First, this technology roadmap is given a clear and unique identifier:
This indicates that we are dealing with a “level 2” roadmap at the product level, where “level 1” would indicate a market level roadmap, and “level 3” or “level 4” would indicate an individual technology roadmap within PHA manufacturing.

Plastic pollution. Credit: ead72 - stock.adobe.com Copyright: ©ead72 - stock.adobe.com
The problem of plastic accumulation in the natural environment is becoming a high profile problem. This is because oil-based plastics, while they are cheap and have good material properties, do not biodegrade.
One potential answer to this problem is bioplastics. The term bioplastics covers a lot of different types of materials, some of which are bio-based (i.e. generated from biological feedstocks) but not biodegradable, some of which are biodegradable but not biobased, and some that are both. One family of bioplastics that are bio-based AND biodegradable is PHAs (polyhydroxyalkanoates).

PHAs have the potential to replace oil-based plastics in terms of material properties! As one can see from the two images below, the range of properties that PHAs (blue) shows sizable overlap with the range of properties that oil-based plastics can exhibit.


One of the most exciting prospects is a variant of PHA called P(3HB). A comparison of properties with one of the most common forms of oil-based plastic, or polypropylene, is included below. In 2019 alone, a total of 16.8 billion pounds or 7.6 million tonnes of non-biodegradable polypropylene was produced. Imagine if this amount could be shifted to a biodegradable plastic instead!
| Property | P(3HB) | PP |
|---|---|---|
| Melting temperature (°C) | 175-182 | 171-186 |
| Glass-transition temperature (°C) | 4 | -10 |
| Density (g/cm3) | 1.25 | 0.92 |
| Crystallinity (%) | 65-80 | 65-70 |
| Young's modulus (GPa) | 3.5-4 | 1.7 |
| Tensile strength (MPa) | 40 | 38 |
| Extension to break (%) | 6-8 | 400 |
| Solvent resistance | poor | good |
| Ultraviolet resistance | good | poor |
| Oxygen permeability (cm3 m-2 atm-1 d-1) | 45 | 1700 |
| Biodegradability | excellent | poor or non-existent |
| Cost ($/kg) | 3.0-6.1 | 1.3-1.9 |
Sources:
As we can see from the table above, P(3HB) compares quite favorably to PP with regard to many mechanical properties and biodegradability. Of course, there are some properties that P(3HB) doesn't match well to - solvent resistance, extension to break, and oxygen permeability to name a few. As the science evolves, those gaps may close. The biggest barrier to increasing adoption is evidenced by the last row - the cost of P(3HB) is nearly 4x the cost of PP at present.
Unfortunately, PHAs currently are not competitive on a cost basis with oil-based plastics due to the high cost of manufacturing them. In fact, PHAs are only competitive with oil-based plastics when the price of oil is high. When the price of oil is low, PHA (and other bioplastics producers) suffer.

In this graph, we see a trend of oil prices (using Brent crude as a market) for the last several years. When the price of Brent crude fell in early 2014, the price of oil-based plastics fell in proportion. When the price of oil-based plastics fell, it led to several PHA bioplastics producers to go out of business because they could not produce PHA at a cost-competitive price with oil-based plastics. We want to break this dependence on oil prices. We propose a roadmap to reduce the cost of manufacturing PHA to parity or better with oil-based plastics.


The technology hierarchy tree shows the levels of each technology and what is contained in each level of technology. We can also depict the interdependencies between the technologies as a DSM (design structure matrix). The way to interpret this DSM is the inputs are on the rows. For example, 3OPH (PHA producing engineered organisms) affects the technology selected for the 3FPH (fermentation), 3PPH (precipitation), 3SPH (sterilization), and 3XPH (separation) but is not itself affected by the technology selected for these steps.
Please note that interdependencies were only captured between levels (i.e. at level 2 or at level 3, but not crossing between level 2 and 3).
This DSM highlights how important the 3OPH and 3FPH technologies are to the overall process - they affect the rest of the process steps, but they are not affected in turn.
The level 4 technologies (4XXX) are specific variants of the level 3 technologies (3XXX) and as such are not depicted here.
We provide an Object-Process-Diagram (OPD) of the 2MPH technology in the figure below. This diagram captures the main object of the technology (PHA bioplastics manufacturing). Please draw your attention to the right side of the diagram to see current PHA bioplastics manufacturing operators. Then, please draw your attention to the bottom section of the diagram to see the different figures of merit.
High level OPM for 2MPH
An Object-Process-Language (OPL) description of this OPD is auto-generated and given below. It reflects the same content as the previous figure, but in a formal natural language.
