Recent A dvances on Lipid Biomarkersin Marine Sediments

LI Xiao-lin

(Environmental Science and Engineering,Qingdao University,Qingdao Shandong 266071,China)

0 Introduction

1)Biomarkers

Biomarkers refer to some unnormal signal indicators produced by organisms which are damaged in the lever of molecular,cellular,individual or population because of environmental contaminants.As the rapid development of molecular biology theory,both of domestic and foreign have payed attention to the study of biomarkers[1].In 1987,National Academy of Sciences firstly defined biomarkers as changes of components,process,structure or function of cytological or biochemicalan which can be measured from an organism or sample,those changes are resulted from some external compounds[2].Then,Benson and DiGiulo[3]believe individual organism can produce sublethal effects when it is exposed to environmental contaminants,during this process,some biochemical,physiological or pathological reactions will emerge,they note this reactions which could be detected in individual organism as biomarkers.Bioindicators are first proposed in the 1970’s pollution ecology.An ideal biomarkers should have the figures of chemical specificity,determination of trace amount,low cost of test,rapid test,and the correlation with the amount of contaminants in environmental samples.

2)Establishment and study history of marine biological markers

Biomarkers have indicative effect because they have some association with biological structures of biogenic predecessor.With the advancement of modern analytical techniques, particularly the development of chromatography -mass spectrometry technology.Technology of biomarkers become more and more mature,which provides more detailed information for the study of organic matter source and chemical conversion in biogeochemical systems.Biomarkers was first used as a tracer substance in the fuel of geochemical studies,Treibs first reported the relationship of chlorophyll-a of organisms and porphyrin of oil and oil shale,and thus firstly proposed the evidence of oil sources[4].Later,many biomarkers(such as n-alkanes,isoprene,hopane,terpanes,steranes,etc.)are applied successively,providing a source of organic and environmental conditions during the process of deposition and burial(diagenesis),etc.

Currently,a variety of useful biomarkers has been developed,they have been used in wide range of early diagenetic,degradation of organic,ancient marine environment,change of ancient climate,even in item of environmental protection.Marine biomarkers are natural organic compounds from the ocean autogenous or terrestrial input,such as sterols,fatty acids,non-aromatic hydrocarbons and polycyclic aromatic hydrocarbons.These molecular of markers,can be called marine biomarkers,often used as an indicator in the study ofmarine biogeochemical process due to their stability of chemical properties and diversity of molecular structure[5].Early in the 1970s,biomarkers have began to be applied in marine sediment[6],since then,marine sediments developed rapidly.Studies have shown that organic in the ocean comes from the primary productivity of marine phytoplankton,terrigenous input perhaps take a account for less than 1%in total input.Some scholars took biomarkers to rebuild the population structure of phytoplankton and primary productivity in the individual sea.Some other scholars studied the surface temperature of ancient ocean,salinity,pH,etc.through characteristic biomarker[7].In conclusion,the study of biomarkers are widely carried out.

1 Research prospects of biomarker in marine sediments

Ocean biomarker is widely used in pigments and lipids,and pigment is mainly used for the determination of algae’s biomass and community composition.Biomarkers of Lipid,such as n-alkanes,alcohols ketones,fatty acids,etc.,have formed some research methods.The application of ASE accelerated extraction technology significantly narrow the period of experiment,more comprehensive and systemic methods are developing.Consider the importance of biomarkers to biological origin and environmental monitoring,study of more stable lipid biomarkers will be the focus of future.

［1］Vader Oost R,Beyer J,Vermeulen N P E.Fish Bioaccumulation and Biomarkers in Environmental Risk Assessment a Review [J].Environmental Toxicology and Pharmacology,2005,13:57-149.

［2］National Research Council. Committee Vanon Biological Markers[J].Environmental Health Perspective,1987.1987(74):3-9.

［3］Benson W H,Di Giulio R T.Biomarkers Asessments of Contaminated Sediments Toxicity Assessment[C].Publishers,1992：241-265.

［4］TreibsA.Chlorophyll and haemin derivatives in organic materials[J].Angewandte Chemie,1936,49:682-686.

［5］Xin Yu.A Primary study on the fatty acid as biomarker and its application in the study of bacteria’s role in the nutrients interface exchange Proeess at the area of HAB high-frequency-occurrence in East China Sea(ECS)[D].Chemistry and Chemical Engineering,Ocean University of China,Qingdao，2005.

［6］Albaiges J,Albrecht P.Fingerprinting marine pollutant hydrocarbons by computerized gas chromatography-mass spectrometry[J].International Journal of Environmental Analytical Chemistry,1979,6:171-190.

［7］Schulte S,Bard E.Past changes in biologically mediated dissolution of calcite above the chemical lysocline recorded in Indian Ocean sediments[J].Quaternary Science Reviews,2003,22(15-17):1757-1770.