The product developed in a partnership between Embrapa and Innova Agrotecnologia is made of three bacterial strains. Field tests have shown a 10% increase in grain yield when new bioinput was applied. Product can replace chemical fungicides, furthering environmental sustainability in the cultivation. After final tests, Combio should be the first multifunctional bioinput registered for Brazilian soybeans. The result of a partnership between Embrapa and the private company Innova Agrotecnologia, Combio is the first bioinput for Brazilian soybeans with two purposes: growth stimulation and protection against fungi. The product is a combination of three bacterial strains that have a role in biological nitrogen fixation and in promoting plant growth: BR 29 (Bradyrhizobium elkanii), BR 10788 (Bacillus subtilis) and BR 10141 (Paraburkholderia nodosa). "The difference in this inoculant is that we include bacteria that perform several stimulating mechanisms and that also protect the seeds in the stage they emerge from the soil, preventing attacks from opportunistic fungi", details researcher Jerri Zilli, from Embrapa Agrobiology, one of those responsible for the research. Field tests performed by Innova Agrotecnologia revealed a 10% increase in grain yield. Not even the strong drought that occurred in the 2020/2021 crop year prevented the satisfactory effect of the bioinput. In Paraná, while a crop without any inoculant had a yield of 61 bags per hectare, another with traditional co-inoculation yielded 63 bags and the area with Combio had a yield of 66 bags. "Our intention is not to confront the inoculants that are in the market. The goal is to encourage management that avoids chemical fungicides, which are considered aggressive to rhizobia bacteria", Zilli points out. The product stemmed from prospecting hundreds of bacteria with the aim of finding microorganisms that are antagonistic to fungi that interfere with the germination and emergence of soybean plantlets in the field. Nowadays, in order to ensure good plant population density, practically 100% of soybean croplands in Brazil receive seeds treated with chemical fungicides, which in most cases are harmful to Bradyrhizobium. “During the study, we observed that Bacillus subtilis and Paraburkholderia nodosa not only showed excellent antifungal potential, but also stimulated plants through different mechanisms, resulting in more uniform and vigorous plantlets", Zilli explains. Once the trait of promoting soybean plant growth was verified, the bacteria were combined with Bradyrhizobium, which is essential for the crop's nitrogen supply. After tests in greenhouses and in fields, it was found that the plants inoculated with Combio had a better development than with standard Bradyrhizobium inoculation and showed broad nodulation and health. The Embrapa researcher Luís Henrique Soares de Barros believes that Combio can advantageously replace the traditional soybean inoculant, which only contains the microorganism specifically aimed at biological nitrogen fixation. “In addition to the symbiotic microorganism, Combio has two other strains, which promote growth and provide the crop with more vigor through complementary biochemical action”, he reveals. Tests to validate the fungal antagonism effect for the purpose of registration as a biological fungicide are ongoing and comply with current legislation. The researchers expect that this advantage will be fully proven and that the product can soon be offered as the first multifunctional bioinput for soybeans. "We combined two roles in a single product, which provides greater practicality. With one less step in the field, the farmer has less work", Barros states. The product currently has a special temporary registration and is being offered as an inoculant that works both on biological nitrogen fixation and promoting the growth of soybean plants. in order to be traded as a biofungicide, it still has to meet some requirements of current Brazilian legislation. The expectation is that this new technology will be available in the next harvests. Combio's action The bioiput Combio is a liquid inoculant to be applied via seed treatment or in furrows. The strain BR 29 (Bradyrhizobium) works on nodule formation and on nitrogen fixation. The strains BR 10788 (Bacillus) and BR 10141 (Paraburkholderia) help to stimulate plant growth and protect seeds through their antagonistic capacity. The development of a multifunctional biological input for soybeans meets perspectives in the market, which has been increasingly looking for sustainable technological solutions to control pests and diseases and increase productivity. The advantage lies in reducing the use of nitrogen fertilizers and chemical products to control pests and diseases, which entails a more environmentally-friendly agriculture. For other commercial information about Combio, soybean growers can contact Innova Agrotecnologia. Prospecting for bacteria Research into the development of Combio started in 2020 and used the microorganism collection kept at the Johanna Döbereiner Biological Resources Center (CRB-JD), located at Embrapa Agrobiology in Seropédica, Rio de Janeiro. To formulate the product, over 700 bacteria were prospected within the CRB-JD collection. Initially, combinations of microorganisms were tested to combine biological nitrogen fixation with growth promotion. Based on an assessment of the strains, the researchers started to consider their potential in fighting fungi that are harmful to soybean crops - which would entail the development of an even more comprehensive and innovative product. With around 7,000 microorganisms, including bacteria and fungi, CRB-JD's collection was formed in the course of years of research making collections in nature, in different regions of the country. Each of the bacteria therein was studied and assessed regarding its potential for use as a biological input in Brazilian agriculture. This specific work started in the 1950s, when the researcher Johanna Döbereiner isolated the first nitrogen-fixing bacteria. Since then, the collection has multiplied and over 50 strains have already been authorized by the Brazilian Ministry of Agriculture and Livestock (Mapa) to be used in commercial inoculants. By 2012, only the phenotypic and morphological traits (appearance and shape) of CRB-JD's microorganisms had been known, and this limited the development of research. However, in recent years, the use of molecular tools has allowed a better understanding of their taxonomy (classification); moreover, a DNA bank has been structured and is available for researchers. Currently around 80% of the microorganisms in the collection have been characterized through DNA sequencing. This means that if anyone needs to conduct new studies for biotechnological work, they do not need to cultivate the bacteria; they can simpy use the stored DNA instead. In addition, the use of the DNA allows researchers to perform the genomic sequencing of bacteria and identify genes with agrobiotechnological potential. Pictures: Innova Agrotecnologia