The study of microorganisms living in a variety of environments (air, soil, water, etc.) and their pathogenic relationship to other organisms including man.it includes (a) Microbial community genetics and evolutionary processes (b) element cycles and biogeochemical processes (c) Microbial life in extreme and unusual little-explored environments, (d)Structure and activities of microbial communities (e)Population biology of microorganisms etc. A journal is a periodical publication intended to further progress of science, usually by reporting new research. Most journals are highly specialized, although some of the oldest journals publish articles, reviews, editorials, short communications, letters, and scientific papers across a wide range of scientific fields. Journals contain articles that peer reviewed, in an attempt to ensure that articles meet the journal's standards of quality, and scientific validity. Each such journal article becomes part of the permanent scientific record.