Production of a biodegradable polyhydroxypropionate from glycerol using engineered bacteria

Purpose and goal

The project fulfilled the goal of developing an E. coli strain capable of producing PHP. The polymer could be extracted, purified and characterized. The work on developing L. reuteri also as a production host was not complete and requires alternative metabolic engineering strategies.

Results and expected effects

The project has resulted in a recombinant E. coli able to produce PHP. Expression of phaC and lack of PHP production in the recombinant L. reuteri suggests the need for further investigations. A process was designed for production of PHP from 3HPA using recombinant E. coli. PHP was extracted, purified and characterized Work is presented in 1 manuscript (in preparation), 1 Master thesis and 1 conference poster

Approach and implementation

Two strategies for microbial production of PHP were employed. In one, the entire metabolic pathway was engineered in E. coli by combining genes from different organisms. L. reuteri has all the enzymes needed except the last one for synthesis of PHP. More focus was put on E. coli as all the genetic engineering tools are available for the organism. Engineered cells were first grown and then induced for PHP accumulation by resting cells. Formation of PHP was confirmed by GC and NMR.