An article developed in partnership between researchers from the Graduate Program in Agricultural Microbiology (PPGMBA) at UFV and the Instituto Federal do Espírito Santo (Venda Nova dos Imigrantes campus) has mapped the presence of microorganisms in the soil and in coffee fruit. In the article “Microbiomes associated with Coffea arabica and Coffea canephora in four different floristic domains of Brazil” published in November in the scientific journal Scientific Reports, the group presents micro-organisms associated with soil and coffee fruit with the potential to help with soil and plant health, optimizing the pre- and post-harvest stages and making the process more environmentally and economically sustainable.

“Nowadays, a lot of chemical fertilizers are used on coffee plantations, and concern is growing about the environmental impacts that these fertilizers can have. Our bet is on using the micro-organisms that are already present in the crop to generate new products and, perhaps, increase the efficiency of these micro-organisms, pre-harvest, so that they can at least partially replace chemical fertilization,” explains Tomás Gomes Reis Veloso, PPGMBA post-doc and first author of the article. The samples used in the research were obtained from arabica and conilon coffee plantations in the Midwest, North, Northeast and Southeast regions of Brazil between 2020 and 2021.

Among the possibilities found by the researchers at this stage of the work are nitrogen-fixing bacteria, present in both arabica and conilon coffee soils, and arbuscular mycorrhizal fungi, which have the capacity to increase the absorption area of the roots in the soil and provide more nutrients, especially phosphorus, for the plant. “We have found these fungi in some regions that have drought problems, and somehow they are contributing to the development of the coffee tree. Now, once we know this potential, it’s easy to imagine that we need to look deeper into these microorganisms and understand the best way to use them.”

In the post-harvest stage, the researchers are betting that the micro-organisms can act to improve the taste of the coffee. Among the various forms of post-harvest processing of the fruit to generate the drink is the process of microbial fermentation, as happens with beer and wine. But in the case of coffee, the best alternatives among the various microorganisms capable of acting at this stage are still little explored. “The tendency is to use microorganisms that are already known and used in fermentation or even microbial cultures marketed for the production of bread, wine and beer. However, what we discovered is that in the coffee plantation itself there are already yeasts and bacteria that are native there and that would probably give a better flavor to the coffee drink,” says Tomás.

Next steps
In both cases, the researchers’ next step is to isolate these micro-organisms in laboratories and then understand the best way to exploit them, including creating commercial products that could even reduce the costs of traditional cultivation. “We’ve already isolated some of the microorganisms and we’re now going to focus on fermenting the fruit. In the case of the soil, we already have some isolated nitrogen-fixing bacteria, and the idea now is to carry out tests to see how viable they are for application in coffee plantations,” says the researcher.

At UFV, the work is coordinated by Professor Marliane de Cássia Soares da Silva, from the Laboratory of Mycorrhizal Associations (Lamic). The research exchange with the Coffee Design group of researchers, coordinated by Professor Lucas Louzada Pereira at IFES, has been going on for almost ten years. The coffee samples were collected during trips to coffee farms around Brazil by the IFES group and processed and analyzed by the UFV group. The authors of the article also include researcher José Maria Rodrigues da Luz and retired professor Maria Catarina Megumi Kasuya, both linked to Lamic, as well as Aldemar Polonini Moreli, a professor at IFES, and Taís Rizzo Moreira, from the Universidade Federal do Espírito Santo (UFES).