Optimizing solid-state fermentation for metabolite enrichment by Aspergillus tamarii on rice bran and wheat

Abstract

Globalization has led to an increase in the global population and drug resistance, necessitating the development of novel pharmaceuticals. Fungi represent a promising source for new drugs, producing a diverse array of secondary metabolites, some of which are integral to clinically essential drugs. This study aimed to determine the optimal conditions for enhancing metabolite production by the Indonesian fungal strain Aspergillus tamarii (IPBCC 880066) when cultivated on solid media, specifically rice bran and wheat. The optimal fermentation conditions, including moisture content, growth temperature, and incubation duration, were determined based on the number of spots observed on thin-layer chromatography plates. Results indicated that the optimum conditions for metabolite production were a 40% moisture content, a growth temperature of 25°C, and a 14-day incubation period. Subsequent UPLC-MS/MS analysis identified 22 metabolites produced by A. tamarii on rice bran and 20 metabolites on wheat. Notably, two compounds, N-(2-hydroxypropyl)-2-methylacrylamide and N6-[(benzyloxy)carbonyl]-L-lysine, were detected in both rice bran and wheat fermented by A. tamarii. Some of the identified metabolites have the potential to be applied in the pharmaceutical industry. In conclusion, our study emphasizes A. tamarii’s efficacy in diverse metabolite production under optimized conditions, providing valuable insights for maximizing fungal metabolite production in potential pharmaceutical applications.