The 2MPH technology, the production process itself, is typically shown as below:
Generalized version of the PHA bioplastics manufacturing process (non-solvent version)
Source: Chen, Guo-Qiang. (2009). Industrial production of PHA. 10.1007/978-3-642-03287-5_6.
We also provide a OPD version of the above, including the high level process steps that make up PHA bioplastics manufacturing.
An Object-Process-Language (OPL) description of this OPD is auto-generated and given below. It reflects the same content as the previous figure, but in a formal natural language.
The table below show a list of different FOMs by which PHAs and the PHA manufacturing process can be assessed.
| Grouping | Figure of Merit (FOM) | Calculation Method | Reference value for the family of PHA polymers |
|---|---|---|---|
| Cost | Cost of manufacturing [$/kg of PHA bioplastics yielded] | For a given quantity (kg) of PHA bioplastics produced, the total cost of all variable inputs required (feedstock biomass, energy, labor and utilities) to produce that quantity divided by the quantity of PHA bioplastics produced. | $3 - 6/kg PHA (2017, versus $1.3 - 1.9/kg for oil-based plastics) |
| Sustainability | Biodegradability (%) | Measure the CO2 evolved by a given quantity of PHA bioplastics and compare it to the amount of CO2 evolved by the same amounts of starch and PE (polyethylene) respectively. | 68.3% for P(3HB) (2012) |
| Sustainability | CO2 intensity [kg CO2/kg PHA yielded] | For a given quantity (kg) of PHA produced, the total CO2 emitted during manufacturing to produce that quantity divided by the quantity of PHA produced. | 1.96 kg CO2/kg PHA (2009) |
| Sustainability | Water intensity [kg water/kg PHA] | For a given quantity (kg) of PHA produced, the total amount of water (kg) consumed divided by the quantity of PHA produced. | 150 kg H2O/kg PHA (2009) |
| Performance | Tensile strength [MPa] | Tensile strength of the PHA manufactured | 0 - 45 MPa (2018) |
| Performance | Young’s modulus (GPa) | Young’s modulus of the PHA manufactured | 0 - 3.5 GPa (2018) |
| Performance | Minimum and maximum operating temperature (degC) | Minimum and maximum operating temperature of the PHA manufactured | 40 - 110 degC (2018) |
| Performance | Elongation at break (%) | Elongation at break of the PHA manufactured as a % of the original length of the PHA | 0 - 1000% (2018) |
Our research has revealed that the PHA manufacturing process itself does not affect the sustainability and performance FOMs listed above. Rather, these are properties inherent to the type of PHA formed. The family of PHA polymers is large, and each of the members have their own mechanical properties, just like the family of oil-based plastics (HDPE vs LLDPE, etc.). Therefore, the cost of manufacturing, which IS affected by the choices made when designing the PHA manufacturing process, will be the focus of this roadmap and analysis.

This first chart shows how one of the most important FOMs, the cost to manufacture PHA as reported in literature, has varied over the past 30+ years.

This graph zooms into the last 20 years of reported PHA price and compares it to the cost of PP, an oil-based plastic. The current goal is to get the cost of PHA to at or below the cost of the oil-based plastics (like PP, or polypropylene).
| Number | Strategic Driver | Alignment and Targets |
|---|---|---|
| 1 | To develop a process to manufacture PHAs with desirable properties at a price point competitive with existing oil-based plastics. | This roadmap will target the design of a manufacturing process that will bring the cost per KG of P(3HB) to ~$1.5/kg or less, which is about 50% lower than the current achievable cost to produce P(3HB) - $3-6/kg. This driver is currently aligned with the PHA bioplastics manufacturing technology roadmap. |
| 2 | To develop a process to manufacture PHAs that are designed to be recovered via composting (to ensure the carbon stays fixed and doesn't go into the atmosphere as CO2) | The technology roadmap will target optimizing the physical and biodegradability properties of PHAs to ensure they can be sorted and recovered at end-of-life. This driver is not currently aligned with the PHA bioplastics manufacturing technology roadmap as it is considered out of scope at this time. |
The list of drivers shows that our company views PHA bioplastics as a promising industry with a lot of potential. Therefore, our company wants to develop the PHA bioplastics manufacturing process such that it yields bioplastics that are competitive with oil-based plastics on the basis of both material properties and cost. In order to do so, our technology roadmap introduces a technical model and some analysis using a governing equation for the cost of bioplastics manufacturing. The FOM target for the production cost of P(3HB), the PHA variant of interest since it is a direct competitor with PP (polypropylene), is at or below ~$1.5/kg in order to reach near-parity with the current market price of PP resin. This roadmap is aligned with this driver. This means that the analysis, technology targets, and R&D projects contained in our roadmap (and hopefully funded by the R&D budget) support the strategic ambition stated by driver 1.
