The challenges and prospects of Escherichia coli as an organic acid production host under acid stress

Abstract

Objective Organic acids have a wide range of applications and have attracted the attention of many industries, and their large-scale applications have led fermentation production to low-cost development. Among them, the microbial fermentation method, especially using Escherichia coli as the production host, has the advantages of fast growth and low energy consumption, and has gradually shown better advantages and prospects in organic acid fermentation production. Importance However, when the opportunity comes, the acidified environment caused by the acid products accumulated during the fermentation process also challenges E. coli. The acid sensitivity of E. coli is a core problem that needs to be solved urgently. The addition of neutralizers in traditional operations led to the emergence of osmotic stress inadvertently, the addition of strong acid substances to recover products in the salt state not only increases production costs, but the discharged sewage is also harmful to the environment. Elaboration This article summarizes the current status of the application of E. coli in the production of organic acids, and based on the impact of acid stress on the physiological state of cells and the impact of industrial production profits, put forward some new conjectures that can make up for the deficiencies in existing research and application. Implication At this point, the diversified transformation of E. coli has become a chassis microbe that is more suitable for industrial fermentation, enhancing industrial application value. Key points • E. coli is a potential host for high value-added organic acids production.• Classify the damage mechanism and coping strategies of E. coli when stimulated by acid molecules.• Multi-dimensional expansion tools are needed to create acid-resistant E. coli chassis.

A metabolic sum rule dictates bacterial response to short-chain fatty acid stress

“…Particularly in biotechnology, the production of recombinant proteins by E. coli is limited by the acetic acid excreted ( 6, 9, 10 ). Furthermore, the industrial applications of high-value SCFAs produced by microbes is of significant interest, but the sensitivity of microbes to SCFAs remains a core problem in managing production costs ( 11 ).…”

[NiFe] Hydrogenase Accessory Proteins HypB–HypC Accelerate Proton Conversion to Enhance the Acid Resistance and d-Lactic Acid Production of Escherichia coli

“…1 According to a new report by Grand View Research, Inc., the global lactic acid market is expected to reach $5.02 billion by 2028. 2 D-lactic acid is an important synthetic monomer that can be mixed with L-lactic acid in a specified ratio to form a polymer compound poly(D,L-lactic acid) (PDLLA) to improve the thermal stability of PLA, up to 230 °C. 3−5 As a result, the demand for D-lactic acid has increased significantly.…”

“…Biodegradable polymers polylactic acid (PLA) which made of lactic acid as a monomer have attracted attention for their advantages in biocompatibility, bacterial resistance, flame retardancy, and ultraviolet resistance . According to a new report by Grand View Research, Inc., the global lactic acid market is expected to reach $5.02 billion by 2028 − As a result, the demand for d -lactic acid has increased significantly …”

“…d -Lactic acid generated by microbial fermentation maximizes the product titer and purity required for PLA synthesis, which has been realized in Sporolactobacillus, Klebsiella, and Escherichia coli. ,− Among them, E. coli exhibits the advantages of low nutrient requirements and a short fermentation cycle, but its sensitivity to acid is also a typical problem. , The accumulation of acidic metabolites will cause the pH of the environment to drop rapidly and disrupt the intracellular balance.…”

“…d -Lactic acid generated by microbial fermentation maximizes the product titer and purity required for PLA synthesis, which has been realized in Sporolactobacillus, Klebsiella, and Escherichia coli. ,− Among them, E. coli exhibits the advantages of low nutrient requirements and a short fermentation cycle, but its sensitivity to acid is also a typical problem. , The accumulation of acidic metabolites will cause the pH of the environment to drop rapidly and disrupt the intracellular balance. In order to combat this adverse survival environment, cells will allocate more energy to regulate the expression of antacid functional factors and induce protein, − which will lead to a significant decrease in the physiological activity and fermentation capacity of the cells.…”