RYOTA SAITO, TATSUYA SAKAI, TAIGA SHIMIZU, KAITO MIZUMACHI, RYOTA KOIZUMI, TAIKI ONO AND YOICHIRO SOGAME
Abstract
Chlorophthalmus is a greeneye genus of deep-sea fish harboring symbiotic luminous bacteria near their anus. Chlorophthalmus borealis called âMehikariâ in Iwaki City (Fukushima Prefecture, Japan) is a symbol of the City but its morphological and ecological features are poorly understood, including the generality of this symbiosis with luminous bacteria. We performed molecular phylogenetic analysis of a symbiotic luminescent bacterial strain isolated from C. borealis collected near the coast of Fukushima. The results showed that the luminous bacterium was Photobacterium kishitanii, and a novel culture strain was established as P. kishitanii Taigaleon. The emission intensity of P. kishitanii Taigaleon, an emission maximum at 475 nm, differed depending on the age and state of the culture as determined by confocal laser microscopy and fluorescence spectrophotometer. In this study we tried to detect and evaluate the harm of ammonia by biological assays using living-whole cell P. kishitanii Taigaleon, because they respond to external factors and their emission intensity changes. In this paper, we discuss the possibility of using P. kishitanii Taigaleon to assess water samples for harmful ammonia.