Midori Kurahashi

Iamia majanohamensis gen. nov., sp. nov., an actinobacterium isolated from sea cucumber Holothuria edulis, and proposal of Iamiaceae fam. nov.

A novel, Gram-positive bacterial strain, F12(T), was isolated from the abdominal epidermis of a sea cucumber, Holothuria edulis, collected from seawater off the coast of Japan. According to 16S rRNA gene sequence analysis, this strain represents a novel, deep-rooting lineage within the class Actinobacteria and clusters with uncultured bacteria and Acidimicrobium ferrooxidans. Compared to species with validly published names, the highest 16S rRNA gene sequence similarity (89.8 %) was to Acidimicrobium ferrooxidans DSM 10331(T). Phylogenetic analyses showed that strain F12(T) represents a distinct phylogenetic lineage related closely to the genus Acidimicrobium. Strain F12(T) contained MK-9(H(6)) as the major menaquinone, whilst 17 : 0, 17 : 1omega8c, 15 : 0 and 16 : 0 were the major cellular fatty acids. The cell-wall peptidoglycan of strain F12(T) was composed of meso-diaminopimelic acid as the diagnostic diamino acid, alanine and glutamic acid (1 : 2 : 1). The cell-wall sugars detected were rhamnose, mannose, arabinose, galactose and xylose. The G+C content of the DNA was 74.4 mol%. From the taxonomic data obtained in this study, the name Iamia majanohamensis gen. nov., sp. nov. is proposed for the isolate, with type strain F12(T) (=NBRC 102561(T)=DSM 19957(T)). The name Iamiaceae fam. nov. is also proposed for the distinct phyletic line represented by the genus Iamia.

Euzebya tangerina gen. nov., sp. nov., a deeply branching marine actinobacterium isolated from the sea cucumber Holothuria edulis, and proposal of Euzebyaceae fam. nov., Euzebyales ord. nov. and Nitriliruptoridae subclassis nov.

A tangerine-coloured, Gram-positive actinobacterial strain, designated F10(T), was isolated from the abdominal epidermis of a sea cucumber, Holothuria edulis, collected in seawater off the coast of Japan. A 16S rRNA gene sequence analysis indicated that strain F10(T) was a member of the class Actinobacteria and was most closely related to Nitriliruptor alkaliphilus ANL-iso2(T) (87.4 % sequence similarity). Phylogenetic analyses showed that strain F10(T) represented a novel, deep-rooted, and distinct phylogenetic lineage within the class Actinobacteria and clustered with N. alkaliphilus and uncultured bacteria. The organism had meso-diaminopimelic acid as the diagnostic diamino acid in the cell-wall peptidoglycan, and rhamnose and galactose as the diagnostic cell-wall sugars. Strain F10(T) contained C₁₆ :₀ω7c, C₁₆:₀ and C₁₇:₁ω8c as the major cellular fatty acids. The predominant isoprenoid quinone was MK-9 (H₄).The G+C content of the DNA was 68.3 mol%. Based on data from the current polyphasic study, it is proposed that the new marine isolate be placed in a novel genus and be considered a novel species designated Euzebya tangerina gen. nov., sp. nov. within the new family, order and subclass Euzebyaceae fam. nov., Euzebyales ord. nov. and Nitriliruptoridae subclassis nov. in the class Actinobacteria. The type strain of Euzebya tangerina is F10(T) (=NBRC 105439(T) =KCTC 19736(T)).

Sneathiella glossodoripedis sp. nov., a marine alphaproteobacterium isolated from the nudibranch Glossodoris cincta, and proposal of Sneathiellales ord. nov. and Sneathiellaceae fam. nov.

A novel marine bacterium, designated strain MKT133(T), was isolated from the foot epidermis of a nudibranch, Glossodoris cincta (Mollusca), collected in seawater off the coast of Japan at a depth of 4 m. This bacterium was Gram-negative, motile, mesophilic and strictly aerobic, with small rod-shaped cells. Colonies of the strain after 4-5 days incubation on marine agar 2216 at 30 degrees C were less than 1 mm in diameter. The strain required salt for growth and contained Q-10 as the predominant respiratory quinone, C(18 : 1) omega 7c, C(16 : 0) and C(17 : 1) as major cellular fatty acids and C(14 : 0) 3-OH as a hydroxy fatty acid. 16S rRNA gene sequence analysis showed that the isolate had highest similarity to Sneathiella chinensis, with 97.2 % sequence similarity to the type strain. Our phylogenetic analysis also revealed that this clade represents a distinct lineage and forms a deep branch with less than 90 % 16S rRNA gene sequence similarity to the members of the eight known orders within the Alphaproteobacteria. Sufficient differences exist to distinguish this strain from Sneathiella chinensis. The name Sneathiella glossodoripedis sp. nov. is proposed, with the type strain MKT133(T) (=IAM 15419(T) =KCTC 12842(T)). The novel order Sneathiellales ord. nov. and family Sneathiellaceae fam. nov. are proposed for the distinct phyletic line represented by the genus Sneathiella.

Solar Energy Storage Using Algae

Energy consumption in contemporary society continues to increase at a rapid pace, and global warming due to the resulting use of fossil fuels is growing increasingly severe. We need to search desperately for a practical source of renewable energy to replace fossil fuels. Most of the renewable energy sources available for use on earth are limited by factors such as energy from the sun or the inside of the earth, or gravitational attraction between the earth and the moon. However, tracing the origins of fossil fuels shows that they contain concentrated energy originally from the sun and inside the earth. Accordingly, production of fuel oil from microalgae is an attempt to artificially reproduce an instant version of this process. While microalgae fuel oil does emit carbon dioxide when used, it can be considered carbon neutral because the microalgae absorb carbon dioxide as they grow. Through photosynthesis of microalgae, solar energy is converted into and stored as chemical substances. While fats and oils extracted from them can be described as an energy source, they also can be used as a source of energy for human beings, fish, and shellfish—that is, as food. It is projected that in the future the world will face an increasingly severe food crisis due to causes including rapid population growth and climate change caused by global warming. The photosynthetic organisms of microalgae, not very well known until now, have the potential to make great contributions to solving both energy and food problems simultaneously.