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β-1,4-葡聚糖内切酶egl3基因在乳酸乳球菌(Lactococcus lactis subsp. lactis MG1363)中分泌表达的研究

发表时间:2017-08-15  浏览量:38  下载量:4
全部作者: 刘秦华,邵涛,董志浩,李湘玉
作者单位: 南京农业大学饲草调制加工与贮藏研究所
摘 要: 采用重叠延伸PCR合成技术将乳酸乳球菌(Lactococcus lactis)分泌蛋白基因序列usp45(81 bp)和瑞氏木霉(Trichoderma reesei)β-1,4-葡聚糖内切酶成熟蛋白基因序列egl3(657 bp)连接成融合基因usp45-egl3,构建分泌型重组质粒pMG36e-usp45-egl3及重组乳酸乳球菌L. lactis subsp. lactis MG1363/pMG36e-usp45-egl3,分析重组乳酸乳球菌表达β-1,4-葡聚糖内切酶的效果及其降解滤纸和小麦秸秆的能力。结果表明,重组乳酸乳球菌L. lactis subsp. lactis MG1363/pMG36e-usp45-egl3经28 h培养能胞外分泌酶活为1 016 U•L-1的β-1,4-葡聚糖内切酶,可有效地降解羧甲基纤维素钠。在30℃恒温培养10 d时,重组乳酸乳球菌L. lactis subsp. lactis MG1363/pMG36e-usp45-egl3降解滤纸和小麦秸秆为其提供发酵底物,分别产生乳酸2.55 g•L-1和6.95 g•L-1,pH值分别降至5.10和4.84,干物质降解率分别为4.22%和29.36%.
关 键 词: 草原学;β-1,4-葡聚糖内切酶;egl3基因;乳酸乳球菌;分泌表达
Title: Research of secreting expression of β-1,4-endoglucanase egl3 gene in Lactococcus lactis subsp. lactis MG1363
Author: LIU Qinhua, SHAO Tao, DONG Zhihao, LI Xiangyu
Organization: Institute of Ensiling and Processing of Grass, Nanjing Agricultural University
Abstract: This study constructed a secretive recombinant plasmid pMG36e-usp45-egl3 and Lactococcus lactis subsp. lactis MG1363/pMG36e-usp45-egl3 with a fusion gene usp45-egl3 connected by the secreted protein gene sequence of usp45 (81 bp) from L. lactis and the coded mature-protein gene sequence of egl3 (657 bp) from Trichoderma reesei by the method of overlapping extension PCR. The expressive effect of recombinant L. lactis subsp. lactis MG1363 was analyzed, and the degradation capabilities of secreted β-1,4-endoglucanase on fiber and wheat straw were evaluated. The results show that the recombinant L. lactis subsp. lactis MG1363/pMG36e-usp45-egl3 can secrete β-1,4-endoglucanase with activity of 1 016 g•L-1 after culturing 28 h and degrading sodium carboxy methylcellulose effectively. After culturing at 30℃ for 10 days, recombinant L. lactis subsp. lactis MG1363/pMG36e-usp45-egl3 degrades paper and wheat straw to provide fermentation matrix, which produce 2.55 g•L-1 and 6.95 g•L-1 lactic acid and decrease pH values to 5.10 and 4.84, respectively. Dry matter degradation of paper and wheat straw are 4.22% and 29.36%, respectively.
Key words: range science; β-1,4-endoglucanase; egl3 gene; Lactococcus lactis; secreting expression
发表期数: 2017年8月第15期
引用格式: 刘秦华,邵涛,董志浩,等. β-1,4-葡聚糖内切酶egl3基因在乳酸乳球菌(Lactococcus lactis subsp. lactis MG1363)中分泌表达的研究[J]. 中国科技论文在线精品论文,2017,10(15):1729-1737.
 
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