It is shown that the deletion of BGL2 gene leads to increase in chitin content in the cell wall of Saccharomyces cerevisiae. A part of the additional chitin can be removed from the bgl2Delta cell wall by alkali or trypsin treatment. Chitin synthase 1 (Chs1) activity was increased by 60 % in bgl2Delta mutant. No increase in chitin synthase 3 (Chs3) activity in bgl2Delta cells was observed, while they became more sensitive to Nikkomycin Z. The chitin level in the cell walls of a strain lacking both BGL2 and CHS3 genes was higher than that in chs3Delta and lower than that in bgl2Delta strains. Together these data indicate that the deletion of BGL2 results in the accumulation and abnormal incorporation of chitin into the cell wall of S. cerevisiae, and both Chs1 and Chs3 take part in a response to BGL2 deletion in S. cerevisiae cells.