Chitosan is obtained by chemical conversion of chitin, which is a constituent of the exoskeleton of crustacea and insects. An alternative source of chitosan is the cell wall of fungi. Fungal culture media and fermentation condition can, be manipulated to provide chitosan of more consistent physico-chemical properties compared to that derived chemically from chitin. Chitosan has been isolated from Mucor rouxii cultured in three different media, viz., molasses salt medium (MSM), potato dextrose broth (PDB) and yeast extract peptone glucose (YPG) medium under submerged condition and their yield has been found to be the almost same, being 0.61 g/l for MSM, 0.51 g/l for PDB and 0.56 g/l for YPG respectively. Their physico-chemical properties such as ash, moisture, protein contents and specific rotation do not show much difference. However, variation has been observed in their polydispersed nature and crystallinity. Chitosan from MSM was less polydispersed and more crystalline compared to those from YPG and PDB. (C) 2004 Elsevier Ltd. All rights reserved.