Morphological and Chemical Characteristics of a Cytophaga sp. Grown under Conditions of Magnesium Excess and Magnesium Limitation

Abstract

Cytophaga sp. NCMB 13 14 produces, especially under Mg2+-limited growth conditions, a factor that liberates a cholinesterase from plaice muscle. Just after the onset of Mg2+ limitation in a batch culture, there is a period of rapid production of the factor. Changes also occur in the morphology, ATP content and gross chemical composition of the bacteria.The protein and carbohydrate contents are raised by 60 % and 100 %, respectively, while the RNA and ATP contents are reduced to 70% and 40% of the original values. Increased amounts of carbohydrate found outside the cells after Mg2+ limitation at least partly correlated with extracellular slime observed in electron micrographs.