many potential biotechnological applications as hydrogenase. H2 is a versatile and efficient energy carrier, considered the fuel of the future by some, and is an important intermediate in a variety of chemical and petrochemical processes. Hydrogenase has also been proposed to replace platinum in H/D and H/T separations in the nuclear power industry and to activate H2 for electrode-based processes. Indeed, H2 is considered one of the most abundant substrates for the future chemical synthesis industry and the enzyme-catalyzed production of organic chemicals from H2 and CO2 has been described. a complete understanding of how hydrogenases catalyze the reversible activation of H2 might therefore have farreaching consequences in both applied and basic research

  20. Experimental evolution with bacteria in complex environments

    Hall, Alex R.

    2009-01-01

    Experiments with microbes are a powerful tool for addressing general questions in evolutionary ecology. Microbial evolution is also interesting in its own right, and often clinically relevant. I have used experimental evolution of bacteria (Pseudomonas spp.) in controlled laboratory environments to investigate the role of environmental heterogeneity in the evolution of phenotypic diversity. Some of my results provide insight on general processes, while others are specific to ba...

  1. Effect of tourmaline on denitrification characteristics of hydrogenotrophic bacteria.

    Wang, Wei; Jiang, Hongyan; Zhu, Guangquan; Song, Xueying; Liu, Xingyu; Qiao, Ya

    2016-03-01

    To improve the denitrification characteristics of anaerobic denitrifying bacteria and obviate the disadvantage of use of explosive hydrogen gas, tourmaline, a polar mineral, was added to the hydrogenotrophic denitrification system in this study. Microbial reduction of nitrate in the presence of tourmaline was evaluated to assess the promotion effect of tourmaline on nitrate biodegradation. The experiment results demonstrated that tourmaline speeded up the cultivation process of bacteria from 65 to 36 days. After domestication of the bacteria, nitrate (50 mg NO3 (-)-N L(-1)) was completely removed within 3 days in the combined tourmaline-bacteria system, and the generated nitrite was also removed within 8 days. The reduction rate in this system is higher relative to that in the bacteria system alone. Efficient removal of nitrate by tourmaline-supported anaerobic bacteria (without external hydrogen input) indicated that tourmaline might act as the sole hydrogen donor to sustain autotrophic denitrification. Besides the production of hydrogen, the promoted activity of anaerobic denitrifying bacteria might be caused by the change of water properties, e.g., the pH of aqueous solutions was altered to about 8.0 and the oxidation-reduction potential decreased by 62 % in the tourmaline system. The distinctive effects of tourmaline on bacteria were related to its electric properties. PMID:26545889

  2. Use of thermophilic bacteria for bioremediation of petroleum contaminants

    Several strains of thermophilic bacteria were isolated from the environment of the United Arab Emirates. These bacteria show extraordinary resistance to heat and have their maximum growth rate around 60--80 C. This article investigates the potential of using these facultative bacteria for both in situ and ex situ bioremediation of petroleum contaminants. In a series of batch experiments, bacterial growth was observed using a computer image analyzer following a recently developed technique. These experiments showed clearly that the growth rate is enhanced in the presence of crude oil. This is coupled with a rapid degradation of the crude oil. These bacteria were found to be ideal for breaking down long-chain organic molecules at a temperature of 40 C, which is the typical ambient temperature of the Persian Gulf region. The same strains of bacteria are also capable of surviving in the presence of the saline environment that can prevail in both sea water and reservoir connate water. This observation prompted further investigation into the applicability of the bacteria in microbial enhanced oil recovery. In the United Arab Emirates, the reservoirs are typically at a temperature of around 85 C. Finally, the performance of the bacteria is tested in a newly developed bioreactor that uses continuous aeration through a transverse slotted pipe. This reactor also uses mixing without damaging the filamentous bacteria. In this process, the mechanisms of bioremediation are identified

  3. Computational Challenges in Characterization of Bacteria and Bacteria-Host Interactions Based on Genomic Data

    Chao Zhang; Guo-lu Zheng; Shun-Fu Xu; Dong Xu

    2012-01-01

    With the rapid development of next-generation sequencing technologies,bacterial identification becomes a very important and essential step in processing genomic data,especially for metagenomic data.Many computational methods have been developed and some of them are widely used to address the problems in bacterial identification.In this article we review the algorithms of these methods,discuss their drawbacks,and propose future computational methods that use genomic data to characterize bacteria.In addition,we tackle two specific computational problems in bacterial identification,namely,the detection of host-specific bacteria and the detection of disease-associated bacteria,by offering potential solutions as a starting point for those who are interested in the area.

  4. Bacteria-bacteria interactions within the microbiota of the ancestral metazoan Hydra contribute to fungal resistance.

    Fraune, Sebastian; Anton-Erxleben, Friederike; Augustin, René; Franzenburg, Sören; Knop, Mirjam; Schröder, Katja; Willoweit-Ohl, Doris; Bosch, Thomas C G

    2015-07-01

    Epithelial surfaces of most animals are colonized by diverse microbial communities. Although it is generally agreed that commensal bacteria can serve beneficial functions, the processes involved are poorly understood. Here we report that in the basal metazoan Hydra, ectodermal epithelial cells are covered with a multilayered glycocalyx that provides a habitat for a distinctive microbial community. Removing this epithelial microbiota results in lethal infection by the filamentous fungus Fusarium sp. Restoring the complex microbiota in gnotobiotic polyps prevents pathogen infection. Although mono-associations with distinct members of the microbiota fail to provide full protection, additive and synergistic interactions of commensal bacteria are contributing to full fungal resistance. Our results highlight the importance of resident microbiota diversity as a protective factor against pathogen infections. Besides revealing insights into the in vivo function of commensal microbes in Hydra, our findings indicate that interactions among commensal bacteria are essential to inhibit pathogen infection. PMID:25514534

  5. Sevelamer is an Effective Drug in Treating Hyperphosphatemia Due to Tumor Lysis Syndrome in Children: A Developing World Experience.

    Kahlon, Dilraj Kaur; Dinand, Veronique; Yadav, Satya Prakash; Sachdeva, Anupam

    2016-03-01

    We report here a study on efficacy of sevelamer hydrochloride in treating hyperphosphatemia due to tumor lysis syndrome (TLS) in a developing world setting. Twenty one children with hyperphosphatemia due to TLS were included. All received hyper-hydration, allopurinol and sevelamer. Efficacy was assessed by decrease in serum phosphate level, calcium-phosphate product and TLS score as per Cairo Bishop definition. Four children who underwent dialysis were excluded from analysis. Among the remaining 17 patients with hyperphosphatemia, laboratory TLS was recorded in 15 patients and clinical TLS in five. Sevelamer was given according to weight, most often 400 mg twice to thrice daily. Mean phosphatemia decreased from 8.3 ± 3.0 to 6.7 ± 2.1 mg/dl within 24 h of starting sevelamer (p = 0.02), 6.0 ± 2.1 mg/dl at 48 h, 4.9 ± 1.5 mg/dl at 72 h and 4.39 ± 1.7 mg/dl at 96 h. TLS was corrected in 72 h in 14 patients, 96 h in 1 and 120 h in another patient. Mean calcium-phosphate product decreased from 63.0 ± 14.0 to 49.2 ± 9.7 mg/dl (p = 0.002) at 24 h, 46.1 ± 17.0 mg/dl at 48 h and 39.7 ± 13.5 mg/dl at 72 h. There was no mortality due to hyperphosphatemia. Sevelamer is efficacious in children with malignancy-associated hyperphosphatemia in the developing world. PMID:26855510

  6. Determination of Ammonia Oxidizing Bacteria and Nitrate Oxidizing Bacteria in Wastewater and Bioreactors

    Francis, Somilez Asya

    2014-01-01

    The process of water purification has many different physical, chemical, and biological processes. One part of the biological process is the task of ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB). Both play critical roles in the treatment of wastewater by oxidizing toxic compounds. The broad term is nitrification, a naturally occurring process that is carried out by AOB and NOB by using oxidation to convert ammonia to nitrite and nitrite to nitrate. To monitor this biological activity, bacterial staining was performed on wastewater contained in inoculum tanks and biofilm samples from bioreactors. Using microscopy and qPCR, the purpose of this experiment was to determine if the population of AOB and NOB in wastewater and membrane bioreactors changed depending on temperature and hibernation conditions to determine the optimal parameters for AOB/NOB culture to effectively clean wastewater.

  7. Positively selected Leu-11a (CD16+) cells require the presence of accessory cells or factors for the lysis of herpes simplex virus-infected fibroblasts but not herpes simplex virus-infected Raji.

    Fitzgerald-Bocarsly, P; Feldman, M; Curl, S; Schnell, J; Denny, T

    1989-08-15

    Previous studies from our laboratory indicated that human NK activity against HSV-infected fibroblasts (HSV-Fs) but not K562 targets was sensitive to treatment with anti-HLA-DR plus C. In the current study, we have selected Leu-11a+ (CD-16) cells by fluorescence activated cell sorting and found that although Leu-11a enriched populations lysed K562 targets in 14-h 51Cr-release assays, they were unable to kill HSV-Fs targets unless a Leu-11a-depleted population was added back to the effectors or unless known activators of NK cells (IFN-alpha or IL-2) were added to the assays. In contrast, Leu-11a-enriched populations were able to mediate ADCC against HSV-Fs in the presence of sera from HSV-seropositive individuals without the requirement for accessory cells. We have begun preliminary characterization of the accessory cells which allow lysis of HSV-Fs by NK cells: they are HLA-DR+ cells which enrich in the light density fractions of Metrizamide density gradients. They need be present in very small numbers for lysis to take place and are not MHC restricted in that heterologous add-backs between anti-HLA-DR plus C and anti-Leu-11b plus C-treated populations are capable of target cell lysis at levels similar to those achieved with the autologous add-backs. Further, the levels of lysis in heterologous add-back experiments reflected the lytic potential of the effector rather than the accessory cell donor. Finally, although the requirement for accessory cells for NK lysis has been demonstrated for fibroblasts infected with HSV-1, CMV, and VZV, lysis of HSV-infected Raji lymphoblastoid cells is relatively accessory-cell independent, indicating that the requirement for accessory cells for lysis by NK cells is not a property of all herpesvirus-infected targets. PMID:2526183

  8. Study of fatty acid-bacteria interactions

    Complete text of publication follows. During our work we investigated fatty acid-bacteria interactions. The antibacterial property of fatty acids was reported by several authors. Despite of them there is not reassuring explanation about the mechanism of the antibacterial activity of these compounds. An effect can considerably change in case of different structured fatty acids. Our earlier studies conduct that small changes in the structures can modify changes in their behavior towards bacteria. The stearic acid does not cause any antibacterial effects during the first few hours of the investigation, may even help the bacterial growth. However, linolic acid (C18:2) shows a strong antibacterial effect during the first hours. After 24 hours this effect wears out and the bacteria have adapted to the stress. We studied the antibacterial activity using direct bioautography. This method has the advantage to allow examining lipophilic compounds. The linoleic acid decomposes in time under different physiological conditions creating numerous oxidized molecules. This may be the reason of its antimicrobial effect. For studying this phenomenon we used infrared and mass spectroscopic methods. We applied infrared spectroscopy for indicating any changes in the spectra of the fatty acids after the interaction of fatty acids with bacteria. So we are able to deduct on what could happen during these process. We paid great attention towards the changes of double bonds, on methylation and demethylation processes. Using mass spectroscopy we searched for oxidized products that may play important role in this process. These studies are only part of our more widespreading investigations, dealing with the antimicrobial properties of fatty acids.

  9. EspP, an Extracellular Serine Protease from Enterohemorrhagic E. coli, Reduces Coagulation Factor Activities, Reduces Clot Strength, and Promotes Clot Lysis

    Kuo, Kevin H. M.; Khan, Shekeb; Rand, Margaret L.; Mian, Hira S.; Brnjac, Elena; Sandercock, Linda E.; Akula, Indira; Julien, Jean-Philippe; Pai, Emil F.; Chesney, Alden E.

    2016-01-01

    Background EspP (E. coli secreted serine protease, large plasmid encoded) is an extracellular serine protease produced by enterohemorrhagic E. coli (EHEC) O157:H7, a causative agent of diarrhea-associated Hemolytic Uremic Syndrome (D+HUS). The mechanism by which EHEC induces D+HUS has not been fully elucidated. Objectives We investigated the effects of EspP on clot formation and lysis in human blood. Methods Human whole blood and plasma were incubated with EspPWT at various concentrations and...

  10. A novel trifunctional IgG-like bispecific antibody to inhibit HIV-1 infection and enhance lysis of HIV by targeting activation of complement

    Tomlinson Stephen

    2010-06-01

    Full Text Available Abstract Background The complement system is not only a key component of innate immunity but also provides a first line of defense against invading pathogens, especially for viral pathogens. Human immunodeficiency virus (HIV, however, possesses several mechanisms to evade complement-mediated lysis (CoML and exploit the complement system to enhance viral infectivity. Responsible for this intrinsic resistance against complement-mediated virolysis are complement regulatory membrane proteins derived from the host cell that inherently downregulates complement activation at several stages of the cascade. In addition, HIV is protected from complement-mediated lysis by binding soluble factor H (fH through the viral envelope proteins, gp120 and gp41. Whereas inhibition of complement activity is the desired outcome in the vast majority of therapeutic approaches, there is a broader potential for complement-mediated inhibition of HIV by complement local stimulation. Presentation of the hypothesis Our previous studies have proven that the complement-mediated antibody-dependent enhancement of HIV infection is mediated by the association of complement receptor type 2 bound to the C3 fragment and deposited on the surface of HIV virions. Thus, we hypothesize that another new activator of complement, consisting of two dsFv (against gp120 and against C3d respectively linked to a complement-activating human IgG1 Fc domain ((anti-gp120 × anti-C3d-Fc, can not only target and amplify complement activation on HIV virions for enhancing the efficiency of HIV lysis, but also reduce the infectivity of HIV through blocking the gp120 and C3d on the surface of HIV. Testing the hypothesis Our hypothesis was tested using cell-free HIV-1 virions cultivated in vitro and assessment of virus opsonization was performed by incubating appropriate dilutions of virus with medium containing normal human serum and purified (anti-gp120 × anti-C3d-Fc proteins. As a control group, viruses

  11. Changes in clot lysis levels of reteplase and streptokinase following continuous wave ultrasound exposure, at ultrasound intensities following attenuation from the skull bone

    Roijer Anders

    2008-08-01

    Full Text Available Abstract Background Ultrasound (US has been used to enhance thrombolytic therapy in the treatment of stroke. Considerable attenuation of US intensity is however noted if US is applied over the temporal bone. The aim of this study was therefore to explore possible changes in the effect of thrombolytic drugs during low-intensity, high-frequency continuous-wave ultrasound (CW-US exposure. Methods Clots were made from fresh venous blood drawn from healthy volunteers. Each clot was made from 1.4 ml blood and left to coagulate for 1 hour in a plastic test-tube. The thrombolytic drugs used were, 3600 IU streptokinase (SK or 0.25 U reteplase (r-PA, which were mixed in 160 ml 0.9% NaCl solution. Continuous-wave US exposure was applied at a frequency of 1 MHz and intensities ranging from 0.0125 to 1.2 W/cm2. For each thrombolytic drug (n = 2, SK and r-PA and each intensity (n = 9 interventional clots (US-exposed, n = 6 were submerged in thrombolytic solution and exposed to CW-US while control clots (also submerged in thrombolytic solution, n = 6 were left unexposed to US. To evaluate the effect on clot lysis, the haemoglobin (Hb released from each clot was measured every 20 min for 1 hour (20, 40 and 60 min. The Hb content (mg released was estimated by spectrophotometry at 540 nm. The difference in effect on clot lysis was expressed as the difference in the amount of Hb released between pairs of US-exposed clots and control clots. Statistical analysis was performed using Wilcoxon's signed rank test. Results Continuous-wave ultrasound significantly decreased the effects of SK at intensities of 0.9 and 1.2 W/cm2 at all times (P 2 and at 1.2 W/cm2, following 40 min exposure at 0.3, 0.6, 0.9 and at 1.2 W/cm2, and following 60 min of exposure at 0.05 0.3, 0.6, 0.9 and at 1.2 W/cm2 (all P Conclusion Increasing intensities of CW-US exposure resulted in increased clot lysis of r-PA-treated blood clots, but decreased clot lysis of SK-treated clots.

