The FeedstocksUnited technology is based on a concept which envisages the trimeric one-carbon (C1) compound trioxane as the fermentable derivative of a range of C1-compounds. The concept connects established industrial chemistry to existing biotechnology routes to enable large scale C1-feedstocks-based bioproduction (see figure below).
Presently trioxane is chemically produced at large scale from methane via syngas, methanol and formaldehyde. It can thus be considered as a storage molecule into which these C1-compounds can be funneled. Wastes such as non-food biomass and industrial off-gases, can also be fed into trioxane via syngas.
Currently, trioxane is used as monomer in the manufacture of polyoxymethylene (POM), at a scale of ~500,000 tons/year.
Trioxane has favorable characteristics that makes it a very suitable feedstock for straightforward fermentation of a range of organic products:
- It has the same oxidation/reduction level as sugars, whereas methane and methanol are more reduced.
- Trioxane is a stable solid that dissolves very well in water.
- Its density is about 1.2 kg/l, melting point is ~60⁰C.
- It is not toxic to microbes.
- It is available as a clean stream which is very relevant in view of downstream processing of bioproducts.
- No contamination during fermentation.
Based on these characteristics, trioxane as feedstock in industrial fermentations is the solution in resolving serious issues in current C1-feedstocks and/or biomass waste-fermentations, which are:
- Very high oxygen demand during fermentation due to reduced nature of the feedstocks (also see Technical).
- Poor solubility and mass transfer of gaseous feedstocks in fermentation.
- Very high heat generation during fermentation.
- Impure product streams, leading to complex and costly purification.
- Toxicity of methanol and particularly formaldehyde.
- Safety risks such as explosivity.
Consequently, trioxane can act as an ideal fermentation feedstock (like sugar), enabling large-scale bioproduction of a range of products, provided it can be utilized as a carbon and energy source by the producing micro-organism. However, no micro-organisms and enzymes have been described that break down trioxane. FeedstocksUnited has obtained such a micro-organism possessing the suitable enzymes.
The core of our technology concerns the enzymatic breakdown of trioxane for further metabolism into biomass and products.
Status of the work
Key milestones accomplished:
- Demonstration of microbial degradation of trioxane in the absence of oxygen.
- A pure culture of a relevant bacterium has been isolated and its genome has been sequenced.
- Genetic analyses pointing to specific enzymes.
- A patent application has been filed on the technology with claims covering genes, organisms and processes.
Next steps in technology development
The biology of methane and other C1-compound utilization as well as of trioxane is such that the pathways meet at the level of formaldehyde as the central metabolite. Hence, by introducing the genes for trioxane degradation into C1-utilizing micro-organisms they are expected to grow on it. Micro-organisms already optimized for bioproductions from e.g. methane or methanol are good targets for our technology.
Accordingly, a key aspect in near-future work will be establishing functional expression of trioxane-degrading enzymes in established production hosts leading to production of relevant products, like protein, organic acids and alcohols.