BENEFICIAL ASPECTS OF LACTIC ACID BACTERIA IN RANICULTURE

PASTERIS, S.E.; VERA PINGITORE, E.; ROIG BABOT, G.; BUHLER, M.I.; NADER-MACÍAS, M. E.

BIOCELL

Inca Ed.

Lugar: Mendoza; Año: 2008 vol. 32 p. 25 - 25

0327-9545

Lactic acid bacteria (LAB), which are widely distributed in many ecological niches in nature, can function as probiotics. Raniculture, a growing activity, entails an intensive process that leads to the outbreak of infectious diseases such as the red leg syndrome (RLS). Ethiological agents include Ps. aeruginosa, Enterobacteriaceae and S. epidermidis. Disposal of non healthy R. catesbeiana specimens or the application of antibiotic therapies is frequent, which increases production costs. Thus, probiotics are a novel alternative for the prevention and control of infectious diseases in hatcheries. Some benefical properties of LAB isolated from a local hatchery were studied. One hundred and seventy LAB strains were able to inhibit the growth of the assayed pathogens by acidity, with the exception of Lactobacillus plantarum CRL 1606, which also inhibited the growth of RLS-related pathogens by H2O2. Food-borne bacteria were sensitive to organic acid produced while S. aureus was also inhibited by H2O2. The strains produced low H2O2 concentrations in MRS+TMB+ peroxidase medium. Several Lactobacillus strains were hydrophilic. A similar behavior was observed in E. faecium strains. Lactococcus lactis inhibited the growth of Ps. aeruginosa and Listeria species by a combined effect of acidity, a class IIa bacteriocin and H2O2. From these studies we selected four L. plantarum strain; two P. pentosaceus strains and L. lactis CRL 1584 as probiotic candidates for raniculture and for potential use in fish aquaculture.