RESUMO
Fungal strains isolated from rocks and lichens collected in the Antarctic ice-free area of the Victoria Land, one of the coldest and driest habitats on earth, were found in two phylogenetically isolated positions within the subclass Dothideomycetidae. They are here reported as new genera and species, Recurvomyces mirabilisgen. nov., sp. nov. and Elasticomyces elasticusgen. nov., sp. nov. The nearest neighbours within the clades were other rock-inhabiting fungi from dry environments, either cold or hot. Plant-associated Mycosphaerella-like species, known as invaders of leathery leaves in semi-arid climates, are also phylogenetically related with the new taxa. The clusters are also related to the halophilic species Hortaea werneckii, as well as to acidophilic fungi. One of the latter, able to grow at pH 0, is Scytalidium acidophilum, which is ascribed here to the newly validated genus Acidomyces. The ecological implications of this finding are discussed.
RESUMO
Fluorescent in situ hybridization (FISH), applied directly on samples taken with adhesive tape, is proposed as method to detect and identify microorganisms from the surfaces of valuable objects without being destructive. Results of tests carried out in laboratory conditions as well on samples taken from deteriorated surfaces of Roman Catacombs showed the feasibility of FISH when applied on adhesive tape. The potential as well as the limits of the technique were also discussed.
Assuntos
Bactérias/isolamento & purificação , Hibridização in Situ Fluorescente/métodos , Adesivos , BiofilmesRESUMO
An easy and fast non-destructive method for sampling from monument and art object surfaces is proposed. The results obtained after sampling in regions of black spots and discoloration using adhesive tape strips showed that the method is useful for monitoring microbial colonization as well as for the identification of biodeteriogens. This technique is easy to apply, inexpensive and reproducible. The presence of fungi or algae on stone surfaces can be checked at an early stage of colonization or after cleaning procedures, without damage to the sampled surface. In addition, it is possible to obtain information on the morphology and taxonomy of microorganisms, and their relationships with the colonized material surfaces.
Assuntos
Adesivos , Arte , Técnicas Microbiológicas/métodos , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Bactérias/ultraestrutura , Biofilmes , Eucariotos/crescimento & desenvolvimento , Eucariotos/isolamento & purificação , Eucariotos/ultraestrutura , Fungos/crescimento & desenvolvimento , Fungos/isolamento & purificação , Fungos/ultraestrutura , Microscopia Eletrônica de Varredura , Microscopia de Fluorescência , Reprodutibilidade dos TestesRESUMO
Intra-specific diversity of Aureobasidium pullulans strains isolated from environmental sources and from stones was studied by assessment of morphological, biochemical and physiological characters as well as random amplified polymorphic DNA (RAPD) using microsatellite or minisatellite DNA primers (GTG)5, (GACA)4, M13. The results showed that both classical and molecular techniques evidenced a phenotypic and genetic diversity of analysed A. pullulans strains. A different behaviour was observed in reference to the growth responses with D-glucosamine, citrate, galactitol and with different salt concentrations and range of growth temperature. Molecular analysis partially confirmed the data obtained with biochemical and physiological tests, additionally showing common fragments in all strains, to be used for a possible application as 'in situ' probes and for a rapid identification of A. pullulans strains.
Assuntos
Ascomicetos/genética , Microbiologia Ambiental , Variação Genética , Sedimentos Geológicos/microbiologia , Técnica de Amplificação ao Acaso de DNA Polimórfico , Ascomicetos/classificação , Ascomicetos/isolamento & purificação , DNA Fúngico/análise , DNA Fúngico/genética , Repetições de Microssatélites/genética , Repetições Minissatélites/genéticaRESUMO
Abstract Phototrophic microbial communities present in the Roman Catacombs were characterized and different species of terrestrial epilithic cyanobacteria were found to occur as dominant organisms. Eucapsis, Leptolyngbya, Scytonema, and Fischerella were the most frequently encountered cyanobacterial taxa, while a few species of green algae and the diatom Diadesmis gallica occurred in minor amounts. Streptomyces strains, a few genera of eubacteria, and to a lesser extent fungi were always present in the same microhabitats and contributed to the deterioration of stone surfaces. The combined use of light and electron microscopy evidenced the structural relationships among rod-shaped or filamentous bacteria and cyanobacterial cells, as well as the presence of polysaccharide capsules and sheaths, and of mineral precipitates on S. julianum filaments. The significance of the intimate association among the microorganisms was discussed in relation to the damage caused by the growth of biological patinas on stone surfaces.http://link.springer-ny.com/link/service/journals/00248/bibs/38n3p244.html
Assuntos
Biofilmes , Microbiologia Ambiental , Arqueologia , Bactérias/genética , Bactérias/isolamento & purificação , Sequência de Bases , Ecossistema , Fungos/genética , Fungos/isolamento & purificação , Histocitoquímica , Hibridização in Situ Fluorescente , Microscopia Confocal , Microscopia Eletrônica , Microscopia de Fluorescência , Sondas de Oligonucleotídeos/genéticaRESUMO
A new species of Pseudotaeniolina, a genus of anamorphic, melanized fungi with meristematic development, is described. The species is compared to morphologically similar taxa among which are Trimmatostroma and Coniosporium. Its novelty is supported by SSU (small subunit) and ITS (internal transcribed spacer) rDNA sequence data.
