We created a handmade 3D-printed air sampler to effectively collect live airborne bacteria, and determined which environmental factors influenced the bacteria. Bacterial colony forming units (CFUs) in the air samples (n = 37) were monitored by recording the environmental changes occurring over time, then determining the presence/absence of correlations among such changes. The bacterial CFUs changed sharply and were significantly correlated with the DNA concentrations, indicating that the captured bacteria made up most of the airborne bacteria. Spearman's rank correlation analysis revealed significant correlations between the bacterial CFU values and some environmental factors (humidity, wind speed, insolation, and 24-h rainfall). Similarly the significant associations of CFU with humidity and wind speed were also found by multiple regression analysis with box-cox transformation. Among our panel of airborne bacteria (952 strains), 70 strains were identified as soil-derived Bacillus via the production of Escherichia coli- and Staphylococcus aureus-growth inhibiting antibiotics and by 16S rDNA typing. Soil-derived protozoa were also isolated from the air samples. We conclude that the airborne bacteria mainly derived from soil can alter in number according to environmental changes. Our sampler, which was created by easy-to-customize 3D printing, is a useful device for understanding the dynamics of live airborne bacteria.

我们创建了一个手工制作的 3D 打印空气采样器来有效地收集空气中的活细菌，并确定哪些环境因素会影响细菌。空气样本中的菌落形成单位 (CFU) ( n = 37) 通过记录随时间发生的环境变化，然后确定这些变化之间相关性的存在/不存在来监测。细菌 CFU 急剧变化并与 DNA 浓度显着相关，表明捕获的细菌构成了大部分空气传播细菌。Spearman 等级相关分析显示细菌 CFU 值与一些环境因素（湿度、风速、日照和 24 小时降雨量）之间存在显着相关性。类似地，CFU 与湿度和风速的显着关联也通过使用 box-cox 变换的多元回归分析发现。在我们的空气传播细菌（952 株）中，有 70 株被鉴定为土壤来源的芽孢杆菌。大肠杆菌和金黄色葡萄球菌的生长抑制抗生素和 16S rDNA 分型。土壤来源的原生动物也从空气样本中分离出来。我们得出结论，主要来自土壤的空气传播细菌的数量会根据环境变化而改变。我们的采样器是通过易于定制的 3D 打印创建的，是了解空气中活细菌动态的有用设备。