Synthetic plastics are
A) oxidized completely to carbon dioxide after a few years under aerobic conditions.
B) partially degraded into branched chain and polyaromatic hydrocarbons.
C) degraded slowly under anoxic conditions.
D) extremely recalcitrant to microbial degradation.
Microbial plastics are composed of
A) polysaccharides.
B) polyhydroxyalkanoates.
C) polyaromatic hydrocarbons.
D) xenobiotics.
Which of the following hydrocarbon compounds are MOST recalcitrant?
A) straight-chain hydrocarbons
B) ethane
C) polycyclic hydrocarbons
D) propane
Reductive dechlorination is important in the breakdown of chlorinated xenobiotics because
A) anoxic conditions develop rapidly in polluted habitats.
B) oxygen is not present in most soils.
C) aerobic breakdown of xenobiotics is not possible.
D) only cometabolism occurs aerobically.
Microbial immobilization is the best strategy for uranium bioremediation, because
A) uranium is difficult to chemically oxidize.
B) uranium contamination is widespread and thus difficult to physically remove.
C) the by-products of chemical immobilization are toxic.
D) immobilization may only be temporary.
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