Efecto de tres crioprotectores en bacterias acido lácticas obtenidas del suelo de Rio Negro, Baños.

Abstract

This experimental work was carried out with the objective of evaluating the effect of three cryoprotectants (glycerol, dimethyl sulfoxide and ethylene glycol) on lactic acid bacteria obtained from the primary forest of Rio Negro, with regard to viability at days 0, 7, 15 and 30 days and their growth dynamics. A total of 1.5 ml of soil samples were used for each repetition, which consisted of 5 repetitions, with a total of 22.5 ml. A DCA experimental design with a single factor was applied. The experimental results obtained were subjected to analysis of variance, separation of means (Tukey's test with a P value ≤ 0.05) and descriptive statistics. According to our results the macroscopic characteristics of BAL colonies present a round punctiform shape, a creamy white color and an entire appearance and a size of 1.2 mm. Regarding the viability of the LAB, the best was the cryoprotectant glycerol since it presented at 0 days 0.00 CFU/mL; at 7 days 71.20 CFU/mL, at 15 days 154.40 CFU/mL and finally at 30 days 174.20 CFU/mL. With regard to the growth dynamics of lactic acid bacteria, the use of glycerol resulted in a better growth of LAB, with 9.8 CFU/mL at 24 hours, 19.0 CFU/mL at 72 hours and 35.4 CFU/mL at 96 hours. Therefore, it is recommended to use glycerol as a cryoprotectant for the development and growth of lactic acid bacteria.