Oxygen gas derived oxygen does not affect the accuracy of 18O-labelled water approach for microbial carbon use efficiency. (May 2022)

• Record Type: Journal Article
• Authors: Wang, Zitong; Yang, Jingyi; Wang, Chao; Bai, Edith
• Is Part Of: Soil biology and biochemistry. Volume 168(2022)
• Publication Date: 2022-05
• Subjects: Oxygen isotope -- Oxygen gas -- Carbon use efficiency -- Metabolic water; Soil biochemistry -- Periodicals; Soil biology -- Periodicals; Sols -- Biochimie -- Périodiques; Sols -- Biologie -- Périodiques; Sols -- Microbiologie -- Périodiques; Bodembiologie; Biochemie; 631.46
• DOI: 10.1016/j.soilbio.2022.108649
• Languages: English
• ISSNs: 0038-0717

Abstract

Abstract: The 18 O-labelled-water incubation approach is the latest widely used method for soil microbial carbon use efficiency (CUE) estimation. This approach assumes oxygen used for microbial DNA synthesis is from growth medium water. However, whether the oxygen might be from oxygen gas (O2 ) is unknown. Here we compared the results of 18 O-labelled water and 18 O-labelled O2 incubation experiments following the standard procedure of soil microbial CUE measurement. Results indicated that 99.25% of the oxygen atoms in the newly synthesized microbial DNA after 48 h of incubation were derived from applied water, while 0.75% of the oxygen atoms were derived from O2 . Our study suggests the contribution of O2 to microbial DNA synthesis is negligible during short-term incubation and the 18 O-labelled-water approach is reliable for estimating soil microbial CUE for the tested forest soil. Highlights: O2 -derived O contributed less than 1% of newly synthesized DNA-O after 48 h soil incubation. Metabolic water did not contribute significantly to DNA synthesis in the tested soil. 18 O-labelled water approach is reliable for estimating soil microbial CUE.