title: Evaluation of cell recycle on Thermomyces lanuginosus Xylanase A production by Pichia pastoris GS 115.
abstract: This work aims to evaluate cell recycle of a recombinant strain of Pichia pastoris GS115 on the Xylanase A (XynA) production of Thermomyces lanuginosus IOC-4145 in submerged fermentation. Fed-batch processes were carried out with methanol feeding at each 12 h and recycling cell at 24, 48, and 72 h. Additionally, the influence of the initial cell concentration was investigated. XynA production was not decreased with the recycling time, during four cell recycles, using an initial cell concentration of 2.5 g/L. The maximum activity was 14,050 U/L obtained in 24 h of expression. However, when the initial cell concentration of 0.25 g/L was investigated, the enzymatic activity was reduced by 30 and 75% after the third and fourth cycles, respectively. Finally, it could be concluded that the initial cell concentration influenced the process performance and the interval of cell recycle affected enzymatic production.
authors.affiliation: Escola de Química-Universidade Federal do Rio de Janeiro, Caixa Postal 68542, CEP 21945-970, Rio de Janeiro, RJ, Brazil.
authors.forename: Verônica
authors.initials: V
authors.lastname: Ferreira
authors.forename: Patricia C
authors.initials: PC
authors.lastname: Nolasco
authors.forename: Aline M
authors.initials: AM
authors.lastname: Castro
authors.forename: Juliana N C
authors.initials: JN
authors.lastname: Silva
authors.forename: Alexandre S
authors.initials: AS
authors.lastname: Santos
authors.forename: Mônica C T
authors.initials: MC
authors.lastname: Damaso
authors.forename: Nei
authors.initials: N
authors.lastname: Pereira Júnior
mesh_terms: D001203:Ascomycota / Q000201:enzymology* / Q000235:genetics; D019149:Bioreactors / Q000382:microbiology*; D018929:Cell Culture Techniques / Q000379:methods*; D049109:Cell Proliferation; D002470:Cell Survival; D043364:Endo-1,4-beta Xylanases / Q000096:biosynthesis* / Q000235:genetics; D010843:Pichia / Q000502:physiology*; D015202:Protein Engineering / Q000379:methods*
chemical_list: D043364:Endo-1,4-beta Xylanases