Sample records for rod-shaped non-spore-forming bacteria

  1. The structural bases of long-term anabiosis in non-spore-forming bacteria (United States)

    Suzina, Natalia E.; Mulyukin, Andrey L.; Dmitriev, Vladimir V.; Nikolaev, Yury A.; Shorokhova, Anna P.; Bobkova, Yulia S.; Barinova, Ekaterina S.; Plakunov, Vladimir K.; El-Registan, Galina I.; Duda, Vitalii I.


    Peculiarities of the structural organization in non-spore-forming bacteria associated with long-term anabiosis were revealed both in laboratory cultures and in natural populations isolated from 1 3-Myr-old Eastern Siberian permafrost and tundra soil. Different advanced methods were used, including (a) high-resolution electron microscopy; (b) simulation of in situ conditions in the laboratory by varying the composition of growth medium and cultivation conditions; (c) low-temperature fractionation to isolate and concentrate microbial cells from natural soils; (d) comparative morphological analysis of microbial cells in model cultures and natural soils (in situ). Under laboratory conditions, the intense formation of resting cells by representatives of various taxa of eubacteria and halophilic archaea occurred in 2 9-month-old cultures grown in carbon-, nitrogen-, or phosphorus-limited media, in starved cell suspensions in the presence of sodium silicate, or on soil agar. Among resting cells, we revealed cystlike forms having a complicated structure and common features. These included a thick capsule; a thickened and multiprofile cell wall; the presence of large intramembrane particles on PF- and EF-fracture surfaces; fine-grained or lumpy cytoplasm; and a condensed nucleoid. The general morphological properties, ultrastructural organization, physiological features of cystlike cells, and their ability to germinate under the appropriate conditions suggest the existence of constitutive dormancy in non-spore-forming bacteria. It was found that the majority of microorganisms in permafrost and tundra soil are cystlike cells, very similar to those in laboratory cultures. Anabiotic (resting) cystlike cells are responsible for the survival of non-spore-formers in extreme Earth habitats and may be regarded as possible analogs of extraterrestrial forms of microbial life.

  2. Mechanism for longitudinal growth of rod-shaped bacteria (United States)

    Taneja, Swadhin; Levitan, Ben; Rutenberg, Andrew


    The peptidoglycan (PG) cell wall along with MreB proteins are major determinants of shape in rod-shaped bacteria. However the mechanism guiding the growth of this elastic network of cross-linked PG (sacculus) that maintains the integrity and shape of the rod-shaped cell remains elusive. We propose that the known anisotropic elasticity and anisotropic loading, due to the shape and turgor pressure, of the sacculus is sufficient to direct small gaps in the sacculus to elongate around the cell, and that subsequent repair leads to longitudinal growth without radial growth. We computationally show in our anisotropically stressed anisotropic elasticity model small gaps can extend stably in the circumferential direction for the known elasticity of the sacculus. We suggest that MreB patches that normally propagate circumferentially, are associated with these gaps and are steered with this common mechanism. This basic picture is unchanged in Gram positive and Gram negative bacteria. We also show that small changes of elastic properties can in fact lead to bi-stable propagation of gaps, both longitudinal and circumferential, that can explain the bi-stability in patch movement observed in ΔmblΔmreb mutants.

  3. Spatio-Temporal Patterns in Colonies of Rod-Shaped Bacteria (United States)

    Kitsunezaki, S.

    In incubation experiments of bacterial colonies of Proteus Mirabilis, macroscopic spatio-temporal patterns, such as turbulent and unidirectional spiral patterns, appear in colonies. Considering only kinetic propeties of rod-shaped bacteria, we propose a phenomenological model for the directional and positional distributions. As the average density increases, homogeneous states bifurcate sub-critically into nonuniform states exhibiting localized collective motion, and spiral patterns appear for sufficiently large density. These patterns result from interactions between the local bacteria densities and the order parameter representing collective motion. Our model can be described by reduced equations using a perturbative method for large density. The unidirectionality of sprial rotation is also discussed.

  4. Long helical filaments are not seen encircling cells in electron cryotomograms of rod-shaped bacteria

    International Nuclear Information System (INIS)

    Swulius, Matthew T.; Chen, Songye; Jane Ding, H.; Li, Zhuo; Briegel, Ariane; Pilhofer, Martin; Tocheva, Elitza I.; Lybarger, Suzanne R.; Johnson, Tanya L.; Sandkvist, Maria; Jensen, Grant J.


    Highlights: → No long helical filaments are seen near or along rod-shaped bacterial inner membranes by electron cryo-tomography. → Electron cryo-tomography has the resolution to detect single filaments in vivo. -- Abstract: How rod-shaped bacteria form and maintain their shape is an important question in bacterial cell biology. Results from fluorescent light microscopy have led many to believe that the actin homolog MreB and a number of other proteins form long helical filaments along the inner membrane of the cell. Here we show using electron cryotomography of six different rod-shaped bacterial species, at macromolecular resolution, that no long (>80 nm) helical filaments exist near or along either surface of the inner membrane. We also use correlated cryo-fluorescent light microscopy (cryo-fLM) and electron cryo-tomography (ECT) to identify cytoplasmic bundles of MreB, showing that MreB filaments are detectable by ECT. In light of these results, the structure and function of MreB must be reconsidered: instead of acting as a large, rigid scaffold that localizes cell-wall synthetic machinery, moving MreB complexes may apply tension to growing peptidoglycan strands to ensure their orderly, linear insertion.

  5. Is Longitudinal Division in Rod-Shaped Bacteria a Matter of Swapping Axis?

    Directory of Open Access Journals (Sweden)

    Tanneke den Blaauwen


    Full Text Available The morphology of bacterial species shows a wealth of variation from star-shaped to spherical and rod- to spiral-shaped, to mention a few. Their mode of growth and division is also very diverse and flexible ranging from polar growth and lateral surface increase to midcell expansion and from perpendicular to longitudinal asymmetric division. Gammaproteobacterial rod-shaped species such as Escherchia coli divide perpendicularly and grow in length, whereas the genetically very similar rod-shaped symbiotic Thiosymbion divide longitudinally, and some species even divide asynchronously while growing in width. The ovococcal Streptococcus pneumoniae also lengthens and divides perpendicularly, yet it is genetically very different from E. coli. Are these differences as dramatic as is suggested by visual inspection, or can they all be achieved by subtle variation in the regulation of the same protein complexes that synthesize the cell envelope? Most bacteria rely on the cytoskeletal polymer FtsZ to organize cell division, but only a subset of species use the actin homolog MreB for length growth, although some of them are morphologically not that different. Poles are usually negative determinant for cell division. Curved cell poles can be inert or active with respect to peptidoglycan synthesis, can localize chemotaxis and other sensing proteins or other bacterial equipment, such as pili, depending on the species. But what is actually the definition of a pole? This review discusses the possible common denominators for growth and division of distinct and similar bacterial species.

  6. An automated and highly efficient method for counting and measuring fluorescent foci in rod-shaped bacteria

    DEFF Research Database (Denmark)

    Nielsen, Henrik Jørck; Hansen, Flemming G.


    P>Direct measurements of cells from photo micrographs are becoming increasingly used when investigating the position and/or distribution of chromosomal loci in bacteria. In general, these measurements have been done manually, and without clear definition of how they are made. Here we present...

  7. Morphogenesis of rod-shaped sacculi

    NARCIS (Netherlands)

    den Blaauwen, T.; de Pedro, M.A.; Nguyen-Distèche, M.; Ayala, J.A.


    For growth and division of rod-shaped bacteria, the cylindrical part of the sacculus has to be elongated and two new cell poles have to be synthesized. The elongation is performed by a protein complex, the elongase that inserts disaccharidepentapeptide units at a limited number of discrete sites

  8. Long-term cryopreservation of non-spore-forming fungi in Microbank™ beads for plant pathological investigations. (United States)

    Lakshman, Dilip K; Singh, Vimla; Camacho, Manuel E


    Long-term preservation of experimental fungi without genetic, morphological, and pathogenic changes is of paramount importance in mycological and plant pathological investigations. Several cryogenic and non-cryogenic methods are available for the preservation of fungi, but the methods can be cumbersome, hazardous, expensive, and often not suitable for long-term storage of non-spore-forming (sterile) fungi. A method of preservation of spore-forming fungi in commercially available porous beads (Micrbank™) under cryogenic condition was successfully tested for three non-spore-forming basidiomycetes genera: Rhizoctonia solani (teleomorph: Thanatephorus cucumeris) (n = 19), Ceratobasidium species (n = 1), and Waitea circinata (n = 3), and a non-spore forming ascomycetes, Sclerotinia sclerotiorum (n = 1). For comparison, spore-forming ascomycetous fungi, Alternaria alternata (n = 1), Bauveria basiana (n = 2), Botrytis cinerea (n = 1), Fusarium oxysporum f.sp. gladiolii (n = 1), Trichoderma spp. (n = 3), and Thielaviopsis basicola (n = 2) were also cryopreserved in Microbank beads. Viable fungal isolates of all test species were retrieved after five years of storage at -80 °C, which was longer than the viabilities of the corresponding isolates cryopreserved in agar plugs or colonized wheat seeds. Fungi revived from the Microbank beads maintained identical morphology and cultural characteristics of the parent isolates. Randomly selected Rhizoctonia isolates revived from the Microbank beads maintained respective pathological properties of the parent isolates; also, no mutation was detected in the internal transcribed spacer (ITS) ribosomal DNA when compared with respective cultures maintained at ambient temperature. This finding demonstrated the utility of cryopreservation in Microbank beads as a convenient alternative to conventional long-term preservation of a wide group of fungal cultures for plant pathological investigations

  9. Anaerobic bacteria (United States)

    Anaerobic bacteria are bacteria that do not live or grow when oxygen is present. In humans, these bacteria ... Brook I. Diseases caused by non-spore-forming anaerobic bacteria. In: Goldman L, Schafer AI, eds. Goldman-Cecil ...

  10. Treatment of rod shaped intermediate active waste

    International Nuclear Information System (INIS)

    Graf, A.; Blase, F.; Dirks, F.; Valencia, L.


    The Central Decontamination Operation Department (HDB) of the Research Center Karlsruhe operates facilities for the disposal of radioactive waste. In general, their objective is to reduce the volume of the radioactive waste and to obtain waste products suitable for repository storage. One of the central facilities of the HDB is the intermediate level waste (ILW) scrapping facility which processes intermediate level waste. Since the ILW scrapping facility was not large enough to handle radioactive waste coming from the dismantling and operating of nuclear facilities, HDB expanded and built a larger hot cell. It contains a hydraulically driven metal cutter with a guiding channel and a high pressure compactor. A major task in the hot cell of the ILW scrapping facility is disposing of fuel boxes. These are cut in pieces and scrapped, which is a unique technique in Germany for fuel box disposal. HDB's experiences in disposing of radioactive waste in the ILW scrapping facility will described in detail, with special emphasis on the handling of rod shaped components. (author)

  11. Biosynthesis and recovery of rod-shaped tellurium nanoparticles and their bactericidal activities

    Energy Technology Data Exchange (ETDEWEB)

    Zare, Bijan; Faramarzi, Mohammad Ali; Sepehrizadeh, Zargham [Department of Pharmaceutical Biotechnology and Biotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, P.O. Box 14155-6451 Tehran (Iran, Islamic Republic of); Shakibaie, Mojtaba [Department of Pharmacognosy and Biotechnology, School of Pharmacy, Pharmaceutics Research Center, Kerman University of Medical Sciences, P.O. Box 76175-493 Kerman (Iran, Islamic Republic of); Rezaie, Sassan [Department of Medical Biotechnology, School of Advanced Medical Technologies, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Shahverdi, Ahmad Reza, E-mail: [Department of Pharmaceutical Biotechnology and Biotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, P.O. Box 14155-6451 Tehran (Iran, Islamic Republic of)


    Highlights: ► Biosynthesis of rod shape tellurium nanoparticles with a hexagonal crystal structure. ► Extraction procedure for isolation of tellurium nanoparticles from Bacillus sp. BZ. ► Extracted tellurium nanoparticles have good bactericidal activity against some bacteria. -- Abstract: In this study, a tellurium-transforming Bacillus sp. BZ was isolated from the Caspian Sea in northern Iran. The isolate was identified by various tests and 16S rDNA analysis, and then used to prepare elemental tellurium nanoparticles. The isolate was subsequently used for the intracellular biosynthesis of elemental tellurium nanoparticles. The biogenic nanoparticles were released by liquid nitrogen and purified by an n-octyl alcohol water extraction system. The shape, size, and composition of the extracted nanoparticles were characterized. The transmission electron micrograph showed rod-shaped nanoparticles with dimensions of about 20 nm × 180 nm. The energy dispersive X-ray and X-ray diffraction spectra respectively demonstrated that the extracted nanoparticles consisted of only tellurium and have a hexagonal crystal structure. This is the first study to demonstrate a biological method for synthesizing rod-shaped elemental tellurium by a Bacillus sp., its extraction and its antibacterial activity against different clinical isolates.

  12. Biosynthesis and recovery of rod-shaped tellurium nanoparticles and their bactericidal activities

    International Nuclear Information System (INIS)

    Zare, Bijan; Faramarzi, Mohammad Ali; Sepehrizadeh, Zargham; Shakibaie, Mojtaba; Rezaie, Sassan; Shahverdi, Ahmad Reza


    Highlights: ► Biosynthesis of rod shape tellurium nanoparticles with a hexagonal crystal structure. ► Extraction procedure for isolation of tellurium nanoparticles from Bacillus sp. BZ. ► Extracted tellurium nanoparticles have good bactericidal activity against some bacteria. -- Abstract: In this study, a tellurium-transforming Bacillus sp. BZ was isolated from the Caspian Sea in northern Iran. The isolate was identified by various tests and 16S rDNA analysis, and then used to prepare elemental tellurium nanoparticles. The isolate was subsequently used for the intracellular biosynthesis of elemental tellurium nanoparticles. The biogenic nanoparticles were released by liquid nitrogen and purified by an n-octyl alcohol water extraction system. The shape, size, and composition of the extracted nanoparticles were characterized. The transmission electron micrograph showed rod-shaped nanoparticles with dimensions of about 20 nm × 180 nm. The energy dispersive X-ray and X-ray diffraction spectra respectively demonstrated that the extracted nanoparticles consisted of only tellurium and have a hexagonal crystal structure. This is the first study to demonstrate a biological method for synthesizing rod-shaped elemental tellurium by a Bacillus sp., its extraction and its antibacterial activity against different clinical isolates.

  13. Lactobacillus micheneri sp. nov., Lactobacillus timberlakei sp. nov. and Lactobacillus quenuiae sp. nov., lactic acid bacteria isolated from wild bees and flowers. (United States)

    McFrederick, Quinn S; Vuong, Hoang Q; Rothman, Jason A


    Gram-stain-positive, rod-shaped, non-spore forming bacteria have been isolated from flowers and the guts of adult wild bees in the families Megachilidae and Halictidae. Phylogenetic analysis of the 16S rRNA gene indicated that these bacteria belong to the genus Lactobacillus, and are most closely related to the honey-bee associated bacteria Lactobacillus kunkeei (97.0 % sequence similarity) and Lactobacillus apinorum (97.0 % sequence similarity). Phylogenetic analyses of 16S rRNA genes and six single-copy protein coding genes, in situ and in silico DNA-DNA hybridization, and fatty-acid profiling differentiates the newly isolated bacteria as three novel Lactobacillus species: Lactobacillus micheneri sp. nov. with the type strain Hlig3 T (=DSM 104126 T ,=NRRL B-65473 T ), Lactobacillus timberlakei with the type strain HV_12 T (=DSM 104128 T ,=NRRL B-65472 T ), and Lactobacillus quenuiae sp. nov. with the type strain HV_6 T (=DSM 104127 T ,=NRRL B-65474 T ).

  14. Reactor core with rod-shaped fuel cells

    International Nuclear Information System (INIS)

    Dworak, A.


    The proposal refers to the optimization of the power distribution in a reactor core which is provided with several successive rod-shaped fuel cells. A uniform power output - especially in radial direction - is aimed at. This is achieved by variation of the dwelling periods of the fuel cells, which have, for this purpose, a fuel mixture changing from layer to layer. The fuel cells with the shortest dwelling period are arranged near the coolant inlet side of the reactor core. The dwelling periods of the fuel cells are adapted to the given power distribution. As neighboring cells have equal dwelling periods, the exchange can be performed much easier then with the composition currently known. (UWI) [de

  15. Reactor core with rod-shaped fuel cells

    International Nuclear Information System (INIS)

    Dworak, A.


    Power distribution in a high-temperature gas-cooled reactor is optimized. Especially the axial as well as the radial power distribution is kept constant, the core consisting of several consecutive rod-shaped fuel cells. To this end, the dwell times of the fuel cells are fitted to the given power distribution. Fuel cells with equal dwell times, seen in flow direction, are arranged side by side, and those with the shortest dwell times are placed in areas with the greatest power release. These areas ly on the coolant inlet side. To keep the power distribution constant, fuel cells with neutron poison or absorber rods with absorbing rates decreasing in flow direction can also be inserted. (RW/PB) [de

  16. Preparation and characterization of the rod-shaped stibnite

    Energy Technology Data Exchange (ETDEWEB)

    Ouni, B., E-mail: [Unité de Physique des Dispositifs a Semi-conducteurs, Faculté des Sciences deTunis, Tunis El Manar University, 2092 Tunis (Tunisia); Zouini, M. [Laboratoire de Photovoltaïque, Centre de Recherches et des Technologies de l' Energie, Technopôle de Borj-Cédria, BP 95, Hammam-Lif 2050 (Tunisia); Lakhdar, M. Haj; Larbi, T. [Unité de Physique des Dispositifs a Semi-conducteurs, Faculté des Sciences deTunis, Tunis El Manar University, 2092 Tunis (Tunisia); Dimassi, W. [Laboratoire de Photovoltaïque, Centre de Recherches et des Technologies de l' Energie, Technopôle de Borj-Cédria, BP 95, Hammam-Lif 2050 (Tunisia); Amlouk, M. [Unité de Physique des Dispositifs a Semi-conducteurs, Faculté des Sciences deTunis, Tunis El Manar University, 2092 Tunis (Tunisia)


    Highlights: • A facile route to synthesize large-scale rod-like Sb{sub 2}S{sub 3} micro-wires was presented. • A deep analysis conjoint between band tails, band gap alteration and electrical model. • The band gap is 1.75 eV which may hold for solar energy conversion. - Abstract: Stibnite (Sb{sub 2}S{sub 3}) micro-wires have been grown on glass substrates by sulfuration of Sb thermal evaporated film in a vacuum sealed tube in presence of sulfur powder at 300 °C for 6 h. X-ray diffraction and Raman spectroscopy techniques indicate that the synthesized micro-wires have an orthorhombic structure. SEM micrographs show rod-shaped micro-wires with a typical length of several tens of micrometers and a diameter of the order of 0.5 μm. The absorption coefficient dependence on the photon energy in the UV–visible range revealed the existence of a direct transition with an energy band gap of about 1.7 eV. Moreover, the band tails and localized states which are related to the level of defects in the material will be presented. These parameters were determined from the exponential absorption profile. All these results have been evaluated and discussed in terms of alteration of band gap edge and electrical measurements.

  17. Recent Advances in the Study of Bipolar/Rod-Shaped Microglia and their Roles in Neurodegeneration

    Directory of Open Access Journals (Sweden)

    Ngan Pan Bennett Au


    Full Text Available Microglia are the resident immune cells of the central nervous system (CNS and they contribute to primary inflammatory responses following CNS injuries. The morphology of microglia is closely associated with their functional activities. Most previous research efforts have attempted to delineate the role of ramified and amoeboid microglia in the pathogenesis of neurodegenerative diseases. In addition to ramified and amoeboid microglia, bipolar/rod-shaped microglia were first described by Franz Nissl in 1899 and their presence in the brain was closely associated with the pathology of infectious diseases and sleeping disorders. However, studies relating to bipolar/rod-shaped microglia are very limited, largely due to the lack of appropriate in vitro and in vivo experimental models. Recent studies have reported the formation of bipolar/rod-shaped microglia trains in in vivo models of CNS injury, including diffuse brain injury, focal transient ischemia, optic nerve transection and laser-induced ocular hypertension (OHT. These bipolar/rod-shaped microglia formed end-to-end alignments in close proximity to the adjacent injured axons, but they showed no interactions with blood vessels or other types of glial cell. Recent studies have also reported on a highly reproducible in vitro culture model system to enrich bipolar/rod-shaped microglia that acts as a powerful tool with which to characterize this form of microglia. The molecular aspects of bipolar/rod-shaped microglia are of great interest in the field of CNS repair. This review article focuses on studies relating to the morphology and transformation of microglia into the bipolar/rod-shaped form, along with the differential gene expression and spatial distribution of bipolar/rod-shaped microglia in normal and pathological CNSs. The spatial arrangement of bipolar/rod-shaped microglia is crucial in the reorganization and remodeling of neuronal and synaptic circuitry following CNS injuries. Finally, we

  18. Characterization of the Lactobacillus isolated from different curd ...

    African Journals Online (AJOL)

    Lactic acid bacteria are commonly found in the fermented dairy products. Lactobacillus is a genus of lactic acid bacteria and described as heterogeneous group of regular, non-spore forming, gram-positive, rod shaped, non-motile bacteria and absence of catalase enzyme. The aim of this study was to isolate Lactobacillus ...

  19. Rod-Shaped Magnetite Nano/Microparticles Synthesis at Ambient Temperature

    Directory of Open Access Journals (Sweden)

    Balaprasad Ankamwar


    Full Text Available Here, we reported room temperature synthesis of Fe3O4 rod-shaped nano/microparticles by chemical reduction method from FeCl3 precursor and NaBH4 as the reducing agent in the presence of the pyrrole as a capping agent. The magnetic Fe3O4 particles were characterized by several methods, such as SEM, XRD, FTIR, and TGA. The average aspect ratio of Fe3O4 rod-shaped particles was ~2.8. These particles were redispersed in deionised water to form a colloidal solution and showed magnetic properties. This economical synthesis route is scalable, and Fe3O4 particles can be exploited for various applications such as MRI contrast enhancement, biodiseperations, Ni-Fe batteries, and as a catalyst.

  20. Modeling mechanical interactions in growing populations of rod-shaped bacteria (United States)

    Winkle, James J.; Igoshin, Oleg A.; Bennett, Matthew R.; Josić, Krešimir; Ott, William


    Advances in synthetic biology allow us to engineer bacterial collectives with pre-specified characteristics. However, the behavior of these collectives is difficult to understand, as cellular growth and division as well as extra-cellular fluid flow lead to complex, changing arrangements of cells within the population. To rationally engineer and control the behavior of cell collectives we need theoretical and computational tools to understand their emergent spatiotemporal dynamics. Here, we present an agent-based model that allows growing cells to detect and respond to mechanical interactions. Crucially, our model couples the dynamics of cell growth to the cell’s environment: Mechanical constraints can affect cellular growth rate and a cell may alter its behavior in response to these constraints. This coupling links the mechanical forces that influence cell growth and emergent behaviors in cell assemblies. We illustrate our approach by showing how mechanical interactions can impact the dynamics of bacterial collectives growing in microfluidic traps.

  1. Escherichia coli and other Enterobacteriaceae: Food poisoning and health effects (United States)

    The family Enterobactericeae consists of rod-shaped, Gram-negative, facultatively anaerobic, non-spore forming bacteria and also includes the food-borne pathogens, Cronobacter spp., Escherichia coli, Salmonella enterica, Shigella spp., and Yersinia spp. Illness caused by these pathogens is acquired...

  2. Demequina lutea sp. nov., isolated from a high Arctic permafrost soil

    DEFF Research Database (Denmark)

    Finster, Kai; Herbert, Rodney Andrew; Kjeldsen, Kasper Urup


    Two Gram-stain-positive, pigmented, non-motile, non-spore-forming, pleomorphic, rod-shaped bacteria (strains SV45T and SV47), isolated from a permafrost soil collected from the Adventdalen valley, Spitsbergen, northern Norway, have been characterized taxonomically using a polyphasic approach...

  3. Taxonomic study of aromatic-degrading bacteria from deep-terrestrial-subsurface sediments and description of Sphingomonas aromaticivorans sp. nov., Sphingomonas subterranea sp. nov., and Sphingomonas stygia sp. nov. (United States)

    Balkwill, D L; Drake, G R; Reeves, R H; Fredrickson, J K; White, D C; Ringelberg, D B; Chandler, D P; Romine, M F; Kennedy, D W; Spadoni, C M


    Phylogenetic analyses of 16S rRNA gene sequences by distance matrix and parsimony methods indicated that six strains of bacteria isolated from deep saturated Atlantic coastal plain sediments were closely related to the genus Sphingomonas. Five of the strains clustered with, but were distinct from, Sphingomonas capsulata, whereas the sixth strain was most closely related to Blastobacter natatorius. The five strains that clustered with S. capsulata, all of which could degrade aromatic compounds, were gram-negative, non-spore-forming, non-motile, rod-shaped organisms that produced small, yellow colonies on complex media. Their G + C contents ranged from 60.0 to 65.4 mol%, and the predominant isoprenoid quinone was ubiquinone Q-10. All of the strains were aerobic and catalase positive. Indole, urease, and arginine dihydrolase were not produced. Gelatin was not liquified, and glucose was not fermented. Sphingolipids were present in all strains; 2OH14:0 was the major hydroxy fatty acid, and 18:1 was a major constituent of cellular lipids. Acid was produced oxidatively from pentoses, hexoses, and disaccharides, but not from polyalcohols and indole. All of these characteristics indicate that the five aromatic-degrading strains should be placed in the genus Sphingomonas as currently defined. Phylogenetic analysis of 16S rRNA gene sequences, DNA-DNA reassociation values, BOX-PCR genomic fingerprinting, differences in cellular lipid composition, and differences in physiological traits all indicated that the five strains represent three previously undescribed Sphingomonas species. Therefore, we propose the following new species: Sphingomonas aromaticivorans (type strain, SMCC F199), Sphingomonas subterranea (type strain, SMCC B0478), and Sphingomonas stygia (type strain, SMCC B0712).

  4. Determination of the Persistence of Non-Spore-Forming ... (United States)

    Report This report presents the results of an investigation to evaluate the persistence (or natural attenuation) of Yersinia pestis (Y. pestis), Francisella tularensis (F. tularensis), and Burkholderia mallei (B. mallei) on glass and soil under multiple environmental conditions and time points.

  5. Novel rod-shaped viruses isolated from garlic, Allium sativum, possessing a unique genome organization. (United States)

    Sumi, S; Tsuneyoshi, T; Furutani, H


    Rod-shaped flexuous viruses were partially purified from garlic plants (Allium sativum) showing typical mosaic symptoms. The genome was shown to be composed of RNA with a poly(A) tail of an estimated size of 10 kb as shown by denaturing agarose gel electrophoresis. We constructed cDNA libraries and screened four independent clones, which were designated GV-A, GV-B, GV-C and GV-D, using Northern and Southern blot hybridization. Nucleotide sequence determination of the cDNAs, two of which correspond to nearly one-third of the virus genomic RNA, shows that all of these viruses possess an identical genomic structure and that also at least four proteins are encoded in the viral cDNA, their M(r)s being estimated to be 15K, 27K, 40K and 11K. The 15K open reading frame (ORF) encodes the core-like sequence of a zinc finger protein preceded by a cluster of basic amino acid residues. The 27K ORF probably encodes the viral coat protein (CP), based on both the existence of some conserved sequences observed in many other rod-shaped or flexuous virus CPs and an overall amino acid sequence similarity to potexvirus and carlavirus CPs. The 11K ORF shows significant amino acid sequence similarities to the corresponding 12K proteins of the potexviruses and carlaviruses. On the other hand, the 40K ORF product does not resemble any other plant virus gene products reported so far. The genomic organization in the 3' region of the garlic viruses resembles, but clearly differs from, that of carlaviruses. Phylogenetic analysis based upon the amino acid sequence of the viral capsid protein also indicates that the garlic viruses have a unique and distinct domain different from those of the potexvirus and carlavirus groups. The results suggest that the garlic viruses described here belong to an unclassified and new virus group closely related to the carlaviruses.

  6. Rod-shaped silica particles derivatized with elongated silver nanoparticles immobilized within mesopores

    Energy Technology Data Exchange (ETDEWEB)

    Mnasri, Najib [Institut Charles Gerhardt de Montpellier, CNRS UMR 5253, Université Montpellier, Place Eugène Bataillon, 34095 Montpellier Cedex 5 (France); Materials, Environment and Energy Laboratory (UR14ES26), Faculty of Science, University of Gafsa, 2112 Gafsa (Tunisia); Charnay, Clarence; Ménorval, Louis-Charles de [Institut Charles Gerhardt de Montpellier, CNRS UMR 5253, Université Montpellier, Place Eugène Bataillon, 34095 Montpellier Cedex 5 (France); Elaloui, Elimame [Materials, Environment and Energy Laboratory (UR14ES26), Faculty of Science, University of Gafsa, 2112 Gafsa (Tunisia); Zajac, Jerzy, E-mail: [Institut Charles Gerhardt de Montpellier, CNRS UMR 5253, Université Montpellier, Place Eugène Bataillon, 34095 Montpellier Cedex 5 (France)


    Silver-derivatized silica particles possessing a non-spherical morphology and surface plasmon resonance properties have been achieved. Nanometer-sized silica rods with uniformly sized mesopore channels were prepared first making use of alkyltrimethyl ammonium surfactants as porogens and the 1:0.10 tetraethyl orthosilicate (TEOS) : 3-aminopropyltriethoxysilane (APTES) mixture as a silicon source. Silica rods were subsequently functionalized by introducing elongated silver nanoparticles within the intra-particle mesopores thanks to the AgNO{sub 3} reduction procedure based on the action of hemiaminal groups previously located on the mesopore walls. The textural and structural features of the samples were inferred from the combined characterization studies including SEM and TEM microscopy, nitrogen adsorption-desorption at 77 K, powder XRD in the small- and wide-angle region, as well as UV–visible spectroscopy. {sup 129}Xe NMR spectroscopy appeared particularly useful to obtain a correct information about the porous structure of rod-shaped silica particles and the silver incorporation within their intra-particle mesopores. - Highlights: • Mesoporous monodisperse submicron-sized silica rods were achieved. • Silver nanoparticles were located lengthwise within the intra-particle mesopores. • Textural and plasmonic properties of particles studied by {sup 129}Xe NMR and UV–Vis.

  7. Repulsion between oppositely charged rod-shaped macromolecules: Role of overcharging and ionic confinement (United States)

    Antila, Hanne S.; Van Tassel, Paul R.; Sammalkorpi, Maria


    The interaction between two oppositely charged rod-shaped macro-ions in a micro-ion solution is investigated via Monte Carlo simulations of the primitive model. The focus is on the asymmetry in rod and/or ion charge, i.e., conditions where oppositely charged objects can repel one another. For equally and oppositely charged rods with asymmetric z:1 micro-ions, repulsion may be induced by overcharging one of the rods with the z valent ions. For asymmetrically charged rods in a symmetric z:z micro-ion solution, a repulsive interaction—at separation of the order of one ion diameter—can arise via an unbalanced osmotic pressure contribution from the ionic atmosphere in the inter-rod space, and an attractive interaction—at a smaller separation—may occur due to a "squeezing out" of the micro-ions from the space between the rods (with a consequent gain in entropy). The thermodynamics of each mechanism is investigated in terms of rod charge and size and micro-ion valence, size, and concentration. Our findings contribute to the understanding of the complex role of charge asymmetry on the interaction of, for example, oppositely charged polyelectrolytes, functionalized nanotubes, and rod-like biomolecules, e.g., viruses.

  8. Magnetic engineering of stable rod-shaped stem cell aggregates: circumventing the pitfall of self-bending. (United States)

    Du, V; Fayol, D; Reffay, M; Luciani, N; Bacri, J-C; Gay, C; Wilhelm, C


    A current challenge for tissue engineering while restoring the function of diseased or damaged tissue is to customize the tissue according to the target area. Scaffold-free approaches usually yield spheroid shapes with the risk of necrosis at the center due to poor nutrient and oxygen diffusion. Here, we used magnetic forces developed at the cellular scale by miniaturized magnets to create rod-shaped aggregates of stem cells that subsequently matured into a tissue-like structure. However, during the maturation process, the tissue-rods spontaneously bent and coiled into sphere-like structures, triggered by the increasing cell-cell adhesion within the initially non-homogeneous tissue. Optimisation of the intra-tissular magnetic forces successfully hindered the transition, in order to produce stable rod-shaped stem cells aggregates.

  9. Starch-degrading enzymes from anaerobic non-clostridial bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Weber, H; Schepers, H J; Troesch, W [Fraunhofer-Institut fuer Grenzflaechen- und Bioverfahrenstechnik (IGB), Stuttgart (Germany, F.R.)


    A number of meso- and thermophilic anaerobic starch-degrading non-spore-forming bacteria have been isolated. All the isolates belonging to different genera are strictly anaerobic, as indicated by a catalase-negative reaction, and produce soluble starch-degrading enzymes. Compared to enzymes of aerobic bacteria, those of anaerobic origin mainly show low molecular mass of about 25 000 daltons. Some of the enzymes may have useful applications in the starch industry because of their unusual product pattern, yielding maltotetraose as the main hydrolysis product. (orig.).

  10. Understanding the structural differences between spherical and rod-shaped human insulin nanoparticles produced by supercritical fluids precipitation. (United States)

    Park, Yeonju; Seo, Yongil; Chae, Boknam; Pyo, Dongjin; Chung, Hoeil; Hwang, Hyonseok; Jung, Young Mee


    In this study, the thermal denaturation mechanism and secondary structures of two types of human insulin nanoparticles produced by a process of solution-enhanced dispersion by supercritical fluids using dimethyl sulfoxide (DMSO) and ethanol (EtOH) solutions of insulin are investigated using spectroscopic approaches and molecular dynamics calculations. First, the temperature-dependent IR spectra of spherical and rod-shaped insulin nanoparticles prepared from DMSO and EtOH solution, respectively, are analyzed using principal component analysis (PCA) and 2D correlation spectroscopy to obtain a deeper understanding of the molecular structures and thermal behavior of the two insulin particle shapes. All-atom molecular dynamics (AAMD) calculations are performed to investigate the influence of the solvent molecules on the production of the insulin nanoparticles and to elucidate the geometric differences between the two types of nanoparticles. The results of the PCA, the 2D correlation spectroscopic analysis, and the AAMD calculations clearly reveal that the thermal denaturation mechanisms and the degrees of hydrogen bonding in the spherical and rod-shaped insulin nanoparticles are different. The polarity of the solvent might not alter the structure or function of the insulin produced, but the solvent polarity does influence the synthesis of different shapes of insulin nanoparticles. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Hydraulic fracture conductivity: effects of rod-shaped proppant from lattice-Boltzmann simulations and lab tests (United States)

    Osiptsov, Andrei A.


    The goal of this study is to evaluate the conductivity of random close packings of non-spherical, rod-shaped proppant particles under the closure stress using numerical simulation and lab tests, with application to the conductivity of hydraulic fractures created in subterranean formation to stimulate production from oil and gas reservoirs. Numerical simulations of a steady viscous flow through proppant packs are carried out using the lattice Boltzmann method for the Darcy flow regime. The particle packings were generated numerically using the sequential deposition method. The simulations are conducted for packings of spheres, ellipsoids, cylinders, and mixtures of spheres with cylinders at various volumetric concentrations. It is demonstrated that cylinders provide the highest permeability among the proppants studied. The dependence of the nondimensional permeability (scaled by the equivalent particle radius squared) on porosity obtained numerically is well approximated by the power-law function: K /Rv2 = 0.204ϕ4.58 in a wide range of porosity: 0.3 ≤ ϕ ≤ 0.7. Lattice-Boltzmann simulations are cross-verified against finite-volume simulations using Navier-Stokes equations for inertial flow regime. Correlations for the normalized beta-factor as a function of porosity and normalized permeability are presented as well. These formulae are in a good agreement with the experimental measurements (including packings of rod-shaped particles) and existing laboratory data, available in the porosity range 0.3 ≤ ϕ ≤ 0.5. Comparison with correlations by other authors is also given.

  12. Rod-shaped ion exchanger useful for purifying liquids or recovering components from liquids comprises a metal wire core surrounded by an ion-exchange resin

    NARCIS (Netherlands)

    Koopman, C.; Witkamp, G.J.


    Rod-shaped ion exchanger comprises a metal wire core surrounded by an ion-exchange resin. Independent claims are also included for: (1) a module comprising a housing with an inlet and outlet and one or more ion exchangers as above; (2) a process for producing an ion exchanger as above, comprising

  13. Chlamydia co-opts the rod shape-determining proteins MreB and Pbp2 for cell division. (United States)

    Ouellette, Scot P; Karimova, Gouzel; Subtil, Agathe; Ladant, Daniel


    Chlamydiae are obligate intracellular bacterial pathogens that have extensively reduced their genome in adapting to the intracellular environment. The chlamydial genome contains only three annotated cell division genes and lacks ftsZ. How this obligate intracellular pathogen divides is uncharacterized. Chlamydiae contain two high-molecular-weight (HMW) penicillin binding proteins (Pbp) implicated in peptidoglycan synthesis, Pbp2 and Pbp3/FtsI. We show here, using HMW Pbp-specific penicillin derivatives, that both Pbp2 and Pbp3 are essential for chlamydial cell division. Ultrastructural analyses of antibiotic-treated cultures revealed distinct phenotypes: Pbp2 inhibition induced internal cell bodies within a single outer membrane whereas Pbp3 inhibition induced elongated phenotypes with little internal division. Each HMW Pbp interacts with the Chlamydia cell division protein FtsK. Chlamydiae are coccoid yet contain MreB, a rod shape-determining protein linked to Pbp2 in bacilli. Using MreB-specific antibiotics, we show that MreB is essential for chlamydial growth and division. Importantly, co-treatment with MreB-specific and Pbp-specific antibiotics resulted in the MreB-inhibited phenotype, placing MreB upstream of Pbp function in chlamydial cell division. Finally, we showed that MreB also interacts with FtsK. We propose that, in Chlamydia, MreB acts as a central co-ordinator at the division site to substitute for the lack of FtsZ in this bacterium. © 2012 Blackwell Publishing Ltd.

  14. Modified two-step emulsion solvent evaporation technique for fabricating biodegradable rod-shaped particles in the submicron size range. (United States)

    Safari, Hanieh; Adili, Reheman; Holinstat, Michael; Eniola-Adefeso, Omolola


    Though the emulsion solvent evaporation (ESE) technique has been previously modified to produce rod-shaped particles, it cannot generate small-sized rods for drug delivery applications due to the inherent coupling and contradicting requirements for the formation versus stretching of droplets. The separation of the droplet formation from the stretching step should enable the creation of submicron droplets that are then stretched in the second stage by manipulation of the system viscosity along with the surface-active molecule and oil-phase solvent. A two-step ESE protocol is evaluated where oil droplets are formed at low viscosity followed by a step increase in the aqueous phase viscosity to stretch droplets. Different surface-active molecules and oil phase solvents were evaluated to optimize the yield of biodegradable PLGA rods. Rods were assessed for drug loading via an imaging agent and vascular-targeted delivery application via blood flow adhesion assays. The two-step ESE method generated PLGA rods with major and minor axis down to 3.2 µm and 700 nm, respectively. Chloroform and sodium metaphosphate was the optimal solvent and surface-active molecule, respectively, for submicron rod fabrication. Rods demonstrated faster release of Nile Red compared to spheres and successfully targeted an inflamed endothelium under shear flow in vitro and in vivo. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Phase diagrams and morphological evolution in wrapping of rod-shaped elastic nanoparticles by cell membrane: A two-dimensional study (United States)

    Yi, Xin; Gao, Huajian


    A fundamental understanding of cell-nanomaterial interaction is essential for biomedical diagnostics, therapeutics, and nanotoxicity. Here, we perform a theoretical analysis to investigate the phase diagram and morphological evolution of an elastic rod-shaped nanoparticle wrapped by a lipid membrane in two dimensions. We show that there exist five possible wrapping phases based on the stability of full wrapping, partial wrapping, and no wrapping states. The wrapping phases depend on the shape and size of the particle, adhesion energy, membrane tension, and bending rigidity ratio between the particle and membrane. While symmetric morphologies are observed in the early and late stages of wrapping, in between a soft rod-shaped nanoparticle undergoes a dramatic symmetry breaking morphological change while stiff and rigid nanoparticles experience a sharp reorientation. These results are of interest to the study of a range of phenomena including viral budding, exocytosis, as well as endocytosis or phagocytosis of elastic particles into cells.

  16. Filtration behaviors of rod-shaped bacterial broths in unsteady-state phase of cross-flow filtration

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, T.; Usui, K.; Koda, K.; Nakanishi, K. [Okayama University, Okayama (Japan). Faculty of Engineering


    Filtration behaviors in the unsteady-state phase of crossflow filtration of broths of Bacillus subtilis, Escherichia coli, and Lactobacillus delbrueckii, which are rod-shaped, were studied from the viewpoint of the changes in the specific resistance and in the structure of the microbial cake formed on the membrane surface. The permeation flux followed the cake filtration law at the initial stage of the crossflow filtration of the broths of B. subtilis and E. coli, where the cells deposited randomly on the membrane. In the case of the crossflow filtration of a L. delbrueckii broth, the period of random deposition was shorter. The specific resistance for the cake formed at the initial stage agreed with that measured in dead-end filtration. Then, the specific resistance started to increase in comparison with that measured in dead-end filtration due to shear-induced arrangement of the cells. The extent of the increase in specific resistance became higher and the time taken to start the cell arrangement became shorter with increasing circulation flow rate. The increase in specific resistance due to the shear-induced arrangement was more appreciable in the crossflow filtration of the broth of L. delbrueckii than that of B. subtilis and E. coli. The average permeation flux was increased considerably by applying periodical backwashing with appropriate time intervals. The permeation flux was well predicted by the cake filtration law, since the cells deposited in a way similar to that for dead-end filtration during a sufficiently short period of crossflow filtration in a backwashing mode. 21 refs., 11 figs.

  17. Active Tube-Shaped Actuator with Embedded Square Rod-Shaped Ionic Polymer-Metal Composites for Robotic-Assisted Manipulation

    Directory of Open Access Journals (Sweden)

    Yanjie Wang


    Full Text Available This paper reports a new technique involving the design, fabrication, and characterization of an ionic polymer-metal composite- (IPMC- embedded active tube, which can achieve multidegree-of-freedom (MODF bending motions desirable in many applications, such as a manipulator and an active catheter. However, traditional strip-type IPMC actuators are limited in only being able to generate 1-dimensional bending motion. So, in this paper, we try to develop an approach which involves molding or integrating rod-shaped IPMC actuators into a soft silicone rubber structure to create an active tube. We modified the Nafion solution casting method and developed a complete sequence of a fabrication process for rod-shaped IPMCs with square cross sections and four insulated electrodes on the surface. The silicone gel was cured at a suitable temperature to form a flexible tube using molds fabricated by 3D printing technology. By applying differential voltages to the four electrodes of each IPMC rod-shaped actuator, MDOF bending motions of the active tube can be generated. Experimental results show that such IPMC-embedded tube designs can be used for developing robotic-assisted manipulation.

  18. Active Tube-Shaped Actuator with Embedded Square Rod-Shaped Ionic Polymer-Metal Composites for Robotic-Assisted Manipulation (United States)

    Liu, Jiayu; Zhu, Denglin; Chen, Hualing


    This paper reports a new technique involving the design, fabrication, and characterization of an ionic polymer-metal composite- (IPMC-) embedded active tube, which can achieve multidegree-of-freedom (MODF) bending motions desirable in many applications, such as a manipulator and an active catheter. However, traditional strip-type IPMC actuators are limited in only being able to generate 1-dimensional bending motion. So, in this paper, we try to develop an approach which involves molding or integrating rod-shaped IPMC actuators into a soft silicone rubber structure to create an active tube. We modified the Nafion solution casting method and developed a complete sequence of a fabrication process for rod-shaped IPMCs with square cross sections and four insulated electrodes on the surface. The silicone gel was cured at a suitable temperature to form a flexible tube using molds fabricated by 3D printing technology. By applying differential voltages to the four electrodes of each IPMC rod-shaped actuator, MDOF bending motions of the active tube can be generated. Experimental results show that such IPMC-embedded tube designs can be used for developing robotic-assisted manipulation. PMID:29770160

  19. A 2D/3D image analysis system to track fluorescently labeled structures in rod-shaped cells: application to measure spindle pole asymmetry during mitosis. (United States)

    Schmitter, Daniel; Wachowicz, Paulina; Sage, Daniel; Chasapi, Anastasia; Xenarios, Ioannis; Simanis; Unser, Michael


    The yeast Schizosaccharomyces pombe is frequently used as a model for studying the cell cycle. The cells are rod-shaped and divide by medial fission. The process of cell division, or cytokinesis, is controlled by a network of signaling proteins called the Septation Initiation Network (SIN); SIN proteins associate with the SPBs during nuclear division (mitosis). Some SIN proteins associate with both SPBs early in mitosis, and then display strongly asymmetric signal intensity at the SPBs in late mitosis, just before cytokinesis. This asymmetry is thought to be important for correct regulation of SIN signaling, and coordination of cytokinesis and mitosis. In order to study the dynamics of organelles or large protein complexes such as the spindle pole body (SPB), which have been labeled with a fluorescent protein tag in living cells, a number of the image analysis problems must be solved; the cell outline must be detected automatically, and the position and signal intensity associated with the structures of interest within the cell must be determined. We present a new 2D and 3D image analysis system that permits versatile and robust analysis of motile, fluorescently labeled structures in rod-shaped cells. We have designed an image analysis system that we have implemented as a user-friendly software package allowing the fast and robust image-analysis of large numbers of rod-shaped cells. We have developed new robust algorithms, which we combined with existing methodologies to facilitate fast and accurate analysis. Our software permits the detection and segmentation of rod-shaped cells in either static or dynamic (i.e. time lapse) multi-channel images. It enables tracking of two structures (for example SPBs) in two different image channels. For 2D or 3D static images, the locations of the structures are identified, and then intensity values are extracted together with several quantitative parameters, such as length, width, cell orientation, background fluorescence and

  20. Identification of multidrug-resistant bacteria and Bacillus cereus from ...

    African Journals Online (AJOL)

    However, B. cereus was isolated from the hands of three. HCWs. Table 1 shows species of bacteria isolated from. HCWs and ES in Elkhomes hospital. B. cereus is a Gram-positive spore-forming facultative- anaerobic rod-shaped organism that can be found in different types of soils and widely distributed in the environment.

  1. Electrochemical synthesis of SnCo alloy shells on orderly rod-shaped Cu current collectors as anode materials for lithium-ion batteries with enhanced performance

    Energy Technology Data Exchange (ETDEWEB)

    Zhan, Fangwei; Zhang, Hui, E-mail:; Qi, Yue; Wang, Jiazheng; Du, Ning; Yang, Deren


    Highlights: •Nanostructured SnCo/Cu electrodes have been successfully fabricated. •A simple electrodeposition approach was employed. •The Cu arrays offer large surface area and improve electronic/ionic conductivity. •The electrodes show improved performance as anode for Li-ion batteries. •The improved performance was attributed to the nanostructured current collectors. -- Abstract: In this article, we report a two-step electrodeposition method for the synthesis of Cu/SnCo core–shell rod-shaped arrays as anodes of lithium-ion batteries. Firstly, the arrayed Cu nanorods with diameters of 200 nm were fabricated on a Cu foil through an electrodeposition method with alumina oxide membrane (AAO) as the template. Secondly, the SnCo alloy shells were subsequently electrodeposited on the surface of the rod-shaped Cu arrays to form the hybrid nanostructures. These hybrid electrodes delivered the enhanced cyclic performance and high rate capability serving as the anode materials for lithium-ion batteries. The improved electrochemical performance might be attributed to the large surface-to-volume area, sufficient buffering space, and high electronic conductivity associated with these 3-dimensional (3D) nanostructures.

  2. Spin-phonon coupling in rod-shaped half-metallic CrO sub 2 ultrafine particles: a magnetic Raman scattering study

    CERN Document Server

    Yu, T; Sun, W X; Lin, J Y; Ding, J


    Half-metallic CrO sub 2 powder compact with rod-shaped nanoparticles was studied by micro-Raman scattering in the presence of an external magnetic field at room temperature (300 K). In the low-field region (H <= 250 mT), the frequency and intensity of the E sub g mode, an internal phonon mode of CrO sub 2 , increase dramatically with increase in the magnetic field, while the corresponding linewidth decreases. The above parameters become constant when the CrO sub 2 powder enters the saturation state at higher magnetic field. The pronounced anomalies of the Raman phonon parameters under a low magnetic field are attributed to the spin-phonon coupling enhanced by the magnetic ordering, which is induced by the external magnetic field. (letter to the editor)

  3. Table sugar as preparation and carbon coating reagent for facile synthesis and coating of rod-shaped MnO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Hashem, Ahmed M., E-mail: [National Research Centre, Inorganic Chemistry Department, Behoes St., Dokki, Cairo (Egypt); Abuzeid, Hanaa M. [National Research Centre, Inorganic Chemistry Department, Behoes St., Dokki, Cairo (Egypt); Nikolowski, Kristian; Ehrenberg, Helmut [Institute for Complex Materials, IFW Dresden, Helmholtzstr. 20, D-01069 Dresden (Germany)


    Rod-shaped {alpha}-MnO{sub 2} has been synthesized by a novel and facile wet chemical method using simple sugar and potassium permanganate. Redox reaction between KMnO{sub 4} and sucrose is carried out in an acidic medium. Acidic medium provides a reducing character to sucrose through its decomposition to elemental carbon. Carbon coating process was done using simple sugar also as a source for carbon in an absolute ethanol with heating the mixture of {alpha}-MnO{sub 2} and sugar at 350 {sup o}C for an hour in an ambient atmosphere. A single phase of cryptomelane-like phase MnO{sub 2} was observed from XRD patterns for bare and carbon coated samples. TGA analysis shows the presence of carbon layer through more weight loss percent of carbon coated sample in comparison with that of carbon free MnO{sub 2}. Both virgin and carbon coated MnO{sub 2} have high thermal stability due to high percent of K inside the tunnel determined from ICP analysis. Transmission Electron Microscope (TEM) showed a rod-shaped crystal for both the parent and carbon coated {alpha}-MnO{sub 2} and confirmed the presence of a thin film of carbon around MnO{sub 2} particles. Both XRD and TEM investigations show that the prepared powders are in nano-scale. Initial capacity of about 140 mAh/g was obtained for the parent and carbon coated samples. The results show also that carbon coating process improves the capacity retention and the efficiency of {alpha}-MnO{sub 2} in comparison with that carbon free sample.

  4. Identification of marine methanol-utilizing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, M; Iwaki, H; Kouno, K; Inui, T


    A taxonomical study of 65 marine methanol-utilizing bacteria is described. They were Gram-negative, non-spore-forming rods with a polar flagellum and had marine bacterial properties and required vitamin B/sub 12/ for growth. All of them assimilated fructose in addition to C/sub 1/-compounds and produced acid oxidatively from fructose. Twenty-four strains assimilated only C/sub 1/-compounds. They were resistant to penicillin, oxytetracycline and 0/129 substance (Vibrio stat), and tolerant to 12% NaCl. Guanine-cytosine contents of deoxyribonucleic acid in typical strains fell in the range of 43.8 to 47.6%. Other morphological and physiological properties were almost the same as those of terrestrial methanol-utilizers. Bacteria in the first group (41 strains) were facultative methylotrophs and were divided into three subgroups by the assimilation of methylated amines, that is, subgroup I (30 strains) assimilated mono-, di- and tri-methylamine, subgroup II (9 strains) assimilated only mono-methylamine, the bacteria of subgroups I and II were named Alteromonas thalassomethanolica sp. nov. and subgroup III (2 strains) did not assimilate methylated amines, and was tentatively assigned as Alteromonas sp. The second group of bacteria (24 strains) was obligate methylotrophs, named Methylomonas thalassica sp. nov. and was divided into subgroup IV (15 strains) which assimilated mono-, di and tri-methylamine and subgroup V (9 strains) which assimilated mono-methylamine.

  5. The predominant circular form of avocado sunblotch viroid accumulates in planta as a free RNA adopting a rod-shaped secondary structure unprotected by tightly bound host proteins. (United States)

    López-Carrasco, Amparo; Flores, Ricardo


    Avocado sunblotch viroid (ASBVd), the type member of the family Avsunviroidae, replicates and accumulates in chloroplasts. Whether this minimal non-protein-coding circular RNA of 246-250 nt exists in vivo as a free nucleic acid or closely associated with host proteins remains unknown. To tackle this issue, the secondary structures of the monomeric circular (mc) (+) and (-) strands of ASBVd have been examined in silico by searching those of minimal free energy, and in vitro at single-nucleotide resolution by selective 2'-hydroxyl acylation analysed by primer extension (SHAPE). Both approaches resulted in predominant rod-like secondary structures without tertiary interactions, with the mc (+) RNA being more compact than its (-) counterpart as revealed by non-denaturing polyacryamide gel electrophoresis. Moreover, in vivo SHAPE showed that the mc ASBVd (+) form accumulates in avocado leaves as a free RNA adopting a similar rod-shaped conformation unprotected by tightly bound host proteins. Hence, the mc ASBVd (+) RNA behaves in planta like the previously studied mc (+) RNA of potato spindle tuber viroid, the type member of nuclear viroids (family Pospiviroidae), indicating that two different viroids replicating and accumulating in distinct subcellular compartments, have converged into a common structural solution. Circularity and compact secondary structures confer to these RNAs, and probably to all viroids, the intrinsic stability needed to survive in their natural habitats. However, in vivo SHAPE has not revealed the (possibly transient or loose) interactions of the mc ASBVd (+) RNA with two host proteins observed previously by UV irradiation of infected avocado leaves.

  6. Desulfuromonas svalbardensis sp. nov. and Desulfuromusa ferrireducens sp. nov., psychrophilic, Fe(III)-reducing bacteria isolated from Arctic sediments, Svalbard

    DEFF Research Database (Denmark)

    Vandieken, Verona; Mussmann, Marc; Niemann, Helge


    Two psychrophilic, Gram-negative, rod-shaped, motile bacteria (strains 112T and 102T) that conserved energy from dissimilatory Fe(III) reduction concomitant with acetate oxidation were isolated from permanently cold Arctic marine sediments. Both strains grew at temperatures down to -2 degrees C...

