海洋弧菌NTi产琼胶酶的发酵条件优化

Process Optimization of Agarases Fermentation by Vibrio natriegens NTi

以琼胶酶活力为主要指标,采用单因素与响应面相结合的方法,对降解琼胶的海洋弧菌NTi(Vibrio natriegens NTi)发酵产琼胶酶的摇瓶发酵培养基和发酵条件进行优化。结果表明,α-乳糖对菌株产酶具有较强的抑制作用,NH+4不利于菌株生长和产酶。培养基分别以3. 3 g/L琼脂、6. 33 g/L酵母膏为唯一碳源及氮源,添加20 g/L的Na Cl,发酵海洋弧菌V. natriegens NTi产琼胶酶的效果最佳。发酵过程中的p H值、接种量、装液量、温度、发酵时间最优值分别为6. 5、2%、32 m L、27℃和24 h。优化后,该菌产琼胶酶活力达到2. 81 U/m L,比优化前增加了230%。

The single factor test and response surface methodology were used to optimize the fermentation medium and fermentation conditions of agarase produced by marine Vibrio natriegens NTi,and the agarase activity was taken as main indicator.The results showed thatα-lactose had a significant inhibitory effect on the agarase production,while ammonium ion was not conducive to cell growth and enzyme production.The optimal composition of culture medium for agarase-producing was:3.3 g/L agar as the sole carbon source,6.33 g/L yeast extract as the sole nitrogen source and 20 g/L NaCl.Meanwhile,the optimum conditions for agarase production were pH=6.5,inoculation amount 2%,liquid volume 32 mL,temperature 27℃ and fermentation time 24 h,respectively.Under the optimum conditions,agarase activity reached 2.81 U/mL after 24 h of fermentation and increased by 230% compared with the activity under the initial medium and conditions.