EGU21-7732, updated on 21 Apr 2023
EGU General Assembly 2021
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Microbial response to cooling

Jörg Schnecker1, Felix Spiegel1, Lucia Fuchslueger1, Yue Li1,2, and Andreas Richter1
Jörg Schnecker et al.
  • 1Centre for Microbiology and Environmental Systems Science, University of Vienna, Austria
  • 2South China Botanical Garden, Chinese Academy of Sciences, China

In temperate soil systems microbial biomass often increases during winter and decreases again in spring. This build up and release of microbial carbon could potentially lead to a build-up of stabilized soil carbon during winter times. The mechanism behind the increase in microbial carbon is not well understood. In this laboratory incubation study, we looked into microbial physiology as well as microbial glucose uptake and partitioning during cooling. Soils from a temperate forest and agricultural system were cooled down from field temperature of 11°C to 1°C. We added 13C-labelled glucose immediately and after an acclimation phase of 7 days and traced the 13C into microbial biomass, CO2 respired from the soil and phospholipid fatty acids. In addition we determined microbial growth using 18O-incorporation into DNA.

First results show that while total respiration was strongly reduced when soils were cooled, glucose-derived respiration was as high in soils at 1°C as at 11°C. The same general pattern was found in soils during fast cooling and after an acclimation phase in agricultural and forest soils. We also saw an increased investment of glucose-derived carbon in unsaturated PLFAs. Since unsaturated fatty acids retain fluidity at lower temperatures compared to saturated fatty acids, this could be interpreted as precaution to reduced temperatures and potential freezing.

Our results show a distinct response of the soil microbial community to cooling. The maintained glucose-derived respiration and incorporation into PLFAs at low temperatures compared to field temperature might indicate a preferential use of labile C forms during cooling. Moreover, the 13C incorporation into PLFAs may signal the buildup of cooling resistant cell membranes. These findings will be discussed with results from the 13C label tracing into microbial biomass, extractable organic carbon and total soil carbon as well as data on microbial growth and carbon use efficiency.

How to cite: Schnecker, J., Spiegel, F., Fuchslueger, L., Li, Y., and Richter, A.: Microbial response to cooling, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-7732,, 2021.


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