Metabolic engineering combined with site-directed saturated mutations of α-keto acid decarboxylase for efficient production of 6-aminocaproic acid and 1,6-hexamethylenediamine.

6-Aminocaproic acid (6ACA) and 1,6-hexamethylenediamine (HMDA) are key precursors for nylon synthesis, and both are produced using petroleum-based chemical processes. However, the utilization of bio-based raw materials for biological production of monomers is crucial for nylon industry. In this study, we demonstrated that metabolic engineering of Escherichia coli and selected mutations of α-keto acid decarboxylase successfully synthesized 6ACA and HMDA.

Efficient bio-production of glutaric acid by a metabolically engineered Escherichia coli LQ-1 based on a novel nitrogen source feeding strategy.

As an important five-carbon platform chemical to synthesize polyesters and polyamides, glutaric acid is widely used in numerous biochemical fields such as consumer goods, textile, and footwear industries. However, the application of glutaric acid is limited by the low yield of its bio-production. In this study, a metabolically engineered Escherichia coli LQ-1 based on 5-aminovalerate (AMV) pathway was used for glutaric acid fed-batch fermentation.

[Heterologous expression and characterization of Klebsiella oxytoca lysine decarboxylase].

Cadaverine is a biogenic amine that has the potential to become an important platform chemical for the production of industrial polymers, such as polyamides and polyurethanes. We reported here a lysine decarboxylase from Klebsiella oxytoca. The lysine decarboxylase from Klebsiella oxytoca was cloned to Escherichia coli to get the strain LN18.

Improved microbial fuel cell performance by encapsulating microbial cells with a nickel-coated sponge.

Development of novel anodic materials that could facilitate microbial biofilm formation, substrate transfer, and electron transfer is vital to enhance the performance of microbial fuel cells (MFCs). In this work, nickel-coated sponge, as a novel and inexpensive material with an open three-dimensional macro-porous structure, was employed as an anode to encapsulate microbial cells. Compared with planar carbon paper, the nickel-coated sponge did not only offer a high surface area to facilitate microbial cells attachment and colonization but also supported sufficient substrate transfer and electron transfer due to multiplexed and highly conductive pathways.

[Metabolic flux analysis of L-valine fermentation in Corynebacterium glutamicum].

In industrial fermentation of amino acids the cells are often forced to synthesize the biochemicals excessive of their physiological needs. The knowledge of metabolic networks and their regulation relevant usually come from biochemical research, especially from enzymology, not from engineering study. To enrich the knowledge of metabolic sub-network of L-valine syntheses for higher production of L-valine, Corynebacterium glutamicum AS1.