Data/hora: 14/06/2024 15:05:14

Biblioteca(s): 	Embrapa Agrobiologia; Embrapa Cerrados; Embrapa Solos.	
Data corrente: 	29/01/1996	
Data da última atualização: 	04/06/2002	
Autoria: 	VARGAS, M. A. T.	
Título: 	Effect of oxygen on N2 fixation by Spirillum lipoferum.	
Ano de publicação: 	1977	
Fonte/Imprenta: 	[S.l.]: Univeristy of Wisconsin, 1977.	
Páginas: 	69p.	
Idioma: 	Inglês	
Notas: 	Master Thesis.	
Conteúdo: 	The effect of dissolved oxygen tension (DOT) on the growth rate, growth yield, energy efficiency and cell composition of Spirillum lipoferum was evaluated in stirred batch and continuous culture at pH 6.8 and 30 oC using a growth limiting level of 0.1 electron equivalent (e eq) succinate/1 (0.83 g/1) as the C and e- donor source and N2 or NH4+ as the N source. DOT was controlled using an =2-stat with an autoclavable =2 electrode immersed in the culture, and premixed 1% and 4% =2 in N2 as the O2 supply. The apparent optimum DOT level for N2-fixing growth in batch and continuous culture, both from the standpoint of the rate of growth (minimum doubling time, td, of 4, 6 hr in b a t c h) and the efficiency of N2 fixation (26 and 28 mg N2 fixed/g succinate in batch and continuous culture, respectively), was about 0.0005 atm O2. At this optimum DOT for N2 -fixing growth, the storage organic carbon was estimated indirectly to be 5 to 26% and 2 to 14% (depending on the method of calculation of the cell dry weight as poly-B-hydroxybutyrate (PHB) for batch and continuous culture, respectively. The dissimilatory electron requirement for N2 fixation at the optimum DOT level was 33.3 and 34 e- eq succinate dissimilated/mole cell N, for batch and continuous culture, respectively. Under limiting O2 (e.g. DOT <<0.0005 atm O2), the td increased to 7.0 hr in batch culture; the storage C increased to 19 and 27 e- eq/mole cell N (about 48 and 57% PHD), whereas N2 fixation yield decreased to 18 and 15 mg N2 fixation increased........ 	
Palavras-Chave: 	FBN; Fixacao biologica de nitrogenio; NBF; Nitrogen fixing bacteria; O2; Oxigen; Spirillum lipoferum.	
Thesagro: 	Bactéria; Biologia do Solo; Fixação de Nitrogênio; Oxigênio; Solo.	
Thesaurus Nal: 	nitrogen fixation; oxygen; soil.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Cerrados (CPAC)	
Exemplares: 	CNPS - (4252-1) - ADD - TS - -- - 77011 - VAR - 1997.01475 - DIS
CPAC - (21338-1) - ADD - TS - -- - T048/77 - VAR - T048/77 - DIS
CNPAB - (25257-1) - ADD - TS - -- - 546.711 - V297e - 1990.00032 - DIS