51
the process of decomposition of other microorganisms. Such results are
consistent to studies that indicate amino acids as the main nutrients of
Legionella ssp
. (Skaliy&McEachern , 1979:Fields
et al
, 1984; Yee&Wadowsky
, 1982; Lee &West ,1991; Rogers
et al
, 1994; Stout, Yu & Best, 1985).
Relation between
Legionella ssp
and Protozoa
Besides the
Legionella ssp
relation with other microorganisms in terms
of nutrients, the bacteriumis a facultative intracellular parasite of protozoan,
which confers it a greater resistance to adverse environmental factors.
Legionella
can multiply in several species of protozoa, and the main
ones are:
Acanthamoeba ssp, Naegleria ssp, Hartmanella ssp, Tetrahymena
pyriformis
and
Tetrahymena Vorax
.
Biofilm
Biofilm is the name given to an association of microorganisms that
live covered by a matrix of polymers that they produce. The association of
the microorganisms in biofilms forms a protective barrier for development,
narrowing the symbiotic relationships, thus favoring the development and
protecting those involved from hostile environmental factors.
The presence of biofilm greatly favors the development and survival of
Legionella ssp
in natural and artificial environments, due to the abundant
presence of nutrients and protozoan. The biofilm also facilitates the
attachment of the microorganisms in smooth surfaces. But, surfaces of
water systems that present corrosion with rough surfaces are even better
for the attachment of biofilm.
