Oral Presentation 2-01
Aromatic Compounds from Sugar via Bioconversions by the
Solvent-tolerant Bacterium Pseudomonas putida S12
Jan Wery, Karin Nijkamp, Nick Wierckx, Rita Volkers, and Jan de Bont*
TNO Environment, Energy and Process Innovation
Department of Environmental Biotechnology,
Phone: 31-555493920
Fax: 31-555493523
E-mail: j.debont@mep.tno.nl
The use of
bio-feeds rather than fossil resources is an attractive option for developing
new and economically attractive biocatalytic synthesis routes and because CO2
emissions can be minimized. Recent developments in life sciences, and in
particular in integrated genomics technologies, have revolutionized the toolbox
available to construct producing organisms. Integrated downstream processing of
products via innovative process control and separation technologies has to be
applied in realizing economic production methods.
Whole-cells are
particularly useful if reactions require multi-step systems as is the case when
producing chemicals in a multistep fashion from renewable natural sources
(sugars) into, for instance, aromatic compounds. A major inherent obstacle in
whole-cell production is the toxicity of chemicals such as aromatics to living
cells.
Solvent-tolerant Pseudomonas putida strains have specific physiological responses to cope with
devastating effects of toxic products and can even grow in the
presence of a separate phase of toluene. They consequently are relatively good
hosts in the production of chemicals that are toxic to most other microbes.
The presentation
deals with the following aspects:
1.
Short description of the
physiological basis of tolerance to chemicals in the host Pseudomonas putida S12.
2.
General approach based on integrated
genomics in optimizing product formation from sugars.
- Random mutagenesis of strain S12 to overproduce a metabolite from
glucose
- High throughput screening for optimized producers
- Comparative genomics (proteomics and transcriptomics)
- Targeted improvement of optimized mutants as characterized via the
genomics approach
- Introduction relevant heterologous genes in the host P. putida S12
to convert a central
metabolite into a desired
aromatic compound
3.
Phenol from glucose as a proof of
principle for the production of a bulk chemical from the
renewable feedstock glucose. Beyond phenol, aromatic compounds slightly
more complex than phenol, and consequently of more economic interest, will be
considered.
4. Options for
utilizing hydrolysates from lignocellulosic biomass as feedstock rather than
glucose.