Optimization of Biomass Cultivation from <i>Tuber borchii</i> and Effect of Additives on Triterpenoid Production

Abstract

Edible fungi are renowned for producing biologically active secondary metabolites that possess anti-tumor activity, protect the liver and have other benefits. The cultivation of truffle mycelia through submerged fermentation has gained interest in the production of metabolites for bio-medicinal purposes. In the present study, Tuber borchii was cultivated by submerged fermentation to produce both biomass and triterpenoids. Various additives, including palmitic acid, stearic acid, linoleic acid, chitosan, CaCl2 and limonene, were investigated to enhance triterpenoid production. It was observed that increasing the medium’s linoleic acid concentration to 1 g/L increased the production of triterpenoids to 129.29 ± 6.5 mg/L, which was 2.94 times higher than the control. A number of variables, including potassium and magnesium ion concentrations and carbon and nitrogen sources and concentrations, were considered to ascertain the ideal conditions for T. borchii growth in submerged fermentation. The best concentrations for glucose, yeast extract, peptone, malt extract, KH2PO4 and MgSO4·7H2O in submerged fermentation were 19.45, 4.58, 7.91, 5.3, 0.58 and 0.82 g/L, respectively, according to response surface methodology. Validation analysis revealed that the experimental values and the predicted values were in good agreement. Under ideal circumstances, the maximum dry cell weight (2.980.18 g/L), which was 1.39 times greater than the control, was attained. Finally, the addition of 1.5 g/L linoleic acid on day 14 to the optimal medium elevated the triterpenoid production to 212.63 ± 16.58 mg/L, which was a 4.84-fold increase compared to the control.

Keywords

• <i>Tuber borchii</i>
• triterpenoids
• submerged fermentation
• linoleic acid
• response surface methodology