Abstract: The method for treating microcystin-containing water which detoxifies microcystin in the microcystin-containing water, the method comprises the step of: bringing the microcystin-containing water into contact with a Sphingomonas bacterium to degrade biologically the microcystin in the microcystin-containing water, wherein: the Sphingomonas bacterium is a strain FERM P-19480 which is deposited as strain MDB1 with International Patent Organism Depositary, National Institute of Advanced Industrial Science and Technology.

Abstract: The method for treating microcystin-containing water which detoxifies microcystin in the microcystin-containing water, the method comprises the step of: bringing the microcystin-containing water into contact with a Sphingomonas bacterium to degrade biologically the microcystin in the microcystin-containing water, wherein: the Sphingomonas bacterium is a strain FERM P-19480 which is deposited as strain MDB1 with International Patent Organism Depositary, National Institute of Advanced Industrial Science and Technology.

Abstract: The method for treating microcystin-containing water which detoxifies microcystin in the microcystin-containing water, the method comprises the step of: bringing the microcystin-containing water into contact with a Sphingomonas bacterium to degrade biologically the microcystin in the microcystin-containing water, wherein: the Sphingomonas bacterium is a strain FERM P-19480 which is deposited as strain MDB1 with International Patent Organism Depositary, National Institute of Advanced Industrial Science and Technology.

Abstract: The method for treating microcystin-containing water which detoxifies microcystin in the microcystin-containing water, the method comprises the step of: bringing the microcystin-containing water into contact with a Sphingomonas bacterium to degrade biologically the microcystin in the microcystin-containing water, wherein: the Sphingomonas bacterium is a strain FERM P-19480 which is deposited as strain MDB1 with International Patent Organism Depositary, National Institute of Advanced Industrial Science and Technology.

Abstract: In a method of biologically removing nitrogen and a system therefor according to the present invention, by utilizing the characteristics of AH bacteria as being nitrifying bacteria of nitrous acid type for displaying high activity at the high concentration of ammonium nitrogen and the characteristics of AL bacteria as being nitrifying bacteria of nitrous acid type for displaying high activity at the low concentration of the ammonium nitrogen, in the nitrifying process, operations capable of obtaining the maximum nitrifying speed in accordance with the concentration of the ammonium nitrogen can be performed, and the nitrifying reaction of nitrous acid type for producing nitrous acid as being an intermediate oxide material of the ammonium nitrogen can be performed.

Abstract: In a method of biologically removing nitrogen and a system therefor according to the present invention, by utilizing the characteristics of AH bacteria as being nitrifying bacteria of nitrous acid type for displaying high activity at the high concentration of ammonium nitrogen and the characteristics of AL bacteria as being nitrifying bacteria of nitrous acid type for displaying high activity at the low concentration of the ammonium nitrogen, in the nitrifying process, operations capable of obtaining the maximum nitrifying speed in accordance with the concentration of the ammonium nitrogen can be performed, and the nitrifying reaction of nitrous acid type for producing nitrous acid as being an intermediate oxide material of the ammonium nitrogen can be performed.

Abstract: Waste water containing ammonium nitrogen is brought into contact with either one of a catalytically acting substance for converting an ammonium oxidizing product produced by being oxidized by oxidizing bacteria for oxidizing ammonium nitrogen or converting bacteria for reproducing converting capacity of the catalytically acting substance in the aerobic condition.

Abstract: In a method of biologically removing nitrogen and a system therefor according to the present invention, by utilizing the characteristics of AH bacteria as being nitrifying bacteria of nitrous acid type for displaying high activity at the high concentration of ammonium nitrogen and the characteristics of AL bacteria as being nitrifying bacteria of nitrous acid type for displaying high activity at the low concentration of the ammonium nitrogen, in the nitrifying process, operations capable of obtaining the maximum nitrifying speed in accordance with the concentration of the ammonium nitrogen can be performed, and the nitrifying reaction of nitrous acid type for producing nitrous acid as being an intermediate oxide material of the ammonium nitrogen can be performed.

Abstract: In a method of biologically removing nitrogen and a system therefor according to the present invention, by utilizing the characteristics of AH bacteria as being nitrifying bacteria of nitrous acid type for displaying high activity at the high concentration of ammonium nitrogen and the characteristics of AL bacteria as being nitrifying bacteria of nitrous acid type for displaying high activity at the low concentration of the ammonium nitrogen, in the nitrifying process, operations capable of obtaining the maximum nitrifying speed in accordance with the concentration of the ammonium nitrogen can be performed, and the nitrifying reaction of nitrous acid type for producing nitrous acid as being an intermediate oxide material of the ammonium nitrogen can be performed.