TABLE 1.

Effect of materials added to stationary phase CM on the ability of the medium to inhibit proliferation

For proteinase K, RNase, and DNase, enzymes were added to CM for 18 h and were then removed with a 10-kDa cutoff spin filter. Organic extractions were done with an equal volume of solvent, vortexing for 20 min, and then centrifugation to separate phases. The separated phases were dried by lyophilization. Organic phases were resuspended in PBM, and the aqueous phase were resuspended in water. Approximately 30% (v/v) beads were added to CM, mixed gently for 1 h, and then removed by centrifugation. Treated CM was then incubated with wild type cells, and cell density was measured

Material added to CM	CM activity
Proteinase K	+
RNase	+
DNase	+
Hexane extraction
Organic	−
Aqueous	+
Ethyl acetate extraction
Organic	−
Aqueous	+
Dichloromethane extraction
Organic	−
Aqueous	+
Amberlite XAD-4 hydrophobic material: binding beads	−
50-X8 cation exchange beads	−
Bio-Rex 70 cation exchange beads	−
50W-X8 cation exchange beads	−
1-X8 anion exchange beads	+
1-X2 anion exchange beads	+
3-kDa cutoff spin filter
Retentate	−
Flow-through	+
2-kDa cutoff spin filter
Retentate	+
Flow-through	−