Publications

finding my enemy's enemies.		2004	15289822
diversity and evolution of bdellovibrio-and-like organisms (balos), reclassification of bacteriovorax starrii as peredibacter starrii gen. nov., comb. nov., and description of the bacteriovorax-peredibacter clade as bacteriovoracaceae fam. nov.	a phylogenetic analysis of bdellovibrio-and-like organisms (balos) was performed. it was based on the characterization of 71 strains and on all consequent 16s rrna gene sequences available in databases, including clones identified by data-mining, totalling 120 strains from very varied biotopes. amplified rdna restriction analysis (ardra) accurately reflected the diversity and phylogenetic affiliation of balos, thereby providing an efficient screening tool. extensive phylogenetic analysis of the ...	2004	15388693
genome update: at content in sequenced prokaryotic genomes.		2004	15073284
[a comparative study of the effect of certain pollutants on free-living and immobilized bdellovibrio].	the paper deals with a comparative study of the growth of free-living and immobilized predatory bacteria of the genus bdellovibrio in the presence of toxic concentrations of urea and phenol. it was found that the cell wall of bdelloplasts plays a protective role in the adaptation of bdellovibrios to xenobiotics. the attachment of bdellovibrios to solid surfaces allows them to survive under unfavorable environmental conditions.	2004	15074041
bdellovibrio bacteriovorus strains produce a novel major outer membrane protein during predacious growth in the periplasm of prey bacteria.	bdellovibrio bacteriovorus is a predatory bacterium that is capable of invading a number of gram-negative bacteria. the life cycle of this predator can be divided into a nonreproductive phase outside the prey bacteria and a multiplication phase in their periplasm. it was suggested that during the reproduction phase, b. bacteriovorus reutilizes unmodified components of the prey's cell wall. we therefore examined the outer membranes of b. bacteriovorus strains hd100 (dsm 50701) and hd114 (dsm 5070 ...	2004	15090518
bdellovibrio as therapeutic agents: a predatory renaissance?		2004	15263901
plastic phenotypic resistance to predation by bdellovibrio and like organisms in bacterial prey.	predation at the lowest trophic level, i.e. between bacteria, is poorly understood, hindering efforts to assess its impact on the structure of bacterial communities. the interaction of bdellovibrio and bacteriovorax (bdellovibrio and like organisms, blos), a group of obligate, ubiquitous predatory bacteria, with their gram-negative bacterial prey results in the multiplication of the predator and in the lysis, but not in the eradication, of the prey. we show that the residual, surviving populatio ...	2004	14686937
a predator unmasked: life cycle of bdellovibrio bacteriovorus from a genomic perspective.	predatory bacteria remain molecularly enigmatic, despite their presence in many microbial communities. here we report the complete genome of bdellovibrio bacteriovorus hd100, a predatory gram-negative bacterium that invades and consumes other gram-negative bacteria. its surprisingly large genome shows no evidence of recent gene transfer from its prey. a plethora of paralogous gene families coding for enzymes, such as hydrolases and transporters, are used throughout the life cycle of b. bacteriov ...	2004	14752164
isolation, molecular characterisation and genome sequence of a bacteriophage (chp3) from chlamydophila pecorum.	chlamydiae are obligate intracellular pathogens that have a unique developmental cycle. thirty nine viable isolates representing all nine currently recognised chlamydial species were screened by immunofluorescence with a cross-reacting chlamydiaphage monoclonal antibody. a novel chlamydiaphage (chp3) was detected in c. pecorum, a chlamydial species not previously known to carry bacteriophages. chp3 belongs to the microviridae, members of this virus family are characterised by circular, single-st ...	2004	14976421
downregulation of the mota gene delays the escape of the obligate predator bdellovibrio bacteriovorus 109j from bdelloplasts of bacterial prey cells.	bdellovibrio bacteriovorus is a gram-negative bacterium that preys on other gram-negative bacteria. the lifecycle of b. bacteriovorus alternates between an extracellular flagellated and highly motile non-replicative attack-phase cell and a periplasmic non-flagellated growth-phase cell. the prey bacterium containing periplasmic bdellovibrios becomes spherical but osmotically stable, forming a structure known as the bdelloplast. after completing the growth phase, newly formed bdellovibrios regain ...	2004	14993314
researchers eye "predatory" bacterium for novel antimicrobial strategies.		2004	15010430
predation pattern and phylogenetic analysis of bdellovibrionaceae from the great salt lake, utah.	the bdellovibrionaceae are predatory, intraperiplasmic bacteria that prey upon a variety of gram-negative bacteria. the prey susceptibility pattern is frequently used to characterize new isolates. the objective in this study was to isolate and characterize predators from the great salt lake (gsl) by prey susceptibility testing. to recover the predators, water samples were inoculated into an enrichment medium with vibrio parahaemolyticus as prey. after several days of incubation, the predators we ...	2004	15057478
a symbiont of the tick ixodes ricinus invades and consumes mitochondria in a mode similar to that of the parasitic bacterium bdellovibrio bacteriovorus.	we have recently performed molecular characterisation of an intracellular alpha-proteobacterium, named irices1, which resides in the ovarian tissue of female ixodes ricinus ticks from italy. a unique characteristic of this bacterium is its ability to invade the mitochondria of the cells in which it resides. although some ultrastructural studies have been performed on close relatives of this bacterium from i. ricinus in england and switzerland, a number of questions remain about its movement with ...	2004	14729452
[ultrastructural basis of interactions between prokaryotes and eukaryotes in different symbiotic models].	this paper reviews the author's contribution to the knowledge of the ultrastructural basis of the prokaryote-eukaryote interactions in different models assessed by an ultrastructural approach. in agreement with the hypothesis of the origin of eukaryotic cells, which are chimeras of several prokaryotes with different morpho-functional specializations, symbiosis had major consequence for evolution of life. in arthropods, one of the most successful lifestyles, the presence of endosymbiotic prokaryo ...	2004	15305681
a novel assay to monitor predator-prey interactions for bdellovibrio bacteriovorus 109 j reveals a role for methyl-accepting chemotaxis proteins in predation.	bdellovibrio bacteriovorus are gram-negative bacteria that prey upon other gram-negative bacteria, including some pathogens, in a wide variety of habitats including soil, sewage, marine and estuarine environments. in order to facilitate studies on predation by this organism, we have developed a method that assays killing of luminescent escherichia coli by b. bacteriovorus. moreover, we have used this assay to compare predation of cells by derivatives of b. bacteriovorus containing targeted mutat ...	2003	12558595