  7. Desulfuromonas svalbardensis sp nov and Desulfuromusa ferrireducens sp nov., psychrophilic, Fe(III)-reducing bacteria isolated from Arctic sediments, Svalbard

    DEFF Research Database (Denmark)

    Vandieken, V.; Mussmann, M.; Niemann, Hans Henrik


    Two psychrophilic, Gram-negative, rod-shaped, motile bacteria (strains 112(T) and 102(T)) that conserved energy from dissimilatory Fe(III) reduction concomitant with acetate oxidation were isolated from permanently cold Arctic marine sediments. Both strains grew at temperatures down to -2 degrees C...

  8. Thermophilic bacteria in Moroccan hot springs, salt marshes and desert soils


    Aanniz,Tarik; Ouadghiri,Mouna; Melloul,Marouane; Swings,Jean; Elfahime,Elmostafa; Ibijbijen,Jamal; Ismaili,Mohamed; Amar,Mohamed


    The diversity of thermophilic bacteria was investigated in four hot springs, three salt marshes and 12 desert sites in Morocco. Two hundred and forty (240) thermophilic bacteria were recovered, identified and characterized. All isolates were Gram positive, rod-shaped, spore forming and halotolerant. Based on BOXA1R-PCR and 16S rRNA gene sequencing, the recovered isolates were dominated by the genus Bacillus (97.5%) represented by B. licheniformis (119), B. aerius (44), B. sonorensis (33), B. ...

  9. Isolation and biochemical characterizations of the bacteria ...

    African Journals Online (AJOL)

    These isolates yielded off white convex colonies on potato dextrose agar (PDA) media at 29°C with 1.7 to 1.9 mm diameter and were yellow on yeast extract dextrose chalk agar (YDC) media at 27°C with 1.8 to 2.0 mm diameter. The bacteria were rod shape measuring 0.5 to 0.6 × 1.4 to 1.6 μm on PDA and 0.6 to 0.7 × 1.5 to ...

  10. Hygiene Aspects of the Biogas Process with Emphasis on Spore-Forming Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Bagge, Elisabeth


    Biogas is a renewable source of energy which can be obtained from processing of biowaste. The digested residues can be used as fertiliser. Biowaste intended for biogas production contains pathogenic micro-organisms. A pre-pasteurisation step at 70 deg C for 60 min before anaerobic digestion reduces non spore-forming bacteria such as Salmonella spp. To maintain the standard of the digested residues it must be handled in a strictly hygienic manner to avoid recontamination and re-growth of bacteria. The risk of contamination is particularly high when digested residues are transported in the same vehicles as the raw material. However, heat treatment at 70 deg C for 60 min will not reduce spore-forming bacteria such as Bacillus spp. and Clostridium spp. Spore-forming bacteria, including those that cause serious diseases, can be present in substrate intended for biogas production. The number of species and the quantity of Bacillus spp. and Clostridium spp. in manure, slaughterhouse waste and in samples from different stages during the biogas process were investigated. The number of species of clostridia seemed to decrease following digestion, likewise the quantity. However, Bacillus spp. seemed to pass unaffected through the biogas process. In laboratory-scale experiments the effects on clostridia during pasteurisation and digestion were investigated. Pathogenic clostridia were inoculated in substrates from homogenisation tanks and digester tanks. The inoculated clostridia remained after pasteurisation, but the impacts of digestion differ between different species. Culture followed by identification of C. chauvoei by PCR in samples from cattle died from blackleg, is faster and safer than culture followed by biochemical identification of C. chauvoei. However, for environmental samples the PCR method is not practically applicable for detection of C. chauvoei. To avoid spreading of diseases via biogas plants when digested residues are spread on arable land, a pasteurisation

  11. Pulling Helices inside Bacteria: Imperfect Helices and Rings (United States)

    Allard, Jun F.; Rutenberg, Andrew D.


    We study steady-state configurations of intrinsically-straight elastic filaments constrained within rod-shaped bacteria that have applied forces distributed along their length. Perfect steady-state helices result from axial or azimuthal forces applied at filament ends, however azimuthal forces are required for the small pitches observed for MreB filaments within bacteria. Helix-like configurations can result from distributed forces, including coexistence between rings and imperfect helices. Levels of expression and/or bundling of the polymeric protein could mediate this coexistence.

  12. 16S RRNA Gene Analysis of Chlorate Reducing Thermophilic Bacteria From Local Hot Spring


    Aminin, Agustina L. N; Katulistiwasari, Puri; Mulyani, Nies Suci


    Chlorates waste remediation by biological processes has been the object of current research. Strain CR, the chlorate reducing bacteria was isolated from Gedongsongo hot spring using minimal medium broth containing chlorates and acetate at 55oC. The determination of chlorate reduction from medium was carried out using turbidimetric method. CR isolate showed reducing ability 18% after four days of incubation. The phenotypic character of CR isolate including rod-shaped cells, gram-positive bacte...

  13. Investigation of Synthesis and Magnetic Properties of Rod-Shaped CoFe2O4 via Precipitation-Topotactic Reaction Employing α-FeOOH and γ-FeOOH As Templates (United States)

    Cao, Xiaohui; Dong, Hongfei; Tan, Yuzhuo; Meng, Jinhong


    Rod-shaped CoFe2O4 was prepared by chemical precipitation-topotactic reaction method, and in this preparation needle-like γ-FeOOH and α-FeOOH were synthesized to use as template materials. The evolution of phase and morphology in the process of calcination exhibits that α-FeOOH and γ-FeOOH experienced different routes to form the α-Fe2O3 middle phase with different crystallinity and morphology. The synthesis process of CoFe2O4 revealed that the crystallinity, purity and morphology of CoFe2O4 depend on the α-Fe2O3 middle phase. The magnetic measurement showed that the CoFe2O4 prepared from α-FeOOH has higher saturation magnetization and coercivity, and the crystallinity and morphology may play important roles in achieving a better magnetic performance.

  14. Enhanced bioleaching on attachment of indigenous acidophilic bacteria to pyrite surface (United States)

    Wi, D. W.; Cho, K. H.; Kim, B. J.; Choi, N. C.; Park, C. Y.


    In recent years, bioleaching has been widely applied on an industrial scale due to the advantages of low cost and environment friendliness. The direct contact mechanism of bioleaching assumes the action of a metal sulfide-attached cell oxidizing the mineral by an enzyme system with oxygen to sulfate and metal cations. Fundamental surface properties of sulfide particles and leaching-bacteria in bioleaching play the key role in the efficiency of this process. The aim of this work is to investigate of direct contact bioleaching mechanism on pyrite through attachment properties between indigenous acidophilic bacteria and pyrite surfaces. The bacteria were obtained from sulfur hot springs, Hatchobaru thermal electricity plant in Japan. And pyrite was collected from mine waste from Gwang-yang abandoned gold mines, Korea. In XRD analyses of the pyrite, x-ray diffracted d-value belong to pyrite was observed. The indigenous acidophilic bacteria grew well in a solution and over the course of incubation pH decreased and Eh increased. In relation to a bacterial growth-curve, the lag phase was hardly shown while the exponential phase was very fast. Bioleaching experiment result was showed that twenty days after the indigenous acidophilic bacteria were inoculated to a pyrite-leaching medium, the bacterial sample had a greater concentration of Fe and Zn than within the control sample. In SEM-EDS analyses, rod-shaped bacteria and round-shaped microbes were well attached to the surface of pyrite. The size of the rod-shaped bacteria ranged from 1.05~1.10 ? to 4.01~5.38 ?. Round-shaped microbes were more than 3.0 ? in diameter. Paired cells of rod-shaped bacteria were attached to the surface of pyrite linearly.

  15. Pseudomonas tarimensis sp. nov., an endophytic bacteria isolated from Populus euphratica. (United States)

    Anwar, Nusratgul; Rozahon, Manziram; Zayadan, Bolatkhan; Mamtimin, Hormathan; Abdurahman, Mehfuzem; Kurban, Marygul; Abdurusul, Mihribangul; Mamtimin, Tursunay; Abdukerim, Muhtar; Rahman, Erkin


    An endophytic bacterium, MA-69 T , was isolated from the storage liquid in the stems of Populuseuphratica trees at the ancient Ugan River in Xinjiang, PR China. Strain MA-69 T was found to be short rod-shaped, Gram-stain-negative, non-spore-forming, aerobic and motile by means of a monopolar flagellum. According to phylogenetic analysis based on 16S rRNA gene sequences, strain MA-69 T was assigned to the genus Pseudomonas with highest 16S rRNA gene sequence similarity of 97.5 % to Pseudomonas azotifigens JCM 12708 T , followed by Pseudomonas matsuisoli JCM 30078 T (97.5 %), Pseudomonas balearica DSM 6083 T (97.1 %), Azotobacter salinestris ATCC 49674 T (96.1 %) and Pseudomonas indica DSM 14015 T (95.9 %). Analysis of strain MA-69 T based on the three housekeeping genes, rpoB, rpoD and gyrB, further confirmed the isolate to be distinctly delineated from species of the genus Pseudomonas. The DNA G+C content of strain MA-69 T was 64.1 mol%. DNA-DNA hybridization with Pseudomonas azotifigens JCM 12708 T , Pseudomonas matsuisoli JCM 30078 T and Pseudomonas balearica DSM 6083 T revealed 62.9, 60.1 and 49.0 % relatedness, respectively. The major fatty acids in strain MA-69 T were summed feature 3 (25.7 %), summed feature 8 (24.0 %), C19 : 0cyclo ω8c (19.9 %), C16 : 0 (14.6 %) and C12 : 0 (6.3 %). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. Q-9 was the major quinone in strain MA-69 T . Based on phenotypic, chemotaxonomic and phylogenetic properties, strain MA-69 T represents a novel species of the genus Pseudomonas, for which the name Pseudomonas tarimensis sp. nov. is proposed. The type strain is MA-69 T (=CCTCC AB 2013065 T =KCTC 42447 T ).

  16. 新型包覆式双材质杆状EFP成型的数值仿真研究%Numerical simulation of new wrapping double-material rod-shaped EFP forming

    Institute of Scientific and Technical Information of China (English)

    黄松; 尹建平; 孙加肖


    In order to improve the damage to light armor at close range (4-5 times charge caliber),a kind of wrapping doublematerial liner was designed based on the damage mechanism of PELE.Using ANSYS/LS-DYNA software,the influence of the cone angle,the charge length-to-diameter ratio and the rate of liner thickness on EFP forming was studied based on the liner of large cone angle and variable-wall-thickness.The forming effect was compared and analyzed to obtain the optimal structure.The results show that charge length-to-diameter ratio is the main factor influencing the EFP velocity,cone angle is the main factor influencing the EFP length-to-diameter ratio.The shape of the EFP is preferable when the cone angle is about 149°,the charge length-to-diameter ratio is 0.8,the rate of liner thickness is about 10.0%,and the EFP steady speed is 2 598 m/s.Finally,the simulation on traditional single-material rod-shaped EFP and the new double-material rod-shaped EFP penetrating target was carried out.It is concluded that the new EFP can produce a lateral efficiency similar to PELE when penetrating target,which has greater damage ability to target than the single-material rod-shaped EFP.%为提高对近距离(4~5倍装药口径)轻型装甲的毁伤,基于PELE毁伤机理设计了一种包覆式双材质药型罩.运用ANSYS/LS-DYNA软件对大锥角变壁厚药型罩形成EFP进行数值仿真,研究药型罩锥角与装药长径比以及壁厚变化率对EFP成型的影响,对比分析其成型效果以得到较理想的侵彻体装药结构.结果表明:装药长径比是影响EFP速度的主要因素,锥角是影响EFP长径比的主要因素;药型罩锥角为149°左右、壁厚变化率为10.0%左右、装药长径比为0.8时可以形成较理想的杆状EFP,此时EFP的稳定速度约为2 598 m/s.最后通过传统单材质杆状EFP和该新型双材质杆状EFP侵彻靶板仿真,得出该新型包覆式双材质杆状EFP在侵彻靶板时能够产生类似PELE的横

  17. Screening and biological characteristics of fufenozide degrading bacteria (United States)

    Xu, Chenhao; Gong, Mingfu; Guan, Qinlan; Deng, Xia; Deng, Hongyan; Huang, Jiao


    Fufenozide was a novel pesticide for the control of Lepidoptera pests, which was highly toxic to silkworm. Fufenozide-contaminated soil samples were collected and the bacteria that degrade fufenozide were isolated and screened by selective medium. The colony characteristics, cell characteristics and degradation characteristics in different concentrations fufenozide of the fufenozide degrading bacteria were studied. The results indicated that seven strains of fufenozide degradeing bacteria, named as DDH01, DDH03, DDH04, DDH04, DDH05, DDH07 and DDH07 respectively, were isolated from soil contaminated with fufenozide. DDH01, DDH02, DDH04 and DDH05 of seven fufenozide degrading bacteria, was gram-positive bacteria, and DDH03, DDH06 and DDH07 was gram-negative bacteria. All of seven strains of fufenozide degrading bacteria were not spores, weeks flagella, rod-shaped bacteria. DDH06 and DDH07 had capsules, and the remaining five strains had not capsule. The colonies formed by seven strains of fufenozide degradation bacteria on beef extract peptone medium plate were milky white colonies with irregular edges, thinner lawn, smaller colony with smooth surface. The growth of 7 strains of fufenozide degradation bacteria was significantly affected by the concentration of fufenozide, All of 7 strains grown in the range from 0.00025 g/mL to 1 g/mL of 10% fufenozide suspension. DDH2 was the best among the 7 strains of fufenozide degrading bacteria grown in 10% fufenozide suspension medium.

  18. The new species Enterobacter oryziphilus sp nov and Enterobacter oryzendophyticus sp nov are key inhabitants of the endosphere of rice

    NARCIS (Netherlands)

    Hardoim, Pablo Rodrigo; Nazir, Rashid; Sessitsch, Angela; Elhottova, Dana; Korenblum, Elisa; van Overbeek, Leonard Simon; van Elsas, Jan Dirk


    Background: Six independent Gram-negative, facultatively anaerobic, non-spore-forming, nitrogen-fixing rod-shaped isolates were obtained from the root endosphere of rice grown at the International Rice Research Institute (IRRI) and investigated in a polyphasic taxonomic study. Results: The strains

  19. The new species Enterobacter oryzaphilus sp. nov. and Enterobacter oryzaendophyticus sp. nov. are key inhabitants of the endosphere of rice.

    NARCIS (Netherlands)

    Hardoim, P.R.; Nazir, R.; Sessitsch, A.; Elhottova, D.; Korenblum, E.; Overbeek, van L.S.; Elsas, J.D.


    BACKGROUND: Six independent Gram-negative, facultatively anaerobic, non-spore-forming, nitrogen-fixing rod-shaped isolates were obtained from the root endosphere of rice grown at the International Rice Research Institute (IRRI) and investigated in a polyphasic taxonomic study.
    RESULTS: The

  20. Isolation and characterization of Caldicellulosiruptor lactoaceticus sp. nov., an extremely thermophilic, cellulolytic, anaerobic bacterium

    DEFF Research Database (Denmark)

    Mladenovska, Zuzana; Mathrani, Indra M.; Ahring, Birgitte Kiær


    An anaerobic, extremely thermophilic, cellulolytic, non-spore-forming bacterium, strain 6A, was isolated from an alkaline hot spring in Hverageroi, Iceland. The bacterium was non-motile, rod-shaped (1.5-3.5 x 0.7 mu m) and occurred singly, in pairs or in chains and stained gram-negative. The growth...

  1. Nioella nitratireducens gen. nov., sp. nov., a novel member of the family Rhodobacteraceae isolated from Azorean Island

    Digital Repository Service at National Institute of Oceanography (India)

    Rajasabapathy, R.; Mohandass, C; Yoon, J; Dastager, S.G.; Liu, Q.; Khieu, T.-N.; Son, C; Li, W.-J; Colaco, A.

    A novel Gram-negative, non-spore forming, rod-shaped aerobic bacterium, designated SSW136T, was isolated from a surface seawater sample collected at Espalamaca (in Faial Island), Azores. Growth was found to occur from 10 to 37 °C, pH 6...

  2. Roseovarius azorensis sp. nov., isolated from seawater at Espalamaca, Azores

    Digital Repository Service at National Institute of Oceanography (India)

    Rajasabapathy, R.; Mohandass, C; Dastager, S.G.; Liu, Q.; Khieu, T.-N.; Son, C; Li, W.-J; Colaco, A.

    A Gram-negative, motile, non-spore forming, rod shaped aerobic bacterium, designated strain SSW084T, was isolated from a surface seawater sample collected at Espalamaca (38°33`N; 28°39`W), Azores. Growth was found to occur from 15 to 40...

  3. Marinicella sediminis sp. nov., isolated from marine sediment (United States)

    A novel heterotrophic, Gram-stain-negative, aerobic, rod-shaped, pale yellow, non-motile and non-spore-forming bacterium, designated as strain F2**T, was isolated from the marine sediment collected from Weihai coastal, Shandong Province, PR China. Optimal growth occurred at 33 °C (range 10–37 °C), w...

  4. Wenzhouxiangella sediminis sp. nov. isolated from coastal sediment (United States)

    A novel Gram-stain-negative, non-spore-forming, no flagellum, facultatively anaerobic, oxidase-negative, catalase- positive, rod-shaped strain, designated XDB06**T, was isolated from coastal sediment of Xiaoshi Island, Weihai, China. Optimal growth occurred at 37 °C, pH 7.5 and with 4.0% (w/v) NaCl....

  5. Natural Diversity in Heat Resistance of Bacteria and Bacterial Spores: Impact on Food Safety and Quality. (United States)

    den Besten, Heidy M W; Wells-Bennik, Marjon H J; Zwietering, Marcel H


    Heat treatments are widely used in food processing often with the aim of reducing or eliminating spoilage microorganisms and pathogens in food products. The efficacy of applying heat to control microorganisms is challenged by the natural diversity of microorganisms with respect to their heat robustness. This review gives an overview of the variations in heat resistances of various species and strains, describes modeling approaches to quantify heat robustness, and addresses the relevance and impact of the natural diversity of microorganisms when assessing heat inactivation. This comparison of heat resistances of microorganisms facilitates the evaluation of which (groups of) organisms might be troublesome in a production process in which heat treatment is critical to reducing the microbial contaminants, and also allows fine-tuning of the process parameters. Various sources of microbiological variability are discussed and compared for a range of species, including spore-forming and non-spore-forming pathogens and spoilage organisms. This benchmarking of variability factors gives crucial information about the most important factors that should be included in risk assessments to realistically predict heat inactivation of bacteria and spores as part of the measures for controlling shelf life and safety of food products.

  6. Survival and Recovery of Methanotrophic Bacteria Starved Under Oxic and Anoxic Conditions (United States)

    Roslev, Peter; King, Gary M.


    The effects of carbon deprivation on survival of methanotrophic bacteria were compared in cultures incubated in the presence and absence of oxygen in the starvation medium. Survival and recovery of the examined methanotrophs were generally highest for cultures starved under anoxic conditions as indicated by poststarvation measurements of methane oxidation, tetrazolium salt reduction, plate counts, and protein synthesis. Methylosinus trichosporium OB3b survived up to 6 weeks of carbon deprivation under anoxic conditions while maintaining a physiological state that allowed relatively rapid (hours) methane oxidation after substrate addition. A small fraction of cells starved under oxic and anoxic conditions (4 and 10%, respectively) survived more than 10 weeks but required several days for recovery on plates and in liquid medium. A non-spore-forming methanotroph, strain WP 12, displayed 36 to 118% of its initial methane oxidation capacity after 5 days of carbon deprivation. Oxidation rates varied with growth history prior to the experiments as well as with starvation conditions. Strain WP 12 starved under anoxic conditions showed up to 90% higher methane oxidation activity and 46% higher protein production after starvation than did cultures starved under oxic conditions. Only minor changes in biomass and niorpholow were seen for methanotrophic bacteria starved tinder anoxic conditions. In contrast, starvation under oxic conditions resulted in morphology changes and an initial 28 to 35% loss of cell protein. These data suggest that methanotrophic bacteria can survin,e carbon deprivation under anoxic conditions by using maintenance energy derived Solelyr from an anaerobic endogenous metabolism. This capability could partly explain a significant potential for methane oxidation in environments not continuously, supporting aerobic methanotrophic growth.

  7. Bacteria belonging to the genus Burkholderia are obligatory symbionts of the eriococcids Acanthococcus aceris Signoret, 1875 and Gossyparia spuria (Modeer, 1778) (Insecta, Hemiptera, Coccoidea). (United States)

    Michalik, Katarzyna; Szklarzewicz, Teresa; Kalandyk-Kołodziejczyk, Małgorzata; Jankowska, Władysława; Michalik, Anna


    In the fat body cells of the scale insects, Gossyparia spuria and Acanthococcus aceris, numerous rod-shaped symbiotic bacteria occur. Molecular analyses have revealed that these microorganisms are closely related to the widely distributed bacterium Burkholderia. Ultrastructural observations have revealed that the bacteria are transovarially (vertically) transmitted from the mother to offspring. The microorganisms leave the fat body cells and invade ovarioles containing vitellogenic oocytes. They pass through the follicular epithelium in the neck region of the ovariole and enter the perivitelline space. Next, the symbionts infest the anterior region of the oocyte. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Cell wall elongation mode in Gram-negative bacteria is determined by peptidoglycan architecture. (United States)

    Turner, Robert D; Hurd, Alexander F; Cadby, Ashley; Hobbs, Jamie K; Foster, Simon J


    Cellular integrity and morphology of most bacteria is maintained by cell wall peptidoglycan, the target of antibiotics essential in modern healthcare. It consists of glycan strands, cross-linked by peptides, whose arrangement determines cell shape, prevents lysis due to turgor pressure and yet remains dynamic to allow insertion of new material, and hence growth. The cellular architecture and insertion pattern of peptidoglycan have remained elusive. Here we determine the peptidoglycan architecture and dynamics during growth in rod-shaped Gram-negative bacteria. Peptidoglycan is made up of circumferentially oriented bands of material interspersed with a more porous network. Super-resolution fluorescence microscopy reveals an unexpected discontinuous, patchy synthesis pattern. We present a consolidated model of growth via architecture-regulated insertion, where we propose only the more porous regions of the peptidoglycan network that are permissive for synthesis.

  9. Genotypic and Phylogenic Analysis of Lactobacilli Producing Bacteriocin Isolated from Traditional Dairy Products and Food

    Directory of Open Access Journals (Sweden)

    Frazaneh Tafvizi


    Full Text Available Background & Objective: Lactic acid bacteria (LAB are a group of Gram-positive, non-spore forming, cocci or rod shaped, catalase negative organisms, considered as Generally Recognized as Safe (GRAS organisms. These bacteria are used for thousands of years for production of fermented foods because of their ability to produce desirable changes in taste, flavor and texture. Different antimicrobial molecules such as bacteriocins produced by these bacteria that can inhibit food pathogens, so enhancing the shelf life and improving the safety of food products. Because of important role of LAB to improving the human health, molecular identification and phylogenic analysis of these bacteria based on 16S rRNA sequencing play the critical role in investigation of local sources of LAB in Iran. Materials & Methods: 5 isolates were selected from 20 isolates for molecular identification. These strains produced the high level of bacteriocin. Total genomic DNA was extracted by lysosyme extraction protocol. PCR-mediated amplification was carried out by degenerate primers. Sequencing was performed after purification of PCR product. Results: Isolates were deposited as novel strains of Lactobacillus casei and Entrococcus facium in GenBank. Conclusion: Because of high potential of local probiotic bacteria in Iran, these strains may be useful and could be used in the food industry.

  10. Effect of adaptation and pulp density on bioleaching of mine waste using indigenous acidophilic bacteria (United States)

    Cho, K.; Kim, B.; Lee, D.; Choi, N.; Park, C.


    Adaptation to environment is a natural phenomena that takes place in many animals, plants and microorganisms. These adapted organisms achieve stronger applicability than unadapted organisms after habitation in a specific environment for a long time. In the biohydrometallurgical industry, adaptation to special environment conditions by selective culturing is the most popular method for improving bioleaching activity of strains-although that is time consuming. This study investigated the influence of the bioleaching efficiency of mine waste under batch experimental conditions (adaptation and pulp density) using the indigenous acidophilic bacteria collected from acid mine drainage in Go-seong and Yeon-hwa, Korea. We conducted the batch experiments at the influences of parameters, such as the adaptation of bacteria and pulp density of the mine waste. In the adaptation case, the value of pH in 1'st adaptation bacteria sample exhibited lower than in 2'nd adaptation bacteria sample. And the content of both Cu and Zn at 1'st adaptation bacteria sample appeared lower than at 2'nd adaptation bacteria sample. In the SEM analysis, the rod-shaped bacteria with 1μm in length were observed on the filter paper (pore size - 0.45μm). The results of pulp density experiments revealed that the content of both Cu and Zn increased with increasing pulp density, since the increment of pulp density resulted in the enhancement of bioleaching capacity.

  11. Constant Flux of Spatial Niche Partitioning through High-Resolution Sampling of Magnetotactic Bacteria. (United States)

    He, Kuang; Gilder, Stuart A; Orsi, William D; Zhao, Xiangyu; Petersen, Nikolai


    Magnetotactic bacteria (MTB) swim along magnetic field lines in water. They are found in aquatic habitats throughout the world, yet knowledge of their spatial and temporal distribution remains limited. To help remedy this, we took MTB-bearing sediment from a natural pond, mixed the thoroughly homogenized sediment into two replicate aquaria, and then counted three dominant MTB morphotypes (coccus, spirillum, and rod-shaped MTB cells) at a high spatiotemporal sampling resolution: 36 discrete points in replicate aquaria were sampled every ∼30 days over 198 days. Population centers of the MTB coccus and MTB spirillum morphotypes moved in continual flux, yet they consistently inhabited separate locations, displaying significant anticorrelation. Rod-shaped MTB were initially concentrated toward the northern end of the aquaria, but at the end of the experiment, they were most densely populated toward the south. The finding that the total number of MTB cells increased over time during the experiment argues that population reorganization arose from relative changes in cell division and death and not from migration. The maximum net growth rates were 10, 3, and 1 doublings day -1 and average net growth rates were 0.24, 0.11, and 0.02 doublings day -1 for MTB cocci, MTB spirilla, and rod-shaped MTB, respectively; minimum growth rates for all three morphotypes were -0.03 doublings day -1 Our results suggest that MTB cocci and MTB spirilla occupy distinctly different niches: their horizontal positioning in sediment is anticorrelated and under constant flux. IMPORTANCE Little is known about the horizontal distribution of magnetotactic bacteria in sediment or how the distribution changes over time. We therefore measured three dominant magnetotactic bacterium morphotypes at 36 places in two replicate aquaria each month for 7 months. We found that the spatial positioning of population centers changed over time and that the two most abundant morphotypes (MTB cocci and MTB spirilla

  12. Bioleaching of electronic waste using bacteria isolated from the marine sponge Hymeniacidon heliophila (Porifera). (United States)

    Rozas, Enrique E; Mendes, Maria A; Nascimento, Claudio A O; Espinosa, Denise C R; Oliveira, Renato; Oliveira, Guilherme; Custodio, Marcio R


    The bacteria isolated from Hymeniacidon heliophila sponge cells showed bioleaching activity. The most active strain, Hyhel-1, identified as Bacillus sp., was selected for bioleaching tests under two different temperatures, 30°C and 40°C, showing rod-shaped cells and filamentous growth, respectively. At 30°C, the bacteria secreted substances which linked to the leached copper, and at 40°C metallic nanoparticles were produced inside the cells. In addition, infrared analysis detected COOH groups and linear peptides in the tested bacteria at both temperatures. The Hyhel-1 strain in presence of electronic waste (e-waste) induced the formation of crust, which could be observed due to bacteria growing on the e-waste fragment. SEM-EDS measurements showed that the bacterial net surface was composed mostly of iron (16.1% w/w), while a higher concentration of copper was observed in the supernatant (1.7% w/w) and in the precipitated (49.8% w/w). The substances linked to copper in the supernatant were sequenced by MALDI-TOF-ms/ms and identified as macrocyclic surfactin-like peptides, similar to the basic sequence of Iturin, a lipopeptide from Bacillus subtilis. Finally, the results showed that Hyhel-1 is a bioleaching bacteria and cooper nanoparticles producer and that this bacteria could be used as a copper recovery tool from electronic waste. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Bacteria in the Tatahouine meteorite: nanometric-scale life in rocks. (United States)

    Gillet, P h; Barrat, J A; Heulin, T h; Achouak, W; Lesourd, M; Guyot, F; Benzerara, K


    We present a study of the textural signature of terrestrial weathering and related biological activity in the Tatahouine meteorite. Scanning and transmission electron microscopy images obtained on the weathered samples of the Tatahouine meteorite and surrounding soil show two types of bacteria-like forms lying on mineral surfaces: (1) rod-shaped forms (RSF) about 70-80 nm wide and ranging from 100 nm to 600 nm in length; (2) ovoid forms (OVF) with diameters between 70 and 300 nm. They look like single cells surrounded by a cell wall. Only Na, K, C, O and N with traces of P and S are observed in the bulk of these objects. The chemical analyses and electron diffraction patterns confirm that the RSF and OVF cannot be magnetite or other iron oxides, iron hydroxides, silicates or carbonates. The sizes of the RSF and OVF are below those commonly observed for bacteria but are very similar to some bacteria-like forms described in the Martian meteorite ALH84001. All the previous observations strongly suggest that they are bacteria or their remnants. This conclusion is further supported by microbiological experiments in which pleomorphic bacteria with morphology similar to the OVF and RSF objects are obtained from biological culture of the soil surrounding the meteorite pieces. The present results show that bacteriomorphs of diameter less than 100 nm may in fact represent real bacteria or their remnants.

  14. Processive movement of MreB-associated cell wall biosynthetic complexes in bacteria. (United States)

    Domínguez-Escobar, Julia; Chastanet, Arnaud; Crevenna, Alvaro H; Fromion, Vincent; Wedlich-Söldner, Roland; Carballido-López, Rut


    The peptidoglycan cell wall and the actin-like MreB cytoskeleton are major determinants of cell shape in rod-shaped bacteria. The prevailing model postulates that helical, membrane-associated MreB filaments organize elongation-specific peptidoglycan-synthesizing complexes along sidewalls. We used total internal reflection fluorescence microscopy to visualize the dynamic relation between MreB isoforms and cell wall synthesis in live Bacillus subtilis cells. During exponential growth, MreB proteins did not form helical structures. Instead, together with other morphogenetic factors, they assembled into discrete patches that moved processively along peripheral tracks perpendicular to the cell axis. Patch motility was largely powered by cell wall synthesis, and MreB polymers restricted diffusion of patch components in the membrane and oriented patch motion.

  15. A combined experimental and computational study of water-gas shift reaction over rod-shaped Ce0.75 M0.25O2 (M=Ti, Zr, and Mn) supported Cu catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Zhibo; Peng, Fei; Chen, Biaohua; Mei, Donghai; Li, Jianwei


    Water-gas shift (WGS) reaction over a series of ceria-based mixed oxides supported Cu catalysts was investigated using a combined experimental and theoretical method. The mixed rod-shaped Ce0.75M0.25O2 (M = Ti4+, Zr4+, Mn4+) solid solutions, which majorly expose the (110) and (100) facets, are synthesized by hydrothermal method and used to prepare supported Cu catalysts. We found that the Cu/Ce0.75Ti0.25O2 (Cu-CT) exhibits the highest CO conversion in the temperature range of 150-250 °C among all supported Cu catalysts. This is mainly attributed to (i) good dispersion of Cu; (ii) largest amount of moderate copper oxide; and (iii) strongest Cu-support interaction of Cu-CT. And compared to other mixed metals, periodic density functional theory calculations performed, this work further suggest that the introduction of Ti into CeO2 not only promotes oxygen vacancy formation and CO adsorption, but also facilitates the carboxyl (COOH) formation at the interface of the Cu cluster and the support, which leads to the enhanced catalytic activity of the Cu-CT toward WGS reaction.

  16. Phylogeny of the ammonia-producing ruminal bacteria Peptostreptococcus anaerobius, Clostridium sticklandii, and Clostridium aminophilum sp. nov (United States)

    Paster, B. J.; Russell, J. B.; Yang, C. M.; Chow, J. M.; Woese, C. R.; Tanner, R.


    In previous studies, gram-positive bacteria which grew rapidly with peptides or an amino acid as the sole energy source were isolated from bovine rumina. Three isolates, strains C, FT (T = type strain), and SR, were considered to be ecologically important since they produced up to 20-fold more ammonia than other ammonia-producing ruminal bacteria. On the basis of phenotypic criteria, the taxonomic position of these new isolates was uncertain. In this study, the 16S rRNA sequences of these isolates and related bacteria were determined to establish the phylogenetic positions of the organisms. The sequences of strains C, FT, and SR and reference strains of Peptostreptococcus anaerobius, Clostridium sticklandii, Clostridium coccoides, Clostridium aminovalericum, Acetomaculum ruminis, Clostridium leptum, Clostridium lituseburense, Clostridium acidiurici, and Clostridium barkeri were determined by using a modified Sanger dideoxy chain termination method. Strain C, a large coccus purported to belong to the genus Peptostreptococcus, was closely related to P. anaerobius, with a level of sequence similarity of 99.6%. Strain SR, a heat-resistant, short, rod-shaped organism, was closely related to C. sticklandii, with a level of sequence similarity of 99.9%. However, strain FT, a heat-resistant, pleomorphic, rod-shaped organism, was only distantly related to some clostridial species and P. anaerobius. On the basis of the sequence data, it was clear that strain FT warranted designation as a separate species. The closest known relative of strain FT was C. coccoides (level of similarity, only 90.6%). Additional strains that are phenotypically similar to strain FT were isolated in this study.(ABSTRACT TRUNCATED AT 250 WORDS).

  17. Technique for preparation of anaerobic microbes: Rodshaped cellulolytic bacteria

    Directory of Open Access Journals (Sweden)

    Amlius Thalib


    Full Text Available Preparation of anaerobic-rod cellulolytic bacteria with coating technique has been conducted. Steps of the processes involved were cultivation, coating, evaporation, and drying. Coating agent used was Gum Arabic, and drying techniquesconducted were freeze drying and sun drying. pH of culture media was firstly optimized to obtain the maximal population ofbacteria. Both coated and uncoated preparates were subjected to drying. Morphological and Gram type identifications showed that uncoated preparate dried with freeze drying is not contaminated (ie. all bacteria are rod shape with Gram-negative type while the one dried with sun drying is not morphologically pure (ie. containing of both rod and coccus shapes with Gram negative and positive. The coated preparates dried by both freeze and sun drying, were not contaminated (ie. all are rods with Gram-negative. The coating and drying processes decreased viability of preparates significantly. However, the decreasing of viability of coated preparate are lower than uncoated preparate (ie. 89 vs. 97%. Total count of bacteria in sun-drying coated preparate are higher (P<0.05 than the uncoated preparate (ie. 3.38 x 1010 vs. 1.97 x 1010 colony/g DM. Activity of sun-drying coated preparate to digest elephant grass and rice straw was higher (P<0.01 than the sun-drying uncoated preparate with the in vitro DMD values were 42.7 vs. 35.5% for elephant grass substrate and 29.3 vs. 24.6% for rice straw substrate. Therefore, it is concluded that coating technique has a positive effects on the preparation of rumen bacteria.

  18. Melting mechanism in monolayers of flexible rod-shaped molecules

    DEFF Research Database (Denmark)

    Hansen, Flemming Yssing; Taub, H.


    The melting of butane and hexane monolayers adsorbed on a graphite basal-plane surface has been studied by molecular-dynamics simulations and experimentally by neutron diffraction. The simulation results are qualitatively consistent with the observed diffraction patterns and suggest a general...

  19. Reactor core with rod-shaped fuel cells

    International Nuclear Information System (INIS)

    Dworak, A.


    The aim is an optimization of load distribution in the core so that the load decreases in the direction of coolant flow (with gas cooling from above downwards) but so that it remains constant in horizontal layers to the edge of the core. The former produces optimum cooling, because the coolant has to take up decreasing heat output in the direction of flow. The latter simplifies refueling, because replacement of a whole layer having the same burn-up takes place. The upper two layers with the highest output and the shortest dwell time are replaced every 300 days, for example, the third layer is replaced after double this time and 5 more layers after four times this dwell time. After the simultaneous replacement of all layers, the reactor is in the same state as at commissioning. The fuel cells consist of hexagonal graphite blocks about 1.65 metres in height and 0.75 wide, for example. Each block contains about 100 through cooling channels and about 200 fuel channels closed on both sides. A large number of columns each consisting of 8 blocks is arranged in a tight honeycomb pattern and forms the core. Within each of the 8 horizontal layers of blocks, each fuel cell contains the same fuel mixture with predetermined dwell time. The fuel mixture is suited to the dwell time planned for each layer. The various fuel cells are kept at the same output by burnable neutron poisons in special channels provided for this purpose in the fuel cell and/or by absorber rods, or a planned load distribution is maintained. (HP) [de

  20. Degradation and utilization of polycyclic aromatic hydrocarbons by indigenous soil bacteria

    International Nuclear Information System (INIS)

    Stetzenbach, L.D.A.


    The persistence of industrially derived polycyclic aromatic hydrocarbons in the subsurface may be significantly affected by the metabolism of soil bacteria. This study was conducted to determine the ability of indigenous soil bacteria to decrease the concentration of four polycyclic aromatic hydrocarbons (naphthalene, fluorene, anthracene, and pyrene) and to utilize the compounds as a substrate for growth. Soil cores from petroleum contaminated and noncontaminated sites contained 10 5 -10 7 viable microorganisms per gram dryweight of soil. Gram negative rod-shaped bacteria predominated. Decreases in the concentration of the four polycyclic aromatic hydrocarbons were observed during incubation with bacterial isolates in aqueous suspension by the use of high performance liquid chromatography. Corresponding increases in bacterial numbers indicated utilization of the compounds as a carbon source. Soil samples from the contaminated sites contained greater numbers of bacteria utilizing anthracene and pyrene than soil samples from uncontaminated sites. Degradation rates of the four polycyclic aromatic hydrocarbons were related to the compound, its concentration, and the bacterium. Biodegradation of pyrene was positively correlated with the presence of oxygen. Pyrene was biodegraded by an Acinetobacter sp. under aerobic conditions but not under anaerobic or microaerophilic conditions. Studies with radiolabeled 14 C-anthracene demonstrated utilization of the labeled carbon as a source of carbon by viable bacterial cells in aqueous suspension. Incorporation of 14 C into cellular biomass however was not observed during incubation of 14 C-anthracene in soil

  1. Big bacteria

    DEFF Research Database (Denmark)

    Schulz, HN; Jørgensen, BB


    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...

  2. Big bacteria

    DEFF Research Database (Denmark)

    Schulz, HN; Jørgensen, BB


    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...... 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 80 x 600 mum large Epulopiscium sp. from the gut of tropical fish, are presumably living in a very nutrient-rich medium. Many large bacteria contain numerous inclusions in the cells that reduce the volume of active cytoplasm. The most striking examples of competitive advantage from large cell size...

  3. Magnetic Bacteria. (United States)

    Nelson, Jane Bray; Nelson, Jim


    Describes the history of Richard Blakemore's discovery of magnetotaxic organisms. Discusses possible reasons why the magnetic response in bacteria developed. Proposes research experiments integrating biology and physics in which students investigate problems using cultures of magnetotaxic organisms. (MDH)

  4. Identification of moderately halophilic bacteria from Thai fermented fish ( pla-ra ) and proposal of Virgibacillus siamensis sp. nov. (United States)

    Tanasupawat, Somboon; Chamroensaksri, Nitcha; Kudo, Takuji; Itoh, Takashi


    Forty-one isolates of moderately halophilic bacteria were isolated from fermented fish (pla-ra) in Thailand. On the basis of their phenotypic and chemotaxonomic characteristics, DNA-DNA relatedness and 16S rRNA gene sequences analyses, they were divided into six groups. The isolates in Group I to V were Gram-positive rod-shaped bacteria. They contained meso-diaminopimelic acid in the cell-wall peptidoglycan and menaquinone with seven isoprene units (MK-7). An isolate in Group VI was a Gram-negative rod-shaped bacterium. The DNA G+C contents of tested strains ranged from 36.5-63 mol%. Ten strains (Group I) were identified as Virgibacillus dokdonensis, 13 isolates (Group II) as V. halodenitrificans, 14 isolates (Group III) as V. marismortui, 1 isolate (Group IV) as Virgibacillus sp., 2 isolates (Group V) as Bacillus vietnamnensis, and 1 isolate (Group VI) as Chromohalobacter salexigens. Isolate MS3-4 in Group IV was closely related to V. carmonensis KCTC 3819(T) (95.9%). This strain contained anteiso-C(15:0) (55.8%) and anteiso-C(17:0) (17.7%) as major cellular fatty acids and had phosphatidylglycerol, diphosphatidylglycerol and an unidentified glycolipid as polar lipids. The DNA G+C content of MS3-4 was 38.0 mol%. The strain from Group IV is proposed as Virgibacillus siamensis sp. nov. and MS3-4(T) is the type strain (JCM 15395(T) =PCU 312(T) =TISTR 1957(T)).

  5. Lactobacillus arizonensis sp. nov., isolated from jojoba meal. (United States)

    Swezey, J L; Nakamura, L K; Abbott, T P; Peterson, R E


    Five strains of simmondsin-degrading, lactic-acid-producing bacteria were isolated from fermented jojoba meal. These isolates were facultatively anaerobic, gram-positive, non-motile, non-spore-forming, homofermentative, rod-shaped organisms. They grew singly and in short chains, produced lactic acid but no gas from glucose, and did not exhibit catalase activity. Growth occurred at 15 and 45 degrees C. All strains fermented cellobiose, D-fructose, D-galactose, D-glucose, lactose, maltose, D-mannitol, D-mannose, melibiose, D-ribose, salicin, D-sorbitol, sucrose and trehalose. Some strains fermented L-(-)-arabinose and L-rhamnose. D-Xylose was not fermented and starch was not hydrolysed. The mean G+C content of the DNA was 48 mol%. Phylogenetic analyses of 16S rDNA established that the isolates were members of the genus Lactobacillus. DNA reassociation of 45% or less was obtained between the new isolates and the reference strains of species with G+C contents of about 48 mol%. The isolates were differentiated from other homofermentative Lactobacillus spp. on the basis of 16S rDNA sequence divergence, DNA relatedness, stereoisomerism of the lactic acid produced, growth temperature and carbohydrate fermentation. The data support the conclusion that these organisms represent strains of a new species, for which the name Lactobacillus arizonensis is proposed. The type strain of L. arizonensis is NRRL B-14768T (= DSM 13273T).

  6. Glucerabacter canisensis gen. nov., sp. nov., isolated from dog feces and its effect on the hydrolysis of plant glucosylceramide in the intestine of dogs. (United States)

    Kawata, Misho; Tsukamoto, Ami; Isozaki, Ryohei; Nobukawa, Shohei; Kawahara, Natsuki; Akutsu, Shoko; Suzuki, Masato; Asanuma, Narito


    A Gram-positive, obligately anaerobic, oval-rod shaped, non-spore-forming, and non-pigmented bacterium, designated strain NATH-2371 T (= JCM31739 T  = DSM105698 T ), was isolated from dog feces. Comparative 16S rRNA gene sequence analysis revealed that strain NATH-2371 T belongs to Clostridium cluster XIVa, and the closest strains were Coprococcus comes ATCC 27758 T (94.8% 16S rRNA gene sequence similarity) and Clostridium nexile DSM 1787 T (94.0%). Strain NATH-2371 T produced acetate, formate, and ethanol from glucose. Predominant cellular fatty acids are C 16:0 and C 16:0 DMA. On the basis of the phenotypic and genotypic differences, strain NATH-2371 T represents a novel species in a new genus of the family Lachnospiraceae, for which the name Glucerabacter canisensis gen. nov., sp. nov., is proposed. This strain was found to efficiently hydrolyze plant glucosylceramide (GluCer). The abundance of strain NATH-2371 T in dog feces was higher in young dogs than in old dogs. Incubation of dog fecal bacteria showed that GluCer-hydrolyzing activity decreased with the age of dogs. The cell number of strain NATH-2371 T in dog feces appeared to be correlated with GluCer hydrolysis. Thus, this bacterium is likely to play a major role in GluCer hydrolysis in the dog intestine.

  7. Identification and Pathogenicity of Phytopathogenic Bacteria Associated with Soft Rot Disease of Girasole Tuber

    Directory of Open Access Journals (Sweden)

    Mamdoh Ewis ISMAIL


    Full Text Available During 2010-2011 growing seasons six bacterial isolates were separated from naturally infected girasole plants tubers (Helianthus tuberosus L. cv. �Balady�, showing soft rot, collected from experimental Farm of the Faculty of Agriculture, in El-Minia University, Egypt. Pathogenicity tests showed various virulence for the bacteria isolated from girasole tubers, found pathogenic. These organisms were characterized as rod-shaped, Gram negative, ?-methyl-d-glucoside medium, reducing substances from sucrose, phos, phatase activity and deep cavities on pectate medium. Otherwise, diagnostic tests suggested that the pathogen was Erwinia carotovora ssp. carotovora. The isolated bacteria caused soft rot of wounded tubers when inoculated into tissues. The bacterial isolates were compared for their degree of pathogenicity as well as for differences in specific symptoms, induced in different hosts. The tested isolates could infect several host ranges, such as fruits of apricot, apple, olive, lemon, squash, eggplant and potato tubers, bulbs and garlic and onion cloves, roots radish, carrot, sweet potato and rape. On the other hand, no symptoms were exhibited on pods of bean and cowpea, faba bean, fruits of pepper and tomato. The extracts of experimentally diseased girasole tubers were active in pectinase and also in caboxymethyl cellulose at pH 6 compared to enzyme activities in healthy tissues. Also, the isolated bacteria increased the total and reducing sugars in infected tissues.

  8. Division site positioning in bacteria: one size does not fit all.

    Directory of Open Access Journals (Sweden)

    Leigh Graham Monahan


    Full Text Available Spatial regulation of cell division in bacteria has been a focus of research for decades. It has been well studied in two model rod-shaped organisms, Escherichia coli and Bacillus subtilis, with the general belief that division site positioning occurs as a result of the combination of two negative regulatory systems, Min and nucleoid occlusion. These systems influence division by preventing the cytokinetic Z ring from forming anywhere other than midcell. However, evidence is accumulating for the existence of additional mechanisms that are involved in controlling Z ring positioning both in these organisms and in several other bacteria. In some cases the decision of where to divide is solved by variations on a common evolutionary theme, and in others completely different proteins and mechanisms are involved. Here we review the different ways bacteria solve the problem of finding the right place to divide. It appears that a one-size-fits-all model does not apply, and that individual species have adapted a division-site positioning mechanism that best suits their lifestyle, environmental niche and mode of growth to ensure equal partitioning of DNA for survival of the next generation.

  9. AFM imaging of bacteria in liquid media immobilized on gelatin coated mica surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Doktycz, M.J.; Sullivan, C.J.; Hoyt, P.R.; Pelletier, D.A.; Wu, S.; Allison, D.P


    Immobilization of particulates, especially biomolecules and cells, onto surfaces is critical for imaging with the atomic force microscope (AFM). In this paper, gelatin coated mica surfaces are shown to be suitable for immobilizing and imaging both gram positive, Staphylococcus aureus, and gram negative, Escherichia coli, bacteria in both air and liquid environments. Gelatin coated surfaces are shown to be superior to poly-L-lysine coated surfaces that are commonly used for the immobilization of cells. This cell immobilization technique is being developed primarily for live cell imaging of Rhodopseudomonas palustris. The genome of R. palustris has been sequenced and the organism is the target of intensive studies aimed at understanding genome function. Images of R. palustris grown both aerobically and anaerobically in liquid media are presented. Images in liquid media show the bacteria is rod shaped and smooth while images in air show marked irregularity and folding of the surface. Significant differences in the vertical dimension are also apparent with the height of the bacteria in liquid being substantially greater than images taken in air. In air immobilized bacterial flagella are clearly seen while in liquid this structure is not visible. Additionally, significant morphological differences are observed that depend on the method of bacterial growth.

  10. Thermophilic bacteria in Moroccan hot springs, salt marshes and desert soils. (United States)

    Aanniz, Tarik; Ouadghiri, Mouna; Melloul, Marouane; Swings, Jean; Elfahime, Elmostafa; Ibijbijen, Jamal; Ismaili, Mohamed; Amar, Mohamed


    The diversity of thermophilic bacteria was investigated in four hot springs, three salt marshes and 12 desert sites in Morocco. Two hundred and forty (240) thermophilic bacteria were recovered, identified and characterized. All isolates were Gram positive, rod-shaped, spore forming and halotolerant. Based on BOXA1R-PCR and 16S rRNA gene sequencing, the recovered isolates were dominated by the genus Bacillus (97.5%) represented by B. licheniformis (119), B. aerius (44), B. sonorensis (33), B. subtilis (subsp. spizizenii (2) and subsp. inaquosurum (6)), B. amyloliquefaciens (subsp. amyloliquefaciens (4) and subsp. plantarum (4)), B. tequilensis (3), B. pumilus (3) and Bacillus sp. (19). Only six isolates (2.5%) belonged to the genus Aeribacillus represented by A. pallidus (4) and Aeribacillus sp. (2). In this study, B. aerius and B. tequilensis are described for the first time as thermophilic bacteria. Moreover, 71.25%, 50.41% and 5.41% of total strains exhibited high amylolytic, proteolytic or cellulolytic activity respectively.

  11. Thermophilic bacteria in Moroccan hot springs, salt marshes and desert soils

    Directory of Open Access Journals (Sweden)

    Tarik Aanniz


    Full Text Available The diversity of thermophilic bacteria was investigated in four hot springs, three salt marshes and 12 desert sites in Morocco. Two hundred and forty (240 thermophilic bacteria were recovered, identified and characterized. All isolates were Gram positive, rod-shaped, spore forming and halotolerant. Based on BOXA1R-PCR and 16S rRNA gene sequencing, the recovered isolates were dominated by the genus Bacillus (97.5% represented by B. licheniformis (119, B. aerius (44, B. sonorensis (33, B. subtilis (subsp. spizizenii (2 and subsp. inaquosurum (6, B. amyloliquefaciens (subsp. amyloliquefaciens (4 and subsp. plantarum (4, B. tequilensis (3, B. pumilus (3 and Bacillus sp. (19. Only six isolates (2.5% belonged to the genus Aeribacillus represented by A. pallidus (4 and Aeribacillus sp. (2. In this study, B. aerius and B. tequilensis are described for the first time as thermophilic bacteria. Moreover, 71.25%, 50.41% and 5.41% of total strains exhibited high amylolytic, proteolytic or cellulolytic activity respectively.

  12. Rumen bacteria

    International Nuclear Information System (INIS)

    McSweeney, C.S.; Denman, S.E.; Mackie, R.I.


    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 10 11 viable cells per g comprising 200 species) but a variety of ciliate protozoa occur widely (10 4 -10 6 /g distributed over 25 genera). The anaerobic fungi are also widely distributed (zoospore population densities of 10 2 -10 4 /g distributed over 5 genera). The occurrence of bacteriophage is well documented (10 7 -10 9 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

  13. Isolation and characterization of arsenic-resistant bacteria and possible application in bioremediation

    Directory of Open Access Journals (Sweden)

    Uttiya Dey


    Full Text Available Ground water arsenic contamination is a widespread problem in many developing countries including Bangladesh and India. In recent years development of modern innovative technologies for the removal of arsenic from aqueous system has become an interesting topic for research. In this present study, two rod shaped Gram-positive bacteria are being reported, isolated from arsenic affected ground water of Purbasthali block of Burdwan, West Bengal, India, which can tolerate arsenate concentration up to 4500 ppm and 550 ppm of arsenite concentration. From biochemical analysis and 16S rRNA sequencing, they were identified as Bacillus sp. and Aneurinibacillus aneurinilyticus respectively. The isolates SW2 and SW4 can remove 51.45% and 51.99% of arsenite and 53.29% and 50.37% of arsenate, respectively from arsenic containing culture media. Both of the isolate can oxidize arsenite to less toxic arsenate. These two arsenic resistant bacteria can be used as a novel pathway for the bioremediation of arsenic.

  14. Intestinal T-cell responses in celiac disease - impact of celiac disease associated bacteria.

    Directory of Open Access Journals (Sweden)

    Veronika Sjöberg

    Full Text Available A hallmark of active celiac disease (CD, an inflammatory small-bowel enteropathy caused by permanent intolerance to gluten, is cytokine production by intestinal T lymphocytes. Prerequisites for contracting CD are that the individual carries the MHC class II alleles HLA-DQ2 and/or HLA-DQ8 and is exposed to gluten in the diet. Dysbiosis in the resident microbiota has been suggested to be another risk factor for CD. In fact, rod shaped bacteria adhering to the small intestinal mucosa were frequently seen in patients with CD during the "Swedish CD epidemic" and bacterial candidates could later be isolated from patients born during the epidemic suggesting long-lasting changes in the gut microbiota. Interleukin-17A (IL-17A plays a role in both inflammation and anti-bacterial responses. In active CD IL-17A was produced by both CD8(+ T cells (Tc17 and CD4(+ T cells (Th17, with intraepithelial Tc17 cells being the dominant producers. Gluten peptides as well as CD associated bacteria induced IL-17A responses in ex vivo challenged biopsies from patients with inactive CD. The IL-17A response was suppressed in patients born during the epidemic when a mixture of CD associated bacteria was added to gluten, while the reverse was the case in patients born after the epidemic. Under these conditions Th17 cells were the dominant producers. Thus Tc17 and Th17 responses to gluten and bacteria seem to pave the way for the chronic disease with interferon-γ-production by intraepithelial Tc1 cells and lamina propria Th1 cells. The CD associated bacteria and the dysbiosis they might cause in the resident microbiota may be a risk factor for CD either by directly influencing the immune responses in the mucosa or by enhancing inflammatory responses to gluten.

  15. The Effect of Some Physical and Chemical Parameters on Regrowth of Aeromonas Bacterium and Heterotrophic Bacteria in Isfahan Drinking Water System

    Directory of Open Access Journals (Sweden)

    Sina Dobaradaran


    Full Text Available Aeromonas is one the gram – negative , non spor – formating rod shaping , facultatively anaerobic and opportunistic bactria that can cause systematic infections, leision and diarrhoea in human. Fairly high bactrial population in distribution system is not only of concern because of affecting consumer health but also it makes it difficult to enumerate coliform bacterium indicator. So, the relationships between aeromonas and heterotrophic bacteria growth with pH, temperature, turbidity, free residual cholornie and DO were determined in this study. ADA- V media was used in presumptive stage to count aeromonas bacteria for the first time in Iran on the basis of 1605 EPA (2001 method and used oxidase tests, trehalose fermentation and indol test in confirmative stage. R2A media was used to count HPC bacteria and other factors measured on the basis of standards. The results showed that positive cases of aeromonas bacteria and HPC increase in higher temperature and turbidity and lower pH. In contrast, positive cases of aeromonas bacteria and HPC decrease while free residual cholorine and DO increase. In addition,no positive case of aeromonas was observed in more than 0.2 mg/L concentration of free residual cholorine.

