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Mimicking microbial interactions under nitrate‐reducing conditions in an anoxic bioreactor: enrichment of novel Nitrospirae bacteria distantly related to Thermodesulfovibrio
Author(s) -
Arshad Arslan,
Dalcin Martins Paula,
Frank Jeroen,
Jetten Mike S. M.,
Op den Camp Huub J. M.,
Welte Cornelia U.
Publication year - 2017
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.13977
Subject(s) - anammox , biology , candidatus , biogeochemical cycle , anoxic waters , nitrogen cycle , microbial population biology , archaea , environmental chemistry , nitrate , ecology , bacteria , denitrification , 16s ribosomal rna , nitrogen , denitrifying bacteria , chemistry , organic chemistry , genetics
Summary Microorganisms are main drivers of the sulfur, nitrogen and carbon biogeochemical cycles. These elemental cycles are interconnected by the activity of different guilds in sediments or wastewater treatment systems. Here, we investigated a nitrate‐reducing microbial community in a laboratory‐scale bioreactor model that closely mimicked estuary or brackish sediment conditions. The bioreactor simultaneously consumed sulfide, methane and ammonium at the expense of nitrate. Ammonium oxidation occurred solely by the activity of anammox bacteria identified as Candidatus Scalindua brodae and Ca . Kuenenia stuttgartiensis. Fifty‐three percent of methane oxidation was catalyzed by archaea affiliated to Ca . Methanoperedens and 47% by Ca . Methylomirabilis bacteria. Sulfide oxidation was mainly shared between two proteobacterial groups. Interestingly, competition for nitrate did not lead to exclusion of one particular group. Metagenomic analysis showed that the most abundant taxonomic group was distantly related to Thermodesulfovibrio sp. (87–89% 16S rRNA gene identity, 52–54% average amino acid identity), representing a new family within the Nitrospirae phylum. A high quality draft genome of the new species was recovered, and analysis showed high metabolic versatility. Related microbial groups are found in diverse environments with sulfur, nitrogen and methane cycling, indicating that these novel Nitrospirae bacteria might contribute to biogeochemical cycling in natural habitats.