the obligate predatory bdellovibrio bacteriovorus possesses a neutral lipid a containing alpha-d-mannoses that replace phosphate residues: similarities and differences between the lipid as and the lipopolysaccharides of the wild type strain b. bacteriovorus hd100 and its host-independent derivative hi100.	bdellovibrio bacteriovorus are predatory bacteria that penetrate gram-negative bacteria and grow intraperiplasmically at the expense of the prey. it was suggested that b. bacteriovorus partially degrade and reutilize lipopolysaccharide (lps) of the host, thus synthesizing an outer membrane containing structural elements of the prey. according to this hypothesis a host-independent mutant should possess a chemically different lps. therefore, the lipopolysaccharides of b. bacteriovorus hd100 and it ...	2003	12743115
jerusalem artichokes stimulate growth of broiler chickens and protect them against endotoxins and potential cecal pathogens.	control of intestinal pathogens during the earliest phases of broiler production may be the best strategy for the reduction of human pathogens on processed broiler carcasses. the recent ban on antibiotics in poultry feed has served to focus much attention on alternative methods of controlling the gastrointestinal microflora. a field trial was conducted to evaluate the effect of the fructan-rich jerusalem artichoke, or topinambur (administered as 0.5% topinambur syrup in drinking water), on cultu ...	2003	14627303
investigations into the life cycle of the bacterial predator bdellovibrio bacteriovorus 109j at an interface by atomic force microscopy.	atomic force microscopy was used to image bdellovibrio bacteriovorus 109j, a gram-negative bacterial predator that consumes a variety of other gram-negative bacteria. in predator-prey communities grown on filters at hydrated air-solid interfaces, repeated cycles of hunting, invasion, growth, and lysis occurred readily even though the cells were limited to near two-dimensional movement. this system allowed us to image the bacteria directly without extensive preparation or modification, and many o ...	2003	12719266
predatory prokaryotes: an emerging research opportunity.	predatory prokaryotes have evolved a unique strategy of obtaining energy and biosynthetic materials from their surroundings: acquiring them from other living bacterial cells. these types of microbes have been found in a diverse variety of environments, and may play an important role in modulating microbial population structure and dynamics, as has been hypothesized for marine viruses and possibly protists. only one genus of predatory bacterium, bdellovibrio, has been extensively described and st ...	2002	12432957
16s rdna sequence analysis of environmental bdellovibrio-and-like organisms (balo) reveals extensive diversity.	bdellovibrio-and-like organisms (balo) are gram-negative, predatory bacteria that inhabit terrestrial, freshwater and salt-water environments. historically, these organisms have been classified together despite documented genetic differences between isolates. the genetic diversity of these microbes was assessed by sequencing the 16s rrna gene. primers that selectively amplify predator 16s rdna, and not contaminating prey dna, were utilized to study 17 freshwater and terrestrial and nine salt-wat ...	2002	12508873
microviridae, a family divided: isolation, characterization, and genome sequence of phimh2k, a bacteriophage of the obligate intracellular parasitic bacterium bdellovibrio bacteriovorus.	a novel single-stranded dna phage, phimh2k, of bdellovibrio bacteriovorus was isolated, characterized, and sequenced. this phage is a member of the microviridae, a family typified by bacteriophage phix174. although b. bacteriovorus and escherichia coli are both classified as proteobacteria, phimh2k is only distantly related to phix174. instead, phimh2k exhibits an extremely close relationship to the microviridae of chlamydia in both genome organization and encoded proteins. unlike the double-str ...	2002	11807069
predation in the presence of decoys: an inhibitory factor on pathogen control by bacteriophages or bdellovibrios in dense and diverse ecosystems.	several attempts have been made at the removal of specific pathogens from the intestinal microflora using either bacteriophages or "predatory" bacteria such as bdellovibrio spp. to date these attempts have had mixed success. a mechanism explaining these findings based on competitive hindrance by non-prey, or decoy species is put forward. it is shown that this hindrance tends to damp out predator-prey oscillations, and therefore reduces the probability of prey extinction. possible experiments to ...	2001	11162050
a novel sphingophosphonolipid head group 1-hydroxy-2-aminoethyl phosphonate in bdellovibrio stolpii.	members of the bacterial genus bdellovibrio include strains that are free-living, whereas others are known to invade and parasitize larger gram-negative bacteria. the bacterium can synthesize several sphingophospholipid compounds including those with phosphoryl bonds as well as phosphonyl bonds. in the present study, the dominant sphingophosphonolipid component was isolated by column chromatography, and the long-chain bases, fatty acids, and polar head groups were identified by thin-layer and ga ...	2001	11432465
analysis of phenotypic diversity among host-independent mutants of bdellovibrio bacteriovorus 109j.	host-independent (h-i) mutants of the obligate bacterial parasite bdellovibrio bacteriovorus were isolated from wild-type strain 109j. seven h-i mutants differed in morphological features such as cell length (2-30 microm) and shape (short or long spirals or rod-like), plaque size, and pigmentation (from almost colorless to bright orange). the mutants exhibited widely different growth capabilities in rich medium, with biomass doubling times and final biomass varying by a factor of two or more. gr ...	2001	11511869
taxonomic studies of predatory bdellovibrios based on 16s rrna analysis, ribotyping and the hit locus and characterization of isolates from the gut of animals.	the aim of our study was to obtain data for the molecular characterization of bdellovibrio bacteria, which were recently split into the genus bdellovibrio and the newly designated genus bacteriovorax. we determined the 16s rdna sequences of five reference strains and performed a phylogenetic analysis including published 16s rrna sequences of bdellovibrios. a comparison of the secondary structure showed significant differences in two regions of the 16s rrnas of the species bdellovibrio bacteriovo ...	2001	11822674
