Select the correct statement regarding lactobacillus acidophilus.
A. They produce acids the coagulate and partially digest milk fat.
B. They require a suitable temperature and medium for their multiplication.
C. They play a beneficial role by checking disease-causing microbes in our stomach.
D. They improve nutritional quality by increasing the amount of thiamine .

Options

A. (A) , (B) and (C)
B. (B) and (C)
C. (B) , (C) and (D)
D. All of these

Answer

To solve the question regarding the correct statements about Lactobacillus acidophilus, we will analyze each option one by one.

### Step-by-Step Solution:

1. **Statement A: They produce acids that coagulate and partially digest milk fat.**
- **Analysis:** Lactobacillus acidophilus primarily ferments lactose (milk sugar) to produce lactic acid. This acid primarily acts on milk proteins (casein) rather than milk fat. Therefore, this statement is incorrect.

2. **Statement B: They require a suitable temperature and medium for their multiplication.**
- **Analysis:** Lactobacillus acidophilus, like all bacteria, requires specific conditions for optimal growth, including a suitable temperature (usually around 37°C for LAB) and an appropriate medium (like milk). This statement is correct.

3. **Statement C: They play a beneficial role by checking disease-causing microbes in our stomach.**
- **Analysis:** Lactobacillus acidophilus is known for its probiotic properties, which include inhibiting the growth of pathogenic bacteria in the gut. This statement is also correct.

4. **Statement D: They improve nutritional quality by increasing the amount of thiamine.**
- **Analysis:** While Lactobacillus acidophilus does contribute to the nutritional quality of fermented products, it is more associated with increasing levels of vitamin B12 rather than thiamine. Therefore, this statement is incorrect.

### Conclusion:
Based on the analysis:
- **Correct Statements:** B and C
- **Final Answer:** The correct options are B and C.