  12. Effect of Ionizing Radiation on Luminous Bacteria Cells

    Marine luminous bacteria were used to monitor toxicity of alpha- (Am-241, U-235+238) and beta- (tritium) radionuclide solutions. Increase or inhibition of bacterial luminescence was observed under exposure to radionuclides. Radiation toxicity of Am and chemical toxicity of U were demonstrated. Effects of U were similar to those of stable heavy metals: sensitivity was about 10-5 M. Sensitivity of the bacteria to Am-241 was 300 Bq/L (10-11M). Inhibition of bacterial growth was observed under exposure to Am-241 and tritium. Role of peroxides and electron transfer processes in the effects of radionuclides on luminous bacteria is discussed.

  13. Psychrotrophic ~Iydrolytic Bacteria from Antarctica &,Other I. Low Temperature Habitats

    K.V. Ramana

    2000-04-01

    Full Text Available Samples of water, soil,llake sediments and blue-green algal mats from Antarctica were'processed for enumeration, isolation and screening of psychrotrophic hydrolytic bacteria. Amylolytic bacteria were preponderant (75 per cent in the blue-green algal htat samples. Protease, lipase, an1ylase and urerse producing/bacteria were also isolated from the samples. ,Biochemical characteristics indicated that the isolates ;mainly comprised Pseudomonas and Bacillus species. Proteases and lipases of antarctic bacterial strains preferably hydrolysed denatured protein substrate and water soluble monomeric synthetic lipid substrates, respectively.

  14. Modelling the fate and transport of faecal bacteria in estuarine and coastal waters.

    Gao, Guanghai; Falconer, Roger A; Lin, Binliang

    2015-11-15

    This paper details a numerical model developed to predict the fate and transport of faecal bacteria in receiving surface waters. The model was first validated by comparing model predicted faecal bacteria concentrations with available field measurements. The model simulations agreed well with the observation data. After calibration, the model was applied to investigate the effects of different parameters, including: tidal processes, river discharges from the upstream boundaries and bacteria inputs from the upstream boundaries, wastewater treatment works (WwTWs), rivers and combined sewer overflows (CSO), on the concentrations of faecal bacteria in the Ribble Estuary. The results revealed that the tide and upstream boundary bacteria inputs were the primary factors controlling the distribution of faecal bacteria. The bacteria inputs from the WwTWs in the model domain were generally found not to have a significant impact on distribution of faecal bacteria in the estuary. PMID:26384864

  15. Beer spoilage bacteria and hop resistance

    Sakamoto, K; Konings, WN

    2003-01-01

    For brewing industry, beer spoilage bacteria have been problematic for centuries. They include some lactic acid bacteria such as Lactobacillus brevis, Lactobacillus lindneri and Pediococcus damnosus, and some Gram-negative bacteria such as Pectinatus cerevisiiphilus, Pectinatus frisingensis and Mega

  16. The impact of lactic acid bacteria on sourdough fermentation

    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...

  17. Bacteria heap leaching test of a uranium ore

    Column bioleaching test of a uranium ore was carried out. The optimum acidity, spraying intensity, spray-pause time ratio were determined. The potential, Fe and U concentrations in the leaching process were investigated. The effect of bacteria column leaching was compared with that of acid column leaching. The results show that bacteria column leaching can shorten leaching cycle, and the leaching rate of uranium increases by 9.7%. (authors)

  18. ISOLATION AND IDENTIFICATION OF ACR YLAMIDE DEGRADING BACTERIA FROM SOIL

    Nidhi Jain; John, P. J.; Kanti Prakash Sharma; Soni, I.

    2013-01-01

    Acrylamide is an aliphatic amide, which is produced by industrial processes and during heating of food. It is neurotoxic and a suspected carcinogen. In the present study an attempt was made to isolate acrylamide degrading bacteria from soil. The optimum growth conditions and physiological characteristics for the isolated acrylamide degrading bacteria were investigated. The isolated bacterium was identified as Bacillus clausii strain 1779 based on full 16S rRNA molecular phylogeny. The bacteri...

  19. Microbial Cellulose Production from Bacteria Isolated from Rotten Fruit

    Rangaswamy, B.E.; Vanitha, K. P.; Hungund, Basavaraj S.

    2015-01-01

    Microbial cellulose, an exopolysaccharide produced by bacteria, has unique structural and mechanical properties and is highly pure compared to plant cellulose. Present study represents isolation, identification, and screening of cellulose producing bacteria and further process optimization. Isolation of thirty cellulose producers was carried out from natural sources like rotten fruits and rotten vegetables. The bacterial isolates obtained from rotten pomegranate, rotten sweet potato, and rott...

  20. Screening of aspartate dehydrogenase of bacteria

    Fukuda, Shoko; Okamura, Tokumitsu; Yasumasa, Izumi; Takeno, Tomomi; Ohsugi, Masahiro

    2001-01-01

    Fifty-two strains of bacteria cultured under aerobic conditions and 12 strains of bacteria cultured under anaerobic conditions demonstrated high activity staining of aspartate dehydrogenase with NAD^+. Four strains of bacteria cultured under aerobic conditions and 7 strains of bacteria cultured under anaerobic conditions demonstrated high activity staining of aspartate dehydrogenase with NADP^+. Seven strains of bacteria cultured under aerobic conditions and 4 strains of bacteria cultured und...

  1. Sewage-pollution indicator bacteria

    Ramaiah, N.; Rodrigues, V.; Alwares, E.; Rodrigues, C.; Baksh, R.; Jayan, S.; Mohandass, C.

    increased. It is only recently that sewage from major cities like Panaji, Goa, India is treated before disposing into the estuary. It is therefore of interest to determine what the levels of pollution indicator bacteria due to sewage disposal...

  2. A Simple Method for DNA Extraction from Mature Date Palm Leaves: Impact of Sand Grinding and Composition of Lysis Buffer

    Mohammad Al Sadoon

    2010-09-01

    Full Text Available Molecular marker techniques have been widely used for cultivar identification of inbred date palms (Phoenix dactylifera L.; Arecaceae and biodiversity conservation. Isolation of highly pure DNA is the prerequisite for PCR amplification and subsequent use such as DNA fingerprinting and sequencing of genes that have recently been developed for barcoding. To avoid problems related to the preservation and use of liquid nitrogen, we examined sterile sand for grinding the date palm leaves. Individual and combined effects of sodium chloride (NaCl, polyvinylpyrrolidone (PVP and lithium chloride (LiCl with the cetyltrimethylammonium bromide (CTAB method for a DNA yield of sufficient purity and PCR amplification were evaluated in this study. Presence of LiCl and PVP alone or together in the lysis buffer did not significantly improve the DNA yield and purity compared with the addition of NaCl. Our study suggested that grinding of date palm leaf with sterile sand and inclusion of NaCl (1.4 M in the lysis buffer without the costly use of liquid nitrogen, PVP and LiCl, provides a DNA yield of sufficient purity, suitable for PCR amplification.

  3. Thymidine kinase diversity in bacteria

    Sandrini, Michael; Clausen, A.R.; Munch-Petersen, B.;

    2006-01-01

    Thymidine kinases (TKs) appear to be almost ubiquitous and are found in nearly all prokaryotes, eukaryotes, and several viruses. They are the key enzymes in thymidine salvage and activation of several anti-cancer and antiviral drugs. We show that bacterial TKs can be subdivided into 2 groups. The...... TKs from Gram-positive bacteria are more closely related to the eukaryotic TK1 enzymes than are TKs from Gram-negative bacteria....

  4. LACTIC ACID BACTERIA: PROBIOTIC APPLICATIONS

    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...

  5. Adherention ability of intestinal bacteria

    Morgensternová, Tereza

    2014-01-01

    Probiotics are live microorganisms that provide positive health benefits. Bacteria of the genus Bifidobacterium belong to this group. These bacteria have to meet a number of criteria so that they could be considered for probiotic. These include the ability to survive, grow, and be metabolically active in the gastrointestinal tract of the recipient. Probiotics protect the intestinal mucus from the adhesion of pathogenic organisms. The aim of this thesis was to test the ability of different ...

  6. Thymidine kinase diversity in bacteria

    Sandrini, Michael; Clausen, A.R.; Munch-Petersen, B.; Piskur, Jure

    Thymidine kinases (TKs) appear to be almost ubiquitous and are found in nearly all prokaryotes, eukaryotes, and several viruses. They are the key enzymes in thymidine salvage and activation of several anti-cancer and antiviral drugs. We show that bacterial TKs can be subdivided into 2 groups. The...... TKs from Gram-positive bacteria are more closely related to the eukaryotic TK1 enzymes than are TKs from Gram-negative bacteria....

  7. A comparative effect of 3 disinfectants on heterotrophic bacteria, iron bacteria and sulfate-reducing bacteria

    2006-01-01

    The disinfection effect of chlorine dioxide, chlorine and their mixture on heterotrophic bacteria, iron bacteria and sulfate-reducing bacteria in circulating cooling water was studied. The results of the test indicated that high purity chlorine dioxide was the most effective biocide in the 3 disinfectants, and with a dosage of 0.5mg/L, chlorine dioxide could obtain perfect effect. High purity chloride dioxide could have the excellent effect with the pH value of 6 to 10, and could keep it within 72 h. Chlorine and their mixture couldn't reach the effect of chlorine dioxide.

  8. The ecological distributions of N, P utilizing bacteria and heterotrophic bacteria in the moderate hypoxia zone of the Changjiang Estuary

    Liu, Jingjing; Du, Ping; Zeng, Jiangning; Chen, Quanzhen; Shou, Lu; Liao, Yibo; Jiang, Zhibing

    2013-12-01

    The distributions of N utilizing bacteria (denitrifying bacteria and ammonifying bacteria), P utilizing bacteria (organic phosphobacteria and inorganic phosphobacteria) and heterotrophic bacteria in the Changjiang Estuary, and the roles of main environmental factors in distributing bacteria, are explored with observations from two cruises in June and August 2006. Comparisons between the two important periods of initial hypoxia phase (June) and developed hypoxia phase (August) show differences in both bacterial distributions and the associated main environmental factors. First, the primary group of ammonifying bacteria has larger magnitude with spatial maximum value in the hypoxic stations related to sediment in August. The phosphobacterial abundance and detection rates in August are much lower than those in June, but the denitrifying bacterial abundance becomes greater in August. However, the difference of heterotrophic bacterial abundance between June and August is not obvious. Second, main environmental factors influencing bacteria vary from initial hypoxia phase to developed hypoxia phase. Two parameters (salinity and NO3 -) in surface water and five environmental parameters (pH, salinity, PO4 3-, NO3 - and temperature) in bottom water and surface sediment play major roles in the bacterial abundance in June, while different parameter combinations (salinity and PO4 -) in surface water and different parameter combinations (DO, DOC, NO3 -, PO4 3- and pH) in bottom water and surface sediment play major roles in August. Moreover, the bottom bacteria distributions in area south of 31°N are related to the position of the Taiwan Warm Current in June. The bacterial abundance and distribution may respond to the environmental change in the hypoxia processes of initial phase and developed phase. During the hypoxia processes, the whole structure of bacterial functional groups probably turns to different states, causing the recycling of nutrient regeneration and aggravating

  9. Chemotaxis signaling systems in model beneficial plant-bacteria associations.

    Scharf, Birgit E; Hynes, Michael F; Alexandre, Gladys M

    2016-04-01

    Beneficial plant-microbe associations play critical roles in plant health. Bacterial chemotaxis provides a competitive advantage to motile flagellated bacteria in colonization of plant root surfaces, which is a prerequisite for the establishment of beneficial associations. Chemotaxis signaling enables motile soil bacteria to sense and respond to gradients of chemical compounds released by plant roots. This process allows bacteria to actively swim towards plant roots and is thus critical for competitive root surface colonization. The complete genome sequences of several plant-associated bacterial species indicate the presence of multiple chemotaxis systems and a large number of chemoreceptors. Further, most soil bacteria are motile and capable of chemotaxis, and chemotaxis-encoding genes are enriched in the bacteria found in the rhizosphere compared to the bulk soil. This review compares the architecture and diversity of chemotaxis signaling systems in model beneficial plant-associated bacteria and discusses their relevance to the rhizosphere lifestyle. While it is unclear how controlling chemotaxis via multiple parallel chemotaxis systems provides a competitive advantage to certain bacterial species, the presence of a larger number of chemoreceptors is likely to contribute to the ability of motile bacteria to survive in the soil and to compete for root surface colonization. PMID:26797793

  10. Cable Bacteria in Freshwater Sediments.

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus B; Dittmer, Anders Lindequist; Bjerg, Jesper Tataru; Trojan, Daniela; Schreiber, Lars; Damgaard, Lars Riis; Schramm, Andreas; Nielsen, Lars Peter

    2015-09-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures and electric fields indicated electron transfer between vertically separated anodic and cathodic half-reactions. Fluorescence in situ hybridization revealed the presence of Desulfobulbaceae filaments. In addition, in situ measurements of oxygen, pH, and electric potential distributions in the waterlogged banks of Giber Å demonstrated the presence of distant electric redox coupling in naturally occurring freshwater sediment. At the same site, filamentous Desulfobulbaceae with cable bacterium morphology were found to be present. Their 16S rRNA gene sequence placed them as a distinct sister group to the known marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary origin of the cable phenotype within Desulfobulbaceae with subsequent diversification into a freshwater and a marine lineage. PMID:26116678

  11. Bioreporter bacteria for landmine detection

    Burlage, R.S. [Oak Ridge National Lab., TN (United States); Youngblood, T. [Frisby Technologies, Aiken, SC (United States); Lamothe, D. [American Technologies, Inc., Huntsville, AL (United States). Ordnance/Explosives Environmental Services Div.

    1998-04-01

    Landmines (and other UXO) gradually leak explosive chemicals into the soil at significant concentrations. Bacteria, which have adapted to scavenge low concentrations of nutrients, can detect these explosive chemicals. Uptake of these chemicals results in the triggering of specific bacterial genes. The authors have created genetically recombinant bioreporter bacteria that detect small concentrations of energetic chemicals. These bacteria are genetically engineered to produce a bioluminescent signal when they contact specific explosives. A gene for a brightly fluorescent compound can be substituted for increased sensitivity. By finding the fluorescent bacteria, you find the landmine. Detection might be accomplished using stand-off illumination of the minefield and GPS technology, which would result in greatly reduced risk to the deminers. Bioreporter technology has been proven at the laboratory scale, and will be tested under field conditions in the near future. They have created a bacterial strain that detects sub-micromolar concentrations of o- and p-nitrotoluene. Related bacterial strains were produced using standard laboratory protocols, and bioreporters of dinitrotoluene and trinitrotoluene were produced, screening for activity with the explosive compounds. Response time is dependent on the growth rate of the bacteria. Although frill signal production may require several hours, the bacteria can be applied over vast areas and scanned quickly, producing an equivalent detection speed that is very fast. This technology may be applicable to other needs, such as locating buried explosives at military and ordnance/explosive manufacturing facilities.

  12. Mineralization Capacity of Bacteria and Fungi from the Rhizosphere-Rhizoplane of a Semiarid Grassland

    Nakas, J. P.; Klein, D.A.

    1980-01-01

    A radiotracer glucose mineralization assay was used with streptomycin and actidione to monitor the relative seasonal contributions of bacteria and fungi to mineralization processes in soils derived from the rhizosphere-rhizoplane zone of plants from a shortgrass prairie ecosystem. Bacteria played a major role in glucose mineralization in both the rhizosphere and rhizoplane. These results indicate that the bacteria may play a greater role in glucose mineralization processes in the rhizosphere ...

  13. [Definition of the physiological condition of bacteria in soil by means of luminescent dye L7012].

