Opuntia Cactus’ Greatest Ally

José Alves in the laboratory of OPUS Cactus © Anna Milovanovic

Using cacti for biofuel transformations is more challenging than one might imagine.

 “People need to understand that the cactus has a lot of potential,” José Alves tells me in his Groningen office at OPUS Cactus B.V. This tall, black-haired and bearded 40-year-old Portuguese agronomist has an encyclopedic knowledge of the plant and has spent his career persuading anyone who'll listen that if there's any plant that can save the planet, then it's the cactus.

Just an hour or so listening to his infectious enthusiasm has me considering its merits. Cacti can, he says, help the world achieve the United Nations Sustainable Development Goals (SDGs) related to environment, poverty and water scarcity, and he cites the Food and Agriculture Organization's findings that the cactus pear plant, among others, is one of the best solutions to combat hunger.

He's certain, for example, that cacti are good for the health, citing the benefits of the fruit and cladodes for Type II diabetes, and infusions from cactus flowers for prostate cancer among other medical and nutraceutical purposes.

To explain a simple remedy, he holds his hands in a Christian praying position in front of his chest, fingertips pointing upwards to form a triangle, describing how to slice and splay the interior of a flattened stem to access the cactus’ mucilage (thick sap). He says you place a bowl under the cladode to collect the dripping liquid, add brown sugar and “if you have a convulsive cough, you take one spoon of the liquid in the morning and it works very well.” His grandmother used to prepare this for his father.

Growing up in Southwest Portugal, wild cacti proliferated near his home, and he remembers summers with his parents, collecting the fruit and cladodes, eating them, as well as making juice, jellies, liquors, pickles, soups, and other natural products from them. “You can also eat the pads, the young plants of one year,” he says.

In Portugal, he was an agronomic engineer, producing cactus pear fruit on a five-hectare farm. He also founded the Portuguese Association of Cactus Pear (APROFIP), with other colleagues. Since coming to Groningen, he's shifted to producing the plants for biomass.

Among other species and varieties, he's concentrating on the Opuntia ficus-indica, which averages three-to-four meters in height and has what looks like clusters of tennis rackets for stems - the cladodes, or pads. The Netherlands-based OPUS Cactus, for which he now works, will be transforming the pads into biofuel, biogas, electricity, fodder for cattle as well as other organic products and sub-products - on its South African farm.

While some biofuel crops deplete existing rainforests to plant them, cacti are grown on arid and semi-arid land. “They're only going to be grown in a desert and areas or regions that don’t compete with other food crops,” he says. He describes the cactus as a pioneer plant, which OPUS then mixes with cover crops to make a sustainable farm, eventually requiring less intervention by the company on weed and pest management as well as fertilization and water management.

Explainer: Before COVID-19, OPUS Cactus’ two founders sought a solution for electricity problems in South Africa. They found a 1,000-hectare farm from a third-generation farmer, and after some initial challenges, were introduced to the company’s current main shareholder. As a result, OPUS Cactus was founded in 2022 and based its headquarters in Groningen in 2024. 

The company - focused on regenerative agriculture, energy, sustainable food production, and decarbonisation - is in its scale-up phase. Its current focus is biomass for biogas and silage (for cattle feed) through the use of Opuntia cactus as a sustainable feedstock in semi-arid regions, with part of its research and development exploring regenerative farming and biorefinery.

Information provided by OPUS Cactus Managing Director Joeri van den Bovenkamp - Hofman

José Alves alongside the cacti in the office’s front hallway © Anna Milovanovic

Walking through the entrance hallway, we see the plants up close. He points to a meaty, thick cladode and notes it has great mucilage content. He explains that this viscous fluid can be used in paint to extend its durability, and in water purification because it holds onto microbes, carbon, nitrates, and oils. He's convinced the cactus overall is helpful in numerous respects. For example, as a protective boundary during wildfires, and in absorbing more carbon dioxide than other kinds of plant (with implications for carbon sequestration).

In 2011, Alves authored Portugal’s first thesis on the characterization of wild cactus in the country. His study demonstrated the potential of Opuntia ficus-indica´s fruits, including as a source of natural antioxidants. It also undertook a technical and economic assessment of an Opuntia-ficus indica cactus orchard, which could be used as a guide for new cactus farmers.

He later began producing cacti and helped set up a farming cooperative to help producers pool their resources, especially around expensive machinery to clean the spiky fruits. They worked for four years, selling about 10-15% of their fruit nationally, but he then opted to start a consultancy company with a partner, which operated from 2012 until 2019.

The Opuntia ficus-indica propagates easily, he explains. And by placing a cladode one third buried in the soil, it will start to root and grow. However, if not properly managed for fruit and biomass production, it can become invasive and decrease native plants. “We need to understand that some species are invasive, others are not,” he says. “We work with non-invasive species; spineless cactus. It's easy to control.”

He spent four years trying to convince the Portuguese government to de-list certain cacti as invasive species there. His efforts included bringing government representatives to farms to check that cacti were not growing outside of farm boundaries - and the association’s efforts led to the permission of Opuntia ficus-indica cultivation. “The rest will likely be another battle,” he says with dread in his voice, and an eyeroll through his black-rimmed glasses.  

He then changes the subject, bringing me to the OPUS Cactus lab where research and development is expected to be fully operational come January 2025. Alves shows me a biodigester and explains how it will work at scale. They'll be testing 25 cacti varieties to identify the most productive, drought-resistant, pest-resistant varieties for biomass and biofuel, as well as good practices for micropropagation and extracting compounds. The company is also researching fertilizers and cover crops that can fix nitrogen into the soil, to help reduce the use of commercial fertilizers. 

A list of spineless cactus varieties © Anna Milovanovic

Alves is heading to Bloemfontein, South Africa, this month, to check up on the farm and its work on pest control varieties. He will also teach local farmers to prune and manage plants for biomass production. He's developing various standard operation procedures for pests, and the company is studying using drones with infrared cameras which help differentiate between the cactus and insect tissue, identifying problems that can't be seen with the naked eye.

As we leave the lab, he shows me each cactus lined up at the entrance to the building. A sign says do not touch, but we're both touching the smooth pads by the end of the conversation.

“We make a natural ecosystem,” he says, pointing to a Leucaena plant which he explains is planted as a cover crop between the rows of cacti that also helps fix nitrogen into the soil. “You are planting a high-density plant, but between the lines and in the out zone, near to the fence, we put other trees and other species. He adds that they can plant olive trees and acacia trees, plants to attract certain insects, and trees to control the wind and/or decrease erosion: all of them native species. 

One of his latest endeavors is forming an International Association of Cactus Pears to “reach a lot of countries to explain and to teach how to plant cacti, and [clarify] all its different uses." This ranges from pharmaceutical and nutraceutical uses to its application as feedstock and bioenergy. The association might also have an advocacy role to ensure legislation across the European Union and the rest of the World is consistent on de-listing non-invasive cacti. 

“I always wanted to be like an entrepreneur and the cactus was a really good opportunity to start my journey,” he says, adding, “I was always interested in helping people.” 

As we exchange phone numbers at the close of the interview, I send him my name and he responds with a simple emoji: the cactus.