High-yield production of aryl alcohol oxidase under limited growth conditions in small-scale systems using a mutant Aspergillus nidulans strain

• Published in: Journal of industrial microbiology & biotechnology Vol. 44; no. 2; pp. 247 - 257
• Main Authors: Pardo-Planas, Oscar, Prade, Rolf A., Wilkins, Mark R.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.02.2017; Oxford University Press
• Subjects: Agricultural production; Alcohol; Alcohol Oxidoreductases - biosynthesis; Aspergillus nidulans; Aspergillus nidulans - enzymology; Aspergillus nidulans - genetics; Biochemistry; Bioinformatics; Biomass; Biomedical and Life Sciences; Biotechnology; Carbon; Cell Culture and Bioengineering - Original Paper; Cell growth; Consortia; Culture Media - chemistry; Energy; Enzymes; Fermentation; Fungi; Genetic Engineering; Growth conditions; Hydrogen-Ion Concentration; Industrial Microbiology; Inorganic Chemistry; Life Sciences; Lignin; Microbiology; Nutrients; Proteins; Pyridoxine - metabolism; Aryl alcohol oxidase; Filamentous fungi; Pyridoxine limitation; Enzyme production; MtGloA
• ISSN: 1367-5435; 1476-5535
• DOI: 10.1007/s10295-016-1884-x

Aryl alcohol oxidase (MtGloA) is an enzyme that belongs to the ligninolytic consortium and can play an important role in the bioenergy industry. This study investigated production of an MtGloA client enzyme by a mutant strain of Aspergillus nidulans unable to synthesize its own pyridoxine. Pyridoxine limitation can be used to control cell growth, diverting substrate to protein production. In agitated culture, enzyme production was similar when using media with 1 mg/L and without pyridoxine (26.64 ± 6.14 U/mg mycelia and 26.14 ± 8.39 U/mg mycelia using media with and without pyridoxine, respectively). However, the treatment lacking pyridoxine had to be supplemented with pyridoxine after 156 h of fermentation to sustain continued enzyme production. Use of extremely diluted pyridoxine levels allowed reduced fungal growth while maintaining steady enzyme production. Concentrations of 9 and 13.5 µg/L pyridoxine allowed MtGloA production with a growth rate of only 5% of that observed when using the standard 1 mg/L pyridoxine media.