1 research outputs found

    Influence of water availability and temperature on estimates of microbial extracellular enzyme activity

    No full text
    19 páginas.- 5 figuras. 2 tablas.- 50 referencias.- Supplemental information for this article can be found online at http://dx.doi.org/10.7717/peerj.10994#supplemental-information.oils are highly heterogeneous and support highly diverse microbial communities. Microbial extracellular enzymes breakdown complex polymers into small assimilable molecules representing the limiting step of soil organic matter mineralization. This process occurs on to soil particles although currently it is typically estimated in laboratory aqueous solutions. Herein, estimates of microbial extracellular enzyme activity were obtained over a broad range of temperatures and water availabilities frequently observed at soil upper layers. A Pseudomonas strain presented optimum extracellular enzyme activities at high water activity whereas a desiccation resistant bacterium (Deinococcus) and a soil thermophilic isolate (Parageobacillus) showed optimum extracellular enzyme activity under dried (i.e., water activities ranging 0.5-0.8) rather that wet conditions. Different unamended soils presented a distinctive response of extracellular enzyme activity as a function of temperature and water availability. This study presents a procedure to obtain realistic estimates of microbial extracellular enzyme activity under natural soil conditions of extreme water availability and temperature. Improving estimates of microbial extracellular enzyme activity contribute to better understand the role of microorganisms in soils.This study was supported by funding through projects from the Spanish Ministry of Economy and Competitiveness (CGL2014-58762-P) and the Regional Government of Andalusia (RNM2529 and BIO288). These projects have been cofunded by FEDER funds. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscriptPeer reviewe
    corecore