Effect of Solid-State Fermented Brown Rice Extracts on 3T3-L1 Adipocyte Differentiation.

Aspergillus oryzae KCCM 11372 was used to enhance the production of ß-glucan using humidity control strategies. Under conditions of 60% humidity, solid-state fermentation (SSF) increased the yields of enzymes (amylase and protease), fungal biomass (ergosterol), and ß-glucan. The maximum concentrations obtained were 14800.58 U/g at 72 h, 1068.14 U/g at 120 h, 1.42 mg/g at 72 h, and 12.0% (w/w) at 72 h, respectively. Moreover, the ß-glucan containing fermented brown rice (ß-glucan-FBR) extracts at concentrations of 25-300 µg/ml was considered noncytotoxic to 3T3-L1 preadipocytes. We then studied the inhibitory effects of the extracts on fat droplet formation in 3T3-L1 cells. As a result, 300 µg/ml of ß-glucan-FBR extracts showed a high inhibition of 38.88% in lipid accumulation. Further, these extracts inhibited adipogenesis in the 3T3-L1 adipocytes by decreasing the expression of C/EBPα, PPARγ, aP2, and GLUT4 genes.

Coproduction of Enzymes and Beta-Glucan by Aspergillus oryzae Using Solid-State Fermentation of Brown Rice.

The effect of medium composition on enzyme and ß-glucan production by Aspergillus oryzae KCCM 12698 was investigated. Brown rice, rice bran, nitrogen, and ascorbic acid are key components of the synthetic medium used in liquid-state fermentation. To determine the optimal concentrations of these components for enzyme and ß-glucan production, we conducted one factor at a time experiments, which showed that the optimal concentrations were 30 g/l brown rice, 30 g/l rice bran, 10 g/l soytone, and 3 g/l ascorbic acid. Pretreatment of brown rice for 60 min prior to inoculation enhanced fungal biomass, while increasing the production of enzymes and ß-glucan using solidstate fermentation. Maximum fungal biomass of 0.76 mg/g, amylase (26,551.03 U/g), protease (1,340.50 U/g), and ß-glucan at 9.34% (w/w) were obtained during fermentation. Therefore, solidstate fermentation of brown rice is a process that could enhance yield and overall production of enzymes and ß-glucan for use in various applications.