This step revealed significant changes, with an increase in the populations of both partners, cluster (mixed colonies) mode of colonization of the bead by the two microorganisms, increase in the size of microalgae-bacterial clusters, movement of the motile bacteria cells toward the immotile microalgae cells within solid matrix, and formation of firm structures among the bacteria, microalgae cells,

and the inert matrix that creates a biofilm. This biofilm was sufficiently strong to keep the two species attached to each other, even after eliminating the alginate support. This study showed that the common structural phenotypic interaction of Azospirillum with roots of higher plants, via fibrils and sheath material, is also formed and maintained during the interaction of this bacterium with the surface of rootless single-cell microalgae. “
“Despite their recognized contribution to species richness, the importance of rare taxa richness Selleck Ferrostatin-1 in bioassessment is unclear. This study aimed to characterize the environmental Daporinad molecular weight factors affecting the number of rare diatom taxa in western U.S. streams and rivers, and to evaluate whether this number can be used to differentiate streams with contrasting human disturbance. Three different categories of rare taxa were

used: satellite (taxa with low occurrence and low abundance), rural (taxa with high occurrence and low abundance), and urban (taxa with low occurrence and high abundance). Common taxa were included as a separate category of core taxa (taxa with high occurrence and high abundance). We analyzed 987 diatom samples collected over the period of 5 years (2000–2004) for the U.S. Environmental Protection Agency’s (EPA) Western Environmental Monitoring and Assessment Program (WEMAP). The results showed that rural taxa richness (number of rural taxa Benzatropine per site) increased along a longitudinal gradient from mountainous, fast-flowing oligotrophic streams with fewer fine substrates to large, slow-moving, nutrient-rich rivers with abundance of fine substrates. Rural

taxa richness was the only rarity metric that distinguished least disturbed (reference) sites from the most disturbed (impacted) sites, but it was significantly different only in the mountains ecoregion. Core taxa richness distinguished reference from impacted sites in the West and in each one of the three ecoregions (mountains, plains, and xeric). Our findings revealed that rural taxa richness can be used as an indicator of human disturbance in streams/rivers, especially in the mountains ecoregion, and that rarity definition is important in bioassessment. “
“International Ocean Discovery Program and Department of Geology & Geophysics, Texas A&M University, College Station, Texas, USA Dinoflagellates constitute a large proportion of the planktonic biomass from marine to freshwater environments.