Itaconic acid is a promising chemical that has a wide range of applications and can be obtained in large scale using fermentation processes. One of the most important uses of this biomonomer is the environmentally sustainable production of biopolymers. Separation of itaconic acid from the fermented broth has a considerable impact in the total production cost. Therefore, optimization and high efficiency downstream processes are technological challenges to make biorefineries sustainable and economically viable. This review describes the current state of the art in recovery and purification for itaconic acid production via bioprocesses. Previous studies on the separation of itaconic acid relying on operations such as crystallization, precipitation, extraction, electrodialysis, diafiltration, pertraction, and adsorption. Although crystallization is a typical method of itaconic acid separation from fermented broth, other methods such as membrane separation and reactive extraction are promising as a recovery steps coupled to the fermentation, potentially enhancing the overall process yield. Another approach is adsorption in fixed bed columns, which efficiently separates itaconic acid. Despite recent advances in separation and recovery methods, there is still space for improvement in IA recovery and purification.

In Colombia, coffee growers use a traditional method of fermentation to remove the cherry pulp surrounding the beans. This process has a great influence on sensory quality and prestige of Colombian coffee in international markets, but has never been studied. Here we use an Illumina-based amplicon sequencing to investigate bacterial and fungal communities associated with spontaneous coffee-bean fermentation in Colombia. Microbial-derived metabolites were further analysed by high–performance liquid chromatography and gas chromatography–mass spectrometry. Highly diverse bacterial groups, comprising 160 genera belonging to 10 phyla, were found. Lactic acid bacteria (LAB), mainly represented by the genera Leuconostoc and Lactobacillus , showed relative prevalence over 60% at all sampling times. The structure of the fungal community was more homogeneous, with Pichia nakasei dominating throughout the fermentation process. Lactic acid and acetaldehyde were the major end-metabolites produced by LAB and Pichia , respectively. In addition, 20 volatile compounds were produced, comprising alcohols, organic acids, aldehydes, esters, terpenes, phenols, and hydrocarbons. Interestingly, 56 microbial genera, associated with native soil, seawater, plants, insects, and human contact, were detected for the first time in coffee fermentation. These microbial groups harbour a remarkable phenotypic diversity and may impart flavours that yield clues to the terroir of Colombian coffees.

Itaconic acid (IA) is an unsaturated diacid, a promising compound that might replace part of the petrochemical-based monomers, such as acrylic acid, as a building block for polymers. Recent developments in biotechnology allow the efficient production of IA through fermentation processes. However, further enhancements are necessary in the downstream (recovery) of the product. This investigation examined the separation of IA by adsorption from aqueous solutions, using two types of commercial, strongly basic ion-exchange resins: Purolite A-500P and PFA-300. To evaluate the separation process, the following parameters were tested: pH (from 3.03 to 6.33), temperature (from 10 to 50 °C), and IA concentration (from 0.41 to 6.50 g·L–1). The Freundlich and Langmuir isotherms were shown to be good fits to the experimental data, and the adsorption kinetics for IA was found to follow a pseudo-second-order (PSO) model. After batch tests, continuous adsorption experiments were carried out using a fixed bed column, and a simplified mathematical model was developed and evaluated in order to determine the adsorption parameters. The experimental data obtained from the column tests were aligned with those obtained from the isotherms and batch simulations with PSO. The resin PFA-300 proved to be more efficient for IA recovery through adsorption, with a maximum capacity of 0.154 gIA.gresin –1 when compared to the resin A-500P, with a maximum capacity of 0.097 gIA.gresin –1. Both resins have high affinity for the solute, being half-saturated with equilibrium concentrations below 0.25 g·L–1 of acid.

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