耐铅解磷真菌联合磷矿粉钝化修复重金属铅

Immobilization recovery of heavy metal lead by lead-tolerance phosphate-solubilizing fungi combined with phosphate rock

解磷真菌从磷矿粉中释放的磷酸根离子是重金属铅(Pb)得以钝化修复的关键因子.本研究从福建省、海南省、台湾省三地的红树植物根际沉积物中筛选出4株兼具高效磷矿粉溶解能力和Pb耐受能力的耐Pb解磷真菌,分别为Penicillium sp.PSF-FJ1、Penicillium sp.PSF-TW、Aspergillus niger PSF-FJ3和A.aculeatus PSF-HN.它们在高浓度Pb溶液中都能存活,但高浓度Pb胁迫会不同程度地抑制菌株的解磷能力.在较低Pb污染水平(Pb质量浓度200 mg/L)时,保留或丧失解磷功能的4株菌株都可有效钝化水溶液体系中的Pb;但当Pb质量浓度达到800 mg/L时,只有保留磷矿粉溶解能力的菌株Penicillium sp.PSF-FJ1和Penicillium sp.PSF-TW才能有效钝化Pb.据此,利用Penicillium sp.PSF-FJ1和Penicillium sp.PSF-TW的解磷功能,将难溶性磷矿粉进行溶解后释放出其中的磷酸根离子,从而有效钝化溶液中铅离子,可为后续滨海湿地重金属修复提供新思路.

Soluble phosphate released by phosphate-solubilizing fungi(PSF)from phosphate rock is the pivotal factor in lead(Pb)immobilization.In this study,four Pb-tolerance PSF strains,which exhibited high phosphate rock-solubilizing capacity and metal Pb tolerance,were screened from the mangrove rhizosphere sediments in Fujian,Hainan and Taiwan provinces,China.These fungal strains were identified as Penicillium sp.PSF-FJ1,Penicillium sp.PSF-TW,Aspergillus niger PSF-FJ3 and A.aculeatus PSF-HN.These fungal strains could survive in highly concentrated Pb solutions;however,their phosphate-solubilizing ability could be inhibited under a high metal Pb stress.In an aqueous solution with 200 mg/L of Pb,four fungal strains,with or without phosphate-solubilizing capacity,could effectively immobilize the metal Pb.Nevertheless,only Penicillium sp.PSF-FJ1 and Penicillium sp.PSF-TW,which retained effective phosphate rock-solubilizing capacity,immobilized Pb effectively at 800 mg/L of Pb.Consequently,Penicilium sp.PSF-FJ1 and Penicilium sp.PSF-TW have great potential in the dissolution of mid-low grade phosphate rock,releasing the phosphate ion and subsequently immobilizing Pb ion in concentrated Pb solutions,which supplies new perspective for future recovery of heavy metal in coastal wetland.