Spores of puffball fungus Lycoperdon pyriforme as a reference standard of stable monodisperse aerosol for calibration of optical instruments

Abstract

Advanced air quality control requires real-time monitoring of particulate matter size and concentration, which can only be done using optical instruments. However, such techniques need regular calibration with reference samples. In this study, we suggest that puffball fungus (Lycoperdon pyriforme) spores can be utilized as a reference standard having a monodisperse size distribution. We compare the Lycoperdon pyriforme spores with the other commonly used reference samples, such as Al2O3 powder and polystyrene latex (PSL) microspheres. Here we demonstrate that the puffball spores do not coagulate and, thus, maintain the same particle size in the aerosol state for at least 15 minutes, which is enough for instrument calibration. Moreover, the puffball mushrooms can be stored for several years and no agglomeration of the spores occurs. They are also much cheaper than other calibration samples and no additional devices are needed for aerosol generation since the fungal fruiting body acts as an atomizer itself. The aforementioned features make the fungal spores a highly promising substance for calibration and validation of particle size analyzers, which outperforms the existing, artificially produced particles for aerosol sampling. Furthermore, the L. pyriforme spores are convenient for basic research and development of new optical measurement techniques, taking into account their uniform particle size and absent coagulation in the aerosol.

Bioaerosol vertical fungal spores profile in Minas Gerais State, Brazil

“…Some puffball species have shown to maintain structural characteristics for long periods under controlled dry conditions (up to 2 years) (Zhirnov et al, 2019). Since each fruiting body may release trillions of spores as an explosive discharge (Zhirnov et al, 2019), this characteristic reinforces the explanation of the results in the whole boundary layer, including altitudes as high as 350 m. In a similar way, the ascospore Chaetomium sp. (average spore size c.10 µm; Wang et al, 2016) has its spores released from the perithecium after being disturbed with a raindrop.…”

“…Although puffballs belong to an extensive group, the average spore size across the group is 5 µm, and the cloud of spores released from a fruiting body occurs in response to raindrops (Amador et al, 2012) or other types of impacts. Some puffball species have shown to maintain structural characteristics for long periods under controlled dry conditions (up to 2 years) (Zhirnov et al, 2019). Since each fruiting body may release trillions of spores as an explosive discharge (Zhirnov et al, 2019), this characteristic reinforces the explanation of the results in the whole boundary layer, including altitudes as high as 350 m. In a similar way, the ascospore Chaetomium sp.…”