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1.
Isolation and Characterization of Polymeric Galloyl-Ester-Degrading Bacteria from a Tannery Discharge Place 总被引:1,自引:0,他引:1
Franco AR Calheiros CS Pacheco CC De Marco P Manaia CM Castro PM 《Microbial ecology》2005,50(4):550-556
The culturable bacteria colonizing the rhizosphere of plants growing in the area of discharge of a tannery effluent were characterized.
Relative proportions of aerobic, denitrifying, and sulfate-reducing bacteria were determined in the rhizosphere of Typha latifolia, Canna indica, and Phragmites australis. Aerobic bacteria were observed to be the most abundant group in the rhizosphere, and plant type did not seem to influence
the abundance of the bacterial types analyzed. To isolate bacteria able to degrade polyphenols used in the tannery industry,
enrichments were conducted under different conditions. Bacterial cultures were enriched with individual polyphenols (tannins
Tara, Quebracho, or Mimosa) or with an undefined mixture of tannins present in the tannery effluent as carbon source. Cultures
enriched with the effluent or Tara tannin were able to degrade tannic acid. Six bacterial isolates purified from these mixed
cultures were able to use tannic acid as a sole carbon source in axenic culture. On the basis of 16S ribosomal DNA sequence
analysis, these isolates were closely related to organisms belonging to the taxa Serratia, Stenotrophomonas maltophilia, Klebsiella oxytoca, Herbaspirillum chlorophenolicum, and Pseudomonas putida. 相似文献
2.
Ana R. Lopes Anthony S. Danko Célia M. Manaia Olga C. Nunes 《Applied microbiology and biotechnology》2013,97(6):2691-2700
The aims of the present study were to assess the potential of natural attenuation or bioaugmentation to reduce soil molinate contamination in paddy field soils and the impact of these bioremediation strategies on the composition of soil indigenous microbiota. A molinate mineralizing culture (mixed culture DC) was used as inoculum in the bioaugmentation assays. Significantly higher removal of molinate was observed in bioaugmentation than in natural attenuation microcosms (63 and 39 %, respectively) after 42 days of incubation at 22 °C. In the bioaugmentation assays, the impact of Gulosibacter molinativorax ON4T on molinate depletion was observed since the gene encoding the enzyme responsible for the initial molinate breakdown (harboured by that actinobacterium) was only detected in inoculated microcosms. Nevertheless, the exogenous mixed culture DC did not overgrow as the heterotrophic counts of the bioaugmentation microcosms were not significantly different from those of natural attenuation and controls. Moreover, the actinobacterial clone libraries generated from the bioaugmentation microcosms did not include any 16S rRNA gene sequences with significant similarity to that of G. molinativorax ON4T. The multivariate analysis of the 16S rRNA DGGE patterns of the soil microcosm suggested that the activity of mixed culture DC did not affect the soil bacterial community structure since the DGGE patterns of the bioaugmentation microcosms clustered with those of natural attenuation and controls. Although both bioremediation approaches removed molinate without indigenous microbiota perturbation, the results suggested that bioaugmentation with mixed culture DC was more effective to treat soils contaminated with molinate. 相似文献
3.
The diversity of heterotrophic bacterial isolates of three commercial and two homemade composts was studied. The commercial
composts were produced from poultry litter (PC), sewage sludge (SC), municipal solid waste (MC), and homemade composts (thermal
compost [DC] and vermicompost [VC]) from food wastes. The taxonomic and physiological diversity of the heterotrophic culturable
bacteria was assessed using phenotypic and genotypic characterization and the analysis of the partial 16S rRNA gene sequence.
