产琼胶酶菌株海洋弧菌NTi罐上工艺优化及中试放大

Fermentation Optimization and Pilot Production of Agarase from Vibrio sp. NTi

对产琼胶酶菌株海洋弧菌NTi进行7 L罐发酵工艺优化以及20 L和200 L发酵的中试放大试验。通过测定发酵过程琼胶酶活力及生物量考察p H、转速、温度、额外添加碳源、不同补料方式对菌株海洋弧菌NTi产琼胶酶的影响,确定该菌株7 L罐发酵最佳工艺为p H 7.5或自然发酵,转速700 r/min,发酵温度27℃,以琼脂为唯一碳源,所产琼胶酶活力最高达3.37 U/m L。将小试发酵工艺放大至20 L和200 L发酵罐进行试验,结果表明,20 L和200 L罐上发酵产酶规律与7 L罐基本一致,且其琼胶酶产量进一步提高,其中20 L罐琼胶酶活力最高达3.66 U/m L,200 L罐琼胶酶活力最高达3.73 U/m L,分别比7 L罐提高了8.5%,10.5%,中试放大效果良好。

In this study, agarase-producing strain Vibrio. sp NTi was cultured in 7 L bioreactor and the effects of p H, stirring rate, temperature, carbon source and different fed-batch culture methods on agarase production were determined by measuring the changes of biomass and agarase activity during fermentation. The highest agarase activity reached3.37 U/m L at the conditions of p H 7.5 or natural fermentation, 700 r/min, 27 ℃, and agar as the sole carbon souce. The optimal fermention process obtained from 7 L bioreactor was carried out in 20 L and 200 L bioreactors. It was shown that the maximum agarase activitives in 20 L and 200 L bioreactors were 3.61 U/m L and 3.73 U/m L respectively, which were 8.5% and 10.5% over the activity in 7 L bioreactor. This result indicated that the fermentation process for agarase production in laboratory scale was easy to scale up.