No abstract

Increased blood-DNA breakage was observed in diseased pearl oysters. They showed significant formation of 8-hydroxydeoxyguanosine (8-OHdG) and malondialdehyde (MDA), whereas the oysters that had a low mortality rate from the disease had high activity of superoxide dismutase (SOD) and low amounts of 8-OHdG and MDA. These results suggest that radical damage had occurred only in the diseased pearl oysters with the cytolysis of their haemocytes, which was related to the mass mortality of the Japanese pearl oysters.

No abstract

For half a century, Japan has practiced marine stock-enhancement programs that aim to preserve or enhance natural fisheries resources. Currently, juveniles of about 70 marine species are produced in national and prefectural hatcheries, and released annually into the wild (Fisheries Research Agency, 2015a). Because of their high market value, abalone (Haliotidae) are particularly important coastal fishery resources; 30 Japanese governmental entities (city or prefectural governments) currently produce and release the juveniles to enhance stock (Fisheries Research Agency, 2015b). ABSTRACT Candidatus Xenohaliotis californiensis, a Rickettsia-like organism (RLO) that causes 'withering syndrome' (WS) in abalone, has been recently detected in Japan. We analyzed partial nucleotide sequence (113 bp) of 16S rRNA of WS-RLOs (n = 335) from Japanese black abalone Haliotis discus discus, Ezo abalone H. discus hannai, giant abalone H. gigantea, tokobushi abalone H. diversicolor aquatilis and fukutokobushi abalone H. diversicolor diversicolor. All the sequences from Japanese black, Ezo and giant abalone were identical, but different from those from tokobushi and fukutokobushi at one nucleotide position. We also conducted cohabitation challenge to determine whether the WS-RLO in fukutokobushi infects Japanese black and giant abalone or the agent in Japanese black abalone infects fukutokobushi. Twenty fukutokobushi naturally infected with WS-RLO were cohabited with 10 healthy individuals of each of Japanese black, giant, and fukutokobushi abalone for a total of 84 days. At the end of the experiment, surviving fukutokobushi abalone were positive in PCR test for WS-RLO, but negative for that of Japanese black and Ezo abalone. In the reverse combination experiment, in which naturally infected Japanese black abalone were cohabited with these three species, WS-RLO transmissions were found in Japanese black and Ezo, but not in fukutokobushi abalone. These results suggest that two genetic variants of WS-RLO have a different host specificity.

No abstract

Reduction and glycosylation of benzophenone, which is an endocrine disrupting chemical, were investigated using immobilized marine microalga and plant cells from the viewpoint of bioremediation of benzophenone. Immobilized marine microalga of Chrysocampanulla spinifera reduced benzophenone to diphenylmethanol. Immobilized marine microalga of Amphidinium crassum glucosylated diphenylmethanol to the corresponding glucoside. The sequential biotransformation with C. spinifera and A. crassum effectively converted benzophenone into diphenylmethyl glucoside. On the other hand, immobilized plant cells of Catharanthus roseus transformed benzophenone to diphenylmethanol, diphenylmethyl glucoside, and diphenylmethyl primeveroside, which was a new compound, by one-step biotransformation.