高效絮凝菌EbZL-1的筛选鉴定及采收微藻效果评价  

Screening and Taxonomic Characterization of the Efficient Flocculating Bacterium EbZL-1 and Its Application in Microalgae Harvesting

作　　者：赵佳宇 吕梁彧 韩小玥 闫宇飞 丁范 关心 张云龙[1] ZHAO Jiayu;LYU Liangyu;HAN Xiaoyue;YAN Yufei;DING Fan;GUAN Xin;ZHANG Yunlong(College of Biological Science and Medical Engineering,Donghua University,Shanghai 201620,China)

机构地区：[1]东华大学生物与医学工程学院,上海201620

出　　处：《Journal of Donghua University(English Edition)》2024年第1期46-56,共11页东华大学学报（英文版）

基　　金：Foundation of Shanghai Science and Technology Committee,China(No.19410741800)。

摘　　要：从东华大学镜月湖底淤泥样本中筛选到一株高效絮凝菌,采用16S rDNA测序和菌种鉴定试剂盒确定该菌株属于肠杆菌属(Enterobacter),命名为EbZL-1。以高岭土悬液为待絮凝标准液,通过单因素试验和响应面法探究絮凝菌EbZL-1在不同影响因素下的絮凝能力。研究结果表明:以11.69 g/L葡萄糖为碳源,1.04 g/L硝酸铵为氮源,培养基pH=7.8,摇床转速为160 r/min,菌株接种量为45μL(1.2×10^(5)CFU/mL),培养12 h,EbZL-1达到对数生长期;Ca^(2+)作助凝剂,高岭土悬液pH=7.0时,10 min内EbZL-1絮凝率可达96.6%,优于商用絮凝剂聚合氯化铝(120 min,95.0%)。进一步探究菌株絮凝机制,结果表明EbZL-1通过菌体自身紧密吸附待絮凝物实现大颗粒快速沉降。利用EbZL-1沉降小球藻,5 min内其絮凝率高于95%,油镜观察絮凝后小球藻,其胞体未受损。与现有絮凝菌比较,EbZL-1在广泛的pH范围(pH=5~10)内,均可快速沉降微藻,在微藻采收工艺中具有应用前景。EbZL-1絮凝菌不仅有望提升微藻采收效率,且在污水处理等方面也有应用价值,值得进一步开发。Microalgae are a type of photosynthetic cellular factory capable of efficient CO_(2) capture,biofuel production and wastewater treatment.However,the large-scale harvesting of microalgae still faces technological bottlenecks,and microbial flocculation has distinct advantages.In this study,a highly efficient flocculating bacterium named EbZL-1 is screened from the sediment samples of Jingyue Lake at Donghua University.It is identified as Enterobacter through 16S rDNA sequencing and a strain identification kit.The flocculation ability of EbZL-1 is tested through single-factor and multifactorial analysis experiments by using Kaolin suspension as standard flocculating liquid.The results show that the flocculation rate of EbZL-1 can reach 96.6%within 10 min,which is superior to that of the commercial polyaluminum chloride(95.0%,120 min).The optimal culture conditions for the bacterium to achieve the above flocculation rate are a carbon source of 11.69 g/L glucose,a nitrogen source of 1.04 g/L ammonium nitrate,a medium pH value of 7.8,a shaker rotation speed of 160 r/min,an inoculation amount of 45μL(1.2×10^(5)CFU/mL),and a culture time of 12 h to reach the logarithmic growth phase.The optimal flocculation conditions are Ca^(2+)as a flocculant aid with the pH value of the Kaolin suspension being 7.0.In the flocculation and sedimentation experiment of chlorella,the flocculation rate of EbZL-1 is higher than 95%,and the chlorella cells after flocculation are found to be undamaged upon inspection,demonstrating the advantages of the microbial flocculation technology.Further investigation into the mechanism of flocculation reveals that EbZL-1 can complete the rapid sedimentation of large particles by tight adsorption.In summary,the flocculating bacterium EbZL-1 has application value in the large-scale harvesting of microalgae and wastewater treatment.

关 键 词：微藻采收 生物絮凝 絮凝菌 微生物絮凝剂 肠杆菌属 

分 类 号：Q93[生物学—微生物学]