A rapid colorimetric screening method for vanillic acid and vanillin-producing bacterial strains

Area of Science:

• Microbiology
• Biotechnology
• Biochemistry

Background:

• Ferulic acid, a lignin component, is a precursor for valuable compounds like vanillin and vanillic acid.
• Efficient microbial biotransformation methods are crucial for sustainable production of these compounds.
• Current methods for isolating such microbes can be time-consuming.

Purpose of the Study:

• To develop and apply a rapid colorimetric screening method for isolating bacterial strains that biotransform ferulic acid.
• To identify a bacterial strain capable of producing vanillin and vanillic acid from ferulic acid.
• To assess the strain's ability to utilize partially digested lignin for biovanillin and vanillic acid production.

Main Methods:

• A colorimetric screening method based on pH changes from ferulic acid degradation was employed.
• Pseudomonas sp. AZ10 UPM was isolated and its biotransformation capabilities were evaluated.
• The strain's production of vanillic acid and biovanillin from ferulic acid and partially digested lignin was quantified.

Main Results:

• Pseudomonas sp. AZ10 UPM showed rapid color changes indicative of ferulic acid degradation.
• The strain achieved a vanillic acid yield (Yp/s) of 1.08 mg/mg and productivity (Pr) of 53.1 mg/L/h.
• Using partially digested lignin, the strain produced 30.7 mg/L vanillic acid and 1.94 mg/L biovanillin.

Conclusions:

• A rapid colorimetric screening method effectively isolated a biovanillin producer from ferulic acid.
• Pseudomonas sp. AZ10 UPM can produce vanillic acid and biovanillin from ferulic acid and enzymatically pre-treated lignin.
• This study presents the first report of using a rapid colorimetric method for isolating bacterial vanillin and vanillic acid producers.