Comparison of production of gamma-decalactone via microbial biotransformation based on different adsorption-embedding systems.

Abstract

Gamma-decalactone (GDL) is an essential flavor additive with peach-aroma, which can be prepared via microbial biotransformation from ricinoleic acid (RA). The difficulty of RA dispersion in medium limited its utilization, which made the yield of GDL low. In this study, four adsorbent materials (AM) were investigated to increase RA distribution, including halloysite, clay, SUNSIL-130NP silica (130NP), and SUNSIL-130H silica (130H). They were compared with respect to their effects on the biotransformation process, and the mechanism of AM on productivity of Saccharomyces cerevisiae was revealed. Scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis were utilized to reveal the mechanism of AM effect on GDL production. The results showed that AM functioned as an adsorption and slow-releasing carrier of RA and cell immobilization. RA was crosslinked onto the surface of four AM via hydrogen bonds and the contact area between RA and yeast increased without negative viability effect. The best adsorption-embedding rate of RA to AM was 70.94% with 130H and the GDL yield improved to 2.79gL-1 . The highest conversion rate was 88.99% with halloysite at 36h. This study provides a potential strategy to improve GDL yield efficiently via biotransformation on an industrial scale.