Characterization of a Bacterium (A-1) That Decomposes Ferric Chelate of EDTA in Photographic Processing Waste Solutions

Hideo Miyazaki^a Seiji Suzuki^a Hiroshi Tsujibo^b and Katsumi Imada^c�

^aAshigara Res. Labs., Fuji Photo Film Co., Ltd., 210 Nakanuma, Minamiashigara, 250−0193, Japan, ^bLaboratory of Microbiology, Osaka University of Pharmaceutical Sciences, 4−20−1 Nasahara, Takatsuki, 569−1094, Japan and ^cFaculty of Agriculture, Tokyo University of Agriculture, 1−1−1 Sakuraoka, Setagaya-ku, Tokyo 156−8502, Japan

Ferric-EDTA(Fe-EDTA)-degrading bacterium, strain A-1 was characterized by its physiological properties. The rate of degradation of Fe-EDTA was measured by the titration method and ion chromatography. The former method has the advantage of allowing a greater number of sample measurements of samples at one time. The rate of degradation of Fe-EDTA was higher in a stationary culture than in a shaked one. The optimum pH for the degradation rate was approximately 8.2. Strain A-1 grew in the presence of various kinds of metal-EDTA chelates, but a Na salt, Mg and Ca chelates of EDTA inhibited the growth. Their MICs (minimual inhibitory concentration) were 0.0045, 0.03 and 0.006 %, respectively. These characteristics of strain A-1 have similarities to those of strain B-3, but were different from those of Agrobacterium sp. which were reported by Lauff previously (Appl. Environ. Microbiol., 56, 3346 (1990)). All of the detail taxonomic characters indicate that the isolate strain A-1 belongs to a Pseudomonas sp.