[interaction of the vegetative and nonculturable forms of salmonella typhimurium with bacteria of the genus bdellovibrio].	the data on the interaction of bacteria of the genus bdellovibrio with the representatives of pathogenic salmonella typhimurium are presented. different types of such interaction are demonstrated: in a two-component system, in fluid media, in an agar layer and on the surface of a solid carrier. as shown for the first time, bdellovibrio cells are capable of interacting not only with actively growing bacteria, but also with their noncultivable forms. the data obtained may serve as the basis for th ...	2001	11881487
design and uses of bdellovibrio 16s rrna-targeted oligonucleotides.	an 18-mer oligonucleotide almost exclusively targeting bdellovibrio spp. was designed based on available 16s rrna sequence data. the specificity of this oligonucleotide used as a pcr primer in combination with a bacteria domain-targeted primer as well as used as a probe in rrna dot blot hybridizations was experimentally confirmed using a variety of alpha-, beta-, gamma-, delta-proteobacteria and gram-positive bacteria. similarly, combinations of the bacteria primer with oligonucleotides targetin ...	2000	10713432
a proposal for the reclassification of bdellovibrio stolpii and bdellovibrio starrii into a new genus, bacteriovorax gen. nov. as bacteriovorax stolpii comb. nov. and bacteriovorax starrii comb. nov., respectively.	bdellovibrios are unique bacteria with the ability to prey upon a wide variety of susceptible gram-negative bacteria. micro-organisms exhibiting this trait have been included in the genus bdellovibrio despite their isolation from diverse habitats and relatively unstudied taxonomic relatedness. in this study, 16s rdna sequences were compared from known terrestrial bdellovibrio species, bdellovibrio bacteriovorus 100t, bdellovibrio stolpii uki2t and bdellovibrio starrii a3.12t in order to study th ...	2000	10826807
prey range characterization, ribotyping, and diversity of soil and rhizosphere bdellovibrio spp. isolated on phytopathogenic bacteria.	thirty new bdellovibrio strains were isolated from an agricultural soil and from the rhizosphere of plants grown in that soil. using a combined molecular and culture-based approach, we found that the soil bdellovibrios included subpopulations of organisms that differed from rhizosphere bdellovibrios. thirteen soil and seven common bean rhizosphere bdellovibrio strains were isolated when pseudomonas corrugata was used as prey; seven and two soil strains were isolated when erwinia carotovora subsp ...	2000	10831412
[study on the plasmid instability of bdellovibrio bdg-9].	a new method system was established in this paper to study the plasmid in stability of bdellovibrio bdg-9. using this system, it was found that when bdg-9 was cultured singly on the smb plate, plasmid pst i was unstable although pst i still replicated and distributed to progeny cell normally. the results showed that the pst i copy number in single cell of bdg-9 decreased gradually to zero with the propagation of bdg-9. additionally, plasmid pst i was very important for the growth of bdg-9, and w ...	2000	12548941
[evaluation of the effect of ecologically hazardous pollutants on the bacteriolytic activity of the predatory bacterium bdellovibrio].	we studied the effect of various concentrations of ecologically hazardous pollutants, urea, phenol, diuron, and cadmium ions, on the physiological activity and survival of the parasitic bacterium bdellovibrio. experiments showed that the survival of bdellovibrios in the presence of the pollutants was two times higher when they were cultivated on agar than when they were cultivated in liquid medium. the data obtained are in agreement with the recent concept of the surface-associated state as a su ...	2000	11315677
high bacterial diversity in permanently cold marine sediments.	a 16s ribosomal dna (rdna) clone library from permanently cold marine sediments was established. screening 353 clones by dot blot hybridization with group-specific oligonucleotide probes suggested a predominance of sequences related to bacteria of the sulfur cycle (43.4% potential sulfate reducers). within this fraction, the major cluster (19.0%) was affiliated with desulfotalea sp. and other closely related psychrophilic sulfate reducers isolated from the same habitat. the cloned sequences show ...	1999	10473405
developmentally regulated protein synthesis during intraperiplasmic growth of bdellovibrio bacteriovorus 109j.	bdellovibrio bacteriovorus 109j is an obligate intraperiplasmic predator of other gram-negative bacteria. collision with a suitable prey cell initiates a developmental sequence ultimately resulting in the destruction of the prey cell and the production of progeny bdellovibrios. two-dimensional gel analysis of patterns of protein synthesis at various times in a synchronously growing culture of bdellovibrio bacteriovorus 109j revealed over 30 polypeptides whose syntheses are developmentally regula ...	1998	9522449
bacterial capsules: no barrier against bdellovibrio.	bdellovibrio bacteriovorus 109j attached to both capsulated and non-capsulated escherichia coli k29 cells. electron microscopy revealed penetration of the thick polysaccharide capsule without any major disintegration of the neighbouring capsular matrix. the capsule remained intact during bdelloplast formation and lysis was unaffected by capsulation of the prey cell. this study shows that, in contrast to its effect on bacteriophage penetration and its protective activities against immune defence ...	1997	9084160
functions of s-layers.	although s-layers are being increasingly identified on bacteria and archaea, it is enigmatic that in most cases s-layer function continues to elude us. in a few instances, s-layers have been shown to be virulence factors on pathogens (e.g. campylobacter fetus ssp. fetus and aeromonas salmonicida), protective against bdellovibrio, a depository for surface-exposed enzymes (e.g. bacillus stearothermophilus), shape-determining agents (e.g. thermoproteus tenax) and nucleation factors for fine-grain m ...	1997	9276929
a comparison of the survival of intraperiplasmic and attack phase bdellovibrios with reduced oxygen	the ability of intraperiplasmic and attack phase bdellovibrios to survive and/or grow under anoxic and microaerobic conditions was examined. both halotolerant and nonhalotolerant bdellovibrio strains were examined. in all instances, the bdellovibrio strains were unable to grow under anoxic conditions, but were able to survive for periods of time in both the extracellular and intraperiplasmic forms. however, the intraperiplasmic organisms were observed to survive longer. increased temperature has ...	1996	8661540
protein uptake into e. coli during bdellovibrio infection. a process of reverse secretion?	bdellovibrio bacteriovorus is a small bacterial parasite that infects other gram-negative bacteria, resides in the periplasm of the host cell, and utilizes host macromolecules as a source of nutrients. evidence is summarized suggesting that b. bacteriovorus secretes proteases and nucleases synthesized in its own cytoplasm that are targeted to the cytoplasm of the host cell. possible mechanisms for this trans-trimembrane protein transport process are discussed.	1994	8276104
