This book offers a comprehensive overview of the microbiological fundamentals and biotechnological applications of methanotrophs: aerobic proteobacteria that can utilize methane as their sole carbon and energy source. It highlights methanotrophs’ pivotal role in the global carbon cycle, in which they remove methane generated geothermally and by methanogens. Readers will learn how methanotrophs have been employed as biocatalysts for mitigating methane gas and remediating halogenated hydrocarbons in soil and underground water. Recently, methane has also attracted considerable attention as a potential next-generation carbon feedstock for industrial biotechnology, because of its abundance and low price. Methanotrophs can be used as biocatalysts for the production of fuels, chemicals and biomaterials including methanobactin from methane under environmentally benign production conditions. Sharing these and other cutting-edge insights, the book offers a fascinating read forall scientists and students of microbiology and biotechnology.