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PubMedDate not supplied

[Ectothiorhodosinus mongolicum gen. nov., sp. nov.,--a new purple sulfur bacterium from soda lake in Mongolia].

A new purple sulfur bacterium (strain M9) was isolated from the steppe soda Lake Dzun Uldziin Nur (pH 9.4; mineralization, 3.3%) situated in southeastern Mongolia. Individual cells appear as vibrios 0.3-0.5 x 0.7-1 micron in size. The dividing cells often do not separate from each other, forming an almost closed ring. The internal photosynthetic membranes are represented by concentric lamellae lining the cell wall. Photosynthetic pigments are bacteriochlorophyll a and carotenoids of the spirilloxanthin series. The main carotenoid (> 96%) is spirilloxanthin. Two typical light-harvesting complexes (LH1 and LH2) are present in the membranes in a 1:1 ratio. The bacterium is an anaerobe and facultative photoorganoheterotroph. Photolithoautotrophic growth on sulfide is scarce. Thiosulfate is utilized as an electron donor only in the presence of organic matter. Globules of elemental sulfur are formed as an intermediary product of sulfide and thiosulfate oxidation and are deposited outside the cells. The end product of oxidation is sulfate. In the presence of sulfide and carbonates, acetate, lactate, malate, pyruvate, propionate, succinate, and fumarate are used as the additional sources of carbon in anoxygenic photosynthesis. Vitamin are not required. The bacterium is an alkaliphile the pH optimum is at 8.3-9.1, the pH range is 7.6-10.1. The optimum NaCl concentration in the medium is 1 to 7%; the range is 0.5 to 0.9%. The optimum carbonate content in the medium is 2%; the range is 1 to 10%. The best growth occurs at 30-35 degrees C. The DNA G + C content is 57.5 mol%. According to the results of analysis of the 16S rRNA gene sequences, the new isolate M9 belongs to the phylogenetic cluster containing representatives of the family Ectothiorhodospiraceae within the class "Gammaproteobacteria." In this class, the new isolate forms a new branch, which occupies an intermediate position between the representatives of the genera Ectothiorhodospira and Thiorhodospira. Based on the phenotypic and genetic characteristics, the new purple sulfurbacterium was assigned to a new species of a new genus of the family Ectothiorhodospiraceae, Ectothiorhodosinus mongolicum gen. nov., sp. nov.

Anaerobiosis↗
PubMed2004

[Effect of organophosphorous insecticides on Chinese chive insect pests and their degradation by pesticide-degrading bacterium].

3.00 kg(a. i) x hm(-2) phoxin and 2.63 kg(a. i) x hm(-2) methyl parathion were respectively applied to control the Taeniothrips alliorum on Chinese chive. Compared to no pesticide treatment, the decline rate of the insect density was 98.28% and 98.39% at the 3rd day after spraying pesticides, and 89.94% and 94.04% at the 20th day after spraying pesticides, respectively. At the 3rd day after spraying 15.00, 18.00 and 21.00 kg(a. i) x hm(-2) phoxin, the insect density of Bradysia odoriphaga decreased 80.77%, 93.10% and 96.98%, and at the 35th day after spraying, it decreased 92.44%, 95.05% and 96.81%, respectively. The application of pesticide-degrading bacterium had not any effect on controlling insect pests, but could markedly degrade pesticide. At the 3rd day after spraying 45.00 L x hm(-2) pesticide-degrading bacterium to control Taeniothrips alliorum, the degradion rate of phoxin and methyl parathion was 99.52% and 98.83%, and at the 3rd after spraying 75.00 L x hm(-2) pesticide-degrading bacterium to control Bradysia odoriphaga, the degradation rate of three concentrations of phoxin was 100%, 100% and 99.69%, respectively.

Animals↗
PubMed2004

[Study on anti-bacterium activity of ginkgolic acids and their momomers].

OBJECTIVE: Ginkgolic acids and their three monomers were separated from ginkgo sarcotestas. The anti-bacterium activity of ginkgolic acids were tested. The relation between the anti-bacterium activity and side chain of ginkgolic acid were studied. METHOD: The MIC of ginkgolic acids and their three monomers and salicylic acid were tested. RESULTS: Ginkgolic acid has strong inhibitive effect on G+-bacterium. Salicylic acid has no side chain, so no anti-bacterial activity. When the length of gingkolic acid side chain is C13:0, it has the strongest anti-bacterial activity in three monomers. CONCLUSION: The side chain of ginkgolic acid is the key functional group that possessed anti-bacterial activity. The length of Ginkgolic acid was the main effective factor of anti-bacterial activity.

