Bati Butter as a Potential Substrate for Lipase Production by Aspergillus terreus NRRL-255

Abstract

This study evaluated bati butter (Ouratea parviflora) as a substrate for lipase production by solid-state fermentation (SSF) using Aspergillus terreus NRRL-255. A gas chromatograph with a flame ionization detector determined the bati butter fatty acid profile. Lipase production and spore count were optimized using a 3² experimental design and evaluated using the response surface methodology. Moreover, the crude enzyme extract was evaluated against different pH, temperature, and activating and inhibitors reagents. Regarding the fatty acids identified, long-chain accounted for 78.60% of the total lipids. The highest lipase production was obtained at 35 °C and 120 h of fermentation, yielding 216.9 U g^-1. Crude enzyme extract presented more significant activity at 37 °C and pH 9. β-Mercaptoethanol increased the enzyme activity (113.80%), while sodium dodecyl sulfate inactivated the enzyme. Therefore, bati butter proved to be a potential substrate capable of inducing lipase production by solid-state fermentation.

Keywords: Ouratea parviflora; enzyme; experimental design; solid-state fermentation.

Figure 1

Response surface of the variables temperature and fermentation time on the response of enzyme activity (A) and spore count (B).

Figure 2

Effect of temperature on the enzyme activity of lipase. *** Significantly different values of control (37 °C), according to ANOVA followed by Dunnett’s post hoc test (p < 0.0001). Mean and standard deviation.

Figure 3

Effect of pH on lipase activity. ** Values significantly different from control (pH 8), according to ANOVA followed by Dunnett’s post hoc test (p < 0.001). *** Values significantly different from control (pH 8), according to ANOVA followed by Dunnett’s post hoc test (p < 0.0001). Mean and standard deviation.