Enzymes employed for producing pulps

A purified lignin degrading enzyme F-1, F-2 or F-3, having the following characteristics:

• a) a substrate specificity such that each of F-1, F-2 and F-3 reacts upon syringylglycerol-.beta.-syringylether to produce .alpha.-syringyloxy-.beta.-hydroxypropiosyringon, 2-(2,6-dimethoxyphenoxy)-3-hydropropanol and 2,6-dimethoxyphenol;
• b) a substrate specificity such that each of F-1, F-2 and F-3 does not react on 4-O-ethyl-syringylglycerol-.beta.-syringylether;
• c) each of F-1, F-2 and F-3 exhibits a molecular weight change upon reaction with white birch dioxane lignin;
• d) each of F-1, F-2 and F-3 has an optimum pH level for enzyme activity of 4-5;
• e) each of F-1, F-2 and F-3 is stable at a pH of from 7 to 8;
• f) each of F-1, F-2 and F-3 exhibits an optimum temperature of activity ranging from 30.degree.-40.degree. C.;
• g) each of F-1, F-2 and F-3 exhibits a thermal stability up to 50.degree. C. in a 10 mM phosphate buffer solution (pH 7.0);
• h) each of F-1, F-2 and F-3 exhibits a relative activity in the presence of the substances shown in the following table:
• ______________________________________ Concen- Relative Activity Substance Added tration F-1 F-2 F-3 ______________________________________ No addition 0 mM 100% 100% 100% AlCl.sub.3 1 mM 61 65 65 BaCl.sub.2 1 mM 93 95 95 CaCl.sub.2 1 mM 94 95 95 MgCl.sub.2 1 mM 94 94 95 FeCl.sub.3 0.5 mM 15 31 25 MnCl.sub.2 1 mM 95 95 95 ZnCl.sub.3 1 mM 94 93 94 CoCl.sub.2 1 mM 97 94 96 CuCl.sub.2 1 mM 102 92 100 HgCl.sub.2 1 mM 11 21 18 SDS (sodium 1 mM 106 101 103 dodecyl sulfate) Briji-35 (commercial 1 PPM 105 100 101 name, surfactant) 2-Mercapto-ethanol 1 mM 10 19 15 EDTA 1 mM 98 102 101 Cysteine 1 mM 11 21 13 NaN.sub.3 1 mM 14 23 20 KCN 1 mM 10 17 16 ______________________________________
• i) each of F-1, F-2 and F-3 exhibits a molecular weight of about 88,000.+-.5,000 (SDS polyacrylamide electrophoresis);
• j) each of F-1, F-2 and F-3 exhibits an isoelectric point of about 2.5, 2.2 and 2.0, respectively;
• and
• k) each of F-1, F-2 and F-3 exhibits a measured increase of absorbance at 300 nm when 20 .mu.l of enzyme reacts with 10 .mu.l of 10 mM syringylglycerol-.beta.-syringylether solution which contains a small amount of dioxane and 720 .mu.l of a 50 mM acetate buffer solution (pH 5.0).