Whole-Community Metagenomics in Two Different Anammox Configurations: Process Performance and Community Structure

Abstract

Anaerobic ammonia oxidation (anammox) combined with partial nitritation (PN) is an innovative treatment process for energy-efficient nitrogen removal from wastewater. In this study, we used genome-based metagenomics to investigate the overall community structure and anammox species enriched in suspended growth (SGR) and attached growth packed-bed (AGR) anammox reactors after 220 days of operation. Both reactors removed more than 85% of the total inorganic nitrogen. Metagenomic binning and phylogenetic analysis revealed that two anammox population genomes, affiliated with the genus Candidatus Brocadia, were differentially abundant between the SGR and AGR. Both of the genomes shared an average nucleotide identify of 83%, suggesting the presence of two different species enriched in both of the reactors. Metabolic reconstruction of both population genomes revealed key aspects of their metabolism in comparison to known anammox species. The community composition of both the reactors was also investigated to identify the presence of flanking community members. Metagenomics and 16S rRNA gene amplicon sequencing revealed the dominant flanking community members in both reactors were affiliated with the phyla Anaerolinea, Ignavibacteria, and Proteobacteria. Findings from this research adds two new species, Ca. Brocadia sp. 1 and Ca. Brocadia sp. 2, to the genus Ca. Brocadia and sheds light on their metabolism in engineered ecosystems.

The pH dependency of N‐converting enzymatic processes, pathways and microbes: effect on net N2O production

“…Anammox is catalysed by the sequential activity of the enzymes NIR, hydrazine synthase (HZS) and hydrazine dehydrogenase (HDH) (Kartal et al, 2013). All three enzymes are located in the anammoxosome, an intra-riboplasmic compartment (Niftrik et al, 2004;Kartal et al, 2011;Bagchi et al, 2016;Bhattacharjee et al, 2017). The lumen of the anammoxosome is separated by three single bilayer membranes from the environment (van Niftrik et al, 2008).…”

Temperature modulates stress response in anammox reactors

“…The microbial community in the biofilm carriers consisted of a diverse assemblage of taxa, many of which are typical for mainstream anammox WWTP 17, 18, 30 . Members of Proteobacteria, Chloroflexi, Planctomycetes and Actinobacteria dominated the biofilms, accounting for approximately 70% of the total community composition, However, Proteobacteria represented the largest Phylum of the community accounting for ∼40% of the total abundance (Figure 3A).…”

“…So far, the majority of these studies were focusing on how disturbances affect the autotrophic N removal efficiency on the process level but did not investigate effects on microbial guild dynamics and their respective stress response, which might have led to the observed performance failures and/or recovery processes. Metagenomic shotgun sequencing allows to gain a comprehensive insight in the functional potential of communities involved in the anammox process 17, 18, 30, 31 but is unlikely to yield useful information on short-term disturbance effects, which, in most of the cases, are not leading to shifts in the microbial community composition. Therefore we focus on biochemical measurements in combination with metatranscriptomics, which can provide important information on the response of microbes in a variable environment 32 .…”

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

“…The larger fraction of HDB in the mainstream suggests more extensive 279 competition for NO2between AMX and HDB; in addition, potential nitrogen loops of nitrification, 280 anammox, denitrification and DNRA may occur (Speth, et al 2016). populations has also been reported in PNA systems (Bhattacharjee, et al 2017, Laureni, et al 2019, 318 Persson, et al 2014. Nitrospira is a heterogeneous group, which not only represents a nitrite 319 oxidising potential, but also contains populations capable of using a myriad of electron donors and -320 acceptors (Daims, et al 2015, Koch, et al 2015, van Kessel, et al 2015 and the same has also been 321 shown for AMX (Hu, et al 2019, Kartal, et al 2007, Strous, et al 2006 2008) and AOB (Bock, et al 1995).…”