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Bacteria
About: Bacteria is a research topic. Over the lifetime, 23676 publications have been published within this topic receiving 715990 citations. The topic is also known as: eubacteria.
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TL;DR: A combination of morphology, salt tolerance, and guanine plus cytosine content supports the establishment of a new genus, Halomonas, in Family II (Vibrionaceae) of part 8, Gram-Negative Facultatively Anaerobic Bacteria, of Bergey's Manual (8th edition).
Abstract: The morphological, biochemical, and physiological characteristics of nine bacterial strains isolated from a solar salt facility located on Bonaire, Netherlands Antilles are described. The bacteria were gram-negative rods which produce white, opaque colonies on solid media. During the log phase of growth, the cultures consisted of single and paired cells with polar flagella predominating. Older cultures characteristically produced highly elongated, flexible rods. All of these strains reduced NO3 to NO2, grew anaerobically in the presence of NO3, and fermented glucose but oxidized sucrose, glycerol, mannose, and cellobiose. All strains were ornithine and lysine decarboxylase positive, catalase positive, and cytochrome oxidase negative. Eight of the nine strains grew in a complex Casamino Acids liquid medium containing from 0 to 32% (wt/vol) solar salt at temperatures from 23 to 37°C; the ninth strain was restricted in its growth to 0 to 20% solar salt. The guanine plus cytosine content of the deoxyribonucleic acid was 61 ± 1 mol%. This combination of morphology, salt tolerance, and guanine plus cytosine content supports the establishment of a new genus, Halomonas, in Family II (Vibrionaceae) of part 8, Gram-Negative Facultatively Anaerobic Bacteria, of Bergey's Manual (8th edition). The type species of this genus is H. elongata, the type strain of which is isolate 1H9 (= ATCC 33173). Strain 1H15 is regarded as belonging to a biovar of H. elongata on the basis of its production of lophotrichous cells and its inability to grow at 37°c in the presence of 32% solar salt.
405 citations
TL;DR: A new genus of fastidiously anaerobic bacteria which produce a homoacetic fermentation is described, which is tentatively placed in the family Propionibacteriaceae.
Abstract: A new genus of fastidiously anaerobic bacteria which produce a homoacetic fermentation is described. Cells are gram-positive, oval-shaped, short rods which are actively motile by means of one or two subterminal flagella. Hydrogen is oxidized, and carbon dioxide is reduced to acetic acid. Organic substrates which are fermented in a mineral medium include fructose, glucose, lactate, glycerate, and formate. Pantothenate is required as a growth factor. The deoxyribonucleic acid base composition of the type species is 39 mol% guanine plus cytosine. The name Acetobacterium is proposed for this new genus, which is tentatively placed in the family Propionibacteriaceae. The type species, Acetobacterium woodii sp. nov., is named in honor of Harland G. Wood. The type strain of A. woodii is WB1 (= ATCC 29683 and DSM 1030).
400 citations
TL;DR: Oils that exhibited high antimicrobial properties and the broadest range of inhibition included cinnamon bark, lemongrass, and Roman chamomile, which showed a high degree of inhibition against both phage types, while 8 oils showed no inhibition against either phage.
Abstract: The purpose of this study was to examine the inhibitory effect of essential oils against a broad spectrum of microorganisms including bacteria, yeast, molds, and two bacteriophage. The inhibitory effects of 45 oils on eight bacteria (four Gram positive and four Gram negative), two fungi, and one yeast were examined using the disk assay method. Phage inhibition was measured by mixing the oils with a phage suspension, incubating the mixture at 4°C for 24 h, then plating on a lawn of indicator bacteria and assaying for plaque production. Of the oils tested, all oils exhibited inhibition over activity relative to controls. However, a number exhibited only weak inhibition against several gram positive bacteria. Gram negative bacteria were generally more resistant than Gram positive bacteria to oil treatment with Pseudomonas aeruginosa being the most resistant bacteria. Only cinnamon bark (Cinnamomum zeylanicum) and tea tree (Melaleuca alternifolia) oils showed an inhibitory effect against all the test...
400 citations
TL;DR: Emerging functional data suggest that asRNAs in bacteria mediate a plethora of effects and are involved in far more processes than were previously anticipated.
Abstract: Summary: A substantial amount of antisense transcription is a hallmark of gene expression in eukaryotes. However, antisense transcription was first demonstrated in bacteria almost 50 years ago. The transcriptomes of bacteria as different as Helicobacter pylori, Bacillus subtilis, Escherichia coli, Synechocystis sp. strain PCC6803, Mycoplasma pneumoniae, Sinorhizobium meliloti, Geobacter sulfurreducens, Vibrio cholerae, Chlamydia trachomatis, Pseudomonas syringae, and Staphylococcus aureus have now been reported to contain antisense RNA (asRNA) transcripts for a high percentage of genes. Bacterial asRNAs share functional similarities with trans-acting regulatory RNAs, but in addition, they use their own distinct mechanisms. Among their confirmed functional roles are transcription termination, codegradation, control of translation, transcriptional interference, and enhanced stability of their respective target transcripts. Here, we review recent publications indicating that asRNAs occur as frequently in simple unicellular bacteria as they do in higher organisms, and we provide a comprehensive overview of the experimentally confirmed characteristics of asRNA actions and intimately linked quantitative aspects. Emerging functional data suggest that asRNAs in bacteria mediate a plethora of effects and are involved in far more processes than were previously anticipated. Thus, the functional impact of asRNAs should be considered when developing new strategies against pathogenic bacteria and when optimizing bacterial strains for biotechnology.
399 citations
TL;DR: Data indicate that SP-A and SP-D are antimicrobial proteins that directly inhibit the proliferation of Gram-negative bacteria in a macrophage- and aggregation-independent manner by increasing the permeability of the microbial cell membrane.
Abstract: The pulmonary collectins, surfactant proteins A (SP-A) and D (SP-D), have been reported to bind lipopolysaccharide (LPS), opsonize microorganisms, and enhance the clearance of lung pathogens. In this study, we examined the effect of SP-A and SP-D on the growth and viability of Gram-negative bacteria. The pulmonary clearance of Escherichia coli K12 was reduced in SP-A–null mice and was increased in SP-D–overexpressing mice, compared with strain-matched wild-type controls. Purified SP-A and SP-D inhibited bacterial synthetic functions of several, but not all, strains of E. coli, Klebsiella pneumoniae, and Enterobacter aerogenes. In general, rough E. coli strains were more susceptible than smooth strains, and collectin-mediated growth inhibition was partially blocked by coincubation with rough LPS vesicles. Although both SP-A and SP-D agglutinated E. coli K12 in a calcium-dependent manner, microbial growth inhibition was independent of bacterial aggregation. At least part of the antimicrobial activity of SP-A and SP-D was localized to their C-terminal domains using truncated recombinant proteins. Incubation of E. coli K12 with SP-A or SP-D increased bacterial permeability. Deletion of the E. coli OmpA gene from a collectin-resistant smooth E. coli strain enhanced SP-A and SP-D–mediated growth inhibition. These data indicate that SP-A and SP-D are antimicrobial proteins that directly inhibit the proliferation of Gram-negative bacteria in a macrophage- and aggregation-independent manner by increasing the permeability of the microbial cell membrane.
397 citations