title: Bacterial community composition of anthropogenic biochar and Amazonian anthrosols assessed by 16S rRNA gene 454 pyrosequencing.
abstract: Biochar (BC) is a common minor constituent of soils and is usually derived from the burning of wood materials. In the case of Amazonian dark earth (ADE) soils, the increased amount of this material is believed to be due to anthropogenic action by ancient indigenous populations. In this study, we use 16S rRNA gene pyrosequencing to assess the bacterial diversity observed in the BC found in ADEs as well as in the dark earth itself and the adjacent Acrisol. Samples were taken from two sites, one cultivated with manioc and one with secondary forest cover. Analyses revealed that the community structure found in each sample had unique features. At a coarse phylogenetic resolution, the most abundant phyla in all sequence libraries were Actinobacteria, Acidobacteria, Verrucomicrobia and Proteobacteria that were present in similar relative abundance across all samples. However, the class composition varied between them highlighting the difference between the Acrisol and the remaining samples. This result was also corroborated by the comparison of the OTU composition (at 97 % identity). Also, soil coverage has shown an effect over the community structure observed in all samples. This pattern was found to be significant through unweighted UniFrac as well as P tests. These results indicate that, although the ADEs are found in patches within the Acrisols, the contrasting characteristics found between them led to the development of significantly different communities.
authors.affiliation: Laboratory of Cellular and Molecular Biology, Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, SP, Brazil. rgtaketani@yahoo.com.br
authors.forename: Rodrigo Gouvêa
authors.initials: RG
authors.lastname: Taketani
authors.forename: Amanda Barbosa
authors.initials: AB
authors.lastname: Lima
authors.forename: Ederson
authors.initials: E
authors.lastname: da Conceição Jesus
authors.forename: Wenceslau Geraldes
authors.initials: WG
authors.lastname: Teixeira
authors.forename: James M
authors.initials: JM
authors.lastname: Tiedje
authors.forename: Siu Mui
authors.initials: SM
authors.lastname: Tsai
mesh_terms: D061271:Acidobacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D039903:Actinobacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D015373:Bacterial Typing Techniques; D044822:Biodiversity; D001938:Brazil; D002606:Charcoal; D004269:DNA, Bacterial / Q000235:genetics; D020459:Genes, rRNA; D059013:Microbial Consortia / Q000235:genetics; D020560:Proteobacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D061327:Verrucomicrobia / Q000145:classification / Q000235:genetics / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; C540010:biochar; D002606:Charcoal