Application of buoyant marine cyanobacteriaon to eco-monitoring

本研究以携带环境刺激-反应元件报告基因的海洋浮游蓝藻为研究对象，采用蔗糖梯度法对海洋浮游蓝藻进行了筛选。为了构建用于环境监测的重组蓝藻，我们从一株海洋蓝藻中分离了刺激-反应元件（刺激诱导启动子及其调控区）。利用带有luxAB基因的穿梭载体pSRL 4作为报告基因，通过其微型基因组文库对聚球藻进行了研究。从181个重组菌株中筛选得到3个刺激-响应型蓝藻克隆，其中1个克隆对UVA敏感，2个克隆对NaCl敏感。测序分析表明，这些克隆具有转录控制区和启动子，表明利用上述报告蓝藻和漂浮系统可以实现对多种环境影响的生态监测

This study aimed to construct a monitoring system for environmental toxic factors employing buoyant marine cyanobacteria harboring a reporter gene with environmental stimulus-response elements.Marine cyanobacteria from our culture collection were screened for buoyancy using the sucrosegradient method. Furthermore, floating culture system for marine cyanobacreria was also constructed using buoyant coal-ash materials.In order to construct recombinant cyanobacteria for environmental monitoring, we isolated stimulus-response elements (the stimulus-inducible promoter and its regulator region) from a marine cyanobacterium. Synechococcus sp. through its mini-genomic library using the shuttle vector pSRL4 with luxAB genes as a reporter. Three stimulus-response cyanobacterial clones were obtained from 181 recombinant clones where one clone for UVA responsive and two clones for NaCl. Furthermore, several strong promoters were also found. Sequencing analysis showed that these clones had transcriptional control regions and promoters.These results shows that eco-monitoring for several environmental impacts could be achieved by using above reporter cyanobacteria and floating system