    Lysak, L V; Lapygina, E V; Konova, I A; Zviagintsev, D G

    2009-01-01

    By means of dye L7012, the number and physiological condition (damage rate of membranes) of bacterial cells is defined. The results testify to considerable physiological heterogeneity of bacteria cells in soils. In fresh samples of soil, the percentage of intact cells reached 60-70%. Damaged membranes occurred in 30-40% of cells. The number of damaged cells dramatically increased downwards through the soil profile. Drying and freezing of soil samples considerably reduced the quantity of intact cells and increased the percentage of cells with damaged membranes; the number of intact cells was 10-20%. Treatment with biocide agents resulted in lysis of the majority of cells and cells injuries. However, some of the cells kept an intact cellular membrane, which testifies to the high stability of bacteria in soil. These data allow us to offer a method of staining a soil suspension with the use of luminescent dye L7012 with the quality of an express method that gives the chance to monitor the number and physiological condition of the bacterial complex of soils. PMID:20143636

  14. Process of producing mannitol and homopolysaccharides

    Geel-Schutten, Gerritdina Hendrika van; Binnema, Doede J.; van der Maarel, Marc

    2004-01-01

    The present invention relates to a process producing mannitol and one or more homopolysaccharides by bacteria. The bacteria according to the invention express mannitol-2-dehydrogenase activity and one or more sucrase activities. Preferably, the bacteria are lactic acid bacteria and more preferably t

  15. Bioleaching of marmatite using moderately thermophilic bacteria

    ZHOU Hong-bo; LIU Fei-fei; ZOU Ying-qin; ZENG Xiao-xi; QIU Guan-zhou

    2008-01-01

    The process of bioleaching marmatite using moderately thermophilic bacteria was studied by comparing marmatite leaching performance of mesophiles and moderate thermophiles and valuating the effect of venting capacity as well as pulp density on marmatite leaching performance of moderate thermophiles. The results show that moderate thermophiles have more advantages over mesophilies in bioleaching marmatite at 45℃ and the pulp density of 50g/L, and the zinc extraction efficiency reaches 93.1% in 20d. Aeration agitation can improve the transfer of O2 and CO2 in solution and promote the growth of bacteria and therefore, enhance the leaching efficiency. Under the venting levels of 50, 200 and 800mL/min, the zinc extraction efficiencies by moderate thermophiles are 57.8%, 92.5% and 96.0%, respectively. With the increase of pulp density, the total leaching amount of valuable metals increases, however, the extraction efficiency decreases due to many reasons, such as increasing shear force leading to poorly growth condition for bacteria, etc. The zinc extraction decreases remarkably to 58.9% while the pulp density mounts up 20%.

  16. Airborne bacteria in the atmosphere: Presence, purpose, and potential

    Smets, Wenke; Moretti, Serena; Denys, Siegfried; Lebeer, Sarah

    2016-08-01

    Numerous recent studies have highlighted that the types of bacteria present in the atmosphere often show predictable patterns across space and time. These patterns can be driven by differences in bacterial sources of the atmosphere and a wide range of environmental factors, including UV intensity, precipitation events, and humidity. The abundance of certain bacterial taxa is of interest, not only for their ability to mediate a range of chemical and physical processes in the atmosphere, such as cloud formation and ice nucleation, but also for their implications -both beneficial and detrimental-for human health. Consequently, the widespread importance of airborne bacteria has stimulated the search for their applicability. Improving air quality, modelling the dispersal of airborne bacteria (e.g. pathogens) and biotechnological purposes are already being explored. Nevertheless, many technological challenges still need to be overcome to fully understand the roles of airborne bacteria in our health and global ecosystems.

  17. Lipase Activity among Bacteria Isolated from Amazonian Soils.

    Willerding, André Luis; de Oliveira, Luiz Antonio; Moreira, Francisco Wesen; Germano, Mariana Gomes; Chagas, Aloísio Freitas

    2011-01-01

    The objective of this study was to select lipase-producing bacteria collected from different counties of the Amazon region. Of the 440 bacteria strains, 181 were selected for the lipase assay in qualitative tests at Petri dishes, being 75 (41%) lipase positive. The enzymatic index was determined during fifteen days at different temperatures (30°, 35°, 40°, and 45°C). The highest lipase activity was observed within 72 hours at 30°C. Twelve bacteria strains presented an index equal to or greater than the standard used like reference, demonstrating the potential of microbial resource. After the bioassay in Petri dishes, the selected bacteria strains were analyzed in quantitative tests on p-nitrophenyl palmitate (p-NPP). A group of the strains was selected for other phases of study with the use in oleaginous substrates of the Amazonian flora, aiming for the application in processes like oil biotransformation. PMID:22007294

  18. Lipase Activity among Bacteria Isolated from Amazonian Soils

    André Luis Willerding

    2011-01-01

    Full Text Available The objective of this study was to select lipase-producing bacteria collected from different counties of the Amazon region. Of the 440 bacteria strains, 181 were selected for the lipase assay in qualitative tests at Petri dishes, being 75 (41% lipase positive. The enzymatic index was determined during fifteen days at different temperatures (30°, 35°, 40°, and 45°C. The highest lipase activity was observed within 72 hours at 30°C. Twelve bacteria strains presented an index equal to or greater than the standard used like reference, demonstrating the potential of microbial resource. After the bioassay in Petri dishes, the selected bacteria strains were analyzed in quantitative tests on p-nitrophenyl palmitate (p-NPP. A group of the strains was selected for other phases of study with the use in oleaginous substrates of the Amazonian flora, aiming for the application in processes like oil biotransformation.

  19. Handcuffs for bacteria - NDP52 orchestrates xenophagy of intracellular Salmonella

    Pauline Verlhac

    2015-05-01

    Full Text Available Eukaryotic cells can selectively target and degrade intracellular pathogens using autophagy, a process referred to as xenophagy. This selectivity is controlled by proteins called autophagy receptors, which can recognise pathogens and address them to the autophagy machinery. Among them, NDP52 can recognise Salmonella Typhimurium on the one hand and the ATG8 family member LC3C on the other hand, thus allowing the docking of the bacteria to a growing autophagosome. Additionally, we recently reported that NDP52 is involved in the maturation of the bacteria-containing autophagosome and hence necessary for the ultimate degradation of the bacteria. These two functions of NDP52 are independent as they rely on distinct binding domains and protein partners. Therefore, NDP52 plays a dual role during xenophagy, first by targeting the bacteria to the autophagy machinery and then by regulating its degradation.

  20. Complement-dependent cellular cytotoxicity: lymphoblastoid lines that activate complement component 3 (C3) and express C3 receptors have increased sensitivity to lymphocyte-mediated lysis in the presence of fresh human serum.

    Ramos, O F; Sármay, G; Klein, E.; Yefenof, E; Gergely, J.

    1985-01-01

    Lymphocyte-mediated lysis of cells of the Raji, Daudi, Jijoye, and Bjab lines was elevated when fresh human serum was added to the assay. A higher proportion of effector-target conjugates was observed in the presence of human serum. In similar experiments lysis of 1301, Rael, and P3HR-1 cells was unaltered. All cell lines activated the alternative pathway of complement but they varied in the expression of receptors for complement component 3 (C3) and in the ability to fix the C3 cleavage prod...

  1. Metabolic Engineering of Bacteria

    Kumar, Ravi R.; Prasad, Satish

    2011-01-01

    Yield and productivity are critical for the economics and viability of a bioprocess. In metabolic engineering the main objective is the increase of a target metabolite production through genetic engineering. Metabolic engineering is the practice of optimizing genetic and regulatory processes within cells to increase the production of a certain substance. In the last years, the development of recombinant DNA technology and other related technologies has provided new tools for approaching yield...

  2. Relationship between repair processes and mutation induction in bacteria. [UV radiation; methyl methanesulfonate; N-methyl-N/sup 1/-nitro-N-nitrosoguanidine; N-methyl-N-nitrosourea; N-ethyl-N-nitrosourea; ethyl methanesulfanate; N-ethyl-nitrosoguanidine; 4-nitroquinoline 1-oxide

    Kimball, R F

    1979-01-01

    The main repair and replication-associated processes that can influence the induction of mutations by various mutagens in bacteria are reviewed. These include both constitutive and induced, error-free and error-prone systems. The mutation yield from a treatment with a mutagen can be markedly affected by which of these systems is operating in a given bacterial species or strain. The effect of these systems on mutation induction by ultraviolet light, monofunctional alkylating agents, base analogues, and frameshift mutagens is discussed in some detail. The bearing of these studies on the practical problems of estimating hazards is briefly considered. 79 references.

  3. IDENTIFICATION OF BACTERIA IN LATEX PAINTS

    Rojas, J.

    2008-01-01

    Full Text Available The bacteria are prokaryote organisms with a high capacity to colonize many types of habits. This research was developed with the object to identify extremophiles bacteria presents in latex paint. The bacteria were cultivated in culture mediums TSA, Blood Agar, Mc Conkey and finally the biochemical proof API-NF® for bacteria's isolation and identification, respectively. Characterization showed bacterial profile of Pasteurella sp. Hypothesis that could be found extremophiles bacteria in latex paint were demonstrated.

  4. Electron transport chains of lactic acid bacteria

    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...

  5. Chitin Degradation In Marine Bacteria

    Paulsen, Sara; Machado, Henrique; Gram, Lone

    2015-01-01

    Introduction: Chitin is the most abundant polymer in the marine environment and the second most abundant in nature. Chitin does not accumulate on the ocean floor, because of microbial breakdown. Chitin degrading bacteria could have potential in the utilization of chitin as a renewable carbon and...... nitrogen source in the fermentation industry.Methods: Here, whole genome sequenced marine bacteria were screened for chitin degradation using phenotypic and in silico analyses.Results: The in silico analyses revealed the presence of three to nine chitinases in each strain, however the number of chitinases...... chitin regulatory system.Conclusions: This study has provided insight into the ecology of chitin degradation in marine bacteria. It also served as a basis for choosing a more efficient chitin degrading production strain e.g. for the use of chitin waste for large-scale fermentations....

  6. Methylotrophic bacteria in sustainable agriculture.

    Kumar, Manish; Tomar, Rajesh Singh; Lade, Harshad; Paul, Diby

    2016-07-01

    Excessive use of chemical fertilizers to increase production from available land has resulted in deterioration of soil quality. To prevent further soil deterioration, the use of methylotrophic bacteria that have the ability to colonize different habitats, including soil, sediment, water, and both epiphytes and endophytes as host plants, has been suggested for sustainable agriculture. Methylotrophic bacteria are known to play a significant role in the biogeochemical cycle in soil ecosystems, ultimately fortifying plants and sustaining agriculture. Methylotrophs also improve air quality by using volatile organic compounds such as dichloromethane, formaldehyde, methanol, and formic acid. Additionally, methylotrophs are involved in phosphorous, nitrogen, and carbon cycling and can help reduce global warming. In this review, different aspects of the interaction between methylotrophs and host plants are discussed, including the role of methylotrophs in phosphorus acquisition, nitrogen fixation, phytohormone production, iron chelation, and plant growth promotion, and co-inoculation of these bacteria as biofertilizers for viable agriculture practices. PMID:27263015

  7. Parotitis due to anaerobic bacteria.

    Matlow, A; Korentager, R; Keystone, E; Bohnen, J

    1988-01-01

    Although Staphylococcus aureus remains the pathogen most commonly implicated in acute suppurative parotitis, the pathogenic role of gram-negative facultative anaerobic bacteria and strict anaerobic organisms in this disease is becoming increasingly recognized. This report describes a case of parotitis due to Bacteroides disiens in an elderly woman with Sjögren's syndrome. Literature reports on seven additional cases of suppurative parotitis due to anaerobic bacteria are reviewed. Initial therapy of acute suppurative parotitis should include coverage for S. aureus and, in a very ill patient, coverage of gram-negative facultative organisms with antibiotics such as cloxacillin and an aminoglycoside. A failure to respond clinically to such a regimen or isolation of anaerobic bacteria should lead to the consideration of the addition of clindamycin or penicillin. PMID:3287567

  8. Antimicrobial activity, improved cell selectivity and mode of action of short PMAP-36-derived peptides against bacteria and Candida.

    Lyu, Yinfeng; Yang, Yang; Lyu, Xiting; Dong, Na; Shan, Anshan

    2016-01-01

    Antimicrobial peptides (AMPs) have recently attracted a great deal of attention as promising antibiotic candidates, but some obstacles such as toxicity and high synthesis cost must be addressed before developing them further. For developing short peptides with improved cell selectivity, we designed a series of modified PMAP-36 analogues. Antimicrobial assays showed that decreasing chain length in a certain range retained the high antimicrobial activity of the parental peptide and reduced hemolysis. The 18-mer peptide RI18 exhibited excellent antimicrobial activity against both bacteria and fungi, and its hemolytic activity was observably lower than PMAP-36 and melittin. The selectivity indexes of RI18 against bacteria and fungi were improved approximately 19-fold and 108-fold, respectively, compared to PMAP-36. In addition, serum did not affect the antibacterial activity of RI18 against E. coli but inhibited the antifungal efficiency against C. albicans. Flow cytometry and electron microscopy observation revealed that RI18 killed microbial cells primarily by damaging membrane integrity, leading to whole cell lysis. Taken together, these results suggest that RI18 has potential for further therapeutic research against frequently-encountered bacteria and fungi. Meanwhile, modification of AMPs is a promising strategy for developing novel antimicrobials to overcome drug-resistance. PMID:27251456

  9. Effects of viruses on bacterial functions under contrasting nutritional conditions for four species of bacteria isolated from Hong Kong waters

    Liu, Hao; Yuan, Xiangcheng; Xu, Jie; Harrison, Paul J.; He, Lei; Yin, Kedong

    2015-09-01

    Free living viruses are ubiquitous in marine waters and concentrations are usually several times higher than the bacterial abundance. These viruses are capable of lysing host bacteria and therefore, play an important role in the microbial loop in oligotrophic waters. However, few studies have been conducted to compare the role of viruses in regulating bacterial abundance and heterotrophic activities between natural oligotrophic waters and anthropogenic influenced eutrophic waters. In this study, we examined viral effects on bacterial functions of four single bacterial species incubated with natural viral assemblages in seawater samples from eutrophic and oligotrophic waters. The viral-lysis of bacteria was significantly higher in eutrophic than oligotrophic waters. This suggests that viruses were capable of controlling bacterial abundance, respiration and production in the eutrophic waters. Cellular bacterial respiration and production was higher with viruses than without viruses, which was more evident in the oligotrophic waters. These results indicate that viruses can slow down bacterial consumption of oxygen and reduce bacteria-induced eutrophication effects in anthropogenic eutrophic waters, but switch to the role of sustaining the bacterial population when nutrients are limiting. There were bacterial species differences in resisting viral attack, which can influence the dominance and biodiversity of bacterial species in coastal waters.

  10. Bacteria transport through porous media. Annual report, December 31, 1984

    Yen, T.F.

    1986-09-01

    The following five chapters in this report have been processed separately for inclusion in the Energy Data Base: (1) theoretical model of convective diffusion of motile and non-motile bacteria toward solid surfaces; (2) interfacial electrochemistry of oxide surfaces in oil-bearing sands and sandstones; (3) effects of sodium pyrophosphate additive on the ''huff and puff''/nutrient flooding MEOR process; (4) interaction of Escherichia coli B, B/4, and bacteriophage T4D with Berea sandstone rock in relation to enhanced oil recovery; and (5) transport of bacteria in porous media and its significance in microbial enhanced oil recovery.

  11. Theory of periodic swarming of bacteria application to Proteus mirabilis

    Czirok, A; Vicsek, T; Czirok, Andras; Matsushita, Mitsugu; Vicsek, Tamas

    2001-01-01

    The periodic swarming of bacteria is one of the simplest examples for pattern formation produced by the self-organized collective behavior of a large number of organisms. In the spectacular colonies of Proteus mirabilis (the most common species exhibiting this type of growth) a series of concentric rings are developed as the bacteria multiply and swarm following a scenario periodically repeating itself. We have developed a theoretical description for this process in order to get a deeper insight into some of the typical processes governing the phenomena in systems of many interacting living units. All of our theoretical results are in excellent quantitative agreement with the complete set of available observations.

