煤矿区土壤FDA活性测定及优化

Determination and optimization of FDA activity on coal mining area soils

针对煤矿区被污染土壤中微生物活性低、种群结构相对单一和污染物胁迫等特点,对其土壤微生物的荧光素双醋酸脂（FDA）活性测定的关键步骤进行探讨和优化。结果表明,在煤矿区污染土壤的FDA活性测定过程中,培养时间选择30 min符合活性反应线性范围并适宜试验测定,以氯仿和甲醇（V（氯仿）∶V（甲醇）=2∶1）作为终止剂,用量为5 mL时可以经济、有效终止反应,离心时间为10 min时达到最大吸光值。以单位时间荧光素浓度来表征和规范FDA活性的单位,可为不同矿区土壤样品及污染土壤修复过程中的微生物活性测定与比较提供依据。矿区土壤FDA活性较低,仅为有机污染土壤生物修复反应土壤的5%~10%,可能对其生物修复产生一定制约,应加强针对性调控。

The key steps parameters of microbial fluorescein diacetate（FDA） activity measurement method is discussed and optimized according to the low microbial activity,unitory population structure and the stress due to the contamination by metal and organic matter in coal mining area.The microbial cultivation and analysis indicate that the absorbency is directly related to the cultivation time,and 30 min is determined combined the liner discipline and plenteous reaction.The volume of chloroform and methanol ratio is 2∶1 mixing stopping agent（5 mL） is selected to terminate the reaction rapidly,effectively and economically.The following centrifugal experiment of stopped reaction system show that the maximum absorbency is obtained after centrifuged for 10 min.At last,the FDA activity is determined as the concentration of fluoresceine converted by specification curve,which could provide convenient microbial activity comparing way and reference to soil samples in different coal mining areas as well as the remediation of polluted soil layer.The analyzing results show that FDA activity in coal mining area is just only 5%~10% of the high activity ones,so the coal mine should strength regulate and control.