Abundance and Community Structure of Bacteria on Asian Dust Particles Collected in Beijing, China, during the Asian Dust Season

Abstract

Approximately 180 t/km2 of Asian dust particles are estimated to fall annually on Beijing, China, and there is significant concern about the influence of microbes transported by Asian dust events on human health and downwind ecosystems. In this study, we collected Asian dust particles in Beijing, and analyzed the bacterial communities on these particles by culture-independent methods. Bacterial cells on Asian dust particles were visualized first by laser scanning microscopy, which demonstrated that Asian dust particles carry bacterial cells to Beijing. Bacterial abundance, as determined by quantitative polymerase chain reaction (PCR), was 10 8 to 10 9 cells/g, a value about 10 times higher than that in Asian dust source soils. Interseasonal variability of bacterial community structures among Asian dust samples, as compared by terminal restriction fragment length polymorphism (T-RFLP), was low during the Asian dust season. Several viable bacteria, including intestinal bacteria, were found in Asian dust samples by denaturing gradient gel electrophoresis (DGGE). Clone library analysis targeting 16S ribosomal RNA (rRNA) gene sequences demonstrated that bacterial phylogenetic diversity was high in the dust samples, and most of these were environmental bacteria distributed in soil and air. The dominant species in the clone library was Segetibacter aerophilus (Bacteroidetes), which was first isolated from an Asian dust sample collected in Korea. Our results also indicate the possibility of a change in the bacterial community structure during transportation and increases in desiccation-tolerant bacteria such as Firmicutes.

Alterations in the airborne bacterial community during Asian dust events occurring between February and March 2015 in South Korea

“…Consistent with our findings, increased proportions of Firmicutes and Actinobacteria in AD samples have been reported in previous studies193233. The genus Bacillus has been isolated from soil, sediment, or sewage, and produces endospores, which may be present in the newly transported dust particles.…”

Fungi diversity in PM<sub>2. 5</sub> and PM<sub>1</sub> at the summit of Mt. Tai: abundance, size distribution, and seasonal variation

“…To determine the fungal biomass, we performed qPCR (Gao et al, 2017a;Yamaguchi et al, 2016;Lee et al, 2010) using a CFX96 real-time PCR detection system (Bio-Rad, Hercules, CA, USA) in 25 µL reaction mixtures containing 12.5 µL TransStart Green qPCR SuperMix, 1 µL ITS3-KYO2 (5 -GATGAAGAACGYAGYRAA-3 ), 1 µL ITS4 (5 -TCCTCCGCTTATTGATATGC-3 ), 5 µL sample DNA, and 5.5 µL double-distilled H 2 O. The amplification followed a three-step PCR for fungal ITS regions: 40 cycles of denaturation at 95 • C for 30 s, primer annealing at 52 • C for 30 s, and extension at 72 • C for 30 s. A standard curve was created using tenfold dilution series of fungal ITS region plasmids.…”

Exotic airborne bacteria identified in urban resuspended dust by next generation sequencing

“…Deinococci were isolated in an Asian dust downwind area [28]. Species typically isolated from ginseng fields such as Flavosolibacter and Pedobacter ginsengisoli were detected on Asian dust particles collected during the Asian dust season from Beijing, China [29].…”