Formatted Title
The Centrality of Physical Spaces to Sustained, Abundant Microbial Populations in Bioremediation
Background/Objectives
It is commonly thought that if one can identify a microbe, usually a bacterium, which degrades a contaminant of interest, then simply introducing that microbe into the subsurface will result in site remediation. But bacteria are biological creatures that have their own needs. Some metabolic needs are acknowledged and, to some degree, catered to in biostimulation efforts. Typically, these efforts supply nutrients, sources of nitrogen, and electron acceptors as appropriate. But these efforts need to consider that the subsurface is already inhabited. Physical needs must also be met to establish a new sustainable microbial community by bioaugmentation or if the existing population is expanded. This presentation will demonstrate that physical space conducive to exchanging metabolic products, protecting from predation, segregating incompatible species, and building communities are indispensable.
Approach/Activities
Key elements from the peer-reviewed literature, laboratory experiments, and field samples are presented. Images from confocal microscopy, scanning electron microscopy, and brightfield microscopes will be used to demonstrate microbial abundance and location preferences. Genome and 16S sequencing are used to characterize changes in microbial populations. Functional assays demonstrate changes in activity due to changes in physical habitat.
Results/Lessons Learned
The audience will understand that a successful, sustainable effort at bioremediation requires that microbes be accommodated with the appropriate spaces necessary to live. They will appreciate that most soil and aquifer materials have a limited capacity to support microbial abundance significantly greater than that found before intervention by biostimulation and bioaugmentation. They will see that the failure to provide physical space that meets the needs of the microbial population they hope to sustain will result in low abundance, poor performance, and the need for ongoing intervention.