Step 1: Core Concept:
Cheese production has two microbial phases: initial fermentation by starter cultures and a subsequent ripening stage using secondary microflora. The question focuses on microorganisms active in the initial stages.
Step 2: Breakdown:
The early stage of cheesemaking involves fermenting lactose (milk sugar) into lactic acid. This acidifies the milk, crucial for curd formation (coagulation) and preventing spoilage. These are the starter cultures.
(A) Brevibacterium linens: This bacterium is part of the secondary flora, responsible for ripening certain cheeses, such as Limburger and Muenster. It produces the orange-red rind and strong aroma. It is a ripening agent, not an early-stage culture.
(B) Penicillium candidum: A mold used for ripening soft cheeses like Camembert and Brie. It forms the white, "bloomy" rind. This is a ripening agent.
(C) Lactococcus cremoris: A Lactic Acid Bacterium (LAB), a common and important mesophilic starter culture in cheeses like Cheddar and Gouda. It performs the initial lactic acid fermentation.
(D) Lactococcus lactis: Another key Lactic Acid Bacterium, often used with L. cremoris as a primary mesophilic starter culture. It is essential for the early acidification.
Step 3: Conclusion:
Both Lactococcus cremoris and Lactococcus lactis are primary starter cultures, responsible for the initial fermentation in early cheese production. Thus, (C) and (D) are the correct answers.