  12. Application of rapid-lysis techniques in radiobiology. IV. The effect of glycerol and DMSO on Chinese hamster cell survival and DNA single-strand break production

    A rapid-lysis technique has been used to compare the initial yield of DNA single-strand breaks (ssb) measured 0.2 sec after irradiation and cell survival for Chinese hamster cells in vitro. Both DMSO and glycerol protected cells irradiated in air, and there was a simple relationship between relative radiosensitivity and the initial number of ssb. Under oxic conditions at high concentrations (2 M) of either agent the yield of ssb was reduced by a factor of 3 and the slope of the survival curve by a factor of 2. Under hypoxic conditions much less protection was noted, and even at high concentrations of either agent (2 M) there was only a small degree of protection against cell inactivation and ssb

  13. Interdisciplinary Physics and Related Areas of Science and Technology Entropy Production Rate Changes in Lysogeny/Lysis Switch Regulation of Bacteriophage Lambda

    Ding, Hui; Luo, Liao-Fu; Lin, Hao

    2011-02-01

    According to the chemical kinetic model of lysogeny/lysis switch in Escherichia coli (E. coli) infected by bacteriophage λ, the entropy production rates of steady states are calculated. The results show that the lysogenic state has lower entropy production rate than lytic state, which provides an explanation on why the lysogenic state of λ phage is so stable. We also notice that the entropy production rates of both lysogenic state and lytic state are lower than that of saddle-point and bifurcation state, which is consistent with the principle of minimum entropy production for living organism in nonequilibrium stationary state. Subsequently, the relations between CI and Cro degradation rates at two bifurcations and the changes of entropy production rate with CI and Cro degradation are deduced. The theory and method can be used to calculate entropy change in other molecular network.

  14. Vitamin D3 and Monomethyl Fumarate Enhance Natural Killer Cell Lysis of Dendritic Cells and Ameliorate the Clinical Score in Mice Suffering from Experimental Autoimmune Encephalomyelitis

    Zaidoon Al-Jaderi

    2015-11-01

    Full Text Available Experimental autoimmune encephalomyelitis (EAE is a CD4+ T cell mediated inflammatory demyelinating disease that is induced in mice by administration of peptides derived from myelin proteins. We developed EAE in SJL mice by administration of PLP139–151 peptide. The effect of treating these mice with 1α,25-Dihydroxyvitamin D3 (vitamin D3, or with monomethyl fumarate (MMF was then examined. We observed that both vitamin D3 and MMF inhibited and/or prevented EAE in these mice. These findings were corroborated with isolating natural killer (NK cells from vitamin D3-treated or MMF-treated EAE mice that lysed immature or mature dendritic cells. The results support and extend other findings indicating that an important mechanism of action for drugs used to treat multiple sclerosis (MS is to enhance NK cell lysis of dendritic cells.

  15. Vitamin D₃ and monomethyl fumarate enhance natural killer cell lysis of dendritic cells and ameliorate the clinical score in mice suffering from experimental autoimmune encephalomyelitis.

    Al-Jaderi, Zaidoon; Maghazachi, Azzam A

    2015-11-01

    Experimental autoimmune encephalomyelitis (EAE) is a CD4⁺ T cell mediated inflammatory demyelinating disease that is induced in mice by administration of peptides derived from myelin proteins. We developed EAE in SJL mice by administration of PLP139-151 peptide. The effect of treating these mice with 1α,25-Dihydroxyvitamin D₃ (vitamin D₃), or with monomethyl fumarate (MMF) was then examined. We observed that both vitamin D₃ and MMF inhibited and/or prevented EAE in these mice. These findings were corroborated with isolating natural killer (NK) cells from vitamin D₃-treated or MMF-treated EAE mice that lysed immature or mature dendritic cells. The results support and extend other findings indicating that an important mechanism of action for drugs used to treat multiple sclerosis (MS) is to enhance NK cell lysis of dendritic cells. PMID:26580651

  16. The impact of lactic acid bacteria on sourdough fermentation

    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.

  17. INFLUENCE OF MEAT MATURATION TO THE PRESENCE OF COLIFORM BACTERIA

    Ľubomír Lopašovský

    2012-12-01

    Full Text Available Normal 0 21 false false false SK JA X-NONE The aim of our study was detection of coliforms bacteria and pH changes in the process of beef maturation. The number of coliforms bacteria were lower as 1 log cfu.g-1 in four samples and the highest coliforms bacteria count was 3.1 log cfu.g-1 after 1-st week of meat maturation. Average number of coliforms bacteria was lower as 1.43 log cfu.g-1.  The pH values of meat varied from 5.5 to 6.1 after 1-st week. Average value of pH was 5.75.  The number of coliforms bacteria were from 2.61 log cfu.g-1 to 3.35 log cfu.g-1 after 2-nd week of meat maturation. Average number of coliforms bacteria was 3.17 log cfu.g-1. The pH values of meat were from 6.0 to 6.2 after 2-nd week of meat maturation. Average value of pH was 6.05. doi:10.5219/181

  18. T4噬菌体的组装、感染及细胞裂解%Assembly, Infection and Cell Lysis of Bacteriophage T4

    颜晨; 逯凯; 任慧英

    2011-01-01

    To further develop and utilize T4 phage display and phage therapy, and open the broader prospect for the progress in study of T4 phage, the important components of T4 phage particles was analyzed by molecular biology techniques, such as the head, the tail and the basement. The protein composition of these structure were confirmed. DNA packing which was an important part in the assembly of T4 phage particle was described in detail. Not only the phenomenon of infection and lysis, but also the superinfection exclusion and lysis inhibition in T4 life cycles introduced with molecular mechanism and impact factor. The assembly and infection mechanism of T4 phage would be known much better by these research.%为深入开发利用T4噬菌体展示系统及T4噬菌体的临床细菌病治疗,应用现代各种分子生物学手段,在蛋白分子和组成结构上对T4噬菌体颗粒的各个重要组成部分进行分析,例如头部、尾部和尾板,描述了其蛋白构成和各种影响因子,并着重介绍了在噬菌体装配中最为重要的DNA的包装.同时针对噬菌体T4的感染与超感染免疫性和感染所导致的细胞裂解和裂解抑制等方面,介绍了这些现象发生的分子机制和影响因素.以期对T4噬菌体的分子装配和侵染机制有更为深刻的了解.

  19. In black South Africans from rural and urban communities, the 4G/5G PAI-1 polymorphism influences PAI-1 activity, but not plasma clot lysis time.

    Zelda de Lange

    Full Text Available Data on genetic and environmental factors influencing PAI-1 levels and their consequent effect on clot lysis in black African populations are limited. We identified polymorphisms in the promoter area of the PAI-1 gene and determined their influence on PAI-1act levels and plasma clot lysis time (CLT. We also describe gene-environment interactions and the effect of urbanisation. Data from 2010 apparently healthy urban and rural black participants from the South African arm of the PURE study were cross-sectionally analysed. The 5G allele frequency of the 4G/5G polymorphism was 0.85. PAI-1act increased across genotypes in the urban subgroup (p = 0.009 but not significantly in the rural subgroup, while CLT did not differ across genotypes. Significant interaction terms were found between the 4G/5G polymorphism and BMI, waist circumference and triglycerides in determining PAI-1act, and between the 4G/5G polymorphism and fibrinogen and fibrinogen gamma prime in determining CLT. The C428T and G429A polymorphisms did not show direct relationships with PAI-1act or CLT but they did influence the association of other environmental factors with PAI-1act and CLT. Several of these interactions differed significantly between rural and urban subgroups, particularly in individuals harbouring the mutant alleles. In conclusion, although the 4G/5G polymorphism significantly affected PAI-1act, it contributed less than 1% to the PAI-1act variance. (Central obesity was the biggest contributor to PAI-1act variance (12.5%. Urbanisation significantly influenced the effect of the 4G/5G polymorphism on PAI-1act as well as gene-environment interactions for the C428T and G429A genotypes in determining PAI-1act and CLT.

  20. Associations of Europium(III) with gram-negative bacteria

    Full text of publication follows: Migration of radionuclides in the environment is greatly affected by bacteria. Gram-negative bacteria are ubiquitous in the environment and can preferentially bind radionuclides because of the presence of the cell envelop consisting of two membrane bilayers with an intervening thin peptidoglycan layer, where carboxyl and phosphate functional groups are mainly involved in metal cation adsorption. In this study, we investigated the association of Eu(III) with four Gram-negative bacteria Pseudomonas fluorescens, Alcaligenes faecalis, Shewanella putrefaciens, and Paracoccus denitrificans. Europium(III) is a good analogue of Am(III) and Cm(III). The association of Eu(III) with the bacteria were determined by time-resolved laser-induced fluorescence spectroscopy (TRLFS). The kinetics study showed that the Eu(III) adsorption on the bacteria proceeded rapidly. The Eu(III) adsorption on P. fluorescens at pH 3, A. faecalis and P. denitrificans at pHs 3, 4, and 5, and S. putrefaciens at pHs 4 and 5 reached a maximum within 5 minutes after contact. For P. denitrificans, the percent adsorption of Eu(III) decreased after the maximum percent adsorption was attained, which suggests the existence of exudates with an affinity with Eu(III). TRLFS showed that the coordination of Eu(III) on these bacteria is multi-dentate through an inner-spherical process. The ligand field of Eu(III) on P. denitrificans was as strong as the ones observed for halo-philic microorganisms, while that of P. fluorescens, A. faecalis, and S. putrefaciens was the typical one observed for non-halo-philic microorganisms. The coordination environment of Eu(III) on the bacteria differed from each other, though they are categorized as Gram-negative bacteria with the similar cell wall components. (authors)

  1. Programmed survival of soil bacteria

    Jensen, Lars Bogø; Molin, Søren; Sternberg, Claus;

    Biological containment systems have been developed for Pseudomonas putida and related soil bacteria. The systems are based on combinations of lethal genes and regulated gene expression. Two types of killing function have been employed: 1) A membrane protein interfering with the membrane potential...

  2. Role of Bacteria in Oncogenesis

    Chang, Alicia H; Parsonnet, Julie

    2010-01-01

    Summary: Although scientific knowledge in viral oncology has exploded in the 20th century, the role of bacteria as mediators of oncogenesis has been less well elucidated. Understanding bacterial carcinogenesis has become increasingly important as a possible means of cancer prevention. This review summarizes clinical, epidemiological, and experimental evidence as well as possible mechanisms of bacterial induction of or protection from malignancy.

  3. Engineering robust lactic acid bacteria

    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,

  4. Amoeba-resisting bacteria found in multilamellar bodies secreted by Dictyostelium discoideum: social amoebae can also package bacteria.

    Paquet, Valérie E; Charette, Steve J

    2016-03-01

    Many bacteria can resist phagocytic digestion by various protozoa. Some of these bacteria (all human pathogens) are known to be packaged in multilamellar bodies produced in the phagocytic pathway of the protozoa and that are secreted into the extracellular milieu. Packaged bacteria are protected from harsh conditions, and the packaging process is suspected to promote bacterial persistence in the environment. To date, only a limited number of protozoa, belonging to free-living amoebae and ciliates, have been shown to perform bacteria packaging. It is still unknown if social amoebae can do bacteria packaging. The link between the capacity of 136 bacterial isolates to resist the grazing of the social amoeba Dictyostelium discoideum and to be packaged by this amoeba was investigated in the present study. The 45 bacterial isolates displaying a resisting phenotype were tested for their capacity to be packaged. A total of seven isolates from Cupriavidus, Micrococcus, Microbacterium and Rathayibacter genera seemed to be packaged and secreted by D. discoideum based on immunofluorescence results. Electron microscopy confirmed that the Cupriavidus and Rathayibacter isolates were formally packaged. These results show that social amoebae can package some bacteria from the environment revealing a new aspect of microbial ecology. PMID:26862140

  5. The Population and Evolutionary Dynamics of Homologous Gene Recombination in Bacteria

    Levin, Bruce R.; Cornejo, Omar E

    2009-01-01

    In bacteria, recombination is a rare event, not a part of the reproductive process. Nevertheless, recombination—broadly defined to include the acquisition of genes from external sources, i.e., horizontal gene transfer (HGT)—plays a central role as a source of variation for adaptive evolution in many species of bacteria. Much of niche expansion, resistance to antibiotics and other environmental stresses, virulence, and other characteristics that make bacteria interesting and problematic, is ac...

  6. Fuzzy species among recombinogenic bacteria

    Fraser Christophe

    2005-03-01

    Full Text Available Abstract Background It is a matter of ongoing debate whether a universal species concept is possible for bacteria. Indeed, it is not clear whether closely related isolates of bacteria typically form discrete genotypic clusters that can be assigned as species. The most challenging test of whether species can be clearly delineated is provided by analysis of large populations of closely-related, highly recombinogenic, bacteria that colonise the same body site. We have used concatenated sequences of seven house-keeping loci from 770 strains of 11 named Neisseria species, and phylogenetic trees, to investigate whether genotypic clusters can be resolved among these recombinogenic bacteria and, if so, the extent to which they correspond to named species. Results Alleles at individual loci were widely distributed among the named species but this distorting effect of recombination was largely buffered by using concatenated sequences, which resolved clusters corresponding to the three species most numerous in the sample, N. meningitidis, N. lactamica and N. gonorrhoeae. A few isolates arose from the branch that separated N. meningitidis from N. lactamica leading us to describe these species as 'fuzzy'. Conclusion A multilocus approach using large samples of closely related isolates delineates species even in the highly recombinogenic human Neisseria where individual loci are inadequate for the task. This approach should be applied by taxonomists to large samples of other groups of closely-related bacteria, and especially to those where species delineation has historically been difficult, to determine whether genotypic clusters can be delineated, and to guide the definition of species.

  7. Study on the total colony of bacteria and coliform group during the production process of sausage%红肠不同生产环节中菌落总数和大肠菌群数量变化规律初步研究

    马春华; 陶荣

    2013-01-01

      目的研究红肠不同生产环节、不同环境中菌落总数和大肠菌群数的变化规律。方法用国标方法检测红肠各个工序不同环境中的菌落总数和大肠菌群数,并用统计学软件 SSPS 处理结果。结果建立菌落总数和大肠菌群数量变化规律模型。红肠加工不同环境中菌落总数变化规律的非线性拟合方程为0.4822 y 1768.952=e-x+27.6370.856 x+;24.365大肠菌群数变化规律的非线性拟合方程为2 y=-+x 20.9900.968 x+结论本研究对于控制红肠中微生物数量,保证其安全卫生具有重要意义。。%Objective To study the changes of total colony of bacteria and coliform group during the production process of sausage and different environment. Methods The number of total colony of bacteria and coliform group was analysed using the method of national standard, and the data was processed with SPSS software. Results The nonlinear curves about the number of total colony of bacteria and coliform group were 2 y 1 768.952=e-0.482 x+27.637 0.856 x+24.365;and 2 y= - +x 2 , respectively. Conclusion This study 0.990 0.968 x+is important to control the number of total colony of bacteria and coliform group and guarantee safety and sa-nitation of sausage.

  8. Physico-chemical factors and bacteria in fish ponds

    Jun, X.; Xiuzheng, F.; Tongbing, Y.

    2000-01-01

    Analyses of pond water and mud samples show that nitrifying bacteria (including ammonifying bacteria, nitrite bacteria, nitrobacteria and denitrifying bacteria) are in general closely correlated with various physico-chemical factors, ammonifying bacteria are mainly correlated with dissolved oxygen; denitrifying bacteria are inversely correlated with phosphorus; nitrite bacteria are closely correlated with nitrites, nitrobacteria are inversely correlated with ammoniac nitrogen. The nitrifying ...

