The proposed book aims to understand the mechanism of survival of microorganisms in response to chemical stress in various ecological niches that suffer direct human intervention, more so the agricultural, domestic and hospital settings. Microbicides (e.g. disinfectants, antiseptics, fungicides, algaecides, insecticides and pesticides) are used rampantly to control undesirable microbes. Insecticides and pesticides are routinely used in agriculture which directly affect the microbial population in farms, orchards and fields. Health care environments are always stressed with disinfectants and antibiotics. It is always probable that microbicide-stressed microorganisms are in a dynamic state, displaced from one niche to the other. Some soil and water borne bacteria or their