Direct biodegradation of eugenol to coniferyl aldehyde and other higher value-added products by Gibberella fujikuroi ZH-34

ABSTRACT

BACKGROUND: Eugenol is an economically favorable substrate for the microbial biotransformation of aromatic compounds. Coniferyl aldehyde is one kind of aromatic compound that is widely used in condiment and medical industries; it is also an important raw material for producing other valuable products such as vanillin and protocatechuic acid. However, in most eugenol biotransformation processes, only a trace amount of coniferyl aldehyde is detected, thus making these processes economically unattractive. As a result, an investigation of new strains with the capability of producing more coniferyl aldehyde from eugenol is required. RESULTS: We screened a novel strain of Gibberella fujikuroi, labeled as ZH-34, which was capable of transforming eugenol to coniferyl aldehyde. The metabolic pathway was analyzed by high-performance liquid chromatography­mass spectrometry and transformation kinetics. The culture medium and biotransformation conditions were optimized. At a 6 h time interval of eugenol fed-batch strategy, 3.76 ± 0.22 g/L coniferyl aldehyde was obtained, with the corresponding yield of 57.3%. CONCLUSIONS: This work improves the yield of coniferyl aldehyde with a biotechnological approach. Moreover, the fed-batch strategy offers possibility for controlling the target product and accumulating different metabolites