ALBERT

Notes: Tanier spinach (Xanthosoma brasiliense, Araceae) is a common leafy vegetable in south-eastern Brazil. A cuneiform leaf blight which started at the edges of leaves and resulted in complete leaf decay has recently been observed. The causal agent was identified as Pseudomonas cichorii. This appears to be the first report of the disease.

Notes: Peruvian carrot soft rot occurs quite frequently in Minas Gerais State, Brazil, either under field conditions or after harvested roots have been stored. The etiology of the disease was investigated and the disease was found to be induced by Erwinia carotovora. This appears to be the first report of this disease.

Notes: The mechanism of thermal degradation of inosine 5′-monophosphate (IMP) and guanosine (GMP) was investigated kinetically in aqueous solution as a function of pH and temperature. The degradation of IMP and GMP followed first order kinetics. The rate constants were considerably affected by pH and temperature. The half-life times at 100°C were: IMP, 8.7 hr (pH 4.0), 13.1 hr (pH 7.0), 46.2 hr (pH 9.0); GMP, 6.4 hr (pH 4.0), 8.2 hr (pH 7.0), 38.5 hr (pH 9.0). These times were shortened to about one-third by raising the temperature 10°C. The predominant degradation products were nucleosides and phosphoric acid, indicating that the main reaction of the thermal degradation was the hydrolysis of the phosphoric ester bond in the nucleotides.

Notes: Water samples collected from raceway of salmonid hatcheries in Japan in each of the four seasons were compared for their capability to reduce the infectivity titres of infectious hematopoietic necrosis virus (IHNV) and infectious pancreatic necrosis virus (IPNV).The titre of IHNV was reduced at 15 °C to less than detectable limits within 3 days using untreated samples of water and samples of water containing sedimenis. Little reduction of infectivity of IPNV was observed in all water samples. No reduction of infectivity was noted for either virus using bacteria-free water treated by filtration or autoclaving. Results were similar with the water obtained during each season. After incubation of the samples, the nu̇mber of viable bacteria increased 102–103-fold. Members of the genus Pseudomonas were mosl predominant in the water and sediment samples.Bacteria isolated from the water collected from a salmonid hatchery in spring, 1984 were screened for anti-IHNV activity.Three of 25 isolates showed anti-IHNV activity (plaque reduction of more than 50 %) in the culture filtrates, including one Pseudomonas strain showing potenl anti-IHNV activity (99 % plaque reduction).〈section xml:id="abs1-2"〉〈title type="main"〉ZusammenfassungDer Einfluß des Fischhälterungswassers auf die Infektiosität des Virus der infektiösen haematopoetischen Nekrose (IHNV) und des Virus der Pankreasnekrose (IPNV)Saisonal entnommene Wasserproben aus Forellenzuchtbetrieben in Japan wurden hinsichilich ihrer inaktivierenden Wirkungen auf das Virus der haematopoetischen Nekrose (IHNV) und das Virus der Pankreasnekrose (IPNV) untersucht. Während unbehandelte Wasserproben und Wasserproben mit Sedimenl die Infektiosität des IHNV bei 15 °C fast völlig innerhalb 3 Tagen reduzierten, erwies sich die Infekliosität des IPNV als relaliv stabil. Innerhalb der Inkubationszeit von 14 Tagen stieg die Anzahl der Bakterien in den Wasserproben 100–1000fach an. Baklerien des Genus Pseudomonas waren predominant. 3 von 25 Bakterienisolaten zeigten IHNV inaktivierende Wirkungen bis zu 50%. Bin Pseudo-monastamm inaktivierte das Virus bis zu 99%. Mit bakierienfrei filtriertem bzw. autoklaviertem Wasser wurden keine Virustiterreduktionen beobachtet.〈section xml:id="abs1-3"〉〈title type="main"〉RésuméInfluence tie I'eau environnante sur les infectiosités du virus de la nécrose infectieuse de I'hématopoïèse (IHNV) et du virus de la nécrose infectieuse du pancréas (IPNV)Des prélèvements d'eau faits chaque saison dans des écloseries de salmonidés au Japon ont été comparés quant à leur possibilité de réduireles titres d'infectiosité du virus de la nécrose infectieuse de l'hémalopo-ïèse (IHNV) el du virus de la nécrose infectieuse du pancréas (IPNV). En l'espace de trois jours le titre de IHNV a été réduil à 15°C à un degré en dessous de la limite de déiection á l'aide de prélèvemenis d'eau non-iraités et de prélèvements d'eau contenant des sédimenis. Une petite réduction de l'infectiosité de IPNV a été constatée dans tous les prélèvements d'eau. L'utilisalion d'eau sans bactérie, traitée par filtration ou autoclave, n'a apportée aucune reduction de l'infectiosilé des virus. Les résuliats étaient semblables avec l'eau recueillie chaque saison. Après une incubation des prélèvements, le nombre de bactéries viables a augmenté de 100 à 1000 fois. Les membres du genre Pseudomonas prédominaient dans les prélèvments d'eau et de sédiment. Les bactéries isolées de l'eau prélevée dans une écloserie de salmonidés au printemps 1984 ont été examinées quant à leur activité conlre le IHNV. 3 des 25 bactéries isolées montraient une activité anti-IHNV (réduction des plaques de plus de 50%) dans les filtrats de culture, y compris une souche de Pseudomonas montrant une activité anti-IHNV efficace (réduction des plaques 99%).

Notes: The five herpesviruses isolated from salmonid fishes were compared for their serological relatedness by serum cross-neutralization studies with polyclonal rabbit serum. The five viruses fell into two major groups. The three viruses from fishes in Japan, Oncorbyncbus mason virus (OMV), yamame tumor virus (YTV) and nerka virus (NeVTA) were closely related. They however, differed considerably from two viruses from salmonid fishes in North America, Herpesvirus salmonis (HPV) and the steelhead herpesvirus (SHV). The latter two viruses were also closely related. This study indicated that the viruses in the two countries are serologically distinct and are not a result of transfers of infected fish or eggs between continents.

Notes: Muscle Type I collagen of five teleosts was characterized with respect to its thermal stability and subunit composition. The muscle collagen exhibited a higher denaturation temperature, Td, in solution and a higher degree of proline hydroxylation, compared with skin Type I collagen of the respective species. Moreover, the Td values seemed to increase with the increasing upper limit of environmental temperature of fish habitats. The subunit composition also varied with fish species; an α1α2α3 heterotrimer existed in eel and common mackerel and an (α1)2α2 heterotrimer in saury, while (α1)2α2 and α1α2α3 heterotrimers appeared to be major and minor components, respectively, in chum salmon and carp.

Notes: The abdominal muscle tissues of giant river prawn, fleshy prawn and spiny lobster contained 2.4–2.6% collagen of the total tissue protein. Alkali-insoluble proteins were prepared from the muscle tissues by treatment with 0. 1N NaOH at 4°C and found to exhibit the amino acid composition typical of collagen. The muscle collagens, consisting of α chain-sized components, were then isolated by limited pepsin digestion and characterized by a high content of hydroxylysine and its glycoside and a low content of alanine. In addition, subcuticular membranes covering the muscle tissues were found to be comprised mainly of such an alkali-insoluble collagen.