Bioremediation of Cesium-Contaminated Soil by Sorghum Bicolor and Soil Microbial Community Analysis

ABSTRACT

Growth and cesium accumulation in Sorghum bicolor was investigated using Cs-spiked soil (0, 40, 100, 200, 400 mg Cs/kg soil) during the entire growth period (139 days). The results showed that higher soil Cs concentrations increased Cs uptake by S. bicolor. The Cs content in stems, leaves and roots correlated well with soil Cs concentration, following an exponential or linear pattern (R² > 0.92). When the Cs level was 40, 100, 200, 400 mg/kg soil, the average Cs concentration in roots reached 3.84, 43.77, 76.95, 258.49 mg/kg DW, in stems it reached 7.04, 6.12, 27.57, 167.41 mg/kg DW, in leaves it reached 4.23, 4.52, 46.09, 181.70 mg/kg DW, and in shoots it reached 6.09, 5.61, 35.12 and 172.27 mg/kg DW, respectively. The Biolog Eco-plate assay showed that Cs enhanced soil microbial diversity and activity. Microbial community level physiological profiles (CLPPs) were sensitive to Cs and therefore can be used for rapidly assessing soil microbial community activity levels under Cs stress.

KEYWORDS:

• Bioremediation
• cesium
• contaminated soil
• microbial community analysis
• Sorghum bicolor

Funding

The research was supported by the Program for Changjiang Scholars and Innovative Research Team in University (IRT-13026) and the National S&T Major Project (2013ZX06002001). The authors also appreciate the financial support provided by the Open Research Fund Program of Key Laboratory of Advanced Reactor Engineering and Safety, Ministry of Education of China, and the National Natural Science Foundation of China (Grant No. 51338005).