Optimization of fed-batch fermentation and direct spray drying in the preparation of microbial inoculant of acetochlor-degrading strain Sphingomonas sp DC-6
Optimization of fed-batch fermentation and direct spray drying in the preparation of microbial inoculant of acetochlor-degrading strain Sphingomonas sp DC-6
复制标题
补料发酵和直接喷雾干燥制备乙草胺降解菌株鞘氨醇单胞菌DC-6菌剂的优化
DOI：
10.1007/s13205-018-1324-x
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发表时间：
2018
期刊：
影响因子：
2.8
通讯作者：
Hong Qing
中科院分区：
文献类型：
--
作者：
Wang Hui;Jiang Kun;Zhu Ziwei;Jiang Wankui;Yang Zhangong;Zhu Shijun;Qiu Jiguo;Yan Xin;He Jian;He Qin;Hong Qing
微生物接种剂的制备是其大规模生物修复应用的前提。本研究中，鞘氨醇单胞菌Sphingomonassp.采用高效乙草胺降解菌DC-6对接种剂的制备工艺进行了研究。采用响应面方法(RSM)对液体发酵(SMF)进行优化，可使液体接种物的生物量提高22%。在优化的发酵条件下，利用7.5-L生物反应器，菌体生物量提高了2.18倍，培养周期缩短了14.58%。然而，液体接种剂中只有不到0.4%的活细胞在储存180天后存活。因此，采用优化的喷雾干燥条件生产高活性粉末(2.11 × 1012cfu g− 1粉末)，在不添加添加剂的情况下，其180天的存活率仍保持在90.5%。储存180d的菌粉与原粉具有相同的降解性能，能在48h内完全降解200mgL− -1乙草胺，证明菌株DC-6适合工业化生产菌粉，为制备农药降解微生物接种剂提供了一条潜在的途径。
Microbial inoculant preparation is a prerequisite for its application in large-scale bioremediation. In the present study,Sphingomonassp. DC-6, an efficient acetochlor-degrading strain, was used to investigate the process of preparing the inoculant. Optimization of submerged fermentation (SmF) by response surface methodology (RSM) resulted in a first 22% increase in biomass of liquid inoculant. Then, a biomass increase of 2.18 times with 14.58% shortened incubation period was further obtained in optimized medium using a 7.5-l bioreactor. However, less than 0.4% viable cells in liquid inoculant survived after 180-days storage. Thus, optimized spray drying conditions were subsequently employed for the production of high viability powder (2.11 × 1012cfu g− 1powder) without additive and its survival ratio (SR) after 180-days storage was still maintained at 90.5%. Both the 180-days stored powder and the original powder showed the same degradation performance, being able to completely degrade 200 mg l− 1acetochlor within 48 h. This study demonstrated that strain DC-6 was suitable for industrial production of bacteria powder and provided a potential approach for the preparation of pesticide-degrading microbial inoculant.