Researcher from Brazil Develops Innovative Process to Produce Biological Pest Control Agent in HSBI Laboratory

Bielefeld (hsbi). Multiple harvests per year and an enormous diversity of crops – Brazil offers the best possible conditions for agriculture thanks to its favourable climate and its vast area. However, these conditions also benefit pests. “Their diversity, too, is extraordinary, which is a pity,” says Dr. Natasha Sant’Anna Iwanicki. Then she points to a petri dish containing a brownish substance and smiles: “But they have natural adversaries.” A powder? No, a dried fungus: Metarhizium anisopliae.

Since last August, Dr. Iwanicki has been conducting research at HSBI’s Faculty of Engineering and Mathematics as a visiting scholar in the working group “Fermentation and Formulation of Biologicals and Chemicals” headed by Prof. Dr. Patel, who is also Vice President for Research and Development in addition to his teaching and research activities. The agronomist, who holds a doctorate in Entomology, has profound knowledge of insects and also of the pests among them.

“Pests keep infesting arable crops, which leads to lower yields,” Dr. Iwanicki explains. The 34-year-old researcher from the Escola Superior de Agricultura Luiz de Queiroz (ESALQ) at the University of São Paulo has thus specialised in pest control – or, to be more precise: in biological pest control, which is becoming increasingly sought-after in Brazil. “The use of living micro-organisms such as fungi or bacteria is much safer for the environment, for producers and for consumers than the use of chemical pesticides,” Dr. Iwanicki says. After all, these micro-organisms are naturally present in soil, water and air, and thus they show good biodegradability. In addition, they naturally prefer pests as hosts whom they infect and, in the end, eliminate.

Researchers in São Paulo and Bielefeld mull over how to bring the fungi onto the field

There is thus no doubt about the potential of micro-organisms like Metarhizium anisopliaea and Beauveria bassiana to act as insecticides. “The only challenge is to find out how we can bring the fungus on the field,” says Dr. Iwanicki. And Professor Patel is the right person to ask: He has been conducting research on biological pest control for many years and is an expert for formulation materials and technologies, i.e., the transfer of agents to a form in which it can be applied technically. “This aspect is often the real challenge in research,” Professor Patel says. He is happy about Dr. Iwanicki bringing her own expertise to his working group: “We benefit a lot from the exchange with the researchers from São Paulo, as the working group there is among the best worldwide. This internationalisation enriches our research with other approaches and mindsets.”

Only a short while ago, members of both working groups published their joint research results in an article. Professor Patel, too, has visited ESALQ and Dr. Natasha Iwanicki is the second researcher from the Brazilian working group to come to HSBI for a year. “It’s a great experience to work in such a well-equipped laboratory, and even more so to work with Professor Patel’s highly qualified and internationally renowned research team!”

Liquid fermentation makes fungi manufacturable in large quantities and good quality

She also brought her project member Luiz Felipe Zumpano with her for six months. In addition to the good research conditions at HSBI, another aspect was a dream come true for the bachelor’s student: “My great-grandfather is from Germany and I really wanted to study here for a while.” His aspirations were enabled by a Brazilian scholarship and facilitated by HSBI’s Welcome Center. “The team around Maximilian Köster has provided great support with all formalities, starting with visas and ending with accommodation,” Dr. Iwanicki emphasises. Having studied in Norway and obtained a dual doctorate from the Universities of Copenhagen and São Paulo, she already has extensive international experience. 

This made it easier for Dr. Iwanicki and Luiz Zumpano to start working right after they arrived. “The fungus-based pest control agents that are currently available on the market are produced using solid-phase fermentation,” Dr. Iwanicki explains. “That means that the fungi are cultivated on a crop substrate, which brings numerous restrictions with it, for example, a lower growth rate, an uneven distribution of nutrients and difficult process management.” In the end, the biological pest control’s quality suffers. The researcher opens an incubator, takes out a conical flask and swirls it from one side to the other with a scrutinising look. “We, in contrast, rely on liquid fermentation. This is the method of producing the fungi in a nutrient solution. In this method, not only do they produce various infectious cells for pest control, the industry prefers this method, too, as it offers better opportunities for automation and scaling.”

Drying the biological pest control agent at extremely high temperatures

For a product that can be applied in practice, however, the fungus is needed in a dried form again. “The dried fungus lasts longer and can be stored better. The farmers then dissolve it in water as needed and apply it on the field.” However, Metarhizium anisopliae is very delicate. “It is very sensitive when it comes to the necessary drying process,” Dr. Iwanicki reveals. Her innovative approach is thus to precondition the fungus. “During the cultivation phase, we change various parameters such as temperature or osmotic concentration and use a protective formulation, a kind of protective shell so to say.” The goal is for the produced fungal cells to develop the required properties: “We want them to survive the drying process.” A visit to HSBI’s machine shop demonstrates that the requirements are high. In this hall, the working group’s spray dryer is located. Dr. Iwanicki and Luiz Zumpano put on their protective glasses and insert the liquid fungal culture. “Now it’s going to get really hot,” says Zumpano. Industrial spray dryers reach temperatures up to a high three-digit degrees Celsius range. “It must be done quickly,” Dr. Iwanicki says and smiles. And then a fine powder is already trickling into the collection vessel.

To identify the optimal parameters for preconditioning the researchers had to conduct countless experiments. “We were in the laboratory all day every day,” Luiz Zumpano says. He looks out of the window to the Teutoburg Forest and laughs. “But I did manage to go into the forest, too. It’s really beautiful!” In the end, the fungal cells also had the required properties: the powder is alive. And Dr. Natasha Iwanicki is happy about it: “Thanks to preconditioning, we can significantly improve the fungal cells’ viability after drying them at high temperatures.”

Her next test object is Pseudomonas protegens. The bacterium is also an insecticidal micro-organism and Dr. Iwanicki wants to try the preconditioning process on it, too. “Our experiments are still ongoing.” She has time to complete them until the summer. Only then will she return to Brazil. Luiz Zumpano already has to say goodbye now. “I will miss the working group members in particular,” he says, sounding a little melancholy. But what is he looking forward to at home? He does not hesitate to answer for a second: “Brazilian cuisine!” – luckily, his research will contribute to it continuing to be so varied. (uh)

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