The microbial characterization of a hydroponic treatment step for domestic wastewater - towards an expanded view on the plant-microbial hydroecology

• The aim of this study was to explore the microbial composition in the hydroponic step of a pilot plant for treatment of domestic wastewater under temperate climate conditions. The pilot plant was designed for nitrogen removal and operated at constant conditions. The microbial composition was investigated over a period of 6 month,; using fluorescence in situ hybridization (FISH) to identify key microbial groups. Nitrification rate measurements confirmed the presence and activity of aerobic nitrifying populations. The FISH analysis demonstrated that Proteobacteria, followed by Nitrospirae and Planctomycetes, represented the three most abundant bacterial groups. Interestingly, further FISH studies suggested the presence of one other bacterial group associated with ammonium-oxidizing processes: anaerobic ammonium-oxidizing bacteria within the Planctomycetales. This suggests that the nitrogen turnover in hydroponics systems may be attributed to more complex processes than previous models based only on those performed by aerobic ammonium-oxidizing bacteria.

Nyckelord

biological wastewater treatment

hydroponics

rhizosphere microbiology

nitrification

microbial community structure

FISH

Betaproteobacteria

Archaea

Planctomycetales

anammox-bacteria

in-situ detection

targeted oligonucleotide probes

ammonium-oxidizing

bacteria

gram-positive bacteria

dna g+c content

nitrifying bacteria

diversity

hybridization

community

biofilm

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)