MALAGA — Scientists from the Department of Microbiology of the University of Malaga and the Institute of Subtropical and Mediterranean Horticulture 'La Mayora' discovered a mechanism that allows the bacterium Bacillus cereus to protect itself against antibiotics and adverse conditions. This study, which identifies the molecular system enabling the assembly of the protective scaffold in Bacillus cereus biofilms, was published in the journal Science Advances on June 23, 2026.

Bacillus cereus is responsible for food poisoning and human infections. The bacteria form highly organized communities called biofilms, which act as a protective shield. Within these biofilms, the bacteria aggregate and generate a matrix that isolates them from their environment. Professor Diego Romero, one of the researchers, said, "This type of structure is behind many persistent infections and food contamination problems that are difficult to eliminate."

The protection mechanism in Bacillus cereus is based on three key proteins: TasA, CalY, and CapP. These proteins coordinate the formation of filamentous structures on the exterior of the bacteria. The CapP protein controls the timing and method of assembly for these filamentous structures. Romero added, "Without this control, the bacteria would not be able to form biofilms properly, which demonstrates their essential role in the survival of the microorganism."

If the primary protection system fails, Bacillus cereus activates alternative mechanisms, such as producing extracellular DNA or changing its mobility. The study was carried out by the 'BacBio' group of the University of Malaga and the IHSM. The University of Bordeaux and the CNRS also collaborated on the research. The study resulted from the doctoral thesis of researcher Ana Álvarez-Mena, who conducted research stays in France focusing on structural analysis techniques at an atomic scale. The paper is titled 'Matrix plasticity and the molecular basis of extracellular filament assembly in Bacillus cereus'.