Microorganisms

State the uses of xanthan gum that is obtained by microbial process.
Koch's postulates are not applicable to
Arrange the following in the decreasing order (most important first their importance, for the welfare or human society. Give reason for your answer). Biogas, Citric acid, Penicillin and Curd.
"Long back, cheese was not considered as vegetarian food". Why?
The gram negative bacteria detect and respond to
chemicals in their surroundings by