Table 2.
Identification of cultured nitrate/nitrite ammonifiers retrieved from estuarine sediments.
| Taxonomy | Isolate number | Type strain with the highest 16S rRNA gene sequence similarity to query sequences | Nitrate metabolism | nrfA gene amplification | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Species name | % sim | Accession number | NO−3 reduction to NO−2 | Denitrification | DNRA | N2O production (%)a | F1-7R1b | F2-7R1b | F2aw-7R1c | ||
| Alphaproteobacteria | |||||||||||
| Rhodobacterales | R-52651 | Celeribacter baekdonensis L-6T | 100 | HM997022 | + | − | + | 0–1.1 | − | + | − |
| Rhodospirillales | R-52913 | Thalassospira lucentensis DSM 14000T | 99.6 | AM294944 | + | − | + | 0–0.3 | − | − | − |
| R-52699 | 99.6 | AM294944 | + | − | + | 0–0.7 | − | − | − | ||
| Gammaproteobacteria | |||||||||||
| Aeromonadales | R-52674 | Oceanisphaera donghaensis BL1T | 99.77 | DQ190441 | + | − | + | 2–2.1 | + | + | − |
| Alteromonadales | R-52649 | Shewanella colwelliana ATCC 39565T | 100 | AY653177 | + | − | + | 0.3–1.3 | − | + | − |
| R-52673 | Shewanella marisflavi SW 117T | 100 | AY485224 | + | − | + | 0.8–1.4 | + | + | − | |
| Enterobacteriales | R-52910 | Citrobacter gillenii CDC 4693-86T | 99.9 | AF025367 | + | − | + | 0.6–2.9 | + | + | + |
| Oceanospirillales | R-52914 | Halomonas denitrificans M29T | 98.9 | AM229317 | + | − | + | 2.4–2.9 | + | + | + |
| Vibrionales | R-52677 | Vibrio alginolyticus NBRC 15630T | 99.7 | CP006718 | + | − | + | 0.8–2 | + | + | + |
| R-52915 | 99.4 | CP006718 | + | − | + | 0.9–2.1 | + | + | + | ||
| R-52696 | 99.4 | CP006718 | + | − | + | 1.2–1.7 | + | + | + | ||
| R-52683 | Vibrio diabolicus HE800T | 99.4 | X99762 | + | − | + | 1–1.9 | − | + | − | |
| R-52669 | Vibrio neocaledonicus NC470T | 99.4 | JQ934828 | + | − | + | 0.7–2.4 | − | − | − | |
| R-52688 | 99.79 | JQ934828 | + | − | + | 0.7–2.4 | + | + | + | ||
| R-66650 | Vibrio rumoiensis S-1T | 100 | AB013297 | + | − | + | 0.3–2 | + | + | − | |
Taxonomic assignment to genus level based on the 16S rRNA gene sequence analysis, observed dissimilatory reduction of nitrogenous compounds, amounts of nitrous oxide produced, and nrfA amplification results are represented. Reduction of nitrate to nitrite and DNRA have been tested in two different growth conditions (complex or mineral medium).
a
Percentage of trace amounts of nitrous oxide detected in both 1/10 marine both and mineral media supplemented with 5 mM nitrate.
b
nrfA gene amplification primers (505 bp and 231 bp amplicon respectively) from Mohan et al. (2004).
c
nrfA gene amplification primers (269 bp amplicon) from Welsh et al. (2014).