Elsevier

Bioresource Technology

Volume 167, September 2014, Pages 219-225
Bioresource Technology

Nanofiltration, bipolar electrodialysis and reactive extraction hybrid system for separation of fumaric acid from fermentation broth

https://doi.org/10.1016/j.biortech.2014.06.010Get rights and content

Highlights

Abstract

A novel approach based on a hybrid system allowing nanofiltration, bipolar electrodialysis and reactive extraction, was proposed to remove fumaric acid from fermentation broth left after bioconversion of glycerol. The fumaric salts can be concentrated in the nanofiltration process to a high yield (80–95% depending on pressure), fumaric acid can be selectively separated from other fermentation components, as well as sodium fumarate can be conversed into the acid form in bipolar electrodialysis process (stack consists of bipolar and anion-exchange membranes).

Reactive extraction with quaternary ammonium chloride (Aliquat 336) or alkylphosphine oxides (Cyanex 923) solutions (yield between 60% and 98%) was applied as the final step for fumaric acid recovery from aqueous streams after the membrane techniques. The hybrid system permitting nanofiltration, bipolar electrodialysis and reactive extraction was found effective for recovery of fumaric acid from the fermentation broth.

Introduction

Organic acids are mainly produced by microbial fermentation (Deng et al., 2012) resulting in generation of fermentation broth containing organic salts and some impurities like sugars and mineral salts. In fact, many operations are necessary to separate and purify the final product (organic acid) from the fermentation broth. For example fumaric acid can be produced by fermentation in the presence of Escherichia coli species (Song et al., 2013). It was found that under aerobic conditions E. coli were able to produce 28 g/L of fumaric acid, however, during bacterial fermentation a substantial amount of acetic acid was formed. Nakajima-Kambe et al. (1997) tested the influence of temperature, pH and type of carbon sources (such as maleic, malonic, itaconic, adicipic and succinic acids) on the rate of the bioconversion. The highest fumaric acid productivity was obtained in the temperature range between 30 and 45 °C, at pH 7 and with maleic acid used as a carbon source. Under these conditions, above 40 g/L of fumaric acid and almost threefold less of l-malic acid, as a by-product, were obtained after 6 h of incubation. Xu et al. (2010) have reported that fumaric acid could be produced from two-stage utilization of corn straw in the presence of Rhizopus oryzae strain. The xylose-rich hydrolysates obtained as a result of acid hydrolysis of corn straw, were responsible for the growth of microorganisms. The corn straw left after acid hydrolysis was used in the next step for fumaric acid production in glucose-rich hydrolysates upon enzymatic hydrolysis. Under the optimal conditions the fumaric acid production reached up to 28 g/L. The protoplast fusion of R. oryzae and Rhizopus microsporus strains for fumaric acid production from glycerol was proposed by Kordowska-Wiater et al. (2012). It was shown that double fusion led to an increase in fumaric acid productivity in relation to the parental strains. Fermentation of glycerol as the only carbon source in the medium, resulted in formation of small amounts of lactic acid and around 30 g/L of fumaric acid. These reports imply that many additional operations are necessary to separate and purify the major product (an organic acid) from the broth. Da Silva and Miranda (2013) have suggested the application of adsorption/desorption on activated carbon and a weak base resin for the recovery of an organic acid from the broth. Zhang et al. (2012) have proposed a two-stage crystallization to extract glutamic acid from fermentation broth. By means of the proposed technique, glutamic acid was recovered in 83% in the first stage including isoelectric crystallization, while more than 70% of the remaining glutamic acid was separated in the second stage by evaporative crystallization. One of the techniques commonly used to purify organic acids from the broth is esterification. In other reports, Zhao et al. (2009) have presented the possibilities of lactic acid recovery from fermentation broth of kitchen garbage by esterification and hydrolysis. The process was carried out in two steps: first, lactate ester was produced by esterification of ammonium lactate of 96% yield, and then the lactate ester was purified and hydrolyzed to lactic acid in the presence of a cation-exchange resin.

In this investigation, a hybrid system consisting of three stages of nanofiltration (NF), bipolar electrodialysis (EDBM) and reactive extraction was proposed for separation of fumaric acid from the fermentation broth left after bioconversion of glycerol (Fig. 1).

At first, nanofiltration was performed as a pre-treatment step to concentrate organic acids and separate glycerol from the other components of the broth. Two types of devices were used at the nanofiltration stage: a laboratory setup equipped with a flat sheet polymeric membrane, and a pilot scale NF system equipped with a tubular ceramic membrane (Staszak et al., 2014). At the second stage, bipolar electrodialysis of the nanofiltration retentate, containing concentrated organic acids, was carried out, and after that reactive extraction of the nanofiltration retentate and diluate after bipolar electrodialysis were used to recover the residues of fumaric acid.

Section snippets

Materials

Two fermentation broths of different compositions coming from biotechnological conversion of glycerol were investigated. The research material was delivered by one of the collaborators in the frames of the project: “Biotechnological conversion of glycerol to polyols and dicarboxylic acids.” The method of fermentation is protected by the copyright (Kordowska-Wiater et al., 2012).

Various solvating (tributyl phosphate – TBP, mixture of trialkylphosphine oxides – Cyanex 923) or basic (trioctylamine

Calculations

The retention of organic acids obtained in nanofiltration process was determined according to the formula:R=1-CpCf·100%where Cp, Cf are the concentration of an organic acid in the permeate and in the feed solution, respectively.

The average value of the current efficiency was calculated on the basis of the following equation:CE=-F·z+·υ+·Vdil·ΔCdiln·I·Δt·100%where: F is a Faraday‘s constant [C/mol], z+, ν+ are ionic valence and number of cations, respectively, Vdil is the volume of diluate [L], Δ

Determination of fermentation broth composition by HPLC

Prior to separation, the components of fermentation broth were determined chromatographically.

The influence of the HPLC mobile phase composition on separation of fermentation broth compounds was checked. Concentration of sulfuric acid was changed between 1.25 and 5 mM, which corresponded to the pH of mobile phase between 2.7 and 2.1. The sulfuric acid concentration in the mobile phase was found to have a slight effect on the retention times of fumaric, succinic, citric, acetic, and cordycepic

Conclusion

A novel approach based on a hybrid system permitting the performance of nanofiltration, bipolar electrodialysis and reactive extraction is proposed for the recovery of fumaric acid from the fermentation broths resulting from bioconversion of glycerol. This hybrid system enables fumaric salt to be concentrated even up to 95% (depending on TMP), to be further converted to fumaric acid with AM BM stack in EDBM process. Finally, fumaric acid can be removed in a three-step reactive extraction with

Acknowledgements

This research was financially supported within the project “Biotechnological conversion of glycerol to polyols and dicarboxylic acids,” implemented within the Operational Programme-Innovative Economy, 2007–2013, co-financed by the European Union. PO IG 01.01.02.074/09.

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