Microbes (or microorganisms) are organisms that are too small to be seen by the unaided eye. They include bacteria, fungi, protozoa, microalgae, and viruses. Microbes live in familiar settings such as soil, water, food, and animal intestines, as well as in more extreme settings such as rocks, glaciers, hot springs, and deep-sea vents. The wide variety of microbial habitats reflects an enormous diversity of biochemical and metabolic traits that have arisen by genetic variation and natural selection in microbial populations. Dr ML. Mohammed Kaleem Arshan is currently working as an Assistant Professor in the Department of Biotechnology, Islamiah College (Autonomous), Vaniyambadi India. He earned his B.Sc., M.Sc. degree from same College and PhD in Marine Biology. He has published 26 research articles,7 chapters in Reputed National and International Journals. He won Best Scientist Award in Marine Ecology for the year 2018. He has deposited 100 DNA sequences in GenBank, NCBI, USA. To his credit, he had discovered TWO New Species which are new to science and also created 51 DNA barcodes for 25 species in Barcode of Life Database.