Microbial toxinMicrobial toxins are toxins produced by micro-organisms, including bacteria, fungi, protozoa, dinoflagellates, and viruses. Many microbial toxins promote infection and disease by directly damaging host tissues and by disabling the immune system. Endotoxins most commonly refer to the lipopolysaccharide (LPS) or lipooligosaccharide (LOS) that are in the outer plasma membrane of Gram-negative bacteria. The botulinum toxin, which is primarily produced by Clostridium botulinum and less frequently by other Clostridium species, is the most toxic substance known in the world.
ToxicityToxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell (cytotoxicity) or an organ such as the liver (hepatotoxicity). By extension, the word may be metaphorically used to describe toxic effects on larger and more complex groups, such as the family unit or society at large.
Diphtheria toxinDiphtheria toxin is an exotoxin secreted mainly by Corynebacterium diphtheriae but also by Corynebacterium ulcerans and Corynebacterium pseudotuberculosis. the pathogenic bacterium that causes diphtheria. The toxin gene is encoded by a prophage called corynephage β. The toxin causes the disease in humans by gaining entry into the cell cytoplasm and inhibiting protein synthesis. Diphtheria toxin is a single polypeptide chain of 535 amino acids consisting of two subunits linked by disulfide bridges, known as an A-B toxin.
Aquatic toxicologyAquatic toxicology is the study of the effects of manufactured chemicals and other anthropogenic and natural materials and activities on s at various levels of organization, from subcellular through individual organisms to communities and ecosystems. Aquatic toxicology is a multidisciplinary field which integrates toxicology, aquatic ecology and aquatic chemistry. This field of study includes freshwater, marine water and sediment environments.
