Elevated CO2 influences microbial carbon and nitrogen cycling
1 State Key Laboratory of Applied Microbiology (Ministry—Guangdong Province Jointly Breeding Base), South China, Guangdong Institute of Microbiology, Guangzhou, China
2 Institute for Environmental Genomics and Department of Botany and Microbiology, University of Oklahoma, Norman, USA
3 Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, USA
4 Department of Forest Resources, University of Minnesota, St. Paul, USA
5 Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, USA
6 Department of Environmental Science and Engineering, Tsinghua University, Beijing, China
BMC Microbiology 2013, 13:124 doi:10.1186/1471-2180-13-124Published: 29 May 2013
Elevated atmospheric CO2 (eCO2) has been shown to have significant effects on terrestrial ecosystems. However, little is known about its influence on the structure, composition, and functional potential of soil microbial communities, especially carbon (C) and nitrogen (N) cycling. A high-throughput functional gene array (GeoChip 3.0) was used to examine the composition, structure, and metabolic potential of soil microbial communities from a grassland field experiment after ten-year field exposure to ambient and elevated CO2 concentrations.
Distinct microbial communities were established under eCO2. The abundance of three key C fixation genes encoding ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), carbon monoxide dehydrogenase (CODH) and propionyl-CoA/acetyl-CoA carboxylase (PCC/ACC), significantly increased under eCO2, and so did some C degrading genes involved in starch, cellulose, and hemicellulose. Also, nifH and nirS involved in N cycling were significantly stimulated. In addition, based on variation partitioning analysis (VPA), the soil microbial community structure was largely shaped by direct and indirect eCO2-driven factors.
These findings suggest that the soil microbial community structure and their ecosystem functioning for C and N cycling were altered dramatically at eCO2. This study provides new insights into our understanding of the feedback response of soil microbial communities to elevated CO2 and global change.