Skip to main content
. 2016 Feb 18;15:41. doi: 10.1186/s12934-016-0435-5

Table 4.

Effects of organic solvents on EST4 activity

Organic solvents log P a Residual activity (%)b at concentration (%, v/v) of
20 50 100
Control 100.0 ± 2.1 100.0 ± 3.8 100.0 ± 0.5
DMSO −1.3 82.8 ± 1.7 61.7 ± 8.6 0.6 ± 1.5
DMF −1.0 92.1 ± 2.5 19.4 ± 4.2 5.8 ± 2.0
Methanol −0.76 90.6 ± 9.4 23.2 ± 1.8 1.3 ± 3.2
Ethanol −0.24 102.0 ± 7.7 0.5 ± 2.4 4.9 ± 2.1
Acetone −0.23 53.1 ± 6.4 NDc 85.2 ± 1.3
Acetonitrile −0.15 96.2 ± 2.7 7.8 ± 1.4 89.0 ± 4.3
Isopropanol 0.1 81.3 ± 7.9 ND 97.0 ± 0.9
Benzene 2.0 37.9 ± 3.3 76.1 ± 4.7 92.8 ± 4.3
Toluene 2.5 63.5 ± 1.6 88.1 ± 4.0 90.1 ± 0.5
Cyclohexane 3.2 80.1 ± 2.7 92.7 ± 5.9 99.7 ± 1.8
n-hexane 3.5 53.1 ± 4.6 95.3 ± 10.6 98.6 ± 0.5
n-heptane 4.0 66.1 ± 2.8 96.9 ± 5.6 97.6 ± 1.3
Isooctane 4.5 85.5 ± 5.4 90.0 ± 10.9 98.4 ± 1.0

alog P value is the partition coefficient of an organic solvent between water and n-octanol phases

bAfter incubating EST4 for 12 h in different organic solvents, the residual enzymatic activity was measured in 100 mM Tris–HCl buffer (pH 8.0) at 30 °C using p-NP butyrate as the test substrate. An enzyme sample incubated in buffer only was used as the measure of 100 % activity

c ND not detectable