However, the second driver, focused on managing end-of-life PHA bioplastics to ensure the carbon stays fixed, is out of scope and not currently aligned with this roadmap.
Before we introduce the positioning of our company, we will first introduce the landscape of options to produce our reference PHA, P(3HB).
This first table is based on academic and simulation data - the production cost is calculated via simulation and economic evaluation for a 100,000 tonnes/year P(3HB) plant.
| Strain | PHA produced | Fermentation strategy | Substrate | PHA content (%) | Productivity (g- L-1-hr-1) | Yield ([g PHA]/[g carbon]) | Production cost ($/kg) |
|---|---|---|---|---|---|---|---|
| A. latus | P(3HB) | Fed-batch | Sucrose | 50 | 3.97 | 0.17 | 8.3 |
| A. latus | P(3HB) | Fed-batch | Sucrose | 88 | 4.94 | 0.42 | 2.6 |
| E. coli | P(3HB) | Fed-batch | Glucose + YE + CSL + casein hydrolysate | 72.3 | 1.98 | 0.29 | 5.37 |
| E. coli | P(3HB) | Fed-batch | Glucose | 77 | 3.2 | 0.27 | 4.91 |
| M. organophilum | P(3HB) | Fed-batch | Methanol | 52 | 1.86 | 0.19 | 6.69 |
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Source:
In this table, we begin to see some of the factors and choices that influence the price. For example, how does the choice of feedstock affect the price? The strain of bacteria? The PHA content? etc. We see that one A. latus process near the top is much closer to our goal of ~$1.5/kg P(3HB) or less. Why is this?
Within this relatively small data set alone, we can observe certain patterns in the data. For example, the A. latus option that is $2.6/kg has a much higher PHA content, productivity, and yield compared to the first A. latus option that is $8.3/kg. Indeed, between these two A. latus options, the only difference was the application of a nitrogen limitation during fermentation that significantly boosted the content, productivity, and yield.
However, if we compare the $8.3/kg A. latus option with the $4.91/kg E. coli option, we see this E. coli option has significantly higher PHA content and productivity compared to the $8.3/kg A. latus option, but the increase in yield is smaller than the difference between the two A. latus options. The simulated price of this E. coli option ($4.91/kg) is indeed lower than the $8.3/kg reported for the A. latus option, but the price of this E. coli option is not as low as the $2.6/kg A. latus option. This seems to suggest that changes in the yield has a relatively bigger effect on the production cost than the other two parameters (content and productivity). This will be verified in the next section.
This second table follows a similar format, but this time, it reports data from large scale commercial PHA producers. Because this is commercial data, the production costs are not freely available. However, the other parameters (cell content, productivity, and yield) are reported.
| Strain | PHA produced | Fermentation strategy | Substrate | PHA content (%) | Productivity (g- L-1-hr-1) | Yield ([g PHA]/[g carbon]) | Production cost ($/kg) |
|---|---|---|---|---|---|---|---|
| R. eutropha ** | P(3HB) | no data | Glucose | 73.8 | 2.42 | 0.32-0.48 | - (commercial data) |
| P. cepacia | P(3HB) | no data | Xylose | 60 | no data | 0.11 | - (commercial data) |
| A. latus | P(3HB) | no data | Sucrose | 50 | 3.97 | 0.40 | - (commercial data) |
| A. vinelandii | P(3HB) | no data | Molasses | 60 | 1.4 | 0.12 | - (commercial data) |
| Various micro-organisms | P(3HB) | no data | Lignocellulose hydrolysates | 32-89 | 0.3-105 | 0.11-0.40 | - (commercial data) |
| E. coli harboring A. latus genes | P(3HB) | no data | Whey | 80.2 | 2.57 | 0.52 | - (commercial data) |
| R. eutropha ** | P(3HB) | no data | Plant oils | 62.5 | 0.96 | 0.72-0.76 | - (commercial data) |
| R. eutropha | P(3HB) | no data | Waste frying oil | 36.5 | 0.14 | 0.19-0.34 | - (commercial data) |
| P. cepacia | P(3HB) | no data | Glycerol | 31.4 | 0.6-1.5 | 0.062 | - (commercial data) |
| M. organophilum | P(3HB) | no data | Methanol | 52 | 1.8-2.0 | 0.19 | - (commercial data) |
| Methylotroph spp. | P(3HB) | no data | Methane | 51.0 | 0.031 | 0.55 | - (commercial data) |
Source:
Although the production cost data isn't present, our hope is that we can build a technical model that can compare all of the above on an equal basis (assuming a constant price for glucose rather than worrying about regional or local prices, etc.).
