Biogenic Amines Production in Mixed Culture of Lactic Acid Bacteria Isolated from Tucumán Wines
Silvana C. Ledesma, María Cristina Rubio, and Pedro A.
Aredes Fernández*
*Facultad de Bioquímica, Química y Farmacia, Ayacucho 471, San
Miguel de Tucumán/Tucumán/4000, Argentina
(pedroaredes@hotmail.com)
In a co-culture, microorganisms combine their metabolic activity to degrade and metabolize the substrates present in the environment. Just as there are symbiotic relationships, there is also competition that involves mechanisms of protection and antagonism. Lactobacillus paracasei AT45, isolated from wine, produces histamine and tyramine. These amines cause vasoactive and psychoactive effects in humans. Oenococcus oeni RAM10, a proteolytic microorganism, was selected as optimal to carry out malolactic fermentation. The objective of this work was to evaluate the interaction between O. oeni RAM10 and L. paracasei AT45 in pure and mixed cultures to establish a relationship with production of biogenic amines under winemaking conditions. The assays were carried out in commercial red wine inoculated with pure cultures of O. oeni RAM10 and L. paracasei AT45 at final concentrations of 107 cfu/mL and 103 cfu/mL, respectively, and in mixed culture at the same final concentration of both microorganisms. The trials were incubated at 23°C for 96 hr. Bacterial viability and production of histamine and tyramine were evaluated using a colorimetric method developed in our laboratory. In pure cultures, the viability of both microorganisms remained constant for all incubation times. In mixed culture, O. oeni RAM10 main- tained viability until 96 hr, while L. paracasei AT45 decreased growth to undetectable values. In pure culture, O. oeni RAM10 did not produce histamine or tyramine, while L. paracasei AT45 produced a concentration of 6.52 mg/L histamine and 3.57 mg/L tyramine at 96 hr. In mixed culture, no amine production was observed. These studies demonstrate that O. oeni RAM10 in mixed culture with a harmful bacterium causes a decrease in the concentration of biogenic amines.
Funding Support: Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
