The cytoplasm of vegetative cells was filled with 20 nm thick, nanocompartment-like structures of polyhedral appearance and of unknown function. BC008 was capable of complementary chromatic adaptation but did not produce

sheath pigments. When boring, it conformed well morphologically to Lagerheim’s (1886) description of Mastigocoleus testarum, one of the most common and pervasive bioerosive agents of marine carbonates. We propose strain BC008 as type strain for the species. Multigene (16S rRNA, nif  H, rbcL) phylogenies confirm that Mastigocoleus is a distinct, deeply branching genus of cyanobacteria that shares affinities and critical traits with two major taxonomic groups in the heterocystous clade (Nostocales and Stigonematales). We provide a revision of the genus and species descriptions based on our strain and findings. “
“Interactions with the bacterial community are increasingly considered to have a significant influence on marine phytoplankton populations. Here we used a click here simplified dinoflagellate-bacterium experimental culture model to conclusively demonstrate that the toxic dinoflagellate Gymnodinium catenatum H. W. Graham requires growth-stimulatory marine bacteria for postgermination

survival and growth, from the point of resting cyst germination through to vegetative growth at bloom concentrations (103 cells · mL−1). Cysts of G. catenatum were germinated and grown in unibacterial coculture with antibiotic-resistant or antibiotic-sensitive Marinobacter sp. DG879 or Brachybacterium sp., and with mixtures of these two bacteria. Addition of antibiotics to cultures grown with antibiotic-sensitive strains of bacteria resulted in death of the dinoflagellate culture, whereas cultures grown with antibiotic-resistant bacteria survived antibiotic addition and continued to grow beyond the 21 d experiment. Removal of either bacterial type from mixed-bacterial dinoflagellate cultures (using an antibiotic) resulted in cessation of dinoflagellate growth until bacterial concentration recovered to preaddition concentrations, suggesting

that the bacterial growth factors are used for dinoflagellate growth or are labile. Examination Tacrolimus (FK506) of published reports of axenic dinoflagellate culture indicate that a requirement for bacteria is not universal among dinoflagellates, but rather that species may vary in their relative reliance on, and relationship with, the bacterial community. The experimental model approach described here solves a number of inherent and logical problems plaguing studies of algal-bacterium interactions and provides a flexible and tractable tool that can be extended to examine bacterial interactions with other phytoplankton species. “
“This study was conducted to create a nutritional database on brown seaweeds and to popularize their consumption and utilization in Iran.