Tianjin Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin, China; School of Civil Engineering, Dalian University of Technology, Dalian, China.
Tianjin Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin, China.
Sci Total Environ. 2024 Feb 20;912:168714. doi: 10.1016/j.scitotenv.2023.168714. Epub 2023 Nov 24.
Detachment of fungal spores from growing colonies results in human exposure. Thus far, the distribution of the binding forces of the spores in a fungal unit is unknown, so that precise prediction of the spores detachment is quite challenging. This investigation used centrifugal separation to measure the binding forces of the spores. Aspergillus niger (A. niger) colonies on a culture plate were placed in a centrifuge, the detached spores were counted, and this number was used to obtain the distribution of binding forces. Next, the air-blowing of an A. niger unit was modeled by computational fluid dynamics (CFD). A spore was judged to be detached if the air-imposed drag force was greater than the binding force. For model validation, the predicted spore detachment ratios were compared with the ratios measured in a wind tunnel test. The results revealed that the binding forces of the spores obeyed the log-normal distribution. The binding forces of the distal spores from colonies with a growth age of 66 h ranged from 0 nN to 4.0 nN and had a mean of 0.65 nN. The CFD modeling predicted the detachment ratios of the distal spores with good accuracy.
真菌孢子从生长菌落上脱落会导致人类暴露。到目前为止，真菌单位中孢子的结合力分布尚不清楚，因此准确预测孢子脱落非常具有挑战性。本研究使用离心分离来测量孢子的结合力。将培养板上的黑曲霉（A. niger）菌落放入离心机中，计算脱落的孢子数量，并以此获得结合力的分布情况。接下来，通过计算流体动力学（CFD）模拟黑曲霉单位的吹气。如果空气施加的阻力大于结合力，则判断孢子脱落。为了验证模型，将预测的孢子脱落率与风洞测试中测量的比值进行了比较。结果表明，孢子的结合力服从对数正态分布。生长龄为 66 小时的菌落中远端孢子的结合力范围在 0 nN 到 4.0 nN 之间，平均值为 0.65 nN。CFD 模型预测远端孢子的脱落率具有很好的准确性。