Composts DC and SC presented the higher genotypic diversity, as could be inferred from the number of distinct genotypic patterns
observed, 28 and 21, respectively. Gram-positive bacteria, mainly Firmicutes, were predominant in all the composts. Some organisms related with taxa rarely reported in composts, as Rhodanobacter spathiphylli, Moraxella osloensis, Lysobacter, Corynebacterium, Pigmentiphaga kullae, and new taxa were also isolated. The highest relative proportion of isolates able to degrade starch was found in compost
SC (>70%), to degrade gelatine in compost DC (>70%), to degrade Tween 80 in compost PC (>90%), and to degrade poly-epsilon-caprolactones
in compost DC (>80%). Compost MC presented the lowest relative proportions of isolates able to degrade starch (<25%), gelatine
(<20%), and poly-epsilon-caprolactone (<40%). When compared with the others, the homemade composts presented higher relative
proportions of Gram-positive isolates able to inhibit the target organisms Staphylococcus aureus, Enterococcus
faecalis, Escherichia coli, or Pseudomonas aeruginosa. In compost MC, none of the Gram-positive isolates was able to inhibit those targets. 相似文献
4.
Thirty mesophilic and thermophilic bacteria were isolated from thermobiotically digested sewage sludge in culture medium supplemented with poly-ε-caprolactone (PCL). The ability of each purified isolate to degrade PCL and to produce polymer-degrading extracellular enzymes was assessed. Isolates were characterized based on random amplified polymorphic DNA (RAPD), 16S rDNA sequence-based phylogenetic affiliation and carbohydrate-based nutritional versatility. Mesophilic isolates with ability to degrade PCL were attributed to the genera Acinetobacter, Burkholderia, Pseudomonas, and Staphylococcus. Thermophilic isolates were members of the genus Bacillus. Despite the restricted phylogenetic and genotypic diversity observed for thermophiles, their metabolic versatility and wide range of growth temperatures suggest an important activity of these organisms during the whole composting process. 相似文献
5.
A novel pathway for mineralization of the thiocarbamate herbicide molinate by a defined bacterial mixed culture 总被引:1,自引:0,他引:1
Barreiros L Nogales B Manaia CM Ferreira AC Pieper DH Reis MA Nunes OC 《Environmental microbiology》2003,5(10):944-953
A bacterial mixed culture able to mineralize molinate was established, through enrichment, using mineral medium with molinate as the only carbon, nitrogen and energy source. The combination of five cultivable isolates, purified from the enrichment culture, permitted the reconstitution of a degrading consortium. Both enrichment and defined cultures were able to mineralize molinate without accumulation of degradation products by the end of the growth. Among the five isolates constituting the defined mixed culture, an actinomycete, strain ON4, was essential for biodegradation, being involved in the cleavage of the thioester bond of molinate, the initial step of the degradation pathway. Isolate ON4 was able to grow on molinate at concentrations below 2 mM, with the accumulation of ethanethiol and diethyl disulphide. These sulphur compounds were toxic to strain ON4 when accumulating at higher concentrations. However, this inhibitory effect was avoided by the presence of other members of the mixed culture, out of which isolates ON1 and ON2 were observed to consume ethanethiol and diethyl disulphide. In this way, interactions among defined mixed culture members involve metabolic and detoxifying association. 相似文献
6.
Lmo2 and GATA-3 associated expression in intraembryonic hemogenic sites 总被引:11,自引:0,他引:11
7.