translocation of an outer membrane protein into prey cytoplasmic membranes by bdellovibrios.	within minutes of bdellovibrio bacteriovorus attack on prey cells, such as escherichia coli, the cytoplasmic membrane of the prey is altered. sodium dodecyl sulfate-polyacrylamide gel electrophoresis of purified invaded prey cell (bdelloplast) membranes revealed the appearance of a noncytoplasmic membrane protein. this protein is not observed in preparations of noninvaded e. coli membranes and migrates in a manner similar to that of e. coli ompf. isoelectric focusing and two-dimensional gel elec ...	1994	8106336
heat shock-induced axenic growth of bdellovibrio bacteriovorus.	the bdellovibrios are obligately predatory bacteria that attack other gram-negative bacteria. they grow only in the periplasmic space of prey unless they mutate to forms that can grow axenically. a culture medium that promoted enhanced growth of prey-independent bdellovibrios was developed. the ability of this medium to support the growth of prey-dependent bdellovibrios was tested under transcription-altering conditions. this approach tested the hypothesis that the inability to grow prey-depende ...	1993	8458859
effect of bdellovibrio bacteriovorus infection on the phosphoenolpyruvate:sugar phosphotransferase system in escherichia coli: evidence for activation of cytoplasmic proteolysis.	intact cells of bdellovibrio bacteriovorus strain 109j were found to be incapable of taking up 14c-methyl alpha-glucoside, mannitol or fructose, and extracts derived from these cells exhibited negligible activities of the protein components of the phosphoenolpyruvate:sugar phosphotransferase system (pts). escherichia coli strain ml35 cells exhibited high in vivo sugar uptake activities that were progressively lost over a period of 2 h at 30 degrees c following the entry of b. bacteriovorus into ...	1992	1322553
bdellovibrio host dependence: the search for signal molecules and genes that regulate the intraperiplasmic growth cycle.		1992	1522057
acquisition of apparently intact and unmodified lipopolysaccharides from escherichia coli by bdellovibrio bacteriovorus.	the ability of bdellovibrio bacteriovorus to relocalize the ompf major outer membrane porins from its escherichia coli prey to its own outer membranes is diminished in prey expressing smooth lipopolysaccharide (s-lps). since porins exist in the membrane complexed with lps, we examined the lps associated with relocalized porin to determine whether it had been acquired intact, mixed or replaced with bdellovibrio lps, or derivatized by the bdellovibrios. the relocalized trimers were found associate ...	1992	1373716
a conjugation procedure for bdellovibrio bacteriovorus and its use to identify dna sequences that enhance the plaque-forming ability of a spontaneous host-independent mutant.	wild-type bdellovibrios are obligate intraperiplasmic parasites of other gram-negative bacteria. however, spontaneous mutants that can be cultured in the absence of host cells occur at a frequency of 10(-6) to 10(-7). such host-independent (h-i) mutants generally display diminished intraperiplasmic-growth capabilities and form plaques that are smaller and more turbid than those formed by wild-type strains on lawns of host cells. an analysis of the gene(s) responsible for the h-i phenotype should ...	1992	1400153
identification of a bdellovibrio bacteriovorus genetic locus, hit, associated with the host-independent phenotype.	bdellovibrios invade and grow within the periplasmic space of suitable gram-negative bacteria. wild-type bdellovibrios are obligately dependent on host cells for growth, but spontaneous host-independent (h-i) mutants that grow axenically on standard rich culture media can be isolated. such mutants generally retain the ability to grow intraperiplasmically, although the plaques that they produce on lawns of host cells are smaller and more turbid than those produced by wild-type bdellovibrios. here ...	1992	1400154
effect of paracrystalline protein surface layers on predation by bdellovibrio bacteriovorus.	we determined that paracrystalline protein surface arrays (s layers) protected gram-negative eubacteria from predation by bdellovibrio bacteriovorus. aquaspirillum serpens vha and mw5 and aquaspirillum sinuosum were resistant to predation by b. bacteriovorus 6-5-s when fully covered by their s layers. the s layer of aeromonas salmonicida a449 protected the cells from predication by b. bacteriovorus 109j. a predacious, plaque-forming vibrio that lysed an s-layer- variant of caulobacter crescentus ...	1991	2007549
serogrouping of halophilic bdellovibrios from chesapeake bay and environs by immunodiffusion and immunoelectrophoresis.	little has been reported on the serological relationship of halophilic bdellovibrios (bd). immunodiffusion analysis performed with rabbit or mouse bd antisera developed against eight halophilic bd isolates and one terrestrial bd isolate, when reacted with soluble antigen preparations of 45 isolates of halophilic bd, allowed separation into seven serogroups, which were distinct from the terrestrial isolate. soluble antigen preparations of prey bacteria, vibrio parahaemolyticus p-5 (p-5) and esche ...	1991	16348597
formation of stable bdelloplasts as a starvation-survival strategy of marine bdellovibrios.	several wild-type isolates of marine bdellovibrios formed stable bdelloplasts when they infected gram-negative bacterial prey under certain culture conditions. synchronous predator-prey cultures and low nutrient concentrations increased the yield of stable bdelloplasts. the bdellovibrio cells retained in the stable bdelloplasts showed a high survival capacity in nutrient-depleted saline solution (10% viable bdellovibrio cells after 3 months at 25 degrees c), whereas bdellovibrio attack-phase cel ...	1990	16348280
efficiencies of recovery of bdellovibrios from brackish- water environments by using various bacterial species as prey.	a total of 44 bacterial species subdivided into 10 trial experiments have been used as prey for the recovery of bdellovibrios from samples of water from a brackish tidal pond and an aquarium saltwater tank. in an initial investigation, the recovery efficiency of each of the test bacterial species was compared with that of a designated standard prey, vibrio parahaemolyticus p-5. the results revealed that in each case strain p-5 yielded an equal or significantly greater number of plaques of bdello ...	1990	16348096
a new model for the penetration of prey cells by bdellovibrios.	bdellovibrio bacteriovorus 109j and most other bdellovibrios cause prey cells to round following penetration. bdellovibrio sp. strain w does not cause rounding of the prey. analysis of enzyme activities during the early stages of bdellovibrio attack indicated that strain w differs from most other bdellovibrios in that there is no glycanase activity produced during penetration. likewise, heat-killed prey were penetrated normally by strain 109j, but the resulting bdelloplast did not become round a ...	1990	2185219
