A large group (genus) of gram-positive (see GRAM'S STAIN) rod-like BACTERIA found widely in the air and soil, commonly as spores. As well as infecting and spoiling food, some cause illness to humans, resulting in, for example, ANTHRAX, CONJUNCTIVITIS (see EYE, DISORDERS OF) and DYSENTERY. They are also the source of some antibiotics (See under MICROBIOLOGY.)