Microorganismos de uso agroindustrial aislados del suelo de un bosque primario de la parroquia Pungalá cantón Riobamba.

Abstract

The objective of this study was to isolate, purify and identify bacteria and yeasts for agroindustrial use from a primary forest soil of the Pungala Town in the Riobamba City and to analyze their physical-chemical properties by identifying the microorganisms through biochemical tests and the physical-chemical analysis of the soil through bromatological tests. The type of sampling that was carried out was at random with the help of an auger, to then make a stock solution and then start with the dilutions. Finally, the sowing of the microorganisms in MRS agar, Acetobacter glucose and Saborau was performed. It was incubated for 48 hours at 37, 27 and 30ºC. Afterwards, the isolation was carried out and the identification of each microorganism was made according to its morphology, color, surface and Gram staining. The biochemical tests such as catalase, oxidase for lactic and acetic acid bacteria, and potassium hydroxide only for LAB were performed; characterization tests such as carbohydrate fermentation and YPD broth in yeasts. It was obtained 5 species of lactic acid bacteria, 2 species of acetic acid bacteria and yeasts. All lactic acid bacteria were positive for staining and negative for oxidase, catalase and KOH. As for LAB all negative for staining and oxidase, but positive for catalase, as for the fermentation of substrates helped to the possible identification of each species and for the physical-chemical analysis was performed following the standards established for each mineral. It was concluded that the soil of the present study is rich in minerals and that the isolated species may belong to the genus Lactobacillus, Lactococcus, Bifidobacterium, Acetobacter and Saccharomyces. It is recommended to use other biochemical tests such as API 50 CHL, or in a real time PCR for a better identification of each of the isolated microorganisms.