Anti-Bacterial Agents↗
PubMed2005

The algae-lytic ability of bacterium DC10 and the influence of environmental factors on the ability.

A lysing-bacterium DC10, isolated from Dianchi Lake of Yunnan Province, was characterized to be Pseudomonas sp. It was able to lyse some algae well, such as Microcystis viridis, Selenastrum capricornutum, and so on. In this study, it was shown that the bacterium lysed the algae by releasing a substance; the best lytic effects were achieved at low temperatures and in the dark. Different concentrations of CaCl2 and NaNO3 influenced the lytic effects; the ability to lyse algae decreased in the following order: pH 4 > pH 9 > pH 7 > pH 5.5. It was significant to develop a special technology with this kind of bacterium for controlling the bloom-forming planktonic microalgae.

Calcium Chloride↗
PubMed2003

[Isolation and characterization of a novel radiation-resistant rod-shaped bacterium].

A novel radiation-resistant bacterium was isolated from soil of lake bank in Beijing. The bacterium produced orange-pigmented colonies and formed rod-shaped cells that stained gram negative alike the Deinobacter grandis previously described by Japan's scientist. It was found with electron microscopy that the isolate is of 0.6 microm - 1.6 microm size and has a 30-40 nm thickness of cell wall, being slightly larger and thicker than the Deinobacter grandis. There was a difference in the concentration and molecule weight of catalase between the isolate and the Deincoccus radiodurans R1. The deoxyribonucleic acid guanine plus cytosine (G + C) base ratio was 70.7 mol%. 16S RNA gene sequencing also showed that this rod-shaped bacterium possessed a high homology with the Deinobacter grandis, suggesting that it might be classified into the genus Deinobacter and constitute a new species in this genus.

Bacterial Proteins↗
PubMedDate not supplied

[The new facultatively chemolithoautotrophic, moderately halophilic, sulfate-reducing bacterium Desulfovermiculus halophilus gen. nov., sp. nov., isolated from an oil field].

The new mesophilic, chemolithoautotrophic, moderately halophilic, sulfate-reducing bacterium strain 11-6 could grow at a NaCl concentration in the medium of 30-230 g/l, with an optimum at 80-100 g/l. Cells were vibrios motile at the early stages of growth. Lactate, pyruvate, malate, fumarate, succinate, propionate, butyrate, crotonate, ethanol, alanine, formate, and H2 + CO2 were used in sulfate reduction. Butyrate was degraded completely, without acetate accumulation. In butyrate-grown cells, a high activity of CO dehydrogenase was detected. Additional growth factors were not required. Autotrophic growth occurred, in the presence of sulfate, on H2 + CO2 or formate without other electron donors. Fermentation of pyruvate and fumarate was possible in the absence of sulfate. Apart from sulfate, sulfite, thiosulfate, and elemental sulfur were able to serve as electron acceptors. The optimal growth temperature was 37 degrees C; the optimum pH was 7.2. Desulfoviridin was not detected. Menaquinone MK-7 was present. The DNA G+C content was 55.2 mol %. Phylogenetically, the bacterium represented a separate branch within the cluster formed by representatives of the family Desulfohalobiaceae in the subclass Deltaproteobacteria. The bacterium was assigned to a new genus and species, Desulfovermiculus halophilus gen. nov., sp. nov. The type strain is 11-6T (= VKM B-2364), isolated from the highly mineralized formation water of an oil field.

Carboxylic Acids↗
PubMedDate not supplied

[Isolation and characterization of a unicellular manganese-oxidizing bacterium from a freshwater lake in northwestern Russia].

A unicellular manganese-oxidizing bacterium (strain L7), isolated from Lake Ladoga, is identified as "Siderocapsa" sp. according to its morphology. However, this bacterium belongs to the phylogenetic cluster of Pseudomonas putida. The physiological characteristics (utilization of sugars, polyatomic alcohols, organic acids, and phenolic substrates as carbon and energy sources) also indicate the similarity of strain L7 to representatives of the genus Pseudomonas. The growing culture oxidizes Mn(II); the rate of oxidation depends on the type of added organic substrate. Carbonate requirement for this process indicates mixotrophic metabolism. The relatedness of the isolated bacterium to the representatives of the genus Pseudonomas and their phenotypic similarity provide a basis for considering strain L7 not as "Siderocapsa" sp., but as a new species, Pseudomonas siderocapsa sp. nov., of the P. putida cluster.

