A novel characteristic of a phytoplankton as a potential source of straight-chain alkanes.

Biosynthesis of hydrocarbons is a promising approach for the production of alternative sources of energy because of the emerging need to reduce global consumption of fossil fuels. However, the suitability of biogenic hydrocarbons as fuels is limited because their range of the number of carbon atoms is small, and/or they contain unsaturated carbon bonds. Here, we report that a marine phytoplankton, Dicrateria rotunda, collected from the western Arctic Ocean, can synthesize a series of saturated hydrocarbons (n-alkanes) from C10H22 to C38H78, which are categorized as petrol (C10-C15), diesel oils (C16-C20), and fuel oils (C21-C38). The observation that these n-alkanes were also produced by ten other cultivated strains of Dicrateria collected from the Atlantic and Pacific oceans suggests that this capability is a common characteristic of Dicrateria. We also identified that the total contents of the n-alkanes in the Arctic D. rotunda strain increased under dark and nitrogen-deficient conditions. The unique characteristic of D. rotunda could contribute to the development of a new approach for the biosynthesis of n-alkanes.

Major and minor elemental compositions of streambed biofilms and its implications of riverine biogeochemical cycles.

Chemical compositions of streambed biofilms from a major river of central Japan (the Kushida River) were obtained, with data of associated sediments (fine-grained fractions < 63 µm) and dissolved components of waters, in order to provide preliminary information about biogeochemical significance of streambed biofilms. During the sampling period (July 31st to August 3rd, 2013), dissolved components of the river waters were influenced by the dam reservoir. Concentrations of NO3-, silica (as Si), SO42-, PO43- and Ca2+ decreased across the dam, whereas Fe and Mn increased across the dam, and then decreased downstream rapidly. Streambed biofilms contain significant amount of non-nutrient elements such as Al (up to 21% as Al2O3 on water and others-free basis), indicating that they are contaminated as siliciclatic (silt and clay) materials. Siliciclastic materials in the biofilms are basically compositionally similar to fine-grained (<63 µm) fractions of streambed sediments. However, some elements such as Ca, P, Mn, and Zn are markedly enriched in the biofilms. Particularly, Mn concentrations in the biofilm samples collected just below the dam reservoir are very high (∼4.0 wt %), probably due to accumulation from the discharged water. Concentrations of trace elements such as P, Cr, Cu, Zn and V appear to be controlled by amounts of Fe-oxides and/or Mn-oxides in biofilms. Numbers of factors are involved in controlling chemical compositions of streambed biofilms, including amount of contaminated siliciclastics, authigenic mineral formation, adsorption of dissolved materials and microbial metabolisms. As demonstrated by this study, systematic analyses including major elements and comparison with associated sediments and waters could reveal biogeochemistry of this complex system.

Isolation and characterization of 22 EST-SSR markers for the genus Thujopsis (Cupressaceae).

UNLABELLED: • PREMISE OF THE STUDY: Expressed sequence tag-simple sequence repeat (EST-SSR) markers were developed from Thujopsis dolabrata var. hondae (Cupressaceae) using Illumina sequencing to investigate the genetic diversity and population structure of the genus Thujopsis. • METHODS AND RESULTS: Twenty-two primer pairs were developed from ESTs of T. dolabrata var. hondae. The primers amplified di- and trinucleotide repeat-containing sequences. Polymorphisms were assessed in 81 individuals from two T. dolabrata var. hondae populations and one T. dolabrata population. The number of alleles ranged from one to 17 per locus. The observed and expected heterozygosities ranged from 0.000 to 1.000 and from 0.000 to 0.926, respectively. • CONCLUSIONS: These new EST-SSR markers will be useful in analyses of the genetic diversity and population structure of the genus Thujopsis.

Bromocriptine-induced reversible lysosomal change and reduction of prolactin and growth hormone messenger RNA in cultured GH3 cell lines.

We examined the effects of bromocriptine on the ultrastructure and on the levelsof messenger RNA (mRNA) of prolactin and growth hormone (GH) in a cultured GH3 cell line. Prolactin and GH concentrations measured by radioimmunoassay in the incubation medium as well as the cell number of the GH3 cells were significantly decreased by treatment with 10-4M bromocriptine for 24 hours. Electron microscopy of bromocriptine-treated GH3 cells demonstrated accumulation of cytoplasmic vacuoles containing cytoplasmic components including secretory granules (crinophagy) which were positive for acid phosphatase staining. The remarkable morphological changes in GH3 cells, induced by treatment with 10-4M bromocriptine for 24 hours, disappeared 48 hours after substitution with bromocriptine-free medium. An immunoelectron-microscopic study demonstrated gold particles binding with antiprolactin antibodies not only In the cytoplasm but also inside vacuoles of GH3 cells after incubation with bromocriptine for 24 hours. Treatment with 10-4M bromocriptine for 24 hours caused the reduction both of mRNAs of prolactin measured by dot-blot hybridization and the Northern-blotting method and of GH measured by the Northern-blotting method. In conclusion, bromocriptine induces a reversible lysosomal change and could inhibit gene transcription of prolactin and GH in GH3 cells.Endocr Pathol 4:28-33, 1993.