Question

why do e say that all microorganisms are not harmful give2 eg

Answer 1

Not all microbes are harmful. Some microbes like lactobacillus is used to make curds from milk. Cheese and vinegar are also produced with the help of bacteria.
Furthermore, many medicines and antibiotics are made from bacteria. Penicillin, streptomycin and erythromycin are antibiotics that are made from bacteria,

Answer 2

$\bf\huge\color{Red}{Hello\:User}$

We say that all the microorganisms are not harmful as there are many microbes that are really useful to us.
Eg:-
● Lactobacillus :- it is a microbe that us used to prepare curd.
● yeast :- it us a microbe that is used to make bread and alcohol
● There are some microbes that are used to prepare antibiotics. such as penicillin and streptomycin.