Question

Which of the following processes may be considered as an example of biotechnological process?

• A. Treatment of straw with sodium hydroxide
• B. Grinding of straw
• C. Fungal treatment of straw
• D. Ammonia treatment of straw

Hint:

Straw Treatment Categories:
Biological Biotech = WHITE-ROT FUNGI (Pleurotus, Phanerochaete).
Chemical = Urea/Ammonia, NaOH.
Physical = Grinding, Pelleting.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Biological upgradation of crop residues: solid-state fermentation using white-rot basidiomycete fungi utilizes ligninolytic enzymes to biodegrade lignocellulosic bonds.
Key Formula or Approach:
\[ \text{Lignocellulose (Cereal Straw)} \xrightarrow{\text{White-Rot Fungi (Lignin Peroxidase/Laccase)}} \text{Degraded Lignin} + \text{High Digestibility Cellulose/Hemicellulose} \]

Step 2: Detailed Explanation:
Classification of crop residue straw processing treatments:
1. Physical Methods: Grinding, chopping, pelleting, irradiation.
2. Chemical Methods: Treatment with Sodium hydroxide (NaOH), Ammonia ($3\%\text{ NH}_3$), or Urea ammoniation.
3. Biotechnological (Biological) Methods: Fungal treatment of straw (solid-state fermentation using white-rot basidiomycete fungi such as Pleurotus ostreatus, Phanerochaete chrysosporium, or Coprinus fimetarius), which harness secretome enzymes (laccase, lignin peroxidase) to selectively cleave ester lignin-carbohydrate complexes without chemical residues.

Step 3: Final Answer:
Therefore, Fungal treatment of straw is a biotechnological process, corresponding to option (C).