  16. Rheological effects of micropolar slime on the gliding motility of bacteria with slip boundary condition (United States)

    Asghar, Z.; Ali, N.; Anwar Bég, O.; Javed, T.


    Gliding bacteria are virtually everywhere. These organisms are phylogenetically diverse with their hundreds of types, different shapes and several modes of motility. One possible mode of gliding motility in the rod shaped bacteria is that they propel themselves by producing undulating waves in their body. Few bacteria glides near the solid surface over the slime without any aid of flagella so the classical Navier-Stokes equations are incapable of explaining the slime rheology at the microscopic level. Micropolar fluid dynamics however provides a solid framework for mimicking bacterial physical phenomena at both micro and nano-scales, and therefore we use the micropolar fluid to characterize the rheology of a thin layer of slime and its dominant microrotation effects. It is also assumed that there is a certain degree of slip between slime and bacterial undulating surface and also between slime and solid substrate. The flow equations are formulated under long wavelength and low Reynolds number assumptions. Exact expressions for stream function and pressure gradient are obtained. The speed of the gliding bacteria is numerically calculated by using a modified Newton-Raphson method. Slip effects and effects of non-Newtonian slime parameters on bacterial speed and power are also quantified. In addition, when the glider is fixed, the effects of slip and rheological properties of micropolar slime parameters on the velocity, micro-rotation (angular velocity) of spherical slime particles, pressure rise per wavelength, pumping and trapping phenomena are also shown graphically and discussed in detail. The study is relevant to emerging biofuel cell technologies and also bacterial biophysics.

  17. Loktanella spp. Gb03 as an algicidal bacterium, isolated from the culture of Dinoflagellate Gambierdiscus belizeanus. (United States)

    Bloh, Anmar Hameed; Usup, Gires; Ahmad, Asmat


    Bacteria associated with harmful algal blooms can play a crucial role in regulating algal blooms in the environment. This study aimed at isolating and identifying algicidal bacteria in Dinoflagellate culture and to determine the optimum growth requirement of the algicidal bacteria, Loktanella sp. Gb-03. The Dinoflagellate culture used in this study was supplied by Professor Gires Usup's Laboratory, School of Environmental and Natural Resources Sciences, Faculty of Science and Technology, University Kebangsaan Malaysia, Malaysia. The culture was used for the isolation of Loktanella sp., using biochemical tests, API 20 ONE kits. The fatty acid content of the isolates and the algicidal activity were further evaluated, and the phenotype was determined through the phylogenetic tree. Gram-negative, non-motile, non-spore-forming, short rod-shaped, aerobic bacteria (Gb01, Gb02, Gb03, Gb04, Gb05, and Gb06) were isolated from the Dinoflagellate culture. The colonies were pink in color, convex with a smooth surface and entire edge. The optimum growth temperature for the Loktanella sp. Gb03 isolate was determined to be 30°C, in 1% of NaCl and pH7. Phylogenetic analysis based on 16S rRNA gene sequences showed that the bacterium belonged to the genus Loktanella of the class Alphaproteobacteria and formed a tight cluster with the type strain of Loktanella pyoseonensis (97.0% sequence similarity). On the basis of phenotypic, phylogenetic data and genetic distinctiveness, strain Gb-03, were placed in the genus Loktanella as the type strain of species. Moreover, it has algicidal activity against seven toxic Dinoflagellate. The algicidal property of the isolated Loktanella is vital, especially where biological control is needed to mitigate algal bloom or targeted Dinoflagellates.

  18. Metabolism of sulfate-reducing bacteria and corrosion behavior of carbon steel in the continuous culturing medium; Renzoku baiyo baichichu ni okeru ryusan`en kangen no taisha to tansoko no fushoku kyodo

    Energy Technology Data Exchange (ETDEWEB)

    Baba, F.; Suzuki, T. [Ajinomoto Co. Inc., Tokyo (Japan); Seo, M. [Hokkaido University, Sapporo (Japan)


    Investigations were made on metabolism of sulfate-reducing bacteria and corrosion behavior of carbon steel in the continuous culturing medium. Sulfate-reducing bacteria were cultured for 50 days by supplying the culturing medium prepared to a prescribed chemical composition (containing Fe {sup 2+} at 0.01 mol/kg) at a rate of 10 cm {sup 3}/h, and drawing them out at the same rate. Test carbon steel pieces were immersed into this culturing medium. As a result, the following matters were clarified: the number of bacteria is maintained at more than 10 {sup 10}/cm{sup 3} after several days since inauguration of the immersion, with the bacteria stably producing H2S and FeS until the culturing is finished; comma-shaped bacteria which move actively and rod-shaped bacteria which do not move very actively exist in the culturing medium; a black film has been produced on surface of the test pieces throughout the culturing period, and satin-like corrosion was found underneath the surface; and weight increase of this film and weight decrease of the lower layer progress as the time lapses (the weight decrease of the lower layer has reached 40 mg/cm{sup 2} in 50 days). 28 refs., 8 figs., 1 tab.

  19. [Isolation and identification of seven thermophilic and anaerobic bacteria from hot springs in Tengchong Rehai]. (United States)

    Lu, Yueqing; Chen, Bo; Liu, Xiaoli; Ji, Xiuling; Wei, Yunlin; Lin, Lianbing


    In order to study the taxonomic characteristic and physiological, biochemical properties of anaerobic bacteria from hot springs in Tengchong Rehai, Yunnan Province, China. Using Hungate anaerobic technique We isolated seven strains from hot springs in Tengchong Rehai, Yunnan province, and analyzed their 16S rRNA gene sequences. The seven isolates were rod-shaped, Gram-negative, obligate anaerobe, and spores formation was not observed. All strains could grow well at 70 degrees C. Growth of strain RH0802 occurred between 60 and 80 degrees C, optimally around 70 degrees C. The pH range for its growth was between 5.5 and 8.5, with an optimum around 7.0. Strain RH0802 grew on a wide range of carbon sources, including glucose, starch, mannitol, mannose, ribose, maltose, cellobiose, xylose, fructose, galactose, xylan and glycerol, but it could not utilize sucrose or pyruvate. 16S rRNA gene phylogenetic analysis showed that the maximum similarity between the five strains and the strains of genus Caldanaerobacter was up to 98%, except RH0804 and RH0806, which reached to 96% and 93%, respectively. The two isolates were presumed to be potential novel species. The GenBank accession numbers of RH0802 to RH0808 were FJ748766, FJ748762, FJ748761, FJ748763, FJ748765, FJ748764 and FJ748767. The results showed that the seven thermophilic anaerobes belonged to the genus Caldanaerobacter.

  20. Impact of matric potential and pore size distribution on growth dynamics of filamentous and non-filamentous soil bacteria.

    Directory of Open Access Journals (Sweden)

    Alexandra B Wolf

    Full Text Available The filamentous growth form is an important strategy for soil microbes to bridge air-filled pores in unsaturated soils. In particular, fungi perform better than bacteria in soils during drought, a property that has been ascribed to the hyphal growth form of fungi. However, it is unknown if, and to what extent, filamentous bacteria may also display similar advantages over non-filamentous bacteria in soils with low hydraulic connectivity. In addition to allowing for microbial interactions and competition across connected micro-sites, water films also facilitate the motility of non-filamentous bacteria. To examine these issues, we constructed and characterized a series of quartz sand microcosms differing in matric potential and pore size distribution and, consequently, in connection of micro-habitats via water films. Our sand microcosms were used to examine the individual and competitive responses of a filamentous bacterium (Streptomyces atratus and a motile rod-shaped bacterium (Bacillus weihenstephanensis to differences in pore sizes and matric potential. The Bacillus strain had an initial advantage in all sand microcosms, which could be attributed to its faster growth rate. At later stages of the incubation, Streptomyces became dominant in microcosms with low connectivity (coarse pores and dry conditions. These data, combined with information on bacterial motility (expansion potential across a range of pore-size and moisture conditions, suggest that, like their much larger fungal counterparts, filamentous bacteria also use this growth form to facilitate growth and expansion under conditions of low hydraulic conductivity. The sand microcosm system developed and used in this study allowed for precise manipulation of hydraulic properties and pore size distribution, thereby providing a useful approach for future examinations of how these properties influence the composition, diversity and function of soil-borne microbial communities.

  1. Impact of matric potential and pore size distribution on growth dynamics of filamentous and non-filamentous soil bacteria. (United States)

    Wolf, Alexandra B; Vos, Michiel; de Boer, Wietse; Kowalchuk, George A


    The filamentous growth form is an important strategy for soil microbes to bridge air-filled pores in unsaturated soils. In particular, fungi perform better than bacteria in soils during drought, a property that has been ascribed to the hyphal growth form of fungi. However, it is unknown if, and to what extent, filamentous bacteria may also display similar advantages over non-filamentous bacteria in soils with low hydraulic connectivity. In addition to allowing for microbial interactions and competition across connected micro-sites, water films also facilitate the motility of non-filamentous bacteria. To examine these issues, we constructed and characterized a series of quartz sand microcosms differing in matric potential and pore size distribution and, consequently, in connection of micro-habitats via water films. Our sand microcosms were used to examine the individual and competitive responses of a filamentous bacterium (Streptomyces atratus) and a motile rod-shaped bacterium (Bacillus weihenstephanensis) to differences in pore sizes and matric potential. The Bacillus strain had an initial advantage in all sand microcosms, which could be attributed to its faster growth rate. At later stages of the incubation, Streptomyces became dominant in microcosms with low connectivity (coarse pores and dry conditions). These data, combined with information on bacterial motility (expansion potential) across a range of pore-size and moisture conditions, suggest that, like their much larger fungal counterparts, filamentous bacteria also use this growth form to facilitate growth and expansion under conditions of low hydraulic conductivity. The sand microcosm system developed and used in this study allowed for precise manipulation of hydraulic properties and pore size distribution, thereby providing a useful approach for future examinations of how these properties influence the composition, diversity and function of soil-borne microbial communities.

  2. Bleach vs. Bacteria (United States)

    ... 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 ...

  3. Bacteria and lignin degradation

    Institute of Scientific and Technical Information of China (English)

    Jing LI; Hongli YUAN; Jinshui YANG


    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.

  4. Spore-Forming Bacteria that Resist Sterilization (United States)

    LaDuc, Myron; Venkateswaran, Kasthuri


    A report presents a phenotypic and genotypic characterization of a bacterial species that has been found to be of the genus Bacillus and has been tentatively named B. odysseensis because it was isolated from surfaces of the Mars Odyssey spacecraft as part of continuing research on techniques for sterilizing spacecraft to prevent contamination of remote planets by terrestrial species. B. odysseensis is a Gram-positive, facultatively anaerobic, rod-shaped bacterium that forms round spores. The exosporium has been conjectured to play a role in the elevated resistance to sterilization. Research on the exosporium is proposed as a path toward improved means of sterilization, medical treatment, and prevention of biofouling.

  5. Pseudoxanthomonas koreensis sp. nov. and Pseudoxanthomonas daejeonensis sp. nov. (United States)

    Yang, Deok-Chun; Im, Wan-Taek; Kim, Myung Kyum; Lee, Sung-Taik


    Gram-negative, non-spore-forming, rod-shaped bacteria, T7-09(T) and TR6-08(T), were isolated from soil from a ginseng field in South Korea and characterized to determine their taxonomic position. 16S rRNA gene sequence analysis showed that the two isolates shared 99.5 % sequence similarity. Strains T7-09(T) and TR6-08(T) were shown to belong to the Proteobacteria and showed the highest levels of sequence similarity to Pseudoxanthomonas broegbernensis DSM 12573(T) (98.1 %), Pseudoxanthomonas mexicana AMX 26B(T) (97.4-97.5 %), Pseudoxanthomonas japonensis 12-3(T) (96.5-96.6 %), Pseudoxanthomonas taiwanensis ATCC BAA-404(T) (95.7 %) and Xanthomonas campestris ATCC 33913(T) (96.3-96.5 %). The sequence similarity values with respect to any species with validly published names in related genera were less than 96.5 %. The detection of a quinone system with Q-8 as the predominant compound and a fatty acid profile with C(15 : 0) iso as the predominant acid supported the assignment of the novel isolates to the order 'Xanthomonadales'. The two isolates could be distinguished from the established species of the genus Pseudoxanthomonas by the presence of quantitative unsaturated fatty acid C(17 : 1) iso omega9c and by their unique biochemical profiles. The results of DNA-DNA hybridization clearly demonstrated that T7-09(T) and TR6-08(T) represent separate species. On the basis of these data, it is proposed that T7-09(T) (=KCTC 12208(T)=IAM 15116(T)) and TR6-08(T) (=KCTC 12207(T)=IAM 15115(T)) be classified as the type strains of two novel Pseudoxanthomonas species, for which the names Pseudoxanthomonas koreensis sp. nov. and Pseudoxanthomonas daejeonensis sp. nov., respectively, are proposed.

  6. Genomics of Probiotic Bacteria (United States)

    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.

  7. How honey kills bacteria

    NARCIS (Netherlands)

    Kwakman, Paulus H. S.; te Velde, Anje A.; de Boer, Leonie; Speijer, Dave; Vandenbroucke-Grauls, Christina M. J. E.; Zaat, Sebastian A. J.


    With the rise in prevalence of antibiotic-resistant bacteria, honey is increasingly valued for its antibacterial activity. To characterize all bactericidal factors in a medical-grade honey, we used a novel approach of successive neutralization of individual honey bactericidal factors. All bacteria

  8. Effect of Shadowing on Survival of Bacteria under Conditions Simulating the Martian Atmosphere and UV Radiation▿ † (United States)

    Osman, Shariff; Peeters, Zan; La Duc, Myron T.; Mancinelli, Rocco; Ehrenfreund, Pascale; Venkateswaran, Kasthuri


    Spacecraft-associated spores and four non-spore-forming bacterial isolates were prepared in Atacama Desert soil suspensions and tested both in solution and in a desiccated state to elucidate the shadowing effect of soil particulates on bacterial survival under simulated Martian atmospheric and UV irradiation conditions. All non-spore-forming cells that were prepared in nutrient-depleted, 0.2-μm-filtered desert soil (DSE) microcosms and desiccated for 75 days on aluminum died, whereas cells prepared similarly in 60-μm-filtered desert soil (DS) microcosms survived such conditions. Among the bacterial cells tested, Microbacterium schleiferi and Arthrobacter sp. exhibited elevated resistance to 254-nm UV irradiation (low-pressure Hg lamp), and their survival indices were comparable to those of DS- and DSE-associated Bacillus pumilus spores. Desiccated DSE-associated spores survived exposure to full Martian UV irradiation (200 to 400 nm) for 5 min and were only slightly affected by Martian atmospheric conditions in the absence of UV irradiation. Although prolonged UV irradiation (5 min to 12 h) killed substantial portions of the spores in DSE microcosms (∼5- to 6-log reduction with Martian UV irradiation), dramatic survival of spores was apparent in DS-spore microcosms. The survival of soil-associated wild-type spores under Martian conditions could have repercussions for forward contamination of extraterrestrial environments, especially Mars. PMID:18083857

  9. Effects of Storm Events on Bacteria and Nutrients in the Bayou Chico Watershed (United States)

    Hobbs, S. E.; Truong, S.


    Levels of Escherichia coli and abiotic nutrients often increase in response to storm events due to urban runoff. The urban setting, aging septic systems, and ample pet waste (predominant sources of bacterial and nutrient contamination) that surround Bayou Chico, provide abundant possibilities for contamination. E. coli is a gram-negative, rod shaped bacteria commonly found in the intestines of animals; while some strains are harmless, others produce dangerous toxins that can cause side effects and sometimes death. Along with E. coli, inorganic nutrient concentrations (orthophosphate, nitrate/nitrite, and ammonium) are key indicators of water quality. Dissolved nutrients promote the growth of primary producers and excessive amounts lead to algal blooms, often reducing biodiversity. Four sites were sampled weekly in June and July 2017; during which, June had the highest rainfall in comparison to the past three years; these four sites represented three different sub-watersheds of the Bayou Chico Watershed, with differing land-use at each site. Historical nutrient and bacterial data from the Bream Fishermen Association was also compared and examined to determine long term trends and obtain a more in-depth understanding of the dynamics of water quality in th urban setting. E. coli levels were universally high (ranging from 98 to 12,997 MPN/100mL) for all sites and did not show observable correlations to rainfall; possibly influenced by the systemic and anomalous heavy precipitation during most of the summer study period. Nitrate was detected at levels between 2.5 and 154.0 µM, while ammonium levels ranged from 0 to 16.1 µM. Three of four stations showed extremely elevated dissolved inorganic nitrogen and ammonium while one station showed low levels of these nutrients. Correlations between these nutrient loads and rainfall, support the hypothesis that runoff into tributary creeks contributes significant inorganic nutrient loads to the Bayou Chico urban estuary.

  10. Antibiotics from predatory bacteria

    Directory of Open Access Journals (Sweden)

    Juliane Korp


    Full Text Available Bacteria, which prey on other microorganisms, are commonly found in the environment. While some of these organisms act as solitary hunters, others band together in large consortia before they attack their prey. Anecdotal reports suggest that bacteria practicing such a wolfpack strategy utilize antibiotics as predatory weapons. Consistent with this hypothesis, genome sequencing revealed that these micropredators possess impressive capacities for natural product biosynthesis. Here, we will present the results from recent chemical investigations of this bacterial group, compare the biosynthetic potential with that of non-predatory bacteria and discuss the link between predation and secondary metabolism.

  11. Massilia phosphatilytica sp. nov., a phosphate solubilizing bacteria isolated from a long-term fertilized soil

    DEFF Research Database (Denmark)

    Zheng, Bang Xiao; Bi, Qing Fang; Hao, Xiuli


    A Gram-stain-negative and rod-shaped bacterial strain, 12-OD1T, with rock phosphate solubilizing ability was isolated from agricultural soil in Hailun, Heilongjiang, PR China. The isolate was affiliated to the genus Massilia, based on 16S rRNA gene sequence alignments, having the highest similari......A Gram-stain-negative and rod-shaped bacterial strain, 12-OD1T, with rock phosphate solubilizing ability was isolated from agricultural soil in Hailun, Heilongjiang, PR China. The isolate was affiliated to the genus Massilia, based on 16S rRNA gene sequence alignments, having the highest...

  12. Extracellular communication in bacteria

    DEFF Research Database (Denmark)

    Chhabra, S.R.; Philipp, B.; Eberl, L.


    molecules, in different Gram-positive and Gram-negative bacteria they control pathogenicity, secondary metabolite production, biofilm differentiation, DNA transfer and bioluminescence. The development of biosensors for the detection of these signal molecules has greatly facilitated their subsequent chemical...

  13. Do Bacteria Age?

    Indian Academy of Sciences (India)

    Bacteria are thought to be examples of organisms that do not age. They divide by .... carry genetic material to the next generation through the process of reproduction; they are also .... molecules, and modified proteins. This report revealed that ...

  14. Social Behaviour in Bacteria

    Indian Academy of Sciences (India)


    the recipient. • Social behaviours can be categorized according to the fitness ... is actually the flagella of symbiotic spirochete bacteria that helps it to swim around .... Normal population. Responsive switching. (Environmental stress). Stochastic.

  15. [Darwin and bacteria]. (United States)

    Ledermann D, Walter


    As in 2009 the scientific world celebrates two hundreds years from the birthday of Charles Darwin and one hundred and fifty from the publication of The Origin of Species, an analysis of his complete work is performed, looking for any mention of bacteria. But it seems that the great naturahst never took knowledge about its existence, something rather improbable in a time when the discovery of bacteria shook the medical world, or he deliberately ignored them, not finding a place for such microscopic beings into his theory of evolution. But the bacteria badly affected his familiar life, killing scarlet fever one of his children and worsening to death the evolution of tuberculosis of his favourite Annie. Darwin himself could suffer the sickness of Chagas, whose etiological agent has a similar level to bacteria in the scale of evolution.

  16. Lipopolysaccharides in diazotrophic bacteria


    Serrato, Rodrigo V.


    Biological nitrogen fixation (BNF) is a process in which the atmospheric nitrogen (N2) is transformed into ammonia (NH3) by a select group of nitrogen-fixing organisms, or diazotrophic bacteria. In order to furnish the biologically useful nitrogen to plants, these bacteria must be in constant molecular communication with their host plants. Some of these molecular plant-microbe interactions are very specific, resulting in a symbiotic relationship between the diazotroph and the host. Others are...

  17. Lipopolysaccharides in diazotrophic bacteria. (United States)

    Serrato, Rodrigo V


    Biological nitrogen fixation (BNF) is a process in which the atmospheric nitrogen (N2) is transformed into ammonia (NH3) by a select group of nitrogen-fixing organisms, or diazotrophic bacteria. In order to furnish the biologically useful nitrogen to plants, these bacteria must be in constant molecular communication with their host plants. Some of these molecular plant-microbe interactions are very specific, resulting in a symbiotic relationship between the diazotroph and the host. Others are found between associative diazotrophs and plants, resulting in plant infection and colonization of internal tissues. Independent of the type of ecological interaction, glycans, and glycoconjugates produced by these bacteria play an important role in the molecular communication prior and during colonization. Even though exopolysaccharides (EPS) and lipochitooligosaccharides (LCO) produced by diazotrophic bacteria and released onto the environment have their importance in the microbe-plant interaction, it is the lipopolysaccharides (LPS), anchored on the external membrane of these bacteria, that mediates the direct contact of the diazotroph with the host cells. These molecules are extremely variable among the several species of nitrogen fixing-bacteria, and there are evidences of the mechanisms of infection being closely related to their structure.

  18. The fecal bacteria (United States)

    Sadowsky, Michael J.; Whitman, Richard L.


    The Fecal Bacteria offers a balanced, integrated discussion of fecal bacteria and their presence and ecology in the intestinal tract of mammals, in the environment, and in the food supply. This volume covers their use in examining and assessing water quality in order to offer protection from illnesses related to swimming in or ingesting contaminated water, in addition to discussing their use in engineering considerations of water quality, modeling, monitoring, and regulations. Fecal bacteria are additionally used as indicators of contamination of ready-to-eat foods and fresh produce. The intestinal environment, the microbial community structure of the gut microbiota, and the physiology and genomics of this broad group of microorganisms are explored in the book. With contributions from an internationally recognized group of experts, the book integrates medicine, public health, environmental, and microbiological topics in order to provide a unique, holistic understanding of fecal bacteria. Moreover, it shows how the latest basic science and applied research findings are helping to solve problems and develop effective management strategies. For example, readers will discover how the latest tools and molecular approaches have led to our current understanding of fecal bacteria and enabled us to improve human health and water quality. The Fecal Bacteria is recommended for microbiologists, clinicians, animal scientists, engineers, environmental scientists, food safety experts, water quality managers, and students. It will help them better understand fecal bacteria and use their knowledge to protect human and environmental health. They can also apply many of the techniques and molecular tools discussed in this book to the study of a broad range of microorganisms in a variety of habitats.

  19. Mycorrhiza helper bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Deveau, Aurelie [French National Insitute for Agricultural Research (INRA); Labbe, Jessy [ORNL


    This chapter focuses on the Mycorrhiza Helper Bacteria (MHB), a generic name given to bacteria which stimulate the formation of mycorrhizal symbiosis. By extension, some bacterial strains that positively impact the functioning of mycorrhizal symbiosis are also called MHB. These bacteria have applicative interests, as they indirectly improve the health and growth of tree seedlings. MHB are not restricted to a specific type of ecosystem, but are rather generalist in the way that they associate with both herbaceous and woody mycorrhizal plants from boreal, temperate, arid and tropical ecosystems. However, understanding the molecular mechanisms and their specificities will help us to know more about the ecology of the MHB. The process of acquisition varies between fungal species; while ectomycorrhizal fungi most probably recurrently acquire them from the environment, the association between bacterial endosymbionts and Glomeromycota probably dates back to very ancient times, and has since been vertically transmitted.

  20. Stygiolobus rod-shaped virus and the interplay of crenarchaeal rudiviruses with the CRISPR antiviral system

    DEFF Research Database (Denmark)

    Vestergaard, Gisle Alberg; Shah, Shiraz Ali; Bize, Ariane


    helicase and nuclease implicated in DNA replication. Analysis of matches between known crenarchaeal chromosomal CRISPR spacer sequences, implicated in a viral defense system, and rudiviral genomes revealed that about 10% of the 3,042 unique acidothermophile spacers yield significant matches to rudiviral...... genomes, with a bias to highly conserved protein genes, consistent with the widespread presence of rudiviruses in hot acidophilic environments. We propose that the 12-bp indels which are commonly found in conserved rudiviral protein genes may be generated as a reaction to the presence of the host CRISPR...

  1. Fabrication and field emission study of novel rod-shaped diamond-like carbon nanostructures

    International Nuclear Information System (INIS)

    Varshney, Deepak; Makarov, Vladimir I; Saxena, Puja; Weiner, Brad R; Morell, Gerardo; Gonzalez-BerrIos, Adolfo; Scott, James F


    Novel sp 3 rich diamond-like carbon nanorod films were fabricated by a hot filament chemical vapour deposition technique. The results are indicative of a bottom-up synthesis process, which results in a hierarchical structure that consists of microscale papillae comprising numerous nanorods. The papillae have diameters ranging from 2 to 4 μm and the nanorods have diameters in the 35-45 nm range. A growth mechanism based on the vapour-liquid-solid mechanism is proposed that accounts for the morphological aspects at the microscale and nanoscale. Investigation of field emission properties of fabricated nanorods reveals a low turn-on field of about 4.9 V μm -1 at 1 nA and a high field-enhancement factor.

  2. Communication among Oral Bacteria (United States)

    Kolenbrander, Paul E.; Andersen, Roxanna N.; Blehert, David S.; Egland, Paul G.; Foster, Jamie S.; Palmer, Robert J.


    Human oral bacteria interact with their environment by attaching to surfaces and establishing mixed-species communities. As each bacterial cell attaches, it forms a new surface to which other cells can adhere. Adherence and community development are spatiotemporal; such order requires communication. The discovery of soluble signals, such as autoinducer-2, that may be exchanged within multispecies communities to convey information between organisms has emerged as a new research direction. Direct-contact signals, such as adhesins and receptors, that elicit changes in gene expression after cell-cell contact and biofilm growth are also an active research area. Considering that the majority of oral bacteria are organized in dense three-dimensional biofilms on teeth, confocal microscopy and fluorescently labeled probes provide valuable approaches for investigating the architecture of these organized communities in situ. Oral biofilms are readily accessible to microbiologists and are excellent model systems for studies of microbial communication. One attractive model system is a saliva-coated flowcell with oral bacterial biofilms growing on saliva as the sole nutrient source; an intergeneric mutualism is discussed. Several oral bacterial species are amenable to genetic manipulation for molecular characterization of communication both among bacteria and between bacteria and the host. A successful search for genes critical for mixed-species community organization will be accomplished only when it is conducted with mixed-species communities. PMID:12209001


    There is a paucity of information concerning any link between the microorganisms commonly found in biofilms of drinking water systems and their impacts on human health. For bacteria, culture-based techniques detect only a limited number of the total microorganisms associated wit...

  4. Bacteria-surface interactions. (United States)

    Tuson, Hannah H; Weibel, Douglas B


    The interaction of bacteria with surfaces has important implications in a range of areas, including bioenergy, biofouling, biofilm formation, and the infection of plants and animals. Many of the interactions of bacteria with surfaces produce changes in the expression of genes that influence cell morphology and behavior, including genes essential for motility and surface attachment. Despite the attention that these phenotypes have garnered, the bacterial systems used for sensing and responding to surfaces are still not well understood. An understanding of these mechanisms will guide the development of new classes of materials that inhibit and promote cell growth, and complement studies of the physiology of bacteria in contact with surfaces. Recent studies from a range of fields in science and engineering are poised to guide future investigations in this area. This review summarizes recent studies on bacteria-surface interactions, discusses mechanisms of surface sensing and consequences of cell attachment, provides an overview of surfaces that have been used in bacterial studies, and highlights unanswered questions in this field.

  5. Antifreeze Proteins of Bacteria

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 12. Antifreeze Proteins of Bacteria. M K Chattopadhyay. General Article Volume 12 Issue 12 December 2007 pp 25-30. Fulltext. Click here to view fulltext PDF. Permanent link: ...

  6. The friendly bacteria within us Commensal bacteria of the intestine ...

    Indian Academy of Sciences (India)

    Balance of bacterial species in the gut · Immunosensory detection of intestinal bacteria · Pathogenic bacteria release interleukin-8 from HT-29 cells · Lactobacillus GG prevents the IL-8 release in response to pathogens · Effect of probiotic bacteria on chemokine response of epithelia to pathogens · PCR array studies in colon ...

  7. Spore-forming, Desulfosporosinus-like sulphate-reducing bacteria from a shallow aquifer contaminated with gasoline. (United States)

    Robertson, W J; Franzmann, P D; Mee, B J


    Previous studies on the geochemistry of a shallow unconfined aquifer contaminated with hydrocarbons suggested that the degradation of some hydrocarbons was linked to bacterial sulphate reduction. There was attenuation of naphthalene, 1,3,5-trimethylbenzene (TMB), toluene, p-xylene and ethylbenzene in the groundwater with concomitant loss of sulphate. Here, the recovery of eight strains of sulphate-reducing bacteria (SRB) from the contaminated site is reported. All were straight or curved rod-shaped cells which formed endospores. Amplification and sequencing of the 16S rDNA indicated that the strains were all sulphate reducers of the Gram-positive line of descent, and were most closely related to Desulfosporosinus (previously Desulfotomaculum) orientis DSM 8344 (97-98.9% sequence similarity). The strains clustered in three phylogenetic groups based on 16S rRNA sequences. Whole cell fatty acid compositions were similar to those of D. orientis DSM 8344, and were consistent with previous studies of fatty acids in soil and groundwater from the site. Microcosms containing groundwater from this aquifer indicated a role for sulphate reduction in the degradation of [ring-UL-14C]toluene, but not for the degradation of [UL-14C]benzene which could also be degraded by the microcosms. Adding one of the strains that was isolated from the groundwater (strain T2) to sulphate-enriched microcosms increased the rate of toluene degradation four- to 10-fold but had no effect on the rate of benzene degradation. The addition of molybdate, an inhibitor of sulphate reduction, to the groundwater samples decreased the rate of toluene mineralization. There was no evidence to support the mineralization of [UL-14C]benzene, [ring-UL-14C]toluene or unlabelled m-xylene, p-xylene, ethylbenzene, TMB or naphthalene by any of the strains in pure culture. Growth of all the strains was completely inhibited by 100 micromol l-1 TMB.

  8. Manufacture of Probiotic Bacteria (United States)

    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.

  9. Pepsin homologues in bacteria

    Directory of Open Access Journals (Sweden)

    Bateman Alex


    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

  10. Functional amyloids in bacteria. (United States)

    Romero, Diego; Kolter, Roberto


    The term amyloidosis is used to refer to a family of pathologies altering the homeostasis of human organs. Despite having a name that alludes to starch content, the amyloid accumulations are made up of proteins that polymerize as long and rigid fibers. Amyloid proteins vary widely with respect to their amino acid sequences but they share similarities in their quaternary structure; the amyloid fibers are enriched in β-sheets arranged perpendicular to the axis of the fiber. This structural feature provides great robustness, remarkable stability, and insolubility. In addition, amyloid proteins specifically stain with certain dyes such as Congo red and thioflavin-T. The aggregation into amyloid fibers, however, it is not restricted to pathogenic processes, rather it seems to be widely distributed among proteins and polypeptides. Amyloid fibers are present in insects, fungi and bacteria, and they are important in maintaining the homeostasis of the organism. Such findings have motivated the use of the term "functional amyloid" to differentiate these amyloid proteins from their toxic siblings. This review focuses on systems that have evolved in bacteria that control the expression and assembly of amyloid proteins on cell surfaces, such that the robustness of amyloid proteins are used towards a beneficial end. Copyright© by the Spanish Society for Microbiology and Institute for Catalan Studies.

  11. Cable Bacteria in Freshwater Sediments

    DEFF Research Database (Denmark)

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus


    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...... 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...

  12. Immunomodulatory properties of probiotic bacteria

    DEFF Research Database (Denmark)

    Fink, Lisbeth Nielsen


    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...... 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 intestinal microbiota...

  13. Radiation-resistant asporogenic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Yano, K [Tokyo Univ. (Japan). Faculty of Agriculture


    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.

  14. Radiation-resistant asporogenic bacteria

    International Nuclear Information System (INIS)

    Yano, Keiji


    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.)

  15. Acoustofluidic bacteria separation

    International Nuclear Information System (INIS)

    Li, Sixing; Huang, Tony Jun; Ma, Fen; Zeng, Xiangqun; Bachman, Hunter; Cameron, Craig E


    Bacterial separation from human blood samples can help with the identification of pathogenic bacteria for sepsis diagnosis. In this work, we report an acoustofluidic device for label-free bacterial separation from human blood samples. In particular, we exploit the acoustic radiation force generated from a tilted-angle standing surface acoustic wave (taSSAW) field to separate Escherichia coli from human blood cells based on their size difference. Flow cytometry analysis of the E. coli separated from red blood cells shows a purity of more than 96%. Moreover, the label-free electrochemical detection of the separated E. coli displays reduced non-specific signals due to the removal of blood cells. Our acoustofluidic bacterial separation platform has advantages such as label-free separation, high biocompatibility, flexibility, low cost, miniaturization, automation, and ease of in-line integration. The platform can be incorporated with an on-chip sensor to realize a point-of-care sepsis diagnostic device. (paper)

  16. Acoustofluidic bacteria separation (United States)

    Li, Sixing; Ma, Fen; Bachman, Hunter; Cameron, Craig E.; Zeng, Xiangqun; Huang, Tony Jun


    Bacterial separation from human blood samples can help with the identification of pathogenic bacteria for sepsis diagnosis. In this work, we report an acoustofluidic device for label-free bacterial separation from human blood samples. In particular, we exploit the acoustic radiation force generated from a tilted-angle standing surface acoustic wave (taSSAW) field to separate Escherichia coli from human blood cells based on their size difference. Flow cytometry analysis of the E. coli separated from red blood cells shows a purity of more than 96%. Moreover, the label-free electrochemical detection of the separated E. coli displays reduced non-specific signals due to the removal of blood cells. Our acoustofluidic bacterial separation platform has advantages such as label-free separation, high biocompatibility, flexibility, low cost, miniaturization, automation, and ease of in-line integration. The platform can be incorporated with an on-chip sensor to realize a point-of-care sepsis diagnostic device.

  17. Bacteria, phages and septicemia.

    Directory of Open Access Journals (Sweden)

    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.

  18. Ecophysiology of the Anammox Bacteria

    NARCIS (Netherlands)

    Kartal, M.B.


    Anaerobic ammonium oxidizing (anammox) bacteria oxidize ammonium to dinitrogen gas with nitrite as the electron acceptor. These bacteria are the key players in the global nitrogen cycle, responsible for the most of nitrogen production in natural ecosystems. The anammox process is also a

  19. Money and transmission of bacteria.

    NARCIS (Netherlands)

    Gedik, H.; Voss, T.A.; Voss, A.


    Money is one of the most frequently passed items in the world. The aim of this study was to ascertain the survival status of bacteria including Staphylococcus aureus, Escherichia coli, and Vancomycin- Resistant Enterococci (VRE) on banknotes from different countries and the transmission of bacteria

  20. Motility of electric cable bacteria

    DEFF Research Database (Denmark)

    Bjerg, Jesper Tataru; Damgaard, Lars Riis; Holm, Simon Agner


    Cable bacteria are filamentous bacteria that electrically couple sulfide oxidation and oxygen reduction at centimeter distances, and observations in sediment environments have suggested that they are motile. By time-lapse microscopy, we found that cable bacteria used gliding motility on surfaces...... with a highly variable speed of 0.50.3 ms1 (meanstandard deviation) and time between reversals of 155108 s. They frequently moved forward in loops, and formation of twisted loops revealed helical rotation of the filaments. Cable bacteria responded to chemical gradients in their environment, and around the oxic......-anoxic interface, they curled and piled up, with straight parts connecting back to the source of sulfide. Thus, it appears that motility serves the cable bacteria in establishing and keeping optimal connections between their distant electron donor and acceptors in a dynamic sediment environment....


    NARCIS (Netherlands)

    Van Grinsven Bart Robert, Nicolaas; Cleij, Thomas


    A method for characterizing bacteria includes passing a liquid containing an analyte comprising a first bacteria and a second bacteria over and in contact with a polymer material on a substrate. The polymer material is formulated to bind to the first bacteria, and the first bacteria binds to the

  2. Isolation and characterization of two new homoacetogenic hydrogen-utilizing bacteria from the human intestinal tract that are closely related to Clostridium coccoides. (United States)

    Kamlage, B; Gruhl, B; Blaut, M


    Two gram-positive, strictly anoxic, coccoid- to rod-shaped strains of bacteria, Clostridium coccoides 1410 and C. coccoides 3110, were isolated from human feces on the typical homoacetogenic substrates formate plus H2 plus CO2 (strain 1410) and vanillate plus H2 plus CO2 (strain 3110) in the presence of 2-bromoethanesulfonate to inhibit methanogenesis. On the basis of 16S rRNA sequencing, DNA-DNA hybridization, and physiological and morphological parameters, both isolates are closely related to C. coccoides DSM 935T. The G+C contents of the DNA were 46.1 and 46.2 mol% for C. coccoides 1410 and C. coccoides 3110, respectively. Cytochromes could not be detected. Formate was degraded exclusively to acetate, whereas vanillate was O-demethylated, resulting in acetate and 3,4-dihydroxybenzoate, the latter being further decarboxylated to catechol. In the presence of organic substrates, H2 was cometabolized to acetate, but both strains failed to grow autotrophically. Lactose, lactulose, sorbitol, glucose, and various other carbohydrates supported growth as well. Untypical of homoacetogens, glucose and sorbitol were fermented not exclusively to acetate; instead, considerable amounts of succinate and D-lactate were produced. H2 was evolved from carbohydrates only in negligible traces. Acetogenesis from formate plus H2 plus CO2 or vanillate plus H2 plus CO2 was constitutive, whereas utilization of carbohydrates was inducible. Hydrogenase, CO dehydrogenase, formate dehydrogenase, and all of the tetrahydrofolic acid-dependent, C1 compound-converting enzymes of the acetyl-coenzyme A pathway of homoacetogenesis were present in cell extracts.

  3. Review on SERS of Bacteria

    Directory of Open Access Journals (Sweden)

    Pamela A. Mosier-Boss


    Full Text Available Surface enhanced Raman spectroscopy (SERS has been widely used for chemical detection. Moreover, the inherent richness of the spectral data has made SERS attractive for use in detecting biological materials, including bacteria. This review discusses methods that have been used to obtain SERS spectra of bacteria. The kinds of SERS substrates employed to obtain SERS spectra are discussed as well as how bacteria interact with silver and gold nanoparticles. The roll of capping agents on Ag/Au NPs in obtaining SERS spectra is examined as well as the interpretation of the spectral data.

  4. Beer spoilage bacteria and hop resistance

    NARCIS (Netherlands)

    Sakamoto, K; Konings, WN


    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

  5. Electron transport chains of lactic acid bacteria

    NARCIS (Netherlands)

    Brooijmans, R.J.W.


    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

  6. Gut Bacteria Affect Immunotherapy Response (United States)

    Three new studies have identified intestinal bacteria that appear to influence the response to checkpoint inhibitors. This Cancer Currents blog post explains how the researchers think their findings could be used to improve patients’ responses to these immunotherapy drugs.

  7. hydroxyalkanoate (PHAs) producing bacteria isolated

    African Journals Online (AJOL)



    Jul 4, 2007 ... ium (MSM), having inhibitors for Gram positive bacteria and fungi and a mixed ... Two techniques were used for detecting the presence of polymer: staining ... was saline solution at 600 nm wavelength on VARIAN DSM 100.

  8. Thymidine kinase diversity in bacteria

    DEFF Research Database (Denmark)

    Sandrini, Michael; Clausen, A.R.; Munch-Petersen, B.


    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....... The TKs from Gram-positive bacteria are more closely related to the eukaryotic TK1 enzymes than are TKs from Gram-negative bacteria....

  9. Anaerobic bacteria that dechlorinate perchloroethene. (United States)

    Fathepure, B Z; Nengu, J P; Boyd, S A


    In this study, we identified specific cultures of anaerobic bacteria that dechlorinate perchlorethene (PCE). The bacteria that significantly dechlorinated PCE were strain DCB-1, an obligate anaerobe previously shown to dechlorinate chlorobenzoate, and two strains of Methanosarcina. The rate of PCE dechlorination by DCB-1 compared favorably with reported rates of trichloroethene bio-oxidation by methanotrophs. Even higher PCE dechlorination rates were achieved when DCB-1 was grown in a methanogenic consortium. PMID:3426224

  10. Simplicispira soli sp. nov., a betaproteobacterium isolated from stream bank soil. (United States)

    Dahal, Ram Hari; Kim, Jaisoo


    Two strains of soil bacteria, designated CA-16 T and CA-161, were isolated from a sample of stream bank soil near Kyonggi University. Cells were strictly aerobic, Gram-stain-negative, catalase-negative, oxidase-positive, motile, non-spore-forming and rod-shaped. Colonies on tryptone soya agar were brownish cream in colour. Tyrosine, Tween 60 and Tween 40 were hydrolysed. The indole test was positive. Malic acid, lactic acid and valeric acid were assimilated. Phylogenetic analysis based on their 16S rRNA gene sequences revealed that strains CA-16 T and CA-161 formed a lineage within the family Comamonadaceae of the class Betaproteobacteria that were distinct from various species of the genus Simplicispira. Strain CA-16 T was most closely related to Simplicispira metamorpha DSM 1837 T (97.86 % sequence similarity), Simplicispira limi EMB325 T (97.72 %), Simplicispira psychrophila DSM 11588 T (96.83 %) and Simplicispira piscis RSG39 T (96.71 %). Both strains contained Q-8 as the major isoprenoid quinone. The major polar lipids of the strains were phosphatidylglycerol, phosphatidylethanolamine and diphosphatidylglycerol. The major cellular fatty acids were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C18 : 1ω7c-11methyl, C16 : 0, summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C12 : 0. The DNA G+C contents of the strains were 63.9-64.4 mol%. DNA-DNA hybridization similarities between strain CA-16 T and other closest members of the genus Simplicispira ranged from 16 % to 24 %. On the basis of phenotypic, genotypic, chemotaxonomic and phylogenetic analyses, strains CA-16 T and CA-161 represent a single novel species of the genus Simplicispira, for which the name Simplicispirasoli sp. nov. is proposed. The type strain is CA-16 T (=KEMB 9005-529 T =KACC 19107 T =NBRC 112689 T ).

  11. Lysobacter oligotrophicus sp. nov., isolated from an Antarctic freshwater lake in Antarctica. (United States)

    Fukuda, Wakao; Kimura, Tomomi; Araki, Shigeo; Miyoshi, Yuki; Atomi, Haruyuki; Imanaka, Tadayuki


    A Gram-stain-negative, non-spore-forming, rod-shaped, aerobic bacterium (strain 107-E2(T)) was isolated from freshwater samples containing microbial mats collected at a lake in Skarvsnes, Antarctica (temporary lake name, Lake Tanago Ike). Strain 107-E2(T) grew between 5 and 25 °C, with an optimum of 23 °C. Moreover, colony formation was observed on agar media even at -5 °C. The pH range for growth was between 6.0 and 9.0, with an optimum of pH 7.0-8.0. The range of NaCl concentration for growth was between 0.0 and 0.5% (w/v), with an optimum of 0.0%. No growth was observed in media containing organic compounds at high concentrations, which indicated that strain 107-E2(T) was an oligotroph. In the late stationary phase, strain 107-E2(T) produced a dark brown water-soluble pigment. Esterase, amylase and protease production was observed. Antimicrobial-lytic activities for Gram-negative bacteria and yeast were observed. Ubiquinone-8 was the major respiratory quinone. The major fatty acids were iso-C15:0, iso-C(17:1)ω9c and iso-C(15:1) at 5. The G+C content of genomic DNA was 66.1 mol%. Analysis of the 16S rRNA gene sequences revealed that strain 107-E2(T) belonged to the genus Lysobacter, and low DNA-DNA relatedness values with closely related species distinguished strain 107-E2(T) from recognized species of the genus Lysobacter. The phylogenetic situation and physiological characteristics indicated that strain 107-E2(T) should be classified as a representative of a novel species of the genus Lysobacter, for which the name Lysobacter oligotrophicus sp. nov. is proposed. The type strain is 107-E2(T) ( =JCM 18257(T) =ATCC BAA-2438(T)).

  12. Demequina lutea sp. nov., isolated from a high Arctic permafrost soil. (United States)

    Finster, Kai Waldemar; Herbert, Rodney Andrew; Kjeldsen, Kasper Urup; Schumann, Peter; Lomstein, Bente Aagaard


    Two Gram-stain-positive, pigmented, non-motile, non-spore-forming, pleomorphic, rod-shaped bacteria (strains SV45(T) and SV47), isolated from a permafrost soil collected from the Adventdalen valley, Spitsbergen, northern Norway, have been characterized taxonomically using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the two permafrost isolates formed a distinct phyletic line within the suborder Micrococcineae of the order Actinomycetales. DNA-DNA hybridization analyses indicate that strains SV45(T) and SV47 are closely related (60-69 % relatedness) and belong to the same species, although they show slightly different colony pigmentation. The closest phylogenetic neighbour was Demequina aestuarii JC2054(T), with 96 % 16S rRNA gene sequence similarity. Optimum growth of SV45(T) and SV47 occurred aerobically in the absence of NaCl, but both isolates tolerated up to 2 % NaCl (w/v) in the growth medium. Growth under anaerobic conditions was slow and weak. The peptidoglycan of both isolates was of the A4beta type with l-ornithine as the diamino acid and serine as a component of the interpeptide bridge with either d-aspartate (SV45(T)) or d-glutamate (SV47) as the N-terminal amino acid. The major fatty acids present in both isolates were C(15 : 0) (3.2-8.6 %), iso-C(16 : 0) (5.0-8.9 %), anteiso-C(15 : 0) (59.4-61.5 %), anteiso-C(17 : 0) (4.1-8.8 %) and anteiso-C(15 : 1) (4.4-6.4 %). Isoprenoid quinones were present at exceptionally low levels in both isolates, and only demethylmenaquinone DMK-9(H(4)) could be identified with any degree of confidence. Phylogenetic analysis and differences in physiological and biochemical characteristics between the strains and Demequina aestuarii JC2054(T) indicate that these isolates belong to a novel species within the genus Demequina, for which the name Demequina lutea sp. nov. is proposed. The type strain is SV45(T) (=LMG 24795(T) =DSM 19970(T)).

  13. Olsenella umbonata sp. nov., a microaerotolerant anaerobic lactic acid bacterium from the sheep rumen and pig jejunum, and emended descriptions of Olsenella, Olsenella uli and Olsenella profusa. (United States)

    Kraatz, Mareike; Wallace, R John; Svensson, Liselott


    Strain A2 is an anaerobic, variably Gram-stain-positive, non-spore-forming, small and irregularly rod-shaped bacterium from the ruminal fluid of a sheep that has been described informally as a representative of 'Olsenella (basonym Atopobium) oviles'. Three phenotypically similar bacterial strains (lac15, lac16 and lac31(T)) were isolated in concert with Veillonella magna lac18(T) from the mucosal jejunum of a pig. A phylogenetic analysis based on 16S rRNA gene sequences revealed that strains A2, lac15, lac16 and lac31(T) formed a genetically coherent group (100 % interstrain sequence similarity) within the bigeneric Olsenella-Atopobium branch of the family Coriobacteriaceae, class Actinobacteria. This group was most closely related to the type strains of the two recognized Olsenella species, namely Olsenella uli (sequence similarity of 96.85 %) and Olsenella profusa (sequence similarity of 97.20 %). The sequence similarity to the type strain of Atopobium minutum, the type species of the genus Atopobium, was 92.33 %. Unlike those of O. uli and O. profusa, outgrown colonies of strains A2, lac15, lac16 and lac31(T) were opaque and greyish-white with an umbonate elevation on solid culture media. The four novel strains were characterized as being well-adapted and presumably indigenous to the gastrointestinal tract of homoeothermic vertebrates: they were mesophilic, microaerotolerant, neutrophilic and acidotolerant, bile-resistant, mucin-utilizing and markedly peptidolytic lactic acid bacteria. The results of DNA-DNA hybridizations, cellular fatty acid analysis and other differential phenotypic (physiological and biochemical) tests confirmed that strains A2, lac15, lac16 and lac31(T) represent a novel species of the genus Olsenella. On the basis of the genotypic and phenotypic results, we therefore describe Olsenella umbonata sp. nov., with lac31(T) ( = CCUG 58604(T)  = DSM 22620(T)  = JCM 16156(T)) as the type strain and A2 ( = CCUG 58212

  14. Human body may produce bacteria. (United States)

    Salerian, Alen J


    "Human body may produce bacteria" proposes that human body may produce bacteria and represent an independent source of infections contrary to the current paradigm of infectious disorders proposed by Louis Pasteur in 1880. The following observations are consistent with this hypothesis: A. Bidirectional transformations of both living and nonliving things have been commonly observed in nature. B. Complex multicellular organisms harbor the necessary properties to produce bacteria (water, nitrogen and oxygen). C. Physical laws suggest any previously observed phenomenon or action will occur again (life began on earth; a non living thing). D. Animal muscle cells may generate energy (fermentation). E. Sterilized food products (i.e. boiled eggs), may produce bacteria and fungus under special conditions and without any exposure to foreign living cells. "Human body may produce bacteria" may challenge the current medical paradigm that views human infectious disorders as the exclusive causative byproducts of invading foreign cells. It may also introduce new avenues to treat infectious disorders. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Horizontal gene transfer between bacteria. (United States)

    Heuer, Holger; Smalla, Kornelia


    Horizontal gene transfer (HGT) refers to the acquisition of foreign genes by organisms. The occurrence of HGT among bacteria in the environment is assumed to have implications in the risk assessment of genetically modified bacteria which are released into the environment. First, introduced genetic sequences from a genetically modified bacterium could be transferred to indigenous micro-organisms and alter their genome and subsequently their ecological niche. Second, the genetically modified bacterium released into the environment might capture mobile genetic elements (MGE) from indigenous micro-organisms which could extend its ecological potential. Thus, for a risk assessment it is important to understand the extent of HGT and genome plasticity of bacteria in the environment. This review summarizes the present state of knowledge on HGT between bacteria as a crucial mechanism contributing to bacterial adaptability and diversity. In view of the use of GM crops and microbes in agricultural settings, in this mini-review we focus particularly on the presence and role of MGE in soil and plant-associated bacteria and the factors affecting gene transfer.

  16. Chitin Degradation In Marine Bacteria

    DEFF Research Database (Denmark)

    Paulsen, Sara; Machado, Henrique; Gram, Lone


    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....

  17. Methylotrophic bacteria in sustainable agriculture. (United States)

    Kumar, Manish; Tomar, Rajesh Singh; Lade, Harshad; Paul, Diby


    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.

  18. Phylogenetic Diversity, Distribution, and Cophylogeny of Giant Bacteria (Epulopiscium) with their Surgeonfish Hosts in the Red Sea (United States)

    Miyake, Sou; Ngugi, David K.; Stingl, Ulrich


    Epulopiscium is a group of giant bacteria found in high abundance in intestinal tracts of herbivorous surgeonfish. Despite their peculiarly large cell size (can be up to 600 μm), extreme polyploidy (some with over 100,000 genome copies per cell) and viviparity (whereby mother cells produce live offspring), details about their diversity, distribution or their role in the host gut are lacking. Previous studies have highlighted the existence of morphologically distinct Epulopiscium cell types (defined as morphotypes A to J) in some surgeonfish genera, but the corresponding genetic diversity and distribution among other surgeonfishes remain mostly unknown. Therefore, we investigated the phylogenetic diversity of Epulopiscium, distribution and co-occurrence in multiple hosts. Here, we identified eleven new phylogenetic clades, six of which were also morphologically characterized. Three of these novel clades were phylogenetically and morphologically similar to cigar-shaped type A1 cells, found in a wide range of surgeonfishes including Acanthurus nigrofuscus, while three were similar to smaller, rod-shaped type E that has not been phylogenetically classified thus far. Our results also confirmed that biogeography appears to have relatively little influence on Epulopiscium diversity, as clades found in the Great Barrier Reef and Hawaii were also recovered from the Red Sea. Although multiple symbiont clades inhabited a given species of host surgeonfish and multiple host species possessed a given symbiont clade, statistical analysis of host and symbiont phylogenies indicated significant cophylogeny, which in turn suggests co-evolutionary relationships. A cluster analysis of Epulopiscium sequences from previously published amplicon sequencing dataset revealed a similar pattern, where specific clades were consistently found in high abundance amongst closely related surgeonfishes. Differences in abundance may indicate specialization of clades to certain gut environments

  19. Phylogenetic Diversity, Distribution, and Cophylogeny of Giant Bacteria (Epulopiscium) with their Surgeonfish Hosts in the Red Sea

    KAUST Repository

    Miyake, Sou


    Epulopiscium is a group of giant bacteria found in high abundance in intestinal tracts of herbivorous surgeonfish. Despite their peculiarly large cell size (can be up to 600 μm), extreme polyploidy (some with over 100,000 genome copies per cell) and viviparity (whereby mother cells produce live offspring), details about their diversity, distribution or their role in the host gut are lacking. Previous studies have highlighted the existence of morphologically distinct Epulopiscium cell types (defined as morphotypes A to J) in some surgeonfish genera, but the corresponding genetic diversity and distribution among other surgeonfishes remain mostly unknown. Therefore, we investigated the phylogenetic diversity of Epulopiscium, distribution and co-occurrence in multiple hosts. Here, we identified eleven new phylogenetic clades, six of which were also morphologically characterized. Three of these novel clades were phylogenetically and morphologically similar to cigar-shaped type A1 cells, found in a wide range of surgeonfishes including Acanthurus nigrofuscus, while three were similar to smaller, rod-shaped type E that has not been phylogenetically classified thus far. Our results also confirmed that biogeography appears to have relatively little influence on Epulopiscium diversity, as clades found in the Great Barrier Reef and Hawaii were also recovered from the Red Sea. Although multiple symbiont clades inhabited a given species of host surgeonfish and multiple host species possessed a given symbiont clade, statistical analysis of host and symbiont phylogenies indicated significant cophylogeny, which in turn suggests co-evolutionary relationships. A cluster analysis of Epulopiscium sequences from previously published amplicon sequencing dataset revealed a similar pattern, where specific clades were consistently found in high abundance amongst closely related surgeonfishes. Differences in abundance may indicate specialization of clades to certain gut environments

  20. Phylogenetic Diversity, Distribution, and Cophylogeny of Giant Bacteria (Epulopiscium) with their Surgeonfish Hosts in the Red Sea

    KAUST Repository

    Miyake, Sou; Ngugi, David; Stingl, Ulrich


    Epulopiscium is a group of giant bacteria found in high abundance in intestinal tracts of herbivorous surgeonfish. Despite their peculiarly large cell size (can be up to 600 μm), extreme polyploidy (some with over 100,000 genome copies per cell) and viviparity (whereby mother cells produce live offspring), details about their diversity, distribution or their role in the host gut are lacking. Previous studies have highlighted the existence of morphologically distinct Epulopiscium cell types (defined as morphotypes A to J) in some surgeonfish genera, but the corresponding genetic diversity and distribution among other surgeonfishes remain mostly unknown. Therefore, we investigated the phylogenetic diversity of Epulopiscium, distribution and co-occurrence in multiple hosts. Here, we identified eleven new phylogenetic clades, six of which were also morphologically characterized. Three of these novel clades were phylogenetically and morphologically similar to cigar-shaped type A1 cells, found in a wide range of surgeonfishes including Acanthurus nigrofuscus, while three were similar to smaller, rod-shaped type E that has not been phylogenetically classified thus far. Our results also confirmed that biogeography appears to have relatively little influence on Epulopiscium diversity, as clades found in the Great Barrier Reef and Hawaii were also recovered from the Red Sea. Although multiple symbiont clades inhabited a given species of host surgeonfish and multiple host species possessed a given symbiont clade, statistical analysis of host and symbiont phylogenies indicated significant cophylogeny, which in turn suggests co-evolutionary relationships. A cluster analysis of Epulopiscium sequences from previously published amplicon sequencing dataset revealed a similar pattern, where specific clades were consistently found in high abundance amongst closely related surgeonfishes. Differences in abundance may indicate specialization of clades to certain gut environments


    DEFF Research Database (Denmark)

    Volpi, Marta


    solely based on endospores of sulphate-reducing bacteria (SRB), which presumably constitute only a small fraction of the total thermophilic endospore community reaching cold environments. My PhD project developed an experimental framework for using thermophilic fermentative endospores (TFEs) to trace...

