Shigeki Fukasawa

Immunochemical Comparisons among Lipopolysaccharides from Symbiotic Luminous Bacteria Isolated from Several Luminous Marine Animals

The luminous marine fish may be divided into those that emit visible light by their own ability and those whose light is produced with the aid of symbiotic luminous bacteria or luminous substances of ingested crustaceans in their light organs (5). The symbiotic luminous bacteria inhabiting the light organs of their hosts are of great interest in regard to whether the relationship between the bacteria and the host is specific or not. Fitzgerald (3) and Reichelt et al (10) reported that certain species of luminous fish possess specific species of luminous bacteria in their light organs. On the other hand, Imai (6) reported that the luminous bacteria isolated from different fishes within the same species are not identical immunochemically. However, more detailed relationships between the hosts and the symbionts have not been clarified. Lipopolysaccharides (LPS) located in the cell walls of gram-negative bacteria not only have diverse biological effects, but also possess an a-antigenic region specific for the bacterial strain. In the present study, we investigated the relationship between the hosts and the symbionts by immunochemically studying the LPS from symbiotic luminous bacteria obtained from several different hosts. In this study, we used symbiotic luminous bacteria, facultative anaerobic enterobacteria, isolated from the light organs of five species (five genera) of luminous fish (Physiculus japonicus [PJ-I], Coelorhynchus kishinouyei [CK-I], and Ventrifossa garmani [VG-I] in the order Gadida; Chlorophihalmus albatrossis [CA-I] in the order Clupeida: and Acropoma japonicum [AJ-I b] in the order Percida) and from the light organ ofa luminous squid tDoryteuthis kensaki [DK-I]). For the name of the luminous bacterium isolated from each host, the abbreviation given in brackets ([]) is used hereafter. The morphological aspects and the derivations of these symbionts have been reported by Fukasawa (4). We identified luminous bacteria PJ-I, CK-I, VG-I, and CA-I as Photobacterium phosphoreum from the results obtained by comparison with the criteria of Bergeys manual (8th edition) (I) and with standard

Growth and luminescence of luminous bacteria on modified Haneda's medium.

Shigeki FUKASAWA,*,1 Paul DUNLAP,2 Yoshimi BENNO,3 and Tomotari MITSUOKA3,4 1 Department of Biochemistry, Faculty of Science, Josai University, Sakado, Saitama 350-02, 2 Department of Biology, University of California at Los Angeles, Los Angeles, Calif. 90024, U.S.A., 3The Institute of Physical and Chemical Research, Wako, Saitama 351, and 4Department of Biomedical Science, Faculty of Agriculture, The University of Tokyo, Bunkyo-ku, Tokyo 113

Relationship between Luminous Fish and Symbiosis

In order to investigate the relationship between host and symbiosis in the luminous marine fish, Physiculus japonicus, the bacterial lipopolysaccharides (LPS) of symbiotic luminous bacteria were compared serologically and electrophoretically.

A comparison of the bacteriocupreins in crude extracts of Photobacterium leiognathi isolated from squid and fish

Abstract (1) Four strains of Photobacterium leiognathi were isolated from the light organs of a squid, Doryteuthis kensaki , and a fish, Acropoma japonicum , and surfaces of squid skin. Cu,Zn-containing superoxide dismutases (bacteriocupreins) and Fe-containing superoxide dismutases in crude extracts of the four strains and a type strain, ATCC 25521, were compared by using activity measurement, isoelectric focusing, and cyanide sensitivity. The results indicate no significant variation of the superoxide dismutases between the different strains. (2) The effects of metal nutrition on the superoxide dismutase activity of the crude extracts from the five strain of Photobacterium were compared. The contents of bacteriocuprein in the crude extracts were increased when iron was omitted and copper and zinc were supplemented in the medium. From these results it was concluded that the bacteriocupreins of the different strains of P. leiognathi have the same properties regardless of the difference of host species or collected sources.

Induction of superoxide dismutases in Photobacterium leiognathi.

We investigated the induction of Cu,Zn-SOD (bacteriocuprein) and Fe-SOD in Photobacterium leiognathi DK-A1 which was isolated from the light organ of the squid, Droteuthis kensaki. The induction of superoxide dismutases depended on the addition of paraquat to the medium. Induction of SOD by paraquat was attributed mostly to the bacteriocuprein by measuring of the activities of both SODs by using densitometry of isoelectrofocusing gel. When paraquat was added to the culture at various times in the early log phase of growth, the most efficient induction of the SODs, which was measured at the time of harvesting the cells (17 hours after inoculation), was observed when paraquat was added at 60 min after the inoculation. Catalase was not significantly induced by the addition of paraquat or increasing of oxygen concentration. We developed an assay of SOD by modification of a cytochrome c-xanthine oxidase method using a computer equipped absorption spectrophotometer.