The absence of catalase in certain bacteria leads to lactic acid fermentation due to the inability to break down hydrogen peroxide, a byproduct of aerobic respiration. Without catalase, these bacteria cannot efficiently manage oxidative stress, pushing them towards anaerobic pathways like fermentation for energy production. This shift results in the accumulation of lactic acid as the primary metabolic byproduct. Additionally, lactic acid-producing bacteria typically lack specific coenzymes and cytochromes, such as cytochrome c and certain NADH dehydrogenases, which are essential for aerobic respiration. Their absence further reinforces the anaerobic nature of these bacteria, making them reliant on fermentation processes for energy generation.
