title: Comparison of stirred tank and airlift bioreactors in the production of polygalacturonases by Aspergillus oryzae.
abstract: The production of endo and exo-polygalacturonase (PG) by Aspergillus oryzae IPT 301 was studied in a stirred tank bioreactor (STR) and an internal circulation airlift bioreactor. Using a factorial experimental design, a soluble culture medium was defined which allowed the production of exo- and endo-PG comparable to that obtained in a medium containing suspended wheat bran. The soluble medium was used in tests to compare the production of these enzymes in the STR and airlift bioreactor. In these tests, after 96 h, maximum enzymatic activity values achieved for exo- and endo-PG were 65.2 units (U) per mL and 91.3 U mL(-1), in the STR, with similar activity values of 60.6 U mL(-1) and 86.2 U mL(-1), respectively, being achieved in the airlift bioreactor. The airlift bioreactor also showed satisfactory results regarding the oxygen transfer rate in this process, indicating its potential to be used in an eventual larger scale production of exo- and endo-PG, with lower costs for both installation and operation.
authors.affiliation: Instituto de Biotecnologia, Universidade de Caxias do Sul, Caxias do Sul, RS, Brazil.
authors.forename: Roselei Claudete
authors.initials: RC
authors.lastname: Fontana
authors.forename: Tomás Augusto
authors.initials: TA
authors.lastname: Polidoro
authors.forename: Mauricio Moura
authors.initials: MM
authors.lastname: da Silveira
mesh_terms: D001236:Aspergillus oryzae / Q000201:enzymology*; D019149:Bioreactors / Q000382:microbiology*; D003470:Culture Media; D010100:Oxygen; D010936:Plant Extracts / Q000378:metabolism; D011096:Polygalacturonase / Q000096:biosynthesis*; D013997:Time Factors; D014908:Triticum / Q000378:metabolism
chemical_list: D003470:Culture Media; D010936:Plant Extracts; D011096:Polygalacturonase; D010100:Oxygen