Although inorganic phosphate is primarily used in the Pho regulon system, there are several species of bacteria that can utilize varying forms of phosphate. One example is seen in E. coli which can use both inorganic and organic phosphate, as well as naturally occurring or synthetic phosphates (Phn). Several enzymes breakdown the compounds of the alternative phosphates, allowing the organism to use the phosphate via the C-P lyase pathway. Other species of bacteria like Pseudomonas aeruginosa and Salmonella typhimurium use a different pathway called the phosphonatase pathway, whereas the bacterium Enterobacter aerogenes can use either one of the pathways to cleave the C-P bond found in the alternative phosphates.