A large number of antibiotics have been isolated from 

Question : A large number of antibiotics have been isolated from

(1) bacteria Actinomycetes.

(2) bacteria Staphylococcus.

(3) bacteria Rhizobium.

(4) acids.

Answer : from all above options the correct answer is “(1) bacteria Actinomycetes. ”

Explanation of answer : After the discovery of penicillin In 1928 by Alexander Fleming at St. Mary’s Hospital, London , the bacteria Actinomycetes were exploited to give a series of antibiotics. as we know that Actinomycetes are considered as heterogeneous group of gram positive , now you should know that gram positive bacteria are those bacteria which give a positive result when Gram stain test on them that is why Actinomycete is a group of gram positive. when penicillin was discovered by Alexander Fleming in the year of 1928 , and the result come from it , that  A large number of antibiotics have been isolated from bacteria Actinomycetes that is why we have correct correct answer “(1) bacteria Actinomycetes.“