Nitrogenase activity of Beijerinckia derxii is preserved under adverse conditions for its growth
Braz. j. microbiol
;
33(3): 223-229, July-Sept. 2002. tab, graf
Artigo
em Inglês
| LILACS
| ID: lil-349772
RESUMO
In order to evaluate the response of Beijerinckia derxii ICB-10 to different environmental factors, growth curves and specific nitrogenase activity were studied. Tested conditions were as follows a) media with different pH values (2.5, 2.8, 4.2 and 5.7); b) medium supplemented with 230 æM aluminium sulphate; c) media with two different potassium phosphate concentrations (50 mM and 100 mM); d) shaken or still cultures; e) medium supplemented with 40 mM sodium thiosulphate. Growth curves and specific nitrogenase activity at pH 4.2 were closely similar to those for cultures at pH 5.7 (standard condition), whereas no growth occurred at pH 2.5. Changes in growth curves and/or specific nitrogenase activity were observed under the following conditions I) pH 2.8 (decrease in initial CFU number, reduction of maximum specific growth rate, reduced number of generations and stimulation of nitrogenase activity), II) presence of aluminium (early death phase), III) 50 mM PO4(3-) (reduction of maximum specific growth rate), IV) 100 mM PO4(3-) (reduction of both number of generations and maximum specific growth rate as well as early death phase), V) low O2 availability (increasing nitrogenase activity), and VI) presence of thiosulphate (reduction of maximum specific growth rate; early death phase and high stimulation of nitrogenase activity). The data obtained showed the high variability of the cell growth response to environmental factors. Nitrogenase activity was always preserved even when population growth was affected
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Assunto principal:
Técnicas In Vitro
/
Ensaios Enzimáticos Clínicos
/
Bactérias Aeróbias Gram-Negativas
/
Fixação de Nitrogênio
/
Nitrogenase
Tipo de estudo:
Estudos de avaliação
Idioma:
Inglês
Revista:
Braz. j. microbiol
Assunto da revista:
Microbiologia
Ano de publicação:
2002
Tipo de documento:
Artigo
País de afiliação:
Brasil
Instituição/País de afiliação:
Instituto de Pesquisa e Tecnologia/BR
/
Universidade de São Paulo/BR
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