Fresh Water↗
PubMed2006

[Isolation, identification and phylogenetic analysis of a pathogenic bacterium in channel catfish].

A pathogenic bacterium (CCF00024) was isolated from the kidney and liver of the diseased channel catfish with acute epidemic disease. Artificial infection proved that the bacterium was the pathogen of the disease. Its morphological, physiological, biochemical characteristics and 16S rDNA sequence analysis were studied. The isolated strain is an aerobic, non-fermentative bacterium. The bacteria are gram negative, rods, with polar multi-flagella; Oxidase-negative, methyl-red-negative, lysine decarboxylase-positive, DNAase-positive, urease-positive, lipase-positive and protease-positive. The bacteria can't utilize most of sugars with production of acid, except maltose and mannose. A phylogenetic tree was constructed by comparing the 16S rDNA sequence of the isolated strain (GenBank accession number AY970826) with other relative bacteria species in the RDP and GenBank databases. In the phylogenetic tree CCF00024, Stenotrophomonas maltophilia 13637T, Stenotrophomonas maltophilia MG958T, and Stenotrophomonas maltophilia M5-1 constitute a branch. The similarity value between strain CCF00024 and those 5 strains Stenotrophomonas maltophilia are 99.4%-99.6%. According to morphological, physiological, biochemical characteristics and phylogenetic analysis, the isolated strain (CCF00024) is identified as Stenotrophomonas maltophilia.

Animals↗
PubMed1988

Reaction of bacterium-primed murine T cells to cartilage components: a clue for the pathogenesis of arthritis?

Although different models for rheumatoid arthritis have been studied, the pathogenesis in humans remains unknown. A possible mechanism is the crossreactivity between bacterial components and the target-tissue, the cartilage. The existence of this crossreactivity is supported by various data from clinical and experimental studies. Here we provide direct evidence that priming in vivo with cell wall fragments of Streptococcus pyogenes or Escherichia coli can induce a cellular and humoral anti-cartilage response in Balb/c mice in vitro. T cells isolated from these mice can be stimulated in vitro to proliferate by a variety of antigens among which are the priming bacterium, an unrelated bacterium, small bacterial components and diverse antigens of cartilagenous origin. In bacterium-primed mice antibodies were also detected that displayed a reactivity to cartilage extract besides the reactivity to bacteria. A crossreactive response occurred in vivo in certain circumstances: a delayed type hypersensitivity reaction could be elicited in cell-wall-primed mice by challenge with cartilage extract. For the expression of this crossreactive response in vivo however, it was obligatory to attenuate the mouse's suppressor-circuit. In this paper we would suggest a mechanism for the pathology of chronic arthritis, based on repeated challenges with different bacterial stimuli.

Animals↗
PubMed1987

[The isolation, classification and some physiological properties of a protease-producing bacterium].

A proteolytic bacterium was isolated from specimen collected from soil. The protease producing bacterium showed optimal growth in media with neutral pH and when incubated at 30 degrees C aerobically. According to the classification results, the gram (+), sporulating bacillus was a Bacillus genus member. Also some physiological properties of the isolated bacterium was determined.

Aerobiosis↗
PubMed1987

Experimental infection and abortion of pregnant guinea pigs with a unique spirillum-like bacterium isolated from aborted ovine fetuses.

Study was made of the pathogenicity of a spirillum-like, anaerobic, gram-negative bacterium, originally isolated from aborted lambs, for pregnant guinea pigs. Reproducible conditions for propagation and preservation of the bacterium were determined as requisite for the preparation of cultures for animal inoculation. A preliminary experiment was done with 10 pregnant guinea pigs to test for an infective dose of organisms that would produce abortion. High-passage cultures (n = 50) were used to inoculate these guinea pigs intraperitoneally. Six of 10 guinea pigs aborted, and the organism was cultured from fetal tissues of 5 guinea pigs. Isolates from 3 of the 6 guinea pigs were propagated through 4 passages on blood agar and used to infect 3 groups, each of 5 guinea pigs. A 4th group of 5 guinea pigs was inoculated with the original culture. Three of 5 animals in the first 3 groups, which had been given the low-passage cultures from the preliminary trial, and 2 of 5 guinea pigs in the 4th group, which had been given the original culture, aborted. Antibody against the spirillum was detected in 19 of 30 inoculated guinea pigs. The major microscopic lesions were acute suppurative placentitis and splenitis. This bacterium retained pathogenic properties sufficient to cause infection, abortion, and microscopic lesions in two-thirds of the guinea pigs, in spite of high in vitro passage. The organism has unique ultrastructures, and its genus and species are yet to be determined.