The ** signifies data from relatively large scale PHA producers, which is useful for us because we want to produce PHA at a large scale.
Our roadmap's primary focus is the production cost of PHA bioplastics. However, there are many variables and choices to take, so we need a technical model and some simplifying assumptions to explore the design tradespace.
As such, we need first need a governing equation for the production cost of PHA bioplastics that relates the production cost to commonly reported variables:

Where:
This equation was adapted from Yamane T. Cultivation engineering of microbial bioplastics production, FEMS Microbiology Reviews, Volume 9, Issue 2-4, December 1992, Pages 257–264, https://doi.org/10.1111/j.1574-6968.1992.tb05846.x
Comparing the list of variables here to the table given in the "Positioning of Company vs Competition", we see that many of the variables in this equation are explicitly stated, such as volumetric productivity and PHA content. The other variables can be determined given the information provided - for example, given the name of the substrate, one can find an expected cost, and given the substrate, organism, and product, one can determine the biological pathway that will determine the theoretical yield (kg PHA/kg carbon substrate).
This process will allow us to determine which parameters to focus on to yield a total production cost of PHA bioplastics of <=$1.5/kg.
First, just by exploring the equation above, we can determine normalized sensitivities to four of the most prominent variables. The design vector used to generate this chart was as follows:
Here are two examples of how to read the above:
These normalized sensitivities help us determine what to focus on as we map out a roadmap to achieving cost-competitive PHA bioplastics. In fact, we can already see that in order of the highest impact, the factors are:
(note that the percentage changes won't have a constant gradient, but these percentage changes give you an idea which are the bigger factors compared to the others)
This technical model shows us that the most important factor to focus on (to reduce PHA production cost) is theoretical PHA yield on carbon substrate.
However, it also shows that there isn't much of a difference in the impact of the different factors - the most important factor has a 3% "effect", but the least important factors still have a 1.7% "effect" on the PHA production cost.
This tells us we shouldn't single-mindedly focus on maximizing yield at the expense of the other variables, but we should start with a substrate with a reasonably high yield that's pretty cheap.
Here, we revisit our table from the previous section, which has 2 modifications made to it:
| Strain | PHA produced | Fermentation strategy | Substrate | PHA content (%) | Productivity (g- L-1-hr-1) | Yield ([g PHA]/[g carbon]) | Cost of carbon substrate ($/kg) | Production cost ($/kg) |
|---|---|---|---|---|---|---|---|---|
| P. cepacia | P(3HB) | no data | Glycerol | 31.4 | 0.6-1.5 | 0.062 | 0.04-0.11 | - (commercial data) |
| P. cepacia | P(3HB) | no data | Xylose | 60 | no data | 0.11 | 2.7-3.5 | - (commercial data) |
| Various micro-organisms | P(3HB) | no data | Lignocellulose hydrolysates | 32-89 | 0.3-105 | 0.11-0.40 | - | - (commercial data) |
| A. vinelandii | P(3HB) | no data | Molasses | 60 | 1.4 | 0.12 | 1 | - (commercial data) |
| M. organophilum | P(3HB) | no data | Methanol | 52 | 1.8-2.0 | 0.19 | 0.33-0.4 | - (commercial data) |
| R. eutropha | P(3HB) | no data | Waste frying oil | 36.5 | 0.14 | 0.19-0.34 | - | - (commercial data) |
| R. eutropha ** | P(3HB) | no data | Glucose | 73.8 | 2.42 | 0.32-0.48 | 0.39 | - (commercial data) |
| A. latus | P(3HB) | no data | Sucrose | 50 | 3.97 | 0.40 | 0.33 | - (commercial data) |
| E. coli harboring A. latus genes | P(3HB) | no data | Whey | 80.2 | 2.57 | 0.52 | 0.4 | - (commercial data) |
| Methylotroph spp. | P(3HB) | no data | Methane | 51.0 | 0.031 | 0.55 | 0.1 (US only) | - (commercial data) |
| R. eutropha ** | P(3HB) | no data | Plant oils | 62.5 | 0.96 | 0.72-0.76 | 0.85 (soybean oil) | - (commercial data) |
Source:
Here, we notice the two options with the best yield are R. eutropha from plant oils (0.72-0.76 g PHA/g Csubstrate) and Methylotroph spp. (0.55 g PHA/g Csubstrate) from methane respectively. However, the Methylotroph spp. option shows very low productivity [0.031 g PHA/(L-h)], while the R. eutropha from plant oils has decent (not extraordinary) values for content and productivity. This will be revisited later on.
Proceeding further, we can build a sample morphological matrix. Please note that the options in this morphological matrix are NOT exhaustive of all of the possibilities. The options are there only to give the reader an idea of what goes in each category.
