Antimicrobial potentials of crude fractions of polysaccharides of Ganoderma spp.

The present study aimed to screen antimicrobial activity of polysaccharide extracts of Ganoderma on pathogenic microorganisms. Ganoderma spp. were collected from different parts of Mazandaran province, Iran, and identified using keys and morphological characters. From each Ganoderma spp. 4 fractions (I, II, IIIa and IIIb) were prepared and tested using well assay method against the target cultures. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using broth dilution method. Out of 11 species of Ganoderma spp., only fraction IIIa and IIIb obtained from 4 species of namely Ganoderma multicornum, Ganoderma multiplicatum, Ganoderma perzonatum, and Ganoderma stipitatum showed good activity against bacteria and fungi with the 40 mm zone inhibition. Among the target cultures Escherichia coli and Proteus mirabilis were highly susceptible to the extract. MIC value for Polysaccharide fraction III A and III-B of G. multicornum, G. multiplicatum, G. perzonatum and G. stipitatum on selected microorganisms such as Candida albicans , E. coli , and P. mirabilis showed interesting results. The MIC for fraction IIIa and IIIb of G. multicornum when used against E. coli was 64 µg/ml. Similarly, the MBC value of the same fraction against P. mirabilis was 32 and 64 µg/ml, respectively. Moreover, the target cultures were highly resistant to at least two or more antibiotics particularly penicillin. In conclusion, it is apparent from the present study that Ganoderma spp. polysaccharide extracts showed a potent antimicrobial activity; therefore, it could be employed to combat several diseases caused by pathogenic microorganisms and could be used for the development of valuable pharmaceuticals.