2019_EJRNL_PP_KAI-LING_PAN_1.pdf
Terbatas Lili Sawaludin Mulyadi
» ITB
Terbatas Lili Sawaludin Mulyadi
» ITB
Nitrification failure of wastewater treatment plants (WWTPs) in cold season calls into investigations of
the functional ammonia-oxidizing microorganisms (AOMs). In this study, we report the abundance of
ammonia-oxidizing archaea (AOA), bacteria (AOB) and complete ammonia-oxidizing (comammox)
Nitrospira in 23 municipal WWTPs in cold season, and explore the correlations between AOMs abundance and their relative contribution to nitrification. The copy numbers of AOA and AOB amoA gene
ranged from 2.42 107 to 2.47 109 and 5.54 106 to 3.31 109 copies/g sludge, respectively. The
abundance of amoA gene of Candidatus Nitrospira inopinata, an important strain of comammox Nitrospira, was stable with averaged abundance of 8.47 106 copies/g sludge. DNA-based stable isotope
probing (DNA-SIP) assays were conducted with three typical WWTPs in which the abundance of AOA was
lower than, similar to and higher than that of AOB, respectively. The results showed that considerable
13C-assimilation by AOA was detected during active nitrification in all WWTPs, whereas just a much
lesser extent of 13C-incorporation by AOB and comammox Nitrospira was found in one WWTP. Highthroughput sequencing with 13C-labeled DNA also showed the higher reads abundance of AOA than
AOB and comammox Nitrospira. Nitrososphaera viennensis was the dominant active AOA, while Nitrosomonas oligotropha and Nitrosomonas europaea were identified as active AOB. The results obtained
suggest that AOA, rather than AOB and comammox Nitrospira, dominate ammonia oxidation in WWTPs
in cold season despite the numerical relationships of AOMs.