(1) Psychrophilic methanogens play a very important role in global carbon cycle, and attract more and more research interests.

(2) The isolation of psychrophilic methanogens, the mechanisms of cold adaptation, and the molecular biology, were also discussed.

(3) The Psychrophilic bacteria is one of the reasons that cause a variety of harmful effects of low temperature preserve food products.

(4) He said: "This finding also shows that psychrophilic microbial degradation of oil abound, their Gulf of Mexico after the final status of oil pollution control plays an important role."

(5) The article summarizes methanogenesis under low-temperature conditions, including methanogenesis in natural cold environments and in artificial anaerobic digesters by psychrophilic methanogen.

(6) Besides, though isozyme 4 derived from a mesophile, it showed thermosensitive just like the psychrophilic catalase, so we describe it as a cold-adapted enzyme.

(7) In order to research the method to solve the problems, the paper studied the Psychrophilic bacteria in the raw milk preserved in low temperature.