Quantitative cytochemistry of glycogen in cells of pea and lupine nodule bacteria.

Using a fluorescent variation of the method of PAS reaction with auramine OO-SO2, the content of PAS-positive substance, identified on the basis of supplementary treatments of the preparations with alpha-amylase and a hot mixture of chloroform with methanol and glycogen, was determined cytofluorimetrically in cells of effective and ineffective strains of lupine and pea nodule bacteria in pure culture and under conditions of symbiosis. The largest level of glycogen was detected in bacteroid forms from lupine nodules and especially those of the pea after inoculation with ineffective strains: in comparison with the bacteroids from nodules of effective bean-Rhizobium symbiosis, it was 2.5--3.0 times as high. Cytofluorimetric determination of glycogen in cells of nodule bacteria, especially under conditions of symbiosis, can be considered as an indirect criterion of effectiveness in the preliminary selection of strains.