University of Central Florida (UCF) MCB2004 Microbiology for Health Professionals Practice Exam 2

Auxotrophs and prototrophs are terms used to describe the nutritional requirements of microorganisms, specifically in their ability to synthesize compounds needed for growth.

Prototrophs are capable of synthesizing all the compounds they need for growth from basic nutrients. They can utilize simple inorganic compounds and are not dependent on any additional organic nutrients for their growth. This ability to thrive on minimal organic substances is what differentiates them fundamentally from auxotrophs.

On the other hand, auxotrophs have lost the ability to synthesize certain essential compounds due to mutations. As a result, they require additional organic substances in their growth media to supplement their deficiencies. This means they are unable to grow when only provided with minimal simple inorganic nutrients, unlike prototrophs.

Thus, the notion that prototrophs require no additional organic nutrients reflects their self-sufficiency in nutrient synthesis, making it a defining characteristic compared to auxotrophs.