Community structural differences shape microbial responses to high molecular weight organic matter ...

• Main Authors: Ziervogel, K., Teske, A., Buckley, A., Ghobrial, S., Arnosti, C., Balmonte, J.P., Hoarfrost, A.
• Format: Text
• Language: English
• Published: Blackwell Publishing Ltd 2019
• Subjects: North Atlantic
• Online Access: https://dx.doi.org/10.17615/v47b-3d09; https://cdr.lib.unc.edu/concern/articles/fx719w976

The extent to which differences in microbial community structure result in variations in organic matter (OM) degradation is not well understood. Here, we tested the hypothesis that distinct marine microbial communities from North Atlantic surface and bottom waters would exhibit varying compositional succession and functional shifts in response to the same pool of complex high molecular weight (HMW-OM). We also hypothesized that microbial communities would produce a broader spectrum of enzymes upon exposure to HMW-OM, indicating a greater potential to degrade these compounds than reflected by initial enzymatic activities. Our results show that community succession in amended mesocosms was congruent with cell growth, increased bacterial production and most notably, with substantial shifts in enzymatic activities. In all amended mesocosms, closely related taxa that were initially rare became dominant at time frames during which a broader spectrum of active enzymes were detected compared to initial timepoints, ...