Synopsis Microbiology comparatively is a new branch of science which began with the invention of microscope. The present book has been written to meet the specific needs of students of undergraduate and postgraduate classes studying in the colleges and universities of India and abroad. The branch microbiology remained for a long time a discipline almost completely isolated from the rest of biology. Its scope has enlarged tremendously during the last 30 years or so. The efforts in this book are to exploit the development in its economic use. The micro-organisms are vital to economy of any country. The discipline of microbiology is now getting importance in the component of college and university curricula. There are 12 chapters and we are confident by reading this textbook, the reader beside basic concept will also gain an overview of current status and interesting aspects of modern microbiology. The comments and criticisms from the readers are welcomed for the improvement.