Produção de quitinase por paenibacillus illinoisensis imobilizados em matriz de alginato

• Autor(a) principal: Silva, Francenya Kelley Lopes da
• 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/8516
• topic: Quitina; Imobilização celular; Biopolímeros; Gelificação iônica; Chitin; Cell immobilization; Biopolymers; Ionic gelation; CIENCIAS BIOLOGICAS::MICROBIOLOGIA

Chitins are enzymes that act in the hydrolysis of chitin, a polysaccharide present in insect exoskeletons, crustacean shells, algae and fungal cell walls. Such enzymes can be applied in the preparation of chitosan and chitoligomers for pharmaceutical use, in the control of pathogenic fungi and in the treatment of chitinous residues derived from fishing. Improvement in the production of chitinase and other enzymes by microorganisms can be achieved by the cell immobilization technique, which consists in fixing or confining cells in an inert carrier. The cell immobilization confers protection against the shear force, promotes the easy separation of the cells from the culture medium, as well as the product and decrease of the cost of production, since, it allows the reuse of the biocatalyst. Among the materials used as support in a cellular immobilization, biopolymers, such as alginate, have been highlighted as non-toxic, inexpensive and highly available in nature. The present work aims to immobilize Paenibacillus illinoisensis in a polymer matrix of alginate for chitinase production, evaluating the differences in the production of the enzyme between free and immobilized cells. Thus, an anionic alginate solution containing the cells was dripped into a cationic solution of CaCl2, leading to the instant formation of spheres having an average size of 4 mm. The immobilization efficiency was 99.99% ± 0.01. The biomass was determined during enzymatic production and the maximum values were 1.45 x 108 CFU / mL in 96 hours for immobilized cells and 8.95 x 107 CFU / mL in 48 hours for free cells, evidencing an increase of 62.01% in the amount of cells immobilized in comparation to the free cells. The cell leakage from the immobilization support during the process was evaluated and corresponded to 6.46% of the total cells at the end of the fermentation. The enzymatic activity was 0.902 U in 96 hours for the immobilized cells and 0.641 U in 48 hours for the free cells, demonstrating an activity increase of 40.71%. The immobilized cells were also tested for reuse in a sequential batch system and demonstrated stability in the production for 4 cycles of 96 hours each, losing 21.04% of the initial activity at the end of the fourth cycle. The cellular immobilization methodology resulted in spheres with capacity to maintain the cell viability during the bioprocess, increase of the enzymatic activity, low leakage of cells of the support and reuse capacity, being able to be used in the future for the production of chitinase for its various applications.