  9. Low field orientation magnetic separation methods for magnetotactic bacteria

    Microbial biomineralisation of iron often results in a biomass that is magnetic and can be separated from water systems by the application of a magnetic field. Magnetotactic bacteria form magnetic membrane bound crystals within their structure, generally of magnetite. In nature, this enables magnetotactic bacteria to orientate themselves with respect to the local geomagnetic field. The bacteria then migrate with flagellar driven motion towards their preferred environment. This property has been harnessed to produce a process in which metal loaded magnetotactic bacteria can be recovered from a waste stream. This process is known as orientation magnetic separation. Several methods exist which permit the unique magnetic properties of individual magnetotactic bacteria to be studied, such as U-turn analysis, transmission electron microscopy and single wire cell studies. In this work an extension of U-turn analysis was developed. The bacteria were rendered non-motile by the addition of specific metal ions and the resulting 'flip time' which occurs during a field reversal enabled the magnetic moment of individual bacteria to be determined. This method proved to be much faster and more accurate than previous methods. For a successful process to be developed, large scale culturing of magnetotactic bacteria is required Experiments showed that culture vessel geometry was an important factor for high-density growth. Despite intensive studies reproducible culturing at volumes exceeding one litre was not achieved. This work showed that numerous metal ions rendered magnetotactic bacteria non-motile at concentrations below 10 ppm. Sequential adaptation raised typical levels to in excess of 100 ppm for a number of ions. such as zinc and tin. However, specific ions. such as copper or nickel, remained motility inhibiting at lower concentrations. To achieve separation using orientation magnetic separation, motile, field susceptible MTB are required. Despite successful adaptation, the

  10. Method and apparatus for processing algae

    Chew, Geoffrey; Reich, Alton J.; Dykes, Jr., H. Waite; Di Salvo, Roberto

    2012-07-03

    Methods and apparatus for processing algae are described in which a hydrophilic ionic liquid is used to lyse algae cells. The lysate separates into at least two layers including a lipid-containing hydrophobic layer and an ionic liquid-containing hydrophilic layer. A salt or salt solution may be used to remove water from the ionic liquid-containing layer before the ionic liquid is reused. The used salt may also be dried and/or concentrated and reused. The method can operate at relatively low lysis, processing, and recycling temperatures, which minimizes the environmental impact of algae processing while providing reusable biofuels and other useful products.

  11. Smokeless Tobacco May Contain Potentially Harmful Bacteria

    ... 160769.html Smokeless Tobacco May Contain Potentially Harmful Bacteria Infections, diarrhea and vomiting are possible consequences, FDA ... products can harbor several species of potentially harmful bacteria, researchers warn. Two types in particular -- Bacillus licheniformis ...

  12. Killer Pigments in Bacteria: An Ecological Nightmare.

    Benathen, Isaiah A.; Saccardi, Marion

    2000-01-01

    Describes an alternative to teaching ecology by using bacteria to test competitor survival. Students observe a time-dependent selective killing of other unrelated bacteria by Pseudomonas aeruginosa. (SAH)

  13. Techniques for Reduction and Biomineralization of Radioactive Uranium by Bacteria

    A new thing revealed by this study was a formation of 'ningyoite', which was made as a new mineral when phosphorus component added into the uranium bioreduction process. In addition, a main sulfide mineral formed by sulfate-reducing bacteria was mackinawite which can incorporate much of uranium as coexisting with metal impurities such as manganese or nickel elements

  14. Killing of Bacteria by Copper Surfaces Involves Dissolved Copper▿

    Molteni, Cristina; Abicht, Helge K.; Solioz, Marc

    2010-01-01

    Bacteria are rapidly killed on copper surfaces. However, the mechanism of this process remains unclear. Using Enterococcus hirae, the effect of inactivation of copper homeostatic genes and of medium compositions on survival and copper dissolution was tested. The results support a role for dissolved copper ions in killing.

  15. Can the excretion of metabolites by bacteria be manipulated?

    Konings, Wil N.; Poolman, Bert; Driessen, Arnold J.M.

    1992-01-01

    Bacteria can release metabolites into the environment by various mechanisms. Excretion may occur by passive diffusion or by the reversal of the uptake process when the internal concentration of the metabolite exceeds the thermodynamic equilibrium level. In other cases, solutes are excreted against t

  16. Reduction of Polymeric Azo and Nitro Dyes by Intestinal Bacteria

    Brown, Joseph P.

    1981-01-01

    The O2-sensitive reduction of high-molecular-weight aromatic azo and nitro dyes by intestinal bacteria appears to be mediated by low-molecular-weight electron carriers with Eo′ = −200 to −350 mV. This process may allow the design of polymeric azo prodrugs for specific release of certain aromatic amines in the colon.

  17. Re-engineering bacteria for ethanol production

    Yomano, Lorraine P; York, Sean W; Zhou, Shengde; Shanmugam, Keelnatham; Ingram, Lonnie O

    2014-05-06

    The invention provides recombinant bacteria, which comprise a full complement of heterologous ethanol production genes. Expression of the full complement of heterologous ethanol production genes causes the recombinant bacteria to produce ethanol as the primary fermentation product when grown in mineral salts medium, without the addition of complex nutrients. Methods for producing the recombinant bacteria and methods for producing ethanol using the recombinant bacteria are also disclosed.

  18. IDENTIFICATION OF BACTERIA IN LATEX PAINTS

    Rojas, J

    2008-01-01

    The bacteria are prokaryote organisms with a high capacity to colonize many types of habits. This research was developed with the object to identify extremophiles bacteria presents in latex paint. The bacteria were cultivated in culture mediums TSA, Blood Agar, Mc Conkey and finally the biochemical proof API-NF® for bacteria's isolation and identification, respectively. Characterization showed bacterial profile of Pasteurella sp. Hypothesis that could be found extremophiles bac...

  19. Genetics of Lactic Acid Bacteria

    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).

  20. Aggregation Patterns in Stressed Bacteria

    Tsimring, L S; Aranson, I S; Ben-Jacob, E; Cohen, I; Shochet, O; Tsimring, Lev; Levine, Herbert; Aranson, Igor; Ben-Jacob, Eshel; Cohen, Inon; Shochet, Ofer

    1995-01-01

    We study the formation of spot patterns seen in a variety of bacterial species when the bacteria are subjected to oxidative stress due to hazardous byproducts of respiration. Our approach consists of coupling the cell density field to a chemoattractant concentration as well as to nutrient and waste fields. The latter serves as a triggering field for emission of chemoattractant. Important elements in the proposed model include the propagation of a front of motile bacteria radially outward form an initial site, a Turing instability of the uniformly dense state and a reduction of motility for cells sufficiently far behind the front. The wide variety of patterns seen in the experiments is explained as being due the variation of the details of the initiation of the chemoattractant emission as well as the transition to a non-motile phase.

  1. LACTIC ACID BACTERIA: PROBIOTIC APPLICATIONS

    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.

  2. Dissipative Shocks behind Bacteria Gliding

    Virga, Epifanio G

    2014-01-01

    Gliding is a means of locomotion on rigid substrates utilized by a number of bacteria includingmyxobacteria and cyanobacteria. One of the hypotheses advanced to explain this motility mechanism hinges on the role played by the slime filaments continuously extruded from gliding bacteria. This paper solves in full a non-linear mechanical theory that treats as dissipative shocks both the point where the extruded slime filament comes in contact with the substrate, called the filament's foot, and the pore on the bacterium outer surface from where the filament is ejected. We prove that kinematic compatibility for shock propagation requires that the bacterium uniform gliding velocity (relative to the substrate) and the slime ejecting velocity (relative to the bacterium) must be equal, a coincidence that seems to have already been observed.

  3. Mechanistic modeling of biocorrosion caused by biofilms of sulfate reducing bacteria and acid producing bacteria.

    Xu, Dake; Li, Yingchao; Gu, Tingyue

    2016-08-01

    Biocorrosion is also known as microbiologically influenced corrosion (MIC). Most anaerobic MIC cases can be classified into two major types. Type I MIC involves non-oxygen oxidants such as sulfate and nitrate that require biocatalysis for their reduction in the cytoplasm of microbes such as sulfate reducing bacteria (SRB) and nitrate reducing bacteria (NRB). This means that the extracellular electrons from the oxidation of metal such as iron must be transported across cell walls into the cytoplasm. Type II MIC involves oxidants such as protons that are secreted by microbes such as acid producing bacteria (APB). The biofilms in this case supply the locally high concentrations of oxidants that are corrosive without biocatalysis. This work describes a mechanistic model that is based on the biocatalytic cathodic sulfate reduction (BCSR) theory. The model utilizes charge transfer and mass transfer concepts to describe the SRB biocorrosion process. The model also includes a mechanism to describe APB attack based on the local acidic pH at a pit bottom. A pitting prediction software package has been created based on the mechanisms. It predicts long-term pitting rates and worst-case scenarios after calibration using SRB short-term pit depth data. Various parameters can be investigated through computer simulation. PMID:27071053

  4. Box-shaped halophilic bacteria.

    Javor, B; Requadt, C; Stoeckenius, W

    1982-01-01

    Three morphologically similar strains of halophilic, box-shaped procaryotes have been isolated from brines collected in the Sinai, Baja California (Mexico), and southern California (United States). Although the isolates in their morphology resemble Walsby's square bacteria, which are a dominant morphological type in the Red Sea and Baja California brines, they are probably not identical to them. The cells show the general characteristics of extreme halophiles and archaebacteria. They contain ...

  5. Folate Production by Probiotic Bacteria

    Stefano Raimondi; Alberto Amaretti; Maddalena Rossi

    2011-01-01

    Probiotic bacteria, mostly belonging to the genera Lactobacillus and Bifidobacterium, confer a number of health benefits to the host, including vitamin production. With the aim to produce folate-enriched fermented products and/or develop probiotic supplements that accomplish folate biosynthesis in vivo within the colon, bifidobacteria and lactobacilli have been extensively studied for their capability to produce this vitamin. On the basis of physiological studies and genome analysis, wild-typ...

  6. Magnetotactic Bacteria from Extreme Environments

    Lefèvre, Christopher T; Dennis A. Bazylinski

    2013-01-01

    Magnetotactic bacteria (MTB) represent a diverse collection of motile prokaryotes that biomineralize intracellular, membrane-bounded, tens-of-nanometer-sized crystals of a magnetic mineral called magnetosomes. Magnetosome minerals consist of either magnetite (Fe3O4) or greigite (Fe3S4) and cause cells to align along the Earth’s geomagnetic field lines as they swim, a trait called magnetotaxis. MTB are known to mainly inhabit the oxic–anoxic interface (OAI) in water columns or sediments of aqu...

  7. A empiric expression to interpret the approximation of λ cI phages to E. coli C600 bacteria

    In general the process of adsorption of phages to bacteria is considered in the bibliography as an statistical process. In this work we use an empiric expression which allows to interpret the approximation of λcI pages to E. coli C600 bacteria. This expression introduces some changes respect to a pure statistical description of the approximation process. (Author) 26 refs

  8. Bacteria interfere with A-actinomycetemcomitans colonization

    Teughels, Wim; Haake, S. Kinder; Sliepen, Isabelle; Pauwels, Martine; Van Eldere, Johan; Cassiman, Jean-Jacques; Quirynen, Marc

    2007-01-01

    It is known that beneficial bacteria can suppress the emergence of pathogenic bacteria, particularly in the gastrointestinal tract. This study examined the potential for a similar suppression of Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans colonization of epithelial cells, due to its potential relevance in periodontal diseases. Seven presumed beneficial bacteria were examined for their ability to interfere, exclude, or displace A. actinomycetemcomitans from epithelial cells...

  9. Laser-Based Identification of Pathogenic Bacteria

    Rehse, Steven J.

    2009-01-01

    Bacteria are ubiquitous in our world. From our homes, to our work environment, to our own bodies, bacteria are the omnipresent although often unobserved companions to human life. Physicists are typically untroubled professionally by the presence of these bacteria, as their study usually falls safely outside the realm of our typical domain. In the…

  10. Magnetotactic bacteria at the geomagnetic equator

    Magnetotatic bacteria are observed in freshwater and marine sediments of Fortaleza, Brazil, situated close to the geomagnetic equator. Both South-seeking and North-seeking bacteria are present in roughly equal numbers in the same samples. This observation is consistent with the hypothesis that the vertical component of the geomagnetic field selects the predominant polarity type among magnetotactic bacteria in natural environments. (Author)

  11. Drosophila lifespan enhancement by exogenous bacteria

    Brummel, Ted; Ching, Alisa; Seroude, Laurent; Simon, Anne F.; Benzer, Seymour

    2004-01-01

    We researched the lifespan of Drosophila under axenic conditions compared with customary procedure. The experiments revealed that the presence of bacteria during the first week of adult life can enhance lifespan, despite unchanged food intake. Later in life, the presence of bacteria can reduce lifespan. Certain long-lived mutants react in different ways, indicating an interplay between bacteria and longevity-enhancing genes.

  12. Can Pulp Fibroblasts Kill Cariogenic Bacteria? Role of Complement Activation.

    Jeanneau, C; Rufas, P; Rombouts, C; Giraud, T; Dejou, J; About, I

    2015-12-01

    Complement system activation has been shown to be involved in inflammation and regeneration processes that can be observed within the dental pulp after moderate carious decay. Studies simulating carious injuries in vitro have shown that when human pulp fibroblasts are stimulated by lipoteichoic acid (LTA), they synthetize all complement components. Complement activation leads to the formation of the membrane attack complex (MAC), which is known for its bacterial lytic effect. This work was designed to find out whether human pulp fibroblasts can kill Streptococcus mutans and Streptococcus sanguinis via complement activation. First, histological staining of carious tooth sections showed that the presence of S. mutans correlated with an intense MAC staining. Next, to simulate bacterial infection in vitro, human pulp fibroblasts were incubated in serum-free medium with LTA. Quantification by an enzymatic assay showed a significant increase of MAC formation on bacteria grown in this LTA-conditioned medium. To determine whether the MAC produced by pulp fibroblasts was functional, bacteria sensitivity to LTA-conditioned medium was evaluated using agar well diffusion assay and succinyl dehydrogenase (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide [MTT]) assay. Both assays showed that S. mutans and S. sanguinis were sensitive to LTA-conditioned medium. Finally, to evaluate whether MAC formation on cariogenic bacteria, by pulp fibroblasts, can be directly induced by the presence of these bacteria, a specific coculture model of human pulp fibroblasts and bacteria was developed. Immunofluorescence revealed an intense MAC labeling on bacteria after direct contact with pulp fibroblasts. The observed MAC formation and its lethal effects were significantly reduced when CD59, an inhibitor of MAC formation, was added. Our findings demonstrate that the MAC produced by LTA-stimulated pulp fibroblasts is functional and can kill S. mutans and S. sanguinis. Taken together

  13. A mathematical model and analytical solution for the fixation of bacteria in biogrout

    Van Wijngaarden, W.K.; Vermolen, F.J.; Van Meurs, G.A.M.; Vuik, C.

    2012-01-01

    Biogrout is a new method for soil reinforcement, which is based on microbialinduced carbonate precipitation. Bacteria and reactants are flushed through the soil, resulting in calcium carbonate precipitation and consequent soil reinforcement. Bacteria are crucially important in the Biogrout process s

  14. Suscetibilidade à azitromicina de isolados bacterianos de processos infecciosos em cães e gatos Susceptibility to azithromycin of bacteria isolated from infectious processes in dogs and cats

    Ingrid A. Pereira

    2009-02-01

    Full Text Available O presente estudo avaliou o perfil de suscetibilidade à azitromicina de patógenos bacterianos prevalentes em diferentes sítios infecciosos de animais de companhia. Adicionalmente, foram estudados o perfil de atividade in vitro de azitromicina contra esses patógenos e sua concentração inibitória mínima (CIM. Testes como a difusão em disco e a microdiluição em caldo detectaram resistência respectivamente em 48,6% e 55% dos isolados de Staphylococcus spp. e em 55,3% e 72,7% dos bastonetes Gram-negativos. A CIM50 para S. aureus foi 4,0mg/mL, para S. intermedius foi de 1,0mg/mL, para Staphylococcus spp. coagulase-negativas foi de e"512mg/mL e para bastonetes Gram-negativos foi de 256mg/mL. Quinze por cento (9/60 dos isolados oxacilina-resistente e multidroga-resistentes, mecA-positivos, de Staphylococcus spp. apresentaram também resistência à azitromicina. A disseminação de bactérias multidroga-resistentes aponta para a necessidade da avaliação da atividade antimicrobiana para selecionar o fármaco mais indicado e, assim, minimizar falhas terapêuticas na conduta clínica veterinária.The susceptibility pattern to azithromycin of bacterial pathogens from various infectious sites, and the in vitro activity and minimum inhibitory concentration (MIC of azithromycin were studied. Tests such as disc diffusion and broth microdilution detected respectively 48.6% and 55% of resistant Staphylococcus spp., and 55.3% and 72.7% resistant gram-negative rods. MIC50 for S. aureus was 4.0mg/mL, that for S. intermedius was 1.0mg/mL, for coagulase-negative Staphylococcus e"512mg/mL, and for gram-negative rods 256mg/mL. Fifteen percent (9/60 of oxacilin-resistant, multidrug-resistant and mecA-positive Staphylococcus spp. isolates were also azithromycin resistant. The dissemination of multidrug resistant bacteria points out to the need of antimicrobial evaluation activity in order to select the best indicated drug and thus minimizing therapeutic

  15. Biophysical Evaluation of Food Decontamination Effects on Tissue and Bacteria

    Andersen, Ann Zahle; Duelund, Lars; Brewer, Jonathan R.;

    2011-01-01

    Traditionally, the effects and efficiency of food surface decontamination processes, such as chlorine washing, radiation, or heating, have been evaluated by sensoric analysis and colony-forming unit (CFU) counts of surface swabs or carcass rinses. These methods suffice when determining probable...... both food surface and bacteria upon surface decontamination by SonoSteam®. SonoSteam® is a recently developed method of food surface decontamination, which employs steam and ultrasound for effective heat transfer and short treatment times, resulting in significant reduction in surface bacteria. We...... employ differential scanning calorimetry, second harmonics generation imaging microscopy, two-photon fluorescence microscopy, and green fluorescence protein-expressing bacteria and compare our results with those obtained by traditional methods of food quality and safety evaluations. Our results show that...

