医用脲酶菌的固定化比较研究

Comparative study on immobilizition of urease-producing bacteria used in therapy

以聚乙烯醇为载体,分别通过化学法与物理法对医用脲酶菌进行包埋,并比较了2种方法所制备微球的性能及血清尿素清除活性.化学法采用硼酸交联,当调节硼酸pH至6.5时所得固定化微球比未调硼酸pH(4.0)的微球有较高的机械强度及尿素吸收活性;物理法采用冷冻交联,所得微球粒径均一,机械强度较好,冷冻交联微球吸收尿素的活性与未调pH(4.0)的硼酸交联微球接近,而略低于pH 6.5硼酸交联微球.体外尿毒症模拟血清尿素清除试验表明,化学法硼酸(pH 6.5)交联的固定化脲酶菌尿素吸收活性最高,8h尿素清除率达97%,若经培养液预培养24h,则尿素吸收活性明显增加,6h清除率为97.2%.

Urease-producing bacteria used in therapy were entrapped through chemical and physical methods by use of polyvinyl alcohol as the carrier.The properties and serum urea clearance activities of two sorts of microspheres were compared.Microsphere of chemical cross-linking with boric acid pH 6.5 had higher mechanical strength and urea clearance activity than that with boric acid pH 4.0.The freeze-thawing method was employed for physical cross-linking.Microsphere of physical cross-linking had a uniform diameter distribution and good mechanical strength.Its urea clearance activity was almost equal than microsphere with boric acid pH 4.0,and slightly lower than microsphere with boric acid pH 6.5.The experiment of serum urea clearance in vitro showed that microsphere of chemical cross-linking with boric acid pH 6.5 had the highest urea clearance rate of 97% in 8 h.Urea clearance rate was evidently increased to 97.2% in 6 h if pre-culture of the microsphere was carried out for 24 h.