full issue - Association of Biotechnology and Pharmacy
full issue - Association of Biotechnology and Pharmacy
full issue - Association of Biotechnology and Pharmacy
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Current Trends in <strong>Biotechnology</strong> <strong>and</strong> <strong>Pharmacy</strong><br />
Vol. 5 (3) 1273 -1281 July 2011, ISSN 0973-8916 (Print), 2230-7303 (Online)<br />
1277<br />
the increasing concentration <strong>of</strong> H 2<br />
O 2<br />
<strong>and</strong><br />
maximum decolorization was observed at a<br />
concentration <strong>of</strong> 1.0 mM H 2<br />
O 2<br />
that remained<br />
substantially unaffected till 1.2 mM H 2<br />
O 2<br />
. At<br />
concentrations <strong>of</strong> hydrogen peroxide beyond 1.2<br />
mM there was decrease in decolorization <strong>of</strong> both<br />
RB15 <strong>and</strong> RR4, although on comparison RR4<br />
showed more reduction in decolorization than<br />
RB15.<br />
Effect <strong>of</strong> temperature <strong>and</strong> pH on the extent <strong>of</strong><br />
reactive dye decolorization : The results <strong>of</strong><br />
temperature activity plot are shown in Fig.4. Both<br />
dyes (RB15 <strong>and</strong> RR4) showed sufficient<br />
decolorization in temperature range <strong>of</strong> 40°C to<br />
50°C. Buffers (pH 2.0 to pH 10.0) were used to<br />
find out the range <strong>of</strong> pH in which significant<br />
decolorization was observed. The results <strong>of</strong> pH<br />
activity plot are shown in Fig.5. An acidic range<br />
<strong>of</strong> pH (4.0 to 5.0) was better suited for dye<br />
decolorization. A pH optimum recorded for both<br />
the dyes was pH 5.0. The extent <strong>of</strong> decolorization<br />
significantly decreased in alkaline medium.<br />
Effect <strong>of</strong> time on the extent <strong>of</strong> reactive dye<br />
decolorization : The extent <strong>of</strong> decolorization <strong>of</strong><br />
both dyes RB15 <strong>and</strong> RR4 as a function <strong>of</strong> time<br />
is shown in Fig.6. RB15 showed maximum<br />
decolorization in 90min whereas RR4<br />
decolorized maximally after 3h <strong>of</strong> incubation at<br />
40°C. However, no effective increase was<br />
observed when the dyes were further incubated<br />
for longer durations. Sufficient amount <strong>of</strong> RB15<br />
was decolorized within 60 min while the<br />
Reactive Blue 15 Reactive Red 4<br />
Fig.4:Temperature activity plot. Reactive dye<br />
decolorization as a function <strong>of</strong> temperature (20°C to 90°C).<br />
Reactive Blue 15 Reactive Red 4<br />
Fig.6: Time activity plot. Reactive dye decolorization as<br />
a function <strong>of</strong> time (30 min to 300 min).<br />
decolorization <strong>of</strong> RR4 was slow in the same time<br />
interval.<br />
Reactive Blue 15 Reactive Red 4<br />
Fig.5: pH activity plot. Reactive dye decolorization as a<br />
function <strong>of</strong> pH (pH 2.0 to pH 10.0). The buffers were<br />
glycine-HCl (pH 2.0, 3.0 <strong>and</strong> 4.0), sodium acetate (pH 5.0),<br />
sodium phosphate (pH 6.0, 7.0 <strong>and</strong> 8.0), <strong>and</strong> Tris-HCl (pH<br />
9.0 <strong>and</strong> 10.0).<br />
Discussion<br />
The reactive dye decolorization ability <strong>of</strong><br />
peroxidase isolated from Trichosanthes dioica<br />
has been evaluated in the presence <strong>of</strong> redox<br />
mediators under different sets <strong>of</strong> conditions. The<br />
enzyme pointed gourd peroxidase (PGP) has<br />
been partially purified <strong>and</strong> used for studying<br />
decolorization <strong>of</strong> reactive dyes using simple<br />
techniques. The emphasis on enzyme purification<br />
Simple approach to reactive dye decolorization