Pontivivens ytuae sp. nov., isolated from deep sea sediment of the Mariana Trench.

A Gram-stain-negative, light pink-coloured, rod-shaped, flagellated and facultative anaerobic bacterial strain, designated MT2928T, was isolated from deep-sea sediment collected from the Mariana Trench. Growth of strain MT2928T occurred optimally at 28 °C, pH 8.0-9.0 and in the presence of 1.0-2.0 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain MT2928T belongs to the genus Pontivivens and has the highest sequence similarity to Pontivivens insulae GYSW-23T (96.6 %). Genomic analysis indicated that strain MT2928T contains a circular chromosome of 4 199 362 bp with G+C content of 67.2 mol%. The strain did not produce bacteriochlorophyll a, but produced carotenoid. The predominant respiratory quinone of MT2928T was ubiquinone-10. The polar lipids of MT2928T contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, two unidentified lipids and two unidentified phospholipids. The major fatty acids of strain MT2928T contained summed feature 8 (C18 : 1 ω7c or/and C18 : 1 ω6c), C18 : 0 and summed feature 2 (iso-C16 : 1 I and/or C14 : 0 3-OH). On the basis of phylogenetic, physiological, biochemical and other phenotypic properties, strain MT2928T represents a novel species of the genus Pontivivens, and the name Pontivivens ytuae sp. nov. is proposed with the type species MT2928T (=MCCC 1K05575T=JCM 34320T).

Psychrosphaera ytuae sp. nov., isolated from the deep-sea cold seep sediment of South China Sea.

In this study, we report a Gram-stain-negative, rod-shaped, non-pigmented, motile and aerobic bacterium named strain MTZ26T, which was isolated from deep-sea sediment sampled at a cold seep in the South China Sea. Growth of strain MTZ26T occurred at 4-40 °C (optimum, 25-30 °C), pH 6.0-10.0 (optimum, 7.0-8.0) and with 1.0-11.0 % (w/v) NaCl (optimum, 6.0-8.0 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain MTZ26T belonged to the genus Psychrosphaera and was closely related to Psychrosphaera aestuarii PSC101T (97.5 % sequence similarity) and Psychrosphaera haliotis KDW4T (97.5 %). Genomic analysis indicated that strain MTZ26T contains a circular chromosome of 3 331 814 bp with G+C content of 42.2 mol%. The predominant respiratory quinone of MTZ26T was ubiquinone-8. The polar lipids of MTZ26T contained phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminophospholipid and one unidentified phospholipid. The major fatty acids of strain MTZ26T contained C15:0, C16:0, C17:0, C17 : 1 ω8c, C10 : 0 3-OH, C11 : 0 3-OH, C15 : 1 ω8c and summed feature 8 (C18 : 1 ω7c or/and C18 : 1 ω6c). Results of phylogenetic, physiological, biochemical and morphological analyses suggested that strain MTZ26T represents a novel species of the genus Psychrosphaera, and the name Psychrosphaera ytuae sp. nov. is proposed with the type strain MTZ26T (=MCCC 1K05568T=JCM 34321T).

[Spatiotemporal variation and related affecting factors of Gloiopeltis furcata biomass and length around Xiaoheishan Island, Shandong of China].

Gloiopeltis furcata, an important economic red macroalga, has been severely depleted due to human disturbances. Taking the natural G. furcata populations around the Xiaoheishan Island of Shandong, China as test objects, this paper studied the spatiotemporal variation pattern of their biomass and length and related affecting factors. The two-way ANCOVA showed that at island scale, both the subbottom and the Baardseth index had significant effects on the G. furcata biomass and length. The steady subbottom and the high Baardseth index were beneficial to the G. furcata growth. At micerohabitat scale, wave action and tidal level had significant effects on the G. furcata biomass and length. Wave wash and moderate tidal level promoted the G. furcata growth. The one-way repeated measurements ANOVA showed there existed seasonal variation of G. furcat biomass and length. The optimal growth period of G. furcata was from March to April, with the peak values of biomass and length appeared in late spring and early summer.

Effects of MAP kinase pathway and other factors on meiosis of Urechis unicinctus eggs.

The eggs of Urechis unicinctus Von Drasche, an echiuroid, are arrested at P-I stage in meiosis. The meiosis is reinitiated by fertilization. Immunoblotting analysis using anti-ERK2 and anti-phospho-MAPK antibodies revealed a 44 kDa MAP kinase species that was constantly expressed in U. unicinctus eggs, quickly phosphorylated after fertilization, and dephosphorylated slowly before the completion of meiosis I. Phosphorylation of the protein was not depressed by protein synthesis inhibitor Cycloheximide (CHX), but was depressed by the MEK1 inhibitor PD98059. Under PD98059 treatment, polar body extrusion was suppressed and the function of centrosome and spindle was abnormal though GVBD was not affected, indicating that MAP kinase cascade was important for meiotic division of U. unicinctus eggs. Other discovery includes: A23187 and OA could parthenogenetically activate U. unicinctus eggs and phosphorylated 44 kDa MAP kinase species, indicating that the effect of fertilization on reinitiating meiosis and phosphorylation of 44 kDa MAP kinase specie is mediated by raising intracellular free calcium and by phosphorylation of some proteins, and that phosphotase(s) sensitive to OA is responsible for arresting U. unicinctus eggs in prophase I. diC8, an activator of PKC, accelerated the process of U. unicinctus egg meiotic division after fertilization and accelerated the dephosphorylation of 44 kDa MAP kinase specie, which implied that the acceleration effect of PKC on meiotic division was mediated by inactivation of MAP kinase cascade. Elevating cAMP/PKA level in U. unicinctus eggs had no effect on meiotic division of the eggs.