Separation by Size Exclusion: Selective Liquid-Phase Adsorption of l-Lysine from Lysine–Glucose Mixtures on Zeolites

Abstract

l-Lysine is an essential amino acid of great importance for the pharmaceutical and nutrition industries and is mainly produced by the fermentative conversion of d-glucose. The technological bottleneck for an efficient process is often the development of separation and purification technologies as they can account for 20–50% of the overall operation costs. Liquid-phase adsorption on zeolites is an energy-, resource-, and cost-saving alternative. Zeolites are a well-established and widely available class of adsorbents. In this research, a variety of commercial zeolites of different framework types with varying Si/Al ratios were used to investigate the adsorption of l-lysine from single-component solutions and lysine–glucose mixtures. l-Lysine recovery resulted in adsorption capacities of up to 169 mg g–1 on Hβ-30 in batch experiments. Zeolites showed high l-lysine selectivity in competitive adsorptions from lysine–glucose mixtures, outperforming previously reported adsorbents. Based on the analysis of adsorbent and adsorbate dimensions, a size-exclusion-based separation of l-lysine from d-glucose was proposed, which was found to be primarily responsible for the high l-lysine selectivity. Fourier transform infrared spectroscopy analysis allowed proposing a structure–adsorption relationship for l-lysine on zeolites. The transferability of the batch results to a continuous process was shown. In addition, a high desorption efficiency of up to 90% using water as the desorption solution could be achieved, complemented by successful recyclability tests over five consecutive adsorption–desorption cycles.

Respiration-based investigation of adsorbent-bioprocess compatibility

“…As a result, activated carbons 1 and 2 should be excluded from an application in a bioprocess with C. glutamicum DM1933 in CG-XII medium. Instead activated carbon 4 or the zeolite could be used, as they also showed good results in detailed investigations of lysine adsorption [ 32 , 43 ].…”

“…In this work, the bioprocess compatibility of three different types of adsorbents were investigated: activated carbons, HCPs and one zeolite. Their adsorption characteristics were investigated by cooperation partners and are in part already published [ 25 , 43 , 44 ]. An overview of all tested adsorbents, their adsorption capacities for the products of the three microbial model systems and the presentation of the data in the different figures is provided in Table 1 .…”

“…Adsorption capacities were determined in solutions with initial concentrations of 30 g/L lysine, 60 g/L itaconic acid (for activated carbons, HCPs 1 and 3 and zeolite) or 30 g/L itaconic acid (for HCPs 2 and 4) and 50 g/L 5-ketofructose. Desorption of products from the adsorbents was investigated and in part published by our project partners [43] Type C. glutamicum DM1933 treated with the best available adsorbents for lysine (Table 1) are displayed in Fig. 3.…”

Monte Carlo simulations of water pollutant adsorption at parts-per-billion concentration: A study on 1,4-dioxane

“…Crystalline porous materials like metal-organic frameworks (MOFs), covalent organic frameworks (COFs), carbon nanotubes, polyoxometalates, and zeolites, have revolutionized mixture adsorption separations through control of pore size 1 , entropy 2 , and binding strength 3 .…”

Enantioselective Recognition of L-Lysine by ICT Effect with a Novel Binaphthyl-Based Complex

“…In the human body, amino acids are important raw materials for protein synthesis and are equally important for human development, normal metabolism, and the continuation of life [ 10 ]. Lysine is a fatty amino acid and one of the basic essential amino acids for humans and mammals [ 11 , 12 , 13 , 14 ]. The body cannot synthesize it by itself, and it must be supplemented with food.…”