Fermentation end products

• glucose or other carbohydrates can undergo fermentation

• pyruvate and then end products of fermentation are formed

• the fermentation pathway of an organism has been very useful in terms of classifying and identifying bacteria and byproducts have been the subject of diagnostic tests

• Streptococci form lactic acid

• Propionibacteria form propionic acid; the irritation caused by proprionic acid is what partly causes the clinical complaints of acne

• Some enterobacteriace, such as E. coli, can break formic acid into CO₂ and H₂, and this is where the gas comes from; CO₂ rapidly diffuses into host tissue, but H₂ does not. this primarily occurs in diabetics

• Other bacteria produce other products of fermentation

  • Klebsiella produces butanediol

  • Clostridia produces butyric acid

  • yeast, which is not a bacteria, produces ethanol

• Explain how Pseudomonas aeruginosa can be facultative when it cannot derive energy from fermentation

  • Pseudomonas cannot ferment; it lacks the metabolic pathways that allow it to ferment carbohydrates and there is no way it can produce gas as an end product of fermentation

  • what does facultative mean?

Category: Microbiology Notes