This study presents features of airborne culturable bacteria and fungi from three different sites (Lanzhou; LZ; 1520 m ASL, Lhasa; LS; 3640 m ASL and Qomolangma; ZF; 4276 m ASL) representing urban (LZ and LS) and remote sites (ZF) over the Tibetan Plateau (TP). Total suspended particle (TSP) samples were collected with an air sampler (Laoying 2030, China) on a quartz filter. Community structures of bacteria and fungi were studied and compared among three different locations. The average levels of bacterial load in the outdoor air ranged from approximately 8.03 x 10(1)to 3.25 x 10(2)CFU m(-3)(Colony forming unit per m(3)). However, the average levels of fungal loads ranged from approximately 3.88 x 10(0)to 1.55 x 10(1)CFU m(-3). Bacterial load was one magnitude higher at urban sites LZ (2.06 x 10(2)-3.25 x 10(2)CFU m(-3)) and LS (1.96 x 10(2)-3.23 x 10(2)CFU m(-3)) compared to remote sites ZF (8.03 x 10(1)-9.54 x 10(1)CFU m(-3)). Similarly, the maximum fungal load was observed in LZ (1.02 x 10(1)-1.55 x 10(1)CFU m(-3)) followed by LS (1.03 x 10(1)-1.49 x 10(1)CFU m(-3)) and ZF (3.88 x 10(0)-6.26 x 10(0)CFU m(-3)). However, the maximum microbial concentration was observed on the same day of the month, corresponding to a high dust storm in Lanzhou during the sampling period. The reported isolates were identified by phylogenetic analysis of 16S rRNA genes for bacteria and ITS sequences for fungi amplified from directly extracted DNA. Bacterial isolates were mostly associated withProteobacteria,Eurotiomycetes and Bacillus, whereas fungal isolates were mostlyAspergillusandAlternaria. Overall, this is a pioneer study that provides information about the airborne microbial concentration and composition of three sites over the TP region depending on environmental parameters. This study provided preliminary insight to carry out more advanced and targeted analyses of bioaerosol in the sites presented in the study.

The airborne microbiome is one of the relevant topics in ecology, biogeochemistry, environment, and human health. Bioaerosols are ubiquitous air pollutants that play a vital role in the linking of the ecosystem with the biosphere, atmosphere, climate, and public health. However, the sources, abundance, composition, properties, and atmospheric transport mechanisms of bioaerosols are not clearly understood. To screen the effects of climate change on aerosol microbial composition and its consequences for human health, it is first essential to develop standards that recognize the existing microbial components and how they vary naturally. Bioaerosol particles can be considered an information-rich unit comprising diverse cellular and protein materials emitted by humans, animals, and plants. Hence, no single standard technique can satisfactorily extract the required information about bioaerosols. To account for these issues, metagenomics, mass spectrometry, and biological and chemical analyses can be combined with climatic studies to understand the physical and biological relationships among bioaerosols. This can be achieved by strengthening interdisciplinary teamwork in biology, chemistry, earth science, and life sciences and by sharing knowledge and expertise globally. Thus, the coupled use of various advanced analytical approaches is the ultimate key to opening up the biological treasure that lies in the environment.