บทคัดย่อPhylloplane yeasts are susceptible to a wide variety of environmental flucations such as urban and industrial air pollution. Surveys of air quality using leaf yeasts as bioindicators have never been carried out in Brazil. By using the spore-fall method, leafyeast populations were surveyed from the phyllosphere of Bauhinia forficate, Tabebuia sp., and Terminalia catappa, wide-spread tree species in urban environments of brazil. Tow cities from sao Paulo state, representing high pollution level (cubatao) and air good quality (aguas de sao pedro), were leaf tree sampled in winter and summer seasons of 2005 and 2006. The results demonstrated lower counts of leafyeast for urban area of cubatao indicating that such yeasts are sensitives to pollutants of the air, specifically to sulphur dioxide of which level reached around 50 ug/m3 in the winter, concentration of which the yeasts respond. Between tree, there was significant difference (p<0.1) for ipe (tabebuiasp.) and chapeu de sol (terminalia catappa) at the winter term for aguas de sao pedro. Air pollution seems to affect leafyeast populations for all tree in the same way. The most common yeast isolated was Sporobolomyces roseus, a ballistosporous basidiomycete species. Other ballistosporous yeasts, colonies of which were typically white, wereinfrequently isolated by the used method (<5%). A small subset of isolates exhibiting variation in colony morphology was identified as aureobasidium pullulans, pseudozyma Antarctica, Cryptococcus albidus, candida guillermondii and candida sp. The data may have validity for other tropical areas where studies should be addressed to the practical use of leafyeasts as bioindicators for monitoring the air quality.
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