[artificial immobilization of the two-membered bacterial system bdellovibrio bacteriovorus 109d--escherichia coli b in polyacrylamide gel].	the interaction of a parasite with a host was studied in the two-membered bacterial system, bdellovibrio bacteriovorus 109d and escherichia coli b, immobilised in polyacrylamide gel (paag). the parasite localised inside the host cells was found to be more resistant to the toxic action of paag components than free b. bacteriovorus. the latter lost its mobility and was inactivated in the matrix of the carrier whereas the intracellular parasite had a normal cycle of development in the periplasm of ...	1990	2074852
prey-derived signals regulating duration of the developmental growth phase of bdellovibrio bacteriovorus.	the filamentous elongation typical of growth-phase cells of the predatory bacterium bdellovibrio bacteriovorus is mediated by regulatory signals that are derived from the prey cell itself. these signals regulate the differentiation of growth-phase cells into the attack phase and appear to be required for continued filamentous growth by prey-dependent wild-type bdellovibrios and their prey-independent mutant derivatives alike. using a prey-independent bdellovibrio strain, we have developed an ass ...	1990	2193927
the incidence of bdellovibrio spp. in man-made water systems: coexistence with legionellas.	bdellovibrios have been isolated from surface waters but there are no reports of its occurrence in mains water supplies. one hundred and thirty five water samples from 81 sources were examined for the presence of bdellovibrio bacteriovorus and legionella spp. bdellovibrios were isolated by a double-layer agar technique with two strains of legionella pneumophila serogroup 1 as the host organisms. bdellovibrio spp. were isolated from 57.8% and legionella spp. from 9.5% of the samples. the two spec ...	1990	2398030
unbalanced growth as a normal feature of development of bdellovibrio bacteriovorus.	in this study we have investigated the rates and spatial patterns of chromosome replication and cell elongation during the growth phase of wild-type facultatively prey-independent mutant strains of bdellovibrio bacteriovorus. for the facultatively prey-independent mutants, the total dna content of synchronously growing cultures was found to increase exponentially, as the multiple chromosomes within each filamentous cell replicated simultaneously. cell mass, measured as total cellular protein, al ...	1989	2818131
[research, education and environmental health related to pollution in the gulf].	at italian-russian international conference on "rôle of the university on ecological education and training", was illustrate six topics of 30 years of our scientific and didactic activity on environmental hygiene, here below summarized: i. at first time, sludges of biological treatment plants and domestic sewage were frequently utilized under bacteriological control as economical and ecological fertilizers of land and waters. at present such a custom is very rare owing the chemical pollution of ...	1989	2483627
isolation of the saprophytic strain of mc-3 and participation of the cell surface structure in predation.	from a predatory bacterium, mc-3, a mutant strain which lost predation ability was isolated by chance selection. biological properties of the mutant were the same as the parent except only saprophytic property. properties of the parent and the mutant strains of mc-3, such as bacteriolytic activity of the culture supernatant, digestion of peptidoglycan of the host bacteria, and growth by utilizing the host cells or their cytoplasmic substances, suggested that cell surface structure of the host ce ...	1989	2622396
metabolism of periplasmic membrane-derived oligosaccharides by the predatory bacterium bdellovibrio bacteriovorus 109j.	membrane-derived oligosaccharides (mdo), a class of osmotically active carbohydrates, are the major organic solutes present in the periplasm of escherichia coli and many other gram-negative bacteria when cells are grown in a medium of low osmolarity. analyses of growing cells of bdellovibrio bacteriovorus, a gram-negative predator of other bacteria, have confirmed that they also synthesize a characteristic mdo-like class of oligosaccharides. the natural growth environment of bdellovibrios is the ...	1988	3276663
a soluble enzyme activity that attaches free diaminopimelic acid to bdelloplast peptidoglycan.	an enzyme activity, responsible for the attachment of diaminopimelic acid (dap) to bdelloplast wall peptidoglycan, was studied in an in vitro, cell-free system. most of the activity was found in the high-speed (20000g) supernatant fraction of homogenates of bdelloplasts prepared from a culture of the intracellular bacterium bdellovibrio bacteriovorus 109j, growing synchronously within cells of escherichia coli. peptidoglycan preparations obtained either from e. coli ml35 or from the walls of bde ...	1988	3289615
penicillin-binding proteins of bdellovibrios.	we examined the predacious gram-negative bacterium bdellovibrio bacteriovorous 109j and free-living strains 109j-a1 and 109j-ka1 derived therefrom for penicillin-binding proteins (pbps). we compared their pbps with those of the host bacterium, escherichia coli, and with those of a facultatively predacious bdellovibrio, b. stolpii uki2, grown axenically. the multiple pbps of the 109j strains and of uki2 differed from each other and from those of e. coli, which suggests that screening for pbps may ...	1988	3042760
bdellovibrios: recycling, remodelling and relocalizing components from their prey.	the predatory bdellovibrios acquire all their growth requirements by preying upon other gram-negative bacteria. they reutilize biosynthetic monomers, remanufacture the prey's lipopolysaccharide, and relocalize specific outer membrane proteins from the prey to their own outer membranes. this lifestyle occurs without loss of the biosynthetic potential for axenic growth.	1988	2856309
factors affecting the survival and growth of bacteria introduced into lake water.	the populations of pseudomonas sp. b4, escherichia coli, klebsiella pneumoniae, micrococcus flavus, and rhizobium leguminosarum biovar phaseoli declined rapidly in lake water. the initially rapid decline of the two pseudomonads and r. phaseoli was followed by a period of slow loss of viability, but viable cells of the other species were not found after 10 days. the rapid initial phase of decline was not a result of bdellovibrio spp., bacteriophages, or toxins in the water since bdellovibrio spp. ...	1988	3060035
verification of the protein in the outer membrane of bdellovibrio bacteriovorus as the ompf protein of its escherichia coli prey.	two research groups showed that several bdellovibrio strains incorporated into their outer membranes intact ompf porin proteins derived from their escherichia coli prey. these results could not be reproduced by another group using bdellovibrio bacteriovorus 109j. they showed that a major protein appearing in the bdellovibrio triton x-100-insoluble outer membrane was coded for by the bdellovibrios. we reconciled these results by examining the strain used by this group and by reviving a freeze-dri ...	1987	3542968
