Natural Vanillin Production from Isoeugenol by Using Pseudomonas putida in Biphasic Bioconversion Medium

Murat YILMAZTEKİN,Hüseyin KARAKAYA

doi:10.15832/ankutbd.866426

Abstract

Vanillin, which is principal aroma constituent of the beans obtained from vanilla orchids, is one of the most demanded flavoring agents in the world. Because of insufficient supply of natural vanillin, market demand is usually supplied by synthetic ones. Taking into consideration of consumer trends, interest to natural products are rising day by day instead of the synthetic counterparts. In this study, it was investigated possibility of usage biphasic system in bioconversion process of isoeugenol to vanillin by Pseudomonas putida (HUT 8100) culture. Organic phase was composed of isoeugenol as sole carbon source in medium while biocatalyst, P. putida culture, was dispersed in inorganic phase. Incubation was performed at 28 ○C, at pH 6.3 and 180 rpm shaking. Isoeugenol and vanillin amounts in medium were simultaneously analyzed in HPLC system at 270 nm. Isoeugenol has low solubility in water and it was tested in concentrations ranged between 5-60% (w/w) to compose biphasic system. In various initial substrate concentrations, vanillin reached the highest level in the medium containing 40% (w/w) isoeugenol after 120 h. In specified conditions, isoeugenol consumption and vanillin production were investigated by following the bioconversion medium periodically for 17 days. According to the obtained results, it was determined that 11.95 g L-1 vanillin was produced with 6.2% molar yield at the end of 15 days bioconversion. It is thought that, obtained result by using biphasic system is very important for the industrial applications in production of natural vanillin via bioconversion.

Highlights

Vanillin (4-hydroxy-3-methoxybenzaldehyde) which naturally occurs in vanilla orchid pods, is one of the most important flavoring compounds (Singh et al 2015)
Natural vanillin was produced from isoeugenol as an alternative to botanical extracts
Biocatalyst, P. putida (HUT 8100) culture, was dispersed in inorganic buffer solution and isoeugenol was used with the aim of both, substrate and organic phase

Summary

Introduction

Vanillin (4-hydroxy-3-methoxybenzaldehyde) which naturally occurs in vanilla orchid pods, is one of the most important flavoring compounds (Singh et al 2015). Biphasic system (organic/inorganic) has been preferred in bio-flavor studies to overcome this problem In this method, a non-aqueous phase is used to sequester the substrate from aqueous solution that includes the cells. Bioconversion yield may be raised by manipulating oxygen transfer rate in medium according to organic phase features (Bicas et al 2010) It was investigated usage of biphasic system in various flavor production studies such as cinnamyl alcohol (Zhang et al 2020), 2-phenylethanol (Chreptowicz & Mierzejewska 2018), R-(+)-α-terpineol (Bicas et al 2010) and concluded that the method was very effective on raising catalytic performance of the cells. Unlike the other vanillin studies, Zhao et al (2005) used a biphasic medium containing 60% (v/v) isoeugenol and achieved to produce 32.5 g L-1 vanillin which is the highest in literature, according to our knowledge

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Results

Conclusion