The Role Of Probioitics In Aquaculture
The growth of aquaculture as an industry has accelerated over the past decades; this has resulted in environmental damages and low productivity of various crops. The need for increased disease resistance, growth of aquatic organisms, and feed efficiency has brought about the use of probiotics in aquaculture practices. The first application of probiotics occurred in 1986, to test their ability to increase growth of hydrobionts (organisms that live in water). Later, probiotics were used to improve water quality and control of bacterial infections. Nowadays, there is documented evidence that probiotics can improve the digestibility of nutrients, increase tolerance to stress, and encourage reproduction. Currently, there are commercial probiotic products prepared from various bacterial species such as Bacillus sp., Lactobacillus sp., Enterococcus sp., Carnobacterium sp., and the yeast Saccharomyces cerevisiae among others.
Probiotics is a relatively new term which is used to name microorganisms that are associated with the beneficial effects for the host. Kozasa made the first empirical application of probiotics in aquaculture, considering the benefits exerted by the use of probiotics on humans and poultry. He used spores of Bacillus toyoi as feed additive to increase the growth rate of yellow tail, Seriola quinqueradiata.
However, certain probiotics have the ability to inhibit the growth of pathogenic bacteria. Moriarty determined the ability of Bacillus sp. to decrease the proportion of Vibrio spp. in shrimp ponds, especially in sediments. Further studies have stressed probiotics ability to stimulate appetite, improve absorption of nutrients, and strengthen the host immune system
