Journal of Pure and Applied MicrobiologyVol. 3 No. 2

Isolation and Characterization of Fungal Chitosan from Malaysian Isolates

K. Nadarajah* and T.Y.W. Cheng

School of Biosciences and Biotechnology, Faculty of Science and Technology Universiti Kebangsaan Malaysia, UKM Bangi 43600 Selangor Darul Ehsan, Malaysia.

Received on 12 June 2009 and accepted on 29 July 2009

 

ABSTRACT

Chitosan from Cunninghamella sp. A1, Absidia butleri 2A1, Rhizopus sp UKM21 and Mucor sp UKM13 was isolated and characterized in this study. The effect of medium and nitrogen sources on the yield of chitosan was investigated. The amount of chitosan produced by these isolates was higher than previously reported, with Cunninghamella sp. A1, Absidia butleri 2A1, Rhizopus sp UKM21 and Mucor sp UKM13 producing 2.59 0.5, 2.20 0.25, 2.05 0.30 and 1.96 0.4 g/L chitosan respectively. The highest yield was obtained in Yeast-Peptone-Glucose (YPG) medium supplemented with peptone (range 0.82 - 2.92 g/L). In addition to affecting yield, these parameters influenced the degree of deacetylation (DD) and molecular weight (MW) of the fungal chitosan. The DD and MW for the fungal chitosan isolated in this study was between 80 - 95% and 5.1 - 35.9 x 104 Dalton respectively. Since the chitosan isolated had high DD and LMW, we tested its ability as an antimicrobial agent. The disc diffusion and Minimum Inhibitory Concentration (MIC) studies indicate that the fungal chitosan had higher inhibitory effects on Gram positive bacteria compared to the Gram negative organisms tested in this study. The fungal chitosan also showed bacteriocidal effects on Candida spp.

Keywords : chitosan, fungal, antimicrobial, bacteriocidal, degree deacetylation (DD), molecular weight (MW).