Metabolic and genetic diversity of mesophilic and thermophilic bacteria isolated from composted municipal sludge on poly-epsilon-caprolactones.

Departamento de Zoologia and Centro de Neurociências e Biologia Celular, Universidade de Coimbra, 3004-517 Coimbra, Portugal.
Current Microbiology (Impact Factor: 1.52). 01/2005; 49(6):407-14. DOI: 10.1007/s00284-004-4353-0
Source: PubMed

ABSTRACT Thirty mesophilic and thermophilic bacteria were isolated from thermobiotically digested sewage sludge in culture medium supplemented with poly-epsilon-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.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: AIMS: The aim of our research was to select, identify and characterize an isolate of lactic acid bacteria to be considered as a vaginal probiotic. METHODS AND RESULTS: Thirty-five isolates of Pediococcus spp. showed bacteriocinogenic activity against Listeria monocytogenes and the ability to survive in simulated vaginal fluid at pH 4.2. One isolate of Pediococcus spp. was selected and characterized to evaluate its safety before use as vaginal probiotic. Pediococcus pentosaceus SB83 did not show the presence of virulence factors such as the production of gelatinase, lipase and DNase, hemolytic activity, nor the presence of virulence genes (genes esp, agg, gelE, efaAfm, efaAfs, cylA, cylB and cylM). Pediococcus pentosaceus SB83 was considered sensitive to cloramphenicol, gentamicin, streptomycin, kanamycin, erythromycin, and ampicillin. This strain was considered resistant to tetracycline and vancomycin. Pediococcus pentosaceus SB83 was a biofilm-producer at different pH values (4.2, 5.5 and 6.5) in simulated vaginal fluid and in De Man, Rogosa and Sharpe medium. CONCLUSIONS: The in vitro results provide a basis for the use of P. pentosaceus SB83 as a vaginal probiotic, to prevent colonization by L. monocytogenes in pregnant women. SIGNIFICANCE AND IMPACT OF STUDY: The application of vaginal probiotics could have the potential for preventing vaginal infections and consequently reduce abortion and neonatal infections. This article is protected by copyright. All rights reserved.
    Journal of Applied Microbiology 04/2013; · 2.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Plant growth promoting bacteria (PGPR) may help reducing the toxicity of heavy metals to plants in polluted environments. In this work the effects of inoculating metal resistant and plant growth promoting bacterial strains on the growth of Helianthus annuus grown in Zn and Cd spiked soils were assessed. The PGPR strains Ralstonia eutropha (B1) and Chrysiobacterium humi (B2) reduced losses of weight in metal exposed plants and induced changes in metal bioaccumulation and bioconcentration - with strain B2 decreasing up to 67% Zn accumulation and by 20% Zn bioconcentration factor (BCF) in the shoots, up to 64% Zn uptake and 38% Zn BCF in the roots, and up to 27% Cd uptake and 27% Cd BCF in plant roots. The impact of inoculation on the bacterial communities in the rhizosphere of the plant was also assessed. Bacterial community diversity decreased with increasing levels of metal contamination in the soil, but in rhizosphere soil of plants inoculated with the PGPR strains, a higher bacterial diversity was kept throughout the experimental period. Inoculation of sunflower, particularly with C. humi (B2), appears to be an effective way of enhancing the short term stabilization potential of the plant in metal contaminated land, lowering losses in plant biomass and decreasing aboveground tissue contamination.
    Chemosphere 04/2013; · 3.14 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Application of the plant associated bacterium Bacillus amyloliquefaciens FZB42 on lettuce (Lactuca sativa) confirmed its capability to promote plant growth and health by reducing disease severity (DS) caused by the phytopathogenic fungus Rhizoctonia solani. Therefore this strain is commercially applied as an eco-friendly plant protective agent. It is able to produce cyclic lipopeptides (CLP) and polyketides featuring antifungal and antibacterial properties. Production of these secondary metabolites led to the question of a possible impact of strain FZB42 on the composition of microbial rhizosphere communities after its application. Rating of DS and lettuce growth during a field trial confirmed the positive impact of strain FZB42 on the health of the host plant. To verify B. amyloliquefaciens as an environmentally compatible plant protective agent, its effect on the indigenous rhizosphere community was analyzed by metagenome sequencing. Rhizosphere microbial communities of lettuce treated with B. amyloliquefaciens FZB42 and non-treated plants were profiled by high-throughput metagenome sequencing of whole community DNA. Fragment recruitments of metagenome sequence reads on the genome sequence of B. amyloliquefaciens FZB42 proved the presence of the strain in the rhizosphere over 5 weeks of the field trial. Comparison of taxonomic community profiles only revealed marginal changes after application of strain FZB42. The orders Burkholderiales, Actinomycetales and Rhizobiales were most abundant in all samples. Depending on plant age a general shift within the composition of the microbial communities that was independent of the application of strain FZB42 was observed. In addition to the taxonomic profiling, functional analysis of annotated sequences revealed no major differences between samples regarding application of the inoculant strain.
    Frontiers in microbiology. 01/2014; 5:252.

Full-text (2 Sources)

Available from
May 27, 2014