Efficient Expression of Xylanase by Codon Optimization and Its Effects on the Growth Performance and Carcass Characteristics of Broiler
Efficient Expression of Xylanase by Codon Optimization and Its Effects on the Growth Performance and Carcass Characteristics of Broiler
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DOI：
10.3390/ani9020065
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发表时间：
2019-02-01
期刊：
影响因子：
3
通讯作者：
Bai, Xi
中科院分区：
文献类型：
--
作者：
Hu, Hong;Dai, Sifa;Bai, Xi
本研究的目的是通过密码子优化策略提高里氏木霉木聚糖酶（XynB）在毕赤酵母中的表达水平，并评估其对肉鸡生长性能和胴体特性的影响。根据毕赤酵母基因组密码子偏倚，通过全基因组装优化合成里氏木霉XynB基因，以提高其在毕赤酵母中的表达水平。大约 180 个目标突变已成功引入天然 XynB。诱导96小时后，毕赤酵母pPICZaA-optiXynB分泌的木聚糖酶(optiXynB)的最大活性为1299 U/mL。纯化的重组 optiXynB 的分子量为 24 kDa。 optiXynB 在 pH 5.0 和 50 摄氏度下表现出最高活性。重组酶对桦木木聚糖、山毛榉木木聚糖和燕麦木聚糖具有高度特异性。在肉鸡实验中，总共 200 只 Arbor Acre 肉鸡（一天龄）被随机分为四组，饲喂含有 0（对照组）、500、1000 和 1500 IU/kg optiXynB 的基础日粮。膳食中 1000 和 1500 IU/kg optiXynB 显着增加 (p < 0.05) 最终体重和体重增加；与对照组相比，日粮中 500、1000 和 1500 IU/kg optiXynB 显着增加 (p < 0.05) 预掏膛重量、屠宰百分比和掏膛重量。在肉鸡日粮中添加 optiXynB 会线性增加最终体重、增重、胸肌重量和腿部肌肉重量，但饲料转化率会线性降低 (p < 0.05)。此外，在肉鸡日粮中添加 optiXynB 会线性和二次增加预内脏重量、屠宰百分比和内脏重量 (p < 0.05)。巴斯德毕赤酵母 pPICZaA-optiXynB 重组 optiXynB 有利于改善肉鸡的生长性能和胴体特性。
The aim of the present study was to improve the expression level of Trichoderma reesei xylanase (XynB) in Pichia pastoris through a codon optimization strategy and evaluate its effects on the growth performance and carcass characteristics of broiler. According to the codon bias of Pichia genome, the XynB gene from T. reesei was optimized and synthesized by whole gene assembly to improve its expression level in P. pastoris. Approximately 180 target mutations were successfully introduced into natural XynB. The maximum activity of xylanase (optiXynB) secreted by P. pastoris pPICZaA-optiXynB was 1299 U/mL after 96 h induction. Purified recombinant optiXynB had the molecular weight of 24 kDa. The optiXynB presented highest activity in pH 5.0 and 50 degrees C. The recombinase was highly specific towards birchwood xylan, beechwood xylan, and oat-spelt xylan. In the broiler experiment, a total of 200 Arbor Acre broilers (one day old) were randomly allocated into four groups fed with basal diets containing 0 (control group), 500, 1000, and 1500 IU/kg optiXynB. Dietary 1000 and 1500 IU/kg optiXynB significantly increased (p < 0.05) final weight and body weight gain; dietary 500, 1000, and 1500 IU/kg optiXynB significantly increased (p < 0.05) pre-evisceration weight, dressed percentage, and eviscerated weight compared with the control group. Inclusion of optiXynB in broiler diets linearly increased final weight, body weight gain, breast muscle weight and leg muscle weight, but linearly decreased feed conversion rate (p < 0.05). Furthermore, inclusion of optiXynB in broiler diets linearly and quadratically increased pre-evisceration weight, dressed percentage, and eviscerated weight (p < 0.05). The recombinant optiXynB from P. pastoris pPICZaA-optiXynB was beneficial in improving growth performance and carcass characteristics of broilers.