  16. SACCHARIFICATION OF CORNCOB USING CELLULOLYTIC BACTERIA FOR BIOETHANOL PRODUCTION

    TITI CANDRA SUNARTI

    2010-08-01

    Full Text Available The use of cellulose degrading enzyme (cellulases for hydrolysis of lignocellulosic material is a part of bioethanol production process. In this experiment, delignified corncob, its cellulose fraction and alpha cellulose were used as substrates to produce fermentable sugar by using three local isolates of celluloytic bacteria (C5-1, C4-4, C11-1 and Cmix ; mixed cultures of three isolates, and Saccharomyces cereviseae to produce ethanol. The results showed that all isolates of cellulolytic bacteria can grow on cellulose fraction better than on delignified corncob, and alpha cellulose. The highest hydrolytic activity produced from cellulose fraction was by isolate C4-4, which liberated 3.50 g/l of total sugar. Ethanol can be produced by mixed culture of bacteria and yeast, but because of competitive growth, the fermentation only produced 0.39-0.47 g/l of ethanol.

  17. Effect of calcifying bacteria on permeation properties of concrete structures.

    Achal, V; Mukherjee, A; Reddy, M S

    2011-09-01

    Microbially enhanced calcite precipitation on concrete or mortar has become an important area of research regarding construction materials. This study examined the effect of calcite precipitation induced by Sporosarcina pasteurii (Bp M-3) on parameters affecting the durability of concrete or mortar. An inexpensive industrial waste, corn steep liquor (CSL), from starch industry was used as nutrient source for the growth of bacteria and calcite production, and the results obtained with CSL were compared with those of the standard commercial medium. Bacterial deposition of a layer of calcite on the surface of the specimens resulted in substantial decrease of water uptake, permeability, and chloride penetration compared with control specimens without bacteria. The results obtained with CSL medium were comparable to those obtained with standard medium, indicating the economization of the biocalcification process. The results suggest that calcifying bacteria play an important role in enhancing the durability of concrete structures. PMID:21104104

  18. ISOLATION AND IDENTIFICATION OF ACR YLAMIDE DEGRADING BACTERIA FROM SOIL

    Nidhi Jain

    2013-02-01

    Full Text Available Acrylamide is an aliphatic amide, which is produced by industrial processes and during heating of food. It is neurotoxic and a suspected carcinogen. In the present study an attempt was made to isolate acrylamide degrading bacteria from soil. The optimum growth conditions and physiological characteristics for the isolated acrylamide degrading bacteria were investigated. The isolated bacterium was identified as Bacillus clausii strain 1779 based on full 16S rRNA molecular phylogeny. The bacteria can degrade 800 mg l-1acrylamide after eight days of incubation with concomitant cell growth. In addition to above, it also grows optimally at a concentration of acrylamide between 500-2000 mg l-1between pH 8-10 and temperature and 25 – 45 0C. Thus the isolate would be useful in the bioremediation of environment from acrylamide in alkali conditions.

  19. A versatile plasmonic thermogel for disinfection of antimicrobial resistant bacteria.

    Abdou Mohamed, Mohamed A; Raeesi, Vahid; Turner, Patricia V; Rebbapragada, Anu; Banks, Kate; Chan, Warren C W

    2016-08-01

    The increasing occurrence of antimicrobial resistance among bacteria is a global problem that requires the development of alternative techniques to eradicate these superbugs. Herein, we used a combination of thermosensitive biocompatible polymer and gold nanorods to specifically deliver, preserve and confine heat to the area of interest. Our data demonstrates that this technique can be used to kill both Gram positive and Gram negative antimicrobial resistant bacteria in vitro. Our approach significantly reduces the antimicrobial resistant bacteria load in experimentally infected wounds by 98% without harming the surrounding tissues. More importantly, this polymer-nanocomposite can be prepared easily and applied to the wounds, can generate heat using a hand-held laser device, is safe for the operator, and does not have any adverse effects on the wound tissue and healing process. PMID:27174687

  20. Algae-bacteria interactions: Evolution, ecology and emerging applications.

    Ramanan, Rishiram; Kim, Byung-Hyuk; Cho, Dae-Hyun; Oh, Hee-Mock; Kim, Hee-Sik

    2016-01-01

    Algae and bacteria have coexisted ever since the early stages of evolution. This coevolution has revolutionized life on earth in many aspects. Algae and bacteria together influence ecosystems as varied as deep seas to lichens and represent all conceivable modes of interactions - from mutualism to parasitism. Several studies have shown that algae and bacteria synergistically affect each other's physiology and metabolism, a classic case being algae-roseobacter interaction. These interactions are ubiquitous and define the primary productivity in most ecosystems. In recent years, algae have received much attention for industrial exploitation but their interaction with bacteria is often considered a contamination during commercialization. A few recent studies have shown that bacteria not only enhance algal growth but also help in flocculation, both essential processes in algal biotechnology. Hence, there is a need to understand these interactions from an evolutionary and ecological standpoint, and integrate this understanding for industrial use. Here we reflect on the diversity of such relationships and their associated mechanisms, as well as the habitats that they mutually influence. This review also outlines the role of these interactions in key evolutionary events such as endosymbiosis, besides their ecological role in biogeochemical cycles. Finally, we focus on extending such studies on algal-bacterial interactions to various environmental and bio-technological applications. PMID:26657897

  1. Potential role of bacteria packaging by protozoa in the persistence and transmission of pathogenic bacteria

    Alix M Denoncourt; Paquet, Valérie E.; Charette, Steve J.

    2014-01-01

    Many pathogenic bacteria live in close association with protozoa. These unicellular eukaryotic microorganisms are ubiquitous in various environments. A number of protozoa such as amoebae and ciliates ingest pathogenic bacteria, package them usually in membrane structures, and then release them into the environment. Packaged bacteria are more resistant to various stresses and are more apt to survive than free bacteria. New evidence indicates that protozoa and not bacteria control the packaging...

  2. Social behavior of bacteria: from physics to complex organization

    Ben-Jacob, E.

    2008-10-01

    I describe how bacteria develop complex colonial patterns by utilizing intricate communication capabilities, such as quorum sensing, chemotactic signaling and exchange of genetic information (plasmids) Bacteria do not store genetically all the information required for generating the patterns for all possible environments. Instead, additional information is cooperatively generated as required for the colonial organization to proceed. Each bacterium is, by itself, a biotic autonomous system with its own internal cellular informatics capabilities (storage, processing and assessments of information). These afford the cell certain plasticity to select its response to biochemical messages it receives, including self-alteration and broadcasting messages to initiate alterations in other bacteria. Hence, new features can collectively emerge during self-organization from the intra-cellular level to the whole colony. Collectively bacteria store information, perform decision make decisions (e.g. to sporulate) and even learn from past experience (e.g. exposure to antibiotics)-features we begin to associate with bacterial social behavior and even rudimentary intelligence. I also take Schrdinger’s’ “feeding on negative entropy” criteria further and propose that, in addition organisms have to extract latent information embedded in the environment. By latent information we refer to the non-arbitrary spatio-temporal patterns of regularities and variations that characterize the environmental dynamics. In other words, bacteria must be able to sense the environment and perform internal information processing for thriving on latent information embedded in the complexity of their environment. I then propose that by acting together, bacteria can perform this most elementary cognitive function more efficiently as can be illustrated by their cooperative behavior.

  3. Sulfate reducing bacteria detection in gas pipelines; Deteccao de bacterias redutoras de sulfato em gasodutos

    Lutterbach, Marcia Teresa S.; Oliveira, Ana Lucia C. de; Cavalcanti, Eduardo H. de S. [Instituto Nacional de Tecnologia (INT), Rio de Janeiro, RJ (Brazil). Div. de Corrosao e Degradacao]. E-mails: marciasl@int.gov.br; analucia@int.gov.br; eduardoh@int.gov.br

    2004-07-01

    Microbiology induced corrosion (MIC) process associated with sulfate reducing bacteria (BRS) are one of the most important matter of concern for the oil and gas industry as 77% of failures have been attributed this sort of degradation. Corrosion products found present in gas transportation pipelines, the so-called 'black-powder' problem, are also a nuisance and source of economic losses for the gas industry. According to the literature, the incidence of black-powder can be ascribed to the metabolism of BRS that can be found in the gas environment. Integrity monitoring programs of gas pipelines adopt pigging as an important tool for internal corrosion monitoring. Solid residue such as the black-powder, collected by pigging, as well as the condensed, can be seen as a very valuable samples for microbiological analyses that can be used to detect and quantify bacteria related to the incidence of MIC processes. In the present work results concerning samples collected by pigging and condensed are presented. Small populations of viable BRS have been found in the pipeline. It can be seen that the inclusion of microbiological analyses of solid and liquid residues as a complementary action in the integrity monitoring programs adopted by gas transportation industry can be very helpful on the decision making concerning preventive and corrective actions to be taken in order to maintain the CIM processes under control. (author)

  4. Unconventional lateral gene transfer in extreme thermophilic bacteria

    César, Carolina Elvira; Bricio, Carlos; van Heerden, Esta; Littauer, Dereck; Berenguer, José; Álvarez, Laura

    2011-01-01

    Conjugation and natural competence are two major mechanisms that explain the acquisition of foreign genes throughout bacterial evolution. In recent decades, several studies in model organisms have revealed in great detail the steps involved in such processes. The findings support the idea that the major basis of these mechanisms is essentially similar in all bacteria. However, recent work has pinpointed the existence of new, evolutionarily different processes underlying lateral gene transfer....

  5. Effects of three heavy metals on the bacteria growth kinetics. A bivariate model for toxicological assessment

    Rial, Diego; Vazquez, Jose Antonio; Murado, Miguel Anxo [Instituto de Investigacions Marinas (CSIC), Vigo (ES). Grupo de Reciclado y Valorizacion de Materiales Residuales (REVAL)

    2011-05-15

    The effects of three heavy metals (Co, Ni and Cd) on the growth kinetics of five bacterial strains with different characteristics (Pseudomonas sp., Phaeobacter sp. strain 27-4, Listonella anguillarum, Carnobacterium piscicola and Leuconostoc mesenteroides subsp. lysis) were studied in a batch system. A bivariate model, function of time and dose, is proposed to describe simultaneously all the kinetic profiles obtained by incubating a microorganism at increasing concentrations of individual metals. This model combines the logistic equation for describing growth, with a modification of the cumulative Weibull's function for describing the dose-dependent variations of growth parameters. The comprehensive model thus obtained - which minimizes the effects of the experimental error - was statistically significant in all the studied cases, and it raises doubts about toxicological evaluations that are based on a single growth parameter, especially if it is not obtained from a kinetic equation. In lactic acid bacteria cultures (C. piscicola and L. mesenteroides), Cd induced remarkable differences in yield and time course of characteristic metabolites. A global parameter is defined (ED{sub 50,{tau}}: dose of toxic chemical that reduces the biomass of a culture by 50% compared to that produced by the control at the time corresponding to its semi maximum biomass) that allows comparing toxic effects on growth kinetics using a single value. (orig.)

  6. Antibacterial effect of ultrafine nanodiamond against gram-negative bacteria Escherichia coli

    Chatterjee, Anindita; Perevedentseva, Elena; Jani, Mona; Cheng, Chih-Yuan; Ye, Ying-Siou; Chung, Pei-Hua; Cheng, Chia-Liang

    2015-05-01

    We investigate the antibacterial effect of ultrafine nanodiamond particles with an average size of 5 nm against the gram-negative bacteria Escherichia coli (E. coli). UV-visible, Raman spectroscopy, and scanning electron microscopy (SEM) have been employed to elucidate the nature of the interaction. The influence on bacterial growth was monitored by measuring optical densities of E. coli at 600 nm as a function of time in the presence of carboxylated nanodiamond (cND) particles (100 μg/ml) in highly nutritious liquid Luria-Bertani medium. The SEM images prove that cND particles are attached to the bacterial cell wall surface and some portion of the bacterial cell wall undergoes destruction. Due to the change of the protein structure on the bacterial wall, a small Raman shift in the region of 1400 to 1700 cm-1 was observed when E. coli interacted with cNDs. Raman mapping images show strong evidence of cND attachment at the bacterial cell wall surface. Electrotransformation of E. coli with a fluorescent protein markers experiment demonstrated that the interaction mechanisms are different for E. coli treated with cND particles, E. coli by lysozyme treatment, and E. coli that suffer lysis.

  7. Dynamics of swimming bacteria at complex interfaces

    Lopez, Diego

    2014-01-01

    Flagellated bacteria exploiting helical propulsion are known to swim along circular trajectories near surfaces. Fluid dynamics predicts this circular motion to be clockwise (CW) above a rigid surface (when viewed from inside the fluid) and counter-clockwise (CCW) below a free surface. Recent experimental investigations showed that complex physicochemical processes at the nearby surface could lead to a change in the direction of rotation, both at solid surfaces absorbing slip-inducing polymers and interfaces covered with surfactants. Motivated by these results, we use a far-field hydrodynamic model to predict the kinematics of swimming near three types of interfaces: clean fluid-fluid interface, slipping rigid wall, and a fluid interface covered by incompressible surfactants. Representing the helical swimmer by a superposition of hydrodynamic singularities, we first show that in all cases the surfaces reorient the swimmer parallel to the surface and attract it, both of which are a consequence of the Stokes dip...

  8. Bacteria and bioremediation of marine oil spills

    Virtually all marine ecosystems harbor indigenous hydrocarbon-degrading bacteria. These hydrocarbon degraders comprise less than one percent of the bacterial community in unpolluted environments, but generally increase to one to ten percent following petroleum contamination. Various hydrocarbons are degraded by these microorganisms at different rates, so there is an evolution in the residual hydrocarbon mixture, and some hydrocarbons and asphaltic petroleum hydrocarbons remain undegraded. Fortunately, these persistent petroleum pollutants are, for the most part, insoluble or are bound to solids; hence they are not biologically available and therefore not toxic to marine organisms. Carbon dioxide, water, and cellular biomass produced by the microorganisms from the degradable hydrocarbons may be consumed by detrital feeders and comprise the end products of the natural biological degradation process. Bioremediation attempts to accelerate the natural hydrocarbon degradation rates by overcoming factors that limit bacterial hydrocarbon degrading activities

  9. Why bacteria are smaller in the epilimnion than in the hypolimnion? A hypothesis comparing temperate and tropical lakes

    Roberto Bertoni

    2012-01-01

    Full Text Available Bacterial size and morphology are controlled by several factors including predation, viral lysis, UV radiation, and inorganic nutrients. We observed that bacterial biovolume from the hypolimnion of two oligotrophic lakes is larger than that of bacteria living in the layer from surface to 20 m, roughly corresponding to the euphotic/epilimnetic zone. One lake is located in the temperate region at low altitude (Lake Maggiore, Northern Italy and the other in the tropical region at high altitude (Lake Alchichica, Mexico. The two lakes differ in oxygen, phosphorus and nitrogen concentrations and in the temperature of water column. If we consider the two lakes separately, we risk reducing the explanation of bacterial size variation in the water column to merely regional factors. Comparing the two lakes, can we gather a more general explanation for bacterial biovolume variation. The results showed that small bacteria dominate in the oxygenated, P-limited epilimnetic waters of both lakes, whereas larger cells are more typical of hypolimnetic waters where phosphorus and nitrogen are not limiting. Indeed, temperature per se cannot be invoked as an important factor explaining the different bacterial size in the two zones. Without excluding the top-down control mechanism of bacterial size, our data suggest that the average lower size of bacterial cells in the epilimnion of oligotrophic lakes is controlled by outcompetition over the larger cells at limiting nutrients.

