夏秋季节北京市居家室内微生物多样性的变化特征

室内空气中过高浓度的生物粒子有害人体健康.空气中的微生物通常与灰尘结合在一起，然而目前对家庭室内灰尘微生物多样性及其随季节变化特征的报道较少.本研究在北京市选择1户家庭，在夏季和秋季定期采集灰尘样品，通过高通量测序研究细菌和真菌群落组成及多样性，并分析细菌-真菌的网络互作特征.结果显示，室内灰尘细菌和真菌群落Shannon指数及Chao1指数夏季均显著高于秋季（p<0.05）.此外，室内灰尘细菌群落结构夏季与秋季无显著差异（p>0.05），主要类群为假单胞菌属（Pseudomonas）、考克氏菌属（Kocuria）和芽孢杆菌属（Bacillus）；真菌群落结构夏季与秋季则明显不同（p<0.05），夏季优势类群为曲霉属（Aspergillus）、链格孢属（Alternaria）和裂褶菌属（Schizophyllum），而秋季曲霉属占绝对主导地位.室内灰尘微生物网络互作具有明显的季节特征，夏季微生物互作主要为细菌-细菌，以及细菌-真菌的正相互作用；而秋季微生物互作比夏季更紧密，以细菌-细菌的正相互作用为主.这些结果可为构建健康的居家环境提供参考依据.

Characteristics of microbial diversity in indoor air of Beijing city in summer and autumn

Excessive microbial particles in indoor air exerts negative effects on human health. Airborne microbes often bind with dust, however, microbial diversity in household dust and its changes with seasonal variation have been rarely reported. In this study, we explored the diversity and composition of bacterial and fungal communities, and characteristics of microbial interaction network in settled dust periodically collected in summer and autumn from a household in Beijng city, using the high-throughput sequencing technique. Shannon and Chao1 indices of bacterial and fungal communities in the indoor dust samples in summer were significantly (p<0.05) higher than those in autumn. Furthermore, there was no significant (p>0.05) difference in the bacterial community structure in the indoor dust samples between summer and autumn. The dominant bacterial populations were Pseudomonas, Kocuria and Bacillus in both seasons. By contrast, significant (p<0.05) difference was detected in the fungal community structure in the indoor dust samples between summer and autumn. In summer, fungal community in the indoor dust samples was mostly composed of Aspergillus, Alternaria and Schizophyllum in genera, while in autumn, Aspergillus was the most predominant fungal genera. In addition, there were obvious seasonal characteristics in the microbial interaction network for the indoor dust samples. In summer, the microbial interaction relationships were mainly comprised of positive correlations between bacteria populations, and between bacteria and fungi. Compared with summer, the associations among microbes in autumn became closer, and the microbial interaction network was dominated by positive correlations between bacteria. These findings could provide a theoretical basis for establishing a healthy household environment.