Browsing by Author "Lopes, Ana R."
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- Bacillus purgationiresistans sp. nov., isolated from a drinking-water treatment plantPublication . Vaz-Moreira, Ivone; Figueira, Vânia; Lopes, Ana R.; Lobo-da-Cunha, Alexandre; Sproer, Cathrin; Schumann, Peter; Nunes, Olga C.; Manaia, Célia M.A Gram-positive, aerobic, non-motile, endospore-forming rod, designated DS22T, was isolated from a drinking-water treatment plant. Cells were catalase- and oxidase-positive. Growth occurred at 15–37 6C, at pH 7–10 and with ,8% (w/v) NaCl (optimum growth: 30 6C, pH 7–8 and 1–3% NaCl). The major respiratory quinone was menaquinone 7, the G+C content of the genomic DNA was 36.5 mol% and the cell wall contained meso-diaminopimelic acid. On the basis of 16S rRNA gene sequence analysis, strain DS22T was a member of the genus Bacillus. Its closest phylogenetic neighbours were Bacillus horneckiae NRRL B-59162T (98.5% 16S rRNA gene sequence similarity), Bacillus oceanisediminis H2T (97.9 %), Bacillus infantis SMC 4352-1T (97.4 %), Bacillus firmus IAM 12464T (96.8 %) and Bacillus muralis LMG 20238T (96.8 %). DNA–DNA hybridization, and biochemical and physiological characterization allowed the differentiation of strain DS22T from its closest phylogenetic neighbours. The data supports the proposal of a novel species, Bacillus purgationiresistans sp. nov.; the type strain is DS22T (5DSM 23494T5NRRL B-59432T5LMG 25783T).
- Bacterial community variations in an alfalfa-rice rotation system revealed by 16S rRNA gene 454-pyrosequencingPublication . Lopes, Ana R.; Manaia, Célia M.; Nunes, Olga C.Crop rotation is a practice harmonized with the sustainable rice production. Nevertheless, the implications of this empirical practice are not well characterized, mainly in relation to the bacterial community composition and structure. In this study, the bacterial communities of two adjacent paddy fields in the 3rd and 4th year of the crop rotation cycle and of a nonseeded subplot were characterized before rice seeding and after harvesting, using 454-pyrosequencing of the 16S rRNA gene. Although the phyla Acidobacteria, Proteobacteria, Chloroflexi, Actinobacteria and Bacteroidetes predominated in all the samples, there were variations in relative abundance of these groups. Samples from the 3rd and 4th years of the crop rotation differed on the higher abundance of groups of presumable aerobic bacteria and of presumable anaerobic and acidobacterial groups, respectively. Members of the phylum Nitrospira were more abundant after rice harvest than in the previously sampled period. Rice cropping was positively correlated with the abundance of members of the orders Acidobacteriales and Solibacterales' and negatively with lineages such as Chloroflexi Ellin6529'. Studies like this contribute to understand variations occurring in the microbial communities in soils under sustainable rice production, based on real-world data.
- Candidimonas nitroreducens gen. nov., sp. nov. and Candidimonas humi sp. nov., isolated from sewage sludge compostPublication . Vaz-Moreira, Ivone; Figueira, Vânia; Lopes, Ana R.; De Brandt, Evie; Vandamme, Peter; Nunes, Olga C.; Manaia, Célia M.Two bacterial strains (SC-089T and SC-092T) isolated from sewage sludge compost were characterized by using a polyphasic approach. The isolates were Gram-negative short rods, catalase- and oxidase-positive, and showed good growth at 30 °C, at pH 7 and with 1 % (w/v) NaCl. Ubiquinone 8 was the major respiratory quinone, and phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol were amongst the major polar lipids. On the basis of 16S rRNA gene sequence analysis, the strains were observed to be members of the family Alcaligenaceae, but could not be identified as members of any validly described genus. The low levels of 16S rRNA gene sequence similarity to other recognized taxa, together with comparative analysis of phenotypic traits and chemotaxonomic markers, supported the proposal of a new genus within the family Alcaligenaceae, for which the name Candidimonas gen. nov. is proposed. Strains SC-089T and SC-092T, which shared 99.1 % 16S rRNA gene sequence similarity, could be differentiated at the phenotypic level, and DNA–DNA hybridization results supported their identification as representing distinct species. The names proposed for these novel species are Candidimonas nitroreducens sp. nov. (type strain, SC-089T = LMG 24812T = CCUG 55806T) and Candidimonas humi sp. nov. (type strain, SC-092T = LMG 24813T = CCUG 55807T).
