Banca de DEFESA: NAIRANE DA SILVA ROSA LEÃO

DEVELOPMENT OF BIOPROCESSES FOR BIOINSECTICIDE PRODUCTION FROM MICRO-ORGANISMS ISOLATED FROM

SOIL IN PERNAMBUCO, BRAZIL.

biocontrol; sustainable bioreactor; filamentous fungi; solid state fermentation; aqueous two-phase system.

The biotechnology industry focused on the production of enzymes used in several industrial areas has provided numerous methodological tools in its bioprocesses, especially in the use of filamentous fungi in the production of bioactive compounds. Among these compounds, protease stands out, the enzyme responsible for the hydrolysis of the peptide bonds of other proteins, which may be a potential cofactor in the activity against insects. However, one of the obstacles for the biotechnology industry is the increase in scale in the production and purification process of bioactives. Therefore, the objective of this thesis was to develop a sustainable biodegradable reactor from the Crescentia Cujete fruit to extract the protease by aqueous two-phase system (SDFA) and finally to verify the biological activity. Eight fungal strains isolated from the Caatinga were used for this study in solid state fermentation using wheat bran as a substrate in 72 hours at 30°C, after selection, fermentation was carried out in the Crescentia Cujete fruit for 120 hours at 30°C. SDFA composed of polyethylene glycol and phosphate salts was used for extraction under different conditions determined by a 24 factorial design. The Aspergillus flavus UCP 0316 strain was selected as the best protease producer with 139.13 U/mL in 72 hours of fermentation. The use of the Crescentia Cujete fruit as a biological reactor at a temperature of 25ºC with a humidity of 20 and 40% had a production of 34.86 U/mL and 30.4 U/mL respectively, proving its potential as a new bioreactor. In SDFA extraction, the assay selected for containing more favorable conditions was composed of MPEG (8000g/mol), CPEG (2.5%), C phosphate (15%) at pH 6.0, in all assays the protease partitioned to the salt-rich phase. According to the electrophoresis performed, the molecular weight of 65 kDa and 150 kDa is suggested. Evidences indicated growth inhibition of Spodoptera frugiperda during its initial phase of development. Finally, the proteases obtained from the fungal strain Aspergillus flavus UCP0316, has potential for application in the biotechnological field, offering the industrial segment of Pernambuco an alternative source for the commercial market.