alicyclobacillus hesperidum alicyclobacillus hesperidum alicyclobacillus hesperidum is a species of gram positive, strictly aerobic, bacterium. the bacteria are acidophilic and produced endospores. it was first isolated from solfataric soils in the furnas, the azores. the species was first described in 2000, and the name refers to the hesperides, "mythological figures whom the greeks believed to have lived at the western edge of the earth in a miraculous garden, which interpret as the azores." alicyclobacillus hesperidum scientific classification domain: bacteria phylum: bacillota class: bacilli order: bacillales family: alicyclobacillaceae genus: alicyclobacillus species: a. hesperidum binomial name alicyclobacillus hesperidumalbuquerque et al. 2000 the optimum growth temperature for a. hesperidum is 50-53 °c, and can grow in the 35-60 °c range. the optimum ph is 3.5-4.0, and can grow in ph 2.5-5.5.