Airborne Bacterial Community Composition According to Their Origin in Tenerife, Canary Islands

Abstract

Microorganisms are ubiquitous in the environment, and the atmosphere is no exception. However, airborne bacterial communities are some of the least studied. Increasing our knowledge about these communities and how environmental factors shape them is key to understanding disease outbreaks and transmission routes. We describe airborne bacterial communities at two different sites in Tenerife, La Laguna (urban, 600 m.a.s.l.) and Izaña (high mountain, 2,400 m.a.s.l.), and how they change throughout the year. Illumina MiSeq sequencing was used to target 16S rRNA genes in 293 samples. Results indicated a predominance of Proteobacteria at both sites (>65%), followed by Bacteroidetes, Actinobacteria, and Firmicutes. Gammaproteobacteria were the most frequent within the Proteobacteria phylum during spring and winter, while Alphaproteobacteria dominated in the fall and summer. Within the 519 genera identified, Cellvibrio was the most frequent during spring (35.75%) and winter (30.73%); Limnobacter (24.49%) and Blastomonas (19.88%) dominated in the summer; and Sediminibacterium represented 10.26 and 12.41% of fall and winter samples, respectively. Sphingomonas was also identified in 17.15% of the fall samples. These five genera were more abundant at the high mountain site, while other common airborne bacteria were more frequent at the urban site (Kocuria, Delftia, Mesorhizobium, and Methylobacterium). Diversity values showed different patterns for both sites, with higher values during the cooler seasons in Izaña, whereas the opposite was observed in La Laguna. Regarding wind back trajectories, Tropical air masses were significantly different from African ones at both sites, showing the highest diversity and characterized by genera regularly associated with humans (Pseudomonas, Sphingomonas, and Cloacibacterium), as well as others related to extreme conditions (Alicyclobacillus) or typically associated with animals (Lachnospiraceae). Marine and African air masses were consistent and very similar in their microbial composition. By contrast, European trajectories were dominated by Cellvibrio, Pseudomonas, Pseudoxanthomonas, and Sediminibacterium. These data contribute to our current state of knowledge in the field of atmospheric microbiology. However, future studies are needed to increase our understanding of the influence of different environmental factors on atmospheric microbial dispersion and the potential impact of airborne microorganisms on ecosystems and public health.

Urban Aerobiome and Effects on Human Health: A Systematic Review and Missing Evidence

“…Bowers et al reported the prevalence of Actinobacteria, which are soil bacteria, during the winter-spring period, and Pseudomonadales, a leaves-related microorganism, during the late-spring and summer [16]. In specific insular locations, the airborne bacterial community composition was strictly influenced by the origin of the air masses and by the altitude of the urban site [35].…”

“…Regarding the influence of the season on the microbial abundance and diversity in the urban areas, there are several discordant results. Few studies reported that hot seasons (summer and spring) are associated with higher bacterial abundance [13,16,17,35,39,40,[44][45][46]55]. The seasonal effect is determined by bioaerosol emission source and atmospheric conditions [41].…”

Identification of New <i>Halomonas</i> Strains from Food-related Environments

“…Activated sludge processing facilities for umeboshi factory effluents were located a few kilometers away from the nearest coast. Therefore, the origin of umeboshi isolates may be a nearby ocean ( González-Martín et al , 2021 ). Marine organisms are some of the largest reservoirs of viruses, which may contribute to marine microbial and nutrient homeostasis and gene transfer among marine organisms ( Bergh et al , 1989 ).…”

About the Biodiversity of the Air Microbiome

“…For example, 38 bacterial taxa were identified in the near-surface layers of the troposphere in urban areas [ 41 ]. Most studies demonstrated that Proteobacteria, Firmicutes, and Actinobacteria are the major phyla in the bacterial microbiome of the lower [ 41 , 62 , 63 ] and upper troposphere [ 50 , 64 , 65 ]. Meanwhile, in the lower troposphere in urban areas, Firmicutes can make a significant contribution (20–30%), while such phyla as Cyanobacteria, Bacteroidetes, Chloroflexi, Acidobacteria, and Deinococcus-Thermus are the minor phyla (1–5% of the relative content of nucleotide sequences).…”

“…It is noteworthy that, as opposed to the mycobiome, whose indoor composition depended on its outdoor composition and was independent of people’s activity indoors, the indoor biodiversity of the bacterial microbiome was dependent both on the outdoor bacterial microbiome [ 65 ] and on people’s activity indoors [ 41 ]. However, outdoor air pollution may not affect the biodiversity of bacterial and archaeal ensembles in indoor bioaerosols, as it was shown in a study conducted in Beijing [ 74 ].…”