Yeast cell wall consists of ß(1 3) D glucan, ß(1 6) D glucan, chitin, mannan and proteins. Mannan oligosaccharide (MOS) is a glucomannoprotein complex which can effectively bind and adsorb fimbriae of various pathogenic bacteria and thus block their colonization in the gastro intestinal tract, thereby reducing infection. In this research paper, the growth characteristics of yeast were studied on different growth media and alkali soluble mannan was extracted from yeast cell wall. The MOS carbohydrate content was found to be the highest when the culture was grown on YM media. Characterization of mannan was done using TLC and FTIR. IR spectra analysis confirmed the presence of (CH) and (CO) stretching vibrations and presence of (OH) band.