Medical Laboratory Scientist (MLS) ASCP Exam 2025 – 400 Free Practice Questions to Pass the Exam

The absence of cytochrome oxidase activity indicates an organism that primarily ferments carbohydrates. This finding is particularly relevant within the family Enterobacteriaceae, which encompasses a variety of gram-negative bacteria known for their ability to ferment sugars.

In essence, bacteria that do not exhibit cytochrome oxidase activity often rely on anaerobic respiration or fermentation processes rather than aerobic respiration. Cytochrome oxidase is a component of the electron transport chain utilized in aerobic respiration; therefore, the absence of this enzyme suggests that the organism does not engage in this metabolic pathway. Instead, these bacteria typically ferment carbohydrates to produce energy, a characteristic feature of many members of Enterobacteriaceae.

This understanding directly correlates with the biochemical characteristics and metabolic capabilities of bacteria within this group, supporting the classification and identification processes in microbiological laboratory practices.