Methods for visualising active microbial benzene degraders in in situ microcosms

Area of Science:

• Environmental Microbiology
• Bioremediation Technologies
• Analytical Chemistry

Background:

• Natural attenuation offers a cost-effective bioremediation strategy for contaminated sites.
• Understanding in situ microbial activity is crucial for assessing natural attenuation effectiveness.
• Current methods struggle to link microbial degradation activity with spatial distribution.

Purpose of the Study:

• To develop and validate a method for visualizing contaminant-degrading microbes in situ.
• To link microbial activity to the spatial distribution of contaminant degraders.
• To assess the efficacy of NanoSIMS for analyzing complex environmental samples.

Main Methods:

• Utilized the direct-push bacterial trap (DP-BACTRAP) in situ microcosm approach.
• Amended sterile microcosms with (13)C-labelled benzene as a microbial substrate.
• Analyzed field-incubated samples using NanoSIMS, SEM, and fluorescence microscopy.

Main Results:

• Successfully visualized benzene-degrading microbes on high surface area materials using NanoSIMS.
• Demonstrated the feasibility of NanoSIMS for analyzing unembedded porous media with complex topography.
• Provided direct visualization of microbial colonization and activity within the microcosms.

Conclusions:

• The combined DP-BACTRAP and NanoSIMS approach is effective for visualizing in situ microbial degradation.
• This method advances the understanding of microbial processes in contaminated environments.
• The technique holds promise for improving bioremediation strategies and site assessments.