Engineering Halomonas bluephagenesis as a chassis for bioproduction from starch

Area of Science:

• Industrial Biotechnology
• Microbial Engineering
• Biocatalysis

Background:

• Halomonas bluephagenesis is a robust bacterium capable of growth under unsterile conditions.
• Current industrial enzyme production often relies on costly substrates and less robust organisms.
• Engineering H. bluephagenesis could reduce production costs for bulk hydrolytic enzymes and other bioproducts.

Purpose of the Study:

• To engineer H. bluephagenesis as an extracellular hydrolytic enzyme producer.
• To enable H. bluephagenesis to utilize low-cost substrates like starch.
• To establish H. bluephagenesis as a versatile chassis for the Next Generation Industrial Biotechnology (NGIB).

Main Methods:

• Constructed and optimized a modularized secretion machinery in H. bluephagenesis.
• Utilized codon-optimized genes encoding α-amylase from Bacillus licheniformis.
• Screened signal peptides and linkers using super-fold green fluorescence protein (sfGFP) for enhanced secretion.

Main Results:

• Achieved a 7-fold enhancement in sfGFP secretion using optimized signal peptides and linkers.
• Engineered H. bluephagenesis successfully produced polyhydroxybutyrate (PHB), P34HB, PHBV, ectoine, and L-threonine from starch.
• Recombinant H. bluephagenesis TN04 reached approximately 10 g/L cell dry weight with 51% PHB content using corn starch.

Conclusions:

• Halomonas bluephagenesis can be engineered as an effective producer of extracellular enzymes.
• The engineered bacterium can utilize low-cost starch as a substrate for producing multiple valuable products.
• H. bluephagenesis presents a promising chassis for cost-effective and robust industrial biotechnology applications.