Evaluation of the tolerance and biotransformation of ferulic acid by Klebsiella pneumoniae TD 4.7.

Abstract

Derived compounds from lignin have been used as substrates for chemical and biological processes for obtainment bioproducts. The ferulic acid is a lignocellulosic biomass whose biotransformation in flavors compounds was described. The objective of this study was the bioconversion of ferulic acid to 4-vinylguaiacol by Klebsiella pneumoniae TD 4.7. The biotransformation of commercial ferulic acid into 4-vinylguaiacol in a semi synthetic liquid medium containing the ferulic acid at an initial concentration of 300 mg L-1 reached 32.4%. The ferulic acid obtained from alkaline hydrolysis of the sugar cane bagasse at 300 mg L-1 allowed the yield of 1.3 mmol L-1 of 4-vinylguaiacol, corresponding to 81.7% of the ferulic acid content. The data indicated that the bacterial strain decarboxylated the ferulic acid to 4-vinylguaiacol and the presence of an active cell associated ferulic acid decarboxylase. The enzyme showed maximum activity at pH 5.5 and 40 °C and was stable at pH range 4.5 to 9.0 and temperature up 20 to 45 °C. According to these biochemical properties and performance to bioconversion of ferulic acid to 4-vinylguaiacol, this enzyme could be viable for application in food industry.