[importance of bdellovibrio in regulating microbial cenoses and self-purification processes in domestic sewage].	the bacterial parasite bdellovibrio was directly proved to be involved in the regulation of microbial cenoses and in the self-purification of domestic waste waters. the incidence of heterotrophs, gram-negative bacteria, e. coli and bdellovibrio was followed up in dynamics in the microecological system of waste waters for ten days. in control experiments, bdellovibrions were removed using pteridine as a vibriostatic agent. in the absence of bdellovibrions, the cell number of the studied microorga ...	1987	3329284
[interrelations of bdellovibrios with host bacteria in the coastal zone of the northeastern black sea].		1987	3508938
characterization of bdellovibrio bacteriovorus bacteriophage mac-1.	the bacteriophage mac-1, which specifically infects bdellovibrio bacteriovorus, was plaque purified and raised to high titre. the phage was purified by nacl/polyethylene glycol precipitation, followed by two cycles of isopycnic density gradient centrifugation in cscl. the purified phage exhibited a density of 1.363 g cm-3 and a sedimentation coefficient of 94s. nucleic acid isolated from purified phage was resistant to hydrolysis under alkaline conditions and to digestion with rnaase, but it was ...	1987	3446745
[intracellular development of bdellovibrio bacteriovorus].	the intracellular growth of bdellovibrio bacteriovorus, a bacterial parasite, was studied by a light-optical method using time-lapse cinemicrography. the organism was found to be capable of growth in the periplasmic space of filamentous cells of the host bacterium pseudomonas fluorescens without any contact with the cytoplasmic membrane. several b. bacteriovorus cells could grow simultaneously in the bdelloplasm.	1986	3102907
an atp transport system in the intracellular bacterium, bdellovibrio bacteriovorus 109j.	the intracellularly growing bacterium bdellovibrio bacteriovorus 109j transports intact atp by a specific, energy-requiring process. atp transport does not involve either an adp-atp or an amp-atp exchange mechanism but, instead, has characteristics of an active transport permease. kinetically distinct systems for atp transport are expressed by the two developmental stages of the bdellovibrio life cycle.	1986	3745115
predatory prokaryotes: predation and primary consumption evolved in bacteria.	two kinds of predatory bacteria have been observed and characterized by light and electron microscopy in samples from freshwater sulfurous lakes in northeastern spain. the first bacterium, named vampirococcus, is gram-negative and ovoidal (0.6 micrometer wide). an anaerobic epibiont, it adheres to the surface of phototrophic bacteria (chromatium spp.) by specific attachment structures and, as it grows and divides by fission, destroys its prey. an important in situ predatory role can be inferr ...	1986	11542073
comparative biology of intracellular parasitism.		1985	3900672
waveform analysis and structure of flagella and basal complexes from bdellovibrio bacteriovorus 109j.	the structure of sheathed flagella from bdellovibrio bacteriovorus was investigated. the first three periods of these flagella were characterized by progressively smaller wavelengths and amplitudes in periods more distal to the cell. the damped appearance was due to a single nonrandom transition between two helical structures within each filament. the intersection of the two helices, one of which was a threefold-reduced miniature of the other, occurred at a fixed distance along the filament and ...	1985	4030690
uptake of intact nucleoside monophosphates by bdellovibrio bacteriovorus 109j.	the degraded nucleic acids and ribosomes of its prey cell provide bdellovibrio bacteriovorus 109j with a source of ribonucleoside monophosphates and deoxyribonucleoside monophosphates for biosynthesis and respiration. we demonstrate that bdellovibrios, in contrast to almost all other bacteria, take up these nucleoside monophosphates into the cell in an intact, phosphorylated form. in this way they are able to assimilate more effectively the cellular contents of their prey. studies with ump and d ...	1985	4030692
isolation and composition of sheathed flagella from bdellovibrio bacteriovorus 109j.	a procedure was developed for the purification of sheathed flagella from bdellovibrio bacteriovorus 109j. preparations of isolated flagella appeared as filaments 28 nm in diameter, did not vary in sheath content by more than 10% from the mean, and contained 50% protein, 38% phospholipid, and 12% lipopolysaccharide (lps) by weight. the sheath was readily solubilized by triton x-100, whether or not edta was present, and contained all of the lps and phospholipid and 30 to 40% of the protein of the ...	1985	4030691
bdellovibrio bacteriovorus synthesizes an ompf-like outer membrane protein during both axenic and intraperiplasmic growth.	outer membrane preparations of bdellovibrio bacteriovorus grown intraperiplasmically on escherichia coli containing ompf were prepared by the triton x-100 procedure of schnaitman (j. bacteriol. 108:545-552, 1971). they contained a protein that migrated to almost the same position as e. coli ompf in sodium dodecyl sulfate-acrylamide gradient gel electrophoresis and to the same position as e. coli ompf when urea was incorporated into the gel. the mobility of this protein increased relative to that ...	1985	4019410
permeability of the boundary layers of bdellovibrio bacteriovorus 109j and its bdelloplasts to small hydrophilic molecules.	measurements of the sucrose-permeable and -impermeable volumes during bdellovibrio bacteriovorus attack on escherichia coli or pseudomonas putida showed that the volume of the bdelloplast increased over that of the substrate cell. although the pattern of the increase differed with the two organisms, the volumes reached maximum at about 60 min into the bdellovibrio growth cycle. by this time, the cytoplasmic membranes of the attacked cells were completely permeable to sucrose. the kinetics of inc ...	1984	6363383
[oscillations in population densities of the bacterial prey-predator couple escherichia coli-bdellovibrio bacteriovorus: experimental study and theoretical model].	oscillations in population densities in the bacterial predator-prey bdellovibrio bacteriovorus-escherichia coli system were investigated both experimentally and theoretically. experimental conditions for observing (damped) oscillations were first determined in a closed system and then used in an open system, i.e. in a chemostat, when an adequate flux of nutritive medium was added. the experimentally observed oscillations were always unstable with poorly reproducible amplitude and period. a theor ...	1984	6372581
distribution of bdellovibrios in the water column of an estuary.	the distribution of bdellovibrios in the water column of the miles river has been studied. water samples were collected every 4 h over a 24-h period from five depths in the water column. the samples were cultured for the recovery of bdellovibrios lytic against vibrio parahaemolyticus. environmental parameters, i.e., salinity, temperature, turbidity, and dissolved oxygen (do) were measured for each sample. bdellovibrios were observed to be uniformly distributed at all depths measured in the water ...	1984	6478316
