Coproduction of enzymes and beta-glucan by Aspergillus oryzae using solid-state fermentation of brown rice

Abstract This study aimed to screen a highest hispidin production of strain from 12 strains of Phellinus, and to evaluate the effects of liquid spawn conditions and grain medium on this strain’s hispidin production levels after solid-state fermentation. Results showed that the P. linteus 04 led to the highest hispidin production, this strain was then selected to elucidate the optimal liquid spawn conditions and grain medium for hispidin production. Various liquid spawn conditions were evaluated, and the highest hispidin yield, specific productivity of hispidin, and total content of hispidin were found to be optimal at 1 week of liquid spawn age, cultured with potato dextrose borth, and using 10 % inoculum rate, with each condition resulting to 0.350, 0.325, and 0.328 mg/g dry weight of mycelium, 0.352, 0.251, and 0.249 µg/mg week− 1 specific productivity, 57.90, 60.23, and 61.77 mg/kg dry weight of brown rice medium, respectively. These liquid spawn conditions were then used to determine the appropriate grain medium for hispidin production. The highest hispidin yield and total content of hispidin were observed in pearl barley which resulted in 1.107 mg/g dry weight of mycelium and 199.76 mg/kg dry weight of pearl barley, which led to results that were 4.73-fold and 5.35-fold higher than those of control (brown rice medium). Overall, this study shows that P. linteus hispidin production can be enhanced by solid-state fermentation using optimal liquid spawn conditions and the appropriate grain medium.

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CONVERSÃO DE DAIDZINA E GENISTINA DE SOJA POR β-GLICOSIDASE DE Aspergillus oryzae

Boletim do Centro de Pesquisa de Processamento de Alimentos ◽

10.5380/cep.v22i1.1189 ◽

2004 ◽

Vol 22 (1) ◽

Cited By ~ 2

Author(s):

CLAUDIO LIMA AGUIAR ◽

YONG KUN PARK

Keyword(s):

Solid State ◽

Enzymatic Activity ◽

Aspergillus Oryzae ◽

Solid State Fermentation ◽

Fungal Spores ◽

Product Formation ◽

Soy Flour ◽

Slight Reduction ◽

Total Conversion

Avaliou-se a capacidade de conversão de isoflavonas glicosiladas às suas formas agliconas pelo uso de β- glicosidase de Aspergillus oryzae ATCC 22786. A produção de daidzeína e genisteína foi acompanhada por 96 h de fermentação em estado sólido, usando-se farelo de soja e suspensão de esporos do fungo a 30ºC. Notou-se a conversão de glicosil-isoflavonas após 24 h e redução significativa na sua quantidade, depois de 48 h de fermentação. A atividade enzimática acompanhou a formação de produto até 72 h (0,2 UI/ mL), apresentando leve diminuição em 96 h (0,19 UI/ mL). Após 48 h obteve-se conversão total de daidzina e genistina, com formação de 551,1 e 17,2 µg/g de daidzeína e genisteína, respectivamente. A produção de genisteína, no entanto, mostrou-se significativamente superior em 24 h de fermentação (289,3 µg/g). Concluiuse que a β-glicosidase produzida por Aspergillus oryzae ATCC 22786 foi capaz de converter glicosilisoflavonas em agliconas por fermentação em estado sólido a 30ºC. CONVERSION OF SOY DAIDZEIN AND GENISTEIN BY β -GLUCOSIDASE OF Aspergillus oryzae Abstract The conversion capacity of glucoside isoflavones to aglycones by Aspergillus oryzae ATCC 2786 β-glucosidase was evaluated. The production of daidzein and genistein was observed for 96 h in solid state fermentation, by utilizing soy flour and a suspension of fungal spores at 30ºC. The conversion of glucoside isoflavones was noted after 24 h and a significant reduction in its quantity after 48 h of fermentation. The enzymatic activity followed the product formation until 72 h (0.2 UI/mL), showing a slight reduction in 96 h (0.19 UI/mL). After 48 h total conversion of daidzein and genistein was obtained, with formation of 551.1 and 17.2 µg/g of daidzein and genistein, respectively. The production of genistein, however, was significantly higher in 24 h of fermentation (289.3 µg/g). It was concluded that the produced β-glucosidase by Aspergillus oryzae was capable to convert glucoside isoflavones in to aglycones by solid state fermentation at 30ºC.

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