Asian dust-transported bacteria survive in seawater and alter the community structures of coastal bacterioplankton in the Yellow Sea

Dust aerosol deposition can affect marine bacterioplankton community composition and function by supplying nutrients and airborne microbes. However, few studies have determined direct microbial responses to dusttransported microbes. In this study, the viability and effects of bacteria transported by Asian dust aerosols on marine bacterioplankton were assessed in the absence of feeding and competitive pressure on the Yellow Sea coast. The abundance of dust-transported bacteria increased twofold within 24 h in sterile seawater, and the bacteria utilized inorganic nitrogen for growth during incubation. Alphaproteobacteria (Rhodobacteraceae and Paracoccus) were the primary surviving bacterial phylotypes, followed by Bacilli (Planococcaceae, Bacillaceae, and Dieziaceae). Moreover, bioavailable nutrients released from dust aerosols resulted in a 2.22-fold increase in the abundance of bacterioplankton, but the promotion effect was inhibited when dust-transported bacteria appeared, which can also shift the bacterial community structure and decrease marine bacterial population diversity. The Rhodobacteraceae phylotypes changed from the prevailing Planktomarina to unclassified Rhodobacteraceae, which accounted for as much as half of the total bacterial abundance in the "live" dust group. Aurantivirga, which belongs to Flavobacteriaceae, also increased but had a lower abundance than the "dead" dust group. These results suggest that airborne microbes transported by dust aerosol deposition are a nonnegligible biological source, even in marginal seas, and their interaction with marine microorganisms will affect the microbial food web and the biogeochemical cycle of oceans.