NITKOGEIV cycle is disturbed by human activities, while some nitrogenous compounds are harmful to hu- man health. When large amounts of nitrogenous compounds such as protein, urea, etc., which can bedegraded to NH_4~+ by microbes, enter waters, some of them are assimilated to biomass, but most are stillin waters. In the presence of oxygen, NH_4~+ are oxidized to NC_2~- and NO_3~- by autotrophic bacteria. Inanoxic phase, denitrifiers such as Pseudomonas Migula, Achromobacteaceae, Bacillus and Micrococcus,etc. will proceed denitrification, utilizing N0_3~- as the terminal electron acceptor instead of O_2 in the respiratory chain. Because bacteria denitrification, involving four steps from NO_3~- to NO_2~-, NO, N_2O andN_2, in fact, is an enzymatically catalytic process, changes of environmental factors such as concentration NITKOGEIV cycle is disturbed by human activities, while some of the nitrogenous compounds are harmful to hu- man health. When large amounts of nitrogenous compounds such as protein, urea, etc., which can be degraded to NH_4 ~ + by microbes, enter waters, some of Inanoxic phase, denitrifiers such as Pseudomonas migula, Achromobacteaceae, Bacillus and Micrococcus, Nutraceuticals, Because bacteria denitrification, involving four steps from NO_3 ~ - to NO_2 ~ -, NO, N_2O andN_2, in fact, is an enzymatically catalytic process, changes of environmental factors such as concentration