三株具重金属抗性油菜内生真菌对镉铅锌富集特性研究

Bioaccumulation of Cd,Zn and Pb by three heavy metal-resistant endophytic fungi isolated from rapes

为了筛选到对重金属具良好富集活性的微生物吸附剂,以分离于大宝山矿区重金属富集植物油菜的3株具重金属抗性的内生真菌Fusarium sp.CBRF14,Penicillium sp.CBRF65和Alternaria sp.CBSF68为研究对象,分析了Cd、Pb和Zn的初始浓度对其活菌体的生物量、富集率及富集量的影响。研究结果发现,随着重金属初始浓度(试验设置的浓度范围内)的升高,Fusarium sp.CBRF14、Penicillium sp.CBRF65和Alternaria sp.CBSF68对Cd和Zn的富集率呈下降趋势,而对Pb的富集率则存在"先升高再下降"的过程;该3株内生真菌的生物量随着Cd、Pb和Zn初始浓度增加呈下降趋势,而对Cd、Pb和Zn的富集量则不断增加,它们对Cd的最大富集量介于20.5~53.4 mg·g^(-1),对Pb的最大富集量介于188.9~356.6 mg·g^(-1),对Zn的最大富集量介于28.4~292.8 mg·g^(-1)。研究结果表明这3株油菜内生真菌可在含重金属液体条件下生长并具有良好的重金属富集能力,其在重金属污染废水的生物修复中具有潜在的应用前景,同时也表明重金属耐性植物内生真菌是获得具重金属富集能力微生物的重要资源库。

The aim of this study was to select the effective microbial agents to remediate heavy metal pol-lutants by investigating the potential of the growing biomass of the three endophytic fungi through bioaccu-mulation to remove metals from contaminated water.In this study,three endophytic fungi Fusarium sp. CBRF14,Penicillium sp.CBRF65,Alternaria sp.CBSF68 tolerant Cd,Pb,and Zn were isolated from rapes growing in DaBao metal contaminated soils.And then we investigated the effects of initial metals （Cd,Pb and Zn）concentrations on the biomass,the metal bioaccumulation capacities and bioaccumula-tion percentages of the endophytic fungi.The results showed that the bioaccumulation percentages of Cd and Zn by CBRF14,CBRF65 and CBSF68 decreased with the increase of initial concentrations of Cd andZn in general,however,the bioaccumulation percentage of Pb by CBRF14 and CBSF68 showed a pattern of“increase-decline”.With the increase of the initial Cd,Pb,and Zn concentrations,the biomass of CBRF14,CBRF65 and CBSF68 showed the declined trend,but the bioaccumulation capacities of metals increased.The maximum bioaccumulation capacities of CBRF14,CBRF65 and CBSF68 were 20.5 ~53.4 mg·g^-1 for Cd,188.9~356.6 mg·g^-1 for Pb,and 28.4 ~292.8 mg·g^-1 for Zn,respective-ly.The results indicated that the three heavy metal-resistant endophytic fungi from rapes could live and accumulate metals in solutions with heavy metals,which suggested that they had the potential to remove heavy metals from metal-contaminated water.The results also indicated that plants accumulating multiple metals might harbor diverse fungal endophytes suitable for bioaccumulation of metals.