Proposal of Litorimonas haliclonae sp. nov., isolated from a marine sponge of the genus Haliclona.

A bright-orange-pigmented, Gram-stain-negative, motile, and rod-shaped bacterium, strain MAA42T, was isolated from a marine sponge of the genus Haliclona, which is in long-time culture in a marine aquarium system at the Justus Liebig University Giessen, Germany. The strain grew at 4-34 °C (optimum 28 °C), in the presence of 0.5-9.5 % (w/v) NaCl (optimum 3.5 %) and at pH 4.5-10.0 (optimum pH 7.5). Strain MAA42T shared the highest 16S rRNA gene sequence similarity (98.1 %) with the type strain of Litorimonas taeanensis. Sequence similarities to all other closely related type strains were below 97 %. DNA-DNA hybridization of strain MAA42T with L. taeanensis DSM 22008T resulted in values of 4.7 % (reciprocal 17.7 %). Major cellular fatty acids of strain MAA42T were C18 : 1ω7c (66.2 %), C18 : 1 2-OH (17.4 %), and C18 : 0 (14.1 %). Spermidine was predominant in the polyamine pattern, and ubiquinone Q-10 was the major respiratory quinone. The polar lipid profile contained the major compounds phosphatidylglycerol, monoglycosyldiglyceride, three unidentified phospholipids, and one unidentified glycolipid. Glucuronopyranosyldiglyceride was present as a minor compound. The diagnostic diamino acid of the peptidoglycan was meso-diaminopimelic acid. The genomic DNA G+C content was 52.8 mol%. Based on the genotypic, chemotaxonomic, and phenotypic analyses, strain MAA42T represents a novel species of the genus Litorimonas, for which the name Litorimonas haliclonae is proposed. The type strain is MAA42T (=CCM 8709T=CIP 111178T=LMG 29765T).

Responses of reef building corals to microplastic exposure.

Pollution of marine environments with microplastic particles (i.e. plastic fragments <5 mm) has increased rapidly during the last decades. As these particles are mainly of terrestrial origin, coastal ecosystems such as coral reefs are particularly threatened. Recent studies revealed that microplastic ingestion can have adverse effects on marine invertebrates. However, little is known about its effects on small-polyp stony corals that are the main framework builders in coral reefs. The goal of this study is to characterise how different coral species I) respond to microplastic particles and whether the exposure might II) lead to health effects. Therefore, six small-polyp stony coral species belonging to the genera Acropora, Pocillopora, and Porites were exposed to microplastics (polyethylene, size 37-163 µm, concentration ca. 4000 particles L-1) over four weeks, and responses and effects on health were documented. The study showed that the corals responded differentially to microplastics. Cleaning mechanisms (direct interaction, mucus production) but also feeding interactions (i.e. interaction with mesenterial filaments, ingestion, and egestion) were observed. Additionally, passive contact through overgrowth was documented. In five of the six studied species, negative effects on health (i.e. bleaching and tissue necrosis) were reported. We here provide preliminary knowledge about coral-microplastic-interactions. The results call for further investigations of the effects of realistic microplastic concentrations on growth, reproduction, and survival of stony corals. This might lead to a better understanding of resilience capacities in coral reef ecosystems.

Winogradskyella haliclonae sp. nov., isolated from a marine sponge of the genus Haliclona.

A yellow-pigmented, Gram-stain-negative, motile and rod-shaped bacterium, strain M1A16T, was isolated from the internal tissue of a sponge of the genus Haliclona, which was long-term cultured in the CEMarin aquaria system at Justus Liebig University of Giessen. The strain grew well at 20-32 °C (optimum 25 °C), in the presence of 0-6 % NaCl (optimum 3 %), and at pH 5.5-9.0 (optimum pH 7.0-8.0). Phylogenetic analysis based on its 16S rRNA gene sequence placed the strain within the monophyletic cluster of the genus Winogradskyella with highest sequence similarity to Winogradskyella jejuensis CP32T (98.3 % 16S rRNA gene sequence similarity). Sequence similarities to all other type strains were 98.0 % or less. DNA-DNA hybridization of strain M1A16T with W. jejuensis CP32T resulted in hybridization values of 44.1 % (reciprocal 68.1 %). Major cellular fatty acids of strain M1A16T were iso-C15 : 1 G (18.1 %), iso-C15 : 0 (13.7 %), C16 : 1ω7c (12.9 %), iso-C17 : 0 3-OH (10.6 %) and iso-C16 : 0 3-OH (10.2 %). The overall polyamine content was very low with major components being cadaverine, spermidine and sym-homospermidine. The major quinone was menaquinone MK-6. The polar lipid profile contained predominantly phosphatidylethanolamine, two unidentified aminolipids and two unidentified lipids devoid of a detectable functional group. The genomic DNA G+C content was 32.7 mol%. Based on the phylogenetic, chemotaxonomic and phenotypic analyses, strain M1A16T represents a novel species of the genus Winogradskyella, for which the name Winogradskyella haliclonae sp. nov. is proposed. The type strain is M1A16T (=DSM 103138T=CCM 8681T=LMG 29588T=CIP 111091T).