Tetracycline is an antibiotic which is obtained from bacteria Streptomyces aureofaciens. It inhibits translation process in protein synthesis by inhibiting the binding of aminoacyl fRNA to ribosome. Calvacin is an anticancer substance obtained from fungus Clavatia and it is eaten to prevent tumour formation in stomach. Citric acid is an organic acid produced by fungus Aspergillus niger. Ergotamine is also of fungal origin, obtained from Claviceps purpurea.