Optimization of Fermentation Medium for Extracellular Lipase Production from Aspergillus niger Using Response Surface Methodology

Table 1

The composition of components and the experimental sequence for the single-factor experiment.

Sequence	Nutrients	Components	Concentration (g/L)
1	Primary carbon sources	Glucose, maltose, sucrose, glycerol, hydrol	15, 20, 25
2	Secondary carbon sources	Corn starch, modified starch, dextrin	8.5, 10, 11.5
3	Nitrogen sources	Soybean meal, yeast extract, beef extract, peptone, sodium nitrate	35, 40, 45
4	Oils	Olive oil, soybean oil, lard oil, peanut oil, sun-flower seed oil	5, 10, 15
5	Inorganic salts	NaH2PO4, K2SO4, CaCO3	0, 1.5, 2.0, 2.5 (for NaH2PO4)
			0, 0.15, 0.2, 0.25 (for K2SO4)
			0, 4, 5, 6 (for CaCO3)

Corn starch hydrolyzate (hydrol), a less expensive nutrient source for industrial medium, contains 50–60 g/L glucose and is rich in trace elements. The value of hydrol was 30, 40, and 50 g/L.
40 g/L soybean meal was supplemented in the analysis of sodium nitrate. The concentration of sodium nitrate was set as 8, 10, and 12 g/L, respectively.