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enzymatically to the trandiol which can then form typical sail <br /> components such as hydroquinone, glucuronides or sulfonates. <br /> Under some circumstances , catechol may be formed by eucaryotic <br /> organisms including mammals , and degradation can then proceed via <br /> 3 the Ortho or meta cleavage pathway to complete microbial <br /> mineralization. Obviously, bacterial attack is preferred because <br /> of the complete degradation of the contaminant to CO2, water and <br /> j <br /> biomass (3). In subsurface soils , bacteria are known to be <br /> predominant. In fact , in studies reported on page 36, based on <br /> I colony type, only bacteria and possibly yeasts were detected in <br /> Lodi subsurface soils. <br /> • i <br /> The decomposition of the alkanes a alcohol dehydrogenase <br /> system (4) which feeds ini•o the be ox ation pathway. Many i <br /> bacteria . contain the necess sand a few are listed in E <br /> Table 3 .(3). This .aga.in 1 o mineralization of the I <br /> i <br /> contaminants. The ste i his pathway are oxidative; they <br /> require free oxygen. Thu ,:.both aromatic and .aliphatic <br /> degradation ars oxidative pathways requiring oxygen and <br /> f <br /> phosphorous (for energy production) and nitrogen for enzyme <br /> synthesis. <br /> i <br /> It has recently been shown that anaerobic degradation of toluene j <br /> i and benzene can occur. This process is slower and leads to the <br /> production of CO2 and methane along with undesirable phenol, <br /> I : cresols, or aromatic alcohols .(5). Thus, if oxygen is present, <br /> �r___T <br /> agaerob_i c _degradation w_i t 1_ be <br /> M1 neral zatian will proceed. <br /> -2I- r <br /> y� _ <br />