Dear Golla Ramanjaneyulu

You will find useful information in the following chapters (all chapters are attached):

(1) Kyria L. and Boundy-Mills (2014) Chapter 2. Methods for the Isolation and Investigation of the Diversity of Cold-Adapted Yeasts and Their Ex Situ. Preservation in Worldwide Collections.

(2) Cletus P. et al (2011) Chapter 7. Methods for Isolation, Phenotypic. Characterization and Maintenance of Yeasts.

(3) Bergman L W (2001) Growth and Maintenance of Yeast

Elsheikh

I use the method of serial dilutions of Madigan.  Basically the method consist in diluting around 10g of soil sample in sterile peptonated water 1% with constant agitation.  Then perform serial dilutions from 10-1 to 10-9, and plate 100uL of the last dilutions 10-7, 10-8 and 10-9 .  I have more success using PDA (Potato Dextrose Agar).  Then select the colonies with the morphology characteristic of yeast (creamy appeareance, straight border and plane grow), perform a gram-stain then re-plate your isolates by sequencial plating and do freezer stocks of the strains.  Then you may want to determine your species.  The method is described in The Biology of Microorganisms.  (Brock)

we use 10-5 dilution for isolation of yeast . but you can go for further dilution.