Leaf-Based Process Produces Low-Cost Enzymes

Tobacco plants (Beeki, Pixabay)

22 Apr. 2019. A University of Pennsylvania lab is developing a process for producing enzymes, chemicals from organisms that act as catalysts, in green leafy plants at low cost. Researchers led by UPenn dental school professor Henry Daniell describe the process in 2 papers published earlier this month in the journal Plant Biotechnology Journal, a publication edited by Daniell.

Daniell is also scientific founder of the start-up company PhylloZyme, begun in November 2018, which licenses and commercializes his lab’s technology.

Enzymes are produced today either naturally in seeds or by fermentation, using microbes like fungi or bacteria, to produce the chemicals. Daniell says the fermentation process is slow and expensive, contributing to the high cost of pharmaceuticals. Fermented enzymes are produced as liquids that need stabilizers and cold storage to maintain freshness over extended periods. In addition, fermentation processes release carbon dioxide, a greenhouse gas, into the atmosphere contributing to climate change.

Daniell and colleagues devised a process that produces enzymes in chloroplasts, the components in plant cells that capture energy from sun, and with carbon dioxide perform photosynthesis. Their process harnesses chloroplasts in leafy plants like tobacco or lettuce, turning their leaves into enzyme-producing factories. The leaves then are dried and crushed into a powder that can be stored at ambient temperatures and remains stable for months and even years. And because the plant leaves absorb rather than emit carbon dioxide, the process is also more climate-friendly than traditional enzyme production methods.

In the first paper, the researchers used the Daniell process to produce pectinases, enzymes that break down pectin, a natural substance in many fruits and a common component in cotton fibers. Pectinases are used in cotton production to remove pectin from fibers, enabling the fibers to absorb water. In their study, the UPenn team produced pectinases with their process, which they turned into a powder that remains stable and active for 16 months, and when applied to commercial processes, results in cotton fibers that easily met industry standards. Tests with orange juice, show the leaf-produced pectinases clarifies orange juice — removes excess pulp and other suspended particles — as well as fermented enzymes.

In the second study, Daniell’s lab produced 5 enzymes from their leaf-production process, which they tested against 15 commercial enzyme products used in detergents and the textile industry. The results show the leaf-produced enzymes removed stains like mustard oil and chocolate as well as today’s commercial detergent enzymes. The Daniell-process enzymes also removed dyes from denim as efficiently as commercial enzymes, and smoothed knitted fabrics, removing excess horizontal fiber strands from the fabric, also much like commercial enzymes. And as in the first paper, the leaf-produced enzymes remained stable and active in powder form for 16 months.

“The current technology to produce enzymes hasn’t advanced for decades,” says Daniell in a UPenn statement. “If we are selling these enzymes to something like a juice company,” he adds, “it would be a huge advantage to have a safe, inexpensive, and shelf-stable product they can turn to as an alternative to currently available enzymes.”

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