Fungi rather than bacteria drive early mass loss from fungal necromass regardless of particle size

• Published in: Environmental microbiology reports Vol. 16; no. 3; pp. e13280 - n/a
• Main Authors: Pérez‐Pazos, Eduardo, Beidler, Katilyn V., Narayanan, Achala, Beatty, Briana H., Maillard, François, Bancos, Alexandra, Heckman, Katherine A., Kennedy, Peter G.
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.06.2024
• Subjects: Agricultural Science, Forestry and Fisheries; Agricultural Sciences; Ascomycota - growth & development; Ascomycota - physiology; Bacteria - classification; Bacteria - genetics; Bacteria - growth & development; Bacteria - isolation & purification; Bacteria - metabolism; Biologi; Biological Sciences; Fungi - classification; Fungi - genetics; Fungi - growth & development; Fungi - physiology; Hydrogen-Ion Concentration; Lantbruksvetenskap och veterinärmedicin; Lantbruksvetenskap, skogsbruk och fiske; Markvetenskap; Microbiology; Mikrobiologi; Natural Sciences; Naturvetenskap; Particle Size; Soil Microbiology; Soil Science
• ISSN: 1758-2229; 1758-2229
• DOI: 10.1111/1758-2229.13280

Microbial necromass is increasingly recognized as an important fast‐cycling component of the long‐term carbon present in soils. To better understand how fungi and bacteria individually contribute to the decomposition of fungal necromass, three particle sizes (>500, 250–500, and <250 μm) of Hyaloscypha bicolor necromass were incubated in laboratory microcosms inoculated with individual strains of two fungi and two bacteria. Decomposition was assessed after 15 and 28 days via necromass loss, microbial respiration, and changes in necromass pH, water content, and chemistry. To examine how fungal–bacterial interactions impact microbial growth on necromass, single and paired cultures of bacteria and fungi were grown in microplates containing necromass‐infused media. Microbial growth was measured after 5 days through quantitative PCR. Regardless of particle size, necromass colonized by fungi had higher mass loss and respiration than both bacteria and uninoculated controls. Fungal colonization increased necromass pH, water content, and altered chemistry, while necromass colonized by bacteria remained mostly unaltered. Bacteria grew significantly more when co‐cultured with a fungus, while fungal growth was not significantly affected by bacteria. Collectively, our results suggest that fungi act as key early decomposers of fungal necromass and that bacteria may require the presence of fungi to actively participate in necromass decomposition. Dead fungal mycelium (also known as necromass) had higher mass loss, respiration, pH, and water content when colonized by fungi than by bacteria. When co‐cultured with a fungus, bacterial strains grew significantly more on necromass as the C source than when growing alone, while fungal growth was not significantly affected by bacteria.