ISOLATED STRAIN FROM RESIDUAL SLUDGE WITH THE CAPACITY TO REMEDIATE THEM AND WITH BIOCONTROLLING AND PLANT GROWTH PROMOTION CHARACTERISTICS

ESCALANTE, J.; LENCINA, N; OTTADO, JORGELINA; GOTTIG, N.; GARAVAGLIA, B.S.

Congreso; SAMIGE 2022; 2022

bacterial isolate (OI43), obtained from vegetable oils acid residues, previously characterized by its exoenzyme production capacity, proved to be efficient in reducing the chemical oxygen demand of these residues. The evaluation of the toxicity of the treated residue was followed by the use of lettuce seedlings (Lactuca sativa L) and onion bulbs (Allium cepa). In both models, it was shown that the residue treatment with the bacterial isolate OI43 reduced its toxicity, allowing its final disposal in soils destined for that purpose. On the other hand, in order to evaluate the plant growth promoting activity of OI43, lettuce seedlings were inoculated with culture suspensions of 3x108 CFU/mL and biomass development was analyzed. The average of fresh and dry weight of the vegetative tissue was measured in these inoculated and control plants. As a result, both parameters showed a significant increase when OI43 was present. In parallel, isolate OI43 was analyzed as a biocontroller. Mushrooms used include Rhizoctonia solani, Fusarium verticillioides, Fusarium sp., Fusarium graminearum and Macrophomina phaseolina. Isolate OI43 showed significant biocontrol capacity for Macrophomina phaseolina. Finally, in order to identify the isolate OI43, 16sRNA and GyrA genes were amplified using specific oligonucleotides. Since, these sequences were not enough to identify the isolate, the OI43 genome was sequenced. The taxonomic classification was obtained by MiGA, a data management and processing system for microbial genomes and metagenomes. According to this tool, the dataset most likely belongs to the order Bacillales (p-value: 0.002) and probably belongs to the family Bacillaceae (p-value: 0.019).