title: Microbiological functioning, diversity, and structure of bacterial communities in ultramafic soils from a tropical savanna.
abstract: Ultramafic soils are characterized by high levels of metals, and have been studied because of their geochemistry and its relation to their biological component. This study evaluated soil microbiological functioning (SMF), richness, diversity, and structure of bacterial communities from two ultramafic soils and from a non-ultramafic soil in the Brazilian Cerrado, a tropical savanna. SMF was represented according to simultaneous analysis of microbial biomass C (MBC) and activities of the enzymes β-glucosidase, acid phosphomonoesterase and arylsulfatase, linked to the C, P and S cycles. Bacterial community diversity and structure were studied by sequencing of 16S rRNA gene clone libraries. MBC and enzyme activities were not affected by high Ni contents. Changes in SMF were more related to the organic matter content of soils (SOM) than to their available Ni. Phylogeny-based methods detected qualitative and quantitative differences in pairwise comparisons of bacterial community structures of the three sites. However, no correlations between community structure differences and SOM or SMF were detected. We believe this work presents benchmark information on SMF, diversity, and structure of bacterial communities for a unique type of environment within the Cerrado biome.
authors.affiliation: Embrapa Cerrados, P.O. Box 08223, Brasília, DF, 73310-970, Brazil, marco.pessoa@embrapa.br.
authors.forename: Marco
authors.initials: M
authors.lastname: Pessoa-Filho
authors.forename: Cristine Chaves
authors.initials: CC
authors.lastname: Barreto
authors.forename: Fábio Bueno
authors.initials: FB
authors.lastname: dos Reis Junior
authors.forename: Rodrigo Rocha
authors.initials: RR
authors.lastname: Fragoso
authors.forename: Flávio Silva
authors.initials: FS
authors.lastname: Costa
authors.forename: Ieda
authors.initials: I
authors.lastname: de Carvalho Mendes
authors.forename: Leide Rovênia Miranda
authors.initials: LR
authors.lastname: de Andrade
mesh_terms: D001192:Arylsulfatases / Q000032:analysis; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D018533:Biomass; D058448:Biota; D001938:Brazil; D016000:Cluster Analysis; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D065948:Grassland; D008969:Molecular Sequence Data; D010744:Phosphoric Monoester Hydrolases / Q000032:analysis; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D014329:Tropical Climate; D001617:beta-Glucosidase / Q000032:analysis
chemical_list: D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D010744:Phosphoric Monoester Hydrolases; D001192:Arylsulfatases; D001617:beta-Glucosidase