How are microbial toxins different from plant and animal toxins?

Biotoxins are categorized by their source into microbial toxins, phytotoxins (plants), and zootoxins (animals). While all are biologically derived, they differ significantly in their distribution, chemical composition, and function.1

Distribution and Function

Microbial toxins are produced by microscopic organisms like bacteria and algae, which are ubiquitous in their distribution. In contrast, poisonous plants and animals are most abundant in tropical and warm-temperate regions. Evolutionarily, animal toxins often serve as mechanisms for food procurement or defense, whereas microbial toxins may function as chemical warfare to regulate populations or exclude competitors.12

Chemical and Structural Differences

• Microbial Toxins: Bacterial toxins are classified as exotoxins (typically proteins) or endotoxins (complexes of proteins, polysaccharides, and lipids). Exotoxins are generally more toxic and heat-labile than endotoxins.3
• Plant Toxins: Phytotoxins comprise a diverse range of chemical substances, including alkaloids, glycosides, resins, and toxalbumins (highly toxic proteins).4
• Animal Toxins: Zootoxins are typically transferred via bites or stings.12