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N itrospina ‐like bacteria are the main drivers of nitrite oxidation in the seasonal upwelling area of the E astern S outh P acific ( C entral C hile ∼36° S )
Author(s) -
Levipan Héctor A.,
Molina Verónica,
Fernandez Camila
Publication year - 2014
Publication title -
environmental microbiology reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.229
H-Index - 69
ISSN - 1758-2229
DOI - 10.1111/1758-2229.12158
Subject(s) - upwelling , bacteria , nitrite , pyrosequencing , environmental chemistry , nitrate , nitrification , biology , 16s ribosomal rna , microbial population biology , water column , oceanography , ecology , chemistry , nitrogen , biochemistry , geology , gene , genetics , organic chemistry
Summary Aerobic nitrite oxidation in marine environments plays a key role in the nitrification process. Marine bacteria involved in this nitrate‐producing process have however been seldom studied compared with the ammonia‐oxidizing community. Here, we report for the first time the community structure of aerobic nitrite‐oxidizing bacteria ( NOB ) in the seasonal upwelling and oxygen‐deficient area off C entral C hile. Analysis of 16 S rRNA by tag pyrosequencing was combined with specific quantitative polymerase chain reaction ( qPCR ) and reverse transcription qPCR in summer and wintertime. N itrospina ‐like bacteria were the only known NOB detected by means of pyrosequencing between 30 and 80 m depth, accounting for up to 5% of total bacteria. This guild was represented by 11 and 7 operational taxonomic units (97% cut‐off) in winter and summertime respectively. N itrospina ‐like bacteria were phylogenetically related to sequences retrieved from coastal upwelling, oxygen minimum zones and deep‐sea environments. This group was also detected by qPCR with abundances that increased with depth throughout the water column. Importantly, N itrospina from surface layers showed low abundances but high 16 S rRNA : rDNA ratios and mainly in summertime. Overall, our results highlight the seasonal variability between the structure and physiological state of this community and suggest a significant role of N itrospina in the nitrogen cycle of seasonal upwelling areas.