Airborne Microbial Communities at High-Altitude and Suburban Sites in Toyama, Japan Suggest a New Perspective for Bioprospecting.

Daisuke Tanaka,Fumito Maruyama,Kazuma Aoki,Akihiro Sakatoku,Motoshi Goto,So Fujiyoshi,Shunsuke Takato,Shogo Nakamura,Takamune Shimada,Kei Sato

doi:10.3389/fbioe.2019.00012

Daisuke Tanaka, Fumito Maruyama + Show 8 more

Open Access

https://doi.org/10.3389/fbioe.2019.00012

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Abstract

Airborne microorganisms, especially those at high altitude, are exposed to hostile conditions, including ultraviolet (UV) radiation, desiccation, and low temperatures. This study was conducted to compare the composition and abundance of airborne microorganisms at a high-altitude site, Mt. Jodo [2,839 m above mean sea level (AMSL)] and a suburban site (23 m AMSL) in Toyama, Japan. To our knowledge, this is the first study to investigate microbial communities in air samples collected simultaneously at two sites in relatively close proximity, from low and high altitude. Air samples were collected over a period of 3 years during 2009–2011. We then examined the bacterial and eukaryotic communities and estimated the abundance of bacteria and fungi with real-time TaqMan PCR. The airborne bacterial and eukaryotic communities differed between high-altitude and suburban sites on each sampling day. Backward trajectory analysis of air masses that arrived at high-altitude and suburban sites on each sampling day displayed almost the same paths. The bacterial communities were dominated by Actinobacteria, Firmicutes, and Proteobacteria, while the eukaryotic communities included Ascomycota, Basidiomycota, and Streptophyta. We also predicted some application of such microbial communities. The airborne bacterial and fungal abundance at the high-altitude site was about two times lower than that at the suburban site. These results showed that each airborne microbial communities have locality even if they are collected close location.

Highlights

Airborne microbes are ubiquitous in the atmosphere, being present at a density of 103–106 cells per cubic meter of air
We previously reported seasonal variations in airborne bacterial community over a 1-year period at a suburban site in Toyama based on PCR-DGGE (Tanaka et al, 2015)
The Toyama sampling sites include a suburban site on the roof of the three-story building of the Faculty of Science, University of Toyama (36◦41′54′′N, 137◦11′13′′E, 23 m above mean sea level, AMSL) and a high-altitude site at the peak of Mt

Summary

Introduction

Airborne microbes are ubiquitous in the atmosphere, being present at a density of 103–106 cells per cubic meter of air. We describe the bacterial and eukaryotic communities in air samples collected simultaneously from high-altitude and suburban sites in Toyama, central Japan, at five time points from September 2009 to September 2011 during late summer to early autumn. Three-day backward trajectories were calculated for air masses arriving at the high-altitude site at 3,000 and 3,500 m and at the suburban site at 500 and 1,000 m (Supplementary Figure 1).

Results

Conclusion