New Insight Into the Interspecies Shift of Anammox Bacteria Ca. "Brocadia" and Ca. "Jettenia" in Reactors Fed With Formate and Folate

• Published in: Frontiers in microbiology Vol. 12; p. 802201
• Main Authors: Kallistova, Anna, Nikolaev, Yury, Grachev, Vladimir, Beletsky, Alexey, Gruzdev, Evgeny, Kadnikov, Vitaly, Dorofeev, Alexander, Berestovskaya, Julia, Pelevina, Anna, Zekker, Ivar, Ravin, Nikolai, Pimenov, Nikolai, Mardanov, Andrey
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 03.02.2022
• Subjects: anammox bacteria; Candidatus “Brocadia”; Candidatus “Jettenia”; folate; formate; interspecies shift; Microbiology; anammox bacteria; formate; interspecies shift; folate; Candidatus “Jettenia”; Candidatus “Brocadia”
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2021.802201

The sensitivity of anaerobic ammonium-oxidizing (anammox) bacteria to environmental fluctuations is a frequent cause of reactor malfunctions. It was hypothesized that the addition of formate and folate would have a stimulating effect on anammox bacteria, which in turn would lead to the stability of the anammox process under conditions of a sharp increase in ammonium load, i.e., it helps overcome a stress factor. The effect of formate and folate was investigated using a setup consisting of three parallel sequencing batch reactors equipped with a carrier. Two runs of the reactors were performed. The composition of the microbial community was studied by the 16S rRNA gene profiling and metagenomic analysis. Among anammox bacteria, "Brocadia" spp. dominated during the first run. A stimulatory effect of folate on the daily nitrogen removal rate (dN) was identified. The addition of formate led to progress in dissimilatory nitrate reduction and stimulated the growth of "Jettenia" spp. The spatial separation of two anammox species was observed in the formate reactor: "Brocadia" occupied the carrier and "Jettenia"-the walls of the reactors. Biomass storage at low temperature without feeding led to an interspecies shift in anammox bacteria in favor of "Jettenia." During the second run, a domination of "Jettenia" spp. was recorded along with a stimulating effect of formate, and there was no effect of folate on dN. A comparative genome analysis revealed the patterns suggesting different strategies used by "Brocadia" and "Jettenia" spp. to cope with environmental changes.