The word “probiotic” was introduced by Parker, 1974.
According to his original definition, probiotics are “organisms and substances which contribute to intestinal microbial balance”. Fuller, 1989
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revised the definition as “live microbiafeed supplement which beneficially affects the host animal by improving its intestinal microbial balance”. Therefore, several terms such as “friendly”, “beneficial”, or “healthy” bacteria are also commonly used to describe probiotics. Although application of probiotics in aquaculture seems to be relatively recent,
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the interest in such environment friendly treatments is increasing rapidly. Moriarty, 1998
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proposed to extend the definition of probiotics in aquaculture to microbial ‘‘water additives’’. A growing number of studies have dealt explicitly with probiotics, and it is now possible to survey its state of the art, from the empirical use to the scientific approach.
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