Mushrooms have become attractive as functional foods while they represent an untapped source for the development of drugs and nutraceuticals. Comparing with the established field cultivation, their submerged cultivation has significant industrial potential for the effective production of biomass and valuable metabolites [1]. In this study, Ganoderma australe (Fr.) Pat. (strain ATHUM 4345, collected from Greece), which is a species of pharmaceutical interest [2] was investigated for maximum biomass production with enhanced dietary fiber and bioactive β-glucan content in a batch-stirred tank bioreactor. Specifically, when the optimized culture medium was tested in a 20-L stirred tank bioreactor, high biomass yields (10.1±0.4g/L) and productivity of 0.09g L-1h-1 were obtained. The yield coefficients for total glucan and dietary fibers on biomass formed were 94.9±6 and 341.2±12.3mg/g mycelium dry weight, respectively [3]. Additionally, the biomass produced by the process described above, was lyophilized and finally extracted with ethyl acetate:cyclohexane. Subsequently, the fractionation of the resulting extract by chromatographic techniques led to the isolation and identification of linoleic acid, 19-octacosenoic acid, 9-palmitoleic acid, ergosta-5,7,22-trien-3β-ol and a derivative of the triterpene austrolactone. All compounds isolated, were identified by means of spectral data (1H-NMR and 2D NMR), HRMS and direct comparison with the respective literature data. The findings of this study are valuable, as the established fermentation process, led to the efficient production of biomass containing bioactive compounds. Those results demonstrate the potential of producing high added value bioactive compounds from G. australe strain under submerged culture conditions on an industrial scale.