Question 1

Differentiate between primary and secondary metabolites based on their functions with example.

Accepted Answer

Primary metabolites are compounds produced during the active growth phase of microorganisms and are directly involved in normal growth, development, and reproduction. Examples include amino acids, nucleotides, and ethanol. Secondary metabolites are compounds produced during the stationary phase or after the active growth phase and are not directly involved in growth but have ecological functions such as defense. Examples include antibiotics like penicillin and alkaloids. — Primary metabolites are essential for cell growth and metabolism, produced during the exponential phase. Secondary metabolites are produced later and often serve ecological roles such as defense or competition.

Question 2

Explain the challenges encountered during the development of a bioprocess.

Accepted Answer

Challenges in bioprocess development include: maintaining sterile conditions to avoid contamination, optimizing growth conditions for maximum yield, scaling up from lab to industrial scale while maintaining product quality, controlling parameters like pH, temperature, oxygen supply, and nutrient availability, dealing with product inhibition or toxicity, and ensuring cost-effectiveness and regulatory compliance. — Each stage of bioprocess development requires careful control and optimization to ensure efficient production. Contamination can ruin batches, scaling up can change dynamics, and product recovery can be complex.

Question 3

Describe briefly the design and components of a typical bioreactor and their applications.

Accepted Answer

A typical bioreactor consists of a vessel equipped with components such as an agitator for mixing, sparger for aeration, baffles to prevent vortex formation, and a jacket for temperature control. The agitator ensures uniform mixing of nutrients and cells; the sparger supplies air or oxygen; baffles improve mixing efficiency; and the jacket circulates water or steam to maintain optimal temperature. Applications include fermentation for production of antibiotics, enzymes, vaccines, and other bioproducts. — Each component plays a critical role in maintaining optimal growth conditions and ensuring efficient bioprocessing. The design allows control over physical and chemical parameters.

Question 4

Explain the basic operational stages of a bioprocess using concept map.

Accepted Answer

The basic operational stages of a bioprocess include: (1) Upstream processing - preparation of inoculum, media formulation, sterilization; (2) Bioreaction - cultivation of microorganisms or cells in bioreactor under controlled conditions; (3) Downstream processing - recovery, purification, and formulation of the product. A concept map would show these stages sequentially with arrows indicating flow from inoculum preparation to product recovery. — Understanding the stages helps in designing and optimizing the entire bioprocess from start to finish.

Question 5

Describe briefly the following:
(a) upstream processing
(b) downstream processing

Accepted Answer

(a) Upstream processing involves all steps before the actual bioreaction, including selection of microorganisms, preparation of culture media, sterilization, and inoculum development.
(b) Downstream processing involves the recovery and purification of the product from the culture broth, including cell separation, extraction, purification, and formulation. — Upstream focuses on preparing for the bioprocess, while downstream focuses on product recovery and purification.

Question 6

Explain the recovery and purification process of an intracellular product with the help of a flow diagram.

Accepted Answer

Recovery and purification of intracellular products involve: (1) Cell disruption to release the product (methods include sonication, homogenization, enzymatic lysis); (2) Removal of cell debris by centrifugation or filtration; (3) Purification steps such as precipitation, chromatography, dialysis, or ultrafiltration; (4) Final formulation of the purified product.

Flow diagram:
Cell culture → Cell disruption → Centrifugation/Filtration → Purification (precipitation/chromatography) → Formulation — Intracellular products require cell breakage to access the product, followed by separation and purification steps to obtain a pure product.

Question 7

Write short notes on the following:
(a) reverse osmosis
(b) dialysis

Accepted Answer

(a) Reverse osmosis is a process where solvent molecules pass through a semipermeable membrane from a region of higher solute concentration to lower concentration by applying pressure greater than osmotic pressure, used for water purification.
(b) Dialysis is a process of separating small molecules from macromolecules in solution by diffusion through a semipermeable membrane, used for purification and removal of waste products. — Both are membrane-based separation techniques used in bioprocessing for purification and concentration.