In a general sense, most combinations are valid as long as the organism has a metabolic pathway for handling the substrate selected. Therefore, the only technical constraint to making choices in the matrix is the compatibility of the organism with the substrate - is the organism able to process the substrate into PHAs, or not?
As an example, here are the choices made for Danimer Scientific's Nodax, a family of PHAs that has been in use for several years.
Example application of the morphological matrix to Danimer Scientific's Nodax
Before we present the architectural decisions proposed for our company, we have to decide what order to make these decisions. To do this:
We will give each of our main 4 factors in the technical model an ID here:
The mapping above can be read as follows:
AD1, the choice of organism, impacts:
AD2, the choice of substrate, impacts:
AD3, the choice of PHA product, impacts:
AD4, fermentation strategy, impacts:
Now, for our selections: If we assume F1 is the most important factor, then this mapping shows that we should decide AD1 and AD3 first. For simplicity, AD3 is already assumed to be P(3HB), for the same reasons covered until now. With AD3 out of the picture, our decision sequence for a cost-competitive PHA production process is: AD1 > AD2 > AD4.
To decide AD1 (choice of organism), we want an organism that is able to more efficiently produce PHAs than other organisms for a given substrate. This means that the biochemical pathway used by the organism is as straightforward as possible with minimal detours leading to loss of valuable and costly substrate.
Through our research, we've determined that Rhodospirillum rubrum (R. rubrum) is a promising choice. This can be illustrated as follows:
Notice that the pathway used by R. rubrum, on the right, to convert butyric acid into PHB is a lot more straightforward than the pathway used by A. eutrophus, also known as R. eutropha, the same R. eutropha reportedly used by Danimer Scientific's Nodax in the example above.
This simplification of the pathway has a large effect on F1, the factor that we've shown has the largest effect on the cost of producing PHA.
| Carbon substrate | Assimilation pathway | NADPH regeneration | Theoretical yield of PHA on the carbon substrate |
|---|---|---|---|
| Butyric acid | A. eutrophus type | Isocitrate | 0.65 |
| Butyric acid | R. rubrum type | Not needed | 0.98 |
Source: Yamane T. Yield of poly-D(-)-3-hydroxybutyrate from various carbon sources: a theoretical study. Biotechnol Bioeng. 1993 Jan 5;41(1):165-70. doi: 10.1002/bit.260410122.
Because R. rubrum uses a simpler pathway, NADPH regeneration isn't needed which removes a potential "loss" of valuable carbon substrate, and the organism is instead able to produce more PHAs per kg of carbon substrate than A. eutrophus. We previously ballparked ~3% reduction in PHA production cost per 1% change in yield - here we have a ~50% increase in yield!. So, if the gradients were constant, the PHA production cost would reduce by -150%...although this is clearly impossible and the cost reduction will be lower than -150% due to diminishing returns, it gives the reader an idea of how much of a change is possible due to this change in yield.
To decide AD2 (choice of substrate), we'll first try what's already proven to work for R. eutropha (same as A. eutrophus) - plant oil (see table above). Although soybean oil is relatively expensive, we already know that R. eutropha is already able to deliver high yields from soybean oil, and according to L. Favaro et al (2018), PHA production from soybean oil is likely cost competitive.
Furthermore, there is probably enough supply of soybean oil for our company at the early stages: according to the USDA (https://www.ers.usda.gov/topics/crops/soybeans-oil-crops/), the United States is the world's leading soybean producer and the second-leading exporter. Soybeans comprise about 90 percent of U.S. oilseed production, while other oilseeds—including peanuts, sunflowerseed, canola, and flax—make up the remainder.
Lastly, we'll make AD4 (fermentation strategy) easy for now and just stick with fed-batch.
Therefore, our company's initial AD choices look like this:
Key publications:
Our first stop was [Choi, J., Lee, S. Factors affecting the economics of polyhydroxyalkanoate production by bacterial fermentation. Appl Microbiol Biotechnol 51, 13–21 (1999). https://doi.org/10.1007/s002530051357]. This paper covers a lot of ground directly relevant to our work:
Source: Choi, J., Lee, S. Factors affecting the economics of polyhydroxyalkanoate production by bacterial fermentation. Appl Microbiol Biotechnol 51, 13–21 (1999). https://doi.org/10.1007/s002530051357
This paper is an excellent introduction to our subject. However, although there is a lot of quantitative data, much of the discussion revolves around qualitative descriptions (such as "the carbon source cost contributes significantly to the overall production cost of PHA" without a numerical value to the significance.
