Antimicrobial properties and cytotoxicity of sulfated (1,3)-β-D-glucan from the mycelium of the mushroom Ganoderma lucidum

Ganoderma lucidum BCCM 31549 has a long established role for its therapeutic activities. In this context, much interest has focused on the possible functions of the (1,3)-β-D-glucan (G) produced by these cultures in a stirred-tank bioreactor and extracted from their underutilized mycelium. In the existing study, we report on the systematic production of G, and its sulfated derivative (GS). The aim of this study was to investigate the G and its GS from G. lucidum in terms of antibacterial properties, and cytotoxicity spectrum against Human-Prostate-Cell (PN2TA) and Human-Caucasian-Histiocytic-Lymphoma (U937). (1)H NMR for both G and GS compounds showed β-glycosidic linkages and structural similarities when compared with two standards (Laminarin and Fucoidan). The existence of characteristic absorptions at 1,170 and 867 cm(-1) in the FTIR for GS demonstrated the successful sulfation of G. Only GS exhibited antimicrobial activity against a varied range of test bacteria of relevance to foodstuffs and human health. Moreover, both G and GS did not show any cytotoxic effects on PN2TA cells, thus helping demonstrate the safety on these polymers. Also, GS shows 40% antiproliferation against cancerous U937 cells at low concentration (60 µg/mL) applied in this study compared to G (10%). Together, this demonstrates that sulfation clearly improved the solubility and therapeutic activities of G. The water-soluble GS demonstrates the potential multi-functional effects of these materials in foodstuffs.