Unraveling the influence of microbial necromass on subsurface microbiomes: metabolite utilization and community dynamics

作者：Brianna K. Finley, Brandon C. Enalls, Markus de Raad, M. Said, Mingfei Chen, Dominique C. Joyner, Terry C. Hazen, Trent R. Northen, Romy Chakraborty · 发表于：ISME Communications · 年份：2025 · DOI：10.1093/ismeco/ycaf006 · 被引用次数：15 · 研究领域：Microbial Community Ecology and Physiology、Gut microbiota and health、Environmental DNA in Biodiversity Studies

Abstract The role of microbial necromass (nonliving microbial biomass), a significant component of belowground organic carbon, in nutrient cycling and its impact on the dynamics of microbial communities in subsurface systems remains poorly understood. It is currently unclear whether necromass metabolites from various microbes are different, whether certain groups of metabolites are preferentially utilized over others, or whether different microbial species respond to various necromass metabolites. In this study, we aimed to fill these knowledge gaps by designing enrichments with necromass as the sole nutrient source for subsurface microbial communities. We used the soluble fraction of necromass from bacterial isolates belonging to Arthrobacter, Agrobacterium, and Pseudomonas genera, and our results indicate that metabolite composition of necromass varied slightly across different strains but generally included amino acids, organic acids, and nucleic acid constituents. Arthrobacter-derived necromass appeared more recalcitrant. Necromass metabolites enriched diverse microbial genera, particularly Massilia sp. responded quickly regardless of the necromass source. Despite differences in necromass utilization, microbial community composition converged rapidly over time across the three different necromass amendments. Uracil, xanthine, valine, and phosphate-containing isomers were generally depleted over time, indicating microbial assimilation for maintenance and growth. However, n...