Mensah-Attipoe Jacob, Reponen Tiina, Veijalainen Anna-Maria, Rintala Helena, Täubel Martin, Rantakokko Panu, Ying Jun, Hyvärinen Anne, Pasanen Pertti
Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland.
Department of Environmental Health, University of Cincinnati, Cincinnati, OH, USA.
Microbiology (Reading). 2016 Nov;162(11):1895-1903. doi: 10.1099/mic.0.000372. Epub 2016 Sep 20.
Fungal growth on indoor surfaces can decay building materials and release hazardous substances that affect indoor air quality. Despite the numerous methods available for growth determination, there is no commonly accepted standard. The goal of this study was to compare five different assay methods for the measurement of fungal growth: cultivation, MS-based determination of ergosterol, beta-N-acetylhexosaminidase activity, quantitative PCR and microscopic spore counting. Three fungal species (Aspergillus puulaauensis, Cladosporium montecillanum and Penicillium polonicum) were grown on three different building materials (two types of acoustic board and wood). Fungal load was determined at different time points. Results from all of the methods, except the spore count, showed good correlation between each other (r=0.6-0.8). Results obtained with the cultivation method had the highest variability among replicate samples (65 %), making it the least reproducible in repeated measurements. However, it also displayed the highest variability in incubation times (149 %), indicating its suitability for detecting transient changes in the physiological state of cells. Similar to the cultivation method, quantitative PCR correlated well with the other methods and had high variability in incubation times but had lower variability among replicate samples. Ergosterol and beta-N-acetylhexosaminidase enzyme activity seemed to be the methods least dependent on the physiological state of the cells. Varying growth dynamics were observed for different species over time with the different assay methods. Each one of the tests provides a different perspective on fungal quantification due to its specific responses to the various stages of fungal growth.
室内表面的真菌生长会使建筑材料腐烂，并释放影响室内空气质量的有害物质。尽管有许多方法可用于测定真菌生长，但尚无普遍接受的标准。本研究的目的是比较五种不同的真菌生长测定方法：培养法、基于质谱的麦角固醇测定法、β-N-乙酰己糖胺酶活性测定法、定量聚合酶链反应（qPCR）和显微镜孢子计数法。三种真菌（普氏曲霉、蒙特西枝孢和波兰青霉）在三种不同的建筑材料（两种吸音板和木材）上生长。在不同时间点测定真菌负荷。除孢子计数外，所有方法的结果相互之间均显示出良好的相关性（r = 0.6 - 0.8）。培养法获得的结果在重复样本中的变异性最高（65%），使其在重复测量中最不可重复。然而，它在孵育时间上也显示出最高的变异性（149%），表明其适用于检测细胞生理状态的瞬时变化。与培养法类似，定量PCR与其他方法相关性良好，孵育时间变异性高，但重复样本间变异性较低。麦角固醇和β-N-乙酰己糖胺酶活性测定法似乎是最不依赖细胞生理状态的方法。随着时间推移，使用不同的测定方法观察到不同物种具有不同的生长动态。由于每种测试对真菌生长的各个阶段有特定反应，因此每种测试都为真菌定量提供了不同的视角。
