Microcalorimetric study of the growth of Enterococcus faecalis, Pseudomonas aeruginosa and their mixtures in an enriched culture medium

• Published in: Journal of thermal analysis and calorimetry 2015-07, Vol.121 (1), p.463-468
• Main Authors: Vazquez, C., Lago, N., Mato, M. M., Legido, J. L., Esarte, L.
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Bacteria; Chemistry; Chemistry and Materials Science; Growth; Hostages; Inorganic Chemistry; Measurement Science and Instrumentation; Physical Chemistry; Polymer Sciences; Pseudomonas aeruginosa
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-015-4606-0

Microcalorimetry is a highly sensitive experimental technique that allows to determine the energy released by any process or transformation. In the field of medicine, it is interesting for investigations of microbial processes. The interaction relationship between Enterococcus faecalis and Pseudomonas aeruginosa was researched using a Tian–Calvet calorimeter equipped with two stainless steel cells (reference and experimental). Three samples from both bacteria were prepared in the following proportions: 20 + 80 % (0.2 mL E. faecalis  + 0.8 mL P. aeruginosa ), 50 + 50 % (0.5 mL E. faecalis  + 0.5 mL P. aeruginosa ) and 80 + 20 % (0.8 mL E. faecalis  + 0.2 mL P. aeruginosa ). Experiments were carried out at a concentration of 10 3  CFU mL −1 and a constant temperature of 309.65 K. Recording the heat voltage difference versus time, the growth curves for E. faecalis , P. aeruginosa and their mixtures were obtained. The differences in shape of curves of single microorganisms and their mixtures were compared. Also, the thermokinetic parameters of single microorganisms and their mixtures (growth constant, generation time, detection time and amount of heat released) were calculated.