AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Characterization of Fungal Fragments
JACOB MENSAH-ATTIPOE, Sampo Saari, Jorma Keskinen, Anniina Salmela, Anna-Maria Veijalainen, Pertti Pasanen, Tiina Reponen, University of Eastern Finland
Abstract Number: 174 Working Group: Bioaerosols
Abstract Particles, intact spores and sub-micrometer size fragments, are released from fungal growth during growth and sporulation. Among these particles, fragments stay longer in air, are easily inhaled and penetrate deep into the respiratory tract having the potential for causing serious adverse health effects. It is, however, unclear whether the fragments originate from fungal growth or from growth materials as a result of fungi decomposing the growth surface. In this study, we measured the concentration and elemental composition of fragments and spores released from different materials.
Particles from three fungal species (Aspergillus versicolor, Cladosporium cladosporioides and Penicillium brevicompactum), grown on agar and gypsum board for 1, 4 and 18 weeks were aerosolized using the Fungal Spore Source Strength Tester (FSSST) at three different air velocities (5, 16 and 27 m/s). Released spores (da > 0.8 micro-meters) and fragments (da < 0.8 micro-meters) were detected and counted using Optical Particle Size Spectrometer (0.3 – 10 micro-meter) and LAS-X II (0.1 - 1 micro-meter), respectively. The morphology and elemental composition of the particles were analyzed using a transmission and scanning electron microscopes (TEM, SEM) coupled with an energy dispersive spectrometer (EDS).
Release of spores and fragments from both agar and gypsum board increased with increasing air velocity. When grown on agar, the highest concentration of spores and fragments were obtained from 1 week old cultures of P. brevicompactum at an air velocity of 27 m/s. However, no clear trends were observed for particles released from gypsum board. Similar elemental compositions were observed between the spores and fragments. The main elements detected in both spores and fragments were carbon and oxygen in abundance with minor detection of sodium, potassium, phosphorus, calcium, magnesium and silicon.
Preliminary results indicate that the fragments are of fungal origin. The amount of fragment released is influenced by air velocity, growth substrate and fungal species.