Microbial Biotransformation of Geranyl Acetate Using Pseudomonas fluorescens Strain MTCC2421 and Investigations of the Underlying Pathways
摘要
A microbial system or the enzymatic conversion of geranyl acetate into geraniol and lavandulol based on Pseudomonas fluorescens strain MTCC2421 was developed. The GC-MS analysis showed that the highest conversion of geranyl acetate was achieved at P. fluorescens inoculum of 150 µL, CFU 1.7 × 103 CFU/mL, 48 mg/L geranyl acetate, 37°C, pH 7, agitation speed of 150 rpm, and an incubation time of 7 days. Under these conditions, the major products of geranyl acetate conversion were geraniol (~67%) and β-nerol (~19%), while lavandulol (55–59%) and nerol (21%) were the major products at pH 5 and 9, respectively. The rates of biotransformation and formation of the products were significantly influenced by such factors as substrate, and inoculum concentrations, pH, and temperature. Analysis of the biotransformation product profiles revealed the possible pathways involved in the bioconversion of geranyl acetate, suggesting the involvement of an esterase in the formation of geraniol while lavandulol production proceeded via limonene formation. Geraniol isomerase and geraniol-acetyl transferase also played crucial roles in the biotransformation of geranyl acetate. Hence, the study highlighted the potential of P. fluorescens MTCC2421 in the production of geraniol and lavandulol, which may have significant industrial applications.