Microbial utilization of simple and complex carbon compounds in a temperate forest soil. (October 2022)

• Record Type: Journal Article
• Authors: Martinović, Tijana; Mašínová, Tereza; López-Mondéjar, Rubén; Jansa, Jan; Štursová, Martina; Starke, Robert; Baldrian, Petr
• Is Part Of: Soil biology and biochemistry. Volume 173(2022)
• Publication Date: 2022-10
• Subjects: Soil ecology -- Fungi -- Bacteria -- Decomposition -- Carbon utilization -- Biopolymers -- Exudates; Soil biochemistry -- Periodicals; Soil biology -- Periodicals; Sols -- Biochimie -- Périodiques; Sols -- Biologie -- Périodiques; Sols -- Microbiologie -- Périodiques; Bodembiologie; Biochemie; 631.46
• DOI: 10.1016/j.soilbio.2022.108786
• Languages: English
• ISSNs: 0038-0717

Abstract

Abstract: Forest soil processes carried out by microorganisms are critical for the global carbon (C) cycle and climate. Characterizing the utilization of differently recalcitrant C sources is an important step towards understanding the ecosystem-level function of microorganisms in temperate forest soils. Here, using stable-isotope probing (SIP), we tracked C incorporation into bacterial and fungal biomass by quantifying 13 C incorporation into phospholipid fatty acids (PLFA-SIP), its respiration (i.e., content in the produced CO2 ) and C accumulation by individual microbial taxa (DNA-SIP), following the addition of 13 C-labelled substrates of different recalcitrance (citric acid, glucose, chitin, cellulose, hemicellulose, and plant biomass) in microcosms. The highest 13 C respiration was observed after the addition of the low-molecular-mass substrates citric acid and glucose, while the highest 13 C incorporation into microbial biomass was observed during growth on chitin. Communities of fungi and bacteria that incorporated 13 C of various origins into their biomass differed from the original soil communities, as well as between treatments. The most distinct microbial community was observed in microcosms containing 13 C-chitin, indicating its utilization by both fungi and bacteria. Bacterial taxa were more often versatile, incorporating C of various origins, while there was a higher share of fungi that were specialists. Together, our results show that low-molecular-mass compounds that belong to typical root exudates are more readily respired, while the C from biopolymers studied was relatively more incorporated into microbial biomass. Various C sources are targeted by distinct microbial communities, although their composition partly overlaps due to the existence of generalist bacteria and fungi that are capable of utilizing various C sources. Graphical abstract: Image 1 Highlights: Carbon from compounds contained in root exudates is most readily respired. The addition of chitin results in the fastest C incorporation in microbial biomass. A higher share of C from biopolymers studied is incorporated into microbial biomass. There are more substrate specialists among fungi than bacteria. Carbon from chitin is incorporated by specific fungi and bacteria.