Aislamiento e identificación de bacterias termófilas de la fuente geotermal Aluchán ubicada en la provincia de Cotopaxi

Abstract

The aim of the current research was to isolate and identify the thermophilic bacteria found in Aluchán hot spring, located 3531 meters above the sea level in Cotopaxi province, Ecuador. A total volume of 2050 mL from the water sample was reserved, both for the physical-chemical analysis and for the bacterial isolation. Two samplings were carried out at different times of the year, the first sampling was carried out on October 12, 2021 and the second one on January 21,2022. Some in-situ samples were taken for the temperature and pH parameters, while for conductivity, pH, calcium, magnesium, phosphates, nitrates, iron, arsenic and coper, ex-situ analysis was carried out. Once in the laboratory, the samples were inoculated into an agar LB (Luria Bertani) culture medium through a surface seeding technique and incubated at 37 degrees Celsius during 24 to 48h, where a total of fifteen bacterial strains were isolated. The isolated strains were characterized according to their macro and microscopic morphology; in addition, catalase, urease and citrate biochemical tests were also carried out. Four strains were used for the molecular identification reflecting differences on the characteristics mentioned before. For the molecular analysis, NCBI (National Center for Biotechnology Information) data base was used. The physical-chemical analysis results revealed that water is classified as hard water, neutral pH or slightly acidic and high conductivity; thus, it is classified as hyperthermal. Of the total number of bacteria isolated, 100% were Gram-positive. With the use of molecular techniques, it was possible to identify the following bacteria: Bacilus Subtilis, Vogesella sp., Staphylococcus epidermidis. The microorganisms identified are connected with microbial biodiversity from other hot springs in Ecuador and the world, excluding Vogesella sp., since there is no documentation related in our country. Further research on bacterial microbiota present in Aluchán hot spring is recommended.