Biotechnology and Bioinformatics (1+1)

6.4.1 Introduction

The term, probiotic, simply means “for life”, originating from the Greek words “pro” and “bios”. The concept of probiotics was first popularized at the turn of the 20^th century by the Russian Nobel laureate Elie Metchnikoff.

Metchnikoff proposed that a normal, healthy gastrointestinal microflora in humans and animals provided resistance against “putrefactive” intestinal pathogens.

The word “probiotic” was introduced by Parker (1974) and defined as probiotics are “organisms and substances which contribute to intestinal microbial balance”.

Fuller (1989) revised the definition as “live microbial feed supplement which beneficially affects the host animal by improving its intestinal microbial balance”.

Although application of probiotics in aquaculture seems to be relatively recent, the interest in such environment friendly treatments is increasing rapidly. The use of microbial probiotics in aquaculture is now widely accepted.

At present, a number of probiotics are commercially available and have been introduced to fish, shrimp and molluscan farming as feed additives, or are incorporated in pond water. According to the claims of the producers, these products are effective in supporting the health of aquatic animals and are also safe. On the other hand, there are doubts with regard to the gene ral concept of probiotics and to these claims. Thus, there is clearly a need to increase our knowledge of intestinal microbiology and the effective preparation and safety evaluation of probiotics.