Screening of fungi for chitosan producers, and copper adsorption capacity of fungal chitosan and chitosanaceous materials

Thirty-three fungal strains were screened for chitosan producers. Although chitosan is believed to occur only in Mucorales strains in the class of Zygomycetes, we found that chitosan was extractable from all the 33 strains from the four classes. High level of chitosan was extractable from some non-zygomycetes strains. Absidia glauca(+) was found to be a promising chitosan producer. High level of chitosan can be extracted from some common industrial fungi, implying that it is feasible to produce chitosan from industrial waste mycelia. Fungal chitosan derived from A. glauca(+) showed the highest adsorption capacity for Cu(II). The order of copper adsorption capacity for these chitinous/chitosanaceous materials is: fungal chitosan>alkali-insoluble materials (AIM)>crustacean chitosan>fungal biomass. The Langmuir and Freundlich constants for the Cu(II) adsorption isotherms were determined with Freundlich model providing a better description of the copper adsorption isotherms.