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Production of Polygalacturonases by Aspergillus section Nigri Strains in a Fixed Bed Reactor
Mycology Department, Federal University of Pernambuco, Cidade Universitária, Recife 50670-420, Pernambuco, Brazil
IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Micoteca da Universidade do Minho, University of Minho, Campus of Gualtar, Braga 4710-057, Portugal
Academic Unit of Garanhuns, Federal Rural University of Pernambuco, Garanhuns 55292-270, Pernambuco, Brazil
* Author to whom correspondence should be addressed.
Received: 26 November 2012; in revised form: 9 January 2013 / Accepted: 11 January 2013 / Published: 28 January 2013
Abstract: Polygalacturonases (PG) are pectinolytic enzymes that have technological, functional and biological applications in food processing, fruit ripening and plant-fungus interactions, respectively. In the present, a microtitre plate methodology was used for rapid screening of 61 isolates of fungi from Aspergillus section Nigri to assess production of endo- and exo-PG. Studies of scale-up were carried out in a fixed bed reactor operated under different parameters using the best producer strain immobilised in orange peels. Four experiments were conducted under the following conditions: the immobilised cells without aeration; immobilised cells with aeration; immobilised cells with aeration and added pectin; and free cells with aeration. The fermentation was performed for 168 h with removal of sample every 24 h. Aspergillus niger strain URM 5162 showed the highest PG production. The results obtained indicated that the maximum endo- and exo-PG activities (1.18 U·mL−1 and 4.11 U·mL−1, respectively) were obtained when the reactor was operating without aeration. The microtitre plate method is a simple way to screen fungal isolates for PG activity detection. The fixed bed reactor with orange peel support and using A. niger URM 5162 is a promising process for PG production at the industrial level.
Keywords: Aspergillus niger; orange peel; immobilization cells; polygalacturonases; fixed bed reactor
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MDPI and ACS Style
Maciel, M.; Ottoni, C.; Santos, C.; Lima, N.; Moreira, K.; Souza-Motta, C. Production of Polygalacturonases by Aspergillus section Nigri Strains in a Fixed Bed Reactor. Molecules 2013, 18, 1660-1671.
Maciel M, Ottoni C, Santos C, Lima N, Moreira K, Souza-Motta C. Production of Polygalacturonases by Aspergillus section Nigri Strains in a Fixed Bed Reactor. Molecules. 2013; 18(2):1660-1671.
Maciel, Marília; Ottoni, Cristiane; Santos, Cledir; Lima, Nelson; Moreira, Keila; Souza-Motta, Cristina. 2013. "Production of Polygalacturonases by Aspergillus section Nigri Strains in a Fixed Bed Reactor." Molecules 18, no. 2: 1660-1671.