The laboratory of the University of Malaga ‘Bacbio’ has verified that the cells of Bacillus subtilis, who have been deprived of a protein of amyloid nature (TasA), show a whole series of abnormalities and cytological dysfunctions that lead to their premature death. A finding that allows progress in understanding the role of these proteins, widely distributed in the microbial world, and help improve biological control methods in sustainable agriculture. The research has recently been published in the scientific journal Nature Communications.

Specifically, the UMA scientific team has shown how this amyloid protein, TasA, necessary for the assembly of bacterial communities called ‘biofilms’, it also prevents the death of the bacterial cell, but preserving the integrity of the cell membrane. “That is to say, we have seen in these proteins a complementary role to the merely structural one”, explains the main author of this work, the researcher Diego Romero, who also belongs to the Institute of Subtropical and Mediterranean Horticulture “La Mayora” (IHSM), mixed center of the Higher Council for Scientific Research (CSIC) and the UMA.

According to the expert, this double function is reflected in the adaptation of the bacteria to the surface of plants, where it contributes to combat the attack of pathogens and improve your well-being. “Our objective is to promote its use in sustainable models of crop production and protection,” says the professor in the Department of Microbiology at the UMA.

Thus, in this study, the Bacillus subtilis bacterium has been studied with emphasis on two aspects: the study of its molecular bases, which lead to the formation of bacterial communities known as ‘biofilms’; and how these biofilms contribute to the beneficial activity of Bacillus as biocontrol agents in models of sustainable agriculture.

Amyloids: double function

Amyloids are proteins known primarily for their association with degenerative diseases in humans. In fact, they give name to ‘amyloidosis’, a condition produced by the accumulation of amyloids in the organs or tissues. However, according to this research, amyloid proteins, including TasA, have the ability to adopt a fold with very different purposes in nature, which is why they are called functional amyloids.

“The fact that these proteins are widely distributed in the microbial world, opens the possibility that in other bacterial species they are playing a role in stabilizing cellular integrity, or, at least, a different and complementary role to that initially observed in each one of those systems ”, clarifies Romero.

The expert affirms that the importance of these results is twofold. From an agrobiotechnological point of view, it allows us to better understand how beneficial bacteria behave, and therefore, its use can be improved and reinforced within sustainable production and protection programs. On the other hand, from the microbial, where amyloid proteins are widely distributed, a new target has been given to attack if it wants to harm a pathogenic microbe.

This study has been carried out thanks to funding from the ‘European Research Council’ (ERC-StG program), which promotes top-quality research projects, and from the Ministry of Economy and Competitiveness.

The ‘Bacbio’ Laboratory, located in the Bioinnovation building of the University of Malaga, has been working since 2013 to study the physiology of bacteria, as well as their interaction with the environment. Plants are other of its priority lines of study, specifically cucurbits, among which are melon and cucumber.