BIOL 360 Lecture Notes - Lecture 19: Cometabolism, Microbial Ecology, Cyclohexanol
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Vertical soil zonation: thin oxic zone (aerobic respiration, narrow zone of nitrate reduction, zone of sulfate reduction- sulfate=electron acceptor, methanogenesis- reducing co2- archaea. Co2 + 2h2a + light (ch2o) + h2o + 2a upon cometabolism, for example during nitrification where nitrate reducers form nitrite which can then be reduced further by other species. In some examples of cometabolism certain microbes cometabolically oxidize a second substrate, while growing on a favored substrate, to form a product(s) that can be degraded by a different microbe. According to a strict definition of cometabolism, the second substrate is not assimilated by the primary organism, but the oxidation products are available for use by at least one other microbial population. In lab i gave you the example of mycobacterium vaccae, which uses an enzyme (alkane monoxygenase) to oxidize propane. Accidentally, this enzyme also oxidizes, at no additional cost for m. vaccae, cyclohexane into cyclohexanol. Thus, cyclohexane is co-metabolized in the presence of propane.
