Degradation of phenolic compounds by the lignocellulose deconstructing thermoacidophilic bacterium Alicyclobacillus Acidocaldarius

• DOI: 10.1007/s10295-015-1700-z
• Publication Date: 2015-11-05T07:17:40Z
• Authors: John E Aston; William A Apel; Brady D Lee; David N Thompson; Jeffrey A Lacey; Deborah T Newby; David W Reed; Vicki S Thompson
• Keywords: Coumaric acid; Guaiacol

Abstract Alicyclobacillus acidocaldarius, a thermoacidophilic bacterium, has a repertoire of thermo- and acid-stable enzymes that deconstruct lignocellulosic compounds. The work presented here describes the ability of A. acidocaldarius to reduce the concentration of the phenolic compounds: phenol, ferulic acid, ρ-coumaric acid and sinapinic acid during growth conditions. The extent and rate of the removal of these compounds were significantly increased by the presence of micro-molar copper concentrations, suggesting activity by copper oxidases that have been identified in the genome of A. acidocaldarius. Substrate removal kinetics was first order for phenol, ferulic acid, ρ-coumaric acid and sinapinic acid in the presence of 50 μM copper sulfate. In addition, laccase enzyme assays of cellular protein fractions suggested significant activity on a lignin analog between the temperatures of 45 and 90 °C. This work shows the potential for A. acidocaldarius to degrade phenolic compounds, demonstrating potential relevance to biofuel production and other industrial processes.