The present study has been conducted towards isolation of bacteria capable of producing heliotropin via microbial conversion. Strain ZMT-1 capable of synthesizing heliotropin efficiently was obtained by enrichment culture of soil samples and a high-throughput screening method, and identified as Serratia liquefaciens. Heliotropin was identified by gas chromatography and gas chromatography-mass spectrometry analysis. In addition, the culture medium was optimized to improve heliotropin yield by experimental designs. The application of a Plackett-Burman design found that NH4NO3 and K2HPO4•3H2O have significant effects on heliotropin production. Central composite design experiments were further used to predict the optimal concentrations of NH4NO3 and K2HPO4•3H2O, which were 1.0 and 0.5 g/l, respectively. After the optimization of cultural medium, heliotropin yield was increased by 4.52-fold when compared with the unoptimized minimal medium. This study is the first to report the biosynthesis of heliotropin by S. liquefaciens. S. liquefaciens ZMT-1 can produce heliotropin efficiently, indicating its potential as one heliotropin-producing strain.
Keywords: Central composite design; Enrichment culture; Heliotropin; High-throughput screening; Microbial conversion; Plackett–Burman design; Serratia liquefaciens.