Plant root microbiome. rhizosphere metagenome

Due to the long durations spent inside by many humans, indoor air quality has become a growing concern. Biofiltration has emerged as a potential mechanism to clean the indoor air of harmful volatile organic compounds (VOCs), which are usually at higher concentrations indoors than outdoors. Root-associated microbes are thought to drive the functioning of plant-based biofilters, or “biowalls”, converting VOCs into biomass, energy, and carbon dioxide. But little is known about the root communities of such artificially grown plants, how or whether they differ from those grown in soil, and whether any changes in composition are driven by VOCs. In this study, we investigate how bacterial communities on biofilter plant roots change over time and in response to VOC exposure. Through analyses of 16S rRNA amplicon sequence libraries, we compare root communities from soil-grown plants versus those from two biowalls, while also comparing communities from roots exposed to clean- versus VOC-laden- air in a laboratory biofiltration system. Results show differences in bacterial communities between soil- versus biowall-grown plants, and between those from between clean air versus VOC exposed plant roots. Biowall-grown and VOC-exposed roots both harbored enriched levels of bacteria from the genus Hyphomicrobium. Given their known capacities to break down aromatic and halogenated compounds, we hypothesize these bacteria to be important VOC-degraders. While different strains of Hyphomicrobium proliferated in the two studied biowalls and our lab experiment, strains were shared across plant species suggesting that a wide range of ornamental houseplants harbor similar microbes of potential use in living biofilters.