Biodegradation of Crude Oil in Contaminated Soils by Free and Immobilized Microorganisms  

作　　者：WANG Zhen-Yu XU Ying WANG Hao-Yun ZHAO Jian GAO Dong-Mei LI Feng-Min B. XING 

机构地区：[1]College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100 (China) [2]College of Animal Science and Veterinary Medicine, Qingdao Agricultural University, Qingdao 266109 (China) [3]Chemical and Mineral Metal Material Testing Center, Tianjin Entry-Exit Inspection and Quarantine Bureau, Tianjin 300456 (China) [4]Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst MA 01003 (USA)

出　　处：《Pedosphere》2012年第5期717-725,共9页土壤圈（英文版）

基　　金：the National Natural Science Foundation of China (No.41073067);the Key Program of the Ministry of Education,China (No.308016);the National Major Special Technological Programme Concerning Water Pollution Control and Management of China (No.2009ZX07010-008)

摘　　要：The efficiencies of free and immobilized bacterial cultures of petroleum hydrocarbon degraders were evaluated and compared in this study. Hydrocarbon-degrading microbial communities with high tolerance to and high degrading ability of crude oil were obtained from the soil contaminated with crude oil in the Yellow River Delta. Then, the microbial cells were immobilized in sodium alginate （SA） beads and sodium Mginate-diatomite （SAD） beads. The biodegradation of crude oil in soil by immobilized cells was compared with that by free cells at three inoculation concentrations, 1× 104 colony forming units （cfu） kg-^（-1）（low concentration, L）, 5 × 104 cfu kg^（-1） （medium concentration, M）, and 1× 105 cfu kg^（-1） （high concentration, H）. At 20 d after inoculation, the maximum degradation rate in the immobilized systems reached 29.8% （SAD-M）, significantly higher （P 〈 0.05） than that of the free cells （21.1%）, and the SAD beads showed greater degradation than the SA beads. Moreover, both microbial populations and total microbial activity reached significantly higher level （P 〈 0.05） in the immobilized systems than free cell systems at a same initial inoculation amount. The scanning electronic microscope （SEM） images also confirmed the advantages of the immobilized microstructure of SAD beads. The enhanced degradation and bacterial growth in the SAD beads indicated the high potential of SAD beads as an effective option for bioremediation of crude oil-contaminated soils in the Yellow River Delta.The effciencies of free and immobilized bacterial cultures of petroleum hydrocarbon degraders were evaluated and compared in this study. Hydrocarbon-degrading microbial communities with high tolerance to and high degrading ability of crude oil were obtained from the soil contaminated with crude oil in the Yellow River Delta. Then, the microbial cells were immobilized in sodium alginate (SA) beads and sodium alginate-diatomite (SAD) beads. The biodegradation of crude oil in soil by immobilized cells was compared with that by free cells at three inoculation concentrations, 1 × 104 colony forming units (cfu) kg-1 (low concentration, L), 5 × 104 cfu kg-1 (medium concentration, M), and 1 × 105 cfu kg-1 (high concentration, H). At 20 d after inoculation, the maximum degradation rate in the immobilized systems reached 29.8% (SAD-M), significantly higher (P < 0.05) than that of the free cells (21.1%), and the SAD beads showed greater degradation than the SA beads. Moreover, both microbial populations and total microbial activity reached significantly higher level (P < 0.05) in the immobilized systems than free cell systems at a same initial inoculation amount. The scanning electronic microscope (SEM) images also confirmed the advantages of the immobilized microstructure of SAD beads. The enhanced degradation and bacterial growth in the SAD beads indicated the high potential of SAD beads as an effective option for bioremediation of crude oil-contaminated soils in the Yellow River Delta.

关 键 词：bacterial growth degradation rate hydrocarbon degraders immobilized cells sodium alginate-diatomite beads 

分 类 号：X703[环境科学与工程—环境工程] X172