Abortion, Veterinary↗
PubMed1985

The biosynthesis and assembly of methanol dehydrogenase in bacterium W3A1.

Bacterium W3A1, a restricted facultative methylotroph, produces a periplasmic methanol dehydrogenase composed of two identical subunits of Mr = 57,300, and two noncovalently bound methoxatin prosthetic groups. A precursor form of Mr = 1,500 larger than the mature subunit was identified among the products of an in vitro translation of total RNA isolated from bacterium W3A1. The precursor form of the protein could not be detected in cells during in vivo pulse-labeling studies, suggesting that the processing of this precursor occurs entirely co-translationally. Whereas the holoenzyme was detectable only as a dimer, removal of the prosthetic group yielded an apoenzyme that could be detected as either a dimeric or monomeric species. After readdition of the purified prosthetic group to the apoenzyme, only the dimeric form of the protein, bearing the cofactor and exhibiting an absorption spectrum similar to that of the holoenzyme, was detected. Neither the mature apoprotein nor the holoenzyme demonstrated any affinity for phospholipid membranes, as assayed by their inability to bind to liposomes. Taken together, these data suggest a scheme of co-translational processing and export of the apoprotein subunits, followed by assembly of the subunits and prosthetic groups in the periplasmic space to form the mature holoenzyme. The suitability of bacterium W3A1, and other methylotrophic bacteria, for use in studies of protein biosynthesis and export, is also discussed.

Alcohol Oxidoreductases↗
PubMedDate not supplied

[New classification of bacterium (author's transl)].

The Author proposes a new classification of bacterium. It has been drawn up with the acquisitions of these last years regarding morfological, physiological and ecological characteristics and genetics of bacterium. It is also based on a new biological concept of the species, which is valid both for the "procarioti" and for the "eucarioti". Such a new concept, in time, makes a really new natural classification of the bacterium possible. Therefore the classification proposed here does not want to be nor must it be considered complete. It has been formed to be dynamic, capable that is of being modified as knowledge progresses.

Bacteria↗
PubMed1994

Assembly of redox centers in the trimethylamine dehydrogenase of bacterium W3A1. Properties of the wild-type enzyme and a C30A mutant expressed from a cloned gene in Escherichia coli.

In trimethylamine dehydrogenase, the enzyme-bound FMN is covalently linked to Cys-30 by a 6-S-cysteinyl FMN bond. The role played by this bond in catalysis has been investigated using a recombinant wild-type trimethylamine dehydrogenase and a Cys-30 to Ala-30 mutant, both expressed from a cloned gene (tmd) in the heterologous host Escherichia coli. The recombinant wild-type and C30A enzymes were found to be quantitatively associated with the 4Fe-4S center and ADP which are both present in the enzyme isolated from bacterium W3A1. In contrast to the enzyme isolated from bacterium W3A1, however, both recombinant proteins contained less than stoichiometric amounts of flavin and were refractory to reconstitution by FMN. The FMN in the recombinant wild-type enzyme was shown to be covalently linked to the protein, and the enzyme possessed catalytic properties similar to its counterpart isolated from bacterium W3A1. It is envisaged that flavinylation proceeds via a nucleophilic attack by the thiolate of Cys-30 at C-6 of the isoalloxazine ring of enzyme-bound FMN. The C30A mutant was found to bind FMN noncovalently and to also catalyze the demethylation of trimethylamine. The major effect of removing the 6-S-cysteinyl FMN bond is to raise the apparent Km for trimethylamine by 2 orders of magnitude and to diminish the apparent kcat for the reaction by only a factor of 2. Therefore, the 6-S-cysteinyl FMN bond is not essential for catalysis, but it is required for efficient functioning of the enzyme at micromolar concentrations of substrate.

Adenosine Diphosphate↗
PubMed2026

Draft genome sequence of the agarolytic bacterium Cellvibrio sp. 25HG11W-0.

