A novel Aspergillus oryzae esterase that hydrolyzes 4-hydroxybenzoic acid esters

Area of Science:

• Biochemistry
• Enzymology
• Microbiology

Background:

• Aspergillus oryzae is a fungus with industrial applications.
• Feruloyl esterases and tannases are enzymes found in Aspergillus.
• Hypothetical proteins require biochemical characterization to understand their function.

Purpose of the Study:

• To biochemically characterize a hypothetical protein from Aspergillus oryzae.
• To determine the hydrolytic activity and substrate specificity of the enzyme.
• To investigate the enzyme's effect on the antimicrobial activity of parabens.

Main Methods:

• Recombinant protein purification.
• Enzyme activity assays using various ester substrates.
• Testing the enzyme's effect on paraben antimicrobial activity against Aspergillus oryzae.

Main Results:

• The purified protein exhibited hydrolytic activity against ethyl, propyl, and butyl esters of 4-hydroxybenzoic acid.
• The enzyme did not display feruloyl esterase or tannase activity.
• The enzyme hydrolyzed butyl 4-hydroxybenzoic acid, reducing its antimicrobial efficacy against Aspergillus oryzae.

Conclusions:

• The characterized hypothetical protein functions as an esterase, distinct from feruloyl esterase and tannase.
• This enzyme can degrade parabens, potentially impacting their antimicrobial applications.
• Understanding this enzyme's activity provides insights into Aspergillus metabolism and potential biotechnological uses.