If you are a farmer or a student of agriculture, then you must be aware of the importance of microorganisms in soil fertility and crop production. Antibiotics produced by organisms helps in the inhibition of certain pathogenic organism that can be inimical to plant production. Patulan and viridian are examples of some of these antibiotics while others such as subtilin can be used in food preservation. These post explains more on this subject http://gulpmatrix.com/antibiosis-uses-of-antibiotics-in-medicine-and-agriculture/