Resumen

GALLARDO, Adriana Alicia; RISSO, Susana; FAJARDO, María Angélica  y  ESTEVAO BELCHIOR, Silvia. Caracterización de polaciones microbianas presentes en la macroalga comestible Monostroma undulatum, Wittrock. ALAN [online]. 2004, vol.54, n.3, pp.337-345. ISSN 2309-5806.

    Characterization of microbial population present in the edible seaweed, Monostroma undulatum, Wittrock. The microbiological quality of Monostroma undulatum, Wittrock from the Southern Argentinean coast, was studied for its application for human food. Also the diversity and function of the native bacterial population to this green seaweed was analyzed. Samples were collected in Puerto Deseado, province of Santa Cruz, Southern Argentina (47º 45’L.S., 65º 55’L.W). The samples were analyzed for the presence of psycotrophic heterotrophic bacteria, marine heterotrophic bacteria, low nutritional request bacteria (LNRB), marine low nutritional request bacteria (LNRB marine), Vibrio spp, total and thermotolerant colifom bacteria, anaerobic sulfite reducing bacteria, yeasts and moulds. The isolates were identified using standard techniques based on morphologic, physiologic and metabolic characteristics. Among the gram-negative bacteria isolated, the predominant genera belonged to Vibrio (20%), E. coli inactiva (18%), Flavobacterium (11%), Flexibacter (9%), Moraxella (9%), Alcaligenes/Pseudomonas group (9%), Aeromonas (2%), Acinetobacter (2%). Cotophaga (2%), Photobacterium (2%), Ps/Caulobacter/Alteromonas/Spirillum group (2), The main genus of gram-positive bacteria was Staphylococcus. Were not detected human pathogenic bacteria. Focai contamination indicator bacteria were not isolated from fresh seaweed and seawater. These results showed an adequate microbilogical quality of seaweed acceptable for human food. The bacterial population associated to Monostroma undulatum, consisted of gram-negative, marine and psycotrophic microorganisms, including vibrios and enterobacteria as their main components. Also the identified bacteria showed a great capacity to hydrolyze different substrates and so they might contribute to the balance of this marine ecosystem.

Palabras clave : Nutritional resource; microbial population; Monostroma undulatum.