Taming the dangerous – yet beautiful and profitable – castor bean plant

CorrespondentDecember 15, 2013 

  • Beautiful, dangerous ... useful

    The castor plant (Ricinus communis), known to humans since antiquity, is thought to have originated in Africa or India.

    It is prized for its striking bright green or purple foliage, vivid pink flowers, and for its variegated seeds, which are the source of castor oil.

    The castor plant grows worldwide, as a perennial in a tropical climate, and as an annual in most of the southern United States (hardy to Zone 9)

    It is used as an ornamental plant – seeds can be purchased online in the U.S.

    The plant grows in any kind of soil, from sand to clay, requires no fertilization and is drought tolerant.

    Because of its simple nutritional requirements, it also grows as a weed.

    The plant can grow 8 feet to 10 feet tall in a summer in North Carolina, and more than 15 feet in the tropics.

    But the seeds, leaves and stems of the plant are highly poisonous – caution is necessary if animals or children are present.

    Ingestion of as little as three or four seeds might kill an adult human.

    Thomas Burns Jr.

Novo Synthetix, a small biotechnology company in Research Triangle Park, is marshaling scientific resources statewide to create a nontoxic castor bean, which could provide a significant boost to North Carolina agriculture.

Novo Synthetix – the brainchild of biochemist Donald Walters and molecular biologist David McElroy – was started in 2012 with a $50,000 startup loan from the N.C. Biotechnology Center. Their idea was to use a novel genetic engineering technology to create a nontoxic castor bean, in an effort to revitalize castor as a cash crop in the United States.

The company won the Biotech Center’s Ag Biotech Entrepreneurial Showcase earlier this year, and last month, it was finalist in the Clean Tech Open Global Forum, in San Jose, Calif., which netted it a package that included cash and services worth up to $20,000.

The castor plant contains ricin, one of the most toxic substances known. The U.S. Centers for Disease Control and Prevention classifies it as a category B bioterrorism agent – one moderately easy to disseminate, which may result in moderate morbidity and low mortality rates. Ricin was used in the killing of Bulgarian dissident Georgi Markov in 1978, and was involved in an incident of bioterrorism as recently as this year. Their ricin content makes castor beans hazardous to harvest and process. The presence of ricin in castor processing waste is a health and a security concern.

A $400 million market

But because of the economic importance of its oil, castor is an important cash crop worldwide. “Castor produces a unique oil not found in any other plant on the planet,” Walters said. Castor oil is used in the manufacture of household products, lubricants, paints and dyes, plastics and pharmaceuticals. It commands nearly triple the price of other seed oils, such as soybean, canola or sunflower. The worldwide consumption of castor oil is upward of a billion pounds per year, and it is a $400 million market.

Castor production in the U.S. ceased in the 1970s. “Farmers would incur too much liability in producing a toxic bean,” Walters said. Since then, the U.S. has imported all of its castor oil, nearly $50 million worth per year, mostly from India. If Novo Synthetix can bring a ricin-free castor plant to market, “This could be the foundation for a resurgent, U.S.-based castor industry,” Walters said.

The company’s strategy is to integrate the powerful scientific resources present in the Triangle to create the new plant. They are employing an innovative technology supplied by Precision Biosciences, a Durham company, to genetically engineer the castor plant so it no longer produces Ricin.

Precision Biosciences’ system, called a Directed Nuclease Editor, allows modification of just about any gene in nearly any organism. It is not considered genetically modified organism technology because no foreign DNA is introduced into the host plant. This technology minimizes risk of transferring nondesirable traits into the host plant along with the trait of interest. Because of this, researchers can bypass regulations that apply to GMOs, producing a tremendous cost savings. “It costs upwards of $10 million to put a GMO on the market right now – we avoid all that by using this technology,” Walters said.

Development process

The experimental plants are being grown and tested in the laboratory of Dr. Linda Hanley-Bowdoin, a plant virologist at N.C. State. Walters expects a prototype plant within six months to one year.

Novo Synthetix will eventually produce two generations of products. The first will be ricin-free castor beans for use in agriculture. The second, more exciting possibility, is to use the Precision Biosciences technology to engineer the castor plant to produce so-called designer oils. “We would like to ask a chemist, ‘If you could have any oil you wanted, what would it be?’ ” said Walters.

For example, while castor oil can be used as a biofuel, it is only marginally suitable for that purpose. A simple, chemical modification to the oil would make it much more suitable. Such a modification would be expensive if it had to be done to tons of castor oil, but that cost could be eliminated if the processing happened in the plant itself.

A common criticism of biofuels is that land useful for food production is devoted to fuel production instead, and some biofuel sources – such as soybeans – are also food crops. This can lead to food shortages and higher food prices.

Castor is not a food crop and will grow on land that is unsuitable for food production, so it won’t compete with food production. It requires little fertilization and no irrigation, so it won’t consume resources that could be used for food production. A castor crop that produces an oil suitable as a biofuel could herald a new green technology in North Carolina. “We want to unleash it,” said Walters.

Novo Synthetix is working with Technology Crops International, which specializes in marketing specialty crops and oils, to market its products. TCI has its corporate headquarters in Winston-Salem, with offices in Canada and the United Kingdom. Its customer base is worldwide.

Novo Synthetix provides an excellent example of how integration of resources in the Triangle can turn scientific breakthroughs into marketable products. “It’s the place to be in ag biotech,” Walters said.

News & Observer is pleased to provide this opportunity to share information, experiences and observations about what's in the news. Some of the comments may be reprinted elsewhere in the site or in the newspaper. We encourage lively, open debate on the issues of the day, and ask that you refrain from profanity, hate speech, personal comments and remarks that are off point. Thank you for taking the time to offer your thoughts.

Commenting FAQs | Terms of Service