Produção e caracterização de exopolissacarídeos de bacillus

• Autor(a) principal: Paula, Bruna Marques de
• Data de Publicação: 2019
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Ceará (UFC)
• Texto Completo: http://www.repositorio.ufc.br/handle/riufc/50356
• topic: Exopolissacarídeos; Bacillus sp; Fermentação; Antioxidante

Biopolymers extracted via microbiological fermentation have a wide range of application in various fields of industry. The selection of microorganisms capable of synthesizing these compounds has been the subject of several researches and bacteria of the genus Bacillus sp have been studied and reported as promising for the production of these compounds. Thus, the present study aimed to produce and characterize bacillus exopolysaccharides aiming to identify promising strains. The production of the biopolymers was carried out by cultivating the bacteria Bacillus pumilus (RAB9), Bacillus cereus (CMIAT 186) and two strains of Bacillus stratosphericus (RMIAT 109 and CMIAT 61) in sucrose, yeast extract and mineral salts. Fermentations were performed for 72 hours under stirring (200 rpm) at 30 ° C. Isolation of the biopolymer occurred by precipitation of the supernatant obtained by fermentation with anhydrous ice-cold ethanol in a 3: 1 ratio. Purification of the product was conducted by successive washes and centrifugation of the material with said solvent. The functional groups present in the polysaccharide were elucidated from infrared spectroscopy. Thermogravimetric analysis (TGA) was performed to know its thermal properties, and a decomposition temperature around 160 ° C was verified. Antioxidant capacity analysis by DPPH showed low free radical uptake capacity (for 300 µg mL-1 EPS mL-1, 2.34% of the maximum obtained capacity observed for EPS produced by Bacillus stratosphericus CMIAT 186), but giving us perspective for further studies. The results of chemical, thermal and biological analyzes show that the different Bacillus sp strains studied in the present work produce exopolysaccharide with similar characteristics that have not been reported in the literature. Further studies on technological functionalities, the use of new purification methods and complementary characterizations are needed to evaluate their potential for use in the food, pharmaceutical or cosmetics industries.