Nunes OC Manaia CM Da Costa MS Santos H 《Applied and environmental microbiology》1995,61(6):2351-2357
(sup13)C nuclear magnetic resonance spectroscopy and (sup1)H nuclear magnetic resonance spectroscopy were used to identify and quantify the organic solutes of several strains of halophilic or halotolerant thermophilic bacteria. Two strains of Rhodothermus marinus and four strains of "Thermus thermophilus" grown in complex medium containing NaCl were examined. 2-O-Mannosylglycerate was a major compatible solute in all strains: the Thermus strains accumulated the (beta)-anomer only, whereas both anomers were found in R. marinus. 2-O-(beta)-mannosylglycerate and 2-O-(alpha)-mannosylglycerate were the major compatible solutes in R. marinus. The former was the predominant solute in cells grown in 2.0 and 4.0% NaCl-containing medium, while the latter was the predominant compatible solute at higher salinities. Glutamate, trehalose, and glucose were also present as minor components. The intracellular K(sup+) concentration, as determined by (sup39)K nuclear magnetic resonance spectroscopy, in R. marinus increased with salinity and was sufficient to balance the negative charges of the mannosylglycerate. In addition to 2-O-(beta)-mannosylglycerate, trehalose was a major compatible solute of "T. thermophilus." 2-O-(beta)-Mannosylglycerate was the main solute in medium containing 1.0 or 2.0% NaCl, while trehalose predominated in cells grown in medium supplemented with 3.0 or 4.0% NaCl. Glycine betaine, in lower concentrations, was also detected in two "T. thermophilus" strains. This is the first report of mannosylglycerate as a compatible solute in bacteria. 相似文献
8.
Municipal wastewater treatment plants are recognized reservoirs of antibiotic-resistant bacteria. Three municipal wastewater
treatment plants differing on the dimensions and bio-treatment processes were compared for the loads of amoxicillin-, tetracycline-,
and ciprofloxacin-resistant heterotrophic bacteria, enterobacteria, and enterococci in the raw inflow and in the treated effluents.
The sewage received by each plant, in average, corresponded to 85,000 inhabitant equivalents (IE), including pretreated industrial
effluents (≤30%) in plant activated sludge, 105,000 IE, including pretreated hospital effluents (≤15%) in plant trickling
filter, and 2,000 IE, exclusively of domestic sewage, in plant submerged aerated filter. The presence of pretreated industrial
effluents or of pretreated hospital sewage in the raw inflow did not imply significantly higher densities (per milliliter
or per IE) of antibiotic-resistant bacteria in the raw wastewater. Longer hydraulic residence periods (24 h) corresponded
to higher bacterial removal rates than shorter periods (12 and 9 h), although such efficiency did not imply significant average
decreases in the antibiotic resistance prevalence of the treated effluent. The bacterial loads in the treated effluent could
be ranked according to the treatment efficiency, suggesting that the characteristics of the raw inflow may have less relevance
on the quality of the treated wastewater than other aspects, such as the inflow volume, the type of biological treatment,
or the hydraulic residence time. 相似文献
9.
Diversity and antibiotic resistance patterns of Sphingomonadaceae isolates from drinking water 总被引:1,自引:0,他引:1
Sphingomonadaceae (n = 86) were isolated from a drinking water treatment plant (n = 6), tap water (n = 55), cup fillers for dental chairs (n = 21), and a water demineralization filter (n = 4). The bacterial isolates were identified based on analysis of the 16S rRNA gene sequence, and intraspecies variation was assessed on the basis of atpD gene sequence analysis. The isolates were identified as members of the genera Sphingomonas (n = 27), Sphingobium (n = 28), Novosphingobium (n = 12), Sphingopyxis (n = 7), and Blastomonas (n = 12). The patterns of susceptibility to five classes of antibiotics were analyzed and compared for the different sites of isolation and taxonomic groups. Colistin resistance was observed to be intrinsic (92%). The highest antibiotic resistance prevalence values were observed in members of the genera Sphingomonas and Sphingobium and for beta-lactams, ciprofloxacin, and cotrimoxazole. In tap water and in water from dental chairs, antibiotic resistance was more prevalent than in the other samples, mainly due to the predominance of isolates of the genera Sphingomonas and Sphingobium. These two genera presented distinct patterns of association with antibiotic resistance, suggesting different paths of resistance development. Antibiotic resistance patterns were often related to the species rather than to the site or strain, suggesting the importance of vertical resistance transmission in these bacteria. This is the first study demonstrating that members of the family Sphingomonadaceae are potential reservoirs of antibiotic resistance in drinking water. 相似文献
10.