BENEFICAL ASPECTS OF LACTIC ACID BACTERIA IN RANICULTURE

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

BIOCELL

Inca Ed.

Lugar: Mendoza; Año: 2007

0327-9545

Lactic acid bacteria (LAB) are widely distributed in many ecological niches in nature, and function also as probiotics. Raniculture is an increasing activity that implicates an intensive process which leads to the outbreak of infectious diseases, such as the red leg syndrome (RLS). The ethiological agents include Ps. aeruginosa, Enterobacteriaceae, and S. epidermidis. The sacrifice of non-helathy R. catesbeiana or the application of antibiotic therapies is frequent, which increase the production costs. Thus, probiotics are a novel alternative for the prevention and control of infections diseases in hatcheries. Some benefical porperties of LAB isolated from a local hatchery were studied. 170 LAB strains were able to inhibit the growth of the assayed pathogens by acidity, except Lactobacillus plantarum CRL 1606 that also inhibited the growth of RLS-related pathogens by H2O2. Food-borne bacteria were sensitive to organic acid produced, except S. aureus that 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 potentially in fish aquaculture.