The DL-lysine crystals from the racemization of L-lysine was treated as substrate with Hafnia alvei AS1.1009 intact cells as biocatalysts to produce crystal-line D-lysine with a yield of 56.6%from the reaction mixture...The DL-lysine crystals from the racemization of L-lysine was treated as substrate with Hafnia alvei AS1.1009 intact cells as biocatalysts to produce crystal-line D-lysine with a yield of 56.6%from the reaction mixture after simple purification.In the presence of 0.10 molar equivalent of salicylaldehyde,L-lysine race-mization can be completed within 4 h in 1.0 mol/L of NaOH at 100℃.The activation energy of the processes was 62187.86 J/mol.The characteristics of Hafnia alvei AS1.1009 decarboxylase were studied.Under the condi-tions of pH 8.0,temperature 37uC,cell concentration 10 g/L,tween-800.5 g/L,substrate concentration 30 g/L,and the specific activity of up to 3840 U,L-lysine can be completely degraded by the decarboxylase for 12 h under the optimal conditions.展开更多
基金This work was supported by the Innovation Foundation of China(No.02CJ-13-01-16)the Dean Foundation of Xuzhou Medical College(No.07KJZ07).
文摘The DL-lysine crystals from the racemization of L-lysine was treated as substrate with Hafnia alvei AS1.1009 intact cells as biocatalysts to produce crystal-line D-lysine with a yield of 56.6%from the reaction mixture after simple purification.In the presence of 0.10 molar equivalent of salicylaldehyde,L-lysine race-mization can be completed within 4 h in 1.0 mol/L of NaOH at 100℃.The activation energy of the processes was 62187.86 J/mol.The characteristics of Hafnia alvei AS1.1009 decarboxylase were studied.Under the condi-tions of pH 8.0,temperature 37uC,cell concentration 10 g/L,tween-800.5 g/L,substrate concentration 30 g/L,and the specific activity of up to 3840 U,L-lysine can be completely degraded by the decarboxylase for 12 h under the optimal conditions.
