发光菌冻干粉保护剂及贮藏效果的研究

Effect of Lyophilization Protectants and Storage Conditions on Stability of Lyophilized Bioluminescent Bacteria

探究脱脂乳类复合保护剂在冷冻干燥过程中对青海弧菌Q67(V.qinghaiensis sp.-Q67)和明亮发光杆菌T3(P.phosphoreum sp.-T3)相对发光率的影响,并对保护剂进行优化;-20、4℃以及室温(16～25℃)条件下对两种发光菌冻干粉的贮藏效果进行比较研究。结果表明:明亮发光杆菌T3对冷冻干燥的抗性要高于青海弧菌Q67;3种保护剂中,以脱脂乳、蔗糖、壳聚糖混合物为保护剂的两种发光菌粉复苏30min后的发光度最高;以脱脂乳、蔗糖、壳聚糖、谷氨酸钠混合物为保护剂的青海弧菌Q67菌粉在-20℃条件下长期贮藏效果最好;而对明亮发光杆菌T3菌粉长期贮藏而言,3种保护剂在-20、4℃和室温条件下的效果均较好。这两种菌粉在30min内快速反应,表明它们在毒性物质快速检测中有着较好的应用价值。

Abstract： This study was designed to examine the effect of different lyophilization protectants based on skim milk and storage conditions （-20, 4 ℃ or room temperature, 16-25℃, and different periods of time） on the relative luminous efficiency of lyophilized cells of E qinghaiensis sp.-Q67 and P. phosphoreum sp.-T3. The results showed that P. phosphoreum sp.-T3 had better tolerance than E qinghaiensis sp.-Q67 during the freeze-drying process. After 30 min of recovery, the lyophilized cells of both strains with a mixture of kim milk, sucrose and chitosan as the protectant showed the highest luminous efficiency. The best temperature was -20 ℃ for long-term storage of E qinghaiensis sp.-Q67 lyophilized with a protectant composed of skim milk, sucrose, chitosan and sodium glutamate. P. phosphoreum sp.-T3 lyophilized with any one of the three protectants investigated had good stability during long-term storage irrespective of -20, 4 ℃ or room temperature. Both lyophilized strains could react within 30 min, indicating their potential application in rapid toxicity tests.