Chemical Composition and Bacterial Community in Size-Resolved Cloud Water at the Summit of Mt. Tai, China

Chao Zhu ； Jianmin Chen ； Xinfeng Wang ； Jiarong Li ； Min Wei ； Caihong Xu ； Xianmang Xu ； Aijun Ding ； Jeffrey L. Collett, Jr.

《Aerosol and Air Quality Research》 18卷1期 (2018/01) Pp. 1-14

https://doi.org/10.4209/aaqr.2016.11.0493

摘要

A three-stage collector was used to collect size-resolved cloud samples at the summit of Mt. Tai. Subsequently, analyses of pH values, water-soluble ions, and trace metals were performed and bacterial community were conducted using MiSeq amplicon sequencing. The pH values of the samples decreased as droplet sizes decreased. Sulfate (SO_4^(2-)), nitrate (NO_3^-) and ammonium (NH_4^+) were the main secondary inorganic ions which their concentration distributed significantly different from size-resolved cloud water. The NH_4^+ concentration was higher in smaller droplets. The SO_4^(2-) and NO_3^- concentrations were higher in larger droplets. The Ca^(2+) concentration increased as droplet size increased. Small droplet samples tended to have lower pH value, mainly because of the more acidic (SO_4^(2-) and NO_3^-) and less acid-neutralizing (NH_4^+ and Ca^(2+)) components. The bacterial community in size-resolved cloud samples were firstly recognized and dominated by the genera of Lactococcus (average abundance 34.9%) and Bacillus (average abundance 34.0%). Linear discriminant analysis effect size (LEfSe) revealed differences of the bacterial community in size-resolved cloud water samples, which was probably caused by the bacterial size. Redundancy analysis suggested several minor correlations that the H_2O_2, NO_2^- concentrations, and trace metals exert effects on the bacterial community.

關鍵字

Cloud sample ； Three-stage collector ； Chemical composition ； Bacterial community