Development of a Recombinant Ureolytic Lactococcus Lactis for Urea Removal
Development of a Recombinant Ureolytic Lactococcus Lactis for Urea Removal
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DOI：
10.3109/10731190903356420
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发表时间：
2009-01
期刊：
影响因子：
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通讯作者：
Suai Zhang;Dongxia Li;K. Tian;YueXia Bai;Hongkai Zhang;Cunjiang Song;M. Qiao;D. Kong;Yao-ting Yu
中科院分区：
文献类型：
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作者：
Suai Zhang;Dongxia Li;K. Tian;YueXia Bai;Hongkai Zhang;Cunjiang Song;M. Qiao;D. Kong;Yao-ting Yu
肾功能衰竭是一种常见病、多发病。能有效清除尿素的食品级重组菌在治疗肾功能衰竭方面具有巨大的潜力。非致病性菌株L.乳酸菌MG 1363转化了带有尿素酶基因的质粒pMG 36 α。转基因尿素酶在转基因L.乳酸菌MG 1363的产酶活性和尿素去除率。结果表明，重组L.乳酸菌MG 1363对pH和镍的依赖性。在pH 6.5和250 μM硫酸镍存在下，24小时内可去除50 ~ 60%的尿素。在模拟胃肠道环境中对尿素去除活性进行了评价。在暴露于酸性溶液（pH2.5-4.0）2小时后，然后将细胞在含有0.1 cfu/ml胆汁酸盐、30 mg/dl尿素和250μM NiSO 4的pH 6.8的培养基中生长。尿素的浓度随时间降低，并且在10小时和24小时分别去除约30%和65%。安全性试验通过给正常大鼠喂食L. lactis MG 1363或重组L.乳酸菌MG 1363。两种材料均未引起血细胞和血液生化指标的任何变化。两种材料之间的体重和饮水/摄食量无差异。这些结果表明，尿素酶基因修饰的乳酸乳球菌在胃肠道环境中去除尿素的安全性，可行性和能力。进一步的研究可能产生用于治疗慢性肾衰竭的食品级菌株。
Abstract Kidney failure is a common disease with high frequency. Food-grade recombinant bacteria that can effectively remove urea has great potential for treatment of renal failure. A nonpathogenic strain, L. lactis MG1363, was transformed with plasmid pMG36eure, which carries urease gene. The expression of transgene urease in genetically modified L. lactis MG1363 and the urease activity in removal of urea were investigated. It was found that the removal of urea by recombinant L. lactis MG1363 was pH- and nickel-dependent. At pH 6.5 and in the presence of 250 μM of NiSO4, 50∼60% of urea could be removed in 24 hours. The urea removal activity was also evaluated in imitative gastroenteric environment. After being exposed to acidic solution (pH2.5-4.0) for 2 hours, the cells were then grown in a medium containing 0.1 cfu/ml bile acid salt, 30mg/dl urea, and 250μM NiSO4 at pH 6.8. The concentration of urea decreased over time, and the removal was about 30% at 10 hours and 65% at 24 hours, respectively. The safety tests were performed by feeding normal rats with either L. lactis MG1363 or recombinant L. lactis MG1363. The two materials did not cause any changes in blood cells and blood biochemical indexes. There were no differences in terms of body weight and water/food consumption between the two materials. These results indicate the safety, feasibility, and capacity of urease gene modified Lactococcus Lactis in removal of urea under the gastroenteric circumstances. Further investigation may generate a food-grade strain for treatment of chronic renal failure.