Table 3.

Effects of organic solvents, metal ions, and surfactants on lipase activity

Effects of lipase activity		Relative activity (%)
Influencing factors	Enzyme activity (U/mg)
Control samples	31.67 ± 0.26	100%
Metal ions
Mn2+	30.29 ± 0.25	95.65
Mg2+	29.88 ± 0.06	94.34
Zn2+	4.18 ± 0.20	13.18
Ca2+	34.00 ± 0.06	107.36
Co2+	3.32 ± 0.04	10.50
Cu2+	3.99 ± 0.31	12.61
Fe2+	0.59 ± 0.07	1.87
Fe3+	1.60 ± 0.06	5.04
Ni2+	12.08 ± 0.08	38.15
EDTA	6.00 ± 0.34	18.94
Organic solvents
Methanol	22.88 ± 0.18	72.24
Ethanol	33.98 ± 0.18	107.29
Isopropanol	15.00 ± 0.01	47.36
n-Butanol	32.60 ± 0.07	102.93
Isopentanol	17.33 ± 0.22	54.71
Benzene	33.98 ± 0.18	72.24
Methylbenzene,	25.74 ± 0.01	81.29
styrene	25.11 ± 0.01	79.28
n-Hexane	37.34 ± 0.14	117.90
n-Heptane	24.21 ± 0.47	76.44
Acetone	26.06 ± 0.02	82.29
Furfural	21.40 ± 0.22	67.57
Surfactants
Triton-100X	49.47 ± 0.56	156.21
Tween 20	1.73 ± 0.01	5.48
Tween 80	5.37	16.95
SDS	3.09 ± 0.43	9.77
Gum arabic	33.72 ± 0.17	106.48
Polyethylene glycol	40.30 ± 0.12	127.26