TY - JOUR
T1 - NanoSIMS reveals unusual enrichment of acetate and propionate by an anammox consortium dominated by Jettenia asiatica
AU - Tao, Yu
AU - Huang, Xiaoli
AU - Gao, Dawen
AU - Wang, Xiaolong
AU - Chen, Chunhong
AU - Liang, Hong
AU - van Loosdrecht, Mark C.M.
PY - 2019
Y1 - 2019
N2 -
Anaerobic ammonium-oxidizing (anammox)bacteria convert ammonium and nitrite into N
2
in a chemolithoautotrophic way, meaning that they utilize CO
2
/HCO
3
solely as their carbon sources. Such autotrophic behavior limits their competitiveness with heterotrophic microorganisms in both natural environments and engineered systems. Recently, environmental metagenomic results have indicated the capability of anammox bacteria to metabolize short-chain fatty acids, further confirmed by limited experimental evidence based on highly enriched cultures. However, clear evidence is difficult to get because of the limits of traditional methodologies which rely on the availability of a pure anammox culture. In this study, we identified and quantified the uptake of acetate and propionate, on a single-cell level, by an anammox consortium that was dominated by Candidatus Jettenia asiatica (relative abundance of 96%). The consortium, growing in granular form with an average relative abundance of anammox bacteria of 96.0%, was firstly incubated in a
13
C-labelled acetate or propionate medium; then microtome sections were scanned by a nanometer-scale secondary ion mass spectrometer (NanoSIMS). The NanoSIMS scannings revealed that the consortium enriched acetate and propionate at a >10 times higher efficiency than bicarbonate incorporation. Our results also suggest that acetate or propionate was likely not assimilated by J. asiatica directly, but firstly oxidized to CO
2
, which then served as carbon sources for the follow-up autotrophy in J. asiatica cells. Furthermore, more [
15
N]ammonium was enriched by the propionate-fed consortium than the acetate-fed consortium despite that exactly the same amount of
13
C atoms were supplied. Our study strongly indicates an alternative lifestyle, namely organotrophy, in addition to chemolithoautotrophy of anammox bacteria, making it more versatile than often expected. It suggests that the niche of anammox bacteria in both natural and engineered ecosystems can be much broader than usual assumed. Recognising this is important for their role in wastewater treatment and the global nitrogen turn-over rates.
AB -
Anaerobic ammonium-oxidizing (anammox)bacteria convert ammonium and nitrite into N
2
in a chemolithoautotrophic way, meaning that they utilize CO
2
/HCO
3
solely as their carbon sources. Such autotrophic behavior limits their competitiveness with heterotrophic microorganisms in both natural environments and engineered systems. Recently, environmental metagenomic results have indicated the capability of anammox bacteria to metabolize short-chain fatty acids, further confirmed by limited experimental evidence based on highly enriched cultures. However, clear evidence is difficult to get because of the limits of traditional methodologies which rely on the availability of a pure anammox culture. In this study, we identified and quantified the uptake of acetate and propionate, on a single-cell level, by an anammox consortium that was dominated by Candidatus Jettenia asiatica (relative abundance of 96%). The consortium, growing in granular form with an average relative abundance of anammox bacteria of 96.0%, was firstly incubated in a
13
C-labelled acetate or propionate medium; then microtome sections were scanned by a nanometer-scale secondary ion mass spectrometer (NanoSIMS). The NanoSIMS scannings revealed that the consortium enriched acetate and propionate at a >10 times higher efficiency than bicarbonate incorporation. Our results also suggest that acetate or propionate was likely not assimilated by J. asiatica directly, but firstly oxidized to CO
2
, which then served as carbon sources for the follow-up autotrophy in J. asiatica cells. Furthermore, more [
15
N]ammonium was enriched by the propionate-fed consortium than the acetate-fed consortium despite that exactly the same amount of
13
C atoms were supplied. Our study strongly indicates an alternative lifestyle, namely organotrophy, in addition to chemolithoautotrophy of anammox bacteria, making it more versatile than often expected. It suggests that the niche of anammox bacteria in both natural and engineered ecosystems can be much broader than usual assumed. Recognising this is important for their role in wastewater treatment and the global nitrogen turn-over rates.
KW - Acetate
KW - Anaerobic ammonium oxidation
KW - Anammox
KW - Propionate
UR - http://www.scopus.com/inward/record.url?scp=85065530886&partnerID=8YFLogxK
U2 - 10.1016/j.watres.2019.05.006
DO - 10.1016/j.watres.2019.05.006
M3 - Article
AN - SCOPUS:85065530886
SN - 0043-1354
VL - 159
SP - 223
EP - 232
JO - Water Research
JF - Water Research
ER -