Effect of pH and temperature on the growth of vaginal probiotic Lactobacillus salivarius.

MARÍA SILVINA JUÁREZ TOMÁS; AÍDA PESCE DE RUIZ HOLGADO; MARÍA ELENA NADER-MACÍAS

Tafí del Valle, Tucumán, Argentina

Jornada; XVII Jornadas Científicas de la Sociedad de Biología de Tucumán; 2000

Sociedad de Biología de Tucumán

Lactobacilli control the vaginal microflora and pathogen inhibition through different mechanisms. In previous works, a probiotic L. salivarius subsp. salivarius CRL 1328, bacteriocin-like producer was selected. To include this microorganism in a pharmaceutical product, the optimal growth conditions to get a higher biomass in the shorter time is needed. The objective of the present work was to study the growth of L. salivarius at different pH and temperatures. L. salivarius, was inoculated at 2% in MRS and LAPTg broth. The growth was evaluated by spectrophotometry (OD at 540 nm) and pH measurements. The assayed pH were 5, 6.5 y 8, and the incubation temperatures 30, 37 and 44°C. Results: L. salivarius growth is higher in MRS than in LAPTg, showing an optimal growth at higher temperatures (37 and 44°C) and higher pH (6.5 y 8). In LAPTg, the growth is affected principally by the initial pH.  In MRS, a more buffered media, the temperature effect is higher. The lag phase is inversely related to temperatures. The growth rates are higher and the generation time shorter in MRS than in LAPTg, showing the same pattern in both media, with better conditions at neutral pH and higher temperatures. Conclusion:The optimal growth conditions of vaginal L. salivarius are: Culture media: MRS broth, Inoculum: 2%, Temperature: 37 to 44°C, initial pH: 6.5 to 8.