[distribution of bdellovibrio bacteriovorus in river water with different degrees of bacterial contamination].		1984	6519506
acquisition of escherichia coli outer membrane proteins by bdellovibrio sp. strain 109d.	the ability of bdellovibrio sp. to acquire the ompf major outer membrane protein from its escherichia coli prey was examined to determine if there were other outer membrane proteins which could or could not be acquired. growth of bdellovibrios on mutant prey which were defective in the expression of outer membrane proteins revealed that bdellovibrio sp. could acquire the ompc protein in the absence of the ompf protein. however, the ompa, lamb, and protein 2 proteins could not be found in the bde ...	1984	6376474
[role of carbohydrate-protein recognition in the process of bdellovibrio attaching to bacterial host cells].	the authors discuss the role of carbohydrates in the surface layer of the cell wall in the process of bdellovibrio attachment to host-bacteria cells. the paper presents the results of inhibitory analysis using sugars conducted with two model systems as well as the data about the effectiveness of the interaction between parasite cells and host cells after the modification of their surface polysaccharide layer with concanavalin a and sodium periodate.	1984	6090874
attachment of diaminopimelic acid to bdelloplast peptidoglycan during intraperiplasmic growth of bdellovibrio bacteriovorus 109j.	an early event in the predatory lifestyle of bdellovibrio bacteriovorus 109j is the attachment of diaminopimelic acid (dap) to the peptidoglycan of its prey. attachment occurs over the first 60 min of the growth cycle and is mediated by an extracellular activity(s) produced by the bdellovibrio. some 40,000 dap residues are incorporated into the escherichia coli bdelloplast wall, amounting to ca. 2 to 3% of the total initial dap content of its prey cells. incorporation of dap occurs when e. coli, ...	1984	6202674
change in the surface hydrophobicity of substrate cells during bdelloplast formation by bdellovibrio bacteriovorus 109j.	during intraperiplasmic growth of bdellovibrio bacteriovorus 109j, the substrate cell surface becomes more hydrophobic. this was shown (i) by comparing the sensitivity to hydrophobic antibiotics of wild-type and lipopolysaccharide mutant strains of salmonella typhimurium to that of the bdellovibrio growing on these strains and (ii) by measuring the binding efficiency of these strains, escherichia coli, and their derived bdelloplasts to octyl sepharose. the kinetics of increase in surface hydroph ...	1984	6363384
alternative prey: a mechanism for elimination of bacterial species by protozoa.	antibiotic-resistant strains of salmonella typhimurium and klebsiella pneumoniae died readily after their addition to raw sewage, but they grew in sterilized sewage. the decline was not a result of abiotic stresses, and because the bacteria were able to survive in large numbers for at least 15 days in solutions containing no organic nutrients, it was not a result of competition. toxin production, bacteriophages, and bdellovibrio sp. did not cause the disappearance of the two bacterial species. a ...	1983	6418072
peculiarities of the fatty acid composition of bdellovibrio.	the fatty acid composition of twelve bdellovibrio strains isolated upon the growth on bacteria of various taxonomic groups was studied. a dependence of the lipid composition of bdellovibrios on that of bacteria they were parasitizing on was shown. data pointing to the selective incorporation of fatty acids of host bacteria by bdellovibrios were obtained. bdellovibrio membranes were shown to contain monounsatured fatty acids with different positions of double bonds indicating that there are at le ...	1983	6403417
differentiation after premature release of intraperiplasmically growing bdellovibrio bacteriovorous.	bdellovibrio bacteriovorous attacks and penetrates other gram-negative bacteria, creating a growth chamber termed a bdelloplast. we have found that exposing the bdelloplasts to edta, followed by treatment with a lytic enzyme concentrate derived from bdellovirio cultures, prematurely released the intraperiplasmically growing bdellovibrios at any time during their growth cycle. upon release, the growth-form bdellovibrios terminated any initiated rounds of dna synthesis and differentiated into moti ...	1983	6403505
[method of determining the pteridine sensitivity of parasitic bacteria of the genus bdellovibrio].	the method of determination of parasitic bacteria bdellovibrio sensitivity to pteridine has been described. the method suggested can be used in research work for diagnostics of bdellovibrio genus bacteria.	1983	6882836
[factors affecting the participation of bacteria of the genus bdellovibrio in the self-purification processes in the syr darya river].	the effect of season, temperature and abundance of microflora on the interrelations between bdellovibrions and host-bacteria in the syr daryo river compared with the oka has been studied. these factors and composition of allochthonic gram-negative bacteria in the river influence on the abundance of bdellovibrio and extent its participation in the self-purification of basins.	1983	6882839
biosynthesis of oxygen-detoxifying enzymes in bdellovibrio stolpii.	axenically grown bdellovibrio stolpii (i.e., grown independently of the host) was examined for superoxide dismutase, catalase, and peroxidase activities. kinetics of enzyme synthesis were determined for aerobically grown cultures and for cultures exposed to 100% oxygen. enzymatic activities varied with the age of the culture. normally grown cultures exhibited maximum activity during the first 10 h of growth and again as the stationary phase was approached, beginning at about 48 h. polyacrylamide ...	1982	6290452
periplasmic enzymes in bdellovibrio bacteriovorus and bdellovibrio stolpii.	when cells of either bdellovibrio bacteriovorus 109j or bdellovibrio stolpii uki2 were subjected to osmotic shock by treatment with sucrose-edta and mgcl2 solutions, only trace amounts of proteins or enzyme activities were released into the shock fluid. in contrast, when nongrowing cells were converted to motile, osmotically stable, peptidoglycan-free spheroplasts by penicillin treatment, numerous proteins were released into the suspending fluid. for both species, this suspending fluid contained ...	1982	6124531
seasonal distribution of bdellovibrios at the mouth of the patuxent river in the chesapeake bay.	water samples taken at monthly intervals from three sites in the mouth of the patuxent river in the chesapeake bay were cultured for bdellovibrios lytic to vibrio parahaemolyticus and for total viable bacterial counts. the number of bdellovibrios recovered decreased from the spring months (april, may, june (amj) until very few were detected during the winter months (january, february, march (jfm), which also coincided with the lowest water temperatures. during the amj season there was a signific ...	1982	7066762
