The bacteria that can produce endospores are primarily found within the Firmicutes phylum, specifically in the classes Bacilli and Clostridia. Some notable examples include:

Bacilli:

* Bacillus anthracis: Causes anthrax

* Bacillus cereus: Causes food poisoning

* Bacillus subtilis: Commonly found in soil and the gut

* Bacillus thuringiensis: Used as a biological insecticide

Clostridia:

* Clostridium botulinum: Produces the neurotoxin that causes botulism

* Clostridium difficile: Causes antibiotic-associated diarrhea

* Clostridium perfringens: Causes gas gangrene

* Clostridium tetani: Causes tetanus

While most endospore-forming bacteria are found in these two classes, there are a few exceptions. Some bacteria in the Actinobacteria phylum, such as Sporosarcina, can also produce endospores.

It's important to remember that not all members within these classes form endospores. Endospore formation is a specific adaptation to survive harsh environmental conditions, and it's not a universal characteristic of all bacteria within these groups.