Aspergillus tubingensis介导植酸盐水解促进U(VI)-PO43-生物矿化

从广东某铀尾矿库水下沉积物中分离筛选出了一株能水解植酸盐的真菌M5-1，对其菌落形态、ITS序列、最适生长pH值、对铀的耐受性及其水解植酸盐的效果进行了分析，随后对M5-1生物矿化铀过程中pH值、正磷酸盐浓度、铀浓度、铀去除率的变化进行了监测，对矿化产物的主要元素和矿物组成进行了分析.证实了真菌M5-1为Aspergillus tubingensis（MH978623），其最适生长pH值范围为6~7，对铀（~0.84mmol/L）具有较强的耐受性；Aspergillus tubingensis介导植酸盐水解促进U（VI）-PO₄^3-矿化62d后，铀的去除率达95.2%；Aspergillus tubingensis介导U（VI）-PO₄^3-矿化过程中可能形成了难溶的氢铀云母和变钠铀云母矿物.结果表明，Aspergillus tubingensis能有效水解植酸盐释放可溶性正磷酸盐，从而促进U（VI）-PO₄^3-矿化.研究结果为采用Aspergillus tubingensis介导植酸盐水解原位修复铀污染地表水提供了试验依据.

Biomineralization of U(VI)-PO43- promoted by Aspergillus tubingensis mediated phytate hydrolysis

The fungus M5-1capable of hydrolyzing phytate was isolated from the sediments of a uranium tailings repository in Guangdong Province. Its colony morphology, ITS sequences, suitable growth pH value, tolerance against uranium and effect on hydrolysis of phytate were systematically studied. The variations of pH value, orthophosphate concentration, uranium concentration and removal efficiency of uranium were monitored. The main elements and mineral components of the biomineralization products were also analyzed. It was found that the strain M5-1was Aspergillus tubingensis (MH978623) with optimal growth at pH 6~7, and with high tolerance against uranium (~0.84mmol/L). After biomineralization of U(VI)-PO₄^3- promoted by Aspergillus tubingensis mediated phytate hydrolysis for 62days, the removal efficiency of uranium reached 95.2%. SEM-EDS and XRD analyses indicated that the insoluble chernikovite and metanatroautunite were formed during the biomineralization of U(VI)-PO₄^3-. The results showed that Aspergillus tubingensis could effectively hydrolyze phytate to release soluble orthophosphate, which promoted the mineralization of U(VI)-PO₄^3-. These results provided an experimental basis for the in-situ bioremediation of uranium contaminated surface water by biomineralization of U(VI)-PO₄^3- promoted by Aspergillus tubingensis mediated phytate hydrolysis.