Question 8

Match the following:
(a) Agitator
(i) Breaking the vortex formation
(b) Sparger
(ii) Provides area for circulation of water of desired temperature
(c) Baffle
(iii) Helps in mixing the contents
(d) Jacket
(iv) Provides adequate and continuous supply of air

Accepted Answer

Correct matching:
(a) Agitator - (iii) Helps in mixing the contents
(b) Sparger - (iv) Provides adequate and continuous supply of air
(c) Baffle - (i) Breaking the vortex formation
(d) Jacket - (ii) Provides area for circulation of water of desired temperature — Agitator mixes the culture, sparger supplies air, baffles prevent vortex formation improving mixing, and jacket controls temperature by circulating water.

Question 9

A culture in a closed vessel to which no additional medium is added is called ___________ culture.
(a) Continuous
(b) Batch
(c) Fed-batch
(d) Semi continuous

Accepted Answer

Answer: (b) Batch culture.

Explanation: In batch culture, the culture is grown in a closed vessel with a fixed volume of medium and no addition of fresh medium during the process. This contrasts with continuous culture where fresh medium is continuously added. — Batch culture involves no addition of medium after inoculation, making it a closed system.

Question 10

Assertion: Secondary metabolites are used in defense against pathogens, phytoplanktons, improving tolerance to abiotic, etc.
Reason: Secondary metabolites are intermediate or indirect products.
(a) Both assertion and reason are true and the reason is the correct explanation of the assertion.
(b) Both assertion and reason are true but the reason is not the correct explanation of the assertion.
(c) Assertion is true but reason is false.
(d) Both assertion and reason are false.

Accepted Answer

Answer: (a) Both assertion and reason are true and the reason is the correct explanation of the assertion.

Explanation: Secondary metabolites serve ecological functions such as defense against pathogens and environmental stresses. They are not primary metabolic products but are produced as intermediate or indirect products during later stages of growth. — The assertion is true because secondary metabolites have defensive roles. The reason correctly explains that these metabolites are intermediate or indirect products, confirming option (a).

Question 11

Which of the following best defines primary metabolites in bioprocessing?

Accepted Answer

Compounds produced directly from primary metabolic pathways essential for growth and development — Primary metabolites are chemical compounds produced directly through primary metabolic pathways that are essential for cellular functions such as growth and development. They include amino acids and organic acids. Secondary metabolites, in contrast, are produced via secondary metabolic pathways and serve ecological roles such as defense or attraction.

Question 12

Secondary metabolites serve various ecological functions. Which of the following is NOT a function of secondary metabolites?

Accepted Answer

Direct involvement in primary metabolic pathways for energy production — Secondary metabolites are not directly involved in primary metabolic pathways such as energy production. Instead, they serve ecological roles like defense, attraction, and stress tolerance. Primary metabolites are involved in essential cellular functions including energy production.

Question 13

Identify the scientist who discovered penicillin in 1928, which marked a breakthrough in bioprocessing.

Accepted Answer

Alexander Fleming — Alexander Fleming discovered penicillin in 1928 when he observed that a mold, later identified as Penicillium notatum, inhibited bacterial growth. This discovery was foundational for bioprocessing development.

Question 14

The diagram shows a typical bioreactor with labeled components: agitator shaft, sparger, baffle, jacket, and probes. Which component is responsible for providing sterile air to the culture medium?

Accepted Answer

Sparger — The sparger supplies sterile air (oxygen) continuously to the culture medium through microfilters, ensuring adequate aeration for cellular respiration.

Question 15

What is the primary function of baffles in a bioreactor?

Accepted Answer

To break vortex formation and stabilize the system — Baffles prevent the formation of vortices during agitation, which can destabilize the system and increase power consumption.

Bioprocessing and Biomanufacturing

Bioprocessing and Biomanufacturing — Study Notes

Introduction to Bioprocessing and Biomanufacturing

10.1 Historical Perspective

10.2 Instrumentation in Bioprocessing: Bioreactor and Fermenter Design

Practice Questions — Bioprocessing and Biomanufacturing

All 13 Chapters in Biotechnology