The Adaptation and Modification of Rhizobium leguminosarum to Certain Adverse Conditions

A study was made of the effects of desiccation and alkalinity on the growth of the alfalfa root nodule bacteria. A similar study was reported, on the effects of gentian violet, in a previous paper (Burke & Burkey, Soil Science, 1925). In this paper it was shown that continued exposure of the organisms to the dye resulted in more resistance, which was only temporary. Later work has shown the formation of bacteroid forms when the alfalfa organism is grown on dye agar or on medium which is very acid or extremely alkaline