Banca de QUALIFICAÇÃO: SINARA CYBELLE TURIBIO E SILVA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : SINARA CYBELLE TURIBIO E SILVA
DATE: 17/08/2020
TIME: 09:00
LOCAL: Online
TITLE:

A DEFINIR

KEY WORDS:

Atrazine, biodegradation, Bacillus megaterium, Penicillium chrysogenum, biosorption, immobilization, biosorption, bioremediation, microcosm.

PAGES: 116
BIG AREA: Engenharias
AREA: Engenharia Química
SUMMARY:

Knowing the risks that atrazine can bring to the environment and human health, of its occurrence in soils and waters of human consumption and the potential of biodegradation techniques by microorganisms for decontamination, the present study aims to evaluate the process of removal of atrazine by a bacterial strain of Bacillus megaterium CCT 7935, isolated from an area with a history of atrazine application and by the fungal lineage Penicillium chrysogenum NRRL 807. The strain B. megaterium CCT 7935 was able to degrade this pesticide in bench-scale satisfactorily, mainly at high concentrations. The use of methanol, used as atrazine solvent, did not interfere in its degradation potential, despite presenting toxicity to the growth of the strain in selective medium; autoclaving decreased the bioavailability of soluble atrazine at high concentrations; and the presence of salts in the minimum mineral media influenced the detection of atrazine in HPLC, at which time there was a large difference in proportion between the amount of salts and the concentration of atrazine. Penicillium chrysogenum NRRL 807, in turn, also managed to demonstrate great potential for the removal of atrazine at lower concentrations, on a bench scale. Free spores were able to remove 40% of the atrazine present in the medium after 5 days; immobilized P. chrysogenum NRRL 807, in turn, removed 48%. Notably, atrazine was used as a carbon source, and the removal processes were probably led by the citrus enzymatic CYP450 and biosorption. After proving the capacity of B. megaterium CCT 7935 and P. chrysogenum NRRL 807 to degrade atrazine, both were also efficient in atrazine bioremediation in soil microcosms. However, although P. chrysogenum NRRL 807 had a small advantage in removal efficiency, it was able to inhibit other microorganisms. The perspective is that future studies evaluate the performance and process of these microorganisms in the degradation of atrazine in agricultural soils in order to clarify the influence of other natural variables on this specific type of soil, such as the presence of microorganisms selected by atrazine exposure and greater abundance of resources. 

BANKING MEMBERS:
Externo ao Programa - 1346198 - EVERALDO SILVINO DOS SANTOS
Externo à Instituição - CARLOS EDUARDO DE ARAÚJO PADILHA - UFRN
Externo à Instituição - FRANCISCO CANINDE DE SOUSA JUNIOR - UFRN