Evaluation of Ganoderma lucidum strains for the production of bioactive components and their potential use as antimicrobial agents

In the present study, mycelial biomass of Ganoderma lucidum strains was produced in mushroom complete media under optimized culture conditions of temperature, pH, agitation and the fruiting bodies were raised on wheat straw supplemented with 5 per cent rice bran. Maximum biomass (16.39 mg ml-1) was recorded in strain GL-3 and minimum (10.99 mg ml-1) was observed in strain GL-1 after 28 days of incubation period. Maximum biological efficiency of 13.1 per cent was obtained in 57 days in GL-2 strain. Moreover, weight of fruiting bodies was highest (91 g bag-1) in 5 per cent wheat bran supplemented bags in strain GL-2. Polysaccharides were extracted, characterized and analysed. The maximum yield of polysaccharides was obtained from fruiting bodies (30.06- 63.70%), followed by mycelial biomass (7.61- 21.32%) and culture filtrates (0.86- 2.86%). Non-reducing sugars were the main fraction of sugars which constituted 69.82- 70.39 per cent in fruiting body extracted polysaccharides, 62.08- 83.39 per cent in biomass and 59.75- 77.54 per cent in crude extracts. The extracts from fruiting bodies and biomass of G. lucidum strains also exhibited antibacterial effect against some pathogenic bacteria, Staphylococcus sp. and Enterobacter sp. The present study clearly indicated that variations existed among G. lucidum strains with respect to the production of bioactive molecules, yield and antimicrobial activity. Bioactive components from G. lucidum strains are promising antimicrobial agents that can be harnessed as potent antimicrobial toxicant.