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Mikrobiologiia 2009Phosphobacteria are able to enhance phosphorus availability in soil and improve crop yields. To develop such biofertilizers, 14 predominant phosphobacteria were isolated...
Phosphobacteria are able to enhance phosphorus availability in soil and improve crop yields. To develop such biofertilizers, 14 predominant phosphobacteria were isolated from eutrophic aquatic ecosystems. Molecular identification and phylogenetic analysis revealed three groups among the nine isolates of inorganic phosphate-solubilizing bacteria (IPSB): IPSB1 and IPSB2 belonged to the actinobacteria and flavobacteria, respectively, and the other seven belonged to the gamma-proteobacteria. Among five isolates of organic phosphorus-mineralizing bacteria (OPMB), two groups were present: OPMB1 and OPMB3 belonged to the beta-proteobacteria, while the other three belonged to the gamma-proteobacteria. The IPSB isolates released 62.8-66.7 mg P 1(-1) from tricalcium phosphate under shaking conditions, and 26.8 to 43.7 mg P 1(-1) under static conditions; the OPMB strains released 23.5-30.2 mg P 1(-1) from lecithin under shaking conditions, and 16.7-27.6 mg P 1(-1) under static conditions. To the best of our knowledge, this is the first report indicating that IPSBI (designated Aureobacterium resistents) as a tricalcium phosphate-solubilizing bacterium and OPMB1 and OPMB3 (designated Acidovorax temperans and Achromobacter xylosoxidans, respectively) are lecithin-mineralizing bacteria. This investigation demonstrated that a eutrophic aquatic ecosystem is a selective source of phosphobacteria and the screened phosphobacteria are a potential alternative to the development of biofertilizers.
Topics: Actinobacteria; Actinomycetales; Alcaligenaceae; China; Comamonadaceae; Fertilizers; Flavobacteriaceae; Geologic Sediments; Phosphates; Phosphorus; Phylogeny; Proteobacteria; Water Microbiology
PubMed: 20170019
DOI: No ID Found -
Antonie Van Leeuwenhoek May 2009Extracellular DNA can play a structural role in the microbial environment. Here evidence is presented that an environmental isolate of Acidovorax temperans utilises...
Extracellular DNA can play a structural role in the microbial environment. Here evidence is presented that an environmental isolate of Acidovorax temperans utilises extracellular DNA for intercellular and cell-surface attachment and that Type IV pili and electrostatic interactions play a role in this interaction. Preliminary attempts to isolate and purify extracellular polysaccharides from A. temperans strain CB2 yielded significant amounts of DNA raising the question of whether this molecule was present as a structural component in the extracellular matrix. The role of DNA in attachment was indicated by experiments in which the addition of DNase to liquid medium inhibited the attachment of Acidovorax to glass wool. A Tn5 insertional mutant, lacking Type IV pili, was unable to initiate attachment. Addition of DNase caused rapid detachment of bound cells, but no detachment occurred when proteinase, RNase or inactivated DNase were used. Addition of MgCl(2) also caused significant detachment, supporting the possible mechanistic role of electrostatic interactions in the attachment process. Although attachment was apparent in early to mid-log phase growth, surprisingly DNA was not detected in the culture supernatant until late stationary phase and coincided with an appreciable loss of cell viability. This suggests that during log-phase growth attachment is mediated by eDNA that is released in low quantities and/or is highly localised within the extracellular matrix and also that stationary phase DNA release through widespread cell lysis may be a separate and unrelated event.
Topics: Bacterial Adhesion; Comamonadaceae; DNA Transposable Elements; DNA, Bacterial; Deoxyribonucleases; Fimbriae, Bacterial; Gene Deletion; Glass; Magnesium Chloride; Mutagenesis, Insertional
PubMed: 19263234
DOI: 10.1007/s10482-009-9320-0 -
Systematic and Applied Microbiology Oct 2000For the purpose of denitrification in small drinking water plants, a bacterial mixed population was isolated from a packed bed column bioreactor with...
