PHYSIOLOGY OF GROWTH AND CARBOXYL ESTERASE SECRETION OF A NEWLY-ISOLATED BACILLUS-THERMOGLUCOSIDASIUS STRAIN EAEC, ENRICHED ON ETHYL-ACETATE

The physiological aspects of growth and extracellular esterase activit y of a Bacillus species, isolated from an enrichment culture on ethyl acetate and identified recently as B. thermoglucosidasius strain ''EAE C'', were investigated by growing the organism in batch, fed-batch and continuous culture regarding the carbon source, bio-availability of i ron, phosphate and ammonium concentrations in the medium. Pulse experi ments in continuous culture revealed the necessity of adding complexed Fe2+ to the medium to guarantee sufficient bioavailable iron. Extrace llular esterase activity was low in complex media, only weakly induced by ethyl acetate, and very high in cultures grown on glucose and sucr ose. The major part of esterase activity was secreted into the medium in the late exponential and in the stationary phase, implying that cat abolite-repression is a regulatory mechanism for the expression of the extracellular esterase activity.