Assuntos
Fungos/classificação , Melaninas/metabolismo , Ascomicetos/classificação , Ascomicetos/metabolismo , Carbonato de Cálcio , DNA Fúngico/análise , DNA Espaçador Ribossômico/análise , Fungos/genética , Fungos/crescimento & desenvolvimento , Fungos/metabolismo , Itália , Técnicas de Tipagem Micológica , Quartzo , Análise de Sequência de DNA , TemperaturaRESUMO
A Gram-positive, aerobic bacterium with coccoid cells occurring singly, in pairs and in clusters was isolated from the surface of a marble statue. The peptidoglycan contain LL-diaminopimelic acid as diagnostic diamino acid and a single glycine residue as interpeptide bridge (type A3 gamma). The major menaquinone is MK-8(H4). The cellular fatty acid pattern consists of straight chain saturated and monounsaturated components and 10-methyl octadecanoic (tuberculostearic) acid as the only branched chain fatty acid. Phosphatidylinositol, phosphatidylglycerol and diphosphatidylglycerol occur as characteristic polar lipids. The DNA G + C composition is 72 mol%. According to its phylogenetic position and 16S rDNA signature nucleotides, the organism is a member of the family Nocardioidaceae. The combination of chemotaxonomic characteristics is unique within this family and supports the description of a new genus and new species, Marmoricola aurantiacus. The type strain is strain BC 361T (= DSM 12652T).
Assuntos
Actinomycetales/classificação , Carbonato de Cálcio , Escultura , Actinomycetales/química , Actinomycetales/isolamento & purificação , Actinomycetales/fisiologia , Composição de Bases , Meios de Cultura , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Ácidos Graxos/análise , Dados de Sequência Molecular , Fenótipo , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNARESUMO
An investigation was made into the occurrence and biodiversity of Geodermatophilaceae on 78 samples of altered stone surfaces from 24 monuments and natural stones in the Mediterranean basin; it was found that the total microbial counts ranged between 0 and 10(7) cfu g(-1) dry weight. Members of the Geodermatophilaceae family were isolated from 22 of the 78 samples examined, with the incidence of Geodermatophilaceae colonies in the cultivable population ranging from 1% to 100%. The highest percentage was found in six samples of markedly deteriorated stone. Sixty-five strains randomly isolated from the plates were clustered in six different groups by amplified 16S rDNA restriction analysis (ARDRA) using five different restriction enzymes. Twenty-five strains, representing all the ARDRA haplotypes, were characterized further by partial sequencing (350-550 bp) of the 16S rDNA and by analysing 76 morphological, metabolic and physiological properties. The strains were associated with three well-separated clusters of the genera Geodermatophilus, Blastococcus and Modestobacter. On the basis of 16S rDNA sequence and ARDRA analysis, only two strains were found to be related to the two reference strains of Geodermatophilus. All the others could be grouped with Blastococcus aggregatus (19 strains) or the Antarctic species Modestobacter multiseptatus (44 strains), suggesting that it is these two groups, rather than Geodermatophilus, that tend to colonize the stone surfaces, and that Modestobacter-like strains are also found in temperate/Mediterranean climates. From the BOX-polymerase chain reaction (PCR) data, it can be seen that the Modestobacter-like strains, belonging to the most represented ARDRA haplotype (haplotype B, 34 strains), are very polymorphic and that, over a stone surface, there is a wide genetic diversity at the microsite level.