TY - JOUR
T1 - Variability of nitrifying communities in surface coastal waters of the Eastern South Pacific (~36°S)
AU - Levipan, Héctor A.
AU - Molina, Verónica
AU - Anguita, Cristóbal
AU - Rain-Franco, Angel
AU - Belmar, Lucy
AU - Fernandez, Camila
N1 - Funding Information:
This research was supported by FONDECYT grants 1150891 and 1110824 (CONICYT, Chile). We acknowledge partial financial support from FONDAP-INCAR center (CONICYT 15110027) and PFB-31 COPAS SA. We thank the captain and crew of the R/V Kay-Kay II for their valuable assistance and support. This study is part of the French-Chilean project LIA-MORFUN. H. L. was funded by CONICYT grants 24121239 and 21090032, and the mobility program funded by the French embassy in Chile. We thank the time-series station program of the COPAS center for providing a sampling platform and data.
PY - 2016/10/1
Y1 - 2016/10/1
N2 - We report the seasonal and single-diurnal variability of potentially active members of the prokaryote community in coastal surface waters off central Chile and the relationship between nitrifiers and solar radiation by combining 16S cDNA-based pyrosequencing, RTqPCR of specific gene markers for nitrifiers (amoA, for general AOA, AOA-A, AOA-B, Nitrosopumilus maritimus and beta-AOB; and 16S rRNA gene for Nitrospina-like NOB), and solar irradiance measurements. We also evaluated the effects of artificial UVA-PAR and PAR spectra on nitrifiers by RT-qPCR. All nitrifiers (except AOA-B ecotype) were detected via RTqPCR but AOA was the only group detected by pyrosequencing. Results showed high variability in their transcriptional levels during the day which could be associated to sunlight intensity thresholds in winter although AOA and Nitrospina-like NOB transcript number were also potentially related with environmental substrate availability. Only N. maritimus amoA transcripts showed a significant negative correlation with solar irradiances in both periods. During springsummer, Nitrospina transcripts decreased at higher sunlight intensities, whereas the opposite was found during winter under natural (in situ) and artificial light experiments. In summary, a nitrifying community with variable tolerance to solar radiation is responsible for daily nitrification, and was particularly diverse during winter in the study area.
AB - We report the seasonal and single-diurnal variability of potentially active members of the prokaryote community in coastal surface waters off central Chile and the relationship between nitrifiers and solar radiation by combining 16S cDNA-based pyrosequencing, RTqPCR of specific gene markers for nitrifiers (amoA, for general AOA, AOA-A, AOA-B, Nitrosopumilus maritimus and beta-AOB; and 16S rRNA gene for Nitrospina-like NOB), and solar irradiance measurements. We also evaluated the effects of artificial UVA-PAR and PAR spectra on nitrifiers by RT-qPCR. All nitrifiers (except AOA-B ecotype) were detected via RTqPCR but AOA was the only group detected by pyrosequencing. Results showed high variability in their transcriptional levels during the day which could be associated to sunlight intensity thresholds in winter although AOA and Nitrospina-like NOB transcript number were also potentially related with environmental substrate availability. Only N. maritimus amoA transcripts showed a significant negative correlation with solar irradiances in both periods. During springsummer, Nitrospina transcripts decreased at higher sunlight intensities, whereas the opposite was found during winter under natural (in situ) and artificial light experiments. In summary, a nitrifying community with variable tolerance to solar radiation is responsible for daily nitrification, and was particularly diverse during winter in the study area.
UR - http://www.scopus.com/inward/record.url?scp=84985911232&partnerID=8YFLogxK
U2 - 10.1111/1758-2229.12448
DO - 10.1111/1758-2229.12448
M3 - Article
AN - SCOPUS:84985911232
VL - 8
SP - 851
EP - 864
JO - Environmental Microbiology Reports
JF - Environmental Microbiology Reports
SN - 1758-2229
IS - 5
ER -