a reaction bomb preheated to 45 u00b0 c and incubated under an increased oxygen pressure of 1 10 bar for 1 4 hours thereafter the pulp is washed over a nylon screen 30 am and extracted for 1 hour at 60 u00b0 c at a pulp consistency of 2 with 8 of naoh per g of pulp after renewed washing of the pulp the kappa number is determined see table 1 for the result 5 g of bone dry pulp softwood o 2 delignified pulp consistency 30 about 17 g moist are added to the following solutions a 83 7 mg of ethyl 4 n acetyl hydroxylamino benzoate are added to 20 ml of tap water while stirring and the ph is adjusted with 0 5 mol l of h 2 so 4 solution such that ph 4 5 results after addition of the pulp and the enzyme b an amount of laccase from trametes versicolor is added to 5 ml of tap water such that an activity of 15 u 1 u conversion of 1 u03bcmol of abts minute ml of enzyme per g of pulp results solutions a and b are brought together and topped up to 33 ml after addition of the pulp the mixture is mixed with a dough kneader for 2 minutes the pulp is then introduced into a reaction bomb preheated to 45 u00b0 c and incubated under an increased oxygen pressure of 1 10 bar for 1 4 hours thereafter the pulp is washed over a nylon.