  2. Alternative sources of Legionella bacteria

    NARCIS (Netherlands)

    van Heijnsbergen, H.H.L.


    Legionella bacteria can cause Legionnaires’ disease (LD) in humans. Symptoms of LD can range from mild disease to severe pneumonia with sometimes fatal outcome. In the Netherlands, the most important infective agent is Legionella pneumophila. L. pneumophila infection is associated with aquatic

  3. Programmed survival of soil bacteria

    DEFF Research Database (Denmark)

    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...

  4. Automated radiometric detection of bacteria

    International Nuclear Information System (INIS)

    Waters, J.R.


    A new radiometric method called BACTEC, used for the detection of bacteria in cultures or in supposedly sterile samples, was discussed from the standpoint of methodology, both automated and semi-automated. Some of the results obtained so far were reported and some future applications and development possibilities were described. In this new method, the test sample is incubated in a sealed vial with a liquid culture medium containing a 14 C-labeled substrate. If bacteria are present, they break down the substrate, producing 14 CO 2 which is periodically extracted from the vial as a gas and is tested for radioactivity. If this gaseous radioactivity exceeds a threshold level, it is evidence of bacterial presence and growth in the test vial. The first application was for the detection of bacteria in the blood cultures of hospital patients. Data were presented showing typical results. Also discussed were future applications, such as rapid screening for bacteria in urine industrial sterility testing and the disposal of used 14 C substrates. (Mukohata, S.)

  5. Synthetic Biology in Streptomyces Bacteria

    NARCIS (Netherlands)

    Medema, Marnix H.; Breitling, Rainer; Takano, Eriko


    Actinomycete bacteria of the genus Streptomyces are major producers of bioactive compounds for the biotechnology industry. They are the source of most clinically used antibiotics, as well as of several widely used drugs against common diseases, including cancer . Genome sequencing has revealed that

  6. Deodorant bacteria; Des bacteries desodorisantes

    Energy Technology Data Exchange (ETDEWEB)

    Fanlo, J.L. [Ecole Nationale Superieure des Mines, 30 - Ales (France)


    Purifying bacteria: if this concept is not new, its application to gases cleansing has only been developed recently. This method allows to eliminate the volatile organic compounds and the gaseous effluents odors which come from industrial sites. Three bioreactors types exist at the present time. Their principles are explained. (O.M.) 6 refs.

  7. Fuzzy species among recombinogenic bacteria

    Directory of Open Access Journals (Sweden)

    Fraser Christophe


    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.

  8. High-Level Systemic Expression of Conserved Influenza Epitope in Plants on the Surface of Rod-Shaped Chimeric Particles

    Directory of Open Access Journals (Sweden)

    Natalia V. Petukhova


    Full Text Available Recombinant viruses based on the cDNA copy of the tobacco mosaic virus (TMV genome carrying different versions of the conserved M2e epitope from influenza virus A cloned into the coat protein (CP gene were obtained and partially characterized by our group previously; cysteines in the human consensus M2e sequence were changed to serine residues. This work intends to show some biological properties of these viruses following plant infections. Agroinfiltration experiments on Nicotiana benthamiana confirmed the efficient systemic expression of M2e peptides, and two point amino acid substitutions in recombinant CPs significantly influenced the symptoms and development of viral infections. Joint expression of RNA interference suppressor protein p19 from tomato bushy stunt virus (TBSV did not affect the accumulation of CP-M2e-ser recombinant protein in non-inoculated leaves. RT-PCR analysis of RNA isolated from either infected leaves or purified TMV-M2e particles proved the genetic stability of TMV‑based viral vectors. Immunoelectron microscopy of crude plant extracts demonstrated that foreign epitopes are located on the surface of chimeric virions. The rod‑shaped geometry of plant-produced M2e epitopes is different from the icosahedral or helical filamentous arrangement of M2e antigens on the carrier virus-like particles (VLP described earlier. Thereby, we created a simple and efficient system that employs agrobacteria and plant viral vectors in order to produce a candidate broad-spectrum flu vaccine.

  9. Numerical study on the matching law between charge caliber and delay time of the rod-shaped explosively formed projectile (United States)

    Shen, H. M.; Li, W. B.; Wang, X. M.; Li, W. B.


    To study the application of multi-point initiation technology on shaped charge warhead, numerically simulated the influence of initiating delay time of different charge caliber on detonation wave and performance forming of penetrator. The study found that as charge caliber increased, the allowable initiating delay time also increased. For the commonly used small and medium-charge caliber shaped charge warhead, the charge caliber(Dk ) and the delay time (σ) presented a linear relationship σ = -12.79+1.25Dk . As charge caliber continue increasing, the initiating allowable delay time started to increase exponentially. The study reveals the matching law between charge caliber, initiating delay time and performance forming of penetrator, and it offers guidance for the design of multi-point initiation network for shaped charge.

  10. Genetics of Lactic Acid Bacteria (United States)

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

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

  11. Re-engineering bacteria for ethanol production (United States)

    Yomano, Lorraine P; York, Sean W; Zhou, Shengde; Shanmugam, Keelnatham; Ingram, Lonnie O


    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.

  12. Oligotrophic bacteria isolated from clinical materials.


    Tada, Y; Ihmori, M; Yamaguchi, J


    Oligotrophic bacteria (oligotrophs) are microorganisms that grow in extremely nutritionally deficient conditions in which the concentrations of organic substances are low. Many oligotrophic bacteria were isolated from clinical materials including urine, sputum, swabbings of the throat, vaginal discharges, and others. Seventy-seven strains of oligotrophic bacteria from 871 samples of clinical material were isolated. A relatively higher frequency of isolation of oligotrophic bacteria was shown ...

  13. Geobiology of Marine Magnetotactic Bacteria (United States)


    prokaryotic cells of diverse phylogeny when grown in media containing 45 1mM iron, suggesting some kind of detoxification function . The inclusions were...salt marsh productivity. FISH also showed that aggregates consist of genetically identical cells. QPCR data indicated that populations are advisor Katrina Edwards for taking a chance on someone who initially knew nothing about magnetotactic bacteria, microbial ecology , or microbiology

  14. Nitrogen-fixing methane-utilizing bacteria

    NARCIS (Netherlands)

    Bont, de J.A.M.


    Methane occurs abundantly in nature. In the presence of oxygen this gas may be metabolized by bacteria that are able to use it as carbon and energy source. Several types of bacteria involved in the oxidation of methane have been described in literature. Methane-utilizing bacteria have in

  15. Laser-Based Identification of Pathogenic Bacteria (United States)

    Rehse, Steven J.


    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…

  16. Current strategies for improving food bacteria

    NARCIS (Netherlands)

    Kuipers, O P; Buist, Girbe; Kok, Jan


    Novel concepts and methodologies are emerging that hold great promise for the directed improvement of food-related bacteria, specifically lactic acid bacteria. Also, the battle against food spoilage and pathogenic bacteria can now be fought more effectively. Here we describe recent advances in

  17. Ecology of mycophagous collimonas bacteria in soil

    NARCIS (Netherlands)

    Höppener-Ogawa, Sachie


    Bacteria belonging to the genus Collimonas consist of soil bacteria that can grow at expense of living fungal hyphae i.e. they are mycophagous. This PhD studies deals with the ecology of mycophagous bacteria in soil using collimonads as model organisms. Collimonads were found to be widely

  18. AIDS: "it's the bacteria, stupid!". (United States)

    Broxmeyer, Lawrence; Cantwell, Alan


    Acid-fast tuberculous mycobacterial infections are common in AIDS and are regarded as secondary "opportunistic infections." According to the National Institute of Allergy and Infectious Diseases, TB is the major attributable cause of death in AIDS patients. Could such bacteria play a primary or causative role in AIDS? Certainly, In screening tests for HIV, there is frequent, up to 70%, cross-reactivity, between the gag and pol proteins of HIV and patients with mycobacterial infections such as tuberculosis. By 1972, five years before gays started dying in the U.S., Rolland wrote Genital Tuberculosis, a Forgotten Disease? And ironically, in 1979, on the eve of AIDS recognition, Gondzik and Jasiewicz showed that even in the laboratory, genitally infected tubercular male guinea pigs could infect healthy females through their semen by an HIV-compatible ratio of 1 in 6 or 17%, prompting him to warn his patients that not only was tuberculosis a sexually transmitted disease, but also the necessity of the application of suitable contraceptives, such as condoms, to avoid it. Gondzik's solution and date of publication are chilling; his findings significant. Since 1982 Cantwell et al found acid-fast bacteria closely related to tuberculosis (TB) and atypical tuberculosis in AIDS tissue. On the other hand molecular biologist and virologist Duesberg, who originally defined retroviral ultrastructure, has made it clear that HIV is not the cause of AIDS and that the so-called AIDS retrovirus has never been isolated in its pure state. Dr. Etienne de Harven, first to examine retroviruses under the electron, agrees. In 1993 HIV co-discoverer Luc Montagnier reported on cell-wall-deficient (CWD) bacteria which he called "mycoplasma" in AIDS tissue. He suspected these as a necessary "co-factor" for AIDS. Remarkably, Montagnier remained silent on Cantwell's reports of acid-fast bacteria which could simulate "mycoplasma" in AIDS tissue. Mattman makes clear that the differentiation between

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


    Denoncourt, Alix M.; Paquet, Valérie E.; Charette, Steve J.


    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...

  20. Endocarditis caused by anaerobic bacteria. (United States)

    Kestler, M; Muñoz, P; Marín, M; Goenaga, M A; Idígoras Viedma, P; de Alarcón, A; Lepe, J A; Sousa Regueiro, D; Bravo-Ferrer, J M; Pajarón, M; Costas, C; García-López, M V; Hidalgo-Tenorio, C; Moreno, M; Bouza, E


    Infective endocarditis (IE) caused by anaerobic bacteria is a rare and poorly characterized disease. Most data reported in the literature are from case reports [1-3]. Therefore, we assessed the situation of anaerobic IE (AIE) in Spain using the database of the Spanish Collaboration on Endocarditis (GAMES). We performed a prospective study from 2008 to 2016 in 26 Spanish centers. We included 2491 consecutive cases of definite IE (Duke criteria). Anaerobic bacteria caused 22 cases (0.9%) of definite IE. Median age was 66 years (IQR, 56-73), and 19 (86.4%) patients were men. Most patients (14 [63.6%]) had prosthetic valve IE and all episodes were left-sided: aortic valves, 12 (54.5%); and mitral valves, 8 (36.4%). The most common pathogens were Propionibacterium acnes (14 [63.6%]), Lactobacillus spp (3 [13.63%]), and Clostridium spp. (2 [9.0%]), and the infection was mainly odontogenic. Fifteen of the 22 patients (68.2%) underwent cardiac surgery. Mortality was 18.2% during admission and 5.5% after 1 year of follow-up. When patients with AIE were compared with the rest of the cohort, we found that although those with AIE had a similar age and Charlson comorbidity index, they were more likely to have community-acquired IE (86.4% vs. 60.9%, p = 0.01), have undergone cardiac surgery (68.2% vs 48.7% p = 0.06), and have had lower mortality rates during admission (18.2% vs. 27.3%). IE due to anaerobic bacteria is an uncommon disease that affects mainly prosthetic valves and frequently requires surgery. Otherwise, there are no major differences between AIE and IE caused by other microorganisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Bacteria and vampirism in cinema. (United States)

    Castel, O; Bourry, A; Thévenot, S; Burucoa, C


    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. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  2. Pathogenic mechanisms of intracellular bacteria. (United States)

    Niller, Hans Helmut; Masa, Roland; Venkei, Annamária; Mészáros, Sándor; Minarovits, Janos


    We wished to overview recent data on a subset of epigenetic changes elicited by intracellular bacteria in human cells. Reprogramming the gene expression pattern of various host cells may facilitate bacterial growth, survival, and spread. DNA-(cytosine C5)-methyltransferases of Mycoplasma hyorhinis targeting cytosine-phosphate-guanine (CpG) dinucleotides and a Mycobacterium tuberculosis methyltransferase targeting non-CpG sites methylated the host cell DNA and altered the pattern of gene expression. Gene silencing by CpG methylation and histone deacetylation, mediated by cellular enzymes, also occurred in M. tuberculosis-infected macrophages. M. tuberculosis elicited cell type-specific epigenetic changes: it caused increased DNA methylation in macrophages, but induced demethylation, deposition of euchromatic histone marks and activation of immune-related genes in dendritic cells. A secreted transposase of Acinetobacter baumannii silenced a cellular gene, whereas Mycobacterium leprae altered the epigenotype, phenotype, and fate of infected Schwann cells. The 'keystone pathogen' oral bacterium Porphyromonas gingivalis induced local DNA methylation and increased the level of histone acetylation in host cells. These epigenetic changes at the biofilm-gingiva interface may contribute to the development of periodontitis. Epigenetic regulators produced by intracellular bacteria alter the epigenotype and gene expression pattern of host cells and play an important role in pathogenesis.

  3. Money and transmission of bacteria. (United States)

    Gedik, Habip; Voss, Timothy A; Voss, Andreas


    Money is one of the most frequently passed items in the world. The aim of this study was to ascertain the survival status of bacteria including Staphylococcus aureus, Escherichia coli, and Vancomycin- Resistant Enterococci (VRE) on banknotes from different countries and the transmission of bacteria to people who come in contact with the banknotes. The survival rate was highest for the Romanian Leu yielding all three microorganisms used after both three and six hours of drying. Furthermore, the Leu was the only banknote to yield VRE after one day of drying. Other currencies either enabled the survival of Extended-Spectrum Beta-Lactamases (ESBL) and VRE (e.g. Euro), but not of MRSA, or the other way round (e.g. US Dollar). While a variety of factors such as community hygiene levels, people's behaviour, and antimicrobial resistance rates at community level obviously have influence on the transmission of resistant microorganisms, the type of banknote-paper may be an additional variable to consider.

  4. Resistance of Bacteria to Biocides. (United States)

    Maillard, Jean-Yves


    Biocides and formulated biocides are used worldwide for an increasing number of applications despite tightening regulations in Europe and in the United States. One concern is that such intense usage of biocides could lead to increased bacterial resistance to a product and cross-resistance to unrelated antimicrobials including chemotherapeutic antibiotics. Evidence to justify such a concern comes mostly from the use of health care-relevant bacterial isolates, although the number of studies of the resistance characteristics of veterinary isolates to biocides have increased the past few years. One problem remains the definition of "resistance" and how to measure resistance to a biocide. This has yet to be addressed globally, although the measurement of resistance is becoming more pressing, with regulators both in Europe and in the United States demanding that manufacturers provide evidence that their biocidal products will not impact on bacterial resistance. Alongside in vitro evidence of potential antimicrobial cross-resistance following biocide exposure, our understanding of the mechanisms of bacterial resistance and, more recently, our understanding of the effect of biocides to induce a mechanism(s) of resistance in bacteria has improved. This article aims to provide an understanding of the development of antimicrobial resistance in bacteria following a biocide exposure. The sections provide evidence of the occurrence of bacterial resistance and its mechanisms of action and debate how to measure bacterial resistance to biocides. Examples pertinent to the veterinary field are used where appropriate.

  5. Differential scanning calorimetry of bacteria. (United States)

    Miles, C A; Mackey, B M; Parsons, S E


    Thermograms obtained by differential scanning calorimetry of a range of bacteria of different heat resistances were compared. Equations were derived to calculate the rate at which the numbers of viable organisms in a calorimeter decline as the temperature is raised at a constant rate. Vegetative bacteria scanned at 10 degrees C min-1 showed multi-peaked thermograms with four major peaks (denoted m, n, p and q) occurring in the regions 68-73, 77-84, 89-99 and 105-110 degrees C respectively. Exceptions were that peak m (the largest peak) occurred at 79-82 degrees C in Bacillus stearothermophilus and an additional peak, r, was detected in Escherichia coli at 119 degrees C. At temperatures below the main peak m there were major differences in thermograms between species. There was a direct relationship between the onset of thermal denaturation and the thermoresistance of different organisms. Heat-sensitive organisms displayed thermogram features which were absent in the more heat-resistant types. When samples were cooled to 5 degrees C and re-heated, a small endothermic peak, pr, was observed at the same temperature as p. Peaks p and pr were identified as the melting endotherms of DNA. In all vegetative organisms examined, maximum death rates, computed from published D and z values, occurred at temperatures above the onset of thermal denaturation, i.e. cell death and irreversible denaturation of cell components occurred within the same temperature range.

  6. Isolation and characterization of two novel ethanol-tolerant facultative-anaerobic thermophilic bacteria strains from waste compost. (United States)

    Fong, Jiunn C N; Svenson, Charles J; Nakasugi, Kenlee; Leong, Caine T C; Bowman, John P; Chen, Betty; Glenn, Dianne R; Neilan, Brett A; Rogers, Peter L


    In a search for potential ethanologens, waste compost was screened for ethanol-tolerant thermophilic microorganisms. Two thermophilic bacterial strains, M5EXG and M10EXG, with tolerance of 5 and 10% (v/v) ethanol, respectively, were isolated. Both isolates are facultative anaerobic, non-spore forming, non-motile, catalase-positive, oxidase-negative, Gram-negative rods that are capable of utilizing a range of carbon sources including arabinose, galactose, mannose, glucose and xylose and produce low amounts of ethanol, acetate and lactate. Growth of both isolates was observed in fully defined minimal media within the temperature range 50-80 degrees C and pH 6.0-8.0. Phylogenetic analysis of the 16S rDNA sequences revealed that both isolates clustered with members of subgroup 5 of the genus Bacillus. G+C contents and DNA-DNA relatedness of M5EXG and M10EXG revealed that they are strains belonging to Geobacillus thermoglucosidasius. However, physiological and biochemical differences were evident when isolates M5EXG and M10EXG were compared with G. thermoglucosidasius type strain (DSM 2542(T)). The new thermophilic, ethanol-tolerant strains of G. thermoglucosidasius may be candidates for ethanol production at elevated temperatures.

  7. Sulfur metabolism in phototrophic sulfur bacteria

    DEFF Research Database (Denmark)

    Frigaard, Niels-Ulrik; Dahl, Christiane


    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...

  8. Agrobacterium deltaense sp. nov., an endophytic bacteria isolated from nodule of Sesbania cannabina. (United States)

    Yan, Jun; Li, Yan; Han, Xiao Zeng; Chen, Wen Feng; Zou, Wen Xiu; Xie, Zhihong; Li, Meng


    A Gram-negative, non-spore-forming, aerobic rods, strain YIC4121 T , was isolated from root nodule of Sesbania cannabina grown in Dongying (Yellow River Delta), Shandong Province, PR China. Based on phylogenetic analysis of 16 S rRNA gene sequences, strain YIC4121 T was assigned to the genus Agrobacterium with 99.7, 99.3, 99.0, 98.8 and 98.7% sequence similarities to Agrobacterium radiobacter LMG140 T , A. pusense NRCPB10 T , A. arsenijevicii KFB 330 T , A. nepotum 39/7 T and A. larrymoorei ATCC51759 T . Analysis of the concatenated housekeeping genes (recA-atpD-glnII), showed lower sequence similarities (≤94.6%) between strain YIC4121 T and other recognized Agrobacterium species. Strain YIC4121 T shared whole-genome average nucleotide identities (ANI) 87.94, 91.27 and 77.42%, with A. pusense NRCPB10 T , A. radiobacter LMG140 T and A. larrymoorei ATCC51759 T . The predominant cellular fatty acids were C 19:0 cyclo ω8c, summed feature 2 (C 12:0 aldehyde/unknown 10.9525), summed feature 8 (C 18:1 ω7c/C 18:1 ω6c), C 16:0 3 OH and C 16:0 . The G + C content of strain YIC4121 T was 59.80 mol%. Tween 80, lactulose, citric acid, α-ketoglutaric acid, glycyl-L-glutamic acid and 2, 3-butanediol could not be utilized as carbon source, distinguishing strain YIC4121 T from the other related species. Based on the distinctly genetic and phenotypic dissimilarity, a novel species Agrobacterium deltaense sp. nov. is proposed with YIC4121 T (=HAMBI 3654 T  = LMG 29283 T ) as the type strain.

  9. PCR-based detection of resistance genes in anaerobic bacteria isolated from intra-abdominal infections. (United States)

    Tran, Chau Minh; Tanaka, Kaori; Watanabe, Kunitomo


    Little information is available on the distribution of antimicrobial resistance genes in anaerobes in Japan. To understand the background of antimicrobial resistance in anaerobes involved in intra-abdominal infections, we investigated the distribution of eight antimicrobial resistance genes (cepA, cfiA, cfxA, ermF, ermB, mefA, tetQ, and nim) and a mutation in the gyrA gene in a total of 152 organisms (Bacteroides spp., Prevotella spp., Fusobacterium spp., Porphyromonas spp., Bilophila wadsworthia, Desulfovibrio desulfuricans, Veillonella spp., gram-positive cocci, and non-spore-forming gram-positive bacilli) isolated between 2003 and 2004 in Japan. The cepA gene was distributed primarily in Bacteroides fragilis. Gene cfxA was detected in about 9 % of the Bacteroides isolates and 75 % of the Prevotella spp. isolates and did not appear to contribute to cephamycin resistance. Two strains of B. fragilis contained the metallo-β-lactamase gene cfiA, but they did not produce the protein product. Gene tetQ was detected in about 81, 44, and 63 % of B. fragilis isolates, other Bacteroides spp., and Prevotella spp. isolates, respectively. The ermF gene was detected in 25, 13, 56, 64, and 16 % of Bacteroides spp., Prevotella spp., Fusobacterium spp., B. wadsworthia, and anaerobic cocci, respectively. Gene mefA was found in only 10 % of the B. fragilis strains and 3 % of the non-B. fragilis strains. Genes nim and ermB were not detected in any isolate. Substitution at position 82 (Ser to Phe) in gyrA was detected in B. fragilis isolates that were less susceptible or resistant to moxifloxacin. This study is the first report on the distribution of resistance genes in anaerobes isolated from intra-abdominal infections in Japan. We expect that the results might help in understanding the resistance mechanisms of specific anaerobes.

  10. Bactericide for sulfate-reducing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Shklyar, T F; Anoshina, G M; Blokhin, V Ye; Kisarrev, Ye L; Novikovsa, G M


    The aim of the invention is to find a bactericide for sulfate-reducing bacteria of oil fields in Western Siberia in order to suppress the biocorrosive activity on oil industry equipment. This goal is achieved by using M-nitroacetanylide as the bactericide of sulfate-reducing bacteria. This agent suppresses the activity of a stored culture of sulfate-reducing bacteria that comes from industrial waste waters injection wells of the Smotlor oil field.

  11. Differential staining of bacteria: acid fast stain. (United States)

    Reynolds, Jackie; Moyes, Rita B; Breakwell, Donald P


    Acid-fastness is an uncommon characteristic shared by the genera Mycobacterium (Section 10A) and Nocardia. Because of this feature, this stain is extremely helpful in identification of these bacteria. Although Gram positive, acid-fast bacteria do not take the crystal violet into the wall well, appearing very light purple rather than the deep purple of normal Gram-positive bacteria. (c) 2009 by John Wiley & Sons, Inc.

  12. Transformation of gram positive bacteria by sonoporation (United States)

    Yang, Yunfeng; Li, Yongchao


    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.

  13. Magnetotactic bacteria at the geomagnetic equator

    International Nuclear Information System (INIS)

    Frankel, R.B.; Blakemore, R.P.; Araujo, F.F.T. de; Esquivel, D.M.S.; Danon, J.


    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) [pt

  14. Bioenergetics of photoheterotrophic bacteria in the oceans. (United States)

    Kirchman, David L; Hanson, Thomas E


    Photoheterotrophic microbes, such as proteorhodopsin (PR)-based phototrophic (PRP) and aerobic anoxygenic phototrophic (AAP) bacteria, are well known to be abundant in the oceans, potentially playing unique roles in biogeochemical cycles. However, the contribution of phototrophy to the energy requirements of these bacteria has not been quantitatively examined to date. To better understand the implications of photoheterophy in the oceans, we calculated energy benefits and costs of phototrophy and compared net benefits with maintenance costs. Benefits depend on the number of photosynthetic units (PSUs), absorption cross-section area of each PSU as function of wavelength, the in situ light quality, and the energy yield per absorbed photon. For costs we considered the energy required for the synthesis of pigments, amino acids and proteins in each PSU. Our calculations indicate that AAP bacteria harvest more light energy than do PRP bacteria, but the costs of phototrophy are much higher for AAP bacteria. Still, the net energy gained by AAP bacteria is often sufficient to meet maintenance costs, while that is not the case for PRP bacteria except with high light intensities and large numbers of proteorhodopsin molecules per cell. The low costs and simplicity of PR-based phototrophy explain the high abundance of proteorhodopsin genes in the oceans. However, even for AAP bacteria, the net energy yield of phototrophy is apparently too low to influence the distribution of photoheterotrophic bacteria among various marine systems. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  15. Quorum sensing in gram-negative bacteria

    DEFF Research Database (Denmark)

    Wu, H.; Song, Z.J.; Høiby, N.


    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...

  16. Isolation and characterization of methanogenic bacteria from ...

    African Journals Online (AJOL)

    Isolation and characterization of methanogenic bacteria from brewery wastewater in Kenya. Sylvia Injete Murunga, Duncan Onyango Mbuge, Ayub Njoroge Gitau, Urbanus Ndungwa Mutwiwa, Ingrid Namae Wekesa ...

  17. Fewer bacteria in warm water

    International Nuclear Information System (INIS)

    Bagh, Lene


    There has been many suggestions to how the ideal warm water system should be. Particularly whether warm water containers or heat exchangers in larger houses are the best solutions in order to maintain a water quality with low levels of bacteria. In an investigation made by Statens Byggeforskningsinstitutt (Denmark) regarding ''Bacterial growth in warm water installations with heat exchangers'' there were used several heat exchangers made by Gjelsted and Lund of three of which had HWAT heating cables. The bacterial content was low from these exchangers compared to exchangers with circulation. The article presents promising results from a study where the method was investigated over a longer period in two new larger warm water systems. Some energy conservation aspects are discussed

  18. Modeling Political Populations with Bacteria (United States)

    Cleveland, Chris; Liao, David


    Results from lattice-based simulations of micro-environments with heterogeneous nutrient resources reveal that competition between wild-type and GASP rpoS819 strains of E. Coli offers mutual benefit, particularly in nutrient deprived regions. Our computational model spatially maps bacteria populations and energy sources onto a set of 3D lattices that collectively resemble the topology of North America. By implementing Wright-Fishcer re- production into a probabilistic leap-frog scheme, we observe populations of wild-type and GASP rpoS819 cells compete for resources and, yet, aid each other's long term survival. The connection to how spatial political ideologies map in a similar way is discussed.

  19. Cell Size Regulation in Bacteria (United States)

    Amir, Ariel


    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. Antioxidant Properties of Probiotic Bacteria. (United States)

    Wang, Yang; Wu, Yanping; Wang, Yuanyuan; Xu, Han; Mei, Xiaoqiang; Yu, Dongyou; Wang, Yibing; Li, Weifen


    Oxidative stress defines a condition in which the prooxidant-antioxidant balance in the cell is disturbed, resulting in DNA hydroxylation, protein denaturation, lipid peroxidation, and apoptosis, ultimately compromising cells' viability. Probiotics have been known for many beneficial health effects, and the consumption of probiotics alone or in food shows that strain-specific probiotics can present antioxidant activity and reduce damages caused by oxidation. However, the oxidation-resistant ability of probiotics, especially the underling mechanisms, is not properly understood. In this view, there is interest to figure out the antioxidant property of probiotics and summarize the mode of action of probiotic bacteria in antioxidation. Therefore, in the present paper, the antioxidant mechanisms of probiotics have been reviewed in terms of their ability to improve the antioxidant system and their ability to decrease radical generation. Since in recent years, oxidative stress has been associated with an altered gut microbiota, the effects of probiotics on intestinal flora composition are also elaborated.

  1. Sterol Synthesis in Diverse Bacteria. (United States)

    Wei, Jeremy H; Yin, Xinchi; Welander, Paula V


    Sterols are essential components of eukaryotic cells whose biosynthesis and function has been studied extensively. Sterols are also recognized as the diagenetic precursors of steranes preserved in sedimentary rocks where they can function as geological proxies for eukaryotic organisms and/or aerobic metabolisms and environments. However, production of these lipids is not restricted to the eukaryotic domain as a few bacterial species also synthesize sterols. Phylogenomic studies have identified genes encoding homologs of sterol biosynthesis proteins in the genomes of several additional species, indicating that sterol production may be more widespread in the bacterial domain than previously thought. Although the occurrence of sterol synthesis genes in a genome indicates the potential for sterol production, it provides neither conclusive evidence of sterol synthesis nor information about the composition and abundance of basic and modified sterols that are actually being produced. Here, we coupled bioinformatics with lipid analyses to investigate the scope of bacterial sterol production. We identified oxidosqualene cyclase (Osc), which catalyzes the initial cyclization of oxidosqualene to the basic sterol structure, in 34 bacterial genomes from five phyla (Bacteroidetes, Cyanobacteria, Planctomycetes, Proteobacteria, and Verrucomicrobia) and in 176 metagenomes. Our data indicate that bacterial sterol synthesis likely occurs in diverse organisms and environments and also provides evidence that there are as yet uncultured groups of bacterial sterol producers. Phylogenetic analysis of bacterial and eukaryotic Osc sequences confirmed a complex evolutionary history of sterol synthesis in this domain. Finally, we characterized the lipids produced by Osc-containing bacteria and found that we could generally predict the ability to synthesize sterols. However, predicting the final modified sterol based on our current knowledge of sterol synthesis was difficult. Some bacteria

  2. Characterization of Bacteria Isolation of Bacteria from Pinyon Rhizosphere, (United States)


    Two hundred and fifty bacterial strains were isolated from pinyon rhizosphere and screened for biosurfactants production. Among them, six bacterial strains were selected for their potential to produce biosurfactants using two low cost wastes, crude glycerol and lactoserum, as raw material. Both wastes were useful for producing biosurfactants because of their high content in fat and carbohydrates. The six strains were identified by 16S rDNA with an identity percentage higher than 95%, three strains belonged to Enterobacter sp., Pseudomonas aeruginosa, Bacillus pumilus and Rhizobium sp. All strains assayed were able to grow and showed halos around the colonies as evidence of biosurfactants production on Cetyl Trimethyl Ammonium Bromide agar with crude glycerol and lactoserum as substrate. In a mineral salt liquid medium enriched with both wastes, the biosurfactants were produced and collected from free cell medium after 72 h incubation. The biosurfactants produced reduced the surface tension from 69 to 30 mN/m with an emulsification index of diesel at approximately 60%. The results suggest that biosurfactants produced by rhizosphere bacteria from pinyon have promising environmental applications.

  3. Characterization of (per)chlorate-reducing bacteria

    NARCIS (Netherlands)

    Wolterink, A.F.W.M.


    Some bacteria can use (per)chlorateas terminal electron acceptor for growth. These bacteria convert perchlorate via chlorate and chlorite into chloride and molecular oxygen. Oxygen formation in microbial respiration is unique. In this study two chlorate-reducing strains

  4. Rapid methods for detection of bacteria

    DEFF Research Database (Denmark)

    Corfitzen, Charlotte B.; Andersen, B.Ø.; Miller, M.


    Traditional methods for detection of bacteria in drinking water e.g. Heterotrophic Plate Counts (HPC) or Most Probable Number (MNP) take 48-72 hours to give the result. New rapid methods for detection of bacteria are needed to protect the consumers against contaminations. Two rapid methods...

  5. Rock-degrading endophytic bacteria in cacti (United States)

    M. Esther Puente; Ching Y. Li; Yoav Bashan


    A plant-bacterium association of the cardon cactus (Pachycereus pringlei) and endophytic bacteria promotes establishment of seedlings and growth on igneous rocks without soil. These bacteria weather several rock types and minerals, unbind significant amounts of useful minerals for plants from the rocks, fix in vitro N2. produce...

  6. Comparative Genomics of Green Sulfur Bacteria

    DEFF Research Database (Denmark)

    Ussery, David; Davenport, C; Tümmler, B


    Eleven completely sequenced Chlorobi genomes were compared in oligonucleotide usage, gene contents, and synteny. The green sulfur bacteria (GSB) are equipped with a core genome that sustains their anoxygenic phototrophic lifestyle by photosynthesis, sulfur oxidation, and CO(2) fixation. Whole...... weight of 10(6), and are probably instrumental for the bacteria to generate their own intimate (micro)environment....

  7. Analyzing Arthropods for the Presence of Bacteria


    Andrews, Elizabeth S.


    Bacteria within arthropods can be identified using culture-independent methods. This unit describes protocols for surface sterilization of arthropods, DNA extraction of whole bodies and tissues, touchdown PCR amplification using 16S rDNA general bacteria primers and profiling the bacterial community using denaturing gradient gel electrophoresis.

  8. Resuscitation effects of catalase on airborne bacteria.


    Marthi, B; Shaffer, B T; Lighthart, B; Ganio, L


    Catalase incorporation into enumeration media caused a significant increase (greater than 63%) in the colony-forming abilities of airborne bacteria. Incubation for 30 to 60 min of airborne bacteria in collection fluid containing catalase caused a greater than 95% increase in colony-forming ability. However, catalase did not have any effects on enumeration at high relative humidities (80 to 90%).

  9. Catabolism of lysine by mixed rumen bacteria

    International Nuclear Information System (INIS)

    Onodera, Ryoji; Kandatsu, Makoto.


    Metabolites arising from the catabolism of lysine by the mixed rumen bacteria were chromatographically examined by using radioactive lysine. After 6 hr incubation, 241 nmole/ml of lysine was decomposed to give ether-soluble substances and CO 2 by the bacteria and 90 nmole/ml of lysine was incorporated unchanged into the bacteria. delta-Aminovalerate, cadaverine or pipecolate did not seem to be produced from lysine even after incubation of the bacteria with addition of those three amino compounds to trap besides lysine and radioactive lysine. Most of the ether-soluble substances produced from radioactive lysine was volatile fatty acids (VFAs). Fractionation of VFAs revealed that the peaks of butyric and acetic acids coincided with the strong radioactive peaks. Small amounts of radioactivities were detected in propionic acid peak and a peak assumed to be caproic acid. The rumen bacteria appeared to decompose much larger amounts of lysine than the rumen ciliate protozoa did. (auth.)

  10. Biodiversity of Bacteria Isolated from Different Soils

    Directory of Open Access Journals (Sweden)

    Fatma YAMAN


    Full Text Available The aim of this study was to determine the biodiversity of PHB producing bacteria isolated from soils where fruit and vegetable are cultivated (onion, grape, olive, mulberry and plum in Aydın providence. Morphological, cultural, biochemical, and molecular methods were used for bacteria identification. These isolated bacteria were identified by 16S rRNA sequencing and using BLAST. The following bacteria Bacillus thuringiensis (6, Bacillus cereus (8, Bacillus anthrachis (1, Bacillus circulans (1, Bacillus weihenstephanensis (1, Pseudomonas putida (1, Azotobacter chroococcum (1, Brevibacterium frigoritolerans (1, Burkholderia sp. (1, Staphylococcus epidermidis (1, Streptomyces exfoliatus (1, Variovorax paradoxus (1 were found. The Maximum Likelihood method was used to produce a molecular phylogenetic analysis and a phylogenetic tree was constructed. These bacteria can produce polyhydroxybutyrate (PHB which is an organic polymer with commercial potential as a biodegradable thermoplastic. PHB can be used instead of petrol derivated non-degradable plastics. For this reason, PHB producing microorganisms are substantial in industry.


    Energy Technology Data Exchange (ETDEWEB)

    Brigmon, R; Topher Berry, T; Grazyna A. Plaza, G; jacek Wypych, j


    Fate of benzene ethylbenzene toluene xylenes (BTEX) compounds through biodegradation was investigated using two different bacteria, Ralstonia picketti (BP-20) and Alcaligenes piechaudii (CZOR L-1B). These bacteria were isolated from extremely polluted petroleum hydrocarbon contaminated soils. PCR and Fatty Acid Methyl Ester (FAME) were used to identify the isolates. Biodegradation was measured using each organism individually and in combination. Both bacteria were shown to degrade each of the BTEX compounds. Alcaligenes piechaudii biodegraded BTEXs more efficiently while mixed with BP-20 and individually. Biosurfactant production was observed by culture techniques. In addition 3-hydroxy fatty acids, important in biosurfactant production, was observed by FAME analysis. In the all experiments toluene and m+p- xylenes were better growth substrates for both bacteria than the other BTEX compounds. In addition, the test results indicate that the bacteria could contribute to bioremediation of aromatic hydrocarbons (BTEX) pollution increase biodegradation through the action by biosurfactants.

  12. Coryneform bacteria associated with canine otitis externa

    DEFF Research Database (Denmark)

    Aalbæk, Bent; Bemis, David A.; Schjærff, Mette


    This study aims to investigate the occurrence of coryneform bacteria in canine otitis externa. A combined case series and case-control study was carried out to improve the current knowledge on frequency and clinical significance of coryneform bacteria in samples from canine otitis externa. A total...... of 16 cases of otitis externa with involvement of coryneform bacteria were recorded at two referral veterinary hospitals in Denmark and the US, respectively. Coryneform bacteria were identified by partial 16S rRNA gene sequencing. Corynebacterium auriscanis was the most common coryneform species (10...... cases). Small colony variants of this species were also observed. Other coryneform isolates were identified as Corynebacterium amycolatum (3 cases), Corynebacterium freneyi (2 cases) and an Arcanobacterium-like species (1 case). The coryneform bacteria were in all cases isolated together with other...

  13. Hyphae colonizing bacteria associated with Penicillium bilaii

    DEFF Research Database (Denmark)

    Ghodsalavi, Behnoushsadat

    shown that mycorrhizal helper bacteria presenting in mycorrhizal fungi could stimulate fungal growth, promote establishment of root-fungus symbiosis and enhance plant production. But it is unknown if the comparable relationship exist between the non-mycorrhizal fungus P. bilaii and its hyphae associated...... bacteria. In the current PhD thesis, we assumed that hyphae-associated microbiome of P. bilaii might harbor helper bacteria with ability to improve fungal growth and P solubilization performance. Therefore, we aimed to isolate bacteria associated with the P. bilaii hyphae and identify the fungal growth...... stimulating bacteria with the perspective of promoting efficiency of Jumpstart in soil – plant system. For this purpose, most of the work within the current project was carried out by development of suitable model systems by mimicking the natural soil habitat to reach to the reliable performance in soil...

  14. [Unique properties of highly radioresistant bacteria]. (United States)

    Romanovskaia, V A; Rokitko, P V; Malashenko, Iu R


    In connection with the Chernobyl Nuclear Power Plant (ChNPP) accident and the negative ecological after-effects for biota in this zone the interest has arisen to radioresistant bacteria, as to the most dynamic model of the given ecosystem, and to mechanisms which provide resistance of bacteria to ionizing radiation. The analysis of published data has shown that the radioresistant bacteria are not interrelated taxonomically and phylogenetically. The extreme radioresistant bacteria are represented by the Deinococcus species, which form a group phylogenetically close to the line Thermus-Meiothermus. Other radioresistant bacteria are the representatives of the genera Rubrobacter, Methylobacterium, Kocuria, Bacillus and some archebacteria. Data on natural habitats, of radioresistant bacteria are not numerous. In a number of cases it is difficult to distinguish their natural habitats, as they were isolated from the samples which were previously exposed to X-ray or gamma-irradiation, or from the ecosystems with the naturally raised radioactivity. To understand the strategy of survival of radioresistant bacteria, we briefly reviewed the mechanism of action of various species of radiation on cells and macromolecules; physiological signs of the cell damage caused by radiation; mechanisms eliminating (repairing) these damages. More details on mechanisms of the DNA repair in D. radiodurans are described. The extreme resistance of D. radiodurans to the DNA damaging factors is defined by 1) repair mechanisms which fundamentally differ from those in other procaryotes; 2) ability to increase the efficiency of a standard set of the DNA repairing proteins. Literary and own data on the effect of radiation on survival of various groups of bacteria in natural ecosystems are summarized. The ecological consequences of the ChNPP accident for soil bacteria in this region were estimated. The reduction of the number of soil bacteria and recession of microbial diversity under the effect of

  15. Comparative cytotoxicity of periodontal bacteria

    International Nuclear Information System (INIS)

    Stevens, R.H.; Hammond, B.F.


    The direct cytotoxicity of sonic extracts (SE) from nine periodontal bacteria for human gingival fibroblasts (HGF) was compared. Equivalent dosages (in terms of protein concentration) of SE were used to challenge HGF cultures. The cytotoxic potential of each SE was assessed by its ability to (1) inhibit HGF proliferation, as measured by direct cell counts; (2) inhibit 3H-thymidine incorporation in HGF cultures; or (3) cause morphological alterations of the cells in challenged cultures. The highest concentration (500 micrograms SE protein/ml) of any of the SEs used to challenge the cells was found to be markedly inhibitory to the HGFs by all three of the criteria of cytotoxicity. At the lowest dosage tested (50 micrograms SE protein/ml); only SE from Actinobacillus actinomycetemcomitans, Bacteroides gingivalis, and Fusobacterium nucleatum caused a significant effect (greater than 90% inhibition or overt morphological abnormalities) in the HGFs as determined by any of the criteria employed. SE from Capnocytophaga sputigena, Eikenella corrodens, or Wolinella recta also inhibited cell proliferation and thymidine incorporation at this dosage; however, the degree of inhibition (5-50%) was consistently, clearly less than that of the first group of three organisms named above. The SE of the three other organisms tested (Actinomyces odontolyticus, Bacteroides intermedius, and Streptococcus sanguis) had little or no effect (0-10% inhibition) at this concentration. The data suggest that the outcome of the interaction between bacterial components and normal resident cells of the periodontium is, at least in part, a function of the bacterial species

  16. Tape Cassette Bacteria Detection System (United States)


    The design, fabrication, and testing of an automatic bacteria detection system with a zero-g capability and based on the filter-capsule approach is described. This system is intended for monitoring the sterility of regenerated water in a spacecraft. The principle of detection is based on measuring the increase in chemiluminescence produced by the action of bacterial porphyrins (i.e., catalase, cytochromes, etc.) on a luminol-hydrogen peroxide mixture. Since viable as well as nonviable organisms initiate this luminescence, viable organisms are detected by comparing the signal of an incubated water sample with an unincubated control. Higher signals for the former indicate the presence of viable organisms. System features include disposable sealed sterile capsules, each containing a filter membrane, for processing discrete water samples and a tape transport for moving these capsules through a processing sequence which involves sample concentration, nutrient addition, incubation, a 4 Molar Urea wash and reaction with luminol-hydrogen peroxide in front of a photomultiplier tube. Liquids are introduced by means of a syringe needle which pierces a rubber septum contained in the wall of the capsule. Detection thresholds obtained with this unit towards E. coli and S. marcescens assuming a 400 ml water sample are indicated.

  17. Antioxidant Properties of Probiotic Bacteria

    Directory of Open Access Journals (Sweden)

    Yang Wang


    Full Text Available Oxidative stress defines a condition in which the prooxidant–antioxidant balance in the cell is disturbed, resulting in DNA hydroxylation, protein denaturation, lipid peroxidation, and apoptosis, ultimately compromising cells’ viability. Probiotics have been known for many beneficial health effects, and the consumption of probiotics alone or in food shows that strain-specific probiotics can present antioxidant activity and reduce damages caused by oxidation. However, the oxidation-resistant ability of probiotics, especially the underling mechanisms, is not properly understood. In this view, there is interest to figure out the antioxidant property of probiotics and summarize the mode of action of probiotic bacteria in antioxidation. Therefore, in the present paper, the antioxidant mechanisms of probiotics have been reviewed in terms of their ability to improve the antioxidant system and their ability to decrease radical generation. Since in recent years, oxidative stress has been associated with an altered gut microbiota, the effects of probiotics on intestinal flora composition are also elaborated.

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

    Directory of Open Access Journals (Sweden)

    Alix M Denoncourt


    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.

  19. Bacteria classification using Cyranose 320 electronic nose

    Directory of Open Access Journals (Sweden)

    Gardner Julian W


    Full Text Available Abstract Background An electronic nose (e-nose, the Cyrano Sciences' Cyranose 320, comprising an array of thirty-two polymer carbon black composite sensors has been used to identify six species of bacteria responsible for eye infections when present at a range of concentrations in saline solutions. Readings were taken from the headspace of the samples by manually introducing the portable e-nose system into a sterile glass containing a fixed volume of bacteria in suspension. Gathered data were a very complex mixture of different chemical compounds. Method Linear Principal Component Analysis (PCA method was able to classify four classes of bacteria out of six classes though in reality other two classes were not better evident from PCA analysis and we got 74% classification accuracy from PCA. An innovative data clustering approach was investigated for these bacteria data by combining the 3-dimensional scatter plot, Fuzzy C Means (FCM and Self Organizing Map (SOM network. Using these three data clustering algorithms simultaneously better 'classification' of six eye bacteria classes were represented. Then three supervised classifiers, namely Multi Layer Perceptron (MLP, Probabilistic Neural network (PNN and Radial basis function network (RBF, were used to classify the six bacteria classes. Results A [6 × 1] SOM network gave 96% accuracy for bacteria classification which was best accuracy. A comparative evaluation of the classifiers was conducted for this application. The best results suggest that we are able to predict six classes of bacteria with up to 98% accuracy with the application of the RBF network. Conclusion This type of bacteria data analysis and feature extraction is very difficult. But we can conclude that this combined use of three nonlinear methods can solve the feature extraction problem with very complex data and enhance the performance of Cyranose 320.

  20. Folate Production by Probiotic Bacteria

    Directory of Open Access Journals (Sweden)

    Stefano Raimondi


    Full Text Available 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-type lactobacilli cannot synthesize folate, generally require it for growth, and provide a negative contribution to folate levels in fermented dairy products. Lactobacillus plantarum constitutes an exception among lactobacilli, since it is capable of folate production in presence of para-aminobenzoic acid (pABA and deserves to be used in animal trials to validate its ability to produce the vitamin in vivo. On the other hand, several folate-producing strains have been selected within the genus Bifidobacterium, with a great variability in the extent of vitamin released in the medium. Most of them belong to the species B. adolescentis and B. pseudocatenulatum, but few folate producing strains are found in the other species as well. Rats fed a probiotic formulation of folate-producing bifidobacteria exhibited increased plasma folate level, confirming that the vitamin is produced in vivo and absorbed. In a human trial, the same supplement raised folate concentration in feces. The use of folate-producing probiotic strains can be regarded as a new perspective in the specific use of probiotics. They could more efficiently confer protection against inflammation and cancer, both exerting the beneficial effects of probiotics and preventing the folate deficiency that is associated with premalignant changes in the colonic epithelia.

  1. Magnetotactic Bacteria from Extreme Environments

    Directory of Open Access Journals (Sweden)

    Christopher T. Lefèvre


    Full Text Available 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 aquatic habitats and it is currently thought that magnetosomes function as a means of making chemotaxis more efficient in locating and maintaining an optimal position for growth and survival at the OAI. Known cultured and uncultured MTB are phylogenetically associated with the Alpha-, Gamma- and Deltaproteobacteria classes of the phylum Proteobacteria, the Nitrospirae phylum and the candidate division OP3, part of the Planctomycetes-Verrucomicrobia-Chlamydiae (PVC bacterial superphylum. MTB are generally thought to be ubiquitous in aquatic environments as they are cosmopolitan in distribution and have been found in every continent although for years MTB were thought to be restricted to habitats with pH values near neutral and at ambient temperature. Recently, however, moderate thermophilic and alkaliphilic MTB have been described including: an uncultured, moderately thermophilic magnetotactic bacterium present in hot springs in northern Nevada with a probable upper growth limit of about 63 °C; and several strains of obligately alkaliphilic MTB isolated in pure culture from different aquatic habitats in California, including the hypersaline, extremely alkaline Mono Lake, with an optimal growth pH of >9.0.

  2. Fermentative Bacteria Influence the Competition between Denitrifiers and DNRA Bacteria

    Directory of Open Access Journals (Sweden)

    Eveline M. van den Berg


    results of this study clearly show that not only the ratio of available substrates, but also the nature of the electron donor influences the outcome of competition between DNRA and denitrification. Apparently, fermentative bacteria are competitive for the electron donor and thereby alter the ratio of available substrates for nitrate reduction.

  3. The Microworld of Marine-Bacteria

    DEFF Research Database (Denmark)



    Microsensor studies show that the marine environment in the size scale of bacteria is physically and chemically very different from the macroenvironment. The microbial world of the sediment-water interface is thus dominated by water viscosity and steep diffusion gradients. Because of the diverse...... metabolism types, bacteria in the mostly anoxic sea floor play an important role in the major element cycles of the ocean. The communities of giant, filamentous sulfur bacteria that live in the deep-sea hydrothermal vents or along the Pacific coast of South America are presented here as examples....

  4. Labelling of bacteria with indium chelates

    International Nuclear Information System (INIS)

    Kleinert, P.; Pfister, W.; Endert, G.; Sproessig, M.


    The indium chelates were prepared by reaction of radioactive indiumchloride with 10 μg oxine, 15 μg tropolone and 3 mg acetylacetone, resp. The formed chelates have been incubated with 10 9 germs/ml for 5 minutes, with labelling outputs from 90 to 95%. Both gram-positive (Streptococcus, Staphylococcus) and gram-negative bacteria (Escherichia coli) can be labelled. The reproductive capacity of the bacteria was not impaired. The application of indium labelled bacteria allows to show the distribution of microorganisms within the living organism and to investigate problems of bacterial adherence. (author)

  5. Mortality of fecal bacteria in seawater

    International Nuclear Information System (INIS)

    Garcia-Lara, J.; Menon, P.; Servais, P.; Billen, G.


    The authors 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 trichloracetic acid-insoluble fraction in water samples to which [ 3 H]thymidine-prelabeled allochthonous bacteria have been added. In coastal seawater, they found that the actual rate of disappearance of fecal bacteria was 1 order of magnitude lower than the rate of loss of culturability on specific media. Minor adaptation of the procedure may facilitate assessment of the effect of protozoan grazing and bacteriophage lysis on the overall bacterial mortality rate

  6. Pu sorption to activated conglomerate anaerobic bacteria

    International Nuclear Information System (INIS)

    Sasaki, Takayuki; Kudo, Akira


    The sorption of Pu to the anaerobic bacteria activated under specific conditions of temperature, pH and depleted nutrients after long dormant period was investigated. After 4 h at neutral pH, the distribution coefficient (K d ) between bacteria and aqueous phase at 308 and 278 K had around 10 3 to 10 4 . After over 5 days, however, the K d at only 308 K had increased to over 10 5 . Sterilized (dead) and dormant anaerobic bacteria adsorbed Pu to the same extent. (author)

  7. Bacteria Culture Test: MedlinePlus Lab Test Information (United States)

    ... this page: Bacteria Culture Test To use the sharing features on this page, please enable JavaScript. What is a Bacteria Culture Test? Bacteria are a large group of ...

  8. Flow cytometry, fluorescent probes, and flashing bacteria

    NARCIS (Netherlands)

    Bunthof, C.J.


    Key words: fluorescent probes, flow cytometry, CSLM, viability, survival, microbial physiology, lactic acid bacteria, Lactococcus lactis , Lactobacillus plantarum , cheese, milk,

  9. Effect of leukocyte hydrolases on bacteria

    International Nuclear Information System (INIS)

    Cohen, D.; Michel, J.; Ferne, M.; Bergner-Rabinowitz, S.; Ginsburg, I.


