基因重组木聚糖酶PTX2高密度发酵制备及其功效研究

High-density Fermentation and Functional Characterization of Recombinant Xylanase PTX2

利用15L液体发酵系统对基因重组木聚糖酶PTX2进行高密度发酵制备,结果显示,在搅拌速度450r/min,甲醇流速6mL/(L·h)条件下,连续诱导96h后,其最大菌体质量浓度为78g/L,最高酶活力达560U/mL;在断奶仔猪饲粮中添加500U/kg未经任何处理的液体基因重组木聚糖酶PTX2,仔猪平均日增体质量(ADG)提高16.9%,料与体质量比显著降低,饲粮粗蛋白、灰分、钙及粗纤维表观消化率也有增加的趋势。该研究结果初步证实了重组木聚糖酶PTX2在饲料及食品工业中具有较大的应用价值和开发前景。

Recombinant xylanase PTX2 was prepared in a 15 L fermentor through high-density fermentation. After methanol induction at 28 ℃ for 96 h, the highest cell density and the maximal xylanase activity were achieved to 78 g/L and 560 U/mL, respectively. Diet supplemented with 500 U/kg of unprocessed PTX2 could result in an increase of average body weight gain of weaned piglets by 16.9%, an obvious decrease in intake/body weight gain ratio, and an increasing trend of apparent digestibility of crude protein （CP）, ash, calcium and crude fiber （CF）. Therefore, the potential benefit of PTX2 in feeding weaned piglets demonstrates an attractive application value and industrial development of this enzyme.