Dan Su, Yu Pu

School of Environment, Liaoning University

ChunJuan Gong

Chinese Academy of Sciences

Zhenli He

Indian River Research and Education Center

Abstract

There are large areas of contaminated soils with low- and medium-concentration of polycyclic aromatic hydrocarbons (PAHs) in the coldest regions of the earth, potentially threatening ecological safety and human health. Using maize cobs (MC) as the carrier, two cold-adaptive PAHs-degrading microorganisms, bacterial (Pseudomonas sp., SDR4) and fungal (Mortierella alpine, JDR7) strains were co-immobilized. The degradation characteristics of phenanthrene (Phe), pyrene (Pyr) and benzo[a]pyrene (BaP) in freeze-thawed soil by both co-immobilized and free microorganism were studied. The removal rate of Phe, Pyr and BaP using the co-immobilized fungal-bacterial consortium within 60 d was 59.2±3.7%, 46.6±3.3%, and 36.8±2.7%, respectively, which was obviously higher than that of free fungal-bacterial consortium in the same time. Ten percent (w/w) was the optimal amount of inoculum for PAH degradation in the co-immobilized fungal-bacterial consortium. Under low-temperature conditions, when the initial concentration of PAH was between 10-100 mg•kg−1, the immobilized cold-adaptive fungalbacterial consortium displayed the desired degradation of PAHs. The scanning electronic microscope (SEM) observation and mass transmission showed that the microstructure of co-immobilized mixed system was beneficial to the growth of SDR4 and JDR7 at low temperature. These results imply that the cold-adaptive fungal-bacterial consortium, co-immobilized on MC, has the potential for application in remediating PAH contaminated soil under the freeze-thawing environment.

Read the article here:   16-Application of cold-adaptive Pseudomonas sp. SDR4 and Mortierella alpina JDR7 co-immobilized on maize cob in remediating PAH-contaminated freeze-thawed soil.pdf