Most importantly, this paper points out that the largest determinants of PHA production costs are mainly associated with the fermentation step, with only one factor related to downstream processing costs (recovery method employed). This tells us to focus on upstream processing (fermentation) costs.
Our search for a quantitative model to evaluate sensitivities led us to [Yamane T.Cultivation engineering of microbial bioplastics production, FEMS Microbiology Reviews, Volume 9, Issue 2-4, December 1992, Pages 257–264, https://doi.org/10.1111/j.1574-6968.1992.tb05846.x]. This paper covers:
This paper introduces a formula for the overall yield of PHB compared to the theoretical yield of PHB that wasn't fully derived. Therefore, we consulted the author's previous work, [Yamane T. Yield of poly-D(-)-3-hydroxybutyrate from various carbon sources: a theoretical study. Biotechnol Bioeng. 1993 Jan 5;41(1):165-70. doi: 10.1002/bit.260410122.], which provided a detailed definition of the formula introduced in the previous paper.
What's the focus of current research?
Oddly enough, although we have shown that improvements in yield (or a more efficient biochemical pathway) have a larger effect on the production cost of PHAs than the cost of the carbon substrate (in another window, see https://roadmaps.mit.edu/en/roadmaps/PHA_(polyhydroxyalkanoate)_bioplastics_manufacturing#Technical_Model), there appears to be a disproportionate focus on producing PHAs from inexpensive substrates rather than improving yield.
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Although this is admittedly a crude approach to seeing if the PHA community is more interested in substrates or yield by way of the number of mentions of each word in papers, we used this diagram to spark a conversation with people who have experience in this industry. The general response we've received is that there does seem to be a significant focus in the research community on simply whether PHAs can or can't be produced from unusual and inexpensive substrates (see a "PHA from wastewater" patent below) while not paying much attention to whether it is economically feasible to do so. In our opinion, we believe that an equal amount of attention should be focused on making PHA production economically feasible, and yield may be the best handle to do so.
Key patents:
Excerpt from US 10,745,722 B2, the patent about an engineered strain of E. coli that can be controlled to produce different PHA polymers. This is a good depiction of some of the biochemical pathways used to form PHAs. By varying the conditions at each of the steps, the balance between the three products at the bottom can be altered.
There are clearly many challenges ahead to producing PHAs at a commercial scale in an economically feasible manner, so there's a lot to do to stay ahead of the curve. However, as a startup company, we do not have a large team/large amount of resources to tackle multiple large opportunities at once.
We propose broad groupings to the R&T opportunities as follows:
A few R&T projects worth considering are shown in the Wheelwright and Clark model below. There is a limited amount because this is a small startup company operating in a fledgling market space. They are explained in the table below the graphic.

These projects are numbered and ordered in suggested order of priority. When setting the priority, our primary goals were to:
This way, each R&D project "forms a bridge to" the next, larger R&D project. We start with known methods and organisms and proceed onwards riskier methods and organisms.
The rationale for each project is explained in the table below as well. To be conservative, we assumed the PHA cost reductions delivered will tend towards the lower end of the ranges supplied below, and the durations of the projects all tend towards the upper ranges.
| Project number reference | R&T project description | Relevant Strategic Driver | Expected impact on FOM | Ballpark cost | Likelihood of success | Timeline | Priority rationale | Source |
|---|---|---|---|---|---|---|---|---|
| 1 (most pressing short-term need) | Altering PHA properties to target high margin applications (such as cosmetics) | Expanding the market/demand for PHAs | - | $200K (6 mos) | 100% | 3 to 6 mos | This is an immediate priority so that our company can target high margin but relatively small volume applications, like PHAs for cosmetics (see http://www.bio-on.it/what.php?lin=inglese), to recoup capital costs for the first plant. | Bonartsev, A. P., Bonartseva, G. A., Reshetov, I. V., Kirpichnikov, M. P., & Shaitan, K. V. (2019). Application of Polyhydroxyalkanoates in Medicine and the Biological Activity of Natural Poly(3-Hydroxybutyrate). Acta naturae, 11(2), 4–16. https://doi.org/10.32607/20758251-2019-11-2-4-16. |
