This study was conducted for the production potential and optimization of a novel functional alcohol beverage through submerged cultivation of Ganoderma applanatum. The optimization of culture condition and medium for the maximum production of mycelia...
This study was conducted for the production potential and optimization of a novel functional alcohol beverage through submerged cultivation of Ganoderma applanatum. The optimization of culture condition and medium for the maximum production of mycelial growth, exo-polysaccharide and alcohol dehydrogenase activity from the G. applanatum were examined by response surface methodology and mixture experiments design, respectively. Also, alcohol fermentations of wine and beer was performed using G. applanatum mycelium obtained by cultivation under optimum culture condition and medium. A flask cultivation of G. appolanatum with addition of T. matsutake ethanol extract as substrate into liquid media was conducted, and a new process by two-staged substrate addition, which the extracts were added and maintained at end period of cultivation was intended for the effective cultivation. Effect of cultured products on antioxidation and fibrinolytic activity were evaluated by comparing with the submerged culture of G. applanatum without T. matsutake ethanol extract. The obtained results were as follows.
1. Specific activity of alcohol dehydrogenase (ADH) was measured from mycelium cultured of ten genera mushrooms. The orders of ADH specific activity were Phellinus linteus (100.09 U)〉Lentinus edodes (75.56 U)〉Agaricus blazei (67.52 U)〉Cordiceps militaris ~ Ganoderma applanatum (48.64 ~ 48.34 U)〉Inonotus obiliquus (30.29 U)〉Grifola frondosa (26.27 U). Since ADH activity for alcohol brewing of Agaricus blazei, Tricholoma matsutake, Lentinus edodes, Flammulina velutipes, Phellinus linteus, and Pleurotus ostreatus were reported by other researchers, Ganoderma applanatum was selected as an isolate strain except for these six genera mushrooms.
2. From the results of response surface analysis and mixture experiment for the optimum culture condition and medium at flask culture, the composition of optimum medium for submerged culture of G. applanatum were dextrose 19.08 g/L, sucrose 12.72 g/L, yeast 8.80 g/L, peptone 3.54 g/L, casamino acid 5.21 g/L, KH₂PO₄ 2.69 g/L, K₂HPO₄ 5.80 g/L and MgSO₄ 2.91 g/L, and the optimum culture conditions were obtained at agitation speed of 120 rpm, inoculum volume of 5.12%(v/v) and pH of 5.39.
3. Fermentations of wine and beer were performed using mycelium of G. applanatum cultured using optimized culture condition and medium. G. applanatum produced alcohol in both the aerobic and anaerobic conditions. The ability of alcohol production was improved by shaking after standing culture method more than standing or shaking culture alone. However, the production level of alcohol was much lower than hat of typical alcohol fermentation using S. cerevisiae.
4. When T. matsutake ethanol extract (1∼9%, v/v) was added into a medium in submerged cultivation of G. applanatum, addition of T. matsutake ethanol extract in the range of concentration of 3∼9%(v/v) inhibited the mycelial growth of G. applanatum. This inhibition was supposed to be an action of the ethanol and/or antifungal ingredient from T. matsutake extract as substrate. Therefore, we confirmed that the cultivation of G. applanatum in a medium containing high concentration (3%>) of T. matsutake ethanol extract could not be submerged cultured. For that reason, the two-staged addition of T. matsutake ethanol extract, that is, the addition of T. matsutake ethanol extract by changing a addition time of T. matsutake ethanol extract after cultivation of 0 to 5 days without T. matsutake ethanol extract was intended. When T. matsutake ethanol extract was added at logarithmic phase of mycelial growth after cultivation of 5 days, the inhibition of mycelial growth was effectively prevented indicting the possibility of submerged cultivation in high ethanol containing medium.
5. The two-staged addition of T. matsutake ethanol extract, that was T. matsutake ethanol extract of 5% was added into culture fluids of G. applanatum mycelial growth after cultivation of 5 days under optimal medium obtained using mixture experiments design, and then was successively cultivated for 8 days by using response surface methodology. Optimum culture condition was obtained at pH of 5.37, agitation speed of 120 rpm and inoculum of volume 5.65%. and theoretical maximum value obtained using response surface analysis was mycelial dry weight of 8.91 g/L and exo-polysaccharide of 4.99 g/L .
6. The culture broth obtained by using two-staged T. matsutake ethanol extract addition technique was contained ethanol level more than 90% from the original ethanol content. The total phenolic compounds contents from culture broth of G. applanatum of addition T. matsutake ethanol extract were 2∼4 folds higher than those of control (T. matsutake ethanol extract). The culture broth exhibited no fibrinolytic activity. However, the antioxidant activity using DPPH (1,1-diphenyl- 2-picryl hydrazyl) radical scavenging assay was 68∼91%, and these activities were much higher than 27∼57% of T. matsutake ethanol extract alone, indicating a modification effect by this established cultivation method.
Therefore, it was found that the submerged cultivation of G. applanatum using two-staged T. matsutake ethanol extract addition technique would provide a potential method for novel functional alcohol beverages.