Diazotrophs

Associative dinitrogen fixation Close interaction between a free-living diazotrophic organism and a higher plant that results in an enhanced rate of dinitrogen fixation. 

Among the five different species of Azospirillurn, only A. irakeme shows clearly pectinolytic activity on solid and in liquid medium. Moreover, this species can grow under non-diazotrophic as well as diazotrophic conditions when pectin is the sole carbon source (Khammas and Kaiser, 1991). Khammas and Kaiser (1991) analysed the pectinolytic activity of seven A. irakense isolates, and gave evidence for the presence of two types of pectinolytic enzymes. All strains tested have inducible Ca dependent pectate lyase activity. Six strains, showed also pectin methylesterase activity. So far, none of the corresponding enzymes have been purified. 

Association with nonsymbiotic diazotrophs that can contribnte to the nitrogen nutrition of... 

Perin L, L Martmez-Aguilar, R Castro-Gonzalez, P Estrada-de los Santos, T Cabellos-Avelar, HV Guedes, VM Reis, J Caballero-Mallado (2006) Diazotrophic Burkholderia species associated with field-grown maize and sugarcane. Appl Environ Microbiol 72 3103-3110. 

C. Elmerich, Molecular biology and ecology of diazotrophs associated with non-leguminous plants, Bio/Technology 2 967 (1984). 

Diazotroph An organism that derives its nitrogen for growth by fixing atmospheric N2. 

Diazotrophs Nitrogen-fixing bacteria. In the marine environment, some nitrogen fixers live as symbionts in phytoplankton, particularly diatoms. 

James, E. K. and Olivares, F. L. (1998). Infection and colonization of sugar cane and other graminaceous plants by endophytic diazotrophs. Crit. Rev. Pant Sci. 17, 77-119. 

O Neil, J.M. and Roman, M.R., Grazers and associated organisms of Trichodesmium, in Marine Pelagic Cyanobacteria Trichodesmium and other Diazotrophs, Carpenter, E.J., Ed., Kluwer Academic Press, Netherlands, 1992, 61. 

Subramaniam, A., Carpenter, E. J., Karentz, D., and Falkowski, P. G., Bio-optical properties of the marine diazotrophic cyanobacteria Trichodesmium spp. I. Absorption and photosynthetic spectra, Limnol. Oceanogr., 44, 608, 1999. 

Abou Aly and Gomaa (2002) evaluated the effect of inoculation with diazotrophs (Azotobacter chroococcum or Azospirillum brasilense) combined with either Bacillus megatherium var. phosphaticum or Glomus mosseae, in the presence of half the recommended dose of N, on the growth and yield of coriander. Inoculation with A. chroococcum or A. brasilense, combined with G. mosseae,... 

Abou Aly, H.E. and Comaa, A.O. (2002) Influence of combined inoculation with diazotrophs and phosphate solubilizers on growth, yield and volatile oil content of coriander plants (Coriandrum sativum L.). Bulletin of Faculty of Agriculture, Cairo University 53 (1), 93-113. 

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