Cloning Of β-1,3-1,4 Glucanase Gene From Bacillus Licheniformis And Its Expression In Lactococcus Lactis

β-glucanase can help degradeβ-glucan and effectively improve digestibility of animal diets. The research and application ofβ-glucanase as a silage additive are developing quickly, and the scope of utilization is on the rise. Through extensive practical application, it has been generally accepted by the animal feed additive industry. However, the production process of enzyme is quite complicated and the cost of it is high. Ifβ-glucanase could be expressed in GRAS host bacteria such as Lactis acid bacteria, it can be added directly to silage without any process such as production, fermentation and purification of the enzyme.In the research,β-1,3-1,4- glucanase from Bacillus licheniformis is cloned and sequenced, then Homology between the gene sequence and otherβ-1,3-1,4- glucanase from Bacillus licheniformis was analyzed. The gene ofβ-1,3-1,4- glucanase was ligated into pET32a and transformed in Escherichia coli BL21, eventually the effective expression was accomplished. After determined its effectiveness, the gene was used to construct a Lactococcus lactis expression vector pMG-glu, and transformed in Lactococcus lactis MG1363 by Electroporation, finally an effective transformant was obtained. This work has laid the foundation for preparing an excellent lactic acid bacteria addictive for silage.