  10. Allelopathic bacteria and their impact on higher plants.

    Barazani, O; Friedman, J

    2001-01-01

    The impact of allelopathic, nonpathogenic bacteria on plant growth in natural and agricultural ecosystems is discussed. In some natural ecosystems, evidence supports the view that in the vicinity of some allelopathically active perennials (e.g., Adenostoma fasciculatum, California), in addition to allelochemicals leached from the shrub's canopy, accumulation of phytotoxic bacteria or other allelopathic microorganisms amplify retardation of annuals. In agricultural ecosystems allelopathic bacteria may evolve in areas where a single crop is grown successively, and the resulting yield decline cannot be restored by application of minerals. Transfer of soils from areas where crop suppression had been recorded into an unaffected area induced crop retardation without readily apparent symptoms of plant disease. Susceptibility of higher plants to deleterious rhizobacteria is often manifested in sandy or so-called skeletal soils. Evaluation of phytotoxic activity under controlled conditions, as well as ways to apply allelopathic bacteria in the field, is approached. The allelopathic effect may occur directly through the release of allelochemicals by a bacterium that affects susceptible plant(s) or indirectly through the suppression of an essential symbiont. The process is affected by nutritional and other environmental conditions, some may control bacterial density and the rate of production of allelochemicals. Allelopathic nonpathogenic bacteria include a wide range of genera and secrete a diverse group of plant growth-mediating allelochemicals. Although a limited number of plant growth-promoting bacterial allelochemicals have been identified, a considerable number of highly diversified growth-inhibiting allelochemicals have been isolated and characterized. Some species may produce more than one allelochemical; for example, three different phyotoxins, geldanamycin, nigericin, and hydanthocidin, were isolated from Streptomyces hygroscopicus. Efforts to introduce naturally

  11. Bacteria and vampirism in cinema.

    Castel, O; Bourry, A; Thévenot, S; Burucoa, C

    2013-09-01

    A vampire is a non-dead and non-alive chimerical creature, which, according to various folklores and popular superstitions, feeds on blood of the living to draw vital force. Vampires do not reproduce by copulation, but by bite. Vampirism is thus similar to a contagious disease contracted by intravascular inoculation with a suspected microbial origin. In several vampire films, two real bacteria were staged, better integrated than others in popular imagination: Yersinia pestis and Treponema pallidum. Bacillus vampiris was created for science-fiction. These films are attempts to better define humans through one of their greatest fears: infectious disease. PMID:23916557

  12. Turning Bacteria Suspensions into Superfluids

    López, Héctor Matías; Gachelin, Jérémie; Douarche, Carine; Auradou, Harold; Clément, Eric

    2015-07-01

    The rheological response under simple shear of an active suspension of Escherichia coli is determined in a large range of shear rates and concentrations. The effective viscosity and the time scales characterizing the bacterial organization under shear are obtained. In the dilute regime, we bring evidence for a low-shear Newtonian plateau characterized by a shear viscosity decreasing with concentration. In the semidilute regime, for particularly active bacteria, the suspension displays a "superfluidlike" transition where the viscous resistance to shear vanishes, thus showing that, macroscopically, the activity of pusher swimmers organized by shear is able to fully overcome the dissipative effects due to viscous loss.

  13. Adoptive chemoimmunotherapy using ex vivo activated memory T-cells and cyclophosphamide: tumor lysis syndrome of a metastatic soft tissue sarcoma.

    Gold, J E; Malamud, S C; LaRosa, F; Osband, M E

    1993-09-01

    Adoptively transferred immune cells in combination with chemotherapeutic agents form the basis for adoptive chemoimmunotherapy (ACIT) of neoplastic disease. Autolymphocytes (ALT-cells) are ex vivo activated peripheral blood lymphocytes (PBL) from tumor-bearing hosts (TBH) that consist primarily of tumor-specific CD45RO+ (memory) T-cells. These ALT-cells combined with cimetidine (CIM) as autolymphocyte therapy (ALT), have previously been demonstrated to be a safe and active form of outpatient adoptive immunotherapy (AIT) in human TBH with metastatic renal cell cancer (RCC). We have previously described an effective ACIT protocol using ALT and cyclophosphamide (CY) for patients with relapsed and refractory non-RCC solid tumors. We now report a case of a patient with a metastatic gastric leiomyosarcoma to the liver, who developed a clinical picture consistent with a tumor-lysis syndrome (TLS), following salvage therapy for his tumor with ACIT using ALT and CY. TLS is a well-known complication resulting from the treatment of rapidly proliferating hematopoietic tumors such as Burkitt's lymphoma and acute lymphocytic leukemia. TLS has also been rarely described in chronic lymphocytic leukemia, as well as certain solid tumors such as breast cancer, small cell lung cancer, and medulloblastoma. However, there have been no previous reports of TLS occurring either secondary to immunotherapy or in sarcomas. The nature of these unusual findings is discussed. PMID:8342564

  14. Efficacy of continuous venovenous hemofiltration with chemotherapy in patients with Burkitt lymphoma and leukemia at high risk of tumor lysis syndrome.

    Choi, Kyung A; Lee, Jung Eun; Kim, Yoon-Goo; Kim, Dae Joong; Kim, Kihyun; Ko, Young Hyeh; Oh, Ha Young; Kim, Won Seog; Huh, Wooseong

    2009-07-01

    Tumor lysis syndrome (TLS) is a potentially fatal metabolic complication of chemotherapy for Burkitt lymphoma. It has not been established whether chemotherapy should be delayed in patients with spontaneous TLS, and several studies have shown poor prognoses in this group. This retrospective study evaluated the efficacy and safety of continuous venovenous hemofiltration (CVVH) with prephase chemotherapy using the modified LMB-89 regimen in patients with Burkitt lymphoma and leukemia (BL/L) at a high risk of developing TLS from February 1998 to February 2007. The chemotherapy regimen was followed by the modified LMB-89 protocol. CVVH was applied to all patients before prephase chemotherapy or within 2 h of chemotherapy. The median follow-up was 19.7 months (range 1-97.8). Eight patients had Burkitt lymphoma and three had Burkitt leukemia; their median age was 48 years. The international prognostic indices were >3 for all patients. Seven patients had spontaneous TLS and four patients were at a high risk of TLS. CVVH was continued for 109 h (range 70.5-157.5). No patient had fatal metabolic complications related to TLS. Renal function had recovered fully before induction chemotherapy in all but one patient. The 1-year event-free survival and overall survival rates were both 82%. In conclusion, chemotherapy combined with CVVH might be effective and safe in patients with advanced Burkitt lymphoma and leukemia at a high risk of developing TLS. PMID:19030857

  15. Recommendations for the evaluation of risk and prophylaxis of tumour lysis syndrome (TLS) in adults and children with malignant diseases: an expert TLS panel consensus.

    Cairo, Mitchell S; Coiffier, Bertrand; Reiter, Alfred; Younes, Anas

    2010-05-01

    Tumour lysis syndrome (TLS) is a life-threatening oncological emergency characterized by metabolic abnormalities including hyperuricaemia, hyperphosphataemia, hyperkalaemia and hypocalcaemia. These metabolic complications predispose the cancer patient to clinical toxicities including renal insufficiency, cardiac arrhythmias, seizures, neurological complications and potentially sudden death. With the increased availability of newer therapeutic targeted agents, such as rasburicase (recombinant urate oxidase), there are no published guidelines on the risk classification of TLS for individual patients at risk of developing this syndrome. We convened an international TLS expert consensus panel to develop guidelines for a medical decision tree to assign low, intermediate and high risk to patients with cancer at risk for TLS. Risk factors included biological evidence of laboratory TLS (LTLS), proliferation, bulk and stage of malignant tumour and renal impairment and/or involvement at the time of TLS diagnosis. An international TLS consensus expert panel of paediatric and adult oncologists, experts in TLS pathophysiology and experts in TLS prophylaxis and management, developed a final model of low, intermediate and high risk TLS classification and associated TLS prophylaxis recommendations. PMID:20331465

  16. The challenges of treating paraganglioma patients with {sup 177}Lu-DOTATATE PRRT: Catecholamine crises, tumor lysis syndrome and the need for modification of treatment protocols

    Makis, William; Mccann, Karey; Mcewan, Alexander J. B. [Dept. of Diagnostic Imaging, Cross Cancer Institute, Alberta (China)

    2015-09-15

    A high percentage of paragangliomas express somatostatin receptors that can be utilized for targeted radioisotope therapy. The aim of this study was to describe and discuss the challenges of treating these tumors with {sup 177}Lu-[DOTA0,Tyr3]octreotate (DOTATATE) radioisotope therapy using established protocols. Three paraganglioma patients were treated with 4–5 cycles of {sup 177}Lu-DOTATATE and were evaluated for side effects and response to therapy. Two of the three patients developed severe adverse reactions following their first {sup 177}Lu-DOTATATE treatment. One patient developed a catecholamine crisis and tumor lysis syndrome within hours of treatment, requiring intensive care unit (ICU) support, and another developed a catecholamine crisis 3 days after treatment, requiring hospitalization. The treatment protocols at our institution were subsequently modified by increasing the radioisotope infusion time from 15 to 30 min, as recommended in the literature, to 2–4 h and by reducing the administered dose of {sup 177}Lu-DOTATATE. Subsequent {sup 177}Lu-DOTATATE treatments utilizing the modified protocols were well tolerated, and response to therapy was achieved in all three patients, resulting in significantly improved quality of life. {sup 177}Lu-DOTATATE is an exciting new therapeutic option in the management of paragangliomas; however, current treatment protocols described in the literature may need to be modified by lengthening the infusion time and/or lowering the initial treatment dose to prevent or reduce the severity of adverse reactions.

  17. The challenges of treating paraganglioma patients with 177Lu-DOTATATE PRRT: Catecholamine crises, tumor lysis syndrome and the need for modification of treatment protocols

    A high percentage of paragangliomas express somatostatin receptors that can be utilized for targeted radioisotope therapy. The aim of this study was to describe and discuss the challenges of treating these tumors with 177Lu-[DOTA0,Tyr3]octreotate (DOTATATE) radioisotope therapy using established protocols. Three paraganglioma patients were treated with 4–5 cycles of 177Lu-DOTATATE and were evaluated for side effects and response to therapy. Two of the three patients developed severe adverse reactions following their first 177Lu-DOTATATE treatment. One patient developed a catecholamine crisis and tumor lysis syndrome within hours of treatment, requiring intensive care unit (ICU) support, and another developed a catecholamine crisis 3 days after treatment, requiring hospitalization. The treatment protocols at our institution were subsequently modified by increasing the radioisotope infusion time from 15 to 30 min, as recommended in the literature, to 2–4 h and by reducing the administered dose of 177Lu-DOTATATE. Subsequent 177Lu-DOTATATE treatments utilizing the modified protocols were well tolerated, and response to therapy was achieved in all three patients, resulting in significantly improved quality of life. 177Lu-DOTATATE is an exciting new therapeutic option in the management of paragangliomas; however, current treatment protocols described in the literature may need to be modified by lengthening the infusion time and/or lowering the initial treatment dose to prevent or reduce the severity of adverse reactions

  18. Bleomycin-induced pulmonary fibrosis after tumor lysis syndrome in a case of advanced yolk sac tumor treated with bleomycin, etoposide and cisplatin (BEP) chemotherapy.

    Doi, Mihoko; Okamoto, Yohei; Yamauchi, Masami; Naitou, Hiroyuki; Shinozaki, Katsunori

    2012-10-01

    Ovarian yolk sac tumor (YST) is a highly aggressive malignancy arising in young women. Chemotherapy has dramatically improved the prognosis, and bleomycin, etoposide, and cisplatin (BEP) combination chemotherapy appears to be the most effective combination regimen. A 23-year-old woman was admitted to our hospital with worsening abdominal distention and a lower abdominal mass. She was diagnosed with a stage IIIc pure YST of the right ovary, and right salpingo-oophorectomy was performed; there were numerous disseminated peritoneal tumors within the abdominal cavity. A few days postoperatively, massive ascites developed, and right hydronephrosis occurred. Chemotherapy with BEP was started, and after 24 h of administration, oliguria and tumor lysis syndrome (TLS) developed. Continuous hemodiafiltration was started, and hemodialysis was initiated following full-dose standard cisplatin and etoposide on days 2-5 of the 1st cycle. After the electrolyte abnormalities and the elevation of creatinine became normal, the patient received an additional three cycles of BEP and achieved complete remission. However, she also suffered from severe non-hematological toxicities, including grade 3 left ventricular dysfunction and grade 4 pulmonary fibrosis. In the case of rapidly progressing and high-volume YST treated with BEP chemotherapy, special attention should be paid to bleomycin-induced pulmonary toxicity following TLS. Further study is required to optimize drug exposure to ensure efficacy and reduce the risk of side effects in this population. PMID:22127348

  19. Characterization of the involvement of two compensatory autolysins in mother cell lysis during sporulation of Bacillus subtilis 168.

    Smith, T J; Foster, S. J.

    1995-01-01

    The 30-kDa sporulation-specific peptidoglycan hydrolase CwlC of Bacillus subtilis 168 was purified and characterized. It is an N-acetylmuramoyl-L-alanine amidase (amidase) that is associated with the mother cell wall of sporulating cells, and although it is secreted, it undergoes no N-terminal processing except removal of the initial methionine. It was found that mother cells of a strain insertionally inactivated in cwlC and lytC (the major vegetative amidase gene) did not lyse at the end of ...

  20. Multiple-site mutations of phage Bp7 endolysin improves its activities against target bacteria

    Can; Zhang; Yuanchao; Wang; Huzhi; Sun; Huiying; Ren

    2015-01-01

    The widespread use of antibiotics has caused serious drug resistance. Bacteria that were once easily treatable are now extremely difficult to treat. Endolysin can be used as an alternative to antibiotics for the treatment of drug-resistant bacteria. To analyze the antibacterial activity of the endolysin of phage Bp7(Bp7e), a 489-bp DNA fragment of endolysin Bp7e was PCR-amplified from a phage Bp7 genome and cloned, and then a p ET28a-Bp7e prokaryotic expression vector was constructed. Two amino acids were mutated(L99A, M102E) to construct p ET28a-Bp7Δe, with p ET28a-Bp7e as a template. Phylogenetic analysis suggested that BP7e belongs to a T4-like phage endolysin group. Bp7e and its mutant Bp7Δe were expressed in Escherichia coli BL21(DE3) as soluble proteins. They were purified by affinity chromatography, and then their antibacterial activities were analyzed. The results demonstrated that the recombinant proteins Bp7e and Bp7Δe showed obvious antibacterial activity against Micrococcus lysodeikticus but no activity against Staphylococcus aureus. In the presence of malic acid, Bp7e and Bp7Δe exhibited an effect on most E. coli strains which could be lysed by phage Bp7, but no effect on Salmonella paratyphi or Pseudomonas aeruginosa. Moreover, Bp7Δe with double-site mutations showed stronger antibacterial activity and a broader lysis range than Bp7e.

  1. DMTB: the magnetotactic bacteria database

    Pan, Y.; Lin, W.

    2012-12-01

    Magnetotactic bacteria (MTB) are of interest in biogeomagnetism, rock magnetism, microbiology, biomineralization, and advanced magnetic materials because of their ability to synthesize highly ordered intracellular nano-sized magnetic minerals, magnetite or greigite. Great strides for MTB studies have been made in the past few decades. More than 600 articles concerning MTB have been published. These rapidly growing data are stimulating cross disciplinary studies in such field as biogeomagnetism. We have compiled the first online database for MTB, i.e., Database of Magnestotactic Bacteria (DMTB, http://database.biomnsl.com). It contains useful information of 16S rRNA gene sequences, oligonucleotides, and magnetic properties of MTB, and corresponding ecological metadata of sampling sites. The 16S rRNA gene sequences are collected from the GenBank database, while all other data are collected from the scientific literature. Rock magnetic properties for both uncultivated and cultivated MTB species are also included. In the DMTB database, data are accessible through four main interfaces: Site Sort, Phylo Sort, Oligonucleotides, and Magnetic Properties. References in each entry serve as links to specific pages within public databases. The online comprehensive DMTB will provide a very useful data resource for researchers from various disciplines, e.g., microbiology, rock magnetism and paleomagnetism, biogeomagnetism, magnetic material sciences and others.

