Industrial fermentation practice: To maintain aseptic (sterile) conditions throughout a batch or fed-batch run, which measures are required?

Introduction / Context:
Asepsis is critical in bioprocessing to prevent contamination that can ruin yields and product quality. Maintaining sterility is a system-level discipline, not a single step.

Given Data / Assumptions:

• A typical aerobic fermentor requires sterile vessel, sterile media, and sterile air.
• Mechanical assemblies (seals, impellers) must not introduce contaminants.
• Continuous operation demands asepsis for the entire duration.

Concept / Approach:
Sterilisation-in-place (SIP) and clean-in-place (CIP) prepare the fermentor. Inlet gases are sterilised via filters. Agitation/aeration hardware must use sanitary design (mechanical seals, steam barriers) to keep the system closed and sterile under operating conditions.

Step-by-Step Solution:

Verification / Alternative check:
GMP guidelines and standard bioprocess manuals prescribe all three elements as mandatory for aseptic fermentation.

Why Other Options Are Wrong:

Common Pitfalls:
Assuming air sparging is inherently sterile; it must pass through validated filters and sterile piping.

Final Answer:
All of these.