Startup monitors proliferation of microorganisms that turn water bodies green

With FAPESP’s support, the startup plans to collect biomass from the cyanobacterial blooms that have turned the Pinheiros River green in São Paulo city and convert it to bioproducts.

By Roseli Andrion  |  FAPESP Innovative R&D – The Pinheiros River in São Paulo city (Brazil) has recently turned dark green as a result of cyanobacteria blooming driven by water pollution, a phenomenon seen in many parts of the world and set to become more frequent in the context of climate change.

Formerly called “blue-green algae”, cyanobacteria are photosynthetic prokaryotes that have existed on our planet since well before the first humans appeared, probably for about 3.5 billion years. “The problem now, however, is anthropic [human] activity, including the dumping of raw sewage and leaching of chemicals into rivers, reservoirs, lakes and lagoons,” said Kelly Fernandes, founding partner of a green tech startup called CyanoChem Soluções Ambientais. “The pollution supplies nutrients to the cyanobacteria, which grow much faster and spread throughout the environment.”

The firm’s researchers, who are based in Piracicaba (São Paulo state) and supported by FAPESP’s Innovative Research in Small Business Program (PIPE), are monitoring the proliferation of cyanobacteria and collecting biomass from these microorganisms in order to develop bioinputs and bioproducts for the chemical industry and agroindustrial sector, such as molecules, biofertilizer, and soil or plant biostimulants. 

Ernani Pinto and Marli Fiore, researchers affiliated with the University of São Paulo’s Center for Nuclear Energy in Agriculture (CENA-USP), are also collaborating on the project.

“We look for the causes of these blooms by monitoring their occurrence and doing laboratory analysis of material collected in the field in order to identify species and the compounds produced by these organisms,” Fernandes said.

Although cyanobacteria blooms occur in various parts of the world, higher temperatures and more intense solar radiation in tropical countries such as Brazil create ideal conditions for their rapid growth. Sunlight is essential for photosynthesis, and warm weather accelerates their metabolism.

“However, the key difference is the level of nutrients in the water, especially nitrogen and phosphorus, which contribute to the growth and multiplication of these organisms. The climate helps, but water pollution is a major influence,” Fernandes said.

Cyanobacteria cluster on the water column as they grow. Although they are microorganisms, their clustering forms a “green carpet” that is visible to the naked eye. “The blooms look like a thin film, but they can occupy 10 cm-50 cm of the water column, blocking out light and oxygen from the body of water. This can result in the death of fish, for example, and affects the aquatic ecosystem in many other ways,” she said.

“Investment by water treatment companies in solutions to combat cyanobacteria blooming is significant, but current practices are still insufficiently effective. The companies often use chemicals such as hydrogen peroxide, polyaluminum chloride and copper algaecides for water containing cyanobacterial cells. Use of these chemicals may not be the ideal solution and doesn’t tackle the root problem. It’s essential to seek and encourage the use of cleaner technologies to address this challenge.”

In light of these issues, CyanoChem decided to develop a device that could collect large amounts of this biomass, remove it from the water, and reuse it for other purposes. “We sought to develop a product that would be useful for society. We’re concerned about much more than water quality. People who live near water bodies with cyanobacteria blooms suffer from their bad smell, for example, and people who make a living from catching fish are directly affected by them,” Fernandes said.

The startup’s work involves a stage in the field to collect material and another in the laboratory to develop bioproducts from cyanobacteria. “Cyanobacterial biomass is very rich, and it’s possible to extract a wide array of products from it,” she said.

Collection of biomass is partly manual, but CyanoChem plans to mechanize and automate this process. “We care about protecting the environment, and we plan to convert the material we collect to biofertilizer, for example. The biomass has added value that can be leveraged,” she said.

Another concern is the possibility that the biomass may contain cyanotoxins, which can kill terrestrial and aquatic organisms. “Not all species produce toxins, but when they do, we can neutralize them in the lab and ensure the biomass is safe for use as raw material for biofertilizer since this material is rich in active ingredients. It’s a strategic product for us and our gateway to the market. We know there’s demand for it on the domestic market. It also offers the potential for extraction of other inputs, with a focus on high-value molecules,” she said.

Valuable pigment

Processing cyanobacterial biomass produces a valuable residue: a bright blue pigment called phycocyanin, which can be used by the textile industry to dye fabric and by visual artists. “Artists are increasingly conscious of pollution, and many don’t want to use chemicals to produce their work. We knew this pigment could be extracted from cyanobacterial biomass, but we were surprised to discover how much interest there is in it. We already have a number of partners who plan to start using it in their art, as well as a textile mill that’s interested in using this natural pigment as a fabric dye,” Fernandes said.

The technology used by CyanoChem has a competitive edge inasmuch as it converts cyanobacterial biomass into raw material for a range of commercial applications. “We help mitigate an environmental problem that affects society, our collection technology offers a sustainable solution with low environmental impact, and we convert a problem into resources with economic value. We can be useful to water supply and treatment companies, but our operations have much wider significance,” she said.

The technology is being developed by a highly qualified multidisciplinary team, and the startup expects to have it ready within two years.