Integrating microbial ecology in bioprocess understanding: the case of gas biofiltration

Abstract

Biofilters are packed-bed bioreactors where contaminants, once transferred from the gas phase to the biofilm, are oxidized by diverse and complex communities of attached microorganisms. Over the last decade, more and more studies aimed at opening the back box of biofiltration by unraveling the biodiversity-ecosystem function relationship. In this review, we report the insights provided by the microbial ecology approach in biofilters and we emphasize the parallels existing with other engineered ecosystems used for wastewater treatment, as they all constitute relevant model ecosystems to explore ecological issues. We considered three characteristic ecological indicators: the density, the diversity, and the structure of the microbial community. Special attention was paid to the temporal and spatial dynamics of each indicator, insofar as it can disclose the potential relationship, or absence of relation, with any operating or functional parameter. We also focused on the impact of disturbance regime on the microbial community structure, in terms of resistance, resilience, and memory. This literature review led to mitigated conclusions in terms of biodiversity-ecosystem function relationship. Depending on the environmental system itself and the way it is investigated, the spatial and temporal dynamics of the microbial community can be either correlated (e.g., spatial stratification) or uncoupled (e.g., temporal instability) to the ecosystem function. This lack of generality shows the limits of current 16S approach in complex ecosystems, where a functional approach may be more suitable.

Abatement of styrene waste gas emission by biofilter and biotrickling filter: comparison of packing materials and inoculation procedures

“…Currently, more interest is aimed at opening the black box of biofiltration by unravelling the biodiversity-ecosystem function relationship (Cabrol and Malhautier 2011). In the case of the removal of styrene, the ability of the genus Pseudomonas for the degradation of this compound under aerobic conditions has been reported.…”

Understanding the anaerobic BTEX removal in continuous-flow bioreactors for ex situ bioremediation purposes

“…It has been proposed that the ecosystem function is mostly influenced by components of the diversity, such as the evenness of the species distribution, the species composition, the positive species interaction (synergism, co-metabolism, syntrophy) and the dynamics of the communities [38]. For example, parameters such as the dynamic of the microbial community and a high initial evenness are considered of vital importance to guarantee functional stability [33].…”

Biological technologies for the treatment of atmospheric pollutants

“…Typically, inocula have been sourced from wastewater treatment plants or existing biofilters and biotrickling filters [75,76]. Activated sludge from wastewater plants is commonly employed because it contains a large variety of rugged organisms with the potential ability to degrade a wide variety of pollutants [77,78].…”