Enrichment and physiological characterization of an anaerobic ammonium-oxidizing bacterium ‘Candidatus Brocadia sapporoensis’

Abstract

We successfully enriched a novel anaerobic ammonium-oxidizing (anammox) bacterium affiliated with the genus 'Candidatus Brocadia' with high purity (>90%) in a membrane bioreactor (MBR). The enriched bacterium was distantly related to the hitherto characterized 'Ca. Brocadia fulgida' and 'Ca. Brocadia sinica' with 96% and 93% of 16S ribosomal RNA gene sequence identity, respectively. The bacterium exhibited the common structural features of anammox bacteria and produced hydrazine in the presence of hydroxylamine under anoxic conditions. The temperature range of anammox activity was 20-45°C with a maximum activity at 37°C. The maximum specific growth rate (μ) was 0.0082h at 37°C, corresponding to a doubling time of 3.5 days. The half-saturation constant (K) for nitrite was 5±2.5μM. The anammox activity was inhibited by nitrite (IC=11.6mM) but not by formate and acetate. The major respiratory quinone was identified to be menaquinone-7 (MK-7). The enriched anammox bacterium shared nearly half of genes with 'Ca. Brocadia sinica' and 'Ca. Brocadia fulgida'. The enriched bacterium showed all known physiological characteristics of anammox bacteria and can be distinguished from the close relatives by its 16S rRNA gene sequence. Therefore, we proposed the name 'Ca. Brocadia sapporoensis' sp. nov.

Aggregation ability of three phylogenetically distant anammox bacterial species

“…J. caeni" (Ali et al, 2015a) and "Ca. B. sapporoensis" (Narita et al, 2017) were harvested in MBRs equipped with a hollow-fiber membrane unit composed of 300 polyethylene tubes (pore size, 0.1 μm; tube diameter, 1 mm; length, 70 mm) as previously described. These MBRs were fed with inorganic nutrient medium at nitrogen loading rates (NLRs) of 0.48-1.02 kg-N m −3 d −1 at 37°C.…”

“…sapporoensis". The TaqMan ® qPCR assays with specific primer sets and TaqMan ® probes (Table S1) were designed previously (Narita et al, 2017;Zhang et al, 2017a…”

Effect of temperature on microbial diversity and nitrogen removal performance of an anammox reactor treating anaerobically pretreated municipal wastewater

“…In addition, dissimilatory nitrate reduction to ammonium (DNRA), which Ca. Brocadia sapporoensis has the genetic potential to perform (Narita et al, 2017), was likely not occurring in the reactor (and/or it was too low to be noticed) since more nitrate was produced than it was consumed (as shown in Table 2).…”

Diversity and gene expression patterns of functional groups in sidestream and mainstream wastewater partial-nitritation anammox biofilms

“…Thus, the coexistence of different Brocadia, 323 The dominant hzsB ASV had an identical sequence to B. sapporoensis, which is frequently observed 332 in PNA bioreactors (Lotti, et al 2015b, Persson, et al 2014) and is considered relatively fast growing 333 (Lotti, et al 2015a). It has a maximum specific anammox activity at 37°C (Narita, et al 2017), which, 334 together with other factors like nitrogen load and partial nitritation rate, would explain the lower 335 nitrogen removal rates observed in the mainstream compared with the sidestream MBBR. A 336 considerable decrease of anammox rates with decreasing temperature has often been described in 337 PNA reactors (Gilbert, et al 2014, Laureni, et al 2016, Lotti, et al 2015b).…”