26 Environmental Biotechnology
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(fat dropletfat dropletfat dropletfat dropletfat dropletFigure 2.7 Biosurfactants
amino acid, glutamate. Amino groups are highly conserved in all organisms due
to the small number of organisms able to fix atmospheric nitrogen and so the
source of an amino group is usually by transfer from another molecule. However,
eventually, nitrogen is removed by oxidative deamination and is excreted in a
form which depends upon the organism. Ammonia is toxic to most cells, but if
an organism lives in an aqueous habitat, it may release ammonia directly into its
surroundings where it is diluted and so made harmless. However, even in such
an environment, if dilution should prove insufficient, ammonia concentration will
increase, likewise the pH, consequently, the well-being of the organism will be
compromised. Organisms which cannot make use of dilution, rid themselves of
ammonia by converting it first into a less toxic form such as urea in the case of