    Leukocyte extracts, trypsin, and lysozyme are all capable of releasing the bulk of the LPS from S. typhi, S. typhimurium, and E. coli. Bacteria which have been killed by heat, ultraviolet irradiation, or by a variety of metabolic inhibitors and antibiotics which affect protein, DNA, RNA, and cell wall synthesis no longer yield soluble LPS following treatment with the releasing agents. On the other hand, bacteria which are resistant to certain of the antibiotics yield nearly the full amount of soluble LPS following treatment, suggesting that certain heatabile endogenous metabolic pathways collaborate with the releasing agents in the release of LPS from the bacteria. It is suggested that some of the beneficial effects of antibiotics on infections with gram-negative bacteria may be the prevention of massive release of endotoxin by leukocyte enzymes in inflammatory sites

  10. Systemic resistance induced by rhizosphere bacteria

    NARCIS (Netherlands)

    Loon, L.C. van; Bakker, P.A.H.M.; Pieterse, C.M.J.


    Nonpathogenic rhizobacteria can induce a systemic resistance in plants that is phenotypically similar to pathogen-induced systemic acquired resistance (SAR). Rhizobacteria-mediated induced systemic resistance (ISR) has been demonstrated against fungi, bacteria, and viruses in Arabidopsis, bean,

  11. Lactic acid bacteria: microbiological and functional aspects

    National Research Council Canada - National Science Library

    Lahtinen, Sampo


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

  12. Comparative genomics of the lactic acid bacteria

    Energy Technology Data Exchange (ETDEWEB)

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


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

  13. Do bacteria, not fish, produce 'fish kairomone'?

    NARCIS (Netherlands)

    Ringelberg, J.; Van Gool, E.


    Fish-associated chemicals enhance phototactic downward swimming in Daphnia. If perch were treated with the antibiotic ampicillin, this enhancement was significantly decreased. Therefore, not fish, but bacteria associated with fish, seem to produce this kairomone. [KEYWORDS: Diel vertical migration;

  14. Bacteria-mediated bisphenol A degradation. (United States)

    Zhang, Weiwei; Yin, Kun; Chen, Lingxin


    Bisphenol A (BPA) is an important monomer in the manufacture of polycarbonate plastics, food cans, and other daily used chemicals. Daily and worldwide usage of BPA and BPA-contained products led to its ubiquitous distribution in water, sediment/soil, and atmosphere. Moreover, BPA has been identified as an environmental endocrine disruptor for its estrogenic and genotoxic activity. Thus, BPA contamination in the environment is an increasingly worldwide concern, and methods to efficiently remove BPA from the environment are urgently recommended. Although many factors affect the fate of BPA in the environment, BPA degradation is mainly depended on the metabolism of bacteria. Many BPA-degrading bacteria have been identified from water, sediment/soil, and wastewater treatment plants. Metabolic pathways of BPA degradation in specific bacterial strains were proposed, based on the metabolic intermediates detected during the degradation process. In this review, the BPA-degrading bacteria were summarized, and the (proposed) BPA degradation pathway mediated by bacteria were referred.

  15. Abundance, viability and culturability of Antarctic bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; DeSouza, M.J.B.D.; Nair, S.; Chandramohan, D.

    The viability of total number of bacteria decide the mineralisation rate in any ecosystem and ultimately the fertility of the region. This study aims at establishing the extent of viability in the standing stock of the Antarctic bacterial population...

  16. Interactions between phototrophic bacteria in marine sediments

    NARCIS (Netherlands)

    de Wit, Rutger


    Phototrophic bacteria are the most consicious organisms occuring in laminated microbial sediment ecosystems (microbial mats). In the Waddensea area ecosystems consisting of a toplayer of the cyanobacterium Microleus chthonoplastes overlying a red layer of the purple sulfur bacterium Thiocapsa

  17. Molecular genetic studies on obligate anaerobic bacteria

    International Nuclear Information System (INIS)

    Woods, D.R.


    Molecular genetic studies on obligate anaerobic bacteria have lagged behind similar studies in aerobes. However, the current interest in biotechnology, the involvement of anaerobes in disease and the emergence of antibioticresistant strains have focused attention on the genetics of anaerobes. This article reviews molecular genetic studies in Bacteroides spp., Clostridium spp. and methanogens. Certain genetic systems in some anaerobes differ from those in aerobes and illustrate the genetic diversity among bacteria

  18. Ecology: Electrical Cable Bacteria Save Marine Life

    DEFF Research Database (Denmark)

    Nielsen, Lars Peter


    Animals at the bottom of the sea survive oxygen depletion surprisingly often, and a new study identifies cable bacteria in the sediment as the saviors. The bacterial electrical activity creates an iron 'carpet', trapping toxic hydrogen sulfide.......Animals at the bottom of the sea survive oxygen depletion surprisingly often, and a new study identifies cable bacteria in the sediment as the saviors. The bacterial electrical activity creates an iron 'carpet', trapping toxic hydrogen sulfide....

  19. Extracellular deoxyribonuclease production by periodontal bacteria. (United States)

    Palmer, L J; Chapple, I L C; Wright, H J; Roberts, A; Cooper, P R


    Whilst certain bacteria have long been known to secrete extracellular deoxyribonuclease (DNase), the purpose in microbial physiology was unclear. Recently, however, this enzyme has been demonstrated to confer enhanced virulence, enabling bacteria to evade the host's immune defence of extruded DNA/chromatin filaments, termed neutrophil extracellular traps (NETs). As NETs have recently been identified in infected periodontal tissue, the aim of this study was to screen periodontal bacteria for extracellular DNase activity. To determine whether DNase activity was membrane bound or secreted, 34 periodontal bacteria were cultured in broth and on agar plates. Pelleted bacteria and supernatants from broth cultures were analysed for their ability to degrade DNA, with relative activity levels determined using an agarose gel electrophoresis assay. Following culture on DNA-supplemented agar, expression was determined by the presence of a zone of hydrolysis and DNase activity related to colony size. Twenty-seven bacteria, including red and orange complex members Porphyromonas gingivalis, Tannerella forsythia, Fusobacterium nucleatum, Parvimonas micra, Prevotella intermedia, Streptococcus constellatus, Campylobacter rectus and Prevotella nigrescens, were observed to express extracellular DNase activity. Differences in DNase activity were noted, however, when bacteria were assayed in different culture states. Analysis of the activity of secreted DNase from bacterial broth cultures confirmed their ability to degrade NETs. The present study demonstrates, for the first time, that DNase activity is a relatively common property of bacteria associated with advanced periodontal disease. Further work is required to determine the importance of this bacterial DNase activity in the pathogenesis of periodontitis. © 2011 John Wiley & Sons A/S.

  20. Occurrence of diazotrophic bacteria in Araucaria angustifolia


    Neroni,Rafaela de Fátima; Cardoso,Elke Jurandy Bran Nogueira


    Araucaria angustifolia is an environmentally threatened tree and the whole biota of the Araucaria Forest should be investigated with the aim of its preservation. Diazotrophic bacteria are extremely important for the maintenance of ecosystems, but they have never been studied in Araucaria Forests. In this study, diazotrophic bacteria were isolated from Araucaria roots and soil, when grown in semi-specific, semi-solid media. The diazotrophic character of some recovered isolates could be confirm...

  1. [Teichoic acids from lactic acid bacteria]. (United States)

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


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

  2. Mimicking Seawater For Culturing Marine Bacteria

    DEFF Research Database (Denmark)

    Rygaard, Anita Mac; Sonnenschein, Eva; Gram, Lone


    Only about 1% of marine bacteria have been brought into culture using traditional techniques. The purpose of this study was to investigate if mimicking the natural bacterial environment can increase culturability.We used marine substrates containing defined algal polymers or gellan gum as solidif......Only about 1% of marine bacteria have been brought into culture using traditional techniques. The purpose of this study was to investigate if mimicking the natural bacterial environment can increase culturability.We used marine substrates containing defined algal polymers or gellan gum...... as solidifying agents, and enumerated bacteria from seawater and algal exudates. We tested if culturability could be influenced by addition of quorum sensing signals (AHLs). All plates were incubated at 15°C. Bacterial counts (CFU/g) from algal exudates from brown algae were highest on media containing algal...... polymers. In general, bacteria isolated from algal exudates preferred more rich media than bacteria isolated from seawater. Overall, culturability ranged from 0.01 to 0.8% as compared to total cell count. Substitution of agar with gellan gum increased the culturability of seawater bacteria approximately...

  3. Antibiotic-resistant bacteria in drinking water. (United States)

    Armstrong, J L; Shigeno, D S; Calomiris, J J; Seidler, R J


    We analyzed drinking water from seven communities for multiply antibiotic-resistant (MAR) bacteria (bacteria resistant to two or more antibiotics) and screened the MAR bacterial isolates obtained against five antibiotics by replica plating. Overall, 33.9% of 2,653 standard plate count bacteria from treated drinking waters were MAR. Two different raw water supplies for two communities carried MAR standard plate count bacteria at frequencies of 20.4 and 18.6%, whereas 36.7 and 67.8% of the standard plate count populations from sites within the respective distribution systems were MAR. Isolate identification revealed that MAR gram-positive cocci (Staphylococcus) and MAR gram-negative, nonfermentative rods (Pseudomonas, Alcaligenes, Moraxella-like group M, and Acinetobacter) were more common in drinking waters than in untreated source waters. Site-to-site variations in generic types and differences in the incidences of MAR organisms indicated that shedding of MAR bacteria living in pipelines may have contributed to the MAR populations in tap water. We conclude that the treatment of raw water and its subsequent distribution select for standard plate count bacteria exhibiting the MAR phenotype.

  4. Isolation and characterization of two plant growth-promoting bacteria from the rhizoplane of a legume (Lupinus albescens in sandy soil Isolamento e caracterização de duas bactérias promotoras de crescimento vegetal do rizoplano de uma leguminosa (Lupinus albescens de solo arenoso

    Directory of Open Access Journals (Sweden)

    Adriana Giongo


    Full Text Available Two bacterial strains that amplified part of the nifH gene, RP1p and RP2p, belonging to the genus Enterobacter and Serratia, were isolated from the rhizoplane of Lupinus albescens. These bacteria are Gram-negative, rod-shaped, motile, facultative anaerobic, and fast-growing; the colonies reach diameters of 3-4 mm within 24 h of incubation at 28 ºC. The bacteria were also able to grow at temperatures as high as 40 ºC, in the presence of high (2-3 % w/v NaCl concentrations and pH 4 -10. Strain RP1p was able to utilize 10 of 14 C sources, while RP2p utilized nine. The isolates produced siderophores and indolic compounds, but none of them was able to solubilize phosphate. Inoculation of L. albescens with RP1p and RP2p strains resulted in a significant increase in plant dry matter, indicating the plant-growth-promoting abilities of these bacteria.Duas linhagens bacterianas que apresentaram amplificação de parte do gene nifH, RP1p e RP2p, pertencentes aos gêneros Enterobacter e Serratia, foram isoladas do rizoplano de Lupinus albescens. Essas bactérias são Gram-negativas, com formato de bastonete, móveis, anaeróbias facultativas e apresentam multiplicação rápida, com colônias alcançando diâmetros de 3-4 mm em 24 h de incubação a 28 ºC. RP1p e RP2p também foram capazes de multiplicação em temperaturas elevadas, como 40 ºC, na presença de alta concentração de NaCl (2-3 % v/v e em valores de pH que variaram de 4 a 10. A linhagem RP1p foi capaz de utilizar 10 das 14 fontes de carbono avaliadas, enquanto a linhagem RP2p utilizou nove. Os isolados produziram sideróforos e compostos indólicos, mas foram incapazes de solubilizar fosfatos. A inoculação de L. albescens com as linhagens RP1p e RP2p resultou em aumento significativo do peso das plantas secas, o que demonstra que essas bactérias apresentam propriedades que favorecem o crescimento vegetal.

  5. Nanotextile membranes for bacteria Escherichia coli capturing

    Directory of Open Access Journals (Sweden)

    Jaroslav Lev


    Full Text Available The article describes an experimental study dealing with the possibility of nanotextile materials usa­ge for microbiologically contaminated water filtration. The aim of the study is to verify filtration ability of different nanotextile materials and evaluate the possibilities of practical usage. Good detention ability of these materials in the air filtration is the presumption for nanotextile to be used for bacteria filtration from a liquid. High nanotextile porosity with the nanotextile pores dimensions smaller than a bacteria size predicates the possibility of a successful usage of these materials. For the experiment were used materials made from electrospinning nanofibres under the label PA612, PUR1, PUR2 s PUR3 on the supporting unwoven textiles (viscose and PP. As a model simulation of the microbial contamination, bacteria Escherichia coli was chosen. Contaminated water was filtered during the overpressure activity of 105Pa on the input side of the filter from the mentioned material. After three-day incubation on the nutrient medium, cultures found in the samples before and after filtration were compared. In the filtrated water, bacteria E. coli were indicated, which did not verify the theoretical presumptions about an absolut bacteria detention. However, used materials caught at least 94% of bacteria in case of material PUR1 and up to 99,996% in case of material PUR2. These results predict the possibility of producing effective nanotextile filters for microbiologically contaminated water filtration.Recommendation: For the production of materials with better filtrating qualities, experiments need to be done, enabling better understanding of the bacteria detention mechanisms on the nanotextile material, and parameters of the used materials that influence the filtrating abilities need to be verified.

  6. [Spectrum and susceptibility of preoperative conjunctival bacteria]. (United States)

    Fernández-Rubio, M E; Cuesta-Rodríguez, T; Urcelay-Segura, J L; Cortés-Valdés, C


    To describe the conjunctival bacterial spectrum of our patients undergoing intraocular surgery and their antibiotic sensitivity during the study period. A retrospective study of preoperative conjunctival culture of patients consecutively scheduled for intraocular surgery from 21 February 2011 to 1 April 2013. Specimens were directly seeded onto blood-agar and MacConkey-agar (aerobiosis incubation, 2 days), and on chocolate-agar (6% CO2 incubation, 7 days). The identified bacteria were divided into 3 groups according to their origin; the bacteria susceptibility tests were performed on those more pathogenic and on some of the less pathogenic when more than 5 colonies were isolated. The sensitivity of the exigent growing bacteria was obtained with disk diffusion technique, and for of the non-exigent bacteria by determining their minimum inhibitory concentration. The Epidat 3.1 program was used for statistical calculations. A total of 13,203 bacteria were identified in 6,051 cultures, with 88.7% being typical colonizers of conjunctiva (group 1), 8.8% typical of airways (group 2), and the remaining 2.5% of undetermined origin (group 3). 530 cultures (8.8%) were sterile. The sensitivity of group 1 was: 99% vancomycin, 95% rifampicin, 87% chloramphenicol, 76% tetracycline. Levels of co-trimoxazole, aminoglycosides, quinolones, β-lactams and macrolides decreased since 2007. The group 2 was very sensitive to chloramphenicol, cefuroxime, rifampicin, ciprofloxacin and amoxicillin/clavulanate. In group 3, to levofloxacin 93%, ciprofloxacin 89%, tobramycin 76%, but ceftazidime 53% and cefuroxime 29% decreased. None of the tested antibiotics could eradicate all possible conjunctival bacteria. Bacteria living permanently on the conjunctiva (group 1) have achieved higher resistance than the eventual colonizers. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

  7. Magnetosome chain superstructure in uncultured magnetotactic bacteria

    International Nuclear Information System (INIS)

    Abraçado, Leida G; Farina, Marcos; Abreu, Fernanda; Keim, Carolina N; Lins, Ulysses; Campos, Andrea P C


    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

  8. Chemically enhanced sunlight for killing bacteria

    International Nuclear Information System (INIS)

    Block, S.S.; Goswami, D.Y.


    Solar ultraviolet (UV) photocatalyzed oxidation of chemicals with titanium dioxide (TiO 2 ) has received considerable attention. Much less recognized, however, is the ability of the same system to destroy bacteria. This study examined this phenomenon and the conditions that affect it. Bacteria in aqueous solution were given solar exposure with titanium dioxide and their survival with time was determined. Lamps with a predominantly solar ultraviolet spectrum were also used in the experiments. Without exposure to UV light, TiO 2 had no deleterious effect on the bacteria. However, several common bacteria on solar exposure in the presence of TiO 2 were killed in just a few minutes, whereas without TiO 2 it took over an hour to destroy them. A concentration of 0.01% TiO 2 was most effective in killing bacteria and 10-fold concentrations lower or higher were successively less effective. Inorganic and organic compounds in solution, even in small amounts, interfered with the efficiency of killing. Alkaline solution also reduced the bactericidal activity. Circulation and agitation provided by stirring to keep the TiO 2 particles suspended reduced the time necessary to kill the bacteria. Time-intensity curves for killing bacteria were the same general shape with or without TiO 2 , indicating that TiO 2 served merely as a catalyst to increase the rate of the reaction but that the mechanism of action was not changed. The shape of the curves show that the organisms are sensitized with a minimum intensity of radiation and that an increase doesn't greatly increase the rate of kill. Below this critical intensity, however, the time required for killing markedly increases as the intensity is decreased

  9. Using Bacteria to Store Renewable Energy (Text Version) | News | NREL (United States)

    Using Bacteria to Store Renewable Energy (Text Version) Using Bacteria to Store Renewable Energy is a text version of the video entitled "Using Bacteria to Store Renewable Energy." ; Bacteria from some of the Earth's harshest environments now have a new home at NREL. [A natural spring has

  10. Rapid diagnostics of the bacteria in air

    Energy Technology Data Exchange (ETDEWEB)

    Belov Nikolai, N. [ATECH KFT, Budapest (Hungary)


    Presence of the bacteria and viruses in the air is great problem now. Terrorists are going to use the bacteria weapon. Now biotechnology provides very cheap equipment ({approx} $500) for modification of the bacteria sorts. It may be used for receiving of new variants of the bacteriological weapon. And presence of one small bacteria aerosol generator in the international airport during several days will start the dangerous epidemic incidence the entire world. From another side - poor countries with hot and wet weather are continuously producing new and new dangerous bacteria. Every year epidemic waves of influence are going from China, India or Africa. And once up a time it will be epidemic explosive with fast lethal finish. Methods of estimation of the bio-aerosols in Air of City are very poor. Standard Bio-aerosol sampler has two conflicting demands. From one side the bio-sampler needs in great air volume of sample with great efficiency of separation of aerosol particles from measured air. From another side all selected particles needs in great care. This demand carried out from method of measurement of bacteria in sample by counting of colonies that grew from bacteria on nutrient media after incubation time. It is a problem to prevent bacterial flora from death during collecting aerosol sample. This time of growth and counting of colony is so long that result of this measurement will be unusable if it will be terrorist action of start of bacteriological was. Here presented new methods for fast diagnostics of the bacteria in the air. It consists from 4 general parts: (1) Micro-droplet method for diagnostics of biological active substances in aerosol sample. This method allows to control the bio-particle position on the plate, to use series of biochemistry species for analytical reaction for this small bio-particle. Small volume of biochemical reaction reduces noise. This method provides extremely high sensitivity for discovering of biological material. (2

  11. Modulation of immune homeostasis by commensal bacteria (United States)

    Ivanov, Ivaylo I.; Littman, Dan R.


    Intestinal bacteria form a resident community that has co-evolved with the mammalian host. In addition to playing important roles in digestion and harvesting energy, commensal bacteria are crucial for the proper functioning of mucosal immune defenses. Most of these functions have been attributed to the presence of large numbers of “innocuous” resident bacteria that dilute or occupy niches for intestinal pathogens or induce innate immune responses that sequester bacteria in the lumen, thus quenching excessive activation of the mucosal immune system. However it has recently become obvious that commensal bacteria are not simply beneficial bystanders, but are important modulators of intestinal immune homeostasis and that the composition of the microbiota is a major factor in pre-determining the type and robustness of mucosal immune responses. Here we review specific examples of individual members of the microbiota that modify innate and adaptive immune responses, and we focus on potential mechanisms by which such species-specific signals are generated and transmitted to the host immune system. PMID:21215684

  12. Molecular analysis of deep subsurface bacteria

    International Nuclear Information System (INIS)

    Jimenez Baez, L.E.


    Deep sediments samples from site C10a, in Appleton, and sites, P24, P28, and P29, at the Savannah River Site (SRS), near Aiken, South Carolina were studied to determine their microbial community composition, DNA homology and mol %G+C. Different geological formations with great variability in hydrogeological parameters were found across the depth profile. Phenotypic identification of deep subsurface bacteria underestimated the bacterial diversity at the three SRS sites, since bacteria with the same phenotype have different DNA composition and less than 70% DNA homology. Total DNA hybridization and mol %G+C analysis of deep sediment bacterial isolates suggested that each formation is comprised of different microbial communities. Depositional environment was more important than site and geological formation on the DNA relatedness between deep subsurface bacteria, since more 70% of bacteria with 20% or more of DNA homology came from the same depositional environments. Based on phenotypic and genotypic tests Pseudomonas spp. and Acinetobacter spp.-like bacteria were identified in 85 million years old sediments. This suggests that these microbial communities might have been adapted during a long period of time to the environmental conditions of the deep subsurface

  13. Overlapping riboflavin supply pathways in bacteria. (United States)

    García-Angulo, Víctor Antonio


    Riboflavin derivatives are essential cofactors for a myriad of flavoproteins. In bacteria, flavins importance extends beyond their role as intracellular protein cofactors, as secreted flavins are a key metabolite in a variety of physiological processes. Bacteria obtain riboflavin through the endogenous riboflavin biosynthetic pathway (RBP) or by the use of importer proteins. Bacteria frequently encode multiple paralogs of the RBP enzymes and as for other micronutrient supply pathways, biosynthesis and uptake functions largely coexist. It is proposed that bacteria shut down biosynthesis and would rather uptake riboflavin when the vitamin is environmentally available. Recently, the overlap of riboflavin provisioning elements has gained attention and the functions of duplicated paralogs of RBP enzymes started to be addressed. Results point towards the existence of a modular structure in the bacterial riboflavin supply pathways. Such structure uses subsets of RBP genes to supply riboflavin for specific functions. Given the importance of riboflavin in intra and extracellular bacterial physiology, this complex array of riboflavin provision pathways may have developed to contend with the various riboflavin requirements. In riboflavin-prototrophic bacteria, riboflavin transporters could represent a module for riboflavin provision for particular, yet unidentified processes, rather than substituting for the RBP as usually assumed.

  14. Bacteria and plutonium in marine environments

    International Nuclear Information System (INIS)

    Carey, A.E.; Bowen, V.T.


    Microbes are important in geochemical cycling of many elements. Recent reports emphasize biogenous particulates and bacterial exometabolites as controlling oceanic distribution of plutonium. Bacteria perform oxidation/reduction reactions on metals such as mercury, nickel, lead, copper, and cadmium. Redox transformations or uptake of Pu by marine bacteria may well proceed by similar mechanisms. Profiles of water samples and sediment cores were obtained along the continental shelf off Nova Scotia and in the Gulf of St. Lawrence. Profiles of water samples, and sediment cores were obtained. Epifluorescent microscopy was used to view bacteria (from water or sediment) after concentration on membrane filters and staining with acridine orange. Radiochemical analyses measured Pu in sediments and water samples. Studies of 237 Pu uptake used a strain of Leucothrix mucor isolated from a macroalga. Enumeration shows bacteria to range 10 4 to 10 5 cells/ml in seawater or 10 7 to 10 8 cells/gram of sediment. These numbers are related to the levels and distrbution of Pu in the samples. In cultures of L. mucor amended with Pu atom concentrations approximating those present in open ocean environments, bacterial cells concentrated 237 Pu slower and to lower levels than did clay minerals, glass beads, or phytoplankton. These data further clarify the role of marine bacteria in Pu biogeochemistry

  15. Method of Detecting Coliform Bacteria and Escherichia Coli Bacteria from Reflected Light (United States)

    Vincent, Robert (Inventor)


    The present invention relates to a method of detecting coliform bacteria in water from reflected light and a method of detecting Eschericha Coli bacteria in water from reflected light, and also includes devices for the measurement, calculation and transmission of data relating to that method.


    NARCIS (Netherlands)


    The populations of chemolithoautotrophic (colorless) sulfur bacteria and anoxygenic phototrophic bacteria were enumerated in a marine microbial mat. The highest population densities were found in the 0-5 mm layer of the mat: 2.0 X 10(9) cells CM-3 sediment, and 4.0 X 10(7) cells cm-3 sediment for

  17. Using Fluorescent Viruses for Detecting Bacteria in Water (United States)

    Tabacco, Mary Beth; Qian, Xiaohua; Russo, Jaimie A.


    A method of detecting water-borne pathogenic bacteria is based partly on established molecular-recognition and fluorescent-labeling concepts, according to which bacteria of a species of interest are labeled with fluorescent reporter molecules and the bacteria can then be detected by fluorescence spectroscopy. The novelty of the present method lies in the use of bacteriophages (viruses that infect bacteria) to deliver the fluorescent reporter molecules to the bacteria of the species of interest.

  18. Effects of ionizing radiation on bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Suhadi, F [National Atomic Energy Agency, Jakarta (Indonesia). Pasar Djumat Research Centre


    The differences of radiosensitivities among bacteria in addition to the dependence upon the species or strains also depends on the environmental condition during irradiation (temperature, medium, the presence of protective or sensitizing agents, the gas phase or atmosphere, and water activity, or degree of hydration) and on the effects of the environmental condition before and after irradiation treatment (temperature of incubation, age of culture and growth medium). In general, spores are more resistant to radiation than vegetatic bacteria, with the exception that a few cocci are the most radiation resistant bacteria (Micrococcus and Streptococcus). The application of ionizing radiation in the fields of microbiology supports the radiation sterilization of medical and pharmaceutical products. In addition, microbiological aspects of food preservation, especially radurization, radicidation, and immunization studies by using irradiated microorganisms, are also important.

  19. Threats and opportunities of plant pathogenic bacteria. (United States)

    Tarkowski, Petr; Vereecke, Danny


    Plant pathogenic bacteria can have devastating effects on plant productivity and yield. Nevertheless, because these often soil-dwelling bacteria have evolved to interact with eukaryotes, they generally exhibit a strong adaptivity, a versatile metabolism, and ingenious mechanisms tailored to modify the development of their hosts. Consequently, besides being a threat for agricultural practices, phytopathogens may also represent opportunities for plant production or be useful for specific biotechnological applications. Here, we illustrate this idea by reviewing the pathogenic strategies and the (potential) uses of five very different (hemi)biotrophic plant pathogenic bacteria: Agrobacterium tumefaciens, A. rhizogenes, Rhodococcus fascians, scab-inducing Streptomyces spp., and Pseudomonas syringae. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Hydrodynamic interaction between bacteria and passive sphere (United States)

    Zhang, Bokai; Ding, Yang; Xu, Xinliang


    Understanding hydrodynamic interaction between bacteria and passive sphere is important for identifying rheological properties of bacterial and colloidal suspension. Over the past few years, scientists mainly focused on bacterial influences on tracer particle diffusion or hydrodynamic capture of a bacteria around stationary boundary. Here, we use superposition of singularities and regularized method to study changes in bacterial swimming velocity and passive sphere diffusion, simultaneously. On this basis, we present a simple two-bead model that gives a unified interpretation of passive sphere diffusion and bacterial swimming. The model attributes both variation of passive sphere diffusion and changes of speed of bacteria to an effective mobility. Using the effective mobility of bacterial head and tail as an input function, the calculations are consistent with simulation results at a broad range of tracer diameters, incident angles and bacterial shapes.

  1. Interactions among sulfide-oxidizing bacteria (United States)

    Poplawski, R.


    The responses of different phototrophic bacteria in a competitive experimental system are studied, one in which primary factors such as H2S or light limited photometabolism. Two different types of bacteria shared one limited source of sulfide under specific conditions of light. The selection of a purple and a green sulfur bacteria and the cyanobacterium was based on their physiological similarity and also on the fact that they occur together in microbial mats. They all share anoxygenic photosynthesis, and are thus probably part of an evolutionary continuum of phototrophic organisms that runs from, strictly anaerobic physiology to the ability of some cyanobacteria to shift between anoxygenic bacterial style photosynthesis and the oxygenic kind typical of eukaryotes.

  2. Copper tolerance and virulence in bacteria (United States)

    Ladomersky, Erik; Petris, Michael J.


    Copper (Cu) is an essential trace element for all aerobic organisms. It functions as a cofactor in enzymes that catalyze a wide variety of redox reactions due to its ability to cycle between two oxidation states, Cu(I) and Cu(II). This same redox property of copper has the potential to cause toxicity if copper homeostasis is not maintained. Studies suggest that the toxic properties of copper are harnessed by the innate immune system of the host to kill bacteria. To counter such defenses, bacteria rely on copper tolerance genes for virulence within the host. These discoveries suggest bacterial copper intoxication is a component of host nutritional immunity, thus expanding our knowledge of the roles of copper in biology. This review summarizes our current understanding of copper tolerance in bacteria, and the extent to which these pathways contribute to bacterial virulence within the host. PMID:25652326

  3. Lethal photosensitization of biofilm-grown bacteria (United States)

    Wilson, Michael


    Antibacterial agents are increasingly being used for the prophylaxis and treatment of oral diseases. As these agents can be rendered ineffective by resistance development in the target organisms there is a need to develop alternative antimicrobial approaches. Light-activated antimicrobial agents release singlet oxygen and free radicals which can kill adjacent bacteria and a wide range of cariogenic and periodontopathogenic bacteria has been shown to be susceptible to such agents. In the oral cavity these organisms are present as biofilms (dental plaques) which are less susceptible to traditional antimicrobial agents than bacterial suspensions. The results of these studies have shown that biofilm-grown oral bacteria are also susceptible to lethal photosensitization although the light energy doses required are grater than those needed to kill the organisms when they are grown as aqueous suspensions.

  4. Gastric spiral bacteria in small felids. (United States)

    Kinsel, M J; Kovarik, P; Murnane, R D


    Nine small cats, including one bobcat (Felis rufus), one Pallas cat (F. manul), one Canada lynx (F. lynx canadensis), two fishing cats (F. viverrina), two margays (F. wiedii), and two sand cats (F. margarita), necropsied between June 1995 and March 1997 had large numbers of gastric spiral bacteria, whereas five large cats, including one African lion (Panthera leo), two snow leopards (P. uncia), one Siberian tiger (P. tigris altaica), and one jaguar (P. onca), necropsied during the same period had none. All of the spiral organisms from the nine small cats were histologically and ultrastructurally similar. Histologically, the spiral bacteria were 5-14 microm long with five to nine coils per organism and were located both extracellularly within gastric glands and surface mucus, and intracellularly in parietal cells. Spiral bacteria in gastric mucosal scrapings from the Canada lynx, one fishing cat, and the two sand cats were gram negative and had corkscrewlike to tumbling motility when viewed with phase contrast microscopy. The bacteria were 0.5-0.7 microm wide, with a periodicity of 0.65-1.1 microm in all cats. Bipolar sheathed flagella were occasionally observed, and no periplasmic fibrils were seen. The bacteria were extracellular in parietal cell canaliculi and intracellular within parietal cells. Culture of mucosal scrapings from the Canada lynx and sand cats was unsuccessful. Based on morphology, motility, and cellular tropism, the bacteria were probably Helicobacter-like organisms. Although the two margays had moderate lymphoplasmacytic gastritis, the other cats lacked or had only mild gastric lymphoid infiltrates, suggesting that these organisms are either commensals or opportunistic pathogens.

  5. Exogenous fatty acid metabolism in bacteria. (United States)

    Yao, Jiangwei; Rock, Charles O


    Bacterial type II fatty acid synthesis (FASII) is a target for novel antibiotic development. All bacteria encode for mechanisms to incorporate exogenous fatty acids, and some bacteria can use exogenous fatty acids to bypass FASII inhibition. Bacteria encode three different mechanisms for activating exogenous fatty acids for incorporation into phospholipid synthesis. Exogenous fatty acids are converted into acyl-CoA in Gammaproteobacteria such as E. coli. Acyl-CoA molecules constitute a separate pool from endogenously synthesized acyl-ACP. Acyl-CoA can be used for phospholipid synthesis or broken down by β-oxidation, but cannot be used for lipopolysaccharide synthesis. Exogenous fatty acids are converted into acyl-ACP in some Gram-negative bacteria. The resulting acyl-ACP undergoes the same fates as endogenously synthesized acyl-ACP. Exogenous fatty acids are converted into acyl-phosphates in Gram-positive bacteria, and can be used for phospholipid synthesis or become acyl-ACP. Only the order Lactobacillales can use exogenous fatty acids to bypass FASII inhibition. FASII shuts down completely in presence of exogenous fatty acids in Lactobacillales, allowing Lactobacillales to synthesize phospholipids entirely from exogenous fatty acids. Inhibition of FASII cannot be bypassed in other bacteria because FASII is only partially down-regulated in presence of exogenous fatty acid or FASII is required to synthesize essential metabolites such as β-hydroxyacyl-ACP. Certain selective pressures such as FASII inhibition or growth in biofilms can select for naturally occurring one step mutations that attenuate endogenous fatty acid synthesis. Although attempts have been made to estimate the natural prevalence of these mutants, culture-independent metagenomic methods would provide a better estimate. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  6. Differential staining of bacteria: gram stain. (United States)

    Moyes, Rita B; Reynolds, Jackie; Breakwell, Donald P


    In 1884, Hans Christian Gram, a Danish doctor, developed a differential staining technique that is still the cornerstone of bacterial identification and taxonomic division. This multistep, sequential staining protocol separates bacteria into four groups based on cell morphology and cell wall structure: Gram-positive cocci, Gram-negative cocci, Gram-positive rods, and Gram-negative rods. The Gram stain is useful for assessing bacterial contamination of tissue culture samples or for examining the Gram stain status and morphological features of bacteria isolated from mixed or isolated bacterial cultures. (c) 2009 by John Wiley & Sons, Inc.

  7. Motile bacteria in a critical fluid mixture (United States)

    Koumakis, Nick; Devailly, Clémence; Poon, Wilson C. K.


    We studied the swimming of Escherichia coli bacteria in the vicinity of the critical point in a solution of the nonionic surfactant C12E5 in buffer solution. In phase-contrast microscopy, each swimming cell produces a transient trail behind itself lasting several seconds. Comparing quantitative image analysis with simulations show that these trails are due to local phase reorganization triggered by differential adsorption. This contrasts with similar trails seen in bacteria swimming in liquid crystals, which are due to shear effects. We show how our trails are controlled, and use them to probe the structure and dynamics of critical fluctuations in the fluid medium.

  8. Bacteria Provide Cleanup of Oil Spills, Wastewater (United States)


    Through Small Business Innovation Research (SBIR) contracts with Marshall Space Flight Center, Micro-Bac International Inc., of Round Rock, Texas, developed a phototrophic cell for water purification in space. Inside the cell: millions of photosynthetic bacteria. Micro-Bac proceeded to commercialize the bacterial formulation it developed for the SBIR project. The formulation is now used for the remediation of wastewater systems and waste from livestock farms and food manufacturers. Strains of the SBIR-derived bacteria also feature in microbial solutions that treat environmentally damaging oil spills, such as that resulting from the catastrophic 2010 Deepwater Horizon oil rig explosion in the Gulf of Mexico.

  9. Functional Encyclopedia of Bacteria and Archaea

    Energy Technology Data Exchange (ETDEWEB)

    Blow, M. J.; Deutschbauer, A. M.; Hoover, C. A.; Lamson, J.; Lamson, J.; Price, M. N.; Waters, J.; Wetmore, K. M.; Bristow, J.; Arkin, A. P.


    Bacteria and Archaea exhibit a huge diversity of metabolic capabilities with fundamental importance in the environment, and potential applications in biotechnology. However, the genetic bases of these capabilities remain unclear due largely to an absence of technologies that link DNA sequence to molecular function. To address this challenge, we are developing a pipeline for high throughput annotation of gene function using mutagenesis, growth assays and DNA sequencing. By applying this pipeline to annotate gene function in 50 diverse microbes we hope to discover thousands of new gene functions and produce a proof of principle `Functional Encyclopedia of Bacteria and Archaea?.

  10. Beer spoilage bacteria and hop resistance. (United States)

    Sakamoto, Kanta; Konings, Wil N


    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 Megasphaera cerevisiae. They can spoil beer by turbidity, acidity and the production of unfavorable smell such as diacetyl or hydrogen sulfide. For the microbiological control, many advanced biotechnological techniques such as immunoassay and polymerase chain reaction (PCR) have been applied in place of the conventional and time-consuming method of incubation on culture media. Subsequently, a method is needed to determine whether the detected bacterium is capable of growing in beer or not. In lactic acid bacteria, hop resistance is crucial for their ability to grow in beer. Hop compounds, mainly iso-alpha-acids in beer, have antibacterial activity against Gram-positive bacteria. They act as ionophores which dissipate the pH gradient across the cytoplasmic membrane and reduce the proton motive force (pmf). Consequently, the pmf-dependent nutrient uptake is hampered, resulting in cell death. The hop-resistance mechanisms in lactic acid bacteria have been investigated. HorA was found to excrete hop compounds in an ATP-dependent manner from the cell membrane to outer medium. Additionally, increased proton pumping by the membrane bound H(+)-ATPase contributes to hop resistance. To energize such ATP-dependent transporters hop-resistant cells contain larger ATP pools than hop-sensitive cells. Furthermore, a pmf-dependent hop transporter was recently presented. Understanding the hop-resistance mechanisms has enabled the development of rapid methods to discriminate beer spoilage strains from nonspoilers. The horA-PCR method has been applied for bacterial control in breweries. Also, a discrimination method was developed based on ATP pool measurement in lactobacillus cells. However

  11. Pathogenic Assay of Probiotic Bacteria Producing Proteolytic Enzymes as Bioremediation Bacteria Against Vannamei Shrimp Larvae (Litopenaeus vannamei)


    Wilis Ari Setyati; Muhammad Zainuddin; Person Pesona Renta


    Application of bacteria in bioremediation of shrimp culture ponds is one of the methods used to clean internal pollutants. This study aimed to evaluate the pathogenicity of extracellular proteolytic enzyme produced by the probiotic bacteria as bioremediation bacteria on vannamei shrimp larvae culture. There were five probiotic bacteria, which were successfully isolated from the sediments served as substrate in mangrove area. The isolated bacteria were coded in number as 13, 19, 30, 33, and 36...

  12. Effects of symbiotic bacteria on chemical sensitivity of Daphnia magna. (United States)

    Manakul, Patcharaporn; Peerakietkhajorn, Saranya; Matsuura, Tomoaki; Kato, Yasuhiko; Watanabe, Hajime


    The crustacean zooplankton Daphnia magna has been widely used for chemical toxicity tests. Although abiotic factors have been well documented in ecotoxicological test protocols, biotic factors that may affect the sensitivity to chemical compounds remain limited. Recently, we identified symbiotic bacteria that are critical for the growth and reproduction of D. magna. The presence of symbiotic bacteria on Daphnia raised the question as to whether these bacteria have a positive or negative effect on toxicity tests. In order to evaluate the effects of symbiotic bacteria on toxicity tests, bacteria-free Daphnia were prepared, and their chemical sensitivities were compared with that of Daphnia with symbiotic bacteria based on an acute immobilization test. The Daphnia with symbiotic bacteria showed higher chemical resistance to nonylphenol, fenoxycarb, and pentachlorophenol than bacteria-free Daphnia. These results suggested potential roles of symbiotic bacteria in the chemical resistance of its host Daphnia. Copyright © 2017 Elsevier Ltd. All rights reserved.

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


    Bertelsen, Hans; Andersen, Hans; Tvede, Michael


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

  14. Brilliant glyconanocapsules for trapping of bacteria. (United States)

    Yan, Xibo; Sivignon, Adeline; Alcouffe, Pierre; Burdin, Béatrice; Favre-Bonté, Sabine; Bilyy, Rostyslav; Barnich, Nicolas; Fleury, Etienne; Ganachaud, François; Bernard, Julien


    Nanoprecipitation of miglyol into droplets surrounded by a functional glycopolymer generates nanocapsules of biointerest. Fluorophores are trapped in situ or post-grafted onto the crosslinked polymer shell for efficient imaging. The resulting colloids induce aggregation of bacteria through strong specific interactions and promote their facile removal.

  15. Brilliant glyconanocapsules for trapping of bacteria


    Yan, Xibo; Sivignon, Adeline; Alcouffe, Pierre; Burdin, Béatrice; Favre-Bonté, Sabine; Bilyy, Rostyslav; Barnich, Nicolas; Fleury, Etienne; Ganachaud, François; Bernard, Julien


    Nanoprecipitation of miglyol into droplets surrounded by a functional glycopolymer generates nanocapsules of biointerest. Fluorophores are trapped in situ or post-grafted onto the crosslinked polymer shell for efficient imaging. The resulting colloids induce aggregation of bacteria through strong specific interactions and promote their facile removal.

  16. On Bunsen Burners, Bacteria and the Bible

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 2. On Bunsen Burners, Bacteria and the Bible. Milind Watve. Classroom Volume 1 Issue 2 February 1996 pp 84-89. Fulltext. Click here to view fulltext PDF. Permanent link: ...

  17. The effects of bacteria on crystalline rock

    International Nuclear Information System (INIS)

    Brown, D.A.


    Many reactions involving inorganic minerals at water-rock interfaces have now been recognized to be bacterially mediated; these reactions could have a significant effect in the excavation of vaults for toxic and radioactive waste disposal. To investigate the role that bacteria play in the natural aqueous environment of crystalline rock the microbial growth factors of nutrition, energy and environment are described. Microbial activity has been investigated in Atomic Energy of Canada's Underground Research Laboratory (URL), situated in the Archean granitic Lac du Bonnet Batholith, Winnipeg, Manitoba. Faults, initiated in the Early Proterozoic, and later-formed fractures, provide ground-water pathways. Planktonic bacteria, free-swimming in the groundwater, have been observed in over 100 underground borehole samples. The number of bacteria varied from 10 3 to 10 5 mL -1 and appeared to decrease with depth and with increased salinity of the water. However, in the natural environment of deep (100-500 m) crystalline rocks, where nutrition is limited, formation of biofilms by sessile bacteria is a successful survival strategy. Natural biofilms at the URL and biofilms grown in bioreactors have been studied. The biofilms can accumulate different elements, depending upon the local environment. Precipitates of iron have been found in all the biofilms studied, where they are either passively accumulated or utilized as an energy source. Within the biofilm active and extensive biogeochemical immobilization of dissolved elements is controlled by distinct bacterial activities which are sufficiently discrete for hematite and siderite to be precipitated in close proximity

  18. Solvent-tolerant bacteria in biocatalysis.

    NARCIS (Netherlands)

    Bont, de J.A.M.


    The toxicity of fine chemicals to the producer organism is a problem in several biotechnological production processes. In several instances, an organic phase can be used to extract the toxic product from the aqueous phase during a fermentation. With the discovery of solvent-tolerant bacteria, more


    African Journals Online (AJOL)


    With the diminishing rate of natural fish resources globally, a reasonable percentage of fish and fish products .... from these artificial fish habitat, one may not be out of place to ... condition for bacteria reproduction and development in their host ...

  20. Identification of bacteria using mass spectrometry techniques

    Czech Academy of Sciences Publication Activity Database

    Krásný, Lukáš; Hynek, R.; Hochel, I.


    Roč. 353, NOV 2013 (2013), s. 67-79 ISSN 1387-3806 R&D Projects: GA ČR GAP503/10/0664 Institutional support: RVO:61388971 Keywords : Mass spectrometry * Bacteria * Identification Subject RIV: EE - Microbiology, Virology Impact factor: 2.227, year: 2013

  1. Antimicrobial resistant bacteria in the food chain

    DEFF Research Database (Denmark)

    Wegener, Henrik Caspar


    Antimicrobials are used for treatment and prevention of disease in food animals and as feed additives for growth promotion. All uses lead to the development of resistant bacteria, some of which are pathogenic to humans. Current main concerns are with resistance in Salmonella and Campylobacter...

  2. Bioluminescent bacteria: lux genes as environmental biosensors


    Nunes-Halldorson,Vânia da Silva; Duran,Norma Letícia


    Bioluminescent bacteria are widespread in natural environments. Over the years, many researchers have been studying the physiology, biochemistry and genetic control of bacterial bioluminescence. These discoveries have revolutionized the area of Environmental Microbiology through the use of luminescent genes as biosensors for environmental studies. This paper will review the chronology of scientific discoveries on bacterial bioluminescence and the current applications of bioluminescence in env...

  3. (VAM) and phosphate solubilizing bacteria (PSB)

    African Journals Online (AJOL)



    Sep 18, 2013 ... mycorrhiza (VAM), and phosphate solubilising bacteria (PSB) individually and in .... Two-way analysis of variance (ANOVA) was carried out at a 0.05 level of significance on the data and SPSS version 13.0 was used.

  4. Control of indigenous pathogenic bacteria in seafood

    DEFF Research Database (Denmark)

    Huss, Hans Henrik


    The pathogenic bacteria indigenous to the aquatic and general environment are listed. Their distribution in nature, prevalence in seafood and the possibilities for growth of these organisms in various types of products are outlined These data, combined with what is known regarding the epidemiology...

  5. Filamentous bacteria transport electrons over centimetre distances

    DEFF Research Database (Denmark)

    Pfeffer, Christian; Larsen, Steffen; Song, Jie


    across centimetre-wide zones. Here we present evidence that the native conductors are long, filamentous bacteria. They abounded in sediment zones with electric currents and along their length they contained strings with distinct properties in accordance with a function as electron transporters. Living...

  6. Halophilic and haloalkaliphilic sulfur-oxidizing bacteria

    NARCIS (Netherlands)

    Sorokin, D.Y.; Banciu, H.; Robertson, L.A.; Kuenen, J.G.; Muntyan, M.S.; Muyzer, G.; Rosenberg, E.; DeLong, F.; Delong, E.; Lory, S.; Stackebrandt, E.; Thompson, F.


    Chemotrophic sulfur-oxidizing bacteria (SOB) represent an important functional group of microorganisms responsible for the dark oxidation of reduced sulfur compounds generated by sulfidogens. Until recently, only a single genus of halophilic SOB (Halothiobacillus) has been described, and nothing was

  7. Bacteria Isolated from Post-Partum Infections

    Directory of Open Access Journals (Sweden)

    Nahid Arianpour


    Full Text Available Objective: This study was undertaken with an aim to determine bacterial species involved in post partum infections and also their abundance in patients admitted to at Khanevadeh hospital. In this study out of three different kinds of postpartum infections (i.e. genital, breast and urinary tract, only genital infection is considered.Materials and Methods: Post partum infection among 6077 patients (inpatients and re-admitted patients of Khanevadeh hospital from 2003 till 2008 was studied in this descriptive study. Samples were collected from patients for laboratory diagnosis to find out the causative organisms.Results: Follow up of mothers after delivery revealed 7.59% (461 patients had post partum infection, out of which 1.03% (63 patients were re-hospitalized. Infection was more often among younger mothers. Bacteria isolated and identified were both aerobic and anaerobic cocci and bacilli, majority of which were normal flora of the site of infection. Though, some pathogenic bacteria like Staphylococcus aureus, Neisseria gonorrhea, Chlamydia trachomatis,were also the causative agents. The commonest infection was infection at the site of episiotomy. Conclusion: Puerperal infection was detected in of 7.59% mothers. Bacteria isolated were both aerobic and anaerobic cocci and bacilli, majority of which were normal flora. However; some pathogenic bacteria were isolated.

  8. Serpins in unicellular Eukarya, Archaea, and Bacteria:

    DEFF Research Database (Denmark)

    Roberts, T.H.; Hejgaard, Jørn; Saunders, N.F.W


    , where serpins were found in only 4 of 13 genera, and Bacteria, in only 9 of 56 genera. The serpins from unicellular organisms appear to be phylogenetically distinct from all of the clades of higher eukaryotic serpins. Most of the sequences from unicellular organisms have the characteristics...

  9. Bacteria as transporters of phosphorus through soil

    DEFF Research Database (Denmark)

    Glæsner, N.; Bælum, Jacob; Jacobsen, C. S.


    The transport of phosphorus (P) from agricultural land has led to the eutrophication of surface waters worldwide, especially in areas with intensive animal production. In this research, we investigated the role of bacteria in the leaching of P through three agricultural soils with different...

  10. Multidrug transporters in lactic acid bacteria

    NARCIS (Netherlands)

    Mazurkiewicz, P; Sakamoto, K; Poelarends, GJ; Konings, WN

    Gram-positive lactic acid bacteria possess several Multi-Drug Resistance systems (MDRs) that excrete out of the cell a wide variety of mainly cationic lipophilic cytotoxic compounds as well as many clinically relevant antibiotics. These MDRs are either proton/drug antiporters belonging to the major

  11. Drug efflux proteins in multidrug resistant bacteria

    NARCIS (Netherlands)

    vanVeen, HW; Konings, WN

    Bacteria contain an array of transport proteins in their cytoplasmic membrane. Many of these proteins play an important role in conferring resistance to toxic compounds. The multidrug efflux systems encountered in prokaryotic cells are very similar to those observed in eukaryotic cells. Therefore, a

  12. Bioluminescent hydrocarbonclastic bacteria of the Niger Delta ...

    African Journals Online (AJOL)

    Utilization of three petroleum hydrocarbons (Mobil SAE 40 Engine Oil, Diesel and Bonny light Crude Oil) by four bioluminescent bacteria (Vibrio harveyi, V. fisheri, Photobacterium leiognathi and P. Phosphoreum isolated from the Bonny estuary in the Niger Delta, Nigeria was investigated. Microbial utilization was monitored ...

  13. Pathomorphology and aerobic bacteria associated with pneumonia ...

    African Journals Online (AJOL)

    Pneumonia occurs in all ages of sheep and goats, in all breeds, in every country of the world causing heavy economic losses. The aim of this study was to determine the prevalence of pneumonia and aerobic bacteria flora associated with it in small ruminants slaughtered at the Nsukka abattoir. Pneumonic lung of small ...

  14. Metabolic plasticity for isoprenoid biosynthesis in bacteria. (United States)

    Pérez-Gil, Jordi; Rodríguez-Concepción, Manuel


    Isoprenoids are a large family of compounds synthesized by all free-living organisms. In most bacteria, the common precursors of all isoprenoids are produced by the MEP (methylerythritol 4-phosphate) pathway. The MEP pathway is absent from archaea, fungi and animals (including humans), which synthesize their isoprenoid precursors using the completely unrelated MVA (mevalonate) pathway. Because the MEP pathway is essential in most bacterial pathogens (as well as in the malaria parasites), it has been proposed as a promising new target for the development of novel anti-infective agents. However, bacteria show a remarkable plasticity for isoprenoid biosynthesis that should be taken into account when targeting this metabolic pathway for the development of new antibiotics. For example, a few bacteria use the MVA pathway instead of the MEP pathway, whereas others possess the two full pathways, and some parasitic strains lack both the MVA and the MEP pathways (probably because they obtain their isoprenoids from host cells). Moreover, alternative enzymes and metabolic intermediates to those of the canonical MVA or MEP pathways exist in some organisms. Recent work has also shown that resistance to a block of the first steps of the MEP pathway can easily be developed because several enzymes unrelated to isoprenoid biosynthesis can produce pathway intermediates upon spontaneous mutations. In the present review, we discuss the major advances in our knowledge of the biochemical toolbox exploited by bacteria to synthesize the universal precursors for their essential isoprenoids.

  15. Chitinolytic bacteria of the mammal digestive tract

    Czech Academy of Sciences Publication Activity Database

    Šimůnek, Jiří; Hodrová, Blanka; Bartoňová, H.; Kopečný, Jan


    Roč. 46, č. 1 (2001), s. 76-78 ISSN 0015-5632 R&D Projects: GA ČR GA525/00/0984; GA AV ČR KSK5052113 Keywords : chitinolytic bacteria Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.776, year: 2001

  16. Tolerance of anaerobic bacteria to chlorinated solvents. (United States)

    Koenig, Joanna C; Groissmeier, Kathrin D; Manefield, Mike J


    The aim of this research was to evaluate the effects of four chlorinated aliphatic hydrocarbons (CAHs), perchloroethene (PCE), carbon tetrachloride (CT), chloroform (CF) and 1,2-dichloroethane (1,2-DCA), on the growth of eight anaerobic bacteria: four fermentative species (Escherichia coli, Klebsiella sp., Clostridium sp. and Paenibacillus sp.) and four respiring species (Pseudomonas aeruginosa, Geobacter sulfurreducens, Shewanella oneidensis and Desulfovibrio vulgaris). Effective concentrations of solvents which inhibited growth rates by 50% (EC50) were determined. The octanol-water partition coefficient or log Po/w of a CAH proved a generally satisfactory measure of its toxicity. Most species tolerated approximately 3-fold and 10-fold higher concentrations of the two relatively more polar CAHs CF and 1,2-DCA, respectively, than the two relatively less polar compounds PCE and CT. EC50 values correlated well with growth rates observed in solvent-free cultures, with fast-growing organisms displaying higher tolerance levels. Overall, fermentative bacteria were more tolerant to CAHs than respiring species, with iron- and sulfate-reducing bacteria in particular appearing highly sensitive to CAHs. These data extend the current understanding of the impact of CAHs on a range of anaerobic bacteria, which will benefit the field of bioremediation.

  17. The proteolytic systems of lactic acid bacteria

    NARCIS (Netherlands)

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


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

  18. Proteolytic enzymes of lactic acid bacteria

    NARCIS (Netherlands)

    Law, J; Haandrikman, A

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

  19. Biological Potential of Chitinolytic Marine Bacteria

    DEFF Research Database (Denmark)

    Paulsen, Sara Skøtt; Andersen, Birgitte; Gram, Lone


    Chitinolytic microorganisms secrete a range of chitin modifying enzymes, which can be exploited for production of chitin derived products or as fungal or pest control agents. Here, we explored the potential of 11 marine bacteria (Pseudoalteromonadaceae, Vibrionaceae) for chitin degradation using...

  20. Exopolysaccharides produced by lactic acid bacteria

    NARCIS (Netherlands)

    Caggianiello, Graziano; Kleerebezem, Michiel; Spano, Giuseppe


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

  1. Radiographic markers - A reservoir for bacteria?

    International Nuclear Information System (INIS)

    Tugwell, Jenna; Maddison, Adele


    Introduction: Amongst the most frequently handled objects in the radiology department are radiographic markers. They are personal accessories used with every patient, and are kept in the radiographers pockets when not utilised. Upon enquiry it was discovered that many radiographers disregarded the potential of these accessories to become a vector for cross-contamination thus never or rarely clean them. The aims of this study were therefore to identify if radiographic markers are a reservoir for bacteria and to establish an effective cleaning method for decontaminating them. Methodology: 25 radiographers/student radiographers were selected for this study. Swabbing of their markers prior and post cleaning took place. The microbiology laboratory subsequently analyzed the results by quantifying and identifying the bacteria present. The participants also completed a closed questionnaire regarding their markers (e.g. frequency of cleaning and type of marker) to help specify the results gained from the swabbing procedure. Results: From the sample swabbed, 92% were contaminated with various organisms including Staphylococcus and Bacillus species, the amount of bacteria present ranged from 0 to >50 CFU. There were no significant differences between disinfectant wipes and alcohol gel in decontaminating the markers. Both successfully reduced their bacterial load, with 80% of the markers post cleaning having 0 CFU. Conclusion: The results indicated that radiographic markers can become highly contaminated with various organisms thus serve as a reservoir for bacteria. In addition, the markers need to be cleaned on a regular basis, with either disinfectant wipes or alcohol gel to reduce their bacterial load.

