บทคัดย่อ Phylloplane yeasts are susceptible to a wide variety of environmental fluctuations 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 forficata, Tabebuia sp., and Terminalia catappa, wide-spread tree species in urban environments of brazil. Two 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 veasts 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 trees, there was significant difference (p<0.1) for ipe (tabebuia sp.) and chapeu de sol (Treminalia catappa) at the winter term for Aguas de Sao Pedro. Air pollution seems to affect leafyeast populations for all trees 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, were infrequently 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.
การแปล กรุณารอสักครู่..
