Open AccessFactors affecting N 2 fixation by the cyanobacterium Trichodesmium sp. GBRTRLI101
Author(s) -
Fu FeiXue,
Bell P.R.F
Publication year - 2003
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1016/s0168-6496(03)00157-0
Subject(s) - trichodesmium , biology , nitrogen fixation , fixation (population genetics) , cyanobacteria , zoology , nitrogen , botany , food science , diazotroph , biochemistry , bacteria , chemistry , organic chemistry , gene , genetics
Various factors affecting N 2 fixation of a cultured strain of Trichodesmium sp. (GBRTRLI101) from the Great Barrier Reef Lagoon were investigated. The diurnal pattern of N 2 fixation demonstrated that it was primarily light‐induced although fixation continued to occur for at least 1 h in the dark in samples that had been actively fixing N 2 . N 2 fixation was dependent on the light intensity and stimulated more by white light when compared with blue, green, yellow and red light whereas rates of N 2 fixation decreased most under red light. Inorganic phosphorous concentrations in the lower range of treatments up to 1.2 μM significantly stimulated N 2 fixation and further additions promoted little or no increase in N 2 fixation. Organic phosphorous (Na‐glycerophosphate) also stimulated N 2 fixation rates. Added combined nitrogen (NH 4 + , NO 3 − , urea) of 10 μM did not inhibit N 2 fixation in short‐term studies (first generation), however it was depressed in the long‐term studies (fifth generation).