For the purpose of denitrification in small drinking water plants, a bacterial mixed population was isolated from a packed bed column bioreactor with poly-3-hydroxybutyrate-co-3-hydroxyvalerate (P(HB-co-HV)) as a substrate for the denitrification of ground water (10 degrees C). Isolates 2nIII from the mixed culture, with the ability to denitrify and metabolize P(HB-co-HV), were used as starter cultures for the elimination of nitrate in ground water. The strains were characterized by diverse techniques. Classical phenotypic studies lead to rRNA group III of the genus Pseudomonas. Results obtained by molecular techniques demonstrated that the 2nIII strains are members of the Comamonadaceae and shows similarities to the genus Acidovorax. However, an integration of the 2nIII isolates within one of the known Acidovorax species is not possible for the moment. The 2nIII starter cultures clustered close to Av. temperans according to their whole cell proteins and fatty acids, whereas in DNA/DNA hybridization no significant DNA binding (< 25%) was found. In contrast a significant but low degree of DNA/DNA hybridization was found between the 2nIII strains and Av. facilis and Av. delafieldii. Our polyphasic results lead to the conclusion that the 2nIII strains may constitute a separate Acicdovorax species.
Topics: Bacterial Typing Techniques; Base Composition; Betaproteobacteria; Biodegradation, Environmental; Diabetic Ketoacidosis; Environmental Microbiology; Fatty Acids; Gram-Negative Aerobic Rods and Cocci; Nitrates; Nucleic Acid Hybridization; Polyesters
PubMed: 11108015
DOI: 10.1016/S0723-2020(00)80066-1 -
FEMS Microbiology Letters Jun 1992Ribosomal rRNA gene fragments (rDNA) encompassing the 16S rDNA, the 16S-23S rDNA spacer region and part of the 23S rDNA of 95 strains belonging to 13 well-described taxa... (Comparative Study)
Comparative Study
Ribosomal rRNA gene fragments (rDNA) encompassing the 16S rDNA, the 16S-23S rDNA spacer region and part of the 23S rDNA of 95 strains belonging to 13 well-described taxa of the eubacterial family Comamonadaceae (beta subclass of the Proteobacteria or rRNA superfamily III) were enzymatically amplified using conserved primers. The fragments of approximately 2400 base pairs were subjected to restriction analysis. Restriction fragment length patterns obtained with HinfI enabled us to distinguish 9 of the 13 taxa studied. Restriction with CfoI was necessary to differentiate Acidovorax delafieldii from A. temperans and Hydrogenophaga flava from H. pseudoflava. The results indicate that amplified rDNA restriction analysis is a simple and reliable tool for the identification of bacterial species.
Topics: Base Sequence; DNA Restriction Enzymes; DNA, Bacterial; DNA, Ribosomal; Gram-Negative Aerobic Bacteria; Molecular Sequence Data; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length
PubMed: 1354195
DOI: 10.1111/j.1574-6968.1992.tb05102.x -
International Journal of Systematic... Oct 1990Pseudomonas facilis and Pseudomonas delafieldii are inappropriately assigned to the genus Pseudomonas. They belong to the acidovorans rRNA complex in rRNA superfamily...
Acidovorax, a new genus for Pseudomonas facilis, Pseudomonas delafieldii, E. Falsen (EF) group 13, EF group 16, and several clinical isolates, with the species Acidovorax facilis comb. nov., Acidovorax delafieldii comb. nov., and Acidovorax temperans sp. nov.
Pseudomonas facilis and Pseudomonas delafieldii are inappropriately assigned to the genus Pseudomonas. They belong to the acidovorans rRNA complex in rRNA superfamily III (i.e., the beta subclass of the Proteobacteria). The taxonomic relationships of both of these species, two groups of clinical isolates (E. Falsen [EF] group 13 and EF group 16), and several unidentified or presently misnamed strains were examined by using DNA:rRNA hybridization, numerical analyses of biochemical and auxanographic features and of fatty acid patterns, polyacrylamide gel electrophoresis of cellular proteins, and DNA:DNA hybridization. These organisms form a separate group within the acidovorans rRNA complex, and we propose to transfer them to a new genus, Acidovorax. We describe the following three species in this genus: the type species, Acidovorax facilis (formerly Pseudomonas facilis), with type strain LMG 2193 (= CCUG 2113 = ATCC 11228); Acidovorax delafieldii (for the former Pseudomonas delafieldii and most of the EF group 13 strains), with type strain LMG 5943 (= CCUG 1779 = ATCC 17505); and Acidovorax temperans (for several former Pseudomonas and Alcaligenes strains and most of the EF group 16 strains), with type strain CCUG 11779 (= LMG 7169).
Topics: Base Composition; Base Sequence; Chromatography, Gas; Cluster Analysis; DNA, Bacterial; Electrophoresis; Fatty Acids; Nucleic Acid Hybridization; Phenotype; Pseudomonas; Terminology as Topic
PubMed: 2275854
DOI: 10.1099/00207713-40-4-384