Purification of recombinant peroxidase from Thermobifida fusca IP1 for β-carotene degradation into industrial flavouring agents

Carotenoids are important colored components of food with several essential health benefits. Because of their characteristic fruity aroma, the cleavage products of carotenoids are being used as flavouring agents in the food industry. Enzymes are needed to get cleavage products of carotenoids in order to avoid the very laborious and costly extraction processes of particular aroma compounds, such as α- and β-ionone, directly from their plant sources. So, for an easy and cost effective access to flavouring agents, the role of enzymes is undeniably crucial. The present work was therefore undertaken to isolate an industrially important recombinant peroxidase enzyme to obtain the flavouring agents. Thermobifida fusca (accession number KM677184), isolated from manure piles, was found to effectively degrade β-carotene. The gene encoding T. fusca extracellular heme-containing peroxidase (TfuDyP) was amplified from genomic DNA of T. fusca and was cloned in vector pET24b. TfuDyP was expressed heterologously in E. coli (BL21) and a recombinant enzyme was used for the transformation of β-carotene into volatile products which were identified by the GC-MS (Gas Chromatography-Mass Spectrophotometry). The enzyme was found effective as various volatile degradation products of β-carotene, such as β-ionone, β-cyclocitral, β-ionone-5,6-epoxide and dihydroactinidiolide were identified. With these results, we are inclined to conclude that the extracellular peroxidase enzyme obtained from T. fusca IP1 has the potential to be used in the food industry. In spite of the various reports on the subject, the use of this particular bacterial strain in the enzyme production is being reported for the first time in the present work.