| determination of nitrogen-fixing phylotypes in lyngbya sp. and microcoleus chthonoplastes cyanobacterial mats from guerrero negro, baja california, mexico. | in many environments, biological nitrogen fixation can alleviate nitrogen limitation. the high rates of n(2) fixation often observed in cyanobacterial mats suggest that n(2) fixation may be an important source of n. in this study, organisms expressing nifh were identified in a lyngbya sp.- and two microcoleus chthonoplastes-dominated cyanobacterial mats. the pattern of nitrogenase activity was determined for the lyngbya sp. mat and a microcoleus chthonoplastes mat sampled directly in guerrero ne ... | 2004 | 15066804 |