lytic activity of bdellovibrio bacteriovorus against bacteria of the family legionellaceae.	a lytic activity of bdellovibrio bacteriovorus strains 6-5-s and 12 was found to be present, against representatives of three legionella species: legionella pneumophila-strains knoxville 1 (serogroup 1), togus 1 (serogroup 2), bloomington 2 (serogroup 3) and los angeles 1 (serogroup 4); legionella micdadei-strain tatlock; legionella bozemanii-strain wiga, as well as against strains of legionella pneumophila isolated in bulgaria-draginovo 1, 2, 3-belonging to serogroup 1. it is suggested that b. ...	1982	7124158
molecular parasitism in the escherichia coli-bdellovibrio bacteriovorus system: translocation of the matrix protein from the host to the parasite outer membrane.	during the intracellular maturation in escherichia coli of the parasite bdellovibrio bacteriovorus the outer membrane, major protein i of e. coli (i.e., the matrix protein) becomes associated with the outer membrane of the emerging parasite cells. the binding properties of this protein with the outer membrane of the host and of the parasite are identical. an analogous phenomenon also occurs during bdellovibrio parasitism on klebsiella pneumoniae and on salmonella typhimurium. possible roles for ...	1982	6765198
[importance of detecting bdellovibrio bacteriovorus in the reservoir water].		1981	7239234
incorporation of substrate cell lipid a components into the lipopolysaccharide of intraperiplasmically grown bdellovibrio bacteriovorus.	the composition of bdellovibrio bacteriovorus lipopolysaccharide (lps) was determined for cells grown axenically and intraperiplasmically on escherichia coli or pseudomonas putida. the lps of axenically grown bdellovibrios contained glucose and fucosamine as the only detectable neutral sugar and amino sugar, and nonadecenoic acid (19:1) as the predominant fatty acid. additional fatty acids, heptose, ketodeoxyoctoic acid, and phosphate were also detected. lps from bdellovibrios grown intraperipla ...	1981	7024249
partial characterization of lipid a of intraperiplasmically grown bdellovibrio bacteriovorus.	the lipid a components of substrate cell origin incorporated by bdellovibrio bacteriovorus during intraperiplasmic growth (d. r. nelson and s. c. rittenberg, j. bacteriol. 147:860-868, 1981) were shown to be integrated into its lipopolysaccharide structure. lipid a isolated from bdellovibrios grown on escherichia coli was resolved into two fractions by thin-layer chromatography. fraction 2 had the same rf as the single lipid a fraction of axenicaly grown bdellovibrios, and both stained identical ...	1981	7024250
protein composition of bdellovibrio bacteriovorus and escherichia coli membranes during their interaction.	a comparative study of membrane proteins of bdellovibrio bacteriovorus and host-bacteria escherichia coli was performed by polyacrylamide gel electrophoresis in presence of sodium dodecyl sulphate. infection of e. coli cells by bdellovibrions resulted in the loss of some high-molecular proteins and appearance of new ones in the host-bacteria membranes. the possible role of parasite proteases in degradation of host-bacteria membrane proteins is discussed.	1981	7013349
[theoretical model of the predator-prey interaction kinetics between "bdellovibrio bacteriovorus" and "escherichia coli" (author's transl)].	a theoretical model is suggested in order to explain the main features of the interaction kinetics between the micropredator bdellovibrio bacteriovorus and its prey escherichia coli. three parametes are used in this model: the incubation time t, the fixation rate constant k, and the predator multiplication factor a. their values can be determined from the experimental variations of the total predator concentration p, and the total density of preys (c + c'). an experimental study of the predation ...	1981	7036823
[comparative characteristics of the bdellovibrio strains isolated from river water and sewage].	the morphology, the host ranges, the resistance to pteridine and the nucleotide composition of dna were compared in 12 newly isolated and 10 collection strains of bdellovibrio. the significance of properties used for the taxonomy of these organisms was evaluated. the host ranges of bdellovibrio strains are heterogeneous with respect to the taxonomy of host bacteria. the specificity of the parasite depends to a significant degree on the host bacterium in which it grows. all the strains including ...	1981	7242394
[participation of bdellovibrios in sewage self-purification processes].	the participation of bacterial parasites belonging to the genus bdellovibrio in the processes of sewage self-purification was studied in refineries of pushchino. the lytic activity of bdellovibrio resulting in a decrease of the number of heterotrophic gram-negative bacteria and e. coli in sewage was found to depend on the temperature factor influencing the intensity of interaction between the parasite and the host bacterium. the maximal p/h (parasite/host) index was found at the water temperatur ...	1981	7012553
pyrimidine metabolism of bdellovibrio bacteriovorus grown intraperiplasmically and axenically.	bdellovibrio bacteriovorus grown axenically or intraperiplasmically on escherichia coli has pathways for the interconversion of pyrimidines and the synthesis of pyrimidine nucleoside 5'-triphosphates similar to those found in the enteric bacteria. minimal differences in enzyme activities were observed for axenically and intraperiplasmically grown cells. as might be expected for an organism which takes up deoxyribonucleoside 5'-monophosphates per se, high levels of enzymes which catalyze the gene ...	1981	6260736
[comparative study of the membrane protein composition of bacteria in the genus bdellovibrio].	the protein composition of membranes was studied in 17 bdellovibrio strains by electrophoresis in polyacrylamide gel in the presence of sodium dodecyl sulfate. no similarity in the protein composition of membranes was found in the strains grown on cells of one and the same host. a dendrogram constructed basing on the similarity coefficients between the strains allowed to subdivide them into 3 groups according to the protein composition of their membranes. this correlated with the other phenotypi ...	1981	7329359
fungicide enhancement of nitrogen fixation and colonization of phaseolus vulgaris by rhizobium phaseoli.	the number and weight of pods and the weight and nitrogen content of the tops of beans (phaseolus vulgaris) derived from seeds inoculated with a thiram-resistant strain of rhizobium phaseoli were increased if the seeds were treated with thiram before sowing in soil. a greater percentage of the nodules on 21-day-old plants were derived from the resistant strain, more nodules were formed, and these nodules were more effective in the presence of the fungicide than in its absence. these differences ...	1981	16345715