Poster (Painel)
| 2153-1 | Partitioning and purification of polygalacturonases produced by Aspergillus niger URM 5162 using PEG-phosphate in an aqueous two-phase system | | Autores: | Maciel, M.H.C. (UFPE - Micoteca URM, Federal University of Pernambuco) ; Ottoni, C.A. (UMINHO - Micoteca da Universidade do Minho) ; Herculano, P.N. (UFRPE - Federal Rural University of Pernambuco) ; Porto, T.S. (UFRPE - Federal Rural University of Pernambuco) ; Porto, A.L.F. (UFRPE - Federal Rural University of Pernambuco) ; Santos, C, (UMINHO - Micoteca da Universidade do Minho) ; Lima, N (UMINHO - Micoteca da Universidade do Minho) ; Moreira, K.A. (UFRPE - Federal Rural University of Pernambuco) ; Souza-Motta, C.M. (UFPE - Micoteca URM, Federal University of Pernambuco) |
Resumo Pectinases, or pectinolytic enzymes, are naturally produced by plants, filamentous fungi, bacteria and yeasts. The pectinases are of great importance to clarify and reduce viscosity in fruit juices, improving and increasing the filtration efficiency. When used in the crushing of grapes or wine must improve juice extraction, reduce the time to clarify and enhance the content of terpenes in wine. The filamentous fungi most frequently used for industrial purposes because as much as 90% of the enzyme can be excreted into the culture medium. The partitioning and purification of polygalacturonases (PG) produced by Aspergillus niger URM 5162 were investigated in aqueous two-phase systems (ATPS), formed by polyethylene glycol and phosphate salts (PEG⁄phosphate). To evaluate the effect of the 4 independent variables – molar mass of polyethylene glycol (PEG) (400-8000 g⁄mol MPEG), PEG concentration (12.5-17.5%, w/w - CPEG), phosphate concentration (15-25%, w⁄w, CPHOS) and pH (6.0, 8.0) – on the 3 response variables: partition coefficient (K), activity yield (Y) and purification factor (PF), a factorial design (24) was used. The endo-polygalacturonases (endo-PG) were preferentially partitioned in the top phase. For endo-PG, the highest values for the response variables K, Y and PF of 1.23, 74.04% and 8.18, respectively, were obtained for a CPEG of 12.5% (w⁄w), MPEG of 8000 g⁄mol, and CPHOS of 25% (w/w) at pH 6.0. Also, exo-polygalacturonases (exo-PG) were preferentially partitioned in the top phase. In this case, the highest values of K (2.40), Y (33.33%), and PF (1.98) were obtained with a MPEG of 8000 g⁄mol, CPEG of 12.5% (w⁄w), and CPHOS of 25% (w⁄w) at pH 6.0. In both cases, MPEG had a positive influence on K, Y and PF. The conditions of MPEG 8000 g⁄mol, CPEG of 12.5% (w⁄w), and CPHOS of 25% (w⁄w) at pH 6.0 were considered the most suitable for the purification of PG produced by A. niger URM 5162. Furthermore, MPEG and CPHOS were the most important independent variables. The PEG/phosphate system is a useful cost-effective alternative for PG purification. |