Physiological engineering project, supported by the RCGI, also benefits cattle feeding among livestock

Researchers in the Plant Biochemical Laboratory of the State University of Maringá (Bioplan-UEM) and the Ecological Physiology Laboratory of the University of São Paulo (LAFIECO-USP) were able to achieve up to a 120% saccharification of sugarcane bagasse over a period of 12 months. In the case of soy, there was a 36% increase in 90 days, while the saccharification of braquiaria grass rose 21% in 40 days.

This was due to spreading natural composts around the plants – one of which was based on Cinnamic Acid (MDCA); another, on pipecolinic acid (PIP); and a third that has daidzein (DZN). “We developed three different composts, each one having specific characteristics, which were applied individually to the sugarcane, soy, and brachiaria,” explains biologist Wanderley  Dantas do Santos, Bioplan-UEM Coordinator.

According Santos, MCDA, PIP, and DZN are modulators of lignin, a molecule that sustains the rigidity of the plant’s cell walls. “Generally speaking, the composts that we develop alter the metabolism of lignin. This facilitates access to the cell wall of the plant, which is where the cellulose is located. Thus it is possible to produce more sugar, more carbohydrates.”

The experiment, funded by the National Institute of Science and Technology (INCT) of Bioethanol, is reported in the article Natural Lignin modulators improve lignocellulose saccharification of field-grown sugarcane, soybean and brachiaria. The article, of which Souza is the lead author, was recently published in the journal Biomass and Bioenergy. The project is backed by the Research Centre for Greenhouse Gas Innovation (RCGI), which is sponsored by the São Paulo State Research Fund (FAPESP) in a partnership with Shell of Brazil.

 Increased production – In the case of sugarcane, this discovery could contribute to increasing the volume and lessening the cost of producing so-called second-generation ethanol, made from the plant’s biomass residue (bagasse). The big producer of this type of alcohol, corresponding to 1.5% of the nation’s production, is Raízen, a joint venture between Cosan and Shell of Brazil, located in outstate São Paulo. “Our plan is to generate a type of sugar cane that can be more easily saccharified, that is, to extract the sugars from the celluloses,” says Santos, who is a visiting professor at the RCGI.

According to botanist Marcos Buckeridge, Coordinator of LAFIECO-USP and of Bioethanol’s INCT, the industry currently has a high financial output for performing the so-called pre-treatment, when the lignin is removed in order to make the carbohydrates accessible to the enzymes that will then digest those polysaccharides and thus produce sugars that can be fermented to produce second-generation ethanol. “This has a 30% impact on production cost,” states Buckeridge, who is one of the world’s greatest specialists in second-generation alcohol and an RCGI researcher.

By applying the composts developed by the researchers, it would be possible to make better use of sugarcane biomass. “With lignin modulation, the bagasse becomes more easily digested by the enzymes. That is, it will be necessary to use less enzymes during the process. The enzymes are the most expensive part of the production of second-generation ethanol,” Buckeridge adds. Today, a good part of this bagasse is discarded by the industry. “The use of bagasse could increase ethanol production in Brazil by up to 40%.”

Feeding cattle – The researchers also tested the composts on the brachiaria used to feed cattle. “During digestion, the animal is able to extract more carbohydrates from this grass,” said Santos. “Since the herd will receive nutrition with a smaller quantity of the grass, it will be possible to have more cattle per square meter. For example, this would help avoid deforestation to produce animal protein.”

Soy with modulated lignin could also serve as feed for the herd. “Today, cattle are accustomed to being fed with corn and a protein complement. Soy could partially substitute this protein complement. By using composts, it becomes more palatable, in nutritional terms, and would leave the animal satisfied with a smaller portion of food,” says Santos.

Long-term research – Santos says that the article published in the journal Biomass and Bioenergy is the result of more than a decade of research. It all began during the post-doctoral stage of Plant Biochemicals and Ecophysiology which he wrote at USP, under Buckeridge’s supervision, between 2006 and 2009. Besides the two researchers, there were also undergraduate, Master’s, and PhD students of the UEM and USP, under the supervision of Santos and Buckeridge, who also worked on writing the article. “It is a team achievement,” states Santos.

In 2018, the three composts developed by the researchers were granted a patent. That brought about the creation of two startups headed by UEM students: Power Growth and Bio-solutions. Both have been mentioned in publications such as Catalisa, of the Brazilian Support Service for Micro and Small Businesses (SEBRAE) of the State of Paraná, and AWC, by the TIM service provider at the national level. “The idea is to develop a product based on one of these composts,” Santos explains.

But the research is still ongoing. With funding by the RCGI, the group is now developing a project for the purpose of testing the efficacy of the technology at Raízen, headquartered in Campinas. Furthermore, the researchers are developing a cocktail of Brazilian enzymes and fungi to be used in producing second-generation ethanol, so as to no longer depend on the European company that monopolizes the technology worldwide. “About 30% of the cost of second-generation ethanol is related to the purchase of these enzymes,” Buckeridge explains.

No side effects – According to Santos, none of the three modulators causes side effects for the plant. “We were able to arrive at a dosage that brings about saccharification without jeopardizing the growth of the plant,” states the researcher. Neither do the composts jeopardize other living beings. “These molecules contain only carbon, oxygen, and hydrogen. Therefore, they easily deteriorate in the environment. In this case, the plant itself destroys the molecules by converting them into water and carbon dioxide (CO₂). The composts do not leave residues that would later affect animals and human beings.”

The researchers also utilized so-called physiological engineering to induce the production of lignin. In a partnership with a large fertilizer industry in the State of Paraná, the group was able to show that soy plants treated with this type of compost present from 30% to 40% more lignin in their leaves, stems, pods, and grain. In this case, three types of composts were used to induce lignin. “For example, this protects the grain from mechanical damage that occurs during harvesting, transporting, and storage,” says Santos.

Furthermore, they also successfully obtained the use of physiological engineering to accelerate the production of saplings for urban tree planting, reforestation, and the recovery of degraded pastures. “The possibilities are countless and promising. Physiological engineering is a technology based on strategies used by plants themselves in nature. It opens up a whole new field of research and applications that, together with genetic improvement and genetic engineering, is only beginning to show its potential for contributing to the advancement of agriculture and agribusiness in Brazil,” Santos added.