Biology Reference
In-Depth Information
SUMMARY AND CONCLUSION
In general, Lactic Acid Bacteria have been proven to be the most promising
group of probiotic bacteria. This might be, in part, because the intestinal
microbiota of normal fi shes can be composed mainly by LAB and therefore
are able to colonize the exposed surfaces of epithelial cells (Ringo and
Gatesoupe, 1998) by adhering to the intestinal mucus (Jöborn et al., 1997).
These LAB have demonstrated to inhibit the colonization of the fi sh
intestinal mucus by pathogenic bacteria (Balcazar et al., 2008) and able
to produce inhibitory substances (Vazquez et al., 2005) that affect mainly
Gram-negative pathogens (Ringo and Gatesoupe, 1998). In shrimps, the
gut microbiota of healthy organisms is also composed by Gram-positives,
more than 75% of the taxa found by molecular methods in
Litopenaeus
vannamei
are members of the Firmicutes; a group that includes Bacillales
and LAB (Li et al., 2007). There are relatively few commercial products
available as probiotics that are useful in hatcheries, and many of these are
composed of LAB or
Bacillus
spp.
Future perspectives to consider for LAB research include evaluating
the permanence of the probiont within the host, mainly the ability
to colonize the host's intestinal tract and stay there for enough time to
prevent pathogen colonization. Also, the ability to be effective under
different external and internal conditions has to be estimated. Usually,
research has focused on evaluating the effi cacy of the probiont under
controlled laboratory conditions, but seldom at commercial facilities where
environmental parameters could fl uctuate greatly. Another area worth
studying is devising strain combinations that are capable of enhancing the
probiotic effect as compared to single strain formulations.
ABBREVIATIONS
BLIS
Bacteriocin-like inhibitory substances
LAB
Lactic acid bacteria
WSSV
White Spot Syndrome Virus
REFERENCES
Abelli, L., Randelli, E., Carnevali, O., Picchietti, S. (2009). Stimulation of gut immune system
by early administration of probiotic strains in
Dicentrarchus labrax
and
Sparus aurata
.
In: Trends in Comparative Endrocrinology and Neurobiology. H. Vaudry, E.W. Roubos,
G. Coast and M. Vallarino (eds). Ann. New York Acad.Sci., New York, USA pp. 340-342.
Abidi, R. (2003). Use of probiotics in larval rearing of new candidate species. Aquaculture
Asia 8:15-16.
Austin, B. and Brunt, J.W. (2009). The use of probiotics in aquaculture. In: Aquaculture
Microbiology and Biotechnology. Volume 1. D. Montet and R.C. Ray (eds). Science
Publishers, Enfi eld, New Hampshire, USA pp. 185-207.
