Microbial degradation and assimilation of veratric acid in oxic and anoxic groundwaters

Frontiers in Microbiology

Microbiology

Kirsten Küsel¹  Susan Trumbore²  Valérie F. Schwab²  Cassandre Sara Lazar³  Nico Ueberschaar⁴  Georg Pohnert⁴ 

[1] Aquatic Geomicrobiology, Institute of Ecology, Friedrich Schiller University Jena, Jena, Germany;German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany;Department Biogeochemical Processes, Max Planck Institute for Biogeochemistry, Jena, Germany;Department of Biological Sciences, University of Quebec at Montreal (UQAM), Montreal, QC, Canada;Aquatic Geomicrobiology, Institute of Ecology, Friedrich Schiller University Jena, Jena, Germany;Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Jena, Germany;

关键词: groundwater;    heterotroph;    assimilation;    degradation;    SIP;    PLFA;   

DOI  :  10.3389/fmicb.2023.1252498

 received in 2023-07-03, accepted in 2023-09-20,  发布年份 2023

来源: Frontiers

【 摘 要 】

Microbial communities are key players in groundwater ecosystems. In this dark environment, heterotrophic microbes rely on biomass produced by the activity of lithoautotrophs or on the degradation of organic matter seeping from the surface. Most studies on bacterial diversity in groundwater habitats are based on 16S gene sequencing and full genome reconstructions showing potential metabolic pathways used in these habitats. However, molecular-based studies do not allow for the assessment of population dynamics over time or the assimilation of specific compounds and their biochemical transformation by microbial communities. Therefore, in this study, we combined DNA-, phospholipid fatty acid-, and metabolomic-stable isotope probing to target and identify heterotrophic bacteria in the groundwater setting of the Hainich Critical Zone Exploratory (CZE), focusing on 2 aquifers with different physico-chemical conditions (oxic and anoxic). We incubated groundwater from 4 different wells using either 13C-labeled veratric acid (a lignin-derived compound) (single labeling) or a combination of 13CO2 and D-labeled veratric acid (dual labeling). Our results show that heterotrophic activities dominate all groundwater sites. We identified bacteria with the potential to break down veratric acid (Sphingobium or Microbacterium). We observed differences in heterotrophic activities between the oxic and anoxic aquifers, indicating local adaptations of bacterial populations. The dual labeling experiments suggested that the serine pathway is an important carbon assimilation pathway and that organic matter was an important source of hydrogen in the newly produced lipids. These experiments also yielded different labeled taxa compared to the single labeling experiments, showing that there exists a complex interaction network in the groundwater habitats.

【 授权许可】

Unknown   
Copyright © 2023 Lazar, Schwab, Ueberschaar, Pohnert, Trumbore and Küsel.