冷风干燥制备高活菌的恶臭假单胞菌菌粉

Preparation of high viable count Pseudomonas putida bacteria powder by cold blast drying

【目的】获得高活菌恶臭假单胞菌菌粉,提高菌体干燥及保藏存活率。【方法】选用冷风干燥法制备活菌粉,并优化吸附载体与保护剂。【结果】冷风干燥制备恶臭假单胞菌菌粉干燥存活率普遍达到65%以上,显著优于喷雾干燥(24%);对载体与保护剂进行正交试验优化,确定了载体为混合的硅藻土和碱处理玉米芯粉,混合比为1:2,保护剂(质量比)为甘露醇7%、谷氨酸钠5%、甘油1%,制得菌粉活菌数为1.03×1011 CFU/g,室温保藏30 d和4°C保藏60 d存活率分别达到40.54%和71.67%。【结论】冷风干燥温度相对较低(10-40°C),对菌体损伤小,碱处理玉米芯粉、甘露醇和谷氨酸钠是提高菌粉保藏存活率的重要因子,此法克服了革兰氏阴性菌菌粉不易制备和不耐保藏的瓶颈。

[Objective] This study aimed to prepare high viable count Pseudomonas putida bacteria powder, and improve the viability of drying and elongate the preservation period. [Methods] We selected cold blast drying technology to prepare bacteria powder, and optimized carriers and protective agents. [Results] Viability of drying was 65% on behalf of cold blast drying, which was significantly superior to spray drying （24%）. Carriers and protective agents with orthogonal experiments were applied to obtain optimal formulation of preparation bacteria powder. The result was as follows： as bacterial cell carriers, diatomite and corncob powder pretreated by Ammonia were mixed with ratio of 1：2.7% mannitol, 5% sodium glutamate and 1% glycerin were mixed as protectives （W/W）. Viable cell count was 1.03×10^11 CFU/g in instant preparation. The viability was 71.67% and 40.54% after 60 d storage at 4 ℃ and 30 d storage at room temperature （RT） respectively. [Conclusion] Cold blast drying had little damage to bacteria because of its relatively low temperature （10-40 ℃）. Corncob powder pretreated by Ammonia, mannitol and glutamate had positive effect on preservation of bacteria powder. This method was successfully applied to resolve the difficulties of long-term preservation of gramnegative non sporing bacteria.