Macromolecular Response of Individual Algal Cells to Nutrient and Atrazine Mixtures within Biofilms

摘要: Pollutant effects on biofilm physiology are difficult to assess due differential susceptibility of species and difficulty separating individual for analysis. Also, measuring whole assemblage responses such as metabolism can mask species-specific responses, some may decrease others increase metabolic activity. Physiological add information compositional data, be a more sensitive indicator effect. It is difficult, however, separate biochemical analyses. Agricultural runoff often contains multiple pollutants that alter algal assemblages in receiving waters. unclear how mixtures containing potential growth stimulators inhibitors (e.g., nutrients herbicides) structure function. In research presented here, biofilms were exposed nutrients, atrazine, their mixtures, assemblage-level structural functional changes measured. Synchrotron infrared microspectroscopy (IMS) was used isolate the within cells from dominant green alga (Mougeotia sp.), diatom (Navicula cyanobacterium (Hapalosiphon sp.). At level, generally increased biovolume, decreased chlorophyll a, had no effect or ammonium uptake. Navicula strong negative response atrazine initially, but later affected by nutrients. Hapalosiphon responded positively both Mougeotia did not exhibit any trends. Generally, each similar experiencing low stress conditions, with relative protein lipid. IMS provided direct evidence natural have unique mixtures. Results suggest initial benthic community composition should influence overall impact agricultural pollutants.