Xylose-rich Horse Manure Hydrolysate as the Sole Carbon Source for Bacterial Production of Polyhydroxy Butyrate Using Engineered Escherichia coli

We investigated the possibility of using horse manure hydrolysates (HMH) as the sole carbon source for bacterial production of polyhydroxy butyrate (PHB) by engineered Escherichia coli. HMH was prepared by acid hydrolysis of horse manure. Over 90% of toxic furan byproducts were removed to yield detoxified HMH (D-HMH). Chemical analysis of hydrolysates revealed the presence of xylose and arabinose at high concentrations. E. coli BL21 strain was genetically engineered to produce PHB when D-HMH or xylose (control) were used as the sole carbon feedstock. Cells were incubated for both 48 and 72 h followed by PHB extraction. Molecular weight measurements and thermal characterization of the PHB produced were similar whether the cells were fed D-HMH or xylose. Our results lead to a facile method for valorization of manure by introducing its hydrolysates as a sustainable feedstock for bacterial production of PHB.

Automated summary

The study explored the use of horse manure hydrolysates as a sustainable feedstock for bacterial production of polyhydroxy butyrate. Genetically engineered E. coli strains were able to produce PHB using hydrolysates, showing similar results to using xylose as a carbon source. This research provides a facile method for valorization of manure by introducing its hydrolysates as a sustainable feedstock for PHB production.