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					Uses of Bacteria in Bioremediation
Emer Colleran


1. introduction
    Bloremediation      has been defined as a “biological response to environmental
 abuse” (I) This definmon serves to distmguish between the use of mtcroorgan-
 isms to remediate         contammated      sites and their application       m biotreat-
ment/biorecycle        processes designed         to reduce organic and morganic
contaminant emissions at source. This chapter will focus on the former while
recognizing that biologrcal treatment processes currently play a major role m
preventing and reducing the extent of organic and inorganic environmental con-
tamination from the Industrial, agricultural, and municipal sectors
    Bioremedlation      is concerned with the biological restoration of historically
contaminated sites and with the cleanup of areas contaminated in more recent
times, either accidentally or incidentally, as a result of the production, storage,
transport, and use of organic and inorganic chemicals (1,2).
    Much of our inherited legacy of environmental            contamination  can be traced
back to industrial, municipal,        and military waste management practices that
advocated disposal rather than treatment (1,3). In many cases, the degree of site
contammation was exacerbated by the decline m competitiveness of an industry
(e.g., coal gas manufacture) or by the nonexistence or ineffective enforcement
of environmental      protection legislation.
    Current legislation and recent waste management practices place a heavy
emphasis on waste mmimization,            reuse, recycle, and treatment, with disposal
being the final and least preferred option Nevertheless, the huge increase over
the latter half of this century m the production and use of xenobiotic chemicals
has created new sites of environmental          contamination    whose restoration is fur-
ther complicated by the fact that many of these xenobiotics are persistent or
recalcitrant to microbial        breakdown (4). The persistence of anthropogemc
                    From    Methods III B~otecbnology,       I/o/ 2 Bofemed~ahon      Protoco/s
                           E&ted by D Sheehan          Humana     Press Inc , Totowa,   NJ


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