- Comparative study of the microbial diversity of bulk paddy soil of two rice fields subjected to organic and conventional farmingPublication . Lopes, Ana R.; Faria, Cátia; Prieto-Fernández, Ángeles; Trasar-Cepeda, Carmen; Manaia, Célia M.; Nunes, Olga C.Two adjacent paddies of an experimental rice field, subjected to organic and conventional farming, were characterized aiming the comparative assessment of microbiological variations occurring in the bulk paddy soil over the rice cycle. This study comprehended the simultaneous characterization of general physicochemical soil properties [total carbon and nitrogen, pH (H2O and KCl), C:N ratio and water content], biochemical properties [enzymatic activities and Community Level Physiological Profiles (CLPP)], the estimation of cultivable organisms (enumeration of fast growing heterotrophic bacteria, actinomycetes and fungi) and the assessment of bacterial diversity using a culture-independent method (PCR-DGGE fingerprinting). The linkage of the parameters measured was analysed by canonical correspondence analysis (CCA). CCA ordination plots of the CLPP showed a similar pattern of microbial functional activity in both agronomic management systems, except in June. Enzymatic activity, water content and fungi counts were the main factors affecting the observed CLPP time variation. Such a variation was not expressed by the Shannon and evenness indices, which did not evidence significant differences in the bacterial and functional diversity between or within farming type over the analysed period. The cluster and CCA analyses of the DGGE profiles allowed the distinction of the bacterial communities of both paddies, with temporal variations being observed in the organically managed field but not in the conventional paddy. Enzymatic activity, pH and molinate content were the factors which most contributed to the observed variations. Altogether these results underline the functional redundancy of the rice paddy soil and evidence the temporal variations on the metabolic activity of soil, irrespective of farming type.
- Microbacterium invictum sp. nov., isolated from homemade compostPublication . Vaz-Moreira, Ivone; Lopes, Ana R.; Faria, Cátia; Sproer, Cathrin; Schumann, Peter; Nunes, Olga C; Manaia, Célia M.Strain DC-200T was isolated from homemade compost produced from kitchen refuse and characterized using a polyphasic approach. The isolate was a Gram-positive motile short rod, facultatively aerobic, catalase-positive and oxidase-negative, and was able to grow at 10–37 6C, pH 6.0–9.5 and with up to 5% of NaCl. The peptidoglycan was of the type B1 alpha and the muramic acid residues were glycolylated. The major fatty acids were anteiso-C15 : 0 and anteiso- C17 : 0. The predominant respiratory menaquinones were MK-11 and MK-12. The G+C content of the genomic DNA was 70 mol%. Based on the analysis of the 16S rRNA gene sequence, the closest phylogenetic neighbours of strain DC-200T were Microbacterium lacus A5E-52T (98.7 %) and Microbacterium aoyamense KV-492T (98.2 %). The phenetic characterization of the isolate supports its inclusion within the genus Microbacterium; however, its distinctive phenotypic features and the results from the 16S rRNA gene sequence analysis and the DNA–DNA hybridization study suggest that the isolate represents a novel species. The name Microbacterium invictum sp. nov. is proposed. The type strain is DC-200T (5DSM 19600T5LMG 24557T).
- Microbacterium luticocti sp. nov., isolated from sewage sludge compostPublication . Vaz-Moreira, Ivone; Lopes, Ana R.; Falsen, Enevold; Schumann, Peter; Nunes, Olga C.; Manaia, Célia M.Strain SC-087BT, isolated from sewage sludge compost during a study of bacterial diversity in composts, was characterized. The isolate was a Gram-positive, short rod that was motile, catalase- and oxidase-negative and able to grow at 27–45 6C, pH 5.5–9.7 and in up to 10% NaCl. The peptidoglycan was of the B2b type, containing the characteristic amino acids ornithine, homoserine and hydroxyglutamic acid. The muramic acid residues of the peptidoglycan were partially glycolylated. The major cell-wall sugar was mannose; traces of xylose were also detected. The predominant fatty acids, comprising more than 70% of the total, were anteiso-C17 : 0 and anteiso-C15 : 0, the major respiratory quinone was menaquinone-12 (MK-12) and the G+C content of the genomic DNA was 72 mol%. Based on analysis of the 16S rRNA gene sequence, the closest phylogenetic neighbours of strain SC-087BT were members of the family Microbacteriaceae, showing sequence similarity values of around 96% with members of the species Microbacterium barkeri (96.0 %), Microbacterium gubbeenense (95.6 %) and Microbacterium indicum (95.7 %). The chemotaxonomic and phenotypic traits analysed supported the inclusion of this strain within the genus Microbacterium and the proposal of a novel species. The name Microbacterium luticocti sp. nov. is proposed and the type strain is SC-087BT (5DSM 19459T5CCUG 54537T).
- Microbial degradation of the herbicide molinate by defined cultures and in the environmentPublication . Nunes, Olga C.; Lopes, Ana R.; Manaia, Célia M.Molinate is a thiocarbamate herbicide used worldwide in rice crop protection. As with other pesticides, molinate is a recognized environmental pollutant, detected in soils, irrigation water, or rivers and bio-accumulated by some wildlife forms. For this reason, and in spite of its low toxicity to humans, environmental protection measures, which include reduction of use and/or remediation processes, are recommended. Due to its physic-chemical properties, molinate can easily disperse and react in the environment, originating diverse transformation products, some with increased toxicity. In spite of being a xenobiotic compound, molinate can also suffer microbial transformation by bacteria or fungi, sometimes serving as nutrient and energy source. In an attempt to isolate microorganisms to be used in the bioremediation of molinate-contaminated sites, a mixed culture, dominated by the actinobacterium Gulosibacter molinativorax ON4(T), was recovered from the runoff of a molinate-producing plant. Beyond a promising tool to decontaminate molinate-polluted sites, this culture also brought interesting insights into the biology of the degradation of this herbicide. In this review, an overview of the distribution and properties of molinate as environmental contaminant, the capability of microorganisms to transform this herbicide, and some reflections about possible bioremediation approaches are made.
