聚丙烯酰胺固定化细胞酶解尿素的研究  

A STUDY OF UREA HYDROLYSIS BY PROTEUS MORGANII CELLS ENTRAPPED IN POLYACRYLAMIDE GEL

作　　者：杨连栋[1] 陈毓琛[2] 

机构地区：[1]北京石油化工科学研究院 [2]大连理工大学化工学院环境工程教研室,116012

出　　处：《水处理技术》1990年第3期223-229,共7页Technology of Water Treatment

摘　　要：聚丙烯酰胺包埋摩尔根氏变形杆菌凝胶具有较高的酶解尿素活性,菌含量10%左右,酶活力收率在60%以上,菌体不易泄漏,机械强度较好。冰箱(4℃)内存放一个月活性无明显变化;室温下存放10个月后酶活力仍保持50%以上。影响酶活性的因素为湿菌与尿素比例,反应系统pH值及反应温度。65℃时酶活力最大;酸性环境利于水解反应的进行。该凝胶与尿素反应的表观活化能为42 977 J/mol;表观米氏常数为2.67×10^(-2)mol/L(37℃)。尿素在凝胶内的扩散是水解反应的控制步骤。由数模求得有效内扩散系数为D_(of/37℃)=1.75×10^(-10)m^2/S,D_(of/65℃)=6.67×10^(-10)m^2/s。Polyacrylamide gel entrapping Proteus Morganii cells possesses high urease activity. Optimum cell content ratio is about 10%. The cells will not leave the gel when they are used. The urease activity yield ratio after immobilization is more than 60%, the urease activity has a little change only when the gel is stored in refrigerator (4℃) for a month, and 50% of the urease remain active when it is kept at room temperature for 10 months.The main factors effecting urea hydrolysis by the gel are the weight ratio of cells to urea, reacting temperature and pH value in the reacting liquid phase.Optimum reaction temperature is 65℃, hydrolysis reaction is suitable in acidic medium. The apparent coefficient K_m in Michaelis-Menten equation can be calculated as 2.67×10^(-2) mol/L (37℃) for the gel, and the apparent energy of activation in the reaction is 42 977 J/mol. The effective coefficient of internal diffusion of urea in the gel is D_(ef,37℃)=1.75×10^(-10) m^2/s or D_(ef,65℃)=6.67×10^(-10) m^2/s. The diffusion resistance of urea in gel is the rate-controlling step in the reaction.

关 键 词：聚丙烯酰胺 尿素废水 固定化细胞 

分 类 号：X789.03[环境科学与工程—环境工程]