RESUMO
AIMS: To evaluate archaeal diversity in natural and impacted habitats from Rio de Janeiro state, Brazil, a tropical region of South America. METHODS AND RESULTS: 16S rRNA gene was amplified directly by polymerase chain reaction (PCR) from genomic DNA, extracted from Guanabara Bay (GB) water, halomarine sediment (HS), municipal landfill leachate, agricultural soil and wastewater treatment (WT) system. Five archaeal 16S rDNA clone libraries were constructed. A total of 123 clones, within the five libraries analysed, were clustered into 29 operational taxonomic units, related to cultivated (24%) and uncultivated (76%) organisms. Rarefaction analysis showed that the libraries contained different levels of diversity. PCR-denaturing gradient gel electrophoresis (DGGE) of 16S-23S intergenic spacer regions confirmed the presence of a dominant phylotype, revealed by the WT system clone library. CONCLUSIONS: Archaeal communities of impacted environments seem to be confined to specific ecosystems with similar physicochemical properties, while communities from natural environments appear to be widely distributed. The presence of a high number of phylotypes related to uncultivated organisms suggests new archaeal lineages. SIGNIFICANCE AND IMPACT OF THE STUDY: This study reports, for the first time, the analysis of archaeal diversity in tropical environments from Brazil, and adds sequences from this region to the developing database of 16S rRNA clone libraries from environmental samples.
Assuntos
Archaea/classificação , Clima Tropical , Archaea/genética , Archaea/isolamento & purificação , Biodiversidade , Brasil , DNA Arqueal/genética , Ecossistema , Eletroforese em Gel de Poliacrilamida/métodos , Biblioteca Gênica , Filogenia , Reação em Cadeia da Polimerase/métodos , RNA Ribossômico 16S/genética , Microbiologia do Solo , Resíduos , Microbiologia da ÁguaAssuntos
Aminoacil-tRNA Sintetases/metabolismo , Lisina-tRNA Ligase/metabolismo , Aminoacil-RNA de Transferência/metabolismo , Aminoacil-tRNA Sintetases/química , Aminoacil-tRNA Sintetases/classificação , Aminoacil-tRNA Sintetases/genética , Bactérias/classificação , Bactérias/enzimologia , Bactérias/genética , Lisina-tRNA Ligase/química , Lisina-tRNA Ligase/classificação , Lisina-tRNA Ligase/genética , Mathanococcus/classificação , Mathanococcus/enzimologia , Mathanococcus/genética , Filogenia , Especificidade por SubstratoRESUMO
Glycosphingolipids were extracted from hyphae of Fusarium solani and from an unnamed Fusarium species, and were purified by silica and Iatrobead column chromatography. Their structures were determined by compositional analysis, nuclear magnetic resonance spectroscopy, gas chromatography/mass spectrometry and by fast atom bombardment mass spectrometry of the native and peracetylated materials, which defined their sugar, long-chain base and fatty acid compositions. The locations of the double bonds in the bases were established by 2D NMR spectroscopy and by novel mass spectrometric approaches, including collisional activation of the protonated and lithium-cationized glycosphingolipids, and of the sphingadienene-derived fragment ion at m/z 276. From these results we propose that the structures of the glycosphingolipids from F. solani and Fusarium sp. are N-2'-hydroxyoctadecanoyl-1-O-beta-D-glucopyranosyl-9-methyl-4, 8-sphingadienine and N-2'-hydroxyoctadecenoyl-1-O-beta-D-glucopyranosyl-9-methyl-4, 8-sphingadienine, respectively.
