Immunostimulatory activity of inactivated environmental Bacillus isolates and their endospores.

ABSTRACT: The spore-forming capacity of Bacillus spp. enables environmental persistence and stable product formulations, yet the interactions of environmental Bacillus spores and vegetative cells with the human immune system are not fully understood. We investigated the immunostimulatory potential of seven environmental Bacillus isolates (B. subtilis, B. velezensis, B. licheniformis, B. pumilus) and optimized their inactivation methods to preserve surface integrity and immunostimulatory activity. Inactivation was evaluated using heat/UV-C and 10-100% formalin, followed by scanning electron microscopy and human reporter cell assays (THP1-Dual monocytes, HEK-Blue hTLR2/6 and hTLR4). Heat/UV-C treatment retained Bacillus morphology and enhanced immune activation compared to 10-100% formalin treatment.

SUBMITTER: Dekeukeleire M 

PROVIDER: S-EPMC12368082 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature