Distribution of HNA and LNA bacterial groups in the Southwest Atlantic Ocean

Brazilian Journal of Microbiology

Luciana Andrade²  Alessandra M. Gonzalez²  Carlos Eduardo Rezende¹  Marina Suzuki¹  Jean Louis Valentin²  Rodolfo Paranhos² 

[1] ,Universidade Federal do Rio de Janeiro Instituto de Biologia Departamento de Biologia MarinhaRio de Janeiro RJ ,Brasil

关键词: bacterial abundance;    HNA bacteria;    LNA bacteria;    flow cytometry;    Southwest Atlantic Ocean;    abundância bacteriana;    bactérias HNA;    bactérias LNA;    citometria de fluxo;    Oceano Atlântico Sudoeste;   

DOI  :  10.1590/S1517-83822007000200028

来源: SciELO

【 摘 要 】

Bacterioplankton was studied in a large area of Southwest Atlantic Ocean between 13 and 25ºS and 28 and 42ºW. Samples were collected in 108 stations at 20 m depth. Bacteria were enumerated by flow cytometry after nucleic acid staining with syto13 and two subgroups were differentiated: low nucleic acid content (LNA) and high nucleic acid content (HNA) bacteria. Total bacterial numbers varied from 0.37 to 5.53 10(5) cells mL-1. HNA cells represented 15 to 70% of the total number while LNA cells represented 30 to 85%. Heterotrophic bacterial production was determined by incorporation of tritiated leucine and ranged from 2.7 to 171.07 ng C L-1 h-1. No significant correlation was found between abundance and production. Nevertheless with support of multivariate analysis between bacterial abundance, bacterial production, chlorophyll a and other oceanographic data the distribution of the groups in two different oceanic provinces could be explained by nutrient availability. HNA bacteria accounted for the high percentage of cells found in the area north of 19ºS, linked to higher temperature waters and riverine nutrients inputs. LNA bacteria were the dominant cells south of this latitude and were correlated to the higher values of nitrate found for the same area.

【 授权许可】

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