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The purpose of this study was to develop a novel electrical retrieval method (ER method) for living sponge-associated microorganisms from marine sponges frozen at −80 °C. A −0.3-V vs. Ag/AgCl constant potential applied for 2 h at 9 °C induced the attachment of the sponge-associated microorganisms to an indium tin oxide/glass (ITO) or a gallium-doped zinc oxide/glass (GZO) working electrode. The electrically attached microorganisms from homogenized Spirastrella insignis tissues had intact cell membranes and showed intracellular dehydrogenase activity. Dead microorganisms were not attracted to the electrode when the homogenized tissues were autoclaved for 15 min at 121 °C before use. The electrically attached microorganisms included cultivable microorganisms retrieved after detachment from the electrode by application of a 9-MHz sine-wave potential. Using the ER method, we obtained 32 phyla and 72 classes of bacteria and 3 archaea of Crenarchaeota thermoprotei, Marine Group I, and Thaumarchaeota incertae sedis from marine sponges S. insignis and Callyspongia confoederata. Employment of the ER method for extraction and purification of the living microorganisms holds potential of single-cell cultivation for genome, transcriptome, proteome, and metabolome analyses of bioactive compounds producing sponge-associated microorganisms.

A novel Gram-positive-staining, strictly aerobic and heterotrophic bacterium, designated strain LL-002T, was isolated from organics- and methane-rich seafloor sediment at a depth of 100 m in Kagoshima Bay, Kagoshima, Japan. Colonies were lustreless and translucent white in colour. The temperature, pH and salt concentration ranges for growth were 10–30 °C, pH 6.0–6.5 and 0–1 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences confirmed that strain LL-002T belongs to the genus Aneurinibacillus of the family Paenibacillaceae. 16S rRNA gene sequence similarities between strain LL-002T and the type strains of species of the genus Aneurinibacillus were 92.8–95.7 %; the highest sequence identity was with the type strain of Aneurinibacillus migulanus. The DNA G+C content of strain LL-002T was 46.2 mol%. MK-7 was the predominant menaquinone. The predominant cellular fatty acids were iso-C15 : 0 and anteiso-C15 : 0, and the cell-wall peptidoglycan contained meso-diaminopimelic acid and glutamic acid, glycine and alanine in addition to muramic acid and glucosamine. The peptidoglycan type was A1γ. In DNA–DNA hybridization assays between strain LL-002T and the type strains of the other species of the genus Aneurinibacillus, the level of hybridization was 6.3–30.1 %. On the basis of its biological features and the 16S rRNA gene sequence comparison presented here, strain LL-002T is considered to represent a novel species of the genus Aneurinibacillus, for which the name Aneurinibacillus tyrosinisolvens sp. nov. is proposed; the type strain is LL-002T ( = NBRC 110097T = CECT 8536T).

Four diastereomers of tetradenolide, a cytotoxic α-pyrone isolated from Tetradenia riparia, were synthesized stereoselectively using the Z-selective Horner–Emmons reaction followed by acid catalyzed lactonization. Making comparison of the 1H and 13C NMR spectral data of the four diastereomers with those of the reported value of natural product did not lead to determine the relative stereochemistry of the natural tetradenolide. Thus detailed investigation of the spectral data of the related compounds led us to revise the structure of tetradenolide as deacetylboronolide., Article, TETRAHEDRON LETTERS. 55(30):4189-4192 (2014)

Amyloid β-protein (Aβ42) oligomerization is an early event in Alzheimer's disease (AD). Current diagnostic methods using sequence-specific antibodies against less toxic fibrillar and monomeric Aβ42 run the risk of overdiagnosis. Hence, conformation-specific antibodies against neurotoxic Aβ42 oligomers have garnered much attention for developing more accurate diagnostics. Antibody 24B3, highly specific for the toxic Aβ42 conformer that has a turn at Glu22 and Asp23, recognizes a putative Aβ42 dimer, which forms stable and neurotoxic oligomers more potently than the monomer. 24B3 significantly rescues Aβ42-induced neurotoxicity, whereas sequence-specific antibodies such as 4G8 and 82E1, which recognizes the N-terminus, do not. The ratio of toxic to total Aβ42 in the cerebrospinal fluid of AD patients is significantly higher than in control subjects as measured by sandwich ELISA using antibodies 24B3 and 82E1. Thus, 24B3 may be useful for AD diagnosis and therapy., アルツハイマー病特有のアミロイドβ立体構造に特異的な抗体の開発―より正確な診断手法への応用に期待―. 京都大学プレスリリース. 2016-07-06.

Four diastereomers of tetradenolide, a cytotoxic α-pyrone isolated from Tetradenia riparia, were synthesized stereoselectively using the Z-selective Horner–Emmons reaction followed by acid catalyzed lactonization. Making comparison of the 1H and 13C NMR spectral data of the four diastereomers with those of the reported value of natural product did not lead to determine the relative stereochemistry of the natural tetradenolide. Thus detailed investigation of the spectral data of the related compounds led us to revise the structure of tetradenolide as deacetylboronolide.

A novel Gram-stain-negative, aerobic, heterotrophic, stalked and capsulated bacterium with potential denitrification ability, designated strain TAR-002T, was isolated from deep seafloor sediment in Japan. Colonies lacked lustre, and were viscous and translucent white. The ranges of temperature, pH and salt concentration for growth were 8–30 °C, pH 6.0–10.0 and 1–3 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences confirmed that strain TAR-002T belongs to the genus Brevundimonas of the class Alphaproteobacteria . Levels of similarity between the 16S rRNA gene sequence of strain TAR-002T and those of the type strains of species of the genus Brevundimonas were 93.5–98.9 %; the most closely related species was Brevundimonas basaltis . In DNA–DNA hybridization assays between strain TAR-002T and its phylogenetic neighbours, Brevundimonas lenta DS-18T, B. basaltis J22T, Brevundimonas subvibrioides ATCC 15264T and Brevundimonas alba DSM 4736T, mean hybridization levels were 6.4–27.7 %. The G+C content of strain TAR-002T was 70.3 mol%. Q-10 was the major respiratory isoprenoid quinone. The major fatty acids were C18 : 1ω7c and C16 : 0, and the presence of 1,2-di-O-acyl-3-O-[d-glucopyranosyl-(1→4)-α-d-glucopyranuronosyl]glycerol (DGL) indicates the affiliation of strain TAR-002T with the genus Brevundimonas . On the basis of biological characteristics and 16S rRNA gene sequence comparisons, strain TAR-002T is considered to represent a novel species of the genus Brevundimonas , for which the name Brevundimonas denitrificans sp. nov. is proposed; the type strain is TAR-002T ( = NBRC 110107T = CECT 8537T).