US agricultural bioscience company Yield10 Bioscience’s field testing of prototype lines of Camelina sativa to produce polyhydroxyalkanoates (PHA) bioplastics directly in seed has been a success, the company announced on 19 January.

Yield10 said the direct production of PHA in seed as a co-product with oil and protein meal could potentially enable production of PHA bioplastics on an agricultural scale at costs in line with commodity vegetable oils to drive large-scale adoption in the plastics markets. PHA bioplastics could ultimately be used to manufacture a wide range of fully biodegradable consumer products, it said.

The prototype plants tested in the trial were programmed with microbial genes based on a Yield10 patent to produce camelina seed containing high levels of PHA bioplastic suitable for field production.

Several camelina lines were grown in small plots at field test sites in the USA and Canada. Compared to control plants, Yield10 said the engineered PHA camelina lines had emerged and matured later but once established, had displayed good vigour, branching, flowering and seed set.

All engineered PHA camelina lines tested had produced PHA in the seed, Yield10 said. The levels of PHA produced in seed at the two different locations had been consistent and measured up to 6% PHA of mature seed weight depending on the plant line tested.

“Insights from our field tests as well as our expertise for increasing carbon flow in camelina from our GRAIN platform are expected to enable us to make further improvements to increase yields of PHA per acre,” said Kristi Snell, Yield10 Bioscience vice president of research and chief science officer.

“Although not essential for initial commercial launch, our long-term technology goal is to increase the PHA content of seed to about 20% of the mature seed weight and combine that with advanced higher yielding, herbicide tolerant varieties currently in development to drive production costs as low as possible.”

Based on these results, Yield10 had selected two PHA camelina lines for larger scale field testing in 2021, pending the issue of permits in the USA. In addition to generating more data, Yield10 plans to determine the suitability of the lines for initial commercial activities.

Each PHA application area had different price points and scale requirements, and would have different PHA content requirements for commercial launch, the company said.

Based on this, Yield10 believed that PHA content in the range of 5 to 20% of mature seed weight in camelina would address the range of target applications. Yield10 plans to extract the PHA bioplastic from the camelina seed for product prototyping, sampling and business development.

PHA are natural polymers, prevalent in nature and fully biodegradable in the environment. Currently produced by fermentation of engineered microbes, PHA polymers also have applications in water treatment where they act as a zero-waste solution to nitrate pollution and as animal feed ingredients.

Woburn-headquartered Yield10 develops crop systems and uses its ‘Trait Factory’ and its camelina ‘Fast Field Testing’ system to develop seed traits for the agriculture and food industries.

The company is pursuing a partnering approach with major agricultural companies to drive new traits into development for canola, soyabean, corn and other crops.

Yield10 is also developing improved camelina varieties as a platform crop for the production and commercialisation of nutritional oils and proteins. The company is also field-testing novel yield traits in canola.