title: Effects of some inorganic elements on nitrogen-fixation in blue-green algae and some ecological aspects of pollution.
abstract: Nitrogen-fixation by two species of Nostoc, one of them a lichen phycobiont, was generally stimulated by low concentrations of arsenic, cadmium, nickel, lead, palladium, and zinc. Higher concentrations (0.025 to 0.125 ppm) of arsenic, nickel, and palladium were also stimulatory; however, higher concentrations of cadmium, lead, and zinc tended to inhibit fixation. With the exception of palladium and zinc at low concentrations these six tested elements tended to inhibit nitrogen-fixation in Chlorogloea fritschii and Westiellopsis sp.
mesh_terms: D001151:Arsenic / Q000494:pharmacology*; D002104:Cadmium / Q000494:pharmacology; D000458:Cyanobacteria / Q000187:drug effects* / Q000378:metabolism; D004463:Ecology; D007854:Lead / Q000494:pharmacology; D008670:Metals / Q000494:pharmacology*; D009532:Nickel / Q000494:pharmacology; D009586:Nitrogen Fixation / Q000187:drug effects*; D010165:Palladium / Q000494:pharmacology; D012988:Soil Microbiology; D012989:Soil Pollutants; D013045:Species Specificity; D015032:Zinc / Q000494:pharmacology
chemical_list: D008670:Metals; D012989:Soil Pollutants; D002104:Cadmium; D007854:Lead; D010165:Palladium; D009532:Nickel; D015032:Zinc; D001151:Arsenic