Isolation and identification of microorganisms with agro-industrial interest from soil samples from primary forests in Colta city

Abstract

Introduction: Primary forests maintain virgin areas in which there is much unknown biological diversity. Objective: The purpose of this study is to isolate unknown species of lactic acid bacteria (LAB), fermentative yeasts, and aerobic fermentative bacteria from primary forest soils, to verify their potential use in agroindustry. Methodology. In the case of lactic acid bacteria, soil samples from the primary forest of Cañi were planted in an acid medium with MRS and anaerobiosis with 13.3 x10^5 CFU/mL present at 35°C, the isolated species degraded the lactose and acidified the substrate. Yeasts were sown from soil samples using 12 x10^5 CFU/mL present, in a neutral YPD medium with the presence of dextrose in the presence of oxygen and a bacterial growth inhibitor at 30°C, then the species were selected. resistant to 8% alcohol, glucose and fructose fermented well except lactose and fermentation was conducted in citrus juice for 45 days, eliminating pathogens and ethanol and CO2 production was obtained. Fermentative bacteria were planted from of primary forest soil samples with 12 x10^5 CFU/mL present, on GYC agar under aerobic conditions at 30°C. Results. The microorganisms, especially lactic acid bacteria, of which only two isolated species fermented lactose very easily, C3R2 and the sample C3R1, which metabolized lactose very quickly in yeasts, were characterized. Sample 001 BC1 was the one that could generate the greatest gas production and passed the SH2 test, which is not harmful for its use to degrade biomass. In fermentative bacteria, samples 009C2 and 007C1' were the ones that survived alcohol and those that they fermented in a better way and in the SH2 test negative results were presented, with which it can also be inferred that it does not affect human use, finally the yeasts isolated after 45 days metabolizing the citrus juice with the release of ethanol being a fermentation of agro-industrial interest. Conclusion. With this work, lactic acid bacteria isolated from the soil of primary forests with fermentative capacities against lactose are obtained, in addition to their application to degrade biomass. Finally, the isolated yeasts metabolize the citrus juice with the release of ethanol, being a fermentation of agro-industrial interest