The National Polytechnic Institute (IPN) is promoting one of the most promising biotechnological approaches for Mexico’s energy transition. A system capable of transforming agricultural waste and food scraps into bioethanol, biodegradable bioplastics, and advanced biocarbons.

This project, led by researchers from the National School of Biological Sciences (ENCB, by their acronyms in Spanish), Jorge Alberto Mendoza Pérez and Elier Ekberg Neri Torres, was selected to receive funding in the energy category during the Third Meeting of Polytechnic Research Networks to develop a one-pot bioreactor. This support marks the beginning of a key phase to integrate, strengthen, and scale up the technology.

TONS OF WASTE ARE WASTED EACH YEAR

According to the Agricultural Waste Management Plan of the Ministry of Agriculture and Rural Development (Sagarpa, 2015), Mexico generated more than 80 million tons of agricultural waste per year, and although there is no more recent figure available, globally, agro-industrial waste accounts for a growing fraction of the 11.2 billion tons of solid waste generated each year.

Most of this biomass—straw, stalks, crop residues, husks, and leaves—ends up being burned or discarded, contributing to polluting emissions and the loss of valuable resources.

“That enormous volume of waste can be transformed into something useful; it doesn’t have to be left lying around or become pollution”, explained Dr. Jorge Alberto.

The centerpiece of the project is a bioreactor designed according to the principles of green chemistry and process efficiency. It is a technological innovation that integrates the metabolism of a consortium of microorganisms to produce fuel, bioplastics, and other byproducts in a single unit: a true one-pot system.

“Before, we needed a reactor for each transformation. Green chemistry taught us that it was possible to combine processes and have a single bioreactor do all the work”, Mendoza Pérez explained in an interview with the Conversus News Agency (AIC).

Inside the reactor, thousands of yeasts, bacteria, and other microorganisms work as a consortium capable of transforming the sugars present in the waste into bioethanol, a renewable biofuel essential for replacing harmful additives in gasoline.

The same microbial consortium can also accumulate polyhydroxyalkanoates (PHAs), polymers that can be used to create 100 percent biodegradable bioplastics and represent a viable alternative to petroleum-based products. In addition, the process generates biochar and nanocarbon through pyrolysis, materials that are valuable for regenerative agriculture and industrial applications.

The reactor’s efficiency has already been demonstrated: the polytechnic team has tested the methodology with a wide variety of waste materials, including sargassum, water lilies, bagasse, fruits, and peels. A study published in 2021 in Industrial Crops and Products, of which Dr. Mendoza is a co-author, demonstrated the ability to convert agave bagasse into fermentable sugars and methane, validating the technology’s potential.

HOW DOES AN ALL-IN-ONE BIOREACTOR WORK?

The operating process of this bioreactor consists of three parts. Fermentation, where pulverized waste enters the reactor. Yeasts break down polysaccharides, ferment the sugars, and generate bioethanol.

Then, as sugar levels drop and conditions change, the yeast enters a state of metabolic stress and begins producing these biopolymers within its cells. And this is where researchers can harvest the PHAs (biopolymers).

Finally, the process reaches pyrolysis, a thermochemical process in which organic materials are broken down by extreme heat in the absence of oxygen; this involves heating the leftover biomass in the absence of oxygen to produce biochar and nanocarbon.

As Mendoza describes it, “this integrated sequence allows us to recover value from even from the very last remnants of the process”. The project advances not only in terms of industrial processes but also in the molecular understanding of the microbial consortium that makes the reactor possible.

At ENCB, professor Elier Ekberg Neri Torres has characterized the enzymatic machinery of bacteria and yeasts to identify which species respond best to different agricultural wastes.

“We needed to know which yeasts have the right enzymatic toolkit to degrade these polysaccharides; using simulations and In silico models, we can predict which ones are the most efficient at generating both alcohol and PHAs”, explained Neri Torres.

A review published in 2024 in the journal Energies—of which Neri Torres is a co-author—details why yeasts are excellent biofuel producers: they grow quickly, tolerate harsh conditions, and utilize a wide variety of substrates.

His molecular research led to the discovery of a highly resilient yeast strain capable of fermenting various types of waste—such as fruit, sargassum, water lily, and agricultural biomass—while simultaneously accumulating PHAs. “Finding a yeast strain that can produce alcohol and, at the same time, accumulate PHAs opened the door to a truly integrated process”, he added. This breakthrough confirmed the viability of the one-pot system and paved the way for what the team already envisions as a Polytechnic-developed biorefinery.

COLLABORATION BRIDGING SCIENCE, ENGINEERING, AND MOLECULAR MODELING

The project is a joint effort of the IPN’s Polytechnic Research and Graduate Networks, a collaborative model where specialists from different fields work to solve real-world problems and put “Technology in the Service of the Nation”. The ENCB is involved in this project, as are researchers from other IPN campuses, such as the Interdisciplinary Professional Unit in Engineering and Advanced Technologies (UPIITA), in the instrumentation, monitoring, and design of solar dryers; from the Center for Research in Applied Science and Advanced Technology (CICATA), Legaria Unit, with membrane separation engineering and process design; and from the Mexican Center for Cleaner Production (CMP+L), with molecular analysis and recovery strategies.

“Combining fermentation, molecular dynamics, selective membranes, and pyrolysis into a single process is no small feat; it requires the combined strength of the IPN”, noted Neri Torres.

A BOOST THAT OPENS THE DOOR TO SCALABILITY, BIOREFINERIES, AND COLLABORATION WITH PRODUCERS

The project secured 1.5 million pesos in funding, which will be allocated to new bioreactors, separation membranes, solar dryers, and specialized software.

This funding will enable the next phase: partnering with agricultural producers in the State of Mexico to collect, dry, and characterize their own biomass.

“If we manage to scale up, we can create jobs, train producers, and strengthen local economies with a circular economy model”, noted Mendoza, a graduate of the Polytechnic Institute.

In the medium term, the team aims to establish a biorefinery capable of processing various types of waste and generating multiple valuable products. “Mexico needs this, and the IPN can build it”, stated Neri Torres.

MEXICAN SCIENCE THAT TRANSFORMS THE FUTURE

The IPN’s proposal demonstrates that Mexico has the capacity to transform waste that is normally discarded or incinerated into renewable energy, sustainable materials, and high-value industrial solutions.

In a context where the country is seeking clean alternatives and circular production models, this technology offers a concrete path toward a fairer and more sustainable energy transition, in line with commitments made at the Conference of the Parties to the United Nations Framework Convention on Climate Change (COP27).

It is proof that Mexican science not only explains the present but is also rewriting the future based on what is no longer useful.