  2. Heterotrophic bacteria associated with the green alga

    NARCIS (Netherlands)

    Ismail, A.; Ktari, L.; Ahmed, M.; Bolhuis, H.; Bouhaouala-Zahar, B.; Stal, L.J.; Boudabbous, A.; El Bour, M.


    Heterotrophic bacteria associated with the green alga Ulva rigida, collected from the coast of Tunisia, were isolated andsubsequently identified by their 16S rRNA gene sequences and by phylogenetic analysis. The 71 isolates belong to four phyla:Proteobacteria (Alpha-and Gamma- subclasses),

  3. The interaction of bacteria and metal surfaces

    International Nuclear Information System (INIS)

    Mansfeld, Florian


    This review discusses different examples for the interaction of bacteria and metal surfaces based on work reported previously by various authors and work performed by the author with colleagues at other institutions and with his graduate students at CEEL. Traditionally it has been assumed that the interaction of bacteria with metal surfaces always causes increased corrosion rates ('microbiologically influenced corrosion' (MIC)). However, more recently it has been observed that many bacteria can reduce corrosion rates of different metals and alloys in many corrosive environments. For example, it has been found that certain strains of Shewanella can prevent pitting of Al 2024 in artificial seawater, tarnishing of brass and rusting of mild steel. It has been observed that corrosion started again when the biofilm was killed by adding antibiotics. The mechanism of corrosion protection seems to be different for different bacteria since it has been found that the corrosion potential E corr became more negative in the presence of Shewanella ana and algae, but more positive in the presence of Bacillus subtilis. These findings have been used in an initial study of the bacterial battery in which Shewanella oneidensis MR-1 was added to a cell containing Al 2024 and Cu in a growth medium. It was found that the power output of this cell continuously increased with time. In the microbial fuel cell (MFC) bacteria oxidize the fuel and transfer electrons directly to the anode. In initial studies EIS has been used to characterize the anode, cathode and membrane properties for different operating conditions of a MFC that contained Shewanella oneidensis MR-1. Cell voltage (V)-current density (i) curves were obtained using potentiodynamic sweeps. The current output of a MFC has been monitored for different experimental conditions

  4. The interaction of bacteria and metal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Mansfeld, Florian [Corrosion and Environmental Effects Laboratory (CEEL), The Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089-0241 (United States)


    This review discusses different examples for the interaction of bacteria and metal surfaces based on work reported previously by various authors and work performed by the author with colleagues at other institutions and with his graduate students at CEEL. Traditionally it has been assumed that the interaction of bacteria with metal surfaces always causes increased corrosion rates ('microbiologically influenced corrosion' (MIC)). However, more recently it has been observed that many bacteria can reduce corrosion rates of different metals and alloys in many corrosive environments. For example, it has been found that certain strains of Shewanella can prevent pitting of Al 2024 in artificial seawater, tarnishing of brass and rusting of mild steel. It has been observed that corrosion started again when the biofilm was killed by adding antibiotics. The mechanism of corrosion protection seems to be different for different bacteria since it has been found that the corrosion potential E{sub corr} became more negative in the presence of Shewanella ana and algae, but more positive in the presence of Bacillus subtilis. These findings have been used in an initial study of the bacterial battery in which Shewanella oneidensis MR-1 was added to a cell containing Al 2024 and Cu in a growth medium. It was found that the power output of this cell continuously increased with time. In the microbial fuel cell (MFC) bacteria oxidize the fuel and transfer electrons directly to the anode. In initial studies EIS has been used to characterize the anode, cathode and membrane properties for different operating conditions of a MFC that contained Shewanella oneidensis MR-1. Cell voltage (V) - current density (i) curves were obtained using potentiodynamic sweeps. The current output of a MFC has been monitored for different experimental conditions. (author)

  5. [Methanotrophic bacteria of acid sphagnum bogs]. (United States)

    Dedysh, S N


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

  6. Anaerobic bacteria in wastewater treatment plant. (United States)

    Cyprowski, Marcin; Stobnicka-Kupiec, Agata; Ławniczek-Wałczyk, Anna; Bakal-Kijek, Aleksandra; Gołofit-Szymczak, Małgorzata; Górny, Rafał L


    The objective of this study was to assess exposure to anaerobic bacteria released into air from sewage and sludge at workplaces from a wastewater treatment plant (WWTP). Samples of both sewage and sludge were collected at six sampling points and bioaerosol samples were additionally collected (with the use of a 6-stage Andersen impactor) at ten workplaces covering different stages of the technological process. Qualitative identification of all isolated strains was performed using the biochemical API 20A test. Additionally, the determination of Clostridium pathogens was carried out using 16S rRNA gene sequence analysis. The average concentration of anaerobic bacteria in the sewage samples was 5.49 × 10 4 CFU/mL (GSD = 85.4) and in sludge-1.42 × 10 6 CFU/g (GSD = 5.1). In turn, the average airborne bacterial concentration was at the level of 50 CFU/m 3 (GSD = 5.83) and the highest bacterial contamination (4.06 × 10 3  CFU/m 3 ) was found in winter at the bar screens. In total, 16 bacterial species were determined, from which the predominant strains belonged to Actinomyces, Bifidobacterium, Clostridium, Propionibacterium and Peptostreptococcus genera. The analysis revealed that mechanical treatment processes were responsible for a substantial emission of anaerobic bacteria into the air. In both the sewage and air samples, Clostridium perfringens pathogen was identified. Anaerobic bacteria were widely present both in the sewage and in the air at workplaces from the WWTP, especially when the technological process was performed in closed spaces. Anaerobic bacteria formed small aggregates with both wastewater droplets and dust particles of sewage sludge origin and as such may be responsible for adverse health outcomes in exposed workers.

  7. Antibacterial activity of silver-killed bacteria: the "zombies" effect (United States)

    Wakshlak, Racheli Ben-Knaz; Pedahzur, Rami; Avnir, David


    We report a previously unrecognized mechanism for the prolonged action of biocidal agents, which we denote as the zombies effect: biocidally-killed bacteria are capable of killing living bacteria. The concept is demonstrated by first killing Pseudomonas aeruginosa PAO1 with silver nitrate and then challenging, with the dead bacteria, a viable culture of the same bacterium: Efficient antibacterial activity of the killed bacteria is observed. A mechanism is suggested in terms of the action of the dead bacteria as a reservoir of silver, which, due to Le-Chatelier's principle, is re-targeted to the living bacteria. Langmuirian behavior, as well as deviations from it, support the proposed mechanism.

  8. Interactions between Paramyxoviruses and Bacteria: Implications for Pathogenesis and Intervention

    NARCIS (Netherlands)

    D.T. Nguyen (Tien)


    markdownabstract__Abstract__ Globally, respiratory tract diseases caused by bacteria and viruses are an important burden of disease. Respiratory bacteria (Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and Staphylococcus aureus) can colonize the upper respiratory tract.

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

    African Journals Online (AJOL)



    Feb 7, 2011 ... the diversity and dynamics of lactic acid bacteria (LAB) population in fresh ..... combining morphological, biochemical and molecular data are important for ..... acid bacteria from fermented maize (Kenkey) and their interactions.

  10. Oh What a Tangled Biofilm Web Bacteria Weave (United States)

    ... Home Page Oh What a Tangled Biofilm Web Bacteria Weave By Elia Ben-Ari Posted May 1, ... a suitable surface, some water and nutrients, and bacteria will likely put down stakes and form biofilms. ...

  11. The Effect of Bacteria Penetration on Chalk Permeability

    DEFF Research Database (Denmark)

    Halim, Amalia Yunita; Shapiro, Alexander; Nielsen, Sidsel Marie

    number of B. licheniformis was detected on the effluent compared with P. putida. However, in the experiment with B. licheniformis mainly spores were detected in the effluent. The core permeability decreased rapidly during injection of bacteria and a starvation period of 12 days did not allow......Bacteria selective plugging is one of the mechanisms through which microorganisms can be applied for enhanced oil recovery. Bacteria can plug the water-bearing zones of a reservoir, thus altering the flow paths and improving sweep efficiency. It is known that the bacteria can penetrate deeply...... into reservoirs, however, a complete understanding of the penetration behavior of bacteria is lacking, especially in chalk formations where the pore throat sizes are almost comparable with the sizes of bacteria vegetative cells. This study investigates the penetration of bacteria into chalk. Two bacteria types...

  12. Developing new bacteria subroutines in the SWAT model (United States)

    Fecal bacteria observations from four different sites in Korea and the US demonstrate seasonal variability, showing a significant relationship with temperature (Figure 1); fecal indicator bacteria (FIB) concentrations are relatively higher in summer and lower in winter , including Stillwater river (...

  13. Bacteria Associated with Fresh Tilapia Fish (Oreochromis niloticus ...

    African Journals Online (AJOL)


    Keywords: Bacteria, Tilapia fish and Sokoto central market. INTRODUCTION ... The bacteria are transmitted by fish that have made contact ... with which a product spoils is also related to the .... Base on the percentage frequency of occurance ,.

  14. Frequency of Resistance and Susceptible Bacteria Isolated from Houseflies

    Directory of Open Access Journals (Sweden)

    B Davari


    Conclusion: Houseflies collected from hospitals and slaughterhouse may be involved in the spread of drug resistant bacteria and may increase the potential of human exposure to drug resistant bacteria.

  15. Have sex or not? Lessons from bacteria. (United States)

    Lodé, T


    Sex is one of the greatest puzzles in evolutionary biology. A true meiotic process occurs only in eukaryotes, while in bacteria, gene transcription is fragmentary, so asexual reproduction in this case really means clonal reproduction. Sex could stem from a signal that leads to increased reproductive output of all interacting individuals and could be understood as a secondary consequence of primitive metabolic reactions. Meiotic sex evolved in proto-eukaryotes to solve a problem that bacteria did not have, namely a large amount of DNA material, occurring in an archaic step of proto-cell formation and genetic exchanges. Rather than providing selective advantages through reproduction, sex could be thought of as a series of separate events which combines step-by-step some very weak benefits of recombination, meiosis, gametogenesis and syngamy. Copyright © 2012 S. Karger AG, Basel.

  16. Mucosal immunity to pathogenic intestinal bacteria. (United States)

    Perez-Lopez, Araceli; Behnsen, Judith; Nuccio, Sean-Paul; Raffatellu, Manuela


    The intestinal mucosa is a particularly dynamic environment in which the host constantly interacts with trillions of commensal microorganisms, known as the microbiota, and periodically interacts with pathogens of diverse nature. In this Review, we discuss how mucosal immunity is controlled in response to enteric bacterial pathogens, with a focus on the species that cause morbidity and mortality in humans. We explain how the microbiota can shape the immune response to pathogenic bacteria, and we detail innate and adaptive immune mechanisms that drive protective immunity against these pathogens. The vast diversity of the microbiota, pathogens and immune responses encountered in the intestines precludes discussion of all of the relevant players in this Review. Instead, we aim to provide a representative overview of how the intestinal immune system responds to pathogenic bacteria.

  17. Ancient bacteria show evidence of DNA repair

    DEFF Research Database (Denmark)

    Johnson, Sarah Stewart; Hebsgaard, Martin B; Christensen, Torben R


    -term survival of bacteria sealed in frozen conditions for up to one million years. Our results show evidence of bacterial survival in samples up to half a million years in age, making this the oldest independently authenticated DNA to date obtained from viable cells. Additionally, we find strong evidence...... geological timescales. There has been no direct evidence in ancient microbes for the most likely mechanism, active DNA repair, or for the metabolic activity necessary to sustain it. In this paper, we couple PCR and enzymatic treatment of DNA with direct respiration measurements to investigate long...... that this long-term survival is closely tied to cellular metabolic activity and DNA repair that over time proves to be superior to dormancy as a mechanism in sustaining bacteria viability....

  18. Protein-Injection Machines in Bacteria. (United States)

    Galán, Jorge E; Waksman, Gabriel


    Many bacteria have evolved specialized nanomachines with the remarkable ability to inject multiple bacterially encoded effector proteins into eukaryotic or prokaryotic cells. Known as type III, type IV, and type VI secretion systems, these machines play a central role in the pathogenic or symbiotic interactions between multiple bacteria and their eukaryotic hosts, or in the establishment of bacterial communities in a diversity of environments. Here we focus on recent progress elucidating the structure and assembly pathways of these machines. As many of the interactions shaped by these machines are of medical importance, they provide an opportunity to develop novel therapeutic approaches to combat important human diseases. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. Seeing Streptococcus pneumoniae, a Common Killer Bacteria

    DEFF Research Database (Denmark)

    Kjærgaard, Rikke Schmidt; Andersen, Ebbe Sloth


    Look around you. The diversity and complexity of life on earth is overwhelming and data continues to grow. In our desire to understand and explain everything scientifically from molecular evolution to supernovas we depend on visual representations. This paper investigates visual representations...... of the bacteria Streptococcus pneumoniae by use of ink, watercolours and computer graphics. We propose a novel artistic visual rendering of Streptococcus pneumoniae and ask what the value of these kind of representations are compared to traditional scientific data. We ask if drawings and computer......-assisted representations can add to our scientific knowledge about this dangerous bacteria. Is there still a role for the scientific illustrator in the scientific process and synthesis of scientific knowledge?...

  20. [Synthesis of reserve polyhydroxyalkanoates by luminescent bacteria]. (United States)

    Boiandin, A N; Kalacheva, G S; Rodicheva, E K; Volova, T G


    The ability of marine luminescent bacteria to synthesize polyesters of hydroxycarboxylic acids (polyhydroxyalkanoates, PHA) as reserve macromolecules was studied. Twenty strains from the collection of the luminescent bacteria CCIBSO (WDSM839) of the Institute of Biophysics, Siberian Branch, Russian Academy of Sciences, assigned to different taxa (Photobacterium leiognathi, Ph. phosphoreum, Vibrio harveyi, and V. fischeri) were analyzed. The most productive strains were identified, and the conditions ensuring high polymer yields in batch culture (40-70% of the cell dry mass weight) were determined. The capacity of synthesizing two- and three-component polymers containing hydroxybutyric acid as the main monomer and hydroxyvaleric and hydroxyhexanoic acids was revealed in Ph. leiognathi and V. harveyi strains. The results allow luminescent microorganisms to be regarded as new producers of multicomponent polyhydroxyalkanoates.

  1. New Insight on the Response of Bacteria to Fluoride


    Breaker, R.R.


    Fluoride has been used for decades to prevent caries and it is well established that this anion can inhibit the growth of bacteria. However, the precise effects that fluoride has on bacteria and the mechanisms that bacteria use to overcome fluoride toxicity have largely remained unexplored. Recently, my laboratory reported the discovery of biological systems that bacteria use to sense fluoride and reduce fluoride toxicity. These sensors and their associated genes are very widespread in biolog...

  2. Antioxidant and Antimicrobial Potential of the Bifurcaria bifurcata Epiphytic Bacteria


    Horta, André; Pinteus, Susete; Alves, Celso; Fino, Nádia; Silva, Joana; Fernandez, Sara; Rodrigues, Américo; Pedrosa, Rui


    This article belongs to the Special Issue Selected Papers from the 14th International Symposium on Marine Natural Products Surface-associated marine bacteria are an interesting source of new secondary metabolites. The aim of this study was the isolation and identification of epiphytic bacteria from the marine brown alga, Bifurcaria bifurcata, and the evaluation of the antioxidant and antimicrobial activity of bacteria extracts. The identification of epiphytic bacteria was determined by 16S...

  3. Bactericidal effects of antibiotics on slowly growing and nongrowing bacteria.


    Eng, R H; Padberg, F T; Smith, S M; Tan, E N; Cherubin, C E


    Antimicrobial agents are most often tested against bacteria in the log phase of multiplication to produce the maximum bactericidal effect. In an infection, bacteria may multiply less optimally. We examined the effects of several classes of antimicrobial agents to determine their actions on gram-positive and gram-negative bacteria during nongrowing and slowly growing phases. Only ciprofloxacin and ofloxacin exhibited bactericidal activity against nongrowing gram-negative bacteria, and no antib...

  4. [Application of anaerobic bacteria detection in oral and maxillofacial infection]. (United States)

    Bao, Zhen-ying; Lin, Qin; Meng, Yan-hong; He, Chun; Su, Jia-zeng; Peng, Xin


    To investigate the distribution and drug resistance of anaerobic bacteria in the patients with oral and maxillofacial infection. Aerobic and anaerobic bacteria cultures from 61 specimens of pus from the patients with oral and maxillofacial infection in the Department of Oral and Maxillofacial Surgery, Peking University School of Stomatology were identified. The culture type was evaluated by API 20A kit and drug resistance test was performed by Etest method. The clinical data and antibacterial agents for the treatment of the 61 cases were collected, and the final outcomes were recorded. The bacteria cultures were isolated from all the specimens, with aerobic bacteria only in 6 cases (9.8%), anaerobic bacteria only in 7 cases (11.5%), and both aerobic and anaerobic bacteria in 48 cases (78.7%). There were 55 infected cases (90.2%) with anaerobic bacteria, and 81 anaerobic bacteria stains were isolated. The highest bacteria isolation rate of Gram positive anaerobic bacteria could be found in Peptostreptococcus, Bifidobacterium and Pemphigus propionibacterium. No cefoxitin, amoxicillin/carat acid resistant strain was detected in the above three Gram positive anaerobic bacteria. The highest bacteria isolation rate of Gram negative anaerobic bacteria could be detected in Porphyromonas and Prevotella. No metronidazole, cefoxitin, amoxicillin/carat acid resistant strain was found in the two Gram negative anaerobic bacteria. In the study, 48 patients with oral and maxillofacial infection were treated according to the results of drug resistance testing, and the clinical cure rate was 81.3%. Mixed aerobic and anaerobic bacteria cultures are very common in most oral and maxillofacial infection patients. Anaerobic bacteria culture and drug resistance testing play an important role in clinical treatment.

  5. Cellulase Production by Bacteria: A Review


    Sadhu Sangrila; Maiti Tushar Kanti


    Cellulose is an abundant natural biopolymer on earth and most dominating Agricultural waste. This cellulosic biomass is a renewable and abundant resource with great potential for bioconversion to value-added bioproducts. It can be degraded by cellulase produced by cellulolytic bacteria. This enzyme has various industrial applications and now considered as major group of industrial enzyme. The review discusses application of cellulase, classification of cellulase, quantification...

  6. Tumour targeting with systemically administered bacteria.

    LENUS (Irish Health Repository)

    Morrissey, David


    Challenges for oncology practitioners and researchers include specific treatment and detection of tumours. The ideal anti-cancer therapy would selectively eradicate tumour cells, whilst minimising side effects to normal tissue. Bacteria have emerged as biological gene vectors with natural tumour specificity, capable of homing to tumours and replicating locally to high levels when systemically administered. This property enables targeting of both the primary tumour and secondary metastases. In the case of invasive pathogenic species, this targeting strategy can be used to deliver genes intracellularly for tumour cell expression, while non-invasive species transformed with plasmids suitable for bacterial expression of heterologous genes can secrete therapeutic proteins locally within the tumour environment (cell therapy approach). Many bacterial genera have been demonstrated to localise to and replicate to high levels within tumour tissue when intravenously (IV) administered in rodent models and reporter gene tagging of bacteria has permitted real-time visualisation of this phenomenon. Live imaging of tumour colonising bacteria also presents diagnostic potential for this approach. The nature of tumour selective bacterial colonisation appears to be tumour origin- and bacterial species- independent. While originally a correlation was drawn between anaerobic bacterial colonisation and the hypoxic nature of solid tumours, it is recently becoming apparent that other elements of the unique microenvironment within solid tumours, including aberrant neovasculature and local immune suppression, may be responsible. Here, we consider the pre-clinical data supporting the use of bacteria as a tumour-targeting tool, recent advances in the area, and future work required to develop it into a beneficial clinical tool.

  7. Chemotactic waves of bacteria at the mesoscale


    Calvez, Vincent


    The existence of travelling waves for a model of concentration waves of bacteria is investigated. The model consists in a kinetic equation for the biased motion of cells following a run-and-tumble process, coupled with two reaction-diffusion equations for the chemical signals. Strong mathematical difficulties arise in comparison with the diffusive regime which was studied in a previous work. The cornerstone of the proof consists in establishing monotonicity properties of the spatial density o...

  8. Transfer of DNA from Bacteria to Eukaryotes

    Directory of Open Access Journals (Sweden)

    Benoît Lacroix


    Full Text Available Historically, the members of the Agrobacterium genus have been considered the only bacterial species naturally able to transfer and integrate DNA into the genomes of their eukaryotic hosts. Yet, increasing evidence suggests that this ability to genetically transform eukaryotic host cells might be more widespread in the bacterial world. Indeed, analyses of accumulating genomic data reveal cases of horizontal gene transfer from bacteria to eukaryotes and suggest that it represents a significant force in adaptive evolution of eukaryotic species. Specifically, recent reports indicate that bacteria other than Agrobacterium, such as Bartonella henselae (a zoonotic pathogen, Rhizobium etli (a plant-symbiotic bacterium related to Agrobacterium, or even Escherichia coli, have the ability to genetically transform their host cells under laboratory conditions. This DNA transfer relies on type IV secretion systems (T4SSs, the molecular machines that transport macromolecules during conjugative plasmid transfer and also during transport of proteins and/or DNA to the eukaryotic recipient cells. In this review article, we explore the extent of possible transfer of genetic information from bacteria to eukaryotic cells as well as the evolutionary implications and potential applications of this transfer.

  9. Intracellular bacteria: the origin of dinoflagellate toxicity. (United States)

    Silva, E S


    Dinoflagellate blooms of the same species have been registered either as toxic or nontoxic and, in the latter case, toxicity may be of different types. A hypothesis has been formulated according to which the bacteria having in some way taken part in the toxin formation are either inside the dinoflagellate cell or in the nutritive liquid. The presence of intracellular bacteria in those microorganisms has been studied mainly in material from cultures, a few from the sea, and several strains were isolated from different species. Experiments with crossed inoculations have shown that the bacterial strain from Gonyaulax tamarensis caused the cells of some other species to become toxic. From nontoxic clonal cultures of Prorocentrum balticum, Glenodinium foliaceum, and Gyrodinium instriatum, after inoculation of that bacterial strain, cultures were obtained whose cell extracts showed the same kind of toxicity as G. tamarensis. No toxic action could be found in the extracts of the bacterial cells form the assayed strains. The interference of intracellular bacteria in the metabolism of dinoflagellates must be the main cause of their toxicity.

  10. Acoustic manipulation of bacteria cells suspensions (United States)

    GutiéRrez-Ramos, Salomé; Hoyos, Mauricio; Aider, Jean Luc; Ruiz, Carlos; Acoustofluidics Team Team; Soft; Bio Group Collaboration

    An acoustic contacless manipulation gives advantages in the exploration of the complex dynamics enviroment that active matter exhibits. Our works reports the control confinement and dispersion of Escherichia coliRP437-pZA3R-YFP suspensions (M9Glu-Ca) via acoustic levitation.The manipulation of the bacteria bath in a parallel plate resonator is achieved using the acoustic radiation force and the secondary radiation force. The primary radiation force generates levitation of the bacteria cells at the nodal plane of the ultrasonic standing wave generated inside the resonator. On the other side, secondary forces leads to the consolidation of stable aggregates. All the experiments were performed in the acoustic trap described, where we excite the emission plate with a continuous sinusoidal signal at a frequency in the order of MHz and a quartz slide as the reflector plate. In a typical experiment we observed that, before the input of the signal, the bacteria cells exhibit their typical run and tumble behavior and after the sound is turned on all of them displace towards the nodal plane, and instantaneously the aggregation begins in this region. CNRS French National Space Studies, CONACYT Mexico.

  11. Fecal indicator bacteria at Havana Bay

    International Nuclear Information System (INIS)

    Lopez Perez, Lisse; Gomez D'Angelo, Yamiris; Beltran Gonzalez, Jesus; Alvarez Valiente, Reinaldo


    Aims: Fecal indicator bacteria concentrations were evaluated in Havana Bay. Methods: Concentrations of traditional fecal indicator bacteria were calculated between April 2010 and February 2011, by MPN methods. Concentrations of thermo tolerant coliform (CTT), Escherichia coli, fecal streptococci (EF), intestinal enterococci (ENT) in seawater, and Clostridium perfringens in sediment surface, were determined. Results: CTT and E. coli levels were far above Cuban water quality standard for indirect contact with water, showing the negative influence of sewage and rivers on the bay. The EF and ENT were measured during sewage spills at the discharge site and they were suitable indicators of fecal contamination, but these indicators didn't show the same behavior in other selected sites. This result comes from its well-known inactivation by solar light in tropical zones and the presumable presence of humid acids in the waters of the bay. Conclusion: Fecal indicator bacteria and its statistical relationships reflect recent and chronic fecal contamination at the bay and near shores.

  12. Alkaline phosphatase activity of rumen bacteria. (United States)

    Cheng, K J; Costerton, J W


    Of the 54 strains of rumen bacteria examined for alkaline phosphatase (APase) production, 9 of 33 gram-negative strains and none of 21 gram-positive strains produced the enzyme. The APase of the cells of the three strains of Bacteroides ruminicola that produced significant amounts of the enzyme was located in the periplasmic area of the cell envelope, whereas the enzyme was located in the strains of Selenomonas ruminantium and Succinivibrio dextrinosolvens was associated with the outer membrane. The localization of APase production in the cells of natural populations of rumen bacteria from hay-fed sheep was accomplished by reaction product deposition, and both the proportion of APase-producing bacteria and the location of the enzyme in the cell envelope of the producing cells could be determined. We suggest that this procedure is useful in detecting shifts in the bacterial population and the release of cell-bound APase that accompany feedlot bloat and other sequelae of dietary manipulation in ruminants.

  13. Soil bacteria for remediation of polluted soils

    Energy Technology Data Exchange (ETDEWEB)

    Springael, D; Bastiaens, L; Carpels, M; Mergaey, M; Diels, L


    Soil bacteria, specifically adapted to contaminated soils, may be used for the remediation of polluted soils. The Flemish research institute VITO has established a collection of bacteria, which were isolated from contaminated areas. This collection includes microbacteria degrading mineral oils (Pseudomonas sp., Acinetobacter sp. and others), microbacteria degrading polycyclic aromatic hydrocarbons (genera Sphingomonas and Mycobacterium), microbacteria degrading polychlorobiphenyls (genus Ralstonia and strains related to beta-Proteobacteria), and metal resistant bacteria with plasmid borne resistances to Cd, Zn, Ni, Co, Cu, Hg, and Cr. Bench-scale reactors were developed to investigate the industrial feasibility of bioremediation. Batch Stirred Tank Reactors were used to evaluate the efficiency of oil degraders. Soils, contaminated with non-ferrous metals, were treated using a Bacterial Metal Slurry Reactor. It was found that the reduction of the Cd concentration may vary strongly from sample to sample: reduction factors vary from 95 to 50%. Is was shown that Cd contained in metallic sinter and biologically unavailable Cd could not be removed.

  14. Magnesium and manganese content of halophilic bacteria

    International Nuclear Information System (INIS)

    de Medicis, E.; Paquette, J.; Gauthier, J.J.; Shapcott, D.


    Magnesium and manganese contents were measured by atomic absorption spectrophotometry in bacteria of several halophilic levels, in Vibrio costicola, a moderately halophilic eubacterium growing in 1 M NaCl, Halobacterium volcanii, a halophilic archaebacterium growing in 2.5 NaCl, Halobacterium cutirubrum, an extremely halophilic archaebacterium growing in 4 M NaCl, and Escherichia coli, a nonhalophilic eubacterium growing in 0.17 M NaCl. Magnesium and manganese contents varied with the growth phase, being maximal at the early log phase. Magnesium and manganese molalities in cell water were shown to increase with the halophilic character of the logarithmically growing bacteria, from 30 mmol of Mg per kg of cell water and 0.37 mmol of Mn per kg of cell water for E. coli to 102 mmol of Mg per kg of cell water and 1.6 mmol of Mn per kg of cell water for H cutirubrum. The intracellular concentrations of manganese were determined independently by a radioactive tracer technique in V. costicola and H. volcanii. The values obtained by 54 Mn loading represented about 70% of the values obtained by atomic absorption. The increase of magnesium and manganese contents associated with the halophilic character of the bacteria suggests that manganese and magnesium play a role in haloadaptation

  15. Fish skin bacteria: Colonial and cellular hydrophobicity. (United States)

    Sar, N; Rosenberg, E


    Bacteria were desorbed from the skin of healthy, fast-swimming fish by several procedures, including brief exposure to sonic oscillation and treatment with nontoxic surface active agents. The surface properties of these bacteria were studied by measuring their adhesion to hexadecane, as well as by a newly developed, simple method for studying the hydrophobicity of bacterial lawns. This method, referred to as the "Direction of Spreading" (DOS) method, consists of recording the direction to which a water drop spreads when introduced at the border between bacterial lawns and other surfaces. Of the 13 fish skin isolates examined, two strains were as hydrophobic as polystyrene by the DOS method. Suspended cells of one of these strains adhered strongly to hexadecane (84%), whereas cells of the other strain adhered poorly (13%). Another strain which was almost as hydrophobic as polystyrene by the DOS method did not adhere to hexadecane at all. Similarly, lawns of three other strains were more hydrophobic than glass by the DOS method, but cell suspensions prepared from these colonies showed little or no adhesion to hexadecane. The high colonial but relatively low cellular hydrophobicity could be due to a hydrophobic slime that is removed during the suspension and washing procedures. The possibility that specific bacteria assist in fish locomotion by changing the surface properties of the fish skin and by producing drag-reducing polymers is discussed.

  16. Engineering bacteria for enhanced polyhydroxyalkanoates (PHA biosynthesis

    Directory of Open Access Journals (Sweden)

    Guo-Qiang Chen


    Full Text Available Polyhydroxyalkanoates (PHA have been produced by some bacteria as bioplastics for many years. Yet their commercialization is still on the way. A few issues are related to the difficulty of PHA commercialization: namely, high cost and instabilities on molecular weights (Mw and structures, thus instability on thermo-mechanical properties. The high cost is the result of complicated bioprocessing associated with sterilization, low conversion of carbon substrates to PHA products, and slow growth of microorganisms as well as difficulty of downstream separation. Future engineering on PHA producing microorganisms should be focused on contamination resistant bacteria especially extremophiles, developments of engineering approaches for the extremophiles, increase on carbon substrates to PHA conversion and controlling Mw of PHA. The concept proof studies could still be conducted on E. coli or Pseudomonas spp. that are easily used for molecular manipulations. In this review, we will use E. coli and halophiles as examples to show how to engineer bacteria for enhanced PHA biosynthesis and for increasing PHA competitiveness.

  17. Contaminant bacteria in traditional-packed honey

    Directory of Open Access Journals (Sweden)

    Hening Tjaturina Pramesti


    Full Text Available Honey may be contaminated by microorganisms during its harvesting, processing, and packaging. Honey selected for clinical purposes must safe, sterile, and contain antimicrobial activity, so it must be evaluated using laboratory testing. The aim of this descriptive laboratory study was to isolate and identify the bacterial contaminant in the traditional-packed honey dealing with the use of honey for medical purposes. the colony forming units of honey sample cultured on blood agar were counted using Stuart bacterial colony counter. The suspected bacterial colonies were isolated and identified based on cultural morphology characteristics. The isolates of suspected bacterial colonies were stained according to Gram and Klein method and then were examined by the biochemical reaction. The results showed that there were two contaminant bacteria. Gram-positive cocci which were presumptively identified as coagulase-negative Staphylococci and gram-positive rods which were presumptively identified as Bacillus subtilis. In conclusion, the contaminant bacteria were regarded as low pathogen bacteria. The subtilin enzyme of B subtilis may cause an allergic reaction and coagulase-negative Staphylococci, Staphylococcus epidermidis is also an opportunist pathogen. Inevitably, for medical purposes, traditional-packed honey must be well filtered, water content above 18%, and standardized sterilization without loss of an antibacterial activity or change in properties.

  18. Excitons in intact cells of photosynthetic bacteria. (United States)

    Freiberg, Arvi; Pajusalu, Mihkel; Rätsep, Margus


    Live cells and regular crystals seem fundamentally incompatible. Still, effects characteristic to ideal crystals, such as coherent sharing of excitation, have been recently used in many studies to explain the behavior of several photosynthetic complexes, especially the inner workings of the light-harvesting apparatus of the oldest known photosynthetic organisms, the purple bacteria. To this date, there has been no concrete evidence that the same effects are instrumental in real living cells, leaving a possibility that this is an artifact of unnatural study conditions, not a real effect relevant to the biological operation of bacteria. Hereby, we demonstrate survival of collective coherent excitations (excitons) in intact cells of photosynthetic purple bacteria. This is done by using excitation anisotropy spectroscopy for tracking the temperature-dependent evolution of exciton bands in light-harvesting systems of increasing structural complexity. The temperature was gradually raised from 4.5 K to ambient temperature, and the complexity of the systems ranged from detergent-isolated complexes to complete bacterial cells. The results provide conclusive evidence that excitons are indeed one of the key elements contributing to the energetic and dynamic properties of photosynthetic organisms.

  19. NREL Scientists Model Methane-Eating Bacteria | News | NREL (United States)

    Scientists Model Methane-Eating Bacteria News Release: NREL Scientists Model Methane-Eating Bacteria February 13, 2018 Nature is full of surprises - not to mention solutions. A research team ) recently explored the possibilities provided by the natural world by researching how the bacteria

  20. Quantification and Qualification of Bacteria Trapped in Chewed Gum

    NARCIS (Netherlands)

    Wessel, Stefan W.; van der Mei, Henny C.; Morando, David; Slomp, Anje M.; van de Belt-Gritter, Betsy; Maitra, Amarnath; Busscher, Henk J.


    Chewing of gum contributes to the maintenance of oral health. Many oral diseases, including caries and periodontal disease, are caused by bacteria. However, it is unknown whether chewing of gum can remove bacteria from the oral cavity. Here, we hypothesize that chewing of gum can trap bacteria and

  1. Isolation and characterization of feather degrading bacteria from ...

    African Journals Online (AJOL)

    This study is aimed at isolating and characterizing new culturable feather degrading bacteria from soils of the University of Mauritius Farm. Bacteria that were isolated were tested for their capability to grow on feather meal agar (FMA). Proteolytic bacteria were tested for feather degradation and were further identified ...

  2. Bacteria associated with cultures of psathyrella atroumbonata (Pleger)

    African Journals Online (AJOL)

    These bacteria include Bacillus licheniformis, Bacillus subtilis, Leuconostoc mesenteroides, Pseudomonas aeruginosa, Bacillus cereus and Staphylococcus aureus. The average bacteria count was 1.0 x 106 cfu/ml and these bacteria grew within pH range of 5.0 and 9.0. the optimum temperature range of growth lied ...

  3. The growth of bacteria on organic compounds in drinking water

    NARCIS (Netherlands)

    Kooij, van der D.


    Growth ("regrowth") of bacteria In drinking water distribution systems results in a deterioration of the water quality. Regrowth of chemoheterotrophic bacteria depends on the presence of organic. compounds that serve as a nutrient source for these bacteria. A batch-culture technique was

  4. Bacteria associated with contamination of ready-to-eat (RTE ...

    African Journals Online (AJOL)

    The bacteria associated with contamination of ready-to-eat (RTE) cooked rice in Lagos, Nigeria were studied using standard microbiological methods. The objective of this study was to investigate the distribution of pathogenic bacteria recovered from RTE cooked rice in Lagos, assess bacteria load in the contaminated RTE ...

  5. Bacteria-Targeting Nanoparticles for Managing Infections (United States)

    Radovic-Moreno, Aleksandar Filip

    Bacterial infections continue to be a significant concern particularly in healthcare settings and in the developing world. Current challenges include the increasing spread of drug resistant (DR) organisms, the side effects of antibiotic therapy, the negative consequences of clearing the commensal bacterial flora, and difficulties in developing prophylactic vaccines. This thesis was an investigation of the potential of a class of polymeric nanoparticles (NP) to contribute to the management of bacterial infections. More specifically, steps were taken towards using these NPs (1) to achieve greater spatiotemporal control over drug therapy by more targeted antibiotic delivery to bacteria, and (2) to develop a prophylactic vaccine formulation against the common bacterial sexually transmitted disease (STD) caused by Chlamydia trachomatis. In the first part, we synthesized polymeric NPs containing poly(lactic-co-glycolic acid)-block-poly(L-histidine)-block-poly(ethylene glycol) (PLGA-PLH-PEG). We show that these NPs are able to bind to bacteria under model acidic infection conditions and are able to encapsulate and deliver vancomycin to inhibit the growth of Staphylococcus aureus bacteria in vitro. Further work showed that the PLGA-PLH-PEG-based NPs demonstrated the potential for competition for binding bacteria at a site of infection from soluble protein and model phagocytic and tissue-resident cells in a NP composition dependent manner. The NPs demonstrated low toxicity in vitro, were well tolerated by mice in vivo, and circulated in the blood on timescales comparable to control PLGA-PEG NPs. In the second part, we used PLGA-PLH-PEG-based NPs to design a prophylactic vaccine against the obligate intracellular bacterium Chlamydia trachomatis, the most common cause of bacterial STD in the world. Currently, no vaccines against this pathogen are approved for use in humans. We first formulated NPs encapsulating the TLR7 agonist R848 conjugated to poly(lactic acid) (R848-PLA

  6. Isolation and Presumptive Identification of Adherent Epithelial Bacteria (“Epimural” Bacteria) from the Ovine Rumen Wall


    Mead, Lorna J.; Jones, G. A.


    One hundred sixty-one strains of adherent bacteria were isolated under anaerobic conditions from four sites on the rumen epithelial surface of sheep fed hay or a hay-grain ration. Before isolation of bacteria, rumen tissue was washed six times in an anaerobic dilution solution, and viable bacteria suspended in the washings were counted. Calculation indicated that unattached bacteria would have been removed from the tissue by this procedure, but a slow and progressive release of attached bacte...

  7. Bacteria-Mineral Interactions on the Surfaces of Metal-Resistant Bacteria

    International Nuclear Information System (INIS)

    Malkin, A.J.


    The extraordinary ability of indigenous microorganisms, like metal-resistant bacteria, for biotransformation of toxic compounds is of considerable interest for the emerging area of environmental bioremediation. However, the underlying mechanisms by which metal-resistant bacteria transform toxic compounds are currently unknown and await elucidation. The project's objective was to study stress-induced responses of metal-resistant bacteria to environmental changes and chemical stimulants. This project involved a multi-institutional collaboration of our LLNL group with the group of Dr. H.-Y. Holman (Lawrence Berkeley National Laboratory). In this project, we have utilized metal-resistant bacteria Arthrobacter oxydans as a model bacterial system. We have utilized atomic force microscopy (AFM) to visualize for the first time at the nanometer scale formation of stress-induced structures on bacterial surfaces in response to Cr (VI) exposure. We have demonstrated that structure, assembly, and composition of these stress-induced structures are dependent on Cr (VI) concentrations. Our AFM observations of the appearance and development of stress-induced layers on the surfaces of Arthrobacter oxydans bacteria exposed to Cr (VI) were confirmed by Dr. Holman's biochemical, electron microscopy, and synchrotron infrared spectromicroscopy studies. In general, in vitro imaging of live microbial and cellular systems represents one of the most challenging issues in application of AFM. Various approaches for immobilization of bacteria on the substrate for in vitro imaging were tested in this project. Imaging of live bacteria was achieved, however further optimization of experimental methods are needed for high-resolution visualization of the cellular environmental structural dynamics by AFM. This project enhanced the current insight into molecular architecture, structural and environmental variability of bacterial systems. The project partially funded research for two book chapters (1

  8. Screening and characterization of phosphate solubilizing bacteria from isolate of thermophilic bacteria (United States)

    Yulianti, Evy; Rakhmawati, Anna


    The aims of this study were to select bacteria that has the ability to dissolve phosphate from thermophilic bacteria isolates after the Merapi eruption. Five isolates of selected bacteria was characterized and continued with identification. Selection was done by using a pikovskaya selective medium. Bacterial isolates were grown in selective medium and incubated for 48 hours at temperature of 55 ° C. Characterization was done by looking at the cell and colony morphology, physiological and biochemical properties. Identification was done with the Profile Matching method based on the reference genus Oscillospira traced through Bergey's Manual of Determinative Bacteriology. Dendogram was created based on similarity index SSM. The results showed there were 14 isolates of bacteria that were able to dissolve phosphate indicated by a clear zone surrounding the bacterial colony on selective media. Five isolates were selected with the largest clear zone. Isolates D79, D92, D110a, D135 and D75 have different characters. The result of phenotypic characters identification with Genus Oscillospira profile has a percentage of 100% similarity to isolate D92 and D110a; 92.31% for isolates D79, and 84.6% for isolates D75 and D135. Dendogram generated from average linkage algorithm / UPGMA using the Simple Matching Coefficient (SSM) algorithms showed, isolate thermophilic bacteria D75 and D135 are combined together to form cluster 1. D110a and D92 form a sub cluster A. Sub cluster A and D79 form cluster 2

  9. Probiotic bacteria: selective enumeration and survival in dairy foods. (United States)

    Shah, N P


    A number of health benefits have been claimed for probiotic bacteria such as Lactobacillus acidophilus, Bifidobacterium spp., and Lactobacillus casei. Because of the potential health benefits, these organisms are increasingly incorporated into dairy foods. However, studies have shown low viability of probiotics in market preparations. In order to assess viability of probiotic bacteria, it is important to have a working method for selective enumeration of these probiotic bacteria. Viability of probiotic bacteria is important in order to provide health benefits. Viability of probiotic bacteria can be improved by appropriate selection of acid and bile resistant strains, use of oxygen impermeable containers, two-step fermentation, micro-encapsulation, stress adaptation, incorporation of micronutrients such as peptides and amino acids and by sonication of yogurt bacteria. This review will cover selective enumeration and survival of probiotic bacteria in dairy foods.

  10. Ultrastructural analyses of platelets and fibrin networks in BALB/c mice after inhalation of spherical and rod-shaped titanium nanoparticles

    CSIR Research Space (South Africa)

    Oosthuizen, MA


    Full Text Available Engineered nanoparticles are designed to perform specific functions and therefore have specific properties that could potentially be harmful. Nanoparticles such as titanium dioxide have the potential to become transparent and are therefore widely...

  11. Ultrastructural analyses of platelets and fibrin networks in BALB/c mice after inhalation of spherical and rod-shaped titanium nanoparticles

    CSIR Research Space (South Africa)

    Oosthuizen, MA


    Full Text Available element in the earth?s crust, and TiO2 is allowed in food, drugs, cosmetics and contact lenses (Toxnet, 2007). Animal studies have shown no significant fibrosis, affected structure of air spaces in the lungs or irreversible tissue reaction... their classically known actions performed during thrombosis and haemostasis; and include the expression of adhesion molecules and contact-dependent activation of leucocytes, the release of a plethora of inflammatory mediators, activation in cells of the adaptive...

  12. Enterobacter siamensis sp. nov., a transglutaminase-producing bacterium isolated from seafood processing wastewater in Thailand. (United States)

    Khunthongpan, Suwannee; Bourneow, Chaiwut; H-Kittikun, Aran; Tanasupawat, Somboon; Benjakul, Soottawat; Sumpavapol, Punnanee


    A novel strain of Enterobacter, C2361(T), a Gram-negative, non-spore-forming, rod-shaped and facultative anaerobic bacterium with the capability to produce transglutaminase, was isolated from seafood processing wastewater collected from a treatment pond of a seafood factory in Songkhla Province, Thailand. Phylogenetic analyses and phenotypic characteristics, including chemotaxonomic characteristics, showed that the strain was a member of the genus Enterobacter. The 16S rRNA gene sequence similarities between strain C2361(T) and Enterobacter cloacae subsp. cloacae ATCC 13047(T) and Enterobacter cloacae subsp. dissolvens LMG 2683(T) were 97.5 and 97.5%, respectively. Strain C2361(T) showed a low DNA-DNA relatedness with the above-mentioned species. The major fatty acids were C16:0, C17:0cyclo and C14:0. The DNA G+C content was 53.0 mol%. On the basis of the polyphasic evidence gathered in this study, it should be classified as a novel species of the genus Enterobacter for which the name Enterobacter siamensis sp. nov. is proposed. The type strain is C2361(T) (= KCTC 23282(T) = NBRC 107138(T)).

  13. Acaricomes phytoseiuli gen. nov., sp. nov., isolated from the predatory mite Phytoseiulus persimilis. (United States)

    Pukall, Rüdiger; Schumann, Peter; Schütte, Conny; Gols, Rieta; Dicke, Marcel


    A Gram-positive, rod-shaped, non-spore-forming bacterium, strain CSCT, was isolated from diseased, surface-sterilized specimens of the predatory mite Phytoseiulus persimilis Athias-Henriot and subjected to polyphasic taxonomic analysis. Comparative analysis of the 16S rRNA gene sequence revealed that the strain was a new member of the family Micrococcaceae. Nearest phylogenetic neighbours were determined as Renibacterium salmoninarum (94.0%), Arthrobacter globiformis (94.8%) and Arthrobacter russicus (94.6%). Although the predominant fatty acids (anteiso C15:0), cell-wall sugars (galactose, glucose) and polar lipids (diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol) are in accordance with those of members of the genus Arthrobacter, strain CSCT can be distinguished from members of the genus Arthrobacter by biochemical tests, the absence of a rod-coccus life cycle and the occurrence of the partially saturated menaquinone MK-10(H2) as the predominant menaquinone. The DNA G+C content is 57.7 mol%. On the basis of morphological, chemotaxonomic and phylogenetic differences from other species of the Micrococcaceae, a novel genus and species are proposed, Acaricomes phytoseiuli gen. nov., sp. nov. The type strain is CSCT (=DSM 14247T=CCUG 49701T).

  14. Chryseobacterium formosense sp. nov., isolated from the rhizosphere of Lactuca sativa L. (garden lettuce). (United States)

    Young, Chiu-Chung; Kämpfer, Peter; Shen, Fo-Ting; Lai, Wei-An; Arun, A B


    A yellow-pigmented bacterial strain (CC-H3-2T), isolated from the rhizosphere of Lactuca sativa L. (garden lettuce) in Taiwan, was investigated using a polyphasic taxonomic approach. The cells were Gram-negative, rod-shaped and non-spore-forming. Phylogenetic analyses using the 16S rRNA gene sequence of the isolate indicated that the organism belongs to the genus Chryseobacterium, with the highest sequence similarity to the type strains of Chryseobacterium indoltheticum (97.7 %), Chryseobacterium scophthalmum (97.5 %), Chryseobacterium joostei (97.2 %) and Chryseobacterium defluvii (97.2 %). The major whole-cell fatty acids were iso-C(15 : 0) (52.2 %) and iso-C(17 : 0) 3-OH. DNA-DNA hybridization experiments revealed levels of only 27.4 % to C. scophthalmum, 27.1 % to C. indoltheticum, 14.1 % to C. joostei and 7.8 % to C. defluvii. DNA-DNA relatedness and biochemical and chemotaxonomic properties demonstrate that strain CC-H3-2T represents a novel species, for which the name Chryseobacterium formosense sp. nov. is proposed. The type strain is CC-H3-2T (=CCUG 49271T=CIP 108367T).

  15. Tsukamurella spongiae sp. nov., a novel actinomycete isolated from a deep-water marine sponge. (United States)

    Olson, Julie B; Harmody, Dedra K; Bej, Asim K; McCarthy, Peter J


    A Gram-positive, rod-shaped, non-spore-forming bacterium (strain K362(T)) was isolated from a deep-water marine sponge collected off the coast of Curaçao in the Netherlands Antilles. On the basis of 16S rRNA gene sequence similarities, strain K362(T) was shown to belong to the genus Tsukamurella, being most closely related to Tsukamurella pulmonis (99.2 %), Tsukamurella tyrosinosolvens (98.9 %), Tsukamurella strandjordii (98.8 %), Tsukamurella pseudospumae (98.8 %) and Tsukamurella spumae (98.8 %). A combination of the substrate utilization patterns, the fatty acid and mycolic acid profiles and the DNA-DNA hybridization results supported the affiliation of strain K362(T) to the genus Tsukamurella and enabled the genotypic and phenotypic differentiation of strain K362(T) from the seven recognized Tsukamurella species. Strain K362(T) therefore represents a novel species of the genus Tsukamurella, for which the name Tsukamurella spongiae sp. nov. is proposed. The type strain is K362(T) (=DSM 44990(T)=NRRL B-24467(T)).

  16. Aquimarina hainanensis sp. nov., isolated from diseased Pacific white shrimp Litopenaeus vannamei larvae. (United States)

    Zheng, Yanfen; Wang, Yanan; Liu, Yan; Li, Wentao; Yu, Mingchao; Zhang, Xiao-Hua


    One novel Gram-stain-negative, long rod-shaped, non-spore-forming, non-motile, non-flagellated and strictly aerobic strain, designated M124T, was isolated from diseased Pacific white shrimp Litopenaeus vannamei larvae. Growth occurred at 16-37 °C (optimum 28 °C), in the presence of 2-5 % (w/v) NaCl (optimum 3 %) and at pH 7-8 (optimum pH 7). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain M124T belonged to the genus Aquimarina and showed highest sequence similarity to Aquimarina penaei P3-1T (96.4 %). The dominant fatty acids of the isolate were iso-C15 : 0 and iso-C17 : 0 3-OH. The major polar lipids comprised phosphatidylethanolamine, one unknown aminolipid, three unknown phospholipids, two unknown glycolipids and one unknown polar lipid. The major respiratory quinone was menaquinone 6 (MK-6). The DNA G+C content of strain M124T was 33.7 mol%. Based on the polyphasic analyses in this study, strain M124T is considered to represent a novel species of the genus Aquimarina, for which the name Aquimarina hainanensis sp. nov. is proposed. The type strain is M124T ( = KCTC 42423T = MCCC 1K00498T).

  17. Proposal of Mucilaginibacter galii sp. nov. isolated from leaves of Galium album. (United States)

    Aydogan, Ebru L; Busse, Hans-Jürgen; Moser, Gerald; Müller, Christoph; Kämpfer, Peter; Glaeser, Stefanie P


    A pale-pink-pigmented, Gram-stain-negative, rod-shaped, non-spore-forming bacterial strain, PP-F2F-G47T, was isolated from the phyllosphere of the herbaceous plant Galium album. Phylogenetic analysis based on the nearly full-length 16S rRNA gene sequence revealed highest sequence similarity to the type strains of Mucilaginibacter daejeonensis (96.2 %), Mucilaginibacter dorajii (95.7 %) and Mucilaginibacter phyllosphaerae (95.5 %). 16S rRNA gene sequence similarities to all other type strains were below 95.5 %. The predominant cellular fatty acids of the strain were C16 : 1ω7c/iso-C15 : 0 2-OH (measured as summed feature 3) and iso-C15 : 0. The major compound in the polyamine pattern was sym-homospermidine and major quinone was menaquinone MK-7. The polar lipid profile was composed of phosphatidylethanolamine and several unidentified aminolipipids, phospholipids, aminophospholipids and lipids without a functional group. A sphingophospholipid could not be detected but a ninhydrin-positive alkaline-stable lipid was visible. The diagnostic diamino acid of the peptidoglycan was meso-diaminopimelic acid. Based on phylogenetic, chemotaxonomic and phenotypic analyses a novel species is proposed, Mucilaginibacter galii sp. nov., with PP-F2F-G47T (=CCM 8711T=CIP 111182T=LMG 29767T) as the type strain.

  18. Parapedobacter koreensis gen. nov., sp. nov. (United States)

    Kim, Myung Kyum; Na, Ju-Ryun; Cho, Dong Ha; Soung, Nak-Kyun; Yang, Deok-Chun


    Strain Jip14(T), a Gram-negative, non-spore-forming, rod-shaped, non-motile bacterium, was isolated from dried rice straw and characterized in order to determine its taxonomic position. 16S rRNA gene sequence analysis revealed that strain Jip14(T) belongs to the family Sphingobacteriaceae, and the highest degree of sequence similarity was determined to be to Pedobacter saltans DSM 12145(T) (88.5 %), Pedobacter africanus DSM 12126(T) (87.6 %), Pedobacter heparinus DSM 2366(T) (87.1 %) and Pedobacter caeni LMG 22862(T) (86.9 %). Chemotaxonomic data revealed that strain Jip14(T) possesses menaquinone MK-7 and the predominant fatty acids C(15 : 0) iso, C(16 : 0), C(16 : 0) 10-methyl, C(17 : 0) iso 3-OH and summed feature 3 (C(15 : 0) iso 2-OH/C(16 : 1)omega7c). The results of physiological and biochemical tests clearly demonstrated that strain Jip14(T) represents a distinct species. Based on these data, Jip14(T) should be classified within a novel genus and species, for which the name Parapedobacter koreensis gen. nov., sp. nov. is proposed. The type strain of Parapedobacter koreensis is Jip14(T) (=KCTC 12643(T)=LMG 23493(T)).

  19. Serratia bozhouensis sp. nov., Isolated from Sewage Samples of a Dairy Farm. (United States)

    Shang, Fei; Xue, Ting; Wang, Man; Chen, Xiaolin; Yu, Li; Zhang, Ming


    A Gram-negative, rod-shaped, salt-tolerant, non-pigmented, and non-spore-forming bacterium, designated strain W1 T (type strain CICC 23797 = CGMCC1.14949), was isolated from sewage samples of a dairy farm in Bozhou, Anhui, China. Strain W1 was resistant to lincomycin, troleandomycin, rifamycin, and vancomycin. Sequence analysis of the 16S rDNA gene revealed that the strain showed sequence similarity of 98.2% with the closest related species Serratia quinivorans CP6a T . The genomic DNA G+C content of the isolate was 52.8 mol%. The biochemical characteristics of strain W1 T assessed by the API 20E and Biolog GEN III analysis were different from those of the members of the genus Serratia. On the basis of the phenotypic and genotypic differences, strain W1 was proposed to be a novel Serratia species, Serratia bozhouensis sp. nov W1 T .

