Comprehensive assessment of the l-lysine production process from fermentation of sugarcane molasses

Abstract

L-Lysine is an essential amino acid that can be produced by chemical processes from fossil raw materials, as well as by microbial fermentation, the latter being a more efficient and environmentally friendly procedure. In this work, the production process of L-lysine-HCl is studied using a systematic approach based on modeling and simulation, which supports decision making in the early stage of process design. The study considers two analysis stages: first, the dynamic analysis of the fermentation reactor, where the conversion of sugars from sugarcane molasses to L-lysine with a strain of Corynebacterium glutamicum is carried out. In this stage, the operation mode (either batch or fed batch) and operating conditions of the fermentation reactor are defined to reach the maximum technical criteria. Afterwards, the second analysis stage relates to the industrial production process of L-lysine-HCl, where the fermentation reactor, upstream processing, and downstream processing are included. In this stage, the influence of key parameters on the overall process performance is scrutinized through the evaluation of several technical, economic, and environmental criteria, to determine a profitable and sustainable design of the L-lysine production process. The main results show how the operating conditions, process design, and selection of evaluation criteria can influence in the conceptual design. The best plant design shows maximum product yield (0.31 g L-lysine/g glucose) and productivity (1.99 g/L/h), achieving 26.5% return on investment (ROI) with a payback period (PBP) of 3.8 years, decreasing water and energy consumption, and with a low potential environmental impact (PEI) index.

Evolving a New Efficient Mode of Fructose Utilization for Improved Bioproduction in Corynebacterium glutamicum

“…Metabolic engineering was used to broaden the substrate spectrum of C. glutamicum toward second generation feedstocks such as non-food wastes from biodiesel (glycerol) (Rittmann et al, 2008) or hemicellulose biomasses (xylose and arabinose) (Zhao et al, 2018). Yet, the sugars glucose, derived from starch hydrolysates as well as sucrose and fructose derived from molasses, are still the preferred carbon sources for amino acid production (Anaya-Reza and Lopez-Arenas, 2017). The decrease in L-lysine titers when fructose is used instead of glucose is drastic, resulting in a 40-75% lower L-lysine yield (Georgi et al, 2005).…”

Metabolic engineering of carbohydrate metabolism systems in Corynebacterium glutamicum for improving the efficiency of l-lysine production from mixed sugar

“…Therefore, reuse of molasses is important for sugar industry to improve economic returns. At present, molasses is one of the main feedstock for amino acids production (e.g., l-lysine [10,29], l-glutamate [30], poly-γ-glutamic acid [31]), because its main component is sucrose [7]. Sucrose can be easily hydrolyzed to glucose and fructose [7].…”