Nitrogen fixation associated with a hotspring green alga |
| |
Authors: | Yamada Takashi Sakaguchi Kenji |
| |
Institution: | (1) Mitsubishi-Kasei Institute of Life Sciences, 11 Minamiooya, Machida-shi, Tokyo, Japan |
| |
Abstract: | A unicellular alga which can grow in the light without a combined nitrogen source was isolated from a hot spring. The cells were almost spherical, usually 5–10 m in diameter. Absorption spectra of the watersoluble pigments and of the acetone-extracted ones revealed the existence of chlorophyll a and b and the absence of phycobilins. Thin sections examined by electron microscopy revealed an eukaryotic organization with features typical of the coccoid green algae (the Chlorococcales). Cells divided by internal cytokinesis and subsequent liberation of daughter cells from the parental wall, in a way similar to Chlorella. The alga reduced acetylene to ethylene and incorporated 15N2 into cell protoplasm when incubated in a low oxygen atmosphere. Nitrogenase activity was light-dependent, microaerophilic and thermophilic. Although the association of symbiotic nitrogen fixing prokaryotes with the cells may still be possible, any such organisms have not so far been detected.Abbreviations Used DCMU
3-(3,4-dichlorophenyl)-1,1-dimethylurea
- Chl
chlorophyll
- MBM
modified Bristol medium
- TLC
thin layer chromatography |
| |
Keywords: | Nitrogen fixation Photosynthesis Green alga Chl a and b DCMU Light and O2 dependency |
本文献已被 SpringerLink 等数据库收录! |
|