  20. Serratia ureilytica sp. nov., a novel urea-utilizing species. (United States)

    Bhadra, Bhaskar; Roy, Pradosh; Chakraborty, Ranadhir


    A Gram-negative, rod-shaped, urea-dissolving and non-spore-forming bacterium, designated strain NiVa 51(T), was isolated from water of the River Torsa in Hasimara, Jalpaiguri district, West Bengal, India. On the basis of 16S rRNA gene sequence similarity, strain NiVa 51(T) was shown to belong to the gamma-Proteobacteria and to be related to Serratia marcescens subsp. sakuensis (98.35%) and S. marcescens subsp. marcescens (98.30%); however, strain NiVa 51(T) exhibited only 43.7% similarity to S. marcescens by DNA-DNA hybridization. The G+C content of the genomic DNA of the isolate was 60 mol%. Both biochemical characteristics and fatty acid analysis data supported the affiliation of strain NiVa 51(T) to the genus Serratia. Furthermore, strain NiVa 51(T) was found to utilize urea as nitrogen source. The results of DNA-DNA hybridization as well as physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain NiVa 51(T) from recognized Serratia species. Strain NiVa 51(T) therefore represents a novel species, for which the name Serratia ureilytica sp. nov. is proposed, with type strain NiVa 51(T) (=LMG 22860(T)=CCUG 50595(T)).

  1. Isolation and identification of a bacterium from marine shrimp digestive tract: A new degrader of starch and protein (United States)

    Li, Jiqiu; Tan, Beiping; Mai, Kangsen


    It is a practical approach to select candidate probiotic bacterial stains on the basis of their special traits. Production of digestive enzyme was used as a trait to select a candidate probiotic bacterial strain in this study. In order to select a bacterium with the ability to degrade both starch and protein, an ideal bacterial strain STE was isolated from marine shrimp ( Litopenaeus vannamei) intestines by using multiple selective media. The selected isolate STE was identified on the basis of its morphological, physiological, and biochemical characteristics as well as molecular analyses. Results of degradation experiments confirmed the ability of the selected isolate to degrade both starch and casein. The isolate STE was aerobic, Gram-negative, rod-shaped, motile and non-spore-forming, and had catalase and oxidase activities but no glucose fermentation activity. Among the tested carbon/nitrogen sources, only Tween40, alanyl-glycine, aspartyl-glycine, and glycyl-l-glutamic acid were utilized by the isolate STE. Results of homology comparison analyses of the 16S rDNA sequences showed that the isolate STE had a high similarity to several Pseudoalteromonas species and, in the phylogenetic tree, grouped with P. ruthenica with maximum bootstrap support (100%). In conclusion, the isolate STE was characterized as a novel strain belonging to the genus Pseudoalteromonas. This study provides a further example of a probiotic bacterial strain with specific characteristics isolated from the host gastrointestinal tract.

  2. Introduce of Viable But Nonculturable Bacteria

    Directory of Open Access Journals (Sweden)

    Mehdi Hassanshahian


    Full Text Available Viable-But-Nonculturable-State (VBNC is the condition in which bacteria fail to grow on their routine bacteriological media where they would normally grow and develop into colonies, but are still alive and capable of renewed metabolic activity. VBNC state is useful for evaluating public health and for ascertaining the sterility of drinking water, pharmaceuticals, and foodstuff. A number of bacteria, mostly pathogenic to humans, have been proved to enter into this state in response to natural stresses such as starvation, incubation out of optimum growth temperature, increased osmotic pressure, etc. Once in the VBNC state, they undergo various physiological, structural, and genetic alterations. These alterations result in reduced cell size, conversion from bacilli to coccid, thickened cell walls, and peptidoglycan gaining many cross links. Metabolic changes also occur that include reductions in growth, nutrient transport, and respiratory rate; biosynthesis of new protein, and ATP remaining at a constant level. It has been shown that in the VBNC state, some pathogens conserve their virulence properties. Gene expression continues in the VBNC cell. Nucleic acids remain intact in the early VBNC phase but they gradually undergo degradation with prolonged VBNC. Cytological methods such as direct viable count and reduction of tetrazolium salts, and molecular methods such as reverse transcription polymerase chain reaction and green fluorescent protein have been used for the study of VBNC. Resuscitation from VBNC state starts when the inducing factor(s is/are lifted. Factors that help the resuscitation of VBNC bacteria include addition of certain nutrients and chemicals, introduction of a few culturable cells into the VBNC cell population, and passage through the animal host. As virulence properties are sustained during the VBNC phase, special care must be paid when evaluating sterility of drinking water.

  3. Catecholate siderophores protect bacteria from pyochelin toxicity.

    Directory of Open Access Journals (Sweden)

    Conrado Adler

    Full Text Available Bacteria produce small molecule iron chelators, known as siderophores, to facilitate the acquisition of iron from the environment. The synthesis of more than one siderophore and the production of multiple siderophore uptake systems by a single bacterial species are common place. The selective advantages conferred by the multiplicity of siderophore synthesis remains poorly understood. However, there is growing evidence suggesting that siderophores may have other physiological roles besides their involvement in iron acquisition.Here we provide the first report that pyochelin displays antibiotic activity against some bacterial strains. Observation of differential sensitivity to pyochelin against a panel of bacteria provided the first indications that catecholate siderophores, produced by some bacteria, may have roles other than iron acquisition. A pattern emerged where only those strains able to make catecholate-type siderophores were resistant to pyochelin. We were able to associate pyochelin resistance to catecholate production by showing that pyochelin-resistant Escherichia coli became sensitive when biosynthesis of its catecholate siderophore enterobactin was impaired. As expected, supplementation with enterobactin conferred pyochelin resistance to the entE mutant. We observed that pyochelin-induced growth inhibition was independent of iron availability and was prevented by addition of the reducing agent ascorbic acid or by anaerobic incubation. Addition of pyochelin to E. coli increased the levels of reactive oxygen species (ROS while addition of ascorbic acid or enterobactin reduced them. In contrast, addition of the carboxylate-type siderophore, citrate, did not prevent pyochelin-induced ROS increases and their associated toxicity.We have shown that the catecholate siderophore enterobactin protects E. coli against the toxic effects of pyochelin by reducing ROS. Thus, it appears that catecholate siderophores can behave as protectors of

  4. Repair by genetic recombination in bacteria: overview

    International Nuclear Information System (INIS)

    Howard-Flanders, P.


    DNA molecules that have been damaged in both strands at the same level are not subject to repair by excision but instead can be repaired through recombination with homologous molecules. Examples of two-strand damage include postreplication gaps opposite pyrimidine dimers, two-strand breaks produced by x-rays, and chemically induced interstrand cross-links. In ultraviolet-irradiated bacteria, and newly synthesized DNA is of length equal to the interdimer spacing. With continued incubation, this low-molecular-weight DNA is joined into high-molecular-weight chains (postreplication repair), a process associated with sister exchanges in bacteria. Recombination is initiated by pyrimidine dimers opposite postreplication gaps and by interstrand cross-links that have been cut by excision enzymes. The free ends at the resulting gaps presumably initiate the exchanges. Postreplication repair in Escherichia coli occurs in recB - and recC - but is greatly slowed in recF - mutants. RecB and recC are the structural genes for exonuclease V, which digests two-stranded DNA by releasing oligonucleotides first from one strand and then from the other. The postreplication sister exchanges in ultraviolet-irradiated bacteria result in the distribution of pyrimidine dimers between parental and daughter strands, indicating that long exchanges involving both strands of each duplex occur. The R1 restriction endonuclease from E. coli has been used to cut the DNA of a bacterial drug-resistance transfer factor with one nuclease-sensitive site, and also DNA from the frog Xenopus enriched for ribosomal 18S and 28S genes. The fragments were annealed with the cut plasmid DNA and ligated, producing a new larger plasmid carrying the eukaryotic rDNA and able to infect and replicate in E. coli

  5. Close Encounters of Lymphoid Cells and Bacteria (United States)

    Cruz-Adalia, Aranzazu; Veiga, Esteban


    During infections, the first reaction of the host against microbial pathogens is carried out by innate immune cells, which recognize conserved structures on pathogens, called pathogen-associated molecular patterns. Afterward, some of these innate cells can phagocytose and destroy the pathogens, secreting cytokines that would modulate the immune response to the challenge. This rapid response is normally followed by the adaptive immunity, more specific and essential for a complete pathogen clearance in many cases. Some innate immune cells, usually named antigen-presenting cells, such as macrophages or dendritic cells, are able to process internalized invaders and present their antigens to lymphocytes, triggering the adaptive immune response. Nevertheless, the traditional boundary of separated roles between innate and adaptive immunity has been blurred by several studies, showing that very specialized populations of lymphocytes (cells of the adaptive immunity) behave similarly to cells of the innate immunity. These “innate-like” lymphocytes include γδ T cells, invariant NKT cells, B-1 cells, mucosal-associated invariant T cells, marginal zone B cells, and innate response activator cells, and together with the newly described innate lymphoid cells are able to rapidly respond to bacterial infections. Strikingly, our recent data suggest that conventional CD4+ T cells, the paradigm of cells of the adaptive immunity, also present innate-like behavior, capturing bacteria in a process called transinfection. Transinfected CD4+ T cells digest internalized bacteria like professional phagocytes and secrete large amounts of proinflammatory cytokines, protecting for further bacterial challenges. In the present review, we will focus on the data showing such innate-like behavior of lymphocytes following bacteria encounter. PMID:27774092

  6. Electroactive biofilms of sulphate reducing bacteria

    International Nuclear Information System (INIS)

    Cordas, Cristina M.; Guerra, L. Tiago; Xavier, Catarina; Moura, Jose J.G.


    Biofilms formed from a pure strain of Desulfovibrio desulfuricans 27774 on stainless steel and graphite polarised surfaces were studied. The polarisation conditions applied were -0.4 V vs. SCE for different times. A cathodic current related with the biofilms growth was observed with a maximum intensity of -270 mA m -2 that remained stable for several days using graphite electrodes. These sulphate reducing bacteria biofilms present electrocatalytic activity towards hydrogen and oxygen reduction reactions. Electrode polarisation has a selective effect on the catalytic activity. The biofilms were also observed by scanning electronic microscopy revealing the formation of homogeneous films on the surfaces

  7. Bioluminescent bacteria: lux genes as environmental biosensors

    Directory of Open Access Journals (Sweden)

    Nunes-Halldorson Vânia da Silva


    Full Text Available Bioluminescent bacteria are widespread in natural environments. Over the years, many researchers have been studying the physiology, biochemistry and genetic control of bacterial bioluminescence. These discoveries have revolutionized the area of Environmental Microbiology through the use of luminescent genes as biosensors for environmental studies. This paper will review the chronology of scientific discoveries on bacterial bioluminescence and the current applications of bioluminescence in environmental studies, with special emphasis on the Microtox toxicity bioassay. Also, the general ecological significance of bioluminescence will be addressed.

  8. Polymorphic transformation of helical flagella of bacteria (United States)

    Lim, Sookkyung; Howard Berg Collaboration; William Ko Collaboration; Yongsam Kim Collaboration; Wanho Lee Collaboration; Charles Peskin Collaboration


    Bacteria such as E. coli swim in an aqueous environment by utilizing the rotation of flagellar motors and alternate two modes of motility, runs and tumbles. Runs are steady forward swimming driven by bundles of flagellar filaments whose motors are turning CCW; tumbles involve a reorientation of the direction of swimming triggered by motor reversals. During tumbling, the helical flagellum undergoes polymorphic transformations, which is a local change in helical pitch, helical radius, and handedness. In this work, we investigate the underlying mechanism of structural conformation and how this polymorphic transition plays a role in bacterial swimming. National Science Foundation.

  9. Ethylene-producing bacteria that ripen fruit. (United States)

    Digiacomo, Fabio; Girelli, Gabriele; Aor, Bruno; Marchioretti, Caterina; Pedrotti, Michele; Perli, Thomas; Tonon, Emil; Valentini, Viola; Avi, Damiano; Ferrentino, Giovanna; Dorigato, Andrea; Torre, Paola; Jousson, Olivier; Mansy, Sheref S; Del Bianco, Cristina


    Ethylene is a plant hormone widely used to ripen fruit. However, the synthesis, handling, and storage of ethylene are environmentally harmful and dangerous. We engineered E. coli to produce ethylene through the activity of the ethylene-forming enzyme (EFE) from Pseudomonas syringae. EFE converts a citric acid cycle intermediate, 2-oxoglutarate, to ethylene in a single step. The production of ethylene was placed under the control of arabinose and blue light responsive regulatory systems. The resulting bacteria were capable of accelerating the ripening of tomatoes, kiwifruit, and apples.

  10. Are Bacteria more dangerous in space?

    International Nuclear Information System (INIS)

    Leys, N.; Baatout, S.


    With a mission to Mars and a permanent base on the moon as the ultimate dream, space travel is continually pushing back the frontiers. But long space missions present great challenges for science, for example in the field of microbiology. Together with the European Space Agency (ESA), SCK-CEN is studying the effects of space travel conditions on the behaviour of bacteria. In 2009 the SCK-CEN experts completed four innovative research projects at the cutting edge of microbiology, radiation sciences and space travel.

  11. Electroactive biofilms of sulphate reducing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Cordas, Cristina M.; Guerra, L. Tiago; Xavier, Catarina [Requimte-CQFB, Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Moura, Jose J.G. [Requimte-CQFB, Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal)], E-mail:


    Biofilms formed from a pure strain of Desulfovibrio desulfuricans 27774 on stainless steel and graphite polarised surfaces were studied. The polarisation conditions applied were -0.4 V vs. SCE for different times. A cathodic current related with the biofilms growth was observed with a maximum intensity of -270 mA m{sup -2} that remained stable for several days using graphite electrodes. These sulphate reducing bacteria biofilms present electrocatalytic activity towards hydrogen and oxygen reduction reactions. Electrode polarisation has a selective effect on the catalytic activity. The biofilms were also observed by scanning electronic microscopy revealing the formation of homogeneous films on the surfaces.

  12. Bacteria-Triggered Release of Antimicrobial Agents

    DEFF Research Database (Denmark)

    Komnatnyy, Vitaly V.; Chiang, Wen-Chi; Tolker-Nielsen, Tim


    Medical devices employed in healthcare practice are often susceptible to microbial contamination. Pathogenic bacteria may attach themselves to device surfaces of catheters or implants by formation of chemically complex biofilms, which may be the direct cause of device failure. Extracellular...... bacterial lipases are particularly abundant at sites of infection. Herein it is shown how active or proactive compounds attached to polymeric surfaces using lipase‐sensitive linkages, such as fatty acid esters or anhydrides, may be released in response to infection. Proof‐of‐concept of the responsive...

  13. Anaerobic bacteria as producers of antibiotics. (United States)

    Behnken, Swantje; Hertweck, Christian


    Anaerobic bacteria are the oldest terrestrial creatures. They occur ubiquitously in soil and in the intestine of higher organisms and play a major role in human health, ecology, and industry. However, until lately no antibiotic or any other secondary metabolite has been known from anaerobes. Mining the genome sequences of Clostridium spp. has revealed a high prevalence of putative biosynthesis genes (PKS and NRPS), and only recently the first antibiotic from the anaerobic world, closthioamide, has been isolated from the cellulose degrading bacterium Clostridium cellulolyticum. The successful genetic induction of antibiotic biosynthesis in an anaerobe encourages further investigations of obligate anaerobes to tap their hidden biosynthetic potential.

  14. Bacteria in atmospheric waters: Detection, characteristics and implications (United States)

    Hu, Wei; Niu, Hongya; Murata, Kotaro; Wu, Zhijun; Hu, Min; Kojima, Tomoko; Zhang, Daizhou


    In this review paper, we synthesize the current knowledges about bacteria in atmospheric waters, e.g., cloud, fog, rain, and snow, most of which were obtained very recently. First, we briefly describe the importance of bacteria in atmospheric waters, i.e., the essentiality of studying bacteria in atmospheric waters in understanding aerosol-cloud-precipitation-climate interactions in the Earth system. Next, approaches to collect atmospheric water samples for the detection of bacteria and methods to identify the bacteria are summarized and compared. Then the available data on the abundance, viability and community composition of bacteria in atmospheric waters are summarized. The average bacterial concentration in cloud water was usually on the order 104-105 cells mL-1, while that in precipitation on the order 103-104 cells mL-1. Most of the bacteria were viable or metabolically active. Their community composition was highly diverse and differed at various sites. Factors potentially influencing the bacteria, e.g., air pollution levels and sources, meteorological conditions, seasonal effect, and physicochemical properties of atmospheric waters, are described. After that, the implications of bacteria present in atmospheric waters, including their effect on nucleation in clouds, atmospheric chemistry, ecosystems and public health, are briefly discussed. Finally, based on the current knowledges on bacteria in atmospheric waters, which in fact remains largely unknown, we give perspectives that should be paid attention to in future studies.

  15. The effect of lactic acid bacteria on cocoa bean fermentation. (United States)

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


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

  16. Metabolism of polychlorinated biphenyls by marine bacteria

    International Nuclear Information System (INIS)

    Carey, A.E.; Harvey, G.R.


    There have been no reports of laboratory studies of PCB metabolism by marine organisms. A few workers have analyzed marine animals for products of PCB metabolism. A search for hydroxylated PCBs in marine fish proved inconclusive. Phenolic metabolites of PCBs have been identified in seals and guillemot. PCBs that had been hydroxylated and excreted by marine organisms would most likely be found in the sediments, so in our laboratory we conducted a search for these compounds in marine sediments. Two kilograms of organic-rich surface sediment from Buzzards Bay, Massachusetts, were extracted. The phenolic fraction was isolated and analyzed by gas chromatography-mass spectrometry (GC-MS). Neither wide mass scans nor selected mass searches produced any evidence of hydroxylated PCB derivatives. It was felt that if any marine organisms were capable of metabolism of PCBs, some marine bacteria should have that capability. Thus a series of laboratory experiments was conducted to test this possibility. Reported here is the finding of PCB metabolism by marine bacteria in batch culture

  17. Long-term preservation of anammox bacteria. (United States)

    Rothrock, Michael J; Vanotti, Matias B; Szögi, Ariel A; Gonzalez, Maria Cruz Garcia; Fujii, Takao


    Deposit of useful microorganisms in culture collections requires long-term preservation and successful reactivation techniques. The goal of this study was to develop a simple preservation protocol for the long-term storage and reactivation of the anammox biomass. To achieve this, anammox biomass was frozen or lyophilized at two different freezing temperatures (-60°C and in liquid nitrogen (-200°C)) in skim milk media (with and without glycerol), and the reactivation of anammox activity was monitored after a 4-month storage period. Of the different preservation treatments tested, only anammox biomass preserved via freezing in liquid nitrogen followed by lyophilization in skim milk media without glycerol achieved stoichiometric ratios for the anammox reaction similar to the biomass in both the parent bioreactor and in the freshly harvested control treatment. A freezing temperature of -60°C alone, or in conjunction with lyophilization, resulted in the partial recovery of the anammox bacteria, with an equal mixture of anammox and nitrifying bacteria in the reactivated biomass. To our knowledge, this is the first report of the successful reactivation of anammox biomass preserved via sub-zero freezing and/or lyophilization. The simple preservation protocol developed from this study could be beneficial to accelerate the integration of anammox-based processes into current treatment systems through a highly efficient starting anammox biomass.

  18. Bioactivation of Phytoestrogens: Intestinal Bacteria and Health. (United States)

    Landete, J M; Arqués, J; Medina, M; Gaya, P; de Las Rivas, B; Muñoz, R


    Phytoestrogens are polyphenols similar to human estrogens found in plants or derived from plant precursors. Phytoestrogens are found in high concentration in soya, flaxseed and other seeds, fruits, vegetables, cereals, tea, chocolate, etc. They comprise several classes of chemical compounds (stilbenes, coumestans, isoflavones, ellagitannins, and lignans) which are structurally similar to endogenous estrogens but which can have both estrogenic and antiestrogenic effects. Although epidemiological and experimental evidence indicates that intake of phytoestrogens in foods may be protective against certain chronic diseases, discrepancies have been observed between in vivo and in vitro experiments. The microbial transformations have not been reported so far in stilbenes and coumestans. However, isoflavones, ellagitanins, and lignans are metabolized by intestinal bacteria to produce equol, urolithins, and enterolignans, respectively. Equol, urolithin, and enterolignans are more bioavailable, and have more estrogenic/antiestrogenic and antioxidant activity than their precursors. Moreover, equol, urolithins and enterolignans have anti-inflammatory effects and induce antiproliferative and apoptosis-inducing activities. The transformation of isoflavones, ellagitanins, and lignans by intestinal microbiota is essential to be protective against certain chronic diseases, as cancer, cardiovascular disease, osteoporosis, and menopausal symptoms. Bioavailability, bioactivity, and health effects of dietary phytoestrogens are strongly determined by the intestinal bacteria of each individual.

  19. Inoculation of sugarcane with diazotrophic bacteria

    Directory of Open Access Journals (Sweden)

    Nivaldo Schultz


    Full Text Available The sugarcane industry, a strategic crop in Brazil, requires technological improvements in production efficiency to increase the crop energy balance. Among the various currently studied alternatives, inoculation with diazotrophic bacteria proved to be a technology with great potential. In this context, the efficiency of a mixture of bacterial inoculant was evaluated with regard to the agronomic performance and N nutrition of sugarcane. The experiment was carried out on an experimental field of Embrapa Agrobiologia, in Seropédica, Rio de Janeiro, using a randomized block, 2 × 3 factorial design (two varieties and three treatments with four replications, totaling 24 plots. The varieties RB867515 and RB72454 were tested in treatments consisting of: inoculation with diazotrophic bacteria, N-fertilized control with 120 kg ha-1 N and absolute control (no inoculation and no N fertilizer. The inoculum was composed of five strains of five diazotrophic species. The yield, dry matter accumulation, total N in the shoot dry matter and the contribution of N by biological fixation were evaluated, using the natural 15N abundance in non-inoculated sugarcane as reference. The bacterial inoculant increased the stalk yield of variety RB72454 similarly to fertilization with 120 kg ha-1 N in the harvests of plant-cane and first ratoon crops, however the contribution of biological N fixation was unchanged by inoculation, indicating that the benefits of the inoculant in sugarcane may have resulted from plant growth promotion.

  20. Beneficial effects of antioxidative lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Hisako Nakagawa


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

  1. Starvation-survival of subsurface bacteria

    International Nuclear Information System (INIS)

    Magill, N.G.


    The ability of four subsurface isolates to survive starvation was examined and the results were compared to survival curves obtained for Escherichia coli B and Serratia marcescens. To examine the starvation-survival phenomenon further, several experimental parameters including nutritional history, initial cell density, growth phase, temperature of growth and starvation, and aeration. Nutritional history, initial cell density, and growth phases of the cells had some effect on the ability of these bacteria to survive whereas temperature and limited aeration had no effect under the conditions tested. No conditions were found where E. coli B or Serratia marcescens died rapidly or where less than 10% of the original cell number of viable cells remained. Because the apparent survival of these bacteria may be due to cryptic growth, cross-feeding experiments with 14 C-labeled cells and unlabeled cells were carried out with E. coli B and Pseudomonas Lula V. Leaked extracellular 14 C-compounds were not used for growth or maintenance energy, and were not taken up by either bacterium. Cryptic growth did not occur; the cells were truly starving under the experimental conditions used

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

    Directory of Open Access Journals (Sweden)

    Beata Nalepa


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

  3. Sulphur bacteria mediated formation of Palaeoproterozoic phosphorites (United States)

    Joosu, Lauri; Lepland, Aivo; Kirsimäe, Kalle


    Modern phosphorite formation is typically associated with high productivity in upwelling areas where apatite (Ca-phosphate) precipitation is mediated by sulphur oxidising bacteria [1]. They inhabit the oxic/anoxic interface within the upper few centimetres of sediment column, accumulating phosphate in their cells under oxic conditions and releasing it rapidly when conditions become anoxic. Sulphur bacteria are known to live in close association with a consortium of anaerobic methane oxidising archaea and syntrophic sulphate-reducing bacteria. Paleoproterozoic, c. 2.0 Ga Zaonega Formation in Karelia, Russia contains several P-rich intervals in the upper part of 1500 m thick succession of organic-rich sedimentary rocks interlayered with mafic tuffs and lavas. Apatite in these P-rich intervals forms impure laminae, lenses and round-oval nodules which diameters typically range from 300 to 1000 μm. Individual apatite particles in P-rich laminae and nodules commonly occur as cylinders that are 1-8 μm long and have diameters of 0.5-4 μm. Cross-sections of best preserved cylindrical apatite particles reveal a thin outer rim whereas the internal parts consist of small anhedral elongated crystallites, intergrown with carbonaceous material. During recrystallization the outer rim thickens towards interior and cylinders may attain hexagonal crystal habit, but their size and shape remains largely unchanged [2]. The sizes of Zaonega nodules are similar to giant sulphide-oxidising bacteria known from modern and ancient settings [3, 4]. Individual apatite cylinders and aggregates have shapes and sizes similar to the methanotrophic archaea that inhabit microbial mats in modern seep/vent areas where they operate in close associations with sulphur-oxidising microbial communities [5]. Seep/vent influence during the Zaonega phosphogenesis is indicated by variable, though positive Eu anomaly, expected in magmatically active sedimentary environment experiencing several lava flows

  4. Experimental Study of Bacterial Penetration into Chalk Rock: Mechanisms and Effect on Permeability

    DEFF Research Database (Denmark)

    Halim, Amalia Yunita; Shapiro, Alexander; Eliasson Lantz, Anna


    Bacterial selective plugging is one of the mechanisms through which microorganisms can be applied for enhanced oil recovery, as bacteria can plug the water-swept zones of a reservoir, thus altering the flow paths and improving sweep efficiency. However, complete understanding of the penetration...... behavior of bacteria is lacking, especially in chalk formations where characteristic pore throat sizes are comparable with the sizes of bacterial cells. In this study, two bacterial strains, Bacillus licheniformis 421 (spore-forming) and Pseudomonas putida K12 (non-spore forming) were used to investigate...... the penetration of bacteria into chalk and its effect on permeability reduction. The core plugs were produced from Stevns Klint outcrop with low permeability (2–4 mD) and with pore sizes comparable to bacterial sizes. Both types of bacteria were able to penetrate and to be transported through the cores to some...

  5. Antibacterial Activities of Endophytic Bacteria Isolated from Taxus brevifolia Against Foodborne Pathogenic Bacteria. (United States)

    Islam, Nurul; Choi, Jaehyuk; Baek, Kwang-Hyun


    Endophytes are a potential source of novel bioactive compounds with medicinal properties. In this study, 41 endophytic bacteria (EB) were isolated from tissues of a medicinally important plant Taxus brevifolia (Pacific yew). The objective was to screen all the EB isolates for their antibacterial effects against five foodborne pathogenic bacteria: Bacillus cereus ATCC10876, Staphylococcus aureus ATCC12600, Listeria monocytogenes ATCC19115, Escherichia coli ATCC43890, and Salmonella Typhimurium ATCC19585. Among the EB isolates, T. brevifolia seed (TbS)-8, T. brevifolia fleshy part of fruit (TbFl)-10, T. brevifolia leaf (TbL)-22, TbS-29, and TbL-34 exerted significant antibacterial activity against the tested foodborne pathogens. Especially TbFl-10 showed the highest antibacterial activity against all the tested bacteria and was identified as Paenibacillus kribbensis (Pk). Furthermore, an ethyl acetate extract of Pk-TbFl-10 possessed antibacterial activities against the tested five foodborne pathogenic bacteria, with zones of inhibition from 15.71 ± 2.85 to 13.01 ± 2.12 mm. Scanning electron microscopy analysis revealed ruptured, lysed, shrunk, and swollen cells of all the tested foodborne pathogens treated with the ethyl acetate extract of Pk-TbFl-10, suggesting that a metabolite(s) of Pk-TbFl-10 penetrates the cell membrane and causes cell lysis leading to cell death. Our results indicate that Pk-TbFl-10 isolated from T. brevifolia can serve as a novel source of natural antibacterial agents against foodborne pathogenic bacteria, with potential applications in the pharmaceutical industry.

  6. [Effects of transgenic Bt + CpTI cotton on rhizosphere bacteria and ammonia oxidizing bacteria population]. (United States)

    Dong, Lianhua; Meng, Ying; Wang, Jing


    The effect of transgenic cotton on the rhizosphere bacteria can be important to the risk assessment for the genetically modified crops. We studied the rhizosphere microbial community with cultivating genetically modified cotton. The effects of transgenic Bt + CpTI Cotton (SGK321) and its receptor cotton (SY321) on rhizosphere total bacteria and ammonia oxidizing bacteria population size were studied by using droplet digital PCR. We collected rhizosphere soil before cotton planting and along with the cotton growth stage (squaring stage, flowering stage, belling stage and boll opening stage). There was no significant change on the total bacterial population between the transgenic cotton and the receptor cotton along with the growth stage. However, the abundance of ammonia oxidizing bacteria (AOB) in both type of cottons showed significant difference between different growth stages, and the variation tendency was different. In squaring stage, the numbers of AOB in rhizosphere of SY321 and SGK321 increased 4 and 2 times, respectively. In flowering stage, AOB number in rhizosphere of SY321 significantly decreased to be 5.96 x 10(5) copies/g dry soil, however, that of SGK321 increased to be 1.25 x 10(6) copies/g dry soil. In belling stage, AOB number of SY321 greatly increased to be 1.49 x 10(6) copies/g dry soil, but no significant change was observed for AOB number of SGK321. In boll opening stage, both AOB number of SY321 and SGK321 clearly decreased and they were significantly different from each other. Compared to the non-genetically modified cotton, the change in abundance of ammonia oxidizing bacteria was slightly smooth in the transgenic cotton. Not only the cotton growth stage but also the cotton type caused this difference. The transgenic cotton can slow down the speed of ammonia transformation through impacting the number of AOB, which is advantageous for plant growth.

  7. Reactivity of the Bacteria-Water Interface: Linking Nutrient Availability to Bacteria-Metal Interactions (United States)

    Fowle, D. A.; Daughney, C. J.; Riley, J. L.


    Identifying and quantifying the controls on metal mobilities in geologic systems is critical in order to understand processes such as global element cycling, metal transport in near-surface water-rock systems, sedimentary diagenesis, and mineral formation. Bacteria are ubiquitous in near-surface water-rock systems, and numerous laboratory and field studies have demonstrated that bacteria can facilitate the formation and dissolution of minerals, and enhance or inhibit contaminant transport. However, despite the growing evidence that bacteria play a key role in many geologic processes in low temperature systems, our understanding of the influence of the local nutrient dynamics of the system of interest on bacteria-metal interactions is limited. Here we present data demonstrating the effectiveness of coupling laboratory experiments with geochemical modeling to isolate the effect of nutrient availability on bacterially mediated proton and metal adsorption reactions. Experimental studies of metal-bacteria interactions were conducted in batch reactors as a function of pH, and solid-solute interactions after growth in a variety of defined and undefined media. Media nutrient composition (C,N,P) was quantified before and after harvesting the cells. Surface complexation models (SCM) for the adsorption reactions were developed by combining sorption data with the results of acid-base titrations, and in some cases zeta potential titrations of the bacterial surface. Our results indicate a clear change in both buffering potential and metal binding capacity of the cell walls of Bacillus subtilis as a function of initial media conditions. Combining current studies with our past studies on the effects of growth phase and others work on temperature dependence on metal adsorption we hope to develop a holistic surface complexation model for quantifying bacterial effects on metal mass transfer in many geologic systems.

  8. Reducing gas content of coal deposits by means of bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Godlewska-Lipowa, A A; Kozlowski, B


    This paper discusses the results of experiments carried out in Poland under laboratory conditions on efficiency of methane control using bacteria from Methanosarcina and Methanomonas groups. Malashenko and Whittenburry culture mediums were used. Bacteria growth in an atmosphere of air and methane (48.2%, 8.6% and 5.21%) was observed. Temperature ranged from 19 to 20 C. Investigations show that the bacteria are characterized by high oxidation activity. Depending on methane concentration in the air the bacteria consume from 75% to 100% of methane during biosynthesis. The bacteria reduce methane and oxygen content and increase carbon dioxide content in the air. Using bacteria methane concentration in the air was reduced from 48.2% to 12.3%, from 8.6% to 0.0% and from 5.21% to 0.01%. (7 refs.) (In Polish)

  9. Influence of irradiation of bacteria on their thermoresistance

    International Nuclear Information System (INIS)

    Szulc, M.; Stefaniakowa, A.; Tropilo, J.; Stanczak, B.; Peconek, J.; Mierzewska, H.; Bielecka, J.


    The influence of x-radiation on thermoresistance of bacteria was determined. The studies were carried out on: E. coli, Pr. vulgaris, S. typhimurium, Staph. aureus and Str. faecalis. The bacteria were irradiated in PBS (physiological buffer solution) and in broth (containing about 1% of protein) with x-rays at radium absorbed doses of 100, 1000, 5000 and 10 000, which was followed immediately by heating at temperatures causing death of part of the bacteria. The results obtained indicate that irradiation of bacteria with small x-ray doses distinctly decreases their thermoresistance. Synergetic action of irradiation and heating of bacteria was observed, increasing with increased irradiation dose. The greatest changes of thermoresistance occurred with Pr. vulgaris, the smallest with S. typhimurium. Thermoresistance of bacteria decreased more strongly on their irradiation in protein-free medium (PBS). (author)

  10. Deployable micro-traps to sequester motile bacteria (United States)

    di Giacomo, Raffaele; Krödel, Sebastian; Maresca, Bruno; Benzoni, Patrizia; Rusconi, Roberto; Stocker, Roman; Daraio, Chiara


    The development of strategies to reduce the load of unwanted bacteria is a fundamental challenge in industrial processing, environmental sciences and medical applications. Here, we report a new method to sequester motile bacteria from a liquid, based on passive, deployable micro-traps that confine bacteria using micro-funnels that open into trapping chambers. Even in low concentrations, micro-traps afford a 70% reduction in the amount of bacteria in a liquid sample, with a potential to reach >90% as shown by modelling improved geometries. This work introduces a new approach to contain the growth of bacteria without chemical means, an advantage of particular importance given the alarming growth of pan-drug-resistant bacteria.

  11. Biotechnological applications of acetic acid bacteria. (United States)

    Raspor, Peter; Goranovic, Dusan


    The acetic acid bacteria (AAB) have important roles in food and beverage production, as well as in the bioproduction of industrial chemicals. In recent years, there have been major advances in understanding their taxonomy, molecular biology, and physiology, and in methods for their isolation and identification. AAB are obligate aerobes that oxidize sugars, sugar alcohols, and ethanol with the production of acetic acid as the major end product. This special type of metabolism differentiates them from all other bacteria. Recently, the AAB taxonomy has been strongly rearranged as new techniques using 16S rRNA sequence analysis have been introduced. Currently, the AAB are classified in ten genera in the family Acetobacteriaceae. AAB can not only play a positive role in the production of selected foods and beverages, but they can also spoil other foods and beverages. AAB occur in sugar- and alcohol-enriched environments. The difficulty of cultivation of AAB on semisolid media in the past resulted in poor knowledge of the species present in industrial processes. The first step of acetic acid production is the conversion of ethanol from a carbohydrate carried out by yeasts, and the second step is the oxidation of ethanol to acetic acid carried out by AAB. Vinegar is traditionally the product of acetous fermentation of natural alcoholic substrates. Depending on the substrate, vinegars can be classified as fruit, starch, or spirit substrate vinegars. Although a variety of bacteria can produce acetic acid, mostly members of Acetobacter, Gluconacetobacter, and Gluconobacter are used commercially. Industrial vinegar manufacturing processes fall into three main categories: slow processes, quick processes, and submerged processes. AAB also play an important role in cocoa production, which represents a significant means of income for some countries. Microbial cellulose, produced by AAB, possesses some excellent physical properties and has potential for many applications. Other

  12. Transmission of Nephridial Bacteria of the Earthworm Eisenia fetida


    Davidson, Seana K.; Stahl, David A.


    The lumbricid earthworms (annelid family Lumbricidae) harbor gram-negative bacteria in their excretory organs, the nephridia. Comparative 16S rRNA gene sequencing of bacteria associated with the nephridia of several earthworm species has shown that each species of worm harbors a distinct bacterial species and that the bacteria from different species form a monophyletic cluster within the genus Acidovorax, suggesting that there is a specific association resulting from radiation from a common b...

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


    Brooijmans, Rob; Smit, Bart; Santos, Filipe; van Riel, Jan; de Vos, Willem M; Hugenholtz, Jeroen


    Abstract Background For some lactic acid bacteria higher biomass production as a result of aerobic respiration has been reported upon supplementation with heme and menaquinone. In this report, we have studied a large number of species among lactic acid bacteria for the existence of this trait. Results Heme- (and menaquinone) stimulated aerobic growth was observed for several species and genera of lactic acid bacteria. These include Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacill...

  14. Biodegradation of endosulfan by mixed bacteria culture strains of ...

    African Journals Online (AJOL)

    Biodegradation of endosulfan by mixed bacteria culture strains of Pseudomonas aeruginosa and Staphylococcus aureus. Nsidibeabasi Calvin Nwokem, Calvin Onyedika Nwokem, Casmir Emmanuel Gimba, Beatrice Nkiruka Iwuala ...

  15. Effect of radiation on activity of sulphate reducing bacteria

    International Nuclear Information System (INIS)

    Agaev, N.M.; Smorodin, A.E.; Gusejnov, M.M.


    The effect of γ-radiation on activity of sulphate reducing bacteria has been studied. Concentration of biogenic hydrogen, generated in the medium, is the main criterion, characterizing corrosion activity of the bacteria studied. The developed method of suppression of active development of sulfate reducing bacteria considerably reduces, and at lethal doses of γ-radiation eliminates altogether the bacteria activity and formation of the main corrosion agent-hydrogen sulphide-in the medium and that, in its turn, liquidates hydrogen sulphide corrosion

  16. Characterization of Bacteria Associated with Pinewood Nematode Bursaphelenchus xylophilus (United States)

    Vicente, Claudia S. L.; Nascimento, Francisco; Espada, Margarida; Barbosa, Pedro; Mota, Manuel; Glick, Bernard R.; Oliveira, Solange


    Pine wilt disease (PWD) is a complex disease integrating three major agents: the pathogenic agent, the pinewood nematode Bursaphelenchus xylophilus; the insect-vector Monochamus spp.; and the host pine tree, Pinus sp. Since the early 80's, the notion that another pathogenic agent, namely bacteria, may play a role in PWD has been gaining traction, however the role of bacteria in PWD is still unknown. The present work supports the possibility that some B. xylophilus-associated bacteria may play a significant role in the development of this disease. This is inferred as a consequence of: (i) the phenotypic characterization of a collection of 35 isolates of B. xylophilus-associated bacteria, in different tests broadly used to test plant pathogenic and plant growth promoting bacteria, and (ii) greenhouse experiments that infer the pathogenicity of these bacteria in maritime pine, Pinus pinaster. The results illustrate the presence of a heterogeneous microbial community associated with B. xylophilus and the traits exhibited by at least, some of these bacteria, appear to be related to PWD symptoms. The inoculation of four specific B. xylophilus-associated bacteria isolates in P. pinaster seedlings resulted in the development of some PWD symptoms suggesting that these bacteria likely play an active role with B. xylophilus in PWD. PMID:23091599

  17. Characterization of carbofuran-degrading bacteria isolated from ...

    African Journals Online (AJOL)


    Key words: Pesticides, carbofuran, methomyl, biodegradation, bacteria. INTRODUCTION .... polymerase chain reaction (PCR) amplification and partial sequence analysis of ..... Beutel KK (1986). Chlorinated hydrocarbon, In W. Gerhartz (ed.),.

  18. Investigation of IR absorption spectra of oral cavity bacteria (United States)

    Belikov, Andrei V.; Altshuler, Gregory B.; Moroz, Boris T.; Pavlovskaya, Irina V.


    The results of comparative investigation for IR and visual absorption spectra of oral cavity bacteria are represented by this paper. There are also shown the main differences in absorption spectra of such pure bacteria cultures as : E- coli, Candida, Staph, Epidermidis, and absorption spectra of bacteria colonies cultured in tooth root canals suspected to harbour several endodontical problems. The results of experimental research targeted to investigate an effect of such combined YAG:Nd and YAG:Cr; Tm; Ho laser parameters like: wavelength, energy density, average power and etc., to oral cavity bacteria deactivation are given finally.

  19. Physical mode of bacteria and virus coevolution (United States)

    Han, Pu; Niestemski, Liang; Deem, Michael


    Single-cell hosts such as bacteria or archaea possess an adaptive, heritable immune system that protects them from viral invasion. This system, known as the CRISPR-Cas system, allows the host to recognize and incorporate short foreign DNA or RNA sequences from viruses or plasmids. The sequences form what are called ``spacers'' in the CRISPR. Spacers in the CRISPR loci provide a record of the host and predator coevolution history. We develop a physical model to study the dynamics of this coevolution due to immune pressure. Hosts and viruses reproduce, die, and evolve due to viral infection pressure, host immune pressure, and mutation. We will discuss the differing effects of point mutation and recombination on CRISPR evolution. We will also discuss the effect of different spacer deletion mechanisms. We will describe population structure of hosts and viruses, how spacer diversity depends on position within CRISPR, and match of the CRISPR spacers to the virus population.

  20. Streptomyces bacteria as potential probiotics in aquaculture

    Directory of Open Access Journals (Sweden)

    Tan Loh eTeng Hern


    Full Text Available In response to the increased seafood demand from the ever-going human population, aquaculture has become the fastest growing animal food-producing sector. However, the indiscriminate use of antibiotics as a biological control agents for fish pathogens has led to the emergence of antibiotic resistance bacteria. Probiotics are defined as living microbial supplement that exert beneficial effects on hosts as well as improvement of environmental parameters. Probiotics have been proven to be effective in improving the growth, survival and health status of the aquatic livestock. This review aims to highlight the genus Streptomyces can be a good candidate for probiotics in aquaculture. Studies showed that the feed supplemented with Streptomyces could protect fish and shrimp from pathogens as well as increase the growth of the aquatic organisms. Furthermore, the limitations of Streptomyces as probiotics in aquaculture is also highlighted and solutions are discussed to these limitations.

  1. [Antimicrobial susceptibility testing of anaerobic bacteria]. (United States)

    García-Sánchez, José E; García-Sánchez, Enrique; García-García, María Inmaculada


    The anaerobic bacteria resistance to antibiotics is increasing, and even has appeared against the most active of those, like metronidazol and carbapenems. This fact forces to make and periodical sensibility tests -at least in the most aggressive and virulent species, in cases that they are isolated from life locations and in the absence of therapeutic response- to check the local sensibility and to establish suitable empiric therapies, all based on multicentric studies carried out in order to this or well to check the activity of new antibiotics. For the laboratory routine, the easiest sensibility method is the E-test/MIC evaluator. Another alternative is microdilution, that's only normalized for Bacteroides. There are preliminary facts that allow the use of disc diffusion method in some species of Bacteroides and Clostridium. For the temporal and multicentric studies, the procedure is dilution in agar plate, the reference method. Copyright © 2014 Elsevier España, S.L. All rights reserved.

  2. REGEN: Ancestral Genome Reconstruction for Bacteria

    Directory of Open Access Journals (Sweden)

    João C. Setubal


    Full Text Available Ancestral genome reconstruction can be understood as a phylogenetic study with more details than a traditional phylogenetic tree reconstruction. We present a new computational system called REGEN for ancestral bacterial genome reconstruction at both the gene and replicon levels. REGEN reconstructs gene content, contiguous gene runs, and replicon structure for each ancestral genome. Along each branch of the phylogenetic tree, REGEN infers evolutionary events, including gene creation and deletion and replicon fission and fusion. The reconstruction can be performed by either a maximum parsimony or a maximum likelihood method. Gene content reconstruction is based on the concept of neighboring gene pairs. REGEN was designed to be used with any set of genomes that are sufficiently related, which will usually be the case for bacteria within the same taxonomic order. We evaluated REGEN using simulated genomes and genomes in the Rhizobiales order.

  3. Synthesis of Metal Nanoparticles by Bacteria

    Directory of Open Access Journals (Sweden)

    Fikriye Alev Akçay


    Full Text Available Metal particles reduced to nano size by nanotechnological methods are confronted in many different fields such as biomedical and physicochemical, pharmaceutical, electric-electronic, automotive and food industries. Nanoparticles can be produced using chemical, physical and biological methods, of which chemical processes are in common use. However, physical and chemical methods are not environmentally friendly and economical because they require the use of high temperature, high pressure and toxic chemicals. For this reason, interest in the production of metal nanoparticles by biological methods, also called green technology, an environmentally friendly and sustainable approach, has increased in recent years. With some plant extracts and intracellular and extracellular secretions of microorganisms, some reduction reactions take place and metal nanoparticles are produced. Bacteria have been actively involved in nanotechnology in recent years due to their diversity in nature, their ease of isolation, and ease of nanoparticle synthesis. In this article, production and application of metal nanoparticles by using bacterial methods have been reviewed.

  4. Acetic Acid Bacteria as Symbionts of Insects

    KAUST Repository

    Crotti, Elena; Chouaia, Bessem; Alma, Alberto; Favia, Guido; Bandi, Claudio; Bourtzis, Kostas; Daffonchio, Daniele


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

  5. Laser-induced fluorescence imaging of bacteria (United States)

    Hilton, Peter J.


    This paper outlines a method for optically detecting bacteria on various backgrounds, such as meat, by imaging their laser induced auto-fluorescence response. This method can potentially operate in real-time, which is many times faster than current bacterial detection methods, which require culturing of bacterial samples. This paper describes the imaging technique employed whereby a laser spot is scanned across an object while capturing, filtering, and digitizing the returned light. Preliminary results of the bacterial auto-fluorescence are reported and plans for future research are discussed. The results to date are encouraging with six of the eight bacterial strains investigated exhibiting auto-fluorescence when excited at 488 nm. Discrimination of these bacterial strains against red meat is shown and techniques for reducing background fluorescence discussed.

  6. REGEN: Ancestral Genome Reconstruction for Bacteria. (United States)

    Yang, Kuan; Heath, Lenwood S; Setubal, João C


    Ancestral genome reconstruction can be understood as a phylogenetic study with more details than a traditional phylogenetic tree reconstruction. We present a new computational system called REGEN for ancestral bacterial genome reconstruction at both the gene and replicon levels. REGEN reconstructs gene content, contiguous gene runs, and replicon structure for each ancestral genome. Along each branch of the phylogenetic tree, REGEN infers evolutionary events, including gene creation and deletion and replicon fission and fusion. The reconstruction can be performed by either a maximum parsimony or a maximum likelihood method. Gene content reconstruction is based on the concept of neighboring gene pairs. REGEN was designed to be used with any set of genomes that are sufficiently related, which will usually be the case for bacteria within the same taxonomic order. We evaluated REGEN using simulated genomes and genomes in the Rhizobiales order.

  7. Degradation of multiwall carbon nanotubes by bacteria

    International Nuclear Information System (INIS)

    Zhang, Liwen; Petersen, Elijah J.; Habteselassie, Mussie Y.; Mao, Liang; Huang, Qingguo


    Understanding the environmental transformation of multiwall carbon nanotubes (MWCNTs) is important to their life cycle assessment and potential environmental impacts. We report that a bacterial community is capable of degrading 14 C-labeled MWCNTs into 14 CO 2 in the presence of an external carbon source via co-metabolism. Multiple intermediate products were detected, and genotypic characterization revealed three possible microbial degraders: Burkholderia kururiensis, Delftia acidovorans, and Stenotrophomonas maltophilia. This result suggests that microbe/MWCNTs interaction may impact the long-term fate of MWCNTs. Highlights: •Mineralization of MWCNTs by a bacterial community was observed. •The mineralization required an external carbon source. •Multiple intermediate products were identified in the MWCNT degrading culture. •Three bacterial species were found likely responsible for MWCNT degradation. -- The 14 C-labeled multiwall carbon nanotubes can be degraded to 14 CO 2 and other byproducts by a bacteria community under natural conditions

  8. Acetic Acid Bacteria as Symbionts of Insects

    KAUST Repository

    Crotti, Elena


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

  9. Phosphate Solubilizing Bacteria Adaptive to Vinasse

    Directory of Open Access Journals (Sweden)

    Kahar Muzakhar


    Full Text Available Microorganisms identified as phosphate solubilizing bacteria (PSB adaptive to vinasse were successfully screened from sugarcane soil from an agriculatural estate in Jatiroto. By conducting a screening on Pikovskaya’s agar medium (PAM, we found that five different isolates were detected as PSB (pvk-5a, pvk-5b, pvk-6b, pvk-7a, and pvk-8a. Of the five isolates only three could be grown and were found to be adaptive to vinasse based medium without any nutrients added (pvk-5a, pvk-5b and pvk-7a. The three isolates were characterized as coccus and Gram negative with no endospores detected. We suggest that these three isolates can be used as biofertilizer agent to support organic farming.

  10. Enumeration of petroleum hydrocarbon utilizing bacteria

    International Nuclear Information System (INIS)

    Mukherjee, S.; Barot, M.; Levine, A.D.


    In-situ biological treatment is one among a number of emerging technologies that may be applied to the remediation of contaminated soils and groundwater. In 1985, a surface spill of 1,500 gallons of dielectric transformer oil at the Sandia National Laboratories (HERMES II facility) resulted in contamination of soil up to depths of 160 feet. The extent of contamination and site characteristics favored the application of in-situ bioremediation as a potential remedial technology. The purpose of this research was to enumerate indigenous microbial populations capable of degrading petroleum hydrocarbons. Microbial enumeration and characterization methods suitably adapted for hydrocarbon utilizing bacteria were used as an indicator of the presence of viable microbial consortia in excavated oil samples with hydrocarbon (TPH) concentrations ranging from 300 to 26,850 ppm. Microbial activity was quantified by direct and streak plating soil samples on silica gel media. Effects of toxicity and temperature were studied using batch cultures of hydrocarbon utilizing bacteria (selectively isolated in an enrichment medium), at temperatures of 20 and 35 C. It was concluded from this study that it is possible to isolate native microorganisms from contaminated soils from depths of 60 to 160 feet, and with oil concentration ranging from 300 to 26,850 ppm. About 62% of the microorganisms isolated form the contaminated soil were capable of using contaminant oil as a substrate for growth and metabolism under aerobic conditions. Growth rates were observed to be 50% higher for the highest contaminant concentration at 20 C. Resistance to toxicity to contaminant oil was also observed to be greater at 20 C than at 35 C

  11. Diversity of rumen bacteria in canadian cervids.

    Directory of Open Access Journals (Sweden)

    Robert J Gruninger

    Full Text Available Interest in the bacteria responsible for the breakdown of lignocellulosic feedstuffs within the rumen has increased due to their potential utility in industrial applications. To date, most studies have focused on bacteria from domesticated ruminants. We have expanded the knowledge of the microbial ecology of ruminants by examining the bacterial populations found in the rumen of non-domesticated ruminants found in Canada. Next-generation sequencing of 16S rDNA was employed to characterize the liquid and solid-associated bacterial communities in the rumen of elk (Cervus canadensis, and white tailed deer (Odocoileus virginianus. Despite variability in the microbial populations between animals, principle component and weighted UniFrac analysis indicated that bacterial communities in the rumen of elk and white tail deer are distinct. Populations clustered according to individual host animal and not the association with liquid or solid phase of the rumen contents. In all instances, Bacteroidetes and Firmicutes were the dominant bacterial phyla, although the relative abundance of these differed among ruminant species and between phases of rumen digesta, respectively. In the elk samples Bacteroidetes were more predominant in the liquid phase whereas Firmicutes was the most prevalent phyla in the solid digesta (P = 1×10(-5. There were also statistically significant differences in the abundance of OTUs classified as Fibrobacteres (P = 5×10(-3 and Spirochaetes (P = 3×10(-4 in the solid digesta of the elk samples. We identified a number of OTUs that were classified as phylotypes not previously observed in the rumen environment. Our results suggest that although the bacterial diversity in wild North American ruminants shows overall similarities to domesticated ruminants, we observed a number of OTUs not previously described. Previous studies primarily focusing on domesticated ruminants do not fully represent the microbial diversity of the

  12. Stress Physiology of Lactic Acid Bacteria (United States)

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


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

  13. Effect of air pollution on the total bacteria and pathogenic bacteria in different sizes of particulate matter. (United States)

    Liu, Huan; Zhang, Xu; Zhang, Hao; Yao, Xiangwu; Zhou, Meng; Wang, Jiaqi; He, Zhanfei; Zhang, Huihui; Lou, Liping; Mao, Weihua; Zheng, Ping; Hu, Baolan


    In recent years, air pollution events have occurred frequently in China during the winter. Most studies have focused on the physical and chemical composition of polluted air. Some studies have examined the bacterial bioaerosols both indoors and outdoors. But few studies have focused on the relationship between air pollution and bacteria, especially pathogenic bacteria. Airborne PM samples with different diameters and different air quality index values were collected in Hangzhou, China from December 2014 to January 2015. High-throughput sequencing of 16S rRNA was used to categorize the airborne bacteria. Based on the NCBI database, the "Human Pathogen Database" was established, which is related to human health. Among all the PM samples, the diversity and concentration of total bacteria were lowest in the moderately or heavily polluted air. However, in the PM2.5 and PM10 samples, the relative abundances of pathogenic bacteria were highest in the heavily and moderately polluted air respectively. Considering the PM samples with different particle sizes, the diversities of total bacteria and the proportion of pathogenic bacteria in the PM10 samples were different from those in the PM2.5 and TSP samples. The composition of PM samples with different sizes range may be responsible for the variances. The relative humidity, carbon monoxide and ozone concentrations were the main factors, which affected the diversity of total bacteria and the proportion of pathogenic bacteria. Among the different environmental samples, the compositions of the total bacteria were very similar in all the airborne PM samples, but different from those in the water, surface soil, and ground dust samples. Which may be attributed to that the long-distance transport of the airflow may influence the composition of the airborne bacteria. This study of the pathogenic bacteria in airborne PM samples can provide a reference for environmental and public health researchers. Copyright © 2017 Elsevier Ltd

  14. Cadmium resistance of endophytic bacteria and rizosféricas bacteria isolated from Oriza sativa in Colombia

    Directory of Open Access Journals (Sweden)

    Nataly Ayubb T


    Full Text Available The present study had as objective to evaluate in vitro the resistance of endophytic bacteria and rizospheric bacteria to different concentrations of Cadmium.This bacteria were isolated fron different tissues of commercial rice varieties and from bacteria isolated from the rhizosphere in rice plantations of the Nechí (Antioquía and Achí (Bolivar.  Plant growth promotion was evaluated in vitro by nitrogen fixation, phosphate solubilization and siderophores production of endophytic bacteria. Of each tissue isolated from rice plants was carried out isolation in culture medium for endophytic bacteria, and the soil samples were serially diluted in peptone water. Each sample was determined the population density by counting in CFU / g of tissue and morphotypes were separated by shape, color, size and appearance in culture media. Significant differences were observed for density population of bacteria with respect to tissue, with higher values in root (4x1011 g/root, followed of the stem (3x1010g/etem, leaf (5x109 g/ leaf, flag leaf (3x109 g/ flag leaf and with less density in panicle (4x108 g/panicle. The results of the identification with kit API were confirmed the presence of endophytic bacteria Burkholderia cepaceae and rizospheric bacteria Pseudomona fluorescens With the ability to tolerate different concentrations of Cd, fix nitrogen, solubilize phosphates and produce siderophores.

