Mitosis in cells invaded by root nodule bacteria.

[Root nodule bacteria on leguminous plants].

Use of potato extract broth for culturing root-nodule bacteria.

Liquid media containing potato extract and 1% of glucose or sucrose were used to culture root-nodule bacteria (rhizobia) in shaken Erlenmeyer flasks. For comparison, these bacteria were also cultured in yeast extract-mannitol broth (YEMB) as a standard medium. Proliferation of rhizobia was monitored by measuring optical densities (OD550) of the cultures and by plate counting of the viable cells...

Growth Factor Requirements of the Root Nodule Bacteria.

It is known that yeast or plant extracts markedly stimulate the growth of the root nodule organism in media of purified ingredients. An essential growth factor or superior source of nitrogen has been invoked to explain the results, but neither theory has a broad experimental basis. The results of Allyn and Baldwin (1930) suggest that the extracts may affect favorably the oxidation-reduction pot...

Quantitative Evaluation of Acidity Tolerance of Root Nodule Bacteria

Quantification of acidity tolerance in the laboratory may be the first step in rhizobial strain selection for the Amazon region. The present method evaluated rhizobia in Petri dishes with YMA medium at pH 6.5 (control) and 4.5, using scores of 1.0 (sensitive, “no visible” growth) to 4.0 (tolerant, maximum growth). Growth evaluations were done at 6, 9, 12, 15 and 18 day periods. This method perm...

The infection of clover root hairs by nodule bacteria studied by a simple glass slide technique.

SUMMARY: A simple glass slide technique has been devised for the continuous microscopical observation of growth and infection of root hairs of clover seedlings. The method involves an aseptic cultivation of seedlings on microscope slides which are partly immersed in a mineral salts medium. The roots are protected by a cover-slip. By this procedure, the root hairs of white clover inoculated with...