Methanol-based cadaverine production by genetically engineered Bacillus methanolicus strains

Area of Science:

• Biotechnology
• Metabolic Engineering
• Synthetic Biology

Background:

• Methanol is a promising substrate for producing valuable chemicals like amino acids and polyamines.
• Bacillus methanolicus is a methylotrophic and thermophilic bacterium suitable for biotechnological applications.

Purpose of the Study:

• To engineer Bacillus methanolicus as a microbial cell factory for 1,5-diaminopentane (cadaverine) production from methanol.
• To evaluate the efficiency of heterologous lysine decarboxylase expression and L-lysine overproduction in B. methanolicus for cadaverine synthesis.

Main Methods:

• Heterologous expression of Escherichia coli cadA and ldcC genes in Bacillus methanolicus.
• Cultivation of engineered B. methanolicus at 50°C under shake flask and high-cell density fed-batch methanol fermentation conditions.
• Analysis of cadaverine production levels and investigation of cadaverine tolerance.

Main Results:

• Both heterologously expressed CadA and LdcC enzymes were functional in B. methanolicus.
• Expression of cadA led to cadaverine production up to 500 mg/L in shake flasks.
• A concentration of 11.3 g/L cadaverine was achieved via fed-batch methanol fermentation.
• Efficient cadaverine production impacted L-lysine biosynthesis feedback regulation.
• B. methanolicus demonstrated comparable cadaverine tolerance to E. coli and C. glutamicum.

Conclusions:

• Bacillus methanolicus can be successfully engineered for microbial production of 1,5-diaminopentane (cadaverine) from methanol.
• This study is the first to demonstrate cadaverine production from methanol using a microbial host.
• B. methanolicus is a viable alternative host for producing platform chemicals, comparable to established hosts like E. coli and C. glutamicum.