| 2 | Integration of the aqueous two-phase extraction, a downstream process, into the overall process design | Reducing the cost per kg to produce PHA | 5-10% PHA production cost reduction | $200K (6 mos) | 70% (for 5% production cost reduction) | 3 to 6 mos | This is 2nd because it's a relatively easy win. This tech targets the downstream processing section of PHA production which is less connected and influential, but still an area that shouldn't be ignored. In the study referenced, the simulated cost of PHA production was reduced from $6.12/kg to $5.77/kg with this tech. | Yoong Kit, Leong & Show, Pau-Loke & Lan, John & Loh, Sandy Hwei-San & Lam, Hon & Ling, Tau. (2017). Economic and environmental analysis of PHAs production process. Clean Technologies and Environmental Policy. 19. 10.1007/s10098-017-1377-2. |
| 3 | Advanced modelling and simulation of the bioreactor. Includes building a model, installing sensors and collecting data. Results could be changing the bioreactor's operating parameters including strategic nutrient limitations to maximize PHA production. | Reducing the cost per kg to produce PHA | 15%-70% PHA production cost reduction | $1,200K (2 yrs) | 50% (for 20% production cost reduction) | 6 mos to 2 yrs | This might sound like it's too good to be true, but it really could be. The high end of the estimate, 70%, was seen with A. latus just by applying a nitrogen limitation. With R. rubrum, an increase in PHB cell content of 20% was observed when carbon and phosphorus limited versus carbon or carbon and nitrogen limited. Modelling and simulation is still a new field and is not in wide use yet. | Karmann, S., Panke, S., & Zinn, M. (2019). Fed-Batch Cultivations of Rhodospirillum rubrum Under Multiple Nutrient-Limited Growth Conditions on Syngas as a Novel Option to Produce Poly(3-Hydroxybutyrate) (PHB). Frontiers in bioengineering and biotechnology, 7, 59. https://doi.org/10.3389/fbioe.2019.00059 and Choi, J., Lee, S. Factors affecting the economics of polyhydroxyalkanoate production by bacterial fermentation. Appl Microbiol Biotechnol 51, 13–21 (1999). https://doi.org/10.1007/s002530051357 |
| 4 | Optimizing the process at a commercial scale. Includes designing equipment like the fermenter and the air blowers for minimum operating costs (stirrers in the fermenter, backpressure on the air blowers) | Reducing the cost per kg to produce PHA & enables commercial scale production | 15%-70% PHA production cost reduction (linked to #3) | $2,400K (3 yrs) | 80% (for 20% production cost reduction) | 1 to 3 yrs | This is really an extension of #3, but it specifically refers to optimizing for commercial scale production. This will enable our company to make the transition from small-scale to large-scale. Most tests are done today at a lab scale with expensive precursors and demand high amounts of oxygen. By using the processes and information gained from developing models, scale-up is derisked. | Favaro, L., Basaglia, M. and Casella, S. (2019), Improving polyhydroxyalkanoate production from inexpensive carbon sources by genetic approaches: a review. Biofuels, Bioprod. Bioref., 13: 208-227. https://doi.org/10.1002/bbb.1944 |
| 5 | Re-engineering pathways so R. rubrum can profitably make PHAs from syngas | Reducing the cost per kg to produce PHA | 50%-70% PHA production cost reduction (consider the price of plant oils vs the price of methane), and consider hydrogen produced as a byproduct at ~$2/kg to offset the cost of PHA production | $3,200K (4 yrs) | 20% (for 50% production cost reduction) | 3 to 5 yrs | As our company starts producing at a larger and larger scale, feedstock costs will not only become much higher due to the sheer volume and requirements on the supply chain but there could also be political and social backlash due to using a food source for something other than food. Therefore, it is important that we have a longer vision to transition away from using food (even plant oils) as a feedstock to a non-food and more sustainable feedstock. We selected R. rubrum because it carried an apparent advantage in a more efficient pathway to produce PHA than R. eutropha. R. rubrum is also very flexible at being able to handle a number of different substrates to make PHA, but it's not as efficient with those other substrates. By re-engineering the pathway to shortcut the potential loss points and provide a more direct path to producing PHA, we can take advantage of cheaper and more available feedstock. The technoeconomic assessment by Choi suggests that PHA production costs are only $1.65/kg, after factoring in the value of the hydrogen produced. | Guo-Qiang Chen, Xiao-Ran Jiang, Engineering microorganisms for improving polyhydroxyalkanoate biosynthesis, Current Opinion in Biotechnology, Volume 53,2018, Pages 20-25, ISSN 0958-1669, https://doi.org/10.1016/j.copbio.2017.10.008. and Ian Levett, Greg Birkett, Nick Davies, Aidan Bell, Alexandra Langford, Bronwyn Laycock, Paul Lant, Steven Pratt, Techno-economic assessment of poly-3-hydroxybutyrate (PHB) production from methane—The case for thermophilic bioprocessing, Journal of Environmental Chemical Engineering, Volume 4, Issue 4, Part A, 2016, Pages 3724-3733, ISSN 2213-3437, https://doi.org/10.1016/j.jece.2016.07.033. and Choi, D., Chipman, D.C., Bents, S.C. et al. A Techno-economic Analysis of Polyhydroxyalkanoate and Hydrogen Production from Syngas Fermentation of Gasified Biomass. Appl Biochem Biotechnol 160, 1032–1046 (2010). https://doi.org/10.1007/s12010-009-8560-9 |
