Data/hora: 09/06/2024 15:40:25

Provedor de dados: | 58
País: | Brazil
Título: | Nitrogenase activity of Beijerinckia derxii is preserved under adverse conditions for its growth
Autores: | Barbosa,Heloiza R.; Moretti,Marcos A.; Thuler,Daniela S.; Augusto,Elisabeth F.P.
Data: | 2002-09-01
Ano: | 2002
Palavras-chave: | Beijerinckia; Nitrogenase; Nitrogen fixation; Growth; Environmental factors.
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 µM 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.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822002000300007
Editor: | Sociedade Brasileira de Microbiologia
Relação: | 10.1590/S1517-83822002000300007
Formato: | text/html
Fonte: | Brazilian Journal of Microbiology  v.33 n.3 2002
Fonte: | info:eu-repo/semantics/openAccess