【摘要】：This paper was studied the influences of the different concertration of rare earth ions (lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium) on cellulase degradation cellulose three substrates (filter paper, carboxymethylcellulose sodium, cellobiose) systemically, as well as the effection of rare earth ion which was the effect remarkable rare earth on the cellulose complexes with citric acid on the cellulase enzyme activity, obtained the best activation rare earth ion and the best activation density. The results showed: The effection of the rare earth on enzyme activity decided to the rare earth density. the cellulase activity was activated by the low concentration rare earth. Contrarily, the high concentration had the inhibition action to the enzyme activity.The Nd3+, Eu3+ had the most remarkable activition among the extent of experiment concentration for 1.0×10-9-1.0×10-7 g·L-1. the free rare earth ion on the cellulase enzyme activity was better than the rare earth complexes of citrate.
The effect mechanism of rare earth on the cellulase activity and its structure had primarily discussed by atom force microscope, polyacrylamide gel electrophoresis(PAGE), SDS-polyacryla- mide gel electrophoresis(SDS-PAGE). By atom force microscope showed: the high concentrated rare earth ion made cellulase outside rough and uneven in surface, the edge irregular, it was obvious accumulated, conglomerated. But the low concentration have no effect on cellulase surface topography; By PAGE and SDS-PAGE showed: the cellulase electrophoresis band of some component had shifted up, conglomerated when it edded the high concentrated rare earth ion; And the low concentration have no effect on cellulase electrophoresis band. So the high concentrated rare earth ion made the cellulase accumulated, affected its structure, inhibited cellulase activity so made the efficiency of the cellulase degeneration cellulose was reduced. Contrarily, the low concentratio- n rare earth ion does not have the influence on the cellulase structure nearly. Maybe it adsorbe in the cellulase CBD or CD linke among them, improve the cellulase and cellulose combining better each other for increasing the catalyze efficiency.
Using the remarkable activition rare earth ion and the best density on cellulase activity to search after the influence of rare earth ion and the cellulase to degrades the native cellulose wild bamboo. It showed that Nd3+ was the most remarkable activation function. Through the orthogonal experiment, the best technological conditions of the rare earth ion and the cellulase to degrade the wild bamboo was: pH 4.5, temperature for 52°C, reaction time 75 min.
This research results had revealed the influence of rare earth ion on cellulose enzyme activity, and had discussed the rare earth ion and the cellulase effect mechanism, for increasing the cellulose enzyme degradation cellulose hydrolyzation efficiency, resolving the energy crisis have important practical or immediate significance and theory value.