# Basic assessment of microbial dynamics in large- and small-scale biofilters

## TL;DR

This study examines how microbial communities in biofilters used for biogas plant exhaust gas treatment vary based on filter material and water content.

## Contribution

The study provides new insights into microbial colonization patterns in biofilters under different operational conditions.

## Key findings

- Large-scale biofilters showed consistent bacterial abundance regardless of material or water content.
- Fungal and yeast abundance in large-scale biofilters was influenced by filter material and water content.
- Small-scale biofilters revealed an acidophilic bacterial community with potential methanotrophs.

## Abstract

•Data on microbial abundance and community composition of biofilters•Biofilters dominated by an acidophilic prokaryotic community•Water content and biofilter material are impacting microbial colonisation

Data on microbial abundance and community composition of biofilters

Biofilters dominated by an acidophilic prokaryotic community

Water content and biofilter material are impacting microbial colonisation

Treating exhaust gas from biogas plants is commonly done using biofilters composed of different filter materials. Immobilized on these filter materials microbes can convert less desirable exhaust gas components into more wanted ones. The evaluation of the performance of those filters based on microbial data is, however, difficult due to a lack in data regarding microbial colonisation of these filter materials. Thus, in the present study microbial abundance and microbial community composition in large- and small-scale biofilters was evaluated using both, cultivation dependent and independent approaches. Large-scale biofilters showed a similar total abundance of bacteria irrespective of the filter material and the water content of the biofilter. In contrast, fungal and yeast abundance was impacted by both, filter material (bark mulch or coconut fibre) and water content. In small scale biofilters (composed of bark mulch) the water content impacted microbial abundance. While a water content of 90% led to a similar development of bacterial and fungal/yeast abundance, 70% water content caused an asynchronous increase in abundance. Analysis of small-scale biofilters revealed an acidotrophic bacterial community including potential methanotrophs.

Image, graphical abstract