Continuous xylanase production with Aspergillus nidulans under pyridoxine limitation using a trickle bed reactor

Michael Müller; Rolf A Prade; Fernando Segato; Hasan K Atiyeh; Mark R Wilkins

doi:10.1016/j.biortech.2015.01.085

Continuous xylanase production with Aspergillus nidulans under pyridoxine limitation using a trickle bed reactor

Bioresour Technol. 2015:188:219-25. doi: 10.1016/j.biortech.2015.01.085. Epub 2015 Feb 2.

Authors

Michael Müller¹, Rolf A Prade², Fernando Segato³, Hasan K Atiyeh⁴, Mark R Wilkins⁵

Affiliations

¹ Department of Biosystems Engineering, Oklahoma State University, 111 Agriculture Hall, Stillwater, OK 74078, USA. Electronic address: michael.mueller@pfi-biotechnology.de.
² Department of Microbiology and Molecular Genetics, Oklahoma State University, 307 Life Sciences East, Stillwater, OK 74078, USA. Electronic address: rolf.prade@okstate.edu.
³ Department of Microbiology and Molecular Genetics, Oklahoma State University, 307 Life Sciences East, Stillwater, OK 74078, USA.
⁴ Department of Biosystems Engineering, Oklahoma State University, 111 Agriculture Hall, Stillwater, OK 74078, USA. Electronic address: hasan.atiyeh@okstate.edu.
⁵ Department of Biosystems Engineering, Oklahoma State University, 111 Agriculture Hall, Stillwater, OK 74078, USA. Electronic address: mark.wilkins@okstate.edu.

PMID: 25683507
DOI: 10.1016/j.biortech.2015.01.085

Abstract

A trickle bed reactor (TBR) with recycle was designed and tested using Aspergillus nidulans with a pyridoxine marker and over-expressing/secreting recombinant client xylanase B (XynB). The pyridoxine marker prevented the fungus from synthesizing its own pyridoxine and fungus was unable to grow when no pyridoxine was present in the medium; however, enzyme production was unaffected. Uncontrolled mycelia growth that led to clogging of the TBR was observed when fungus without a pyridoxine marker was used for XynB production. Using the fungus with pyridoxine marker, the TBR was operated continuously for 18 days and achieved a XynB output of 41 U/ml with an influent and effluent flow rate of 0.5 ml/min and a recycle flow rate of 56 ml/min. Production yields in the TBR were 1.4 times greater than a static tray culture and between 1.1 and 67 times greater than yields for SSF enzyme production stated in the literature.

Keywords: Biomass; Bioreactors; Enzymes; Filamentous fungi.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Aspergillus nidulans / enzymology*
Biomass
Bioreactors*
Culture Media / chemistry
Endo-1,4-beta Xylanases / biosynthesis*
Equipment Design
Fermentation
Genotype
Hydrogen-Ion Concentration
Industrial Microbiology / methods
Pyridoxine / chemistry*

Substances

Culture Media
Endo-1,4-beta Xylanases
Pyridoxine