| 6 | Engineering extremophiles (like Halomonas) to efficiently produce PHAs from methane, CO2 or syngas | Reducing the cost per kg to produce PHA | 20%-40% (??) PHA production cost reduction (certain steps in the PHA production process can be removed or consolidated - lysing, sterilization, etc.) | $4,000K (5 yrs) | 20% (for $20% production cost reduction) | 5+ yrs | The last stop of our company's journey, where it reaches maturity, is where we can use extremophiles to produce PHA instead of regular bacteria. By using extremophiles which are more used to extreme environments, the PHA production process conditions can be significantly altered as there is less fear of going beyond the organism's threshold as there is for regular bacteria. At this stage, the PHA production process will be consolidated and simplified as much as possible - we'll be using the cheapest feedstock possible (methane/CO2/etc.), with the simplest process possible (extremophiles). | Favaro, L., Basaglia, M. and Casella, S. (2019), Improving polyhydroxyalkanoate production from inexpensive carbon sources by genetic approaches: a review. Biofuels, Bioprod. Bioref., 13: 208-227. https://doi.org/10.1002/bbb.1944 and Mitra, R., Xu, T., Xiang, H. et al. Current developments on polyhydroxyalkanoates synthesis by using halophiles as a promising cell factory. Microb Cell Fact 19, 86 (2020). https://doi.org/10.1186/s12934-020-01342-z |
Before R&D, our company started with the following concept:
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If the R&D is successful, we envision ending with this concept:

The center idea of the business model is to reduce the cost to manufacture PHA so it can compete directly with the PP market (we established in earlier sections that PHA shares similar physical properties with PP). As a quick reminder, the current market price for PP is $1.3-$1.9/kg, so to start being able to compete at scale, we need to be able to sell PHA near this price. When taking into consideration the R&T projects listed above and discounting them by risk factor, we expect to reduce the price of PHA over 20 years so it is within a 30% margin to the projected cost of PP.
IdTechEx/McKinsey study on how much more consumers might pay for green products
This image depicts the relationship between the share of consumers willing to purchase a green product and the premium charged for that green product over an equivalent non-green product. We're using this general relationship (packaging is the closest analogy) to depict how we can access more consumers and a bigger share of the plastics market if we can sell PHAs (profitably) at a lower price.
Based on this data, we can assume that if PHA was $2.5/kg, 1.3x the price of PP (1.3x$1.9/kg upper bound for PP price = $2.5/kg), demand for PHA could be 5% of the total demand for PP. The chart below represents the expected total market demand in North America based on the expected price evolution of PHA over the next 20 years. The cost to produce each kg of PHA is expected to drop as a result of the company's planned R&T activities.
How market demand in NA is expected to change with PHA prices over the next 20 years
The figure below describes a financial model for a project to manufacture PHA at a commercial scale.

There are a few key elements depicted here:
If we're able to operate at 36% average margin for each kg of PHA over 20 years, and there are no tailwinds to help us like economies of scale or subsidies/regulatory incentives, we've estimated a break-even NPV of approximately $0.1 million over 20 years, but there are several areas of interest.
Major points of interest
Our target is to develop a cost-competitive process to manufacture PHAs that will allow us to replace oil-based plastics on a commercial scale by 2040.
Our short term goal is to achieve a target price of $2.5/kg of PHA, compared to the current $3-6/kg of PHA today. This is about 30% above the current price of PP ($1.3-$1.9/kg, the best target for PHA to substitute). At this price premium above PP we aim to claim 5% of the PP market by approximately 2025.
In order to achieve our goal of reducing the prince of PHA, we will immediately invest in R&D to reduce the production cost per kilogram of PHAs by studying strains of organisms that can make PHAs economically from inexpensive substrates and by studying and implementing the most efficient fermentation and downstream processes into the process design. Once this R&D has lowered the cost of PHA to ~$2.5/kg by 2025, we will build our first production plant capable of producing 12 ktons/year of PHA.
As our R&D continues, we expect the price of PHA to continue to drop and the demand to increase. As the demand increases, we will continue to build more production capacity as long as there is enough demand to make use of the additional production capacity.
Our long term goal is to disrupt oil-based plastics. By 2040, we aim to achieve a target price of $1.7/kg, comparable with the current price of PP ($1.3-1.9/kg) today. By 2040, we aim to hit breakeven while our company is producing 140 ktons/year of PHA, 15% of the expected PHA market at that time and 0.75% of the North American polypropylene market!

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