Question

Match List I with List II
List I (Abnormal Colouration):
A. Blue colouration
B. Yellow colouration
C. Red colouration
D. Green colouration
List II (Causative Organism):
I. Pseudomonas synxantha
II. Pseudomonas syncyanea
III. Serratia marcescens
IV. Chromobacterium violacein
V. Pseudomonas fluorescence
Choose the correct answer from the options given below:

• A. A - II, B - I, C - III, D - V
• B. A - II, B - III, C - IV, D - V
• C. A - III, B - IV, C - I, D - V
• D. A - IV, B - I, C - II, D - III

Hint:

Associate the species names with Latin roots of colors: "cyan-" means blue (syncyanea $\rightarrow$ blue), "xanth-" means yellow (synxantha $\rightarrow$ yellow), and "fluorescens" relates to fluorescent green.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Bacterial contamination of milk can lead to abnormal color defects due to the production of water-soluble or cellular pigments during growth.

Step 2: Detailed Explanation:
Let us match the abnormal colorations with their respective causative bacterial species:
- A. Blue colouration: This is caused by Pseudomonas syncyanea (II) (formerly Vibrio syncyaneus), which produces a bluish pigment in slightly sour milk, often in association with acid-producing cocci.
- B. Yellow colouration: This is caused by Pseudomonas synxantha (I), which hydrolyzes fat and produces a yellow, water-soluble pigment in the cream layer.
- C. Red colouration: This is caused by Serratia marcescens (III), which produces a bright red, water-insoluble pigment called prodigiosin.
- D. Green colouration: This is caused by Pseudomonas fluorescens (V) (spelled fluorescence in the question), which produces a water-soluble, fluorescent green-yellow pigment called pyoverdine, especially under refrigerated conditions.
This results in the matching sequence: A-II, B-I, C-III, D-V.

Step 3: Final Answer
The correct option is (A).