Bacteria sizes in a chernozem as recorded in the course of the microbial succession with the soil incubation under aerobic and anaerobic conditions

The size of the bacteria in different layers and horizons of an arable typical chernozem in the course of the microbial succession under aerobic and anaerobic conditions of incubation was studied. Bacteria with sizes of ≥0.23 and ≥0.38 μm predominated under the aerobic conditions; in the anaerobic conditions, their sizes were ≥0.17, ≥0.23, and ≥0.38 μm. Thus, under anaerobic conditions, the number of bacteria becomes greater at the expense of the increase of their fine forms. The bacterial biomass was the highest (16 μg/g soil) in the B horizon under the anaerobic conditions, probably, due to the greater number of fine bacterial forms developing in these conditions in nature. In the A horizon under the anaerobic conditions, the bacterial biomass was somewhat lower (12 μg/g soil) probably because of the high bacterial diversity there. All the soil bacteria were proved to have a size ranging within ≥0.43-0.17 μm.