Determination of the Reaction Yield during Biotransformation of the Volatile and Chemically Unstable Compound β-Ionone by Aspergillus niger

Abstract

Biotransformation of beta-ionone by Aspergillus niger IFO 8541 was a complex system, due to the low precursor solubility in water (0.88 mol/m(3)) which gave a two-phase liquid system, its high volatility (vapor pressure 7.2 Pa), and its poor chemical stability. A dynamic model, considering transfers between organic, aqueous, and gas layers, was established. It also took into account the decrease in organic layer area exchange during a process, due to progressive precursor disappearance. Its solving needed separate determination of two parameters. The first-order kinetic constant for chemical degradation, K(1), was estimated from side experiments involving a model system at thermodynamic equilibrium; its value was found to be close to 4.17 x 10(-)(6) s(-)(1). The volumetric transfer coefficient between gas and aqueous phase was estimated by analogy with results obtained for oxygen transfer. Results obtained demonstrated high liquid-gas transfer rates, while liquid-liquid transfers were severely limited. These data were then used to estimate the true yield of a biotransformation experiment, which was found to be close to unity.

Optimization of isonovalal production from α-pinene oxide using permeabilized cells of Pseudomonas rhodesiae CIP 107491

“…In other words, no phase-transfer limitation could be shown. This was quite surprising, because such limitation could occur even with reaction rates considerably lower (Grivel et al 1999;Grivel and Larroche 2001). This behavior probably resulted from the fact that the biphasic medium appeared to be an oil-in-water emulsion, thus giving a large exchange area (Gargouri 2001).…”

Carotenóides: propriedades, aplicações e biotransformação para formação de compostos de aroma

“…Os compostos originados da biotransformação atingiram a concentração de 3,5 g/L após 400 h de reação. Compostos como 4-oxo-β-ionona, 2-hidróxi-β-ionona, 4-hidróxi-β-ionona, 2-oxo-β-ionona e 4-hidróxi-5,6-epóxi-β-ionona foram formados através da biotransformação 26 . Um tipo de monooxigenase do citocromo P450 de Bacillus megaterium (P450 BM-3) possui baixa atividade de hidroxilação de β-ionona.…”

Bio-oxidation of Terpenes: An Approach for the Flavor Industry

“…139 The physicochemical parameters of that system were analyzed elsewhere. 140 In their paper, very interesting for its originality, Krings et al 141 reported the screening of submerged microbial cultures able to oxifunctionilize the sesquiterpene R-farnesene (59). One culture, identified as A. niger, exhibited the most versatile and attractive flavor profile.…”

“…The best yield, 3.5 g·L −1 , was obtained after 400 h of reaction . The physicochemical parameters of that system were analyzed elsewhere . In their paper, very interesting for its originality, Krings et al reported the screening of submerged microbial cultures able to oxifunctionilize the sesquiterpene α-farnesene ( 59 ).…”