Studies On The Structure Of Microbial Communities Of Multiple Heavy Metal Contaminated Sediment In Xiangjiang River And The Sediment Bioleaching

Understanding the ecosystem of heavy metal contaminated sediments is a key to bioremediate these sediments, which become a public concern with continuous development of modern industry. To investigate the bacteria community composition of heavy metal contaminated sediments in Xiangjiang River, total four sediment samples contaminated with multiple heavy metals were obtained and a culture-independent molecular approach, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was performed. The results revealed that heavy metal pollution affected microbial community diversity and the largest species dediversity appeared in the moderate polluted X sample. And the dominant family was a-Proteobacteria,β-Proteobacteria and Firmicutes in these sediments. And a-Proteobacteria signifcantly increased with the increasing of heavy metal, Redundancy analysis (RDA) analysis also confirmed this phenomenon.The sediment of Xiawan port was seriously polluted by heavy metals. Its was very special since the alkalinity and the high content of heavy metals. This study deals with bioremediation treatments of Xiawan port sediment contaminated by multiple metals with the mixed culture of auto-and heterotrophic bacteria. Bioleaching resulted in removal of heavy metals at higher levels, up to 95.3% Zn,94.2% Mn,90.1% Cu,84.4% Cd, but As, Hg and Pb were unsatisfactorily, the efficiency was 26.0%,15.9%, 19.9% respectively. And selective sequential extraction analyzed the changes in fraction of heavy metals before and after bioleaching demonstrating that distribution of the metal fractions varied widely in the original sediment and were mainly bound to organic associated forms and residual forms after bioleaching. These results open new perspectives for the bioremediation technology for the removal of heavy metals from highly contaminated sediments.