Role of vegetable oils in penicillin fermentations — functional contributions in the production broth When corn or soybean oil is added to a penicillin fermentation medium, what are its principal roles?

Introduction / Context:
Adjuncts such as vegetable oils are commonly incorporated into antibiotic fermentations. They influence oxygen transfer, foam control, and provide slowly metabolized energy or precursors that benefit product formation and process stability.

Given Data / Assumptions:

• Oils considered: corn oil or soybean oil.
• Process: aerobic, foam-prone stirred-tank fermentation for penicillin.
• Desired outcomes: stable foam control and supportive nutrient contribution.

Concept / Approach:

Vegetable oils serve dual roles: (1) as antifoam agents reducing surface tension and preventing excessive foam that would otherwise cause contamination risk and gas–liquid transfer issues, and (2) as nutrient supplements providing lipids/fatty acids that can act as a slowly available energy source and influence cell physiology. While they may contribute carbon, they are not typically the sole or primary carbon source in penicillin runs (lactose and other carbohydrates often fill that role).

Step-by-Step Solution:

Verification / Alternative check:

Process descriptions for penicillin production routinely list vegetable oils among antifoam choices and as slowly utilized carbonaceous additions that can improve titers.

Why Other Options Are Wrong:

Option b exaggerates the role of oil as a primary carbon source; typically, sugars are main carbon. Option e (pH control) is indirect at best; oils are not primary pH agents.

Common Pitfalls:

Overdosing antifoam can reduce oxygen transfer; balance antifoam addition with aeration needs.

Final Answer:

Both (a) and (c)