The ice nucleation ability of one of the most abundant types of fungal spores found in the atmosphere

Autor: R. Iannone, D. I. Chernoff, A. Pringle, S. T. Martin, A. K. Bertram
Jazyk: angličtina
Rok vydání: 2011
Předmět:
Zdroj: Atmospheric Chemistry and Physics, Vol 11, Iss 3, Pp 1191-1201 (2011)
Druh dokumentu: article
ISSN: 1680-7316
1680-7324
DOI: 10.5194/acp-11-1191-2011
Popis: Recent atmospheric measurements show that biological particles are a potentially important class of ice nuclei. Types of biological particles that may be good ice nuclei include bacteria, pollen and fungal spores. We studied the ice nucleation properties of water droplets containing fungal spores from the genus Cladosporium, one of the most abundant types of spores found in the atmosphere. For water droplets containing a Cladosporium spore surface area of ~217 μm2 (equivalent to ~5 spores with average diameters of 3.2 μm ), 1% of the droplets froze by −28.5 °C and 10% froze by –30.1 °C. However, there was a strong dependence on freezing temperature with the spore surface area of Cladosporium within a given droplet. Mean freezing temperatures for droplets containing 1–5 spores are expected to be approximately −35.1 ± 2.3 °C (1σ S. D.). Atmospheric ice nucleation on spores of Cladosporium sp., or other spores with similar surface properties, thus do not appear to explain recent atmospheric measurements showing that biological particles participate as atmospheric ice nuclei. The poor ice nucleation ability of Cladosporium sp. may be attributed to the surface which is coated with hydrophobins (a class of hydrophobic proteins that appear to be widespread in filamentous fungi). Given the ubiquity of hydrophobins on spore surfaces, the current study may be applicable to many fungal species of atmospheric importance.
Databáze: Directory of Open Access Journals