Direct Extraction of Fumaric Acid from Rhizopus oryzae Suspensions-Interfacial Mass Transfer.

Dan Cascaval,Alexandra Tucaliuc,Anca-Irina Galaction,Lenuta Kloetzer

doi:10.3390/biom11111563

Abstract

Experimental studies on the reactive extraction of fumaric acid with Amberlite LA-2 from Rhizopus oryzae suspensions using three solvents with different dielectric constants varying from 9.08 to 1.90 (dichloromethane, n-butyl acetate, and n-heptane, respectively) underlined the particular behavior of the extraction system in the presence of fungal biomass. The interfacial mass flow of the reaction product was found to be significantly affected by the biomass, due mainly to its adsorption onto the phase separation interface, this leading to the appearance of a physical barrier against the solute’s transfer. However, the magnitude of the adsorption phenomenon was found to depend on Rhizopus oryzae’s affinity for the solvent phase, which increased significantly from dichloromethane to n-heptane. The negative influence of the biomass on the interfacial mass transfer can be partially counteracted by adding 1-octanol into the organic phase, improving the solvent’s ability to solve the fumaric acid–Amberlite LA-2 complex and simplifying the reactive extraction mechanism, effects that were found to be more important for low-polar solvents. Consequently, for the same mixing intensity, the maximum amplification factor was reached for n-heptane, its value being almost 5–6 times higher than that obtained for dichloromethane and over 2 times higher than that obtained with n-butyl acetate.

Highlights

Experiments previously carried out on the separation of fumaric acid from pure and viscous aqueous solutions by reactive extraction indicate that the process efficiency is controlled by the pH value and viscosity of the aqueous phase, the Amberlite LA2’s concentration in the organic phase, and the organic phase’s polarity [8]
The interfacial reaction between fumaric acid and Amberlite LA-2 can be described by the general mechanism [8]: R(COOH)2(aq) + p Q(o) R(COOH)2 ·Qp(o) where R(COOH)2 denotes the fumaric acid and Q denotes the extractant
To mathematically describe the cumulative influences of solvent polarity, mixing intensity, and Rhizopus oryzae concentration on the solute interfacial mass flow from the fungal suspension to the organic phase, we propose two models for both extraction systems, namely without and with 1-octanol

Summary

Introduction

A naturally occurring organic acid, is an important platform molecule with a broad range of applications in the food industry (a preservative for food and beverages, a base for artificial flavors, a coagulant, a regulator of acidity, an additive for ruminant feed, etc.), healthcare and biomedical fields, and the chemical industry (raw material for the production of organic acids, dyes, mordants, polyalcohols, biodegradable polymers, polyester, and alkyd resins and compounds used in medicine) [1,2]. Over 300,000 tons of fumaric acid is consumed, this amount being produced mainly by chemical synthesis starting from benzene, n-butane, or maleic anhydride, and by fermentation using Rhizopus spp., mainly Rhizopus oryzae and Rhizopus arrhizus [2,3,4,5,6]

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