Abstract:
Oleaginous yeast, Naganishia cerealis IN1S2.5, which had oil content 24.79% (g/g dry cell weight) when grown in synthetic high C/N ratio medium was screened from 39 yeasts isolated from collected samples at Doi Inthanon National Park, Chiang Mai province. Oil palm empty fruit bunch (OPEFB) was evaluated as feedstock for the N. cerealis IN1S2.5 oil production and potential application of the oils was investigated. It was found that the OPEFB liberated the highest glucose (16.67 g/L) when it was pretreated by impregnating in 2 M NaOH (16 h) then steam explosion at 200°C, 200 psi for 5 min while suspending in 2.4% (w/v) NaOH and hydrolysed by cellulase (6 h). The N. cerealis IN1S2.5 grown in the OPEFB hydrolysate (OPEFBH) supplemented with glucose 75 g/L, KH2PO4 4 g/L, CaCl2-2H2O 0.05 g/L and ZnSO4-7H2O 0.02 g/L at pH 4 gave maximum oil yield 2.46 g/L. Predicted properties of produced biodiesel indicated the potential of the N. cerealis IN1S2.5 oil as a biodiesel feedstock. Additionally, the OPEFBH was evaluated as feedstock for palmitoleic acid production by oleaginous yeast Cyberlindnera subsufficiens NG8.2. Cultivation of the Cy. subsufficiens NG8.2 in the OPEFBH mixed with cassava starch hydrolysate (OPEFBH-CSH) to increase sugar concentration of the OPEFBH resulted in higher palmitoleic acid content oils than cultivation in the OPEFBH which its sugar concentration was increased by mixing with glucose solution. Supplementation of the OPEFBH-CSH with KH2PO4 1.0 g/L, MgSO4-7H2O 0.05 g/L and CaCl2-2H2O 0.01 g/L (pH 5.0) increased the oil yield to 1.96 g/L. Reduction of incubation temperature from 30°C to 25°C increased palmitoleic acid content of the oil from 18.03% (g/g) to 21.49% (g/g) without any effect on oil yield and oil composition.
Abstract:
Oleaginous yeast, Naganishia cerealis IN1S2.5, which had oil content 24.79% (g/g dry cell weight) when grown in synthetic high C/N ratio medium was screened from 39 yeasts isolated from collected samples at Doi Inthanon National Park, Chiang Mai province. Oil palm empty fruit bunch (OPEFB) was evaluated as feedstock for the N. cerealis IN1S2.5 oil production and potential application of the oils was investigated. It was found that the OPEFB liberated the highest glucose (16.67 g/L) when it was pretreated by impregnating in 2 M NaOH (16 h) then steam explosion at 200°C, 200 psi for 5 min while suspending in 2.4% (w/v) NaOH and hydrolysed by cellulase (6 h). The N. cerealis IN1S2.5 grown in the OPEFB hydrolysate (OPEFBH) supplemented with glucose 75 g/L, KH2PO4 4 g/L, CaCl2-2H2O 0.05 g/L and ZnSO4-7H2O 0.02 g/L at pH 4 gave maximum oil yield 2.46 g/L. Predicted properties of produced biodiesel indicated the potential of the N. cerealis IN1S2.5 oil as a biodiesel feedstock. Additionally, the OPEFBH was evaluated as feedstock for palmitoleic acid production by oleaginous yeast Cyberlindnera subsufficiens NG8.2. Cultivation of the Cy. subsufficiens NG8.2 in the OPEFBH mixed with cassava starch hydrolysate (OPEFBH-CSH) to increase sugar concentration of the OPEFBH resulted in higher palmitoleic acid content oils than cultivation in the OPEFBH which its sugar concentration was increased by mixing with glucose solution. Supplementation of the OPEFBH-CSH with KH2PO4 1.0 g/L, MgSO4-7H2O 0.05 g/L and CaCl2-2H2O 0.01 g/L (pH 5.0) increased the oil yield to 1.96 g/L. Reduction of incubation temperature from 30°C to 25°C increased palmitoleic acid content of the oil from 18.03% (g/g) to 21.49% (g/g) without any effect on oil yield and oil composition.