Pseudomonas P.lb402 Use The Degradation Of Pcbs, Non-ionic Surfactant Tween-80,

The recent studies related bioremediation of soils contaminated by polychlorinated biphenyl (PCBs) are of increasing concern in environmental biological engineering area. In our group, an idea is presented that surfactant is used as the solubilizer of PCBs and the sole carbon source to enhance the bioremediation of soils contaminated by PCBs. Non-ionic surfactant Tween-80 was screened out to act as the solubilizer of PCBs and the sole carbon source of Pseudomonas LB402 in our pre-study. In this study, the effect of using Tween-80 as growth substrate on co-metabolic degradation of PCBs is investigated in-depth on the base of pre-study. The results are as following. (1) Compared to the resting-cell system, biodegradation rate of PCBs is enhanced obviously while P.LB402 is growing on the carbon source of Tween-80. The same concentration of 2,3 ,4,4 - tetrachlorobiphenyl(0.82ug/mL) was biodegraded between in resting-cell system and in growing-cell system. The biodegradation rate of 2,3 ,4,4 - tetrachlorobiphenyl is 31.3% at 52 hours in the former and 60.1% at 48 hours in the latter. (2) Biodegradation rate of PCBs is enhanced by increasing the concentration of Tween-80. The biodegradation of 2,3 ,4,4 -tetrachlorobiphenyl is investigated with the different concentration of Tween-80. The biodegradation rate is 67% at 60 hours with 3g/L of Tween-80. At the same time, the biodegradation rate is 41% with 1g/L of Tween-80. (3) Concentration of PCBs has an effect on the biodegradation rate of PCBs. In spite of in resting-cell system and in growing-cell system, the concentration of PCBs is bigger and the biodegradation rate of PCBs is faster. (4) P.LB402 can bio-transform PCBs congers above six chlorines. Biodegradation rate of lower-chlorinated congeners is bigger than those of higher-chlorinated congeners. In growing-cell system, the biodegradation rates of Aroclorl242,1254,1260 are 44%, 27.3%, 9.7% respectively. Therefore the conclusion is drawn that nonionic surfactant Tween-80, taken as carbon sourceand desorption, can improve the biodegradation efficiency of PCBs.