Gram-positive bacteria, like Proteobacteria, are a very diverse phylum of bacteria. They include photosynthetic and chemoheterotrophic bacteria, and some, but not all, form spores. DNA sequencing has shown some gram-negative bacteria to be closely related to actual gram-positive bacteria so species like mycoplasmas, which are tiny 1 nanometer organisms that lack cell walls, are included in the phylum. Mycoplasmas are the smallest living things on Earth.
Anthrax is a gram-positive aerobic rod chemoheterotroph who is immune to phagocytosis. Click on any of the pictures for more information.
Actinomycetes are prokaryotic bacteria who ressemble fungi, yet are bacteria because they are not eukaryotic.