TEHRAN (FNA)- Iranian researchers from Tehran University of Medical Sciences succeeded in the enzyme degradation of nitrophenol
pollutants by using porous silica beads.
By the electroreduction  of nitrophenol
isomer using stationary and rotating Cu electrodes and Ti(S04)2 as additional agent, aminophenols were obtained in good yield.
Degradation of nitrophenol
under sonication can lead to defacement of ester hydrolysis kinetics and this issue has been discussed in detail in our previous paper .
The retention of nitrophenol
isomers was even stronger and a mixture of methanol and water (80/20) was used to get the following capacity factors k' for both sorbents: o-nitrophenol
Nonspecific esterase activity was measured as the average change in optical density per minute at 400 nm and then converted to units (micromoles of 4-NPC hydrolyzed per minute) using the extinction coefficient for nitrophenol
of 19,800 [M.
The yield of nitrophenol
was calculated from [epsilon] = 4400 [M.
A solution of 4-nitrophenol
in buffer was used to determine the molar absorptivity of the nitrophenol
produced by the hydrolysis of paraoxon; the molar absorptivity at 405 nm (pH 8.
Activity of AKP was expressed as specific activity (U/g protein), where one unit (U) is equal to the amount of enzyme necessary to produce 1 [micro]mol of nitrophenol
(from [rho]-nitrophenyl-phosphate) per min at 37[degrees]C.
A mixture of ozone gas and air produced by a laboratory ozone generator was bubbled through the aqueous solution of nitrophenol
The amount of nitrophenol
released was determined by comparison with a standard nitrophenol
curve and expressed as [micro]mol/30 min/mg protein.