Effect of Some Ecological Factors on Occurrence of Yeasts in Soil and Sediment from Iraq

Soil is one of the favorable habitat for microorganism. It considered being the home of wide range of them in particularly, bacteria and fungi. Southern Iraq is characterized by a multiplicity of ecosystem, which include desert, agricultural and marine areas, each of which has special composition that differs from the neighboring system, whether in terms of vegetation or various environmental factors. This in diversity, in turn, may lead to microbial diversity that can be used in different biotechnologies. Regarding that little is known about yeast diversity in such habitats, and therefore the current study aims to assess the yeast community in soil and sediments samples from Basrah and Dhi-Qar provinces, Southern Iraq. Thirty-one species belong to 19 genera were encountered. The isolated species consist of 16 species of Ascomycota and 15 species of Basidiomycota. The soil of Basrah and Dhi-Qar support the growth of diverse species belonged to the genera Aureobasidium, Cutaneotrichosporon, Debaryomyces, Filobasidium Geotrichum, Hanseniaspora, Lodderomyces, Meyerozyma, Symmetrospora, Torulaspora, Vishniacozyma, Pichia, Yarrowia, Cystobasidium, Galactomyces, Rhodotorula, Wickerhamomyces, Candida and Naganishia. One hundred and twelve fungal isolates were identified using the conventional methods depending on morphological characteristics. CHROMagar candida was used as differential culture medium. Iodine stain was used to differentiate ascospores and basidiospores. In addition biochemical method represented by VITEK was used as well as molecular identification. This study represents the first report of occurrence of yeast species in soil and surface sediment samples from Basrah and Dhi-Qar provinces, Southern, Iraq, with effect of some ecological factors on isolation yeast from different location.