TABLE 2 



Dynamics of BaP transformation catised by the Bering and 



Chukchi Sea waters microtlora in long in situ experiments 



(Auaiist 1488). 



4.3.2 Transformation of Poly chlorinated 



Biphenyls by Marine Bacterioplankton 



ALLA V. TSYBAN, SERGEI M. CHERNYAK, and GENNADIY V. PANOV 



Institute of Global Climate and Ecology. State Committee for Hydrometeorology and Academy of Sciences. Moscow. USSR 



Introduction 



Pollution of biosphere, the World Ocean, by xenobiotics 

 has become not only an ecological problem but a social 

 problem. In the postwar years, production of synthetic organic 

 compounds increased worldwide. In 1950, 7 million tons were 

 produced — by 1970,63 million tons, and by 1983. 230 million 

 tons(Geiss&Bourdeaux, 1986). At present, 5 million different 

 xenobiotics are produced by chemical manufacturers, with 

 fifty thousand being sold on the world market every year. No 

 iTiore than 10% of synthetic compounds (of the total amount 

 produced) are reportedly toxic and only twenty thousand 

 xenobiotics have been studied for genotoxic activity (Loprieno, 

 1981; Tanabe, 1983). 



Most investigated chlorinated hydrocarbons are PCB's 

 (Tanabe, 1983). This is due to wide application in industrial 

 and domestic materials, resistance to biodegradation and 

 bioaccumulation capability, acute toxicity, and unfavorable 

 effect upon reproductive processes in pelagic organisms. Also, 

 analytical techniques allow for reliable PCB determination in 

 most environmental samples. 



Current predictions (Bletchly. 1984) on the dynamics of 

 chlorinated hydrocarbons in the marine environment indicate 

 that chlorinated hydrocarbon concentration in the World Ocean 

 will increase 1.3-1.7 times by the year 2000. Because of the 

 production of new synthetic substances and accumulation in 

 the environment, scientists are interested in knowing the sources 

 and fates of xenobiotics. At present, the elimination of PCB's 

 from the environment occurs through photochemical oxidation 

 and microbial degradation. 



Aspects of PCB biotransfortiiation need further study. In 

 recent years, a great body of information has been ctiilected, 

 transformation of PCB's by individual strains of 

 microorganisms, relating to different systematic groups (Ahmed 

 & Focht, 1973; Sayler et cd.. \911: Furukawa et ai. 1978; 

 Furukawa et ai. 1979, 1983; Liu, 1980; Furukawa & 

 Chakrabarty, 1982; Furukawa, 1982; Brunner ef «/., 1985; 

 Unterman et ai. 1983; Bedard el ai, 1986; Bopp, 1986; 

 Bedard et ai. 1987a, 1987b; Kohler et ai. 1988). Many 

 bacteria have been shown toutilize PCB's as a source of carbon 

 and energy (Karasevich, 1982;Shieldst7a/., 1985). However, 

 not all PCB congeners are subject to microbial attack, which is 



95 



