The resultant crude enzyme extraction was submitted to puri-
fication of tannase by the method of Mata-Gomez ( Marco et al.,
2009). The crude enzyme solution was precipitated by ammonium
sulfate in a saturation range of 60e90% at 4 C for 3 h followed
by centrifugation in an Avanti J-25 centrifuge using a JA10 rotor
(Beckman Coulter, USA) at 17,700 g (10,000 r/min) and 4 C for
20 min. The resultant pellet was extensively dialyzed in a 30 kDa
cut-off dialysis tube against 10 mmol/L sodium citrate buffer (pH
5.0) at 4 C for 24 h, and subsequently separated on a DEAESepharose
column (2 20 cm) previously equilibrated with
10 mmol/L sodium citrate buffer (pH 5.0). After gradient elution
with 0e1 mol/L NaCl in 10 mmol/L sodium citrate buffer (pH 5.0),
tannase fractions which were pooled within 0.3e0.5 mol/L NaCl
was concentrated by ultrafiltration through an Amicon Ultra-4
Centrifugal Filter Unit (cut-off at 30 KDa), and further applied to a
Sephacyl S-200 HR column (1.6 100 cm) followed by elution with
50 mmol/L sodium citrate buffer at 0.5 mL/min. The purification
steps yielded a tannase solution with an enzymatic activity of
89.33 U/mL, protein concentration of 0.91 mg/mL, specific activity
of 97.84 U/mg. The enzyme was kept at 4 C and diluted to a
desirable concentration before use.
2
The resultant crude enzyme extraction was submitted to puri-fication of tannase by the method of Mata-Gomez ( Marco et al.,2009). The crude enzyme solution was precipitated by ammoniumsulfate in a saturation range of 60e90% at 4 C for 3 h followedby centrifugation in an Avanti J-25 centrifuge using a JA10 rotor(Beckman Coulter, USA) at 17,700 g (10,000 r/min) and 4 C for20 min. The resultant pellet was extensively dialyzed in a 30 kDacut-off dialysis tube against 10 mmol/L sodium citrate buffer (pH5.0) at 4 C for 24 h, and subsequently separated on a DEAESepharosecolumn (2 20 cm) previously equilibrated with10 mmol/L sodium citrate buffer (pH 5.0). After gradient elutionwith 0e1 mol/L NaCl in 10 mmol/L sodium citrate buffer (pH 5.0),tannase fractions which were pooled within 0.3e0.5 mol/L NaClwas concentrated by ultrafiltration through an Amicon Ultra-4Centrifugal Filter Unit (cut-off at 30 KDa), and further applied to aSephacyl S-200 HR column (1.6 100 cm) followed by elution with50 mmol/L sodium citrate buffer at 0.5 mL/min. The purificationsteps yielded a tannase solution with an enzymatic activity of89.33 U/mL, protein concentration of 0.91 mg/mL, specific activityof 97.84 U/mg. The enzyme was kept at 4 C and diluted to adesirable concentration before use.2
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