Cellvibrio sp. strain 25HG11W-0 is a freshwater agarolytic bacterium isolated from the Namyangcheon stream in the Republic of Korea. Here, we report the draft genome sequence of this bacterium, which harbors multiple putative agarase genes belonging to glycoside hydrolase (GH) families GH16, GH50, GH86, and GH117.

Cellvibrio↗
PubMed2000

Intestinal inflammatory pseudotumour with regional lymph node involvement: identification of a new bacterium as the aetiological agent.

Inflammatory pseudotumours are the morphological expression of diverse processes such as reactive/reparative, infective, and neoplastic. This paper reports an example of intestinal inflammatory pseudotumour, with identification of a newly characterized bacterium in the lesion. The patient presented with intestinal obstruction. Laparotomy revealed a tumour in the terminal ileum causing stricture, and multiple enlarged regional lymph nodes. Histologically, the tumour and lymph nodes were composed of plump spindle cells disposed in a vague storiform pattern, and associated with lymphocytes and plasma cells. Immunohistochemical studies showed that most of the spindle cells were histiocytes (CD68 positive), prompting a search for a bacterial aetiology, akin to mycobacterial spindle cell pseudotumour. All histochemical stains for micro-organisms were unrewarding. Ultrastructural studies, however, revealed abundant bacteria within the spindle histiocytes. Polymerase chain reaction, using conserved oligonucleotide primers complementary to the 16S rRNA genes of eubacteria, was employed to amplify 16S rRNA gene fragments directly from the involved lymph node tissue. Phylogenetic analysis of the amplified DNA sequences revealed an organism with 99% sequence conformity to Pseudomonas veronii, a bacterium which has hitherto not been implicated in human infection. The importance of searching for an infective agent in inflammatory pseudotumour in the appropriate setting is re-emphasized.

Granuloma, Plasma Cell↗
PubMed1997

The cost of antibiotic resistance--from the perspective of a bacterium.

The possession of an antibiotic resistance gene clearly benefits a bacterium when the corresponding antibiotic is present. But does the resistant bacterium suffer a cost of resistance (i.e. a reduction in fitness) when the antibiotic is absent? If so, then one strategy to control the spread of resistance would be to suspend the use of a particular antibiotic until resistant genotypes declined to low frequency. Numerous studies have indeed shown that resistant genotypes are less fit than their sensitive counterparts in the absence of antibiotic, indicating a cost of resistance. But there is an important caveat: these studies have put antibiotic resistance genes into naïve bacteria, which have no evolutionary history of association with the resistance genes. An important question, therefore, is whether bacteria can overcome the cost of resistance by evolving adaptations that counteract the harmful side-effects of resistance genes. In fact, several experiments have shown that the cost of antibiotic resistance may be substantially diminished, even eliminated, by evolutionary changes in bacteria over rather short periods of time. As a consequence of this adaptation of bacteria to their resistance genes, it becomes increasingly difficult to eliminate resistant genotypes simply by suspending the use of antibiotics.

Bacteria↗
PubMed2003

The bacterium Xenorhabdus nematophilus depresses nodulation reactions to infection by inhibiting eicosanoid biosynthesis in tobacco hornworms, Manduca sexta.

The bacterium, Xenorhabdus nematophilus, is a virulent insect pathogen. We tested the hypothesis that this bacterium impairs insect cellular immune defense reactions by inhibiting biosynthesis of eicosanoids involved in mediating cellular defense reactions. Fifth instar tobacco hornworms, Manduca sexta, produced melanized nodules in reaction to challenge with living and heat-killed X. nematophilus. However, the nodulation reactions were much attenuated in insects challenged with living bacteria (approximately 20 nodules/larva for living bacteria vs. approximately 80 nodules/larva in insects challenged with heat-killed bacteria). The nodule-inhibiting action of living X. nematophilus was due to a factor that was present in the organic, but not aqueous, fraction of the bacterial cultural medium. The nodule-inhibiting factor in the organic fraction was labile to heat treatments. The immunodepressive influence of the factor in the organic fraction was reversed by treating challenged hornworms with arachidonic acid. The factor also depressed nodulation reactions to challenge with the plant pathogenic bacteria, Pseudomonas putida and Ralstonia solanacearum. These findings indicate that one or more factors from X. nematophilus depress nodulation reactions in tobacco hornworms by inhibiting eicosanoid biosynthesis.

Animals↗