ISSN:
1573-5036
Keywords:
Bradyrhizobium
;
hopanoids
;
nitrogen fixation
;
plant-microbe interaction
;
Rhizobium
;
squalene-hopene cyclase
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Hopanoid lipids have been discovered recently in a number of nitrogen-fixing soil bacteria and in Bradyrhizobium bacteria which fix nitrogen in association with legume plants. We report here an investigation of the hopanoid content in an additional number of soil bacteria capable of living in close association with plants. Of the strains investigated, hopanoids were discovered in phototrophic, nitrogen-fixing bacteria and in an extended number of Bradyrhizobium strains. Strains in which hopanoids so far have not been found belong to the following genera: Rhizobium, Sinorhizobium, Phyllobacterium, Agrobacterium, and Azoarcus. To address the function of hopanoids in Bradyrhizobium, we cloned the gene coding for a key enzyme of hopanoid biosynthesis, the squalene-hopene cyclase, and expressed the gene in E. coli. The recombinant enzyme catalyzed in vitro the cyclization of squalene to hopanoid derivatives.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00035063
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