No abstract

However, the inhibitory effect of SST on HCMV replication was ablated by anti-interferon-β β (IFN-β β) antibody suggesting that SST inhibits the replication of GCV-resistant HCMV through the induction of IFN-β β. These results suggest that SST is a novel compund with potential as an anti-HCMV.

Needle-like filamentous bacteria have been isolated commonly from the cultures of three marine microalgae including Chattonella marina, Heterosigma akashiwo and Tetraselmis sp. All filamentous strains showed good growth in the peptone-yeast extract medium with artificial sea water, but failed to grow in the medium with 3% NaCl. A major group of filamentous bacteria showed neither flagellar nor gliding motilities and formed whitish pink and slightly rough colonies on the agar medium. A major pig ment extracted from cells of the whitsh pink-colored filamentous strains (WP strains) was considered to be flexixanthin-like carotenoid according to its absorption spectrum. All of WP strains and one green ish orange (OG) strain among filamentous isolates had mole% of GC contents of DNA from 58.7 to 60.0%. DNA probes prepared from the representative strains of WP filamentous bacteria were hybri dized with DNAs from all of WP strains and the OG strain but not with those from other filamentous strains and Cytophaga-Flexibacter reference strains.

Four representative strains selected from algicidal filamentous bacteria isolated from shrimp aquacultural ponds and coastal seawater of Kagoshima Bay were tentatively identified as the genus Saprospira and divided into 4 taxonomic groups as described previously. The small subunit ribosomal DNA (SSU rDNA) sequences of the 4 representative strains were determined and applied to a phylogenetic analysis with the type species of the genus Saprospira (S. grandis ATCC23116 and ATCC23119). The results revealed a close relationship between the isolated strains and S. grandis which belongs to the Flexibacter-Bacteroides-Cytophaga (FBC) group. PCR products of intergenic spacer regions (IGS) between large and small subunit ribosomal RNA genes were shown to be composed of two or three fragments by agarose gel electrophoresis. Higher molecular weight fragments of PCR products for IGS included tRNA Ile and tRNA Ala genes but the similarity values of IGS sequences among test strains were less than 60%.

The sequences of small subunit ribosomal RNA gene (SSU rDNA) and pigment composition were examined for the five filamentous bacteria isolated from the unialgal cultures of marine microalgae Chattonella marina, Heterosigma akashiwo, or Tetraselmis sp. The SSU rDNA data suggested that the filamentous bacteria were clustered into the same species, which belonged to the Roseobacter group in a-proteobacteria. Sequence similarities of SSU rDNA to each of the other strains were more than 99%. The strains possessed bacteriochlorophyll a, but were different in carotenoid composition: four of the strains contained a carotenoid that was similar to spheroidenone but the other one did not.