Production of laminarinase and alginase by marine bacteria after starvation

Abstract

Laminarinase and alginase activities in marine Vibrio strains were examined during nutrient and energy starvation. Spectrophotometric assays indicated that the bacteria were able to induce the enzymes on addition of laminarin and alginate, even after periods of prolonged starvation (up to 8 months). De novo protein synthesis was responsible for enzyme induction, as shown by experiments with chloramphenicol. Mannitol partially repressed the synthesis of the enzymes. Alginate had no effect on laminarinase induction, whereas laminarin did affect the induction of alginase. Addition of peptone and yeast extract allowed more rapid induction of the enzymes. Cells grown in the presence of inducer substrates and then starved maintained measurable enzyme levels for a week or longer. The results show that the bacteria may play a role in utilisation of polymeric carbohydrates in the marine environment, even after periods of nutrient deprivation.