Bacterial degradation of airborne phenol in the phyllosphere

Abstract

Despite the vast surface area of terrestrial plant leaves and the large microbial communities they support, little is known of the ability of leaf-associated microorganisms to access and degrade airborne pollutants. Here, we examined bacterial acquisition and degradation of phenol on leaves by an introduced phenol degrader and by natural phyllosphere communities. Whole-cell gfp-based Pseudomonas fluorescens bioreporter cells detected phenol on leaves that had previously been transiently exposed to gaseous phenol, indicating that leaves accumulated phenol; moreover, they accumulated it in sites that were accessible to epiphytic bacteria and to concentrations that were at least 10-fold higher than those in the air. After inoculated leaves were exposed to gaseous 14C-phenol, leaves harbouring the phenol-degrading Pseudomonas sp. strain CF600 released eight times more 14CO2 than did leaves harbouring a non-degrading mutant, demonstrating that CF600 actively mineralized phenol on leaves. We evaluated phenol degradation by natural microbial communities on green ash leaves that were collected from a field site rich in airborne organic pollutants. We found that significantly more phenol was mineralized by these leaves when the communities were present than by these leaves following surface sterilization. Thus, phenol-degrading organisms were present in these natural communities and were metabolically capable of phenol degradation. Collectively, these results provide the first direct evidence that bacteria on leaves can degrade an organic pollutant from the air, and indicate that bacteria on leaves could potentially contribute to the natural attenuation of organic air pollutants.

Linking environmental heterogeneity and reproductive success at single-cell resolution

“…Temporal and spatial variation in single-cell green fluorescence indicated substantial heterogeneity in the availability of fructose to individual leaf colonizers (Leveau and Lindow, 2001a). Such heterogeneity has also been reported for other nutrients or stimuli that leaf bacteria are exposed to, including iron (Joyner and Lindow, 2000), water (Axtell and Beattie, 2002), UV light (Gunasekera and Sundin, 2006) and phenolic compounds (Sandhu et al, 2007).…”

Aerobic Degradation of 4-Monobrominated Diphenyl Ether: Identifying and Characterizing Three Strains Isolated from Populus tomentosa Phyllosphere

“…The existing state of bromominated biphenyl ethers in air can be gaseous or adherency to fine particulate matters, and both can migrate for long distances [45][46][47]. It has been reported that gaseous pollutants are prone to accumulate on the leaf surface, several to dozens of times higher than in the air, which is favorable to be accessible to and degraded by microbial epiphytes [33]. But the degradation experiment conducted in this paper was in the aqueous phase, so the degrading strain was symmetrical, which is different from the bacterial aggregates in phyllosphere aboriginality [48].…”

“…The density of microorganisms residing on the phyllosphere (microbial epiphytes) is enormous, averaging 10 6 -10 7 bacteria per square cm on leaf surface, and the species are various [27][28][29][30]. In recent years, studies about microbial epiphytes removing gaseous chemical compounds including toluene, ethylbenzene, xylene, and phenol have become available [31][32][33][34].…”

Biofilms on the surface of gravels and aquatic plants in rivers and lakes with reusing reclaimed water

“…The test processes were as follows (Xing et al 2005): (1) microbial genomic DNA was extracted by chemical cleavage method after slight modifications, and the genomic DNA directly extracted from bacterial samples was purified according to previous descriptions (Sandhu et al 2007). (2) The genomic DNA was purified using glass bead DNA gel extraction kit according to the manufacture's instructions (product number: SK111, Shanghai Sangon).…”