Changes in hyphal morphology due to chitosan treatment in some fungal species

In this work, changes in the hyphal morphology due to chitosan treatment in some fungal species were studied. Scanning electron microscope (SEM) observations revealed that chitosans with molar fraction of acetyi groups (F sub(A) 0.16 and 0.18) and degree of polymerization (DP 1,089 and 1,242) had a direct effect on the morphology of the chitosan-treated fungi, reflecting its potential for causing a delay in the growth of Alternaria alternata (500 mu g x mL super(-1)), Botrytis cinerea (1,000 mu g x mL super(-1)), Penicillium expansum (1,000 mu g x mL super(-1)) and Rhizopus stolonifer (500 mu g x mL super(-1)). Mycelial aggregation and structural changes such as excessive branching, swelling of the cell wall and hyphae size reduction were observed in the micrographs.