Increased extracellular production of a cholinesterase-solubilising factor by Cytophaga NCMB 1314 during magnesium starvation

A Cytophaga sp. with the property of liberating a cholinesterase which is found in body muscle of plaice was studied. The liberation was caused by a factor of which more than 90% was found outside the bacterial cell and might possibly be associated within the slime material surrounding the bacteria. Magnesium limitation during growth of Cytophaga sp. in batch cultures resulted in an about 10-fold increase in extracellular factor activity. The increase could be immediately stopped by addition of magnesium ions or chloramphenicol to the medium. The effect of the latter might indicate that the increase in factor activity is dependent on protein synthesis under magnesium-limiting conditions.