The release of alginate lyase from growing Pseudomonas syringae pathovar phaseolicola

Pseudomonas syringae pathovar phaseolicola, which produces alginate during stationary growth phase. displayed elevated extracellular alginate lyase ac tivity during both mid-exponential and late-stationary growth phases of bat ch growth. Intracellular activity remained below 22% of the total activity during exponential growth, suggesting that alginate lyase has an extracellu lar function for this organism. Extracellular enzyme activity in continuous cultures, grown in either nutrient broth or glucose-simple salts medium, p eaked at 60% of the washout rate, although nutrient broth-grown cultures di splayed more than twice the activity per gram of cell mass. These results i mply that growth rate, nutritional composition, or both initiate a release of alginate lyase from viable P. syringae pv. phaseolicola, which could mod ify its entrapping biofilm.