What specific conditions does Bacillus subtilis need to be in to form endospores?
Most Bacillus species are versatile chemoheterotrophs capable of respiration using a variety of simple organic compounds (sugars, amino acids, organic acids). In some cases, they also ferment carbohydrates in a mixed reaction that typically produces glycerol and butanediol. A few species, such as Bacillus megaterium, require no organic growth factors; others may require amino acids, B-vitamins, or both. The majority are mesophiles, with temperature optima between 30 and 45 degrees, but the genus also contains a number of thermophilic species with optima as high as 65 degrees. In the laboratory, under optimal conditions of growth, Bacillus species exhibit generation times of about 25 minutes. Bacillus species are easily isolated and readily grown in the bacteriology laboratory. The simplest technique that enriches for aerobic spore formers is to pasteurize a diluted soil sample at 80 degrees for 15 minutes, then plate onto nutrient agar and incubate at 37 degrees for 24 hours up to seve