  2. The solubilisation of boar sperm membranes by different detergents - a microscopic, MALDI-TOF MS, 31P NMR and PAGE study on membrane lysis, extraction efficiency, lipid and protein composition

    Müller Karin; Braun Beate; Wibbelt Gudrun; Süß Rosmarie; Fuchs Beate; Jakop Ulrike; Schiller Jürgen

    2009-01-01

    Abstract Background Detergents are often used to isolate proteins, lipids as well as "detergent-resistant membrane domains" (DRMs) from cells. Different detergents affect different membrane structures according to their physico-chemical properties. However, the effects of different detergents on membrane lysis of boar spermatozoa and the lipid composition of DRMs prepared from the affected sperm membranes have not been investigated so far. Results Spermatozoa were treated with the selected de...

  3. BIOLOGICAL CONTROL OF DAMPING-OFF FUNGI OF AGOHO (CASUARINA EQUISETIFOLIA L. USING ANTAGONISTIC BACTERIA

    F.A. DELA PEÑA

    1994-01-01

    essential requirement of microorganisms can serve as potentially possible basis for competition. Another was antibiosis which is an inhibitory effect exerted by an organism upon another organism through the production of antibiotic compounds. Moreover, several strains of bacteria are effective in lysing cell walls of pathogenic fungi under laboratory conditions. Lysis is often attributed to production of cell wall degrading enzymes like chitinase and gluconase that may hydrolyze major constituents of fungal cell walls.

  4. Ozonation followed by ultraviolet irradiation provides effective bacteria inactivation in a freshwater recirculating system

    Recirculating aquaculture systems may require an internal disinfection process to control population growth of pathogens and heterotrophic bacteria. Ozonation and ultraviolet (UV) irradiation are two technologies that have been used to treat relatively large aquaculture flows, including flows withi...

  5. Produção de protoplastos e lise da parede celular de leveduras utilizando β-1,3 glucanase Protoplasts production and yeast cell wall lysis using β-1,3 glucanase

    Luciana Francisco Fleuri

    2010-06-01

    Full Text Available O presente trabalho visou a aplicação da β-1,3 glucanase lítica, obtida do microrganismo Cellulosimicrobium cellulans 191, na produção de protoplastos e na lise da parede celular de leveduras. A preparação bruta da enzima foi capaz de lisar as leveduras Kluyveromyces lodderi, Saccharomyces cerevisiae (Fleischmann e Itaiquara, S. cerevisiae KL-88, S. diastaticus NCYC 713, S. cerevisiae NCYC 1001, Candida glabrata NCYC 388, Kluyveromyces marxianus NCYC 587 e Hansenula mrakii NCYC 500. A β-1,3 glucanase purificada foi capaz de lisar as leveduras Saccharomyces cerevisiae KL-88, Saccharomyces capensis, Debaromyces vanriji, Pachysolen tannophillus, Kluyveromyces drosophilarum, Candida glabrata, Hansenula mrakii e Pichia membranaefaciens e formar protoplastos de Saccharomyces cerevisiae KL-88.The aim of this work was the application of lytic β-1,3 glucanase obtained from Cellulosimicrobium cellulans strain 191 in the production of protoplasts and lysis of yeast cell walls. The crude extract demonstrated lysis activity against the yeasts Kluyveromyces lodderi, Saccharomyces cerevisiae (Fleischmann and Itaiquara, S. cerevisiae KL-88, S. diastaticus NCYC 713, S. cerevisiae NCYC 1001, Candida glabrata NCYC 388, Kluyveromyces marxianus NCYC 587, and Hansenula mrakii NCYC 500. The purified β-1,3 glucanase demonstrated lysis activity against the yeasts Saccharomyces cerevisiae KL-88, Saccharomyces capensis, Debaromyces vanriji, Pachysolen tannophillus, Kluyveromyces drosophilarum, Candida glabrata, Hansenula mrakii, and Pichia membranaefaciens, and it was able to produce Saccharomyces cerevisiae KL-88 protoplasts.

  6. Effect of Different Filling Materials in Anammox Bacteria Enrichment

    Dilek ÖZGÜN

    2012-12-01

    Full Text Available Purpose: Anaerobic ammonium oxidation (Anammox is a process that ammonium as electron donor is oxidized to nitrogen gas using nitrite as electron acceptor. Compared to conventional nitrification-denitrification processes, this process is used less oxygen and no organic material (methanol, glucose. However, the slow growth rate of Anammox bacteria (11-30 days is disadvantages. Therefore, batch reactors have been carried out in these bacteria enrichment. In this study continuously operated upflow anaerobic sludge reactor (UASB using different filling materials disposing of sensitive and slow-growing Anammox bacteria out of the system is purposed. Design and Methods: System is operated up-flow column reactor at 2 days hydraulic retention time (HRT in 45 days. In this study, ceramic stones and Linpor filling material are used. Using synthetic wastewater containing ammonium and nitrite, Ar/CO2 anaerobic conditions (95/5% supplied with gas. System is operated at a temperature 253 C in UASB. Temperature, pH, ammonia-nitrogen and nitrite nitrogen are measured. Results: Both filling material reactors are operated in 45 days. Ceramic stones filling reactor is observed quickly reaches 90% were used reactor ammonium removal. The ammonium nitrogen removal was slower in Linpor filling materials reactor. Nitrite removal is reached up to 90% in both the reactor. When compared to the stoichiometric equation in Linpor was composed of large amounts of nitrate. At the end of 25 days the results were similar to ceramic stone filling reactor with Linpor filling material reactors. Conclusions and Original Value: Anammox process as from nitrogen removal processes was discovered in 1995. Anammox bacteria that make up this process due to very low growth rates of microbial bacteria in the system must be kept in the system. Most of the studies in the literature, these bacteria enrichment stage is started instead of a continuous batch reactor system. In this study

  7. Nitrogen removal by autotrophic ammonium oxidizing bacteria enrichment under anaerobic conditions

    Pongsak (Lek Noophan

    2008-07-01

    Full Text Available Sludge from an anoxic tank at the centralized wastewater treatment plant, Nong Khaem, Bangkok, Thailand, was inoculatedin an anaerobic sequencing batch reactor (ASBR. The optimal compositions and operating conditions of the stock of autotrophic ammonium oxidizing bacteria medium were determined. The process of oxidizing ammonium with bacteria under anaerobic conditions is often referred to as the Anammox process (NO2- to N2 gas, using NH4+ as the electron donor and NO2- as the electron acceptor. The startup period for the anammox culture took more than three months. With ammoniumand nitrite concentration ratios of 1:1.38 and 1:1.6, the nitrogen conversion rate zero order. Fluorescent in situ hybridization(FISH was used to identify specific autotrophic ammonium oxidizing bacteria (Nitrosomonas spp., Candidatus Brocadia anammoxidans, and Candidatus Kuenenia stuttgartiensis. Results from this work demonstrated a shift in the species of ammonium oxidizing bacteria from Nitrosomonas spp. to Candidati Brocadia anammoxidans and Kuenenia stuttgartiensis, with increased ammonium concentrations from 3 mM to 15 mM. Under NH4+:NO2- ratios of 1:1.38 and 1:1.6 the ammoniumoxidizing bacteria were able to remove both ammonium and nitrite simultaneously. The specific nitrogen removal rate of theanammox bacteria (Candidati Brocadia anammoxidans and Kuenenia stuttgartiensis was significantly higher than that of anaerobic ammonium oxidizing bacteria (Nitrosomonas spp.. Anaerobic ammonium oxidizing bacteria (Candidati Brocadia anammoxidans and Kuenenia stuttgartiensis are strict anaerobes.

  8. Sulfur metabolism in phototrophic sulfur bacteria

    Frigaard, Niels-Ulrik; Dahl, Christiane

    2008-01-01

    Phototrophic sulfur bacteria are characterized by oxidizing various inorganic sulfur compounds for use as electron donors in carbon dioxide fixation during anoxygenic photosynthetic growth. These bacteria are divided into the purple sulfur bacteria (PSB) and the green sulfur bacteria (GSB). They...... utilize various combinations of sulfide, elemental sulfur, and thiosulfate and sometimes also ferrous iron and hydrogen as electron donors. This review focuses on the dissimilatory and assimilatory metabolism of inorganic sulfur compounds in these bacteria and also briefly discusses these metabolisms in...... other types of anoxygenic phototrophic bacteria. The biochemistry and genetics of sulfur compound oxidation in PSB and GSB are described in detail. A variety of enzymes catalyzing sulfur oxidation reactions have been isolated from GSB and PSB (especially Allochromatium vinosum, a representative of the...

  9. Transformation of gram positive bacteria by sonoporation

    Yang, Yunfeng; Li, Yongchao

    2014-03-11

    The present invention provides a sonoporation-based method that can be universally applied for delivery of compounds into Gram positive bacteria. Gram positive bacteria which can be transformed by sonoporation include, for example, Bacillus, Streptococcus, Acetobacterium, and Clostridium. Compounds which can be delivered into Gram positive bacteria via sonoporation include nucleic acids (DNA or RNA), proteins, lipids, carbohydrates, viruses, small organic and inorganic molecules, and nano-particles.

  10. Mortality of fecal bacteria in seawater.

    Garcia-Lara, J.; Menon, P.; Servais, P; Billen, G.

    1991-01-01

    We propose a method for determining the mortality rate for allochthonous bacteria released in aquatic environments without interference due to the loss of culturability in specific culture media. This method consists of following the disappearance of radioactivity from the trichloroacetic acid-insoluble fraction in water samples to which [3H]thymidine-prelabeled allochthonous bacteria have been added. In coastal seawater, we found that the actual rate of disappearance of fecal bacteria was 1 ...

  11. Utilization of xylooligosaccharides by selected ruminal bacteria.

    Cotta, M A

    1993-01-01

    The ability of ruminal bacteria to utilize xylooligosaccharides was examined. Xylooligosaccharides were prepared by partially hydrolyzing oat spelt xylan in phosphoric acid. This substrate solution was added (0.2%, wt/vol) to a complex medium containing yeast extract and Trypticase that was inoculated with individual species of ruminal bacteria, and growth and utilization were monitored over time. All of the xylanolytic bacteria examined were able to utilize this oligosaccharide mixture as a ...

  12. QUANTATITIVE PCR ASSAY FOR MARINE BACTERIA

    Brunk, Clifford F.

    2003-01-01

    Monitoring the bacterial flora in coastal marine waters by conventional techniques has been difficult as most of the bacteria do not readily grow on culture plates and their morphologies are virtually identical in the microscope. Molecular techniques, particularly characterizing bacteria using polymerase chain reaction (PCR) amplification of their small subunit ribosomal RNA (SSU rRNA) genes, has dramatically improved the ability to identify bacteria from environmental samples. Identificatio...

  13. Pathogenic bacteria and timing of laying

    Moller, Anders P.; Soler, Juan J; Nielsen, J T; Galván, Ismael

    2015-01-01

    Pathogenic bacteria constitute a serious threat to viability of many organisms. Because growth of most bacteria is favored by humid and warm environmental conditions, earlier reproducers in seasonal environments should suffer less from the negative consequences of pathogenic bacteria. These relationships, and the effects on reproductive success, should be particularly prominent in predators because they are frequently exposed to pathogenic microorganisms from sick prey. Here, we presented and...

  14. Interactions between Bacteria and Fungi on Aquatic Detritus – Causes and Consequences

    Mille-Lindblom, Cecilia

    2005-01-01

    Bacteria and fungi dominate the decomposition of aquatic plants, a major process in the carbon and nutrient cycling in many aquatic systems. Although phylogenetically distant, bacteria and fungi often live in close proximity with each other. Since these microorganisms also have similar ecological functions, interactions have developed between them. This thesis explores the nature of such interactions, and the potential effects on key components of the decomposition process. The thesis include...

  15. Nitrogen removal by autotrophic ammonium oxidizing bacteria enrichment under anaerobic conditions

    Pongsak (Lek) Noophan; Chalermraj Wantawin; Siriporn Sripiboon; Sanya Sirivitayapakorn

    2008-01-01

    Sludge from an anoxic tank at the centralized wastewater treatment plant, Nong Khaem, Bangkok, Thailand, was inoculatedin an anaerobic sequencing batch reactor (ASBR). The optimal compositions and operating conditions of the stock of autotrophic ammonium oxidizing bacteria medium were determined. The process of oxidizing ammonium with bacteria under anaerobic conditions is often referred to as the Anammox process (NO2- to N2 gas, using NH4+ as the electron donor and NO2- as the electron accep...

  16. Bacteria are different: Observations, interpretations, speculations, and opinions about the mechanisms of adaptive evolution in prokaryotes

    Levin, Bruce R.; Bergstrom, Carl T.

    2000-01-01

    To some extent, the genetic theory of adaptive evolution in bacteria is a simple extension of that developed for sexually reproducing eukaryotes. In other, fundamental ways, the process of adaptive evolution in bacteria is quantitatively and qualitatively different from that of organisms for which recombination is an integral part of the reproduction process. In this speculative and opinionated discussion, we explore these differences. In particular, we consider (i...

  17. Quorum sensing in gram-negative bacteria

    Wu, H.; Song, Z.J.; Høiby, N.; Givskov, Michael Christian

    2004-01-01

    Bacteria can communicate with each other by means of signal molecules to coordinate the behavior of the entire community, and the mechanism is referred to as quorum sensing (QS). Signal systems enable bacteria to sense the size of their densities by monitoring the concentration of the signal...... molecules. Among Gram-negative bacteria N-acyl-L-homoserine lactone (acyl-HSL)-dependent quorum sensing systems are particularly widespread. These systems are used to coordinate expression of phenotypes that are fundamental to the interaction of bacteria with each other and with their environment and...

  18. In vitro susceptibility testing of anaerobic bacteria.

    Washington, J A

    1979-01-01

    In vitro susceptibility testing of anaerobic bacteria should be limited to isolates from persistent or recurrent infections that have been treated adequately and appropriately with antimicrobial agents and, in reference centers, to collections of isolates in order to monitor alterations in susceptibility of species to various antimicrobial agents. An agar dilution reference method is being evaluated currently; however, practicality limits sporadic testing of single isolates to disk elution or broth dilution techniques. No single disk diffusion method has yet been found to be acceptable for testing anaerobic bacteria, and the results obtained with standardized procedures for aerobic and facultatively anaerobic bacteria are not applicable to anaerobic bacteria. PMID:288163

  19. Cell Size Regulation in Bacteria

    Amir, Ariel

    2014-05-01

    Various bacteria such as the canonical gram negative Escherichia coli or the well-studied gram positive Bacillus subtilis divide symmetrically after they approximately double their volume. Their size at division is not constant, but is typically distributed over a narrow range. Here, we propose an analytically tractable model for cell size control, and calculate the cell size and interdivision time distributions, as well as the correlations between these variables. We suggest ways of extracting the model parameters from experimental data, and show that existing data for E. coli supports partial size control, and a particular explanation: a cell attempts to add a constant volume from the time of initiation of DNA replication to the next initiation event. This hypothesis accounts for the experimentally observed correlations between mother and daughter cells as well as the exponential dependence of size on growth rate.

  20. Single Bacteria as Turing Machines

    Bos, Julia; Zang, Qiucen; Vyawahare, Saurabh; Austin, Robert

    2014-03-01

    In Allan Turing's famous 1950 paper on Computing Machinery and Intelligence, he started with the provocative statement: ``I propose to consider the question, `Can machines think?' This should begin with definitions of the meaning of the terms `machine' and `think'.'' In our own work on exploring the way that organisms respond to stress and evolve, it seems at times as if they come to remarkably fast solutions to problems, indicating some sort of very clever computational machinery. I'll discuss how it would appear that bacteria can indeed create a form of a Turing Machine, the first example of a computer, and how they might use this algorithm to do rapid evolution to solve a genomics problem.