Microbial community responses determine how soil–atmosphere exchange of carbonyl sulfide, carbon monoxide, and nitric oxide responds to soil moisture

Abstract

Abstract. Carbonyl sulfide (OCS) plays an important role in the global sulfur cycle and is relevant for climate change due to its role as a greenhouse gas, in aerosol formation and atmospheric chemistry. The similarities of the carbon dioxide (CO2) and OCS molecules within chemical and plant metabolic pathways have led to the use of OCS as a proxy for global gross CO2 fixation by plants (gross primary production, GPP). However, unknowns such as the OCS exchange from soils, where simultaneous OCS production (POCS) and consumption (UOCS) occur, currently limits the use of OCS as a GPP proxy. We estimated POCS and UOCS by measuring net fluxes of OCS, carbon monoxide (CO), and nitric oxide (NO) in a dynamic chamber system fumigated with air containing different mixing ratios [OCS]. Nine soils with different land use were rewetted and soil–air exchange was monitored as soils dried out to assess responses to changing moisture. A major control of OCS exchange was the total amount of available sulfur in the soil. POCS production rates were highest for soils at WFPS (water-filled pore space) >60 % and rates were negatively related to thiosulfate concentrations. These moist soils switched from a net source to a net sink activity at moderate moisture levels (WFPS 15 % to 37 %). For three soils we measured NO and CO mixing ratios at different mixing ratios of OCS and revealed that NO and potentially CO exchange rates are linked to UOCS at moderate soil moisture. High nitrate concentrations correlated with maximum OCS release rates at high soil moisture. For one of the investigated soils, the moisture and OCS mixing ratio was correlated with different microbial activity (bacterial 16S rRNA, fungal ITS RNA relative abundance) and gene transcripts of red-like cbbL and amoA.

Enumeration of Chemoorganotrophic Carbonyl Sulfide (COS)-degrading Microorganisms by the Most Probable Number Method

“…Nevertheless, we cannot deny the possibility that there was a bias in the media used for MPN, which may have influenced the culturability of COSdegrading microbes. Recent studies demonstrated the fungal contribution to COS uptake in soil environments (Masaki et al, 2016;Behrendt et al, 2019). It is important to note that we observed aggregates of fungal hyphae in several MPN cultures from soil samples; however, due to the conditions of our media, we were unable to distinguish the fungal activity of COS degradation from bacterial activity.…”

“…Although the physiological mechanisms of COS degradation and estimations of the global uptake of atmospheric COS by vegetation have been examined (Whelan et al, 2018), limited information is still currently available on soil microorganisms. The significance of soil as a source and sink of COS remains unclear (Whelan et al, 2016; because COS exchange between soil and the atmosphere is the net result of the uptake and production of COS, and both processes are affected by a number of environmental parameters, including temperature, moisture, porosity, biomass, and microbial community (Kesselmeier et al, 1999;Yi et al, 2007;Van Diest and Kesselmeier, 2008;Bunk et al, 2017;Behrendt et al, 2019;Meredith et al, 2019). Prokaryotic and fungal activities strongly contribute to COS degradation in soil (Kato et al, 2008;Masaki et al, 2016;Meredith et al, 2019).…”

The Characteristics of Carbon, Nitrogen and Sulfur Transformation During Cattle Manure Composting—Based on Different Aeration Strategies

“…It’s reported that there might be certain SO 2 release and concentration at locations with large quantities of manure storage, like animal barns [20]. Elliott and Travis [21] reported the chemical combinations such as CO 2 , H 2 S, and SO 2 can form carbonyl sulfide (COS), which plays an important role in the global sulfur cycle and is relevant for climate change due to its role as a greenhouse gas, in aerosol formation and atmospheric chemistry [22]. It has been reported that COS can be detected in the headspace above feedlot compost [21].…”

Soil Redox Controls CO2, CH4 and N2O Efflux from White-Rot Fungi in Temperate Forest Ecosystems

“…Under oxic conditions, nitrification dominates over denitrification in mediating N 2 O production [ 3 ]. Most nitrifiers are chemoautotrophic organisms (bacteria), abundant in organic matter-rich forest soils [ 4 , 5 ]. Under anoxic conditions, denitrification is the most important for N 2 O production [ 6 ].…”