TY - JOUR

T1 - Substrate control of sulphur utilisation and microbial stoichiometry in soil: Results of 13C, 15N, 14C, and 35S quad labelling

AU - Ma, Qingxu

AU - Kuzyakov, Yakov

AU - Pan, Wankun

AU - Tang, Sheng

AU - Chadwick, David R.

AU - Wen, Yuan

AU - Hill, Paul W.

AU - Macdonald, Andy

AU - Ge, Tida

AU - Si, Linlin

AU - Wu, Lianghuan

AU - Jones, Davey L.

N1 - © 2021. The Author(s), under exclusive licence to International Society for Microbial Ecology.

PY - 2021/11

Y1 - 2021/11

N2 - Global plant sulphur (S) deficiency is increasing because of a reduction in sulphate-based fertiliser application combined with continuous S withdrawal during harvest. Here, we applied 13C, 15N, 14C, and 35S quad labelling of the S-containing amino acids cysteine (Cys) and methionine (Met) to understand S cycling and microbial S transformations in the soil. The soil microorganisms absorbed the applied Cys and Met within minutes and released SO42− within hours. The SO42− was reutilised by the MB within days. The initial microbial utilisation and SO42− release were determined by amino acid structure. Met released 2.5-fold less SO42− than Cys. The microbial biomass retained comparatively more C and S from Met than Cys. The microorganisms decomposed Cys to pyruvate and H2S whereas they converted Met to α-ketobutyrate and S-CH3. The microbial stoichiometries of C, N, and S derived from Cys and Met were balanced after 4 d by Cys-derived SO42− uptake and Met-derived CO2 release. The microbial C:N:S ratio dynamics showed rapid C utilisation and loss, stable N levels, and S accumulation. Thus, short-term organic S utilisation by soil microorganisms is determined by amino acid structure whilst long-term organic S utilisation by soil microorganisms is determined by microbially controlled stoichiometry.

AB - Global plant sulphur (S) deficiency is increasing because of a reduction in sulphate-based fertiliser application combined with continuous S withdrawal during harvest. Here, we applied 13C, 15N, 14C, and 35S quad labelling of the S-containing amino acids cysteine (Cys) and methionine (Met) to understand S cycling and microbial S transformations in the soil. The soil microorganisms absorbed the applied Cys and Met within minutes and released SO42− within hours. The SO42− was reutilised by the MB within days. The initial microbial utilisation and SO42− release were determined by amino acid structure. Met released 2.5-fold less SO42− than Cys. The microbial biomass retained comparatively more C and S from Met than Cys. The microorganisms decomposed Cys to pyruvate and H2S whereas they converted Met to α-ketobutyrate and S-CH3. The microbial stoichiometries of C, N, and S derived from Cys and Met were balanced after 4 d by Cys-derived SO42− uptake and Met-derived CO2 release. The microbial C:N:S ratio dynamics showed rapid C utilisation and loss, stable N levels, and S accumulation. Thus, short-term organic S utilisation by soil microorganisms is determined by amino acid structure whilst long-term organic S utilisation by soil microorganisms is determined by microbially controlled stoichiometry.

U2 - 10.1038/s41396-021-00999-7

DO - 10.1038/s41396-021-00999-7

M3 - Article

C2 - 33976391

VL - 15

SP - 3148

EP - 3158

JO - The ISME Journal

JF - The ISME Journal

SN - 1751-7370

IS - 11

ER -