Bacterial community characterization and biogeochemistry of sediments from a tropical upwelling system (Cabo Frio, Southeastern Brazil)

• Type: Article in International Scientific Journal
• Date: 2016

Authors

Castelo Branco, R (Author) Other; Barreiro, A (Author) Other; Silva, FS (Author) Other; Carvalhal Gomes, SBV (Author) Other; Fontana, LF (Author) Other; Mendonca Filho, JG (Author) Other; Vitor Vasconcelos (Author) FCUP

Journal

Title: Continental Shelf Research

Vol. 130

Pages: 1-13

ISSN: 0278-4343

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 4 Citations

Scopus - 4 Citations

Other information

Authenticus ID: P-00M-A6Z

DOI: 10.1016/j.csr.2016.10.001

Abstract (EN): The Cabo Frio Upwelling System is one of the largest and most productive areas in southeastern Brazil. Although it is well-known that bacterial communities play a crucial role in the biogeochemical cycles and food chain of marine ecosystems, little is known regarding the microbial communities in the sediments of this upwelling region. In this research, we address the effect of different hydrological conditions on the biogeochemistry of sediments and the diversity of bacterial communities. Biogeochemistry profiles of sediments from four sampling stations along an inner-outer transect on the continental shelf were evaluated and denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA gene fragments was used to study the bacterial community composition in these sediments. Our sequencing analysis of excised bands identified Alpha- and Gammaproteobacteria, Bacteroidetes and bacteria belonging to the Firmicutes phyla as the phylogenetic groups, indicating the existence of great diversity in these marine sediments. In this multi-disciplinary study, the use of multivariate analysis was crucial for understanding how biogeochemical profiles influence bacterial community distribution. A Principal Component Analysis (PCA) indicated that the biogeochemical variables exhibited a clear spatial pattern that is mainly related to hydrological conditions. A Correspondence Analysis (CA) revealed an important association between certain taxonomic groups and specific sampling locations. Canonical Correspondence Analysis (CCA) demonstrated that the biogeochemistry influences the structure of the bacterial community in sediments. Among the bacterial groups identified, the most taxonomically diverse classes (Alphaproteobacteria and Gammaproteobacteria) were found to be distributed regardless of any studied biogeochemical variables influences, whereas other groups responded to biogeochemical conditions which, in turn, were influenced by hydrological conditions. This finding was observed for members of the two classes in the Bacteroidetes phylum, which were associated with either proteins or carbohydrates.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 13