  15. Pathogenic Assay of Probiotic Bacteria Producing Proteolytic Enzymes as Bioremediation Bacteria Against Vannamei Shrimp Larvae (Litopenaeus vannamei

    Directory of Open Access Journals (Sweden)

    Wilis Ari Setyati


    Full Text Available Application of bacteria in bioremediation of shrimp culture ponds is one of the methods used to clean internal pollutants. This study aimed to evaluate the pathogenicity of extracellular proteolytic enzyme produced by the probiotic bacteria as bioremediation bacteria on vannamei shrimp larvae culture. There were five probiotic bacteria, which were successfully isolated from the sediments served as substrate in mangrove area. The isolated bacteria were coded in number as 13, 19, 30, 33, and 36. Pathogenic bacteria Vibrio harveyi was used as positive control. Pathogenic assay was carried out in two different bacterial concentrations, i.e. 10⁸ and 10⁶ cells.mL-1. The results showed that the lowest survival rate (SR of shrimp larvae in positive control V. harveyi was 53 and 65%. Whereas isolates with the highest SR value (100% were obtained from bacteria coded as 13 and 30. Isolates no. 19, 33 and 36 had SR of more than 90%. Total plate count (TPC data showed that the bacteria increased significantly at the end of the study with an average increase value of 24%. The smallest TPC value was shown by bacterial isolate no. 19, while the largest was obtained from the isolate no. 13. These results suggest that all probiotic bacteria were not pathogenic to the vannamei shrimp larvae.   Keywords: aquaculture, shrimp, bioremediation, pathogenesis, vibrio.

  16. Isolation of Crude Oil from Polluted Waters Using Biosurfactants Pseudomonas Bacteria: Assessment of Bacteria Concentration Effects

    Directory of Open Access Journals (Sweden)

    A. Khalifeh


    Full Text Available Biological decomposition techniques and isolation of environmental pollutions using biosurfactants bacteria are effective methods of environmental protection. Surfactants are amphiphilic compounds that are produced by local microorganisms and are able to reduce the surface and the stresses between surfaces. As a result, they will increase solubility, biological activity, and environmental decomposition of organic compounds. This study analyzes the effects of biosurfactants on crude oil recovery and its isolation using pseudomonas sea bacteria species. Preparation of biosurfactants was done in glass flasks and laboratory conditions. Experiments were carried out to obtain the best concentration of biosurfactants for isolating oil from water and destroying oil-in-water or water-in-oil emulsions in two pH ranges and four saline solutions of different concentrations. The most effective results were gained when a concentration of 0.1% biosurfactants was applied.

  17. Determination of Ammonia Oxidizing Bacteria and Nitrate Oxidizing Bacteria in Wastewater and Bioreactors (United States)

    Francis, Somilez Asya


    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.

  18. Bacteria, some permanent tenants Space Station; Bacteria, unos inquilinos permanentes de la estacion espacial

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, B.


    Vacuum cleaners to operate the vacuum or rags with ethanol they are the products of cleaning of the astronauts. Is there tight spaces fully sterilized? It seems not, even in the Space Station International (ISS). When it comes to bacteria, they are able to travel more than 400 kilometers housed in costumes, bodies and interior of the astronauts themselves and settle in a enclosed space where-unlike in a {sup c}leanroom 'terrestre- the air is not recycled. A NASA study has found an abundance of bacteria 'opportunists' which, although harmless on Earth, they might derivasen cause infections in inflammations or skin irritations. Not forgetting those fungi that could damage or affect the infrastructure equipment space. (Author)

  19. Seed-vectored endophytic bacteria modulate development of rice seedlings. (United States)

    Verma, S K; Kingsley, K; Irizarry, I; Bergen, M; Kharwar, R N; White, J F


    The aim of the present study was to evaluate the effects of the removal of indigenous bacteria from rice seeds on seedling growth and development. Here we report the presence of three indigenous endophytic bacteria in rice seeds that play important roles in modulating seedling development (shoot and root lengths, and formation of root hairs and secondary roots) and defence against pathogens. Seed-associated bacteria were removed using surface sterilization with NaOCl (bleach) followed by antibiotic treatment. When bacteria were absent, growth of seedlings in terms of root hair development and overall seedling size was less than that of seedlings that contained bacteria. Reactive oxygen staining of seedlings showed that endophytic bacteria became intracellular in root parenchyma cells and root hairs. Roots containing endophytic bacteria were seen to stain densely for reactive oxygen, while roots free of bacteria stained lightly for reactive oxygen. Bacteria were isolated and identified as Enterobacter asburiae (VWB1), Pantoea dispersa (VWB2) and Pseudomonas putida (VWB3) by 16S rDNA sequencing. Bacteria were found to produce indole acetic acid (auxins), inhibited the pathogen Fusarium oxysporum and solubilized phosphate. Reinoculation of bacteria onto seedlings derived from surface-disinfected rice and Bermuda grass seeds significantly restored seedling growth and development. Rice seeds harbour indigenous bacterial endophytes that greatly influence seedling growth and development, including root and shoot lengths, root hair formation and disease susceptibility of rice seedlings. This study shows that seeds of rice naturally harbour bacterial endophytes that play key roles in modulation of seedling development. © 2017 The Society for Applied Microbiology.

  20. BioNLP Shared Task--The Bacteria Track. (United States)

    Bossy, Robert; Jourde, Julien; Manine, Alain-Pierre; Veber, Philippe; Alphonse, Erick; van de Guchte, Maarten; Bessières, Philippe; Nédellec, Claire


    We present the BioNLP 2011 Shared Task Bacteria Track, the first Information Extraction challenge entirely dedicated to bacteria. It includes three tasks that cover different levels of biological knowledge. The Bacteria Gene Renaming supporting task is aimed at extracting gene renaming and gene name synonymy in PubMed abstracts. The Bacteria Gene Interaction is a gene/protein interaction extraction task from individual sentences. The interactions have been categorized into ten different sub-types, thus giving a detailed account of genetic regulations at the molecular level. Finally, the Bacteria Biotopes task focuses on the localization and environment of bacteria mentioned in textbook articles. We describe the process of creation for the three corpora, including document acquisition and manual annotation, as well as the metrics used to evaluate the participants' submissions. Three teams submitted to the Bacteria Gene Renaming task; the best team achieved an F-score of 87%. For the Bacteria Gene Interaction task, the only participant's score had reached a global F-score of 77%, although the system efficiency varies significantly from one sub-type to another. Three teams submitted to the Bacteria Biotopes task with very different approaches; the best team achieved an F-score of 45%. However, the detailed study of the participating systems efficiency reveals the strengths and weaknesses of each participating system. The three tasks of the Bacteria Track offer participants a chance to address a wide range of issues in Information Extraction, including entity recognition, semantic typing and coreference resolution. We found common trends in the most efficient systems: the systematic use of syntactic dependencies and machine learning. Nevertheless, the originality of the Bacteria Biotopes task encouraged the use of interesting novel methods and techniques, such as term compositionality, scopes wider than the sentence.

  1. Acetic acid bacteria: A group of bacteria with versatile biotechnological applications. (United States)

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


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

  2. Detection of Sulphate-Reducing Bacteria and Others Cultivable Facultative Bacteria in Dental Tissues

    Directory of Open Access Journals (Sweden)

    Lúcio de Souza Gonçalves


    Full Text Available Aim: To detect for the presence of sulphate-reducing bacteria (SRB and evaluate the possible association between SRB and cultivable facultative bacterial of oral sites with different periodontal conditions. Methods: The study was carried out on 9 samples from different oral sites in 8 patients (two samples were collected from the same patient. Material was collected using modified Postgate E culture medium, indicated for the growth and isolation of SRB. In addition, a reducing solution for anaerobic bacteria was used as a transport solution for facultative bacteria and identified by polymerase chain reaction amplification (PCR and sequencing of the 16S rRNA gene. Results: SRB was found in 3 patient samples: the first in a root fragment, the second in a root fragment and a healthy tooth with vertical bone loss and a mobility degree of 3; and the third in a healthy tooth extracted for orthodontic treatment. In the final patient, the cultivable facultative species Lactobacillus casei was identified. Other facultative bacterial species were identified in patient 5 (Kurthia Gibsonii and patient 7 (Pseudomonas aeruginosa. Conclusions: The detection of SRB in different dental tissues with distinct periodontal features demonstrated that new studies need to be developed in order to determine the true role of SRB in the oral microbiota. In addition, it was possible to verify the presence of Lactobacillus casei together with SRB in one sample.

  3. Mechanistic modeling of biocorrosion caused by biofilms of sulfate reducing bacteria and acid producing bacteria. (United States)

    Xu, Dake; Li, Yingchao; Gu, Tingyue


    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. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Laminar flow assisted anisotropic bacteria absorption for chemotaxis delivery of bacteria-attached microparticle (United States)

    Huh, Keon; Oh, Darong; Son, Seok Young; Yoo, Hyung Jung; Song, Byeonghwa; Cho, Dong-il Dan; Seo, Jong-Mo; Kim, Sung Jae


    The concepts of microrobots has been drawn significant attentions recently since its unprecedented applicability in nanotechnology and biomedical field. Bacteria attached microparticles presented in this work are one of pioneering microrobot technology for self-propulsion or producing kinetic energy from ambient for their motions. Microfluidic device, especially utilizing laminar flow characteristics, were employed for anisotropic attachment of Salmonella typhimurium flagellated chemotactic bacteria to 30 um × 30 um and 50 um × 50 um microparticles that made of biodegradable polymer. Any toxic chemicals or harmful treatments were excluded during the attachment process and it finished within 100 s for the anisotropic attachment. The attachments were directly confirmed by fluorescent intensity changes and SEM visualization. Chemotaxis motions were tracked using aspartate and the maximum velocity of the bacteria-attached microrobot was measured to be 5 um/s which is comparable to prior state of art technologies. This reusable and scalable method could play a key role in chemotaxis delivery of functional microparticles such as drug delivery system.

  5. Bioactive proteins against pathogenic and spoilage bacteria

    Directory of Open Access Journals (Sweden)

    Mahmoud Z. Sitohy


    Full Text Available Background: It is likely that both human nutrition and the nutrition of livestock are benefited by the presence of bioactive proteins within their respective diet regimes. Bioactive proteins have been defined as specific protein fragments that positively impact bodily functions or conditions and may, ultimately, influence overall human health. The ingestion of bioactive proteins may have an effect on the major body systems—namely, the cardiovascular, digestive, immune and nervous systems. According to their functional properties, bioactive proteins may be classified as antimicrobial, antithrombotic, antihypertensive, opioid, immune-modulatory, mineral binding and anti-oxidative. There are many examples of biologically active food proteins and active peptides that can be obtained from various food protein sources. They have a physiological significance beyond the pure nutritional requirements; in other wordsthey have the acquisition of nitrogen for normal growth and maintenance. Objective: This study aims to specify and characterize the extent and mode of action of bioactive proteins in their native form, (glycinin, glycinin basic sub-unit and β-conglycinin against specific main pathogens (Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella enterica serovar Enteritidis. We will be using standard media while identifying the main constituents responsible for this action. Methods: Glycinin, basic sub-unit and β-conglycinin were isolated from soybean protein and tested for their antimicrobial action against pathogenic and spoilage bacteria, They were thencompared to the properties of penicillin. Methylated soybean protein and also methylated chickpea protein (MSP and MCP, with isoelectric points around pI 8, were prepared by esterifying. 83 % of their free carboxyl groups and their interactions with Gram positive and Gram negative bacteria were examined. Results: The three divisions of cationic proteins exhibited antibacterial

  6. Seeing green bacteria in a new light: genomics-enabled studies of the photosynthetic apparatus in green sulfur bacteria and filamentous anoxygenic phototrophic bacteria

    DEFF Research Database (Denmark)

    Frigaard, Niels-Ulrik; Bryant, Donald A


    Based upon their photosynthetic nature and the presence of a unique light-harvesting antenna structure, the chlorosome, the photosynthetic green bacteria are defined as a distinctive group in the Bacteria. However, members of the two taxa that comprise this group, the green sulfur bacteria...... (Chlorobi) and the filamentous anoxygenic phototrophic bacteria ("Chloroflexales"), are otherwise quite different, both physiologically and phylogenetically. This review summarizes how genome sequence information facilitated studies of the biosynthesis and function of the photosynthetic apparatus...... a and carotenoid biosynthesis enzymes, gene cluster analysis in Cfx. aurantiacus, and gene inactivation studies in Chl. tepidum. Based on these results, BChl a and BChl c biosynthesis is similar in the two organisms, whereas carotenoid biosynthesis differs significantly. In agreement with its facultative anaerobic...

  7. Biochanin A improves fiber fermentation by cellulolytic bacteria (United States)

    The objective was to determine the effect of the isoflavone biochanin A (BCA) on rumen cellulolytic bacteria and consequent fermentative activity. When bovine microbial rumen cell suspensions (n = 3) were incubated (24 h, 39 °C) with ground hay, cellulolytic bacteria proliferated, short chain fatty...

  8. Nitrogen acquisition in Agave tequilana from degradation of endophytic bacteria. (United States)

    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


    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.

  9. Fecal bacteria source characterization and sensitivity analysis of SWAT 2005 (United States)

    The Soil and Water Assessment Tool (SWAT) version 2005 includes a microbial sub-model to simulate fecal bacteria transport at the watershed scale. The objectives of this study were to demonstrate methods to characterize fecal coliform bacteria (FCB) source loads and to assess the model sensitivity t...

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

    NARCIS (Netherlands)

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


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

  11. Lactic Acid Bacteria Differentially Activate Natural Killer Cells

    DEFF Research Database (Denmark)

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

    antigen presenting cells and T-cells. Bacteria translocating across the gastrointestinal mucosa are presumed to gain access to NK cell compartments, as consumption of certain strains of lactic acid bacteria has been shown to increase in vivo NK cytotoxic activity. On-going research in our lab aims...

  12. Population dynamics of bacteria introduced into bentonite amended soil

    NARCIS (Netherlands)

    Heijnen, C.


    Bacteria have frequently been introduced into the soil environment, e.g. for increasing crop production or for biological control purposes. Many applications require high numbers of surviving organisms in order to be effective. However, survival of bacteria after introduction into soil is

  13. Antimicrobial resistance in aerobic bacteria isolated from oral ...

    African Journals Online (AJOL)

    ... varied antimicrobial susceptibility patterns. The oral cavities of hunting dogs are laden with multi-drug resistant bacteria of significant public health importance that could be transferred to humans through contaminated hunted games and bite wound. Keywords: Aerobic bacteria, Antimicrobial resistance, Dogs, Oral cavity, ...

  14. Glass bead transformation method for gram-positive bacteria


    Rattanachaikunsopon, Pongsak; Phumkhachorn, Parichat


    A simple, inexpensive and reproducible transformation method was developed for Gram-positive bacteria. It was based on agitation of bacterial protoplasts with glass beads in the presence of DNA and polyethylene glycol. By using this method, introduction of pGK12 into protoplasts of several strains of Gram-positive bacteria was achieved.

  15. Sulphur oxidising bacteria in mangrove ecosystem: A review ...

    African Journals Online (AJOL)

    Sulphur-oxidizing bacteria such as photoautotrophs, chemolithotrophs and heterotrophs play an important role in the mangrove environment for the oxidation of the toxic sulphide produced by sulphur reducing bacteria and act as a key driving force behind all sulphur transformations in the mangrove ecosystem which is ...

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

    NARCIS (Netherlands)

    Brooijmans, R.J.W.; Smit, B.; Santos, dos F.; Riel, van J.; Vos, de W.M.; Hugenholtz, J.


    ABSTRACT: BACKGROUND: For some lactic acid bacteria higher biomass production as a result of aerobic respiration has been reported upon supplementation with heme and menaquinone. In this report, we have studied a large number of species among lactic acid bacteria for the existence of this trait.

  17. The identification of anaerobic bacteria using MALDI-TOF MS

    NARCIS (Netherlands)

    Veloo, A. C. M.; Welling, G. W.; Degener, J. E.

    Matrix Assisted Laser Desorption and Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) has gained more and more popularity for the identification of bacteria. Several studies show that bacterial diagnosticis is being revolutionized by the application of MALDI-TOF MS. For anaerobic bacteria,

  18. Hydrocarbon degradation potentials of bacteria isolated from spent ...

    African Journals Online (AJOL)

    Hydrocarbon degradation potentials of bacteria isolated from spent lubricating oil contaminated soil. ... This study has shown that resident bacteria strains in lubricating oil contaminated soils have potential application in the bioremediation of oil polluted sites and enhance the possibility of developing models and strategies ...

  19. Hydrocarbon-degrading Capability of Bacteria isolated from a Maize ...

    African Journals Online (AJOL)

    Hydrocarbon-degrading Capability of Bacteria isolated from a Maize-Planted, Kerosene-contaminated Ilorin Alfisol. ... also revealed that some bacteria survive and even thrive in kerosene contaminated soil and hence have the potential to be used in biodegradation and/or bioremediation of oil contaminated soils and water.

  20. Rapid separation of bacteria from blood - Chemical aspects. (United States)

    Alizadeh, Mahsa; Wood, Ryan L; Buchanan, Clara M; Bledsoe, Colin G; Wood, Madison E; McClellan, Daniel S; Blanco, Rae; Ravsten, Tanner V; Husseini, Ghaleb A; Hickey, Caroline L; Robison, Richard A; Pitt, William G


    To rapidly diagnose infectious organisms causing blood sepsis, bacteria must be rapidly separated from blood, a very difficult process considering that concentrations of bacteria are many orders of magnitude lower than concentrations of blood cells. We have successfully separated bacteria from red and white blood cells using a sedimentation process in which the separation is driven by differences in density and size. Seven mL of whole human blood spiked with bacteria is placed in a 12-cm hollow disk and spun at 3000rpm for 1min. The red and white cells sediment more than 30-fold faster than bacteria, leaving much of the bacteria in the plasma. When the disk is slowly decelerated, the plasma flows to a collection site and the red and white cells are trapped in the disk. Analysis of the recovered plasma shows that about 36% of the bacteria is recovered in the plasma. The plasma is not perfectly clear of red blood cells, but about 94% have been removed. This paper describes the effects of various chemical aspects of this process, including the influence of anticoagulant chemistry on the separation efficiency and the use of wetting agents and platelet aggregators that may influence the bacterial recovery. In a clinical scenario, the recovered bacteria can be subsequently analyzed to determine their species and resistance to various antibiotics. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. unanswerable questions just as interesting as unculturable bacteria!

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. UNANSWERABLE QUESTIONS JUST AS INTERESTING AS UNCULTURABLE BACTERIA! How can landmark research be done in a college? What is the need to isolate novel bacteria when the ones already isolated are not completely studied? How can one do ...

  2. Bacteria isolated from the airways of paediatric patients with ...

    African Journals Online (AJOL)

    Knowledge of which bacteria are found in the airways of paediatric patients with bronchiectasis unrelated to cystic fibrosis. (CF) is important in defining empirical antibiotic guidelines for the treatment of acute infective exacerbations. Objective. To describe the bacteria isolated from the airways of children with non-CF ...

  3. Effect of inulin and probiotic bacteria on growth, survival, immune ...

    African Journals Online (AJOL)

    The effect of inulin and probiotic bacteria on the growth, survival, immune response and viral prevalence of white spot syndrome virus (WSSV) in white shrimp was evaluated. Presumptive bacilli and lactic acid bacteria (LAB) were characterized for hemolytic and enzymatic activity, hydrophobicity and antagonism against ...

  4. Isolation and characterization of heavy metal tolerant bacteria from ...

    African Journals Online (AJOL)

    Panteka stream is a flowing stream polluted with wastes from the activities of mechanics. Water samples collected at different points of the stream were analysed in order to determine the level of heavy metal contamination and bacteria diversity with the view to elucidating the bioremediating potentials of the bacteria isolates ...

  5. 9th International Symposium on Lactic Acid Bacteria

    NARCIS (Netherlands)

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

    What’s new in the field of lactic acid bacteria? The 9th International Symposium on Lactic Acid Bacteria (LAB9) will take place 31 August to 4 September 2008 in Egmond aan Zee, The Netherlands. Traditionally, the triannual LAB symposium focuses on the themes of genetics, physiology, and applications

  6. Unusual rise in mercury-resistant bacteria in coastal environs

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.; De, J.

    A sharp rise in mercury-resistant bacteria (MRB) capable of tolerating very high concentration of Hg was observed over the last 3-4 years in the coastal environs of India. While none or negligible colony-forming units (CFU) of bacteria were counted...

  7. Screening of endophytic plant growth-promoting bacteria isolated ...

    African Journals Online (AJOL)

    Probiotic bacteria, inhabiting the endosphere of plants, presents a major opportunity to develop cheap and eco-friendly alternatives to synthetic agrochemicals. Using standard microbiological procedures, culturable bacteria were isolated from the endosphere (root, stem and leaf) of two Nigerian rice varieties (Ofada and ITA ...

  8. Stalking Antibiotic-Resistant Bacteria in Common Vegetables (United States)

    Brock, David; Boeke, Caroline; Josowitz, Rebecca; Loya, Katherine


    The study developed a simple experimental protocol for studying antibiotic resistant bacteria that will allow students to determine the proportion of such bacteria found on common fruit and vegetable crops. This protocol can open up the world of environmental science and show how human behavior can dramatically alter ecosystems.

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

    African Journals Online (AJOL)

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

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

    NARCIS (Netherlands)

    Kets, E.P.W.


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

  11. The Shared Antibiotic Resistome of Soil Bacteria and Human Pathogens

    DEFF Research Database (Denmark)

    Forsberg, Kevin J.; Reyes, Alejandro; Wang, Bin


    protocol to assemble short-read sequence data after antibiotic selection experiments, using 12 different drugs in all antibiotic classes, and compared antibiotic resistance gene sequences between soil bacteria and clinically occurring pathogens. Sixteen sequences, representing seven gene products, were...... discovered in farmland soil bacteria within long stretches of perfect nucleotide identity with pathogenic proteobacteria....

  12. Flow cytometric assessment of viability of lactic acid bacteria

    NARCIS (Netherlands)

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


    The viability of lactic acid bacteria is crucial for their applications as dairy starters and as probiotics. We investigated the usefulness of flow cytometry (FCM) for viability assessment of lactic acid bacteria. The esterase substrate carboxyfluorescein diacetate (cFDA) and the dye exclusion DNA

  13. Performance of shcc with bacteria for concrete patch repair

    NARCIS (Netherlands)

    Sierra Beltran, M.G.; Jonkers, H.M.; Schlangen, E.


    The overall performance of concrete patch repair systems depends on the durability of and compatibility between the concrete substrate and the repair material. This paper investigates the performance of a new type of SHCC material with embedded bacteria as a repair material. The bacteria are a

  14. CcpA-dependent carbon catabolite repression in bacteria

    NARCIS (Netherlands)

    Warner, JB; Lolkema, JS; Warner, Jessica B.


    Carbon catabolite repression (CCR) by transcriptional regulators follows different mechanisms in gram-positive and gram-negative bacteria. In gram-positive bacteria, CcpA-dependent CCR is mediated by phosphorylation of the phosphoenolpyruvate:sugar phosphotransferase system intermediate HPr at a

  15. Visualizing aquatic bacteria by light and transmission electron microscopy. (United States)

    Silva, Thiago P; Noyma, Natália P; Duque, Thabata L A; Gamalier, Juliana P; Vidal, Luciana O; Lobão, Lúcia M; Chiarini-Garcia, Hélio; Roland, Fábio; Melo, Rossana C N


    The understanding of the functional role of aquatic bacteria in microbial food webs is largely dependent on methods applied to the direct visualization and enumeration of these organisms. While the ultrastructure of aquatic bacteria is still poorly known, routine observation of aquatic bacteria by light microscopy requires staining with fluorochromes, followed by filtration and direct counting on filter surfaces. Here, we used a new strategy to visualize and enumerate aquatic bacteria by light microscopy. By spinning water samples from varied tropical ecosystems in a cytocentrifuge, we found that bacteria firmly adhere to regular slides, can be stained by fluorochoromes with no background formation and fast enumerated. Significant correlations were found between the cytocentrifugation and filter-based methods. Moreover, preparations through cytocentrifugation were more adequate for bacterial viability evaluation than filter-based preparations. Transmission electron microscopic analyses revealed a morphological diversity of bacteria with different internal and external structures, such as large variation in the cell envelope and capsule thickness, and presence or not of thylakoid membranes. Our results demonstrate that aquatic bacteria represent an ultrastructurally diverse population and open avenues for easy handling/quantification and better visualization of bacteria by light microscopy without the need of filter membranes.

  16. Transmission of nephridial bacteria of the earthworm Eisenia fetida. (United States)

    Davidson, Seana K; Stahl, David A


    The lumbricid earthworms (annelid family Lumbricidae) harbor gram-negative bacteria in their excretory organs, the nephridia. Comparative 16S rRNA gene sequencing of bacteria associated with the nephridia of several earthworm species has shown that each species of worm harbors a distinct bacterial species and that the bacteria from different species form a monophyletic cluster within the genus Acidovorax, suggesting that there is a specific association resulting from radiation from a common bacterial ancestor. Previous microscopy and culture studies revealed the presence of bacteria within the egg capsules and on the surface of embryos but did not demonstrate that the bacteria within the egg capsule were the same bacteria that colonized the nephridia. We present evidence, based on curing experiments, in situ hybridizations with Acidovorax-specific probes, and 16S rRNA gene sequence analysis, that the egg capsules contain high numbers of the bacterial symbiont and that juveniles are colonized during development within the egg capsule. Studies exposing aposymbiotic hatchlings to colonized adults and their bedding material suggested that juvenile earthworms do not readily acquire bacteria from the soil after hatching but must be colonized during development by bacteria deposited in the egg capsule. Whether this is due to the developmental stage of the host or the physiological state of the symbiont remains to be investigated.

  17. Response of resident bacteria in a tropical detergent effluent ...

    African Journals Online (AJOL)

    Bacteria were isolated from a tropical detergent-polluted stream, and their responses to linear alkylbenzene sulfonate (LAS) were investigated. The responses of the resident bacteria were assessed in terms of their ability or failure to grow in the presence of LAS and of their potential to degrade the surfactant. Eighteen ...

  18. Anti-fungal properties of chitinolytic dune soil bacteria

    NARCIS (Netherlands)

    De Boer, W.; Klein Gunnewiek, P.J.A.; Lafeber, P.; Janse, J.H.; Spit, B.E.; Woldendorp, J.W.


    Anti-fungal properties of chitinolytic soil bacteria may enable them to compete successfully for chitin with fungi. Additionally, the production of chitinase may be part of a lytic system that enables the bacteria to use living hyphae rather than chitin as the actual growth substrate, since chitin

  19. Gram-positive bacteria persisting in the food production environment

    DEFF Research Database (Denmark)

    Knøchel, Susanne; Harmsen, Morten; Knudsen, Bettina


    Many gram-positive bacteria are able to form aggregates or biofilms and resist external stress factors and some gram-positive pathogenic bacteria such as Listeria monocytogenes and Bacillus cereus may persist in the food production environment for extended periods. Most research has focussed...

  20. Prevalence and drug resistance in bacteria of the urinary tract ...

    African Journals Online (AJOL)

    Objective: To obtain data on the prevalence of antibiotic resistance in bacteria isolated from patients with suspected urinary tract infection in Bulawayo province, Zimbabwe. Method: Over a period of one year, 257 urine samples were analyzed for bacteria by standard procedures. Antimicrobial susceptibility testing of isolated ...

  1. Use of thermophilic bacteria for bioremediation of petroleum contaminants

    International Nuclear Information System (INIS)

    Al-Maghrabi, I.M.A.; Bin Aqil, A.O.; Chaalal, O.; Islam, M.R.


    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

  2. Removal of crude petroleum hydrocarbons by heterotrophic bacteria ...

    African Journals Online (AJOL)

    Nitrogenous fertilizer (NPK) plant effluents from NAFCON were used in amending plots of land experimentally polluted with crude oil. Counts of heterotrophic bacteria (THBC) and fungi (TF), and of petroleum utilizing bacteria (PUB) and fungi (PUF) were monitored during an 8 weeks period. Counts obtained showed that ...

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

    African Journals Online (AJOL)

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

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

    African Journals Online (AJOL)

    This study is related to the isolation and identification of strains of local thermophilic lactic acid bacteria belonging to the species, Streptococcus thermophilus and Lactobacillus bulgaricus. These bacteria can exist under extreme conditions of the digestive tract (acidity and high concentration of bile salts) and have a high ...

  5. The bacteria profiles of wounds in diabetic patients hospitalized in ...

    African Journals Online (AJOL)

    Diabetic wound infections still remain a health concern such that correct identification of bacteria is essential in monitoring the spread of the infections as well as in the administration of the correct treatment. This study therefore focuses on isolating and identifying bacteria present in diabetic wounds of hospitalized patients in ...

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

    African Journals Online (AJOL)

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

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

    African Journals Online (AJOL)

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

  8. Damage mechanisms of pathogenic bacteria in drinking water ...

    African Journals Online (AJOL)

    This study aimed at elucidating the inactivation mechanisms of pathogenic bacteria in drinking water during chlorine and solar disinfection using a simple plating method. The well-known bacterial model Escherichia coli was used as pathogenic bacteria for the experiments. The damage mechanisms of E. coli were ...

  9. Utilization of Cypermethrin by bacteria isolated from irrigated soils ...

    African Journals Online (AJOL)

    Soil bacteria capable of utilizing Cypermethrin as a source of carbon were isolated using enrichment technique. The bacteria were Psuedomonas aeruginosa, Serratia spp Micrococcus sp, Staphylococci and Streptococcus sp. Growth of P. aeruginosa was determined in the presence of 1:106 and 1:105 Cypermethrin in ...

  10. The Effect of Antioxidants on Antibiotic Sensitivity of Bacteria


    Azade ATTAR; Akif İ. QURBANOV


    Objective: The effect of different concentrations of antioxidants (ascorbic acid, emoxipin, tocopherol acetate and ionol) on antibiotic sensitivity of bacteria was studied. Method: Bacteria belong to different respiration types: Pseudomonas aeruginosa as aerobe and Escherichia coli as facultative anaerobe were used. Antibiotic sensitivity of microorganisms was determined as minimum inhibitory concentration (MIC) by dilution test. Results: Different concentrations of antioxidants increased the...

  11. 'Atypical' bacteria are a common cause of community-acquired ...

    African Journals Online (AJOL)

    Objectives. To assess the proportion of cases of community· acquired pneumonia caused by 'atypical' bacteria, inclUding the recently discovered Chlamydia pneumoniae, and to compare the clinical, radiographic and laboratory features of patients with and without 'atypical' bacteria. Methods. A prospective serological ...

  12. Degradation of riverine dissolved organic matter by seawater bacteria

    NARCIS (Netherlands)

    Rochelle-Newall, E.J.; Pizay, M-D.; Middelburg, J.J.; Boschker, H.T.S.; Gattuso, J.P.


    The functional response of a seawater bacterial community transplanted into freshwater dissolved organic matter (DOM) was investigated together with the response of natural populations of bacteria to size-fractioned natural source water. Seawater bacteria were incubated over a period of 8 d in

  13. Pathogen detection and gut bacteria identification in Apis cerana ...

    African Journals Online (AJOL)


    other lactic acid bacteria, were isolated from larvae and adult workers, but gave conflicting preliminary identities based on their biochemistry-morphology versus sequence analysis of a partial fragment (1.4 kb) of their 16S rRNA. Key words: Apis cerana indica, bee pathogens, gut bacteria, multiplex polymerase chain ...

  14. Antimicrobial properties of probiotic bacteria from various sources

    African Journals Online (AJOL)



    May 15, 2012 ... The lactic acid bacteria (LAB), a component of several fermented foods including ... lactic acid bacteria grown in MRS broth for 20 to 24 h using centrifugation .... vacuum packed chill-stored meat has potential application for ...

  15. Simple and convenient method for culturing anaerobic bacteria.


    Behbehani, M J; Jordan, H V; Santoro, D L


    A simple and convenient method for culturing anaerobic bacteria is described. Cultures can be grown in commercially available flasks normally used for preparation of sterile external solutions. A special disposable rubber flask closure maintains anaerobic conditions in the flask after autoclaving. Growth of a variety of anaerobic oral bacteria was comparable to that obtained after anaerobic incubation of broth cultures in Brewer Anaerobic Jars.

  16. The Bacteria Quality Of The Indigenously Fermented Milk Product ...

    African Journals Online (AJOL)

    Fifty samples of 'nono', a fermented milk product akin to yoghurt, were carefully collected from three markets in Maiduguri municipality, and were examined for the presence of pathogenic bacteria. Twenty-eight percent of the samples were found to be contaminated with aciduric pathogenic bacteria that may cause ...

  17. The bacteriological safety and antimicrobial susceptibility of bacteria ...

    African Journals Online (AJOL)

    In developing countries the major sources of food-borne illnesses are street vended foods. The aim of this study was thus to assess the prevalence and antibiogram of bacteria from white lupin in Bahir Dar Town. METHODS: A total of 40 samples were processed for detection of indicator bacteria and pathogens from ...

  18. Energy sources of yoghurt bacteria and enhancement of their ...

    African Journals Online (AJOL)

    The energy sources of yoghurt bacteria (Streptococcus thermophilus and Lactobacillus bulgaricus) were examined with a focus on probable impact of sucrose on their galactose uptake. Yoghurt bacteria were isolated from samples of yoghurt which were purchased from different outlets and kept under refrigeration ...

  19. [Bacteriophages in the battle against multidrug resistant bacteria

    NARCIS (Netherlands)

    Meer, J.W.M. van der; Vandenbroucke-Grauls, C.


    Bacteriophages are viruses that infect bacteria. They are highly specific for a bacterial species. The so-called 'lytic phages' can lyse bacteria when they infect them; these phages can be used to treat bacterial infections. Despite a century of experience with phage therapy, the evidence for

  20. Mutagenesis of metal compounds in bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Nishioka, H


    The mutagenic activity of 41 metal compounds was examined by applying the Rec-assay method with Bacillus subtilis H17 (rec/sup +/) and M45 (rec/sup -/) strains. Among these compounds, Na/sub 2/HAsO/sub 4/, CdCl/sub 2/, K/sub 2/CrO/sub 4/, K/sub 2/Cr/sub 2/O/sub 7/, CH/sub 3/HgCl, C/sub 2/H/sub 5/HgCl, CH/sub 3/COOHgC/sub 6/H/sub 5/, MnCl/sub 2/, MnNO/sub 3/, MnSO/sub 4/, Mn(CH/sub 3/COO)/sub 2/, (NH/sub 4/)/sub 2/MoO/sub 4/ and KMoO/sub 4/ showed positive results. The reactions of K/sub 2/Cr/sub 2/O/sub 7/ and (NH/sub 4/)/sub 2/MoO/sub 4/ were especially strong in the assay. Therefore, mutation induction to reversion (try/sup +/) and streptomycin resistance (SM/sup r/) of E. coli B/r WP2 try/sup -/ (hcl/sup +/ and hcr/sup -/) by the two compounds were examined by the following two experimental procedures. Stationary phase bacteria were exposed to the compounds at high concentrations (6.9 x 10/sup -3/ approx. 3.44 x 10/sup -2/M) in M9 buffer for 15 min at 37/sup -/ with shaking. After incubation at 37/sup 0/ for 48 h visible colonies on the plates were scored. Bacteria in M9 buffer were plated in media supplemented with low concentrations (1.7 x 10/sup -5/ approx. 3.4 x 10/sup -5/M) of the compounds. K/sub 2/Cr/sub 2/O/sub 7/ and (NH/sub 4/)/sub 2/MoO/sub 4/ increased the mutation rate of SM/sup r/ and try/sup +/ in both strains treated with either procedure. No marked differences in mutation rate were found between hcr/sup +/ and hcr/sup -/. After treatment with high concentrations of compounds one can imagine that a peroxidation state produced by these peroxides in the media might affect the killing and mutation induction. These results suggest the possibility that the mutagenesis of the metals relate to their atomic values, rather than the peroxidation state as far as these two compounds are concerned.

  1. Sensitivity of certain bacteria to antibiotics and irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Harsojo,; Andini, L S; Siagian, E G; Lina, M R; Zuleiha, S [National Atomic Energy Agency, Jakarta (Indonesia). Pasar Djumat Research Centre


    An experiment has been conducted to find vegetative forms of certain bacteria in Indonesia which are resistant to irradiation, the resistance of which will be compared to that of known radioresistant bacteria micrococcus radiodurans. To inactivate the vegetative forms of resistant bacteria to irradiation high doses are needed, while for storage purposes lower doses change the physical and chemical properties of the stored commodity are preferred. For this purpose the bacteria were irradiated in aerobic condition with gamma radiation doses of 0.1, 0.2 and 0.3 kGy, or treated with antibiotics e.g. tetracycline HCl or chloramphenicol with concentrations of 0.1, 0.2 and 0.3 respectively. The results indicated that doses of 0.2 kGy and 0.1 reduced the ability of the bacteria for multiplication.

  2. Presence of Pathogenic Bacteria and Viruses in the Daycare Environment. (United States)

    Ibfelt, Tobias; Engelund, Eva Hoy; Permin, Anders; Madsen, Jonas Stenløkke; Schultz, Anna Charlotte; Andersen, Leif Percival


    The number of children in daycare centers (DCCs) is rising. This increases exposure to microorganisms and infectious diseases. Little is known about which bacteria and viruses are present in the DCC environment and where they are located. In the study described in this article, the authors set out to determine the prevalence of pathogenic bacteria and viruses and to find the most contaminated fomites in DCCs. Fifteen locations in each DCC were sampled for bacteria, respiratory viruses, and gastrointestinal viruses. The locations were in the toilet, kitchen, and playroom areas and included nursery pillows, toys, and tables, among other things. Coliform bacteria were primarily found in the toilet and kitchen areas whereas nasopharyngeal bacteria were found mostly on toys and fabric surfaces in the playroom. Respiratory viruses were omnipresent in the DCC environment, especially on the toys.

  3. Uptake of americium-241 by algae and bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Geisy, J P; Paine, D


    Algae and bacteria are important factors in the transport and mobilization of elements in the biosphere. These factors may be involved in trophic biomagnification, resulting in a potential human hazard or environmental degradation. Although americium, one of the most toxic elements known, is not required for plant growth, it may be concentrated by algae and bacteria. Therefore, the availability of americium-241 to algae and bacteria was studied to determine their role in the ultimate fate of this element released into the environment. Both algae and bacteria concentrated americium-241 to a high degree, making them important parts of the biomagnification process. The ability to concentrate americium-241 makes algae and bacteria potentially significant factors in cycling this element in the water column. (4 graphs, numerous references, 3 tables)

  4. High resistance of some oligotrophic bacteria to ionizing radiation

    International Nuclear Information System (INIS)

    Nikitin, D.I.; Tashtemirova, M.A.; Pitryuk, I.A.; Sorokin, V.V.; Oranskaya, M.S.; Nikitin, L.E.


    The resistance of seven cultures of eutrophic and oligotrophic bacteria to gamma radiation (at doses up to 360 Gy) was investigated. The bacteria under study were divided into three groups according to their survival ability after irradiation. Methylobacterium organophilum and open-quotes Pedodermatophilus halotoleransclose quotes (LD 50 = 270 Gy) were highly tolerant. By their tolerance, these organisms approached Deinococcus radiodurans. Aquatic ring-shaped (toroidal) bacteria Flectobacillus major and open-quotes Arcocella aquaticaclose quotes (LD 5 = 173 and 210 Gy, respectively) were moderately tolerant. Eutrophic Pseudomonas fluorescens and Escherichia coli (LD 50 = 43 and 38 Gy, respectively) were the most sensitive. X-ray microanalysis showed that in tolerant bacteria the intracellular content of potassium increased and the content of calcium decreased after irradiation. No changes in the element composition of the eutrophic bacterium E. coli were detected. Possible mechanisms of the resistance of oligotrophic bacteria to gamma radiation are discussed

  5. Physiological and genetics studies of highly radiation-resistant bacteria

    International Nuclear Information System (INIS)

    Keller, L.C.


    The phenomenon of radiation resistance was studied using micrococci and Moraxella-Acinetobacter capable of surviving very high doses of gamma radiation which were isolated from foods. Physiological age, or growth phase, was found to be an important factor in making comparisons of radiation-resistance among different bacteria and their mutants. Radiation-resistant bacteria were highly resistant to the lethal effect of nitrosoguanidine used for mutagenesis. Studies of relative resistance of radiation-resistant bacteria, radiation-sensitive mutants, and nonradiation-resistant bacteria to killing by different chemical mutagens did not reveal a correlation between the traits of radiation resistance and mutagen resistance among different strains. Comparisons of plasmid profiles of radiation-resistant bacteria and selected radiation-sensitive mutants suggested the possibility that plasmids may carry genes involved in radiation resistance

  6. Natural soil reservoirs for human pathogenic and fecal indicator bacteria (United States)

    Boschiroli, Maria L; Falkinham, Joseph; Favre-Bonte, Sabine; Nazaret, Sylvie; Piveteau, Pascal; Sadowsky, Michael J.; Byappanahalli, Muruleedhara; Delaquis, Pascal; Hartmann, Alain


    Soils receive inputs of human pathogenic and indicator bacteria through land application of animal manures or sewage sludge, and inputs by wildlife. Soil is an extremely heterogeneous substrate and contains meso- and macrofauna that may be reservoirs for bacteria of human health concern. The ability to detect and quantify bacteria of human health concern is important in risk assessments and in evaluating the efficacy of agricultural soil management practices that are protective of crop quality and protective of adjacent water resources. The present chapter describes the distribution of selected Gram-positive and Gram-negative bacteria in soils. Methods for detecting and quantifying soilborne bacteria including extraction, enrichment using immunomagnetic capture, culturing, molecular detection and deep sequencing of metagenomic DNA to detect pathogens are overviewed. Methods for strain phenotypic and genotypic characterization are presented, as well as how comparison with clinical isolates can inform the potential for human health risk.

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

    International Nuclear Information System (INIS)

    Sanders, S.W.; Maxcy, R.B.


    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 25 0 C 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

  8. Roseobacter-clade bacteria as probiotics in marine larvaeculture

    DEFF Research Database (Denmark)

    Grotkjær, Torben

    Disease caused by fish pathogenic bacteria can cause large scale crashes in marine fish larval rearing units. One of the biggest challenges for aquaculture is the management of these bacterial outbreaks. Vaccines can be admitted to fish but only the juvenile and the adult fish because they need...... to have a mature immune system. This means that the larvae of the fish, until they are 2-3 weeks old are more prone to bacterial infections. A short term solution is antibiotics but this leaves way for the selection for antibiotic resistance among the pathogenic bacteria, which again can be transferred...... to human pathogens. Alternatives are therefore needed and one could be the use of probiotic bacteria. Marine bacteria from the Roseobacter clade (Phaeobacter inhibens) have shown great potential as probiotic bacteria, and we have hypothesized that they could be used to antagonize pathogenic fish...

  9. 3D printing of bacteria into functional complex materials. (United States)

    Schaffner, Manuel; Rühs, Patrick A; Coulter, Fergal; Kilcher, Samuel; Studart, André R


    Despite recent advances to control the spatial composition and dynamic functionalities of bacteria embedded in materials, bacterial localization into complex three-dimensional (3D) geometries remains a major challenge. We demonstrate a 3D printing approach to create bacteria-derived functional materials by combining the natural diverse metabolism of bacteria with the shape design freedom of additive manufacturing. To achieve this, we embedded bacteria in a biocompatible and functionalized 3D printing ink and printed two types of "living materials" capable of degrading pollutants and of producing medically relevant bacterial cellulose. With this versatile bacteria-printing platform, complex materials displaying spatially specific compositions, geometry, and properties not accessed by standard technologies can be assembled from bottom up for new biotechnological and biomedical applications.

  10. Influence of disturbances on bacteria level in an operating room

    DEFF Research Database (Denmark)

    Brohus, Henrik; Hyldig, Mikkel; Kamper, Simon


    In operating rooms great effort is manifested to reduce the bacteria level in order to decrease the risk of infections. The main source of bacteria is the staff and the patient, thus, the resulting bacteria concentration is roughly speaking a combination of the ventilation system and the emission...... from the occupants. This study investigates the influence of two main disturbances in an operating room namely the door opening during the operation and the activity level of the staff. It is found that the frequent door opening in this case does not cause significant transport of air from outside...... the operating room to the wound area of the patient. However, a significant influence of the activity level on the bacteria emission and concentration is found. Counting the number of persons in an operating room to estimate the bacteria source strength is not sufficient, the corresponding activity level must...

  11. A porous silicon optical microcavity for sensitive bacteria detection

    International Nuclear Information System (INIS)

    Li Sha; Huang Jianfeng; Cai Lintao


    A porous silicon microcavity (PSM) is highly sensitive to subtle interface changes due to its high surface area, capillary condensation ability and a narrow resonance peak (∼10 nm). Based on the well-defined optical properties of a PSM, we successfully fabricated a bacteria detection chip for molecular or subcellular analysis by surface modification using undecylenic acid (UA), and the specific recognition binding of vancomycin to the D-alanyl-D-alanine of bacteria. The red shift of the PSM resonance peak showed a good linear relationship with bacteria concentration ranging from 100 to 1000 bacteria ml -1 at the level of relative standard deviation of 0.994 and detection limit of 20 bacteria ml -1 . The resulting PSM sensors demonstrated high sensitivity, good reproducibility, fast response and low cost for biosensing.

  12. A porous silicon optical microcavity for sensitive bacteria detection (United States)

    Li, Sha; Huang, Jianfeng; Cai, Lintao


    A porous silicon microcavity (PSM) is highly sensitive to subtle interface changes due to its high surface area, capillary condensation ability and a narrow resonance peak (~10 nm). Based on the well-defined optical properties of a PSM, we successfully fabricated a bacteria detection chip for molecular or subcellular analysis by surface modification using undecylenic acid (UA), and the specific recognition binding of vancomycin to the D-alanyl-D-alanine of bacteria. The red shift of the PSM resonance peak showed a good linear relationship with bacteria concentration ranging from 100 to 1000 bacteria ml - 1 at the level of relative standard deviation of 0.994 and detection limit of 20 bacteria ml - 1. The resulting PSM sensors demonstrated high sensitivity, good reproducibility, fast response and low cost for biosensing.

  13. A porous silicon optical microcavity for sensitive bacteria detection

    Energy Technology Data Exchange (ETDEWEB)

    Li Sha; Huang Jianfeng; Cai Lintao, E-mail: [CAS Key Lab of Health Informatics, Shenzhen Key Laboratory of Cancer Nanotechnology, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055 (China)


    A porous silicon microcavity (PSM) is highly sensitive to subtle interface changes due to its high surface area, capillary condensation ability and a narrow resonance peak ({approx}10 nm). Based on the well-defined optical properties of a PSM, we successfully fabricated a bacteria detection chip for molecular or subcellular analysis by surface modification using undecylenic acid (UA), and the specific recognition binding of vancomycin to the D-alanyl-D-alanine of bacteria. The red shift of the PSM resonance peak showed a good linear relationship with bacteria concentration ranging from 100 to 1000 bacteria ml{sup -1} at the level of relative standard deviation of 0.994 and detection limit of 20 bacteria ml{sup -1}. The resulting PSM sensors demonstrated high sensitivity, good reproducibility, fast response and low cost for biosensing.

  14. High motility reduces grazing mortality of planktonic bacteria

    DEFF Research Database (Denmark)

    Matz, Carsten; Jurgens, K.


    We tested the impact of bacterial swimming speed on the survival of planktonic bacteria in the presence of protozoan grazers. Grazing experiments with three common bacterivorous nanoflagellates revealed low clearance rates for highly motile bacteria. High-resolution video microscopy demonstrated...... size revealed highest grazing losses for moderately motile bacteria with a cell size between 0.2 and 0.4 mum(3). Grazing mortality was lowest for cells of >0.5 mum(3) and small, highly motile bacteria. Survival efficiencies of >95% for the ultramicrobacterial isolate CP-1 (less than or equal to0.1 mum......(3), >50 mum s(-1)) illustrated the combined protective action of small cell size and high motility. Our findings suggest that motility has an important adaptive function in the survival of planktonic bacteria during protozoan grazing....

  15. Thermophilic Sulfate-Reducing Bacteria in Cold Marine Sediment

    DEFF Research Database (Denmark)



    sulfate-reducing bacteria was detected. Time course experiments showed constant sulfate reduction rates at 4 degrees C and 30 degrees C, whereas the activity at 60 degrees C increased exponentially after a lag period of one day. Thermophilic, endospore-forming sulfate-reducing bacteria, designated strain...... C to search for presence of psychrophilic, mesophilic and thermophilic sulfate-reducing bacteria. Detectable activity was initially only in the mesophilic range, but after a lag phase sulfate reduction by thermophilic sulfate-reducing bacteria were observed. No distinct activity of psychrophilic...... P60, were isolated and characterized as Desulfotomaculum kuznetsovii. The temperature response of growth and respiration of strain P60 agreed well with the measured sulfate reduction at 50 degrees-70 degrees C. Bacteria similar to strain P60 could thus be responsible for the measured thermophilic...

  16. Conspicuous veils formed by vibrioid bacteria on sulfidic marine sediment

    DEFF Research Database (Denmark)

    Thar, Roland Matthias; Kühl, Michael


    , but the bacteria have so far not been isolated in pure culture, and a detailed characterization of their metabolism is still lacking. The bacteria are colorless, gram-negative, and vibrioid-shaped (1.3- to 2.5- by 4- to 10-µm) cells that multiply by binary division and contain several spherical inclusions of poly......We describe the morphology and behavior of a hitherto unknown bacterial species that forms conspicuous veils (typical dimensions, 30 by 30 mm) on sulfidic marine sediment. The new bacteria were enriched on complex sulfidic medium within a benthic gradient chamber in oxygen-sulfide countergradients......, forming a cohesive whitish veil at the oxic-anoxic interface. Bacteria attached to the veil kept rotating and adapted their stalk lengths dynamically to changing oxygen concentrations. The joint action of rotating bacteria on the veil induced a homogeneous water flow from the oxic water region toward...

  17. AZF Microdeletions in Human Semen Infected with Bacteria

    Directory of Open Access Journals (Sweden)

    Hayfa H Hassani


    Full Text Available Bacterial infections are associated with infertility in men. This study was aimed to investigate microdeletions on Yq chromosome in semen infected with bacteria by using bacteriological, biochemical, and serological assays. The investigation showed that 107 of 300 (84.80% semen samples collected from infertile men with primary or secondary infertility were infected with different species of bacteria. Chlamydia trachomatis and Neisseria gonorrheae were the most frequently diagnosed bacteria in the infected semen samples. The percentages of infections of semen samples with C. trachomatis and N. gonorrhea were 42.31% and 35.28% respectively. Genomic DNA from each semen sample infected with predominant bacteria was analyzed for AZF deletions by using multiplex PCR. Different patterns of AZF microdeletions were obtained. It can be concluded that sexually transmitted bacteria may contribute in microdeletions of Yq chromosome by indirectly producing reactive oxygen species and causing gene defect in AZF regions.

  18. Thermophilic, lignocellulolytic bacteria for ethanol production: current state and perspectives

    DEFF Research Database (Denmark)

    Chang, Tinghong; Yao, Shuo


    of cellulolytic and saccharolytic thermophilic bacteria for lignocellulosic ethanol production because of their unique properties. First of all, thermophilic bacteria possess unique cellulolytic and hemicellulolytic systems and are considered as potential sources of highly active and thermostable enzymes...... for efficient biomass hydrolysis. Secondly, thermophilic bacteria ferment a broad range of carbohydrates into ethanol, and some of them display potential for ethanologenic fermentation at high yield. Thirdly, the establishment of the genetic tools for thermophilic bacteria has allowed metabolic engineering......, in particular with emphasis on improving ethanol yield, and this facilitates their employment for ethanol production. Finally, different processes for second-generation ethanol production based on thermophilic bacteria have been proposed with the aim to achieve cost-competitive processes. However, thermophilic...

  19. Thermophilic Sulfate-Reducing Bacteria in Cold Marine Sediment

    DEFF Research Database (Denmark)



    C to search for presence of psychrophilic, mesophilic and thermophilic sulfate-reducing bacteria. Detectable activity was initially only in the mesophilic range, but after a lag phase sulfate reduction by thermophilic sulfate-reducing bacteria were observed. No distinct activity of psychrophilic...... sulfate-reducing bacteria was detected. Time course experiments showed constant sulfate reduction rates at 4 degrees C and 30 degrees C, whereas the activity at 60 degrees C increased exponentially after a lag period of one day. Thermophilic, endospore-forming sulfate-reducing bacteria, designated strain...... P60, were isolated and characterized as Desulfotomaculum kuznetsovii. The temperature response of growth and respiration of strain P60 agreed well with the measured sulfate reduction at 50 degrees-70 degrees C. Bacteria similar to strain P60 could thus be responsible for the measured thermophilic...

  20. Shellfish as reservoirs of bacterial pathogens

    Directory of Open Access Journals (Sweden)

    Harry Hariharan


    Full Text Available The objective of this article is to present an overview on bacterial pathogens associated with shellfish in Grenada and other countries including the authors’ experience. Although there have been considerable published work on vibrios, there is a lack of information on Salmonella serovars associated with various shellfish. In Grenada, for instance the blue land crabs collected from their habitats were found to harbor several Salmonella serovars. Also, it is notable that only minimal research has been done on shellfish such as conchs and whelks, which are common in the Caribbean and West Indies. Information on anaerobic bacteria, particularly, non-spore forming bacteria associated with shellfish, in general, is also scanty. This review re-examines this globally important topic based on the recent findings as well as past observations. Strategies for reduction of bacteria in oysters are briefly mentioned because of the fact that oysters are consumed commonly without complete cooking.