d(GC) - Association of Biotechnology and Pharmacy
d(GC) - Association of Biotechnology and Pharmacy
d(GC) - Association of Biotechnology and Pharmacy
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Current Trends in <strong>Biotechnology</strong> <strong>and</strong> <strong>Pharmacy</strong><br />
Vol. 6 (2) 145-165 April 2012, ISSN 0973-8916 (Print), 2230-7303 (Online)<br />
tannase from P. charlesii <strong>and</strong> P. crustosum<br />
retained 100% activity at 40 <strong>and</strong> 50 ºC,<br />
respectively (52).<br />
Mondal et al. (66) observed that the<br />
partially purified tannase was active over a pH<br />
range 3.5 to 6.0 <strong>and</strong> showed an optimum activity<br />
at pH 5.7 <strong>and</strong> found active over a temperature<br />
range <strong>of</strong> 20 to 70 ºC with optimum activity at 60<br />
ºC. Mahapatra et al. (96) discussed the effect <strong>of</strong><br />
pH on purified tannase in the range <strong>of</strong> 3.5 to 6.0,<br />
<strong>and</strong> the enzyme was active at acidic pH while<br />
activity decreased as the pH approached the<br />
alkaline range <strong>and</strong> optimum activity was recorded<br />
at pH 5.0. There are several reports mentioning<br />
the optimum pH to be 5.5 as in the case <strong>of</strong><br />
tannase obtained from A. flavus, A. oryzae, <strong>and</strong><br />
pH 6.0 in the case <strong>of</strong> tannase obtained from P.<br />
chrysogenum (106) <strong>and</strong> A. niger (85).<br />
The optimum pH for the tannase activity<br />
from P. variotii ranged from 5.0 to 7.0 (23). Also<br />
optimum temperature <strong>of</strong> 40 °C for tannase activity<br />
<strong>and</strong> stability was similar to those reported from<br />
A. niger (85). According to Sharma et al. (99),<br />
tannase from P. variable was found to be active<br />
in the temperature range <strong>of</strong> 25-80 ºC in three<br />
enzyme formulations (crude, purified <strong>and</strong><br />
immobilized) with temperature optima at 50 ºC.<br />
In many fungi, temperature optima for tannase<br />
activity have been reported to be in the range <strong>of</strong><br />
30-40 ºC (104). However, tannases from A. niger<br />
van Tieghem (83) <strong>and</strong> Bacillus cereus KBR 9 (66)<br />
have been reported to have a temperature optima<br />
between 45 <strong>and</strong> 60 ºC <strong>and</strong> also temperature<br />
optimum <strong>of</strong> 60-70 ºC has been reported for A.<br />
niger tannase (88). There was no change in the<br />
temperature optima when tannase <strong>of</strong> P. variable<br />
was immobilized (99) as against the findings<br />
where the temperature optima <strong>of</strong> immobilized <strong>and</strong><br />
free A. niger tannase has been reported at 40 ºC<br />
<strong>and</strong> 30 ºC, respectively (102). This result is<br />
supported by the findings where thermal stability<br />
<strong>of</strong> A. niger tannase is significantly improved by<br />
the immobilization process (101). Also functional<br />
pH range (3.0-10.0) was found broader in all the<br />
155<br />
three forms <strong>and</strong> more than 80% relative activity<br />
at pH 3.0 was observed. In many reports, the pH<br />
optimum has been reported in the range <strong>of</strong> pH<br />
3.0 - 6.0 (106, 107). Two pH optima peaks at 4.0<br />
<strong>and</strong> 6.0 have been reported for A. niger van<br />
Tieghem tannase (88). Also, stability <strong>of</strong> C.<br />
parasitica tannase was reported over a pH range<br />
<strong>of</strong> 4.0 - 7.5 for 12 h (55) <strong>and</strong> A. niger PKL tannase<br />
in a narrow pH range <strong>of</strong> 4.5 to 5.5 (1).<br />
The crude tannase produced by<br />
Paecilomyces variotii showed optimum activity<br />
at pH 6.5, whereas purified tannase showed pH<br />
optima at 5.5 (108). The crude tannase from<br />
Paecilomyces variotii was stable in a temperature<br />
range from 20-70 ºC, where it retained 96%<br />
activity at 20 ºC (108). A comparable summary<br />
<strong>of</strong> pH optima <strong>and</strong> stability is given in table 3.<br />
Substrate Specificity: There is no consistency<br />
reported on substrate specificity for tannase<br />
activity. P. variable tannase showed broad<br />
substrate specificity with more affinity for tannic<br />
acid having a K m <strong>of</strong> 32 milliMolar (mM) followed<br />
by methyl gallate (14 mM) <strong>and</strong> propyl gallate (12<br />
mM). The V max /K m ratio for tannic acid is almost<br />
four times higher than that for methyl gallate <strong>and</strong><br />
1.2 times for propyl gallate (65). Other report on<br />
K m for tannic acid was <strong>of</strong> 0.28 mM for A. niger<br />
MTCC 2425 tannase (95). A commercial grade<br />
(Sigma, USA) tannase from A. oryzae was found<br />
to have a K m <strong>of</strong> 0.42 M with tannic acid (99).<br />
Battestin <strong>and</strong> Macedo, (60), studied the effect <strong>of</strong><br />
substrate concentration on tannase activity <strong>and</strong><br />
the graphical analysis <strong>of</strong> the effect <strong>of</strong> substrate<br />
concentration on tannase activity yielded K m <strong>of</strong><br />
0.61 ìM <strong>and</strong> V max <strong>of</strong> 0.55 U/mL proteins. The K m<br />
values for tannase from C. parasitica using tannic<br />
acid <strong>and</strong> methyl gallate as substrate were<br />
reported as 0.94 mM <strong>and</strong> 7.49 mM respectively<br />
(55).<br />
Effect <strong>of</strong> Metal Ions: More than 75% <strong>of</strong> enzymes<br />
require metallic ions as c<strong>of</strong>actors to demonstrate<br />
their maximal catalytic capacities. At low<br />
Overview on production <strong>and</strong> characterization <strong>of</strong> tannases
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