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NITROGENASE AND HYDROGENASE IN CYANOPHILIC LICHENS
Author(s) -
MILLBANK J. W.
Publication year - 1982
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.1982.tb03379.x
Subject(s) - lichen , nitrogenase , nitrogen fixation , biology , botany , nitrogen , hydrogenase , chemistry , biochemistry , enzyme , organic chemistry
SUMMARY The in vivo evolution of hydrogen by three nitrogen fixing lichens, Peltigera membranacea, Peltigera polydactyla and Lobaria pulmonaria has been studied. The hydrogen evolved concomitant with nitrogen fixation was recycled by means of an uptake hydrogenase and in general the net evolution was zero or small at 5 and 15 °C. At 25 °C there was appreciable net evolution of hydrogen in the Petigera spp. but Lobaria showed no net evolution. Direct comparison of acetylene reduction and nitrogen fixation using 15 N 2 gave ratios of six and four for Peltigera and Lobaria; these figures imply a significant production of hydrogen and indicate an effective mechanism for countering energy loss under normal in vivo conditions.