Final answer:
Reducing media are used to cultivate anaerobic bacteria and Archaea, like methanogens and sulfate-reducing bacteria, which do not require oxygen to grow.
Step-by-step explanation:
Reducing media are generally used to grow anaerobic organisms, which are types of prokaryotes that thrive in environments lacking oxygen.
These organisms use anaerobic respiration to metabolize substances, often relying on different substances as terminal electron acceptors.
For instance, methanogens, a type of Archaea, are notable for reducing carbon dioxide into methane to regenerate NAD+ from NADH and are commonly found in the digestive tracts of ruminants and soil.
Additionally, sulfate-reducing bacteria decrease sulfate to hydrogen sulfide in a similar fashion.
These microbes are important in many ecological processes and need specialized culture media that reduce the potential for oxygen to interrupt their growth.
Selective media like MacConkey agar is used for growing specific types of bacteria by suppressing others and is an example of how media can be tailored to the needs of particular microorganisms.
On the other hand, some bacteria such as hydrocarbonoclastic bacteria are enriched in specific media to isolate them due to their ability to break down crude oil.
These bacteria can be identified using selective and differential media which make it easier to distinguish between bacterial colonies.