RESUMO
Previous methods of performing aquatic acetylene-reduction assays are described and several problems associated with them are discussed. A refinement of these older techniques is introduced and problems that it overcomes are also discussed. A depth profile of nitrogen fixation (C2H4 production), obtained by the refined technique, is shown for a fertilized Canadian Shield lake in the Experimental Lakes Area of northwestern Ontario.
Assuntos
Acetileno/metabolismo , Fixação de Nitrogênio , Microbiologia da Água , Azotobacter/metabolismo , Cianobactérias/metabolismo , Estudos de Avaliação como Assunto , OxirreduçãoRESUMO
Lake water samples were observed to transform [14-C]ethylene into water-soluble compounds that were undetectable by conventional acetylene reduction assay procedures. Methane oxidizing bacteria, which are known to be common in freshwaters, appeared to be responsible for this activity. As much as 28 percent of added ethylene has been observed to be transformed and this figure is probably an underestimate. It is suggested that acetylene reduction assays may not be accurately applied to samples containing methane oxidizing bacteria.
