Dokdonia aurantiaca sp. nov., isolated from seaweed Zostera marina.

A non-motile, orange-coloured and rod-shaped bacterial strain, designated strain ZOW29T, was isolated from a seaweed sample collected from the South Sea, Republic of Korea. Cells were Gram-stain-negative, aerobic and non-motile. The isolate required sea salts for growth. Carotenoid pigment was produced. A phylogenetic tree based on 16S rRNA gene sequences showed that strain ZOW29T forms an evolutionary lineage within the radiation enclosing the members of the genus Dokdonia with Dokdonia diaphoros MSKK-32T, Dokdonia eikasta PMA-26Tand Dokdonia donghaensis DSW-1T (97.1 % sequence similarity each) as its nearest neighbours. The DNA-DNA relatedness values between strain ZOW29T and these four type strains were 35-48 %. The major fatty acids were iso-C15:0, iso-C17 : 0 3-OH and iso-C15 : 1 G. Strain ZOW29T contained MK-6 and phosphatidylethanolamine, an unidentified aminolipid and an unidentified polar lipid as the only isoprenoid quinone and the major polar lipids, respectively. The DNA G+C content of strain ZOW29T was 38 mol%. On the basis of polyphasic characterization, it is suggested that the isolate represents a novel species of the genus Dokdonia, for which the name Dokdonia aurantiaca sp. nov. (type strain, ZOW29T=KCTC 52956T=JCM 32295T) is proposed.

Dokdonia flava sp. nov., isolated from the seaweed Zostera marina.

A non-motile, proteorhodopsin-containing, yellow and rod-shaped bacterial strain, designated ZODW10T, was isolated from the seaweed Zostera marina collected from the West Sea, Republic of Korea. Cells were Gram-stain-negative, aerobic and non-motile. The isolate required sea salts for growth. A carotenoid pigment was produced. A phylogenetic tree based on 16S rRNA gene sequences showed that strain ZODW10T forms an evolutionary lineage within the radiation enclosing members of the genus Dokdonia with Dokdoniadiaphoros CIP 108745T (96.7 % sequence similarity) as its nearest neighbour. The major fatty acids were iso-C15:0, iso-C17 : 0 3-OH and iso-C15 : 1 G. Strain ZODW10T contained menaquinone 6 (MK-6) and phosphatidylethanolamine, an unidentified aminolipid and an unidentified polar lipid as the only isoprenoid quinone and the major polar lipids, respectively. The DNA G+C content of strain ZODW10T was 36 mol%. On the basis of the present polyphasic characterization, it is suggested that the isolate represents a novel species of the genus Dokdonia, for which the name Dokdonia flava sp. nov. (type strain, ZODW10T=KCTC 52953T=JCM 32293T) is proposed.

Zosteropenillines: Polyketides from the MarineDerived Fungus Penicillium thomii.

Twelve new polyketides, zosteropenillines A-L (1-12), together with known polyketide pallidopenilline A (13), were isolated from the ethylacetate extract of the fungus Penicillium thomii associated with the seagrass Zostera marina. Their structures were established based on spectroscopic methods. The absolute configuration of zosteropenilline A (1) as 4R, 5S, 8S, 9R, 10R, and 13S was determined by a combination of the modified Mosher's method, X-ray analysis, and NOESY data. Absolute configurations of zosteropenillines B-D (2-4) were determined by timedependent density functional theory (TD-DFT) calculations of ECD spectra. The effect of compounds 1-3, 7, 8, 10, and 11 on the viability of human drug-resistant prostate cancer cells PC3 as well as on autophagy in these cancer cells and inhibitory effects of compounds 1, 2, and 8-10 on NO production in LPS-induced RAW 264.7 murine macrophages were examined.

Algicidal and growth-inhibiting bacteria associated with seagrass and macroalgae beds in Puget Sound, WA, USA.

The algicidal and growth-inhibiting bacteria associated with seagrasses and macroalgae were characterized during the summer of 2012 and 2013 throughout Puget Sound, WA, USA. In 2012, Heterosigma akashiwo-killing bacteria were observed in concentrations of 2.8×106CFUg-1 wet in the outer organic layer (biofilm) on the common eelgrass (Zostera marina) in north Padilla Bay. Bacteria that inhibited the growth of Alexandrium tamarense were detected within the biofilm formed on the eelgrass canopy at Dumas Bay and North Bay at densities of ∼108CFUg-1 wet weight. Additionally, up to 4100CFUmL-1 of algicidal and growth-inhibiting bacteria affecting both A. tamarense and H. akashiwo were detected in seawater adjacent to seven different eelgrass beds. In 2013, H. akashiwo-killing bacteria were found on Z. marina and Ulva lactuca with the highest densities of ∼108CFUg-1 wet weight at Shallow Bay, Sucia Island. Bacteria that inhibited the growth of H. akashiwo and A. tamarense were also detected on Z. marina and Z. japonica at central Padilla Bay. Heterosigma akashiwo cysts were detected at a concentration of 3400cystsg-1 wet weight in the sediment from Westcott Bay (northern San Juan Island), a location where eelgrass disappeared in 2002. These findings provide new insights on the ecology of algicidal and growth-inhibiting bacteria, and suggest that seagrass and macroalgae provide an environment that may influence the abundance of harmful algae in this region. This work highlights the importance of protection and restoration of native seagrasses and macroalgae in nearshore environments, in particular those regions where shellfish restoration initiatives are in place to satisfy a growing demand for seafood.