Bacillus sp.Z2对稀土钇的固定及阻控水稻吸收效应

Bacillus sp.Z2 immobilized rare earth yttrium and reduced the absorption of Y in rice.

本文从赣南稀土矿区分离获得一株耐钇(Y)的根际植物促生细菌Z2,初步鉴定为芽孢杆菌属细菌,摇瓶发酵条件下能够有效减少Y3+生物有效性,其作用机理可能是菌体吸附、pH值升高以及活性代谢产物与Y3+结合的共同作用.水稻砂培过程中添加Z2菌能够显著减少水稻根部Y的积累:0.08mmol/L处理条件下减少49%(P<0.05),0.35mmol/L处理条件下减少43%(P<0.01).植物螯合肽响应水稻根部积累的稀土钇,金属硫蛋白和谷胱甘肽转硫酶无明显变化.研究结果表明Z2菌可作为潜在的菌种资源,在细菌修复稀土污染农田和保障水稻安全生产中应用.

A rhizosphere growth-promoting bacterium Z2 resistant to yttrium(Y)was isolated from the rare earth mining area in southern Jiangxi Province.It was identified as Bacillus sp.,which could effectively reduce the bioavailability of Y3+under shake-flask fermentation.The mechanism may be the combined effect of bacterial adsorption,pH increasing and active metabolite which can bind with Y3+.In pot experiment,Z2 could significantly reduce the accumulation of Y in rice root by 49%(P<0.05)and 43%(P<0.01)under 0.08 and 0.35mmol/L Y3+treatment conditions,respectively.Phytochelatin was responsive to the increase of yttrium content in rice roots,metallothionein and glutathione s-transferase did not change significantly.The results indicated that Z2 could be used as a potential strain resource in the remediation of rare-earth contaminated farmland and in the safe production of rice.