Application Of Bio-Toxicity Determination In Dredged Material

Ocean dumping is a rational choice to deal with waste that produced by humanmaterial production and social life that considering the limitation of the continentspace and the capacious of the ocean space. It reflects the environmental benefit ofthe marine space resource. However if there is no suitable management and scientificbio-toxicity determination measures, it will bring irreversible damage to oceanecological environment, although it is more economical to dispose of wastes intoocean than on land.This paper talked about the application of rapid bio-toxicitydetermination in dredged material to accurately evaluate the comprehensive toxicityand potential toxicity of typical dredged materials based on luminescent bacteria acutetoxicity test and DGE(Digital Gene Expression Profiling) technology,the result willprotect the marine environment and promote economic development. The mainresearch contents are as follows:1Application of bio-toxicity determination in dredged material based onluminescent bacteria acute toxicity test.A new microplate luminometry for the toxicity bioassay of environmentalpollutant with Photobacterium phosphoreum and Vibrio fischeri was developedreferring to method by use of photobacteria for detecting the Water quality-determination of the Acute Toxicity-Luminescent Bacteria Test (GB/T15441-1995).Effects of pH，reaction time and toxicity of cosolvent(DMSO).The results showedthat: A pH unit be between5-8is appropriate for both of Photobacteriumphosphoreum and Vibrio fischeri,and a15minute test is enough for the stabilizing ofreaction with a measurement of EC50. The cosolvent DMSO has a significantlytoxicity on Photobacterium phosphoreum and Vibrio fischeri, but none inhibitoryeffect when the volume fraction ratio is below1.5%. Nutrient salt sunc as N,P,C has aeliminated incentive effect in sample solution.Heavy Metal toxicities and organic pollutants toxicities of PCBs、DDT、BHC areassessed with Photobacterium phosphoreum and the dose-response curve for ZnSO4.7H2O, K2Cr2O7, HgCl2, CdCl2.2.5H2O,Na2HAsO4and Pb(NO3)2can bedescribed by Weibull model while for CuSO4.5H2O can be described by Logisticmodel in which the values of log2EC50were easily predicted. The Photobacteriumphosphoreum was most sensitive to Hg, followed by Zn, Pb,Cd, Cu,and the leastsensitive to Cr. The EC50of the Photobacterium phosphoreum fell within the scope ofthe species sensitivity distribution model predicted with other marine organisms.Organic pollutants PCBs,DDT,BHC has no significant toxicity to luminescentbacterial.The EC50of the Photobacterium phosphoreum fell within the scope of thespecies sensitivity distribution model predicted with other marine organisms.Compare to fish, daphnia, decapods and bivalves, Photobacterium phosphoreum is ata low level of sensitivity to Cu2+, but at higher levels of sensitivities to Cd2+, Pb2+,Hg2+, Zn2+and Cr6+. Most of the marine species have the same order of the responseto the six different heavy metals, indicating that Photobacterium phosphoreumtoxicity test is very important for predicting heavy metal effects in marine ecosystem.In this paper a sieris of bio-toxicity determination were taken using thi rapidmethod.As a result,comparing with the traditional method, there is no significantdifference between the two group of toxic test.2Application of bio-toxicity determination in dredged material based on DGEDigital Gene Expression Tag Profiling (DGE) technology was used to constructgene expression profile to screen differentially expressed genes.A large number ofimportant key regulatory Pathway genes of Ruditapes philippinarum on dredgedmaterials stress after48hs were obtained.14genes selected from expression profilingdata on the relative quantitative PCR verification analysis, And,these gene weresignificantly enriched GO functional gene cluster analysis and made significantenrichment Pathway statistical analysis of metabolic pathways. The main results areas follows:compared with the control group the low toxicity treatment group has a816up-regulated genes and1305down–regulated genes were differentially expressed,the higher toxicity treatment group has a200up-regulated genes and369down–regulated genes were differentially expressed. enriched GO and enriched Pathway analysis were conducted on differentially,including oxidation reduction process,oxidoreductase activity, extracellular region, NF-kappa B signaling pathway,Chemokine signaling pathway etc. Using real-time quantitative RT-PCR method toverify the two pathways significantly enriched in14differentially expressed genescritical to prove their differential expression levels consistent with the expressionprofile of sequencing results.