Behavior of bacterial spores in aqueous polymer two-phase systems.

Sacks, L. E. (Western Regional Research Laboratory, Albany, California), and Gordon Alderton. Behavior of bacterial spores in aqueous polymer two-phase systems. J. Bacteriol. 82:331-341. 1961.-Free spores of various species of the Bacillaceae enter the upper phase in a two-phase aqueous polymer system containing polyethylene glycol 4000 and potassium phosphate. Vegetative cells appear in the lower phase and subcellular debris is concentrated chiefly at the interface. The high selectivity of the upper phase for spores makes possible the preparation of greatly enriched concentrates of spores directly from complex natural materials, such as soil and feces. Attraction of spores for the upper phase is not diminished by autoclaving and the release of dipicolinic acid. Loss of attraction of spores for the upper phase is associated in time with the shedding of the spore coat, upon outgrowth. The partition behavior of one preparation of Bacillus megaterium showed the presence of two classes of spores.