S, 2004). Their anatomy features Gram-positive, nonsporulating, polyploidic cocci, lacking flagella and motility and resistance to hydrogen peroxide and other agents that damage DNA because of a highly efficient DNA repair system. Although they are considered Gram-positive, they may be an intermediate between gram-positive and gram-negative bacteria and form a distinct bacterial lineage of extremophiles; the Firmicutes phylum has a diversity of microbes associated with the human gastrointestinal tract, especially with fatty acids absorption which makes it connected with obesity when a change in the microbiome occurs, and dominate the bowel environment being linked to human bowel inflammatory diseases. Are also found in at least 60 mammalian species. The Proteobacteria, also known as purple nonsulfur bacteria , is divided in beta, gamma and epsilon Proteobacteria and its organisms are Gram-positive and can grow in an anaerobic environment, using oxyanions of arsenic and as terminal electron acceptors. Also, they can grow on aromatic compounds are Lithoautotrophy, chemoheterotrophically or photoheterotrophically . Shows high-level resistance to tellurite, selenite, and at other rare-earth oxides (Moore, M. D., and Kaplan,
S, 2004). Their anatomy features Gram-positive, nonsporulating, polyploidic cocci, lacking flagella and motility and resistance to hydrogen peroxide and other agents that damage DNA because of a highly efficient DNA repair system. Although they are considered Gram-positive, they may be an intermediate between gram-positive and gram-negative bacteria and form a distinct bacterial lineage of extremophiles; the Firmicutes phylum has a diversity of microbes associated with the human gastrointestinal tract, especially with fatty acids absorption which makes it connected with obesity when a change in the microbiome occurs, and dominate the bowel environment being linked to human bowel inflammatory diseases. Are also found in at least 60 mammalian species. The Proteobacteria, also known as purple nonsulfur bacteria , is divided in beta, gamma and epsilon Proteobacteria and its organisms are Gram-positive and can grow in an anaerobic environment, using oxyanions of arsenic and as terminal electron acceptors. Also, they can grow on aromatic compounds are Lithoautotrophy, chemoheterotrophically or photoheterotrophically . Shows high-level resistance to tellurite, selenite, and at other rare-earth oxides (Moore, M. D., and Kaplan,