Bioprospecção de bactérias quitinolíticas e caracterização da atividade da enzima quitinase

• Autor(a) principal: Alexandre, Artur Ribeiro de Sá
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/8471
• topic: Bioprospecção; Quitina; Quitinase; Bacteriologia ambiental; Bioprospecting; Chitin; Chitinase; Environmental bacteriology; CIENCIAS BIOLOGICAS::MICROBIOLOGIA

Bioprospecting is defined as the search for organisms, genes, enzymes, compounds, processes and any pieces from living beings, that could have economic potential, and eventually lead to a product development. Thus, enzymes, protein catalysts, have aroused the interest of industries for its conversion mode specific biomass, low energy cost and not production of toxic waste. Chitinases are enzymes that catalyze the lysis of chitin (biopolymer composed of N-acetylglucosamine monomers), and thus have several applications, among them: obtaining N-acetylglucosamine monomers, used in the production of prebiotics; degradation of chitinous waste from fishing activities; and the use in control of fungi and insects. The present work aimed to bioprospect chitinase producing bacteria from soil samples and to characterize the enzymatic activity patterns of the best bacterial isolate. To do so, a screening with 17 soil samples collected in the states of Minas Gerais, Santa Catarina and Rio Grande do Sul, was carried out using a culture medium with colloidal chitin. Thirteen chitinase producing bacteria were obtained, among them, the isolate Q1 (identified as Paenibacillus illinoisensis), demonstrated to be a good producer of the enzyme and thus was selected for determination and optimization of its chitinase activity evaluating reaction time, temperature and pH. The chitinase produced by the isolate showed 0.098 U of activity, which was subsequently improved to 0.66 U when tested under the optimal conditions of 1 hour of reaction at 37 ºC and pH 4, an increase of 573% over the initial value. The values of chitinase activity from the isolate P. illinoisensis are close to those found in other studies, which also emphasize the potential application of the enzyme, mainly in the control of phytopathogenic pests. Bioprospecting of chitinase producing bacteria is possible and promising.