- Relationships among bulk soil physicochemical, biochemical, and microbiological parameters in an organic alfalfa-rice rotation systemPublication . Lopes, Ana R.; Bello, Diana; Prieto-Fernández, Ángeles; Trasar-Cepeda, Carmen; Manaia, Célia M.; Nunes, Olga C.The microbial communities of bulk soil of rice paddy fields under an ancient organic agriculture regimen, consisting on an alfalfa-rice rotation system, were characterized. The drained soil of two adjacent paddies at different stages of the rotation was compared before rice seeding and after harvesting. The relationships among the soil microbial, physicochemical, and biochemical parameters were investigated using multivariate analyses. In the first year of rice cropping, aerobic cultivable heterotrophic populations correlated with lineages of presumably aerobic bacteria (e.g., Sphingobacteriales, Sphingomonadales). In the second year of rice cropping, the total C content correlated with presumable anaerobic bacteria (e.g., Anaerolineae). Independently of the year of rice cropping, before rice seeding, proteolytic activity correlated positively with the cultivable aerobic heterotrophic and ammonifier populations, the soil catabolic profile and with presumable aerobes (e.g., Sphingobacteriales, Rhizobiales) and anaerobes (e.g., Bacteroidales, Anaerolineae). After harvesting, strongest correlations were observed between cultivable diazotrophic populations and bacterial groups described as comprising N-2 fixing members (e.g., Chloroflexi-Ellin6529, Betaproteobacteria, Alphaproteobacteria). It was demonstrated that chemical parameters and microbial functions were correlated with variations on the total bacterial community composition and structure occurring during rice cropping. A better understanding of these correlations and of their implications on soil productivity may be valid contributors for sustainable agriculture practices, based on ancient processes.
- Shinella fusca sp. nov., isolated from domestic waste compostPublication . Vaz-Moreira, Ivone; Faria, Cátia; Lopes, Ana R.; Svensson, Liselott A.; Moore, Edward R. B.; Nunes, Olga C.; Manaia, Célia M.A bacterium, designated strain DC-196T, isolated from kitchen refuse compost was analysed by using a polyphasic approach. Strain DC-196T was characterized as a Gram-negative short rod that was catalase- and oxidase-positive, and able to grow at 10–40 6C, pH 6–9 and in NaCl concentrations as high as 3%. Chemotaxonomically, C18 : 1 was observed to be the predominant cellular fatty acid and ubiquinone 10 (Q10) was the predominant respiratory quinone. The G+C content of the genomic DNA was determined to be 66 mol%. On the basis of the genotypic, phenotypic and chemotaxonomic characteristics, strain DC-196T was assigned to the genus Shinella, although with distinctive features. At the time of writing, 16S rRNA gene sequence similarities of 97.6–96.8% and the low DNA–DNA hybridization values of 38.2–32.2% with the type strains of the three recognized Shinella species confirmed that strain DC-196T represents a novel species of the genus, for which the name Shinella fusca sp. nov. is proposed (type strain DC-196T5CCUG 55808T5LMG 24714T).
- Sphingobium vermicomposti sp. nov., isolated from vermicompostPublication . Vaz-Moreira, Ivone; Faria, Cátia; Lopes, Ana R.; Svensson, Liselott; Falsen, Enevold; Moore, Edward R. B.; Ferreira, António C. Silva; Nunes, Olga C.; Manaia, Célia M.Strain VC-230T was isolated from homemade vermicompost produced from kitchen waste. The isolate was a Gram-negative-staining, catalase- and oxidase-positive, motile rod-shaped bacterium able to grow at 15–37 6C and pH 6–8. On the basis of 16S rRNA gene sequence analysis, strain VC-230T was determined to belong to the family Sphingomonadaceae by its clustering with type strains of the genus Sphingobium, with Sphingobium chlorophenolicum ATCC 33790T (97.7 %) and Sphingobium herbicidovorans DSM 11019T (97.4 %) as its closest neighbours. The polar lipid pattern, the presence of spermidine and ubiquinone 10, the predominance of the cellular fatty acids C18 : 1v7c/9t/12t, C16 : 1v7c and C16 : 0 and the G+C content of the genomic DNA supported the affiliation of this organism to the genus Sphingobium. The phylogenetic, chemotaxonomic, phenotypic and DNA–DNA hybridization analyses verify that strain VC-230T represents a novel species, for which the name Sphingobium vermicomposti sp. nov. is proposed. The type strain is VC-230T (5CCUG 55809T 5DSM 21299T).