Abstrait

Production of rhodocladonic acid by immobilized cells of Cladonia miniata var. parvipes in calcium alginate

Mercedes Vivas, Laura Arribas, Lauro Xavier-Filho, Carlos Vicente

Cell aggregates of Cladonia miniata var. parvipes immobilized in calcium alginate were used to assay their ability to produce rhodocladonic acid. Immobilisates were supplied with sodium acetate or calcium acetate as precursors for phenol biosynthesis, and with ampicillin to prevent bacterial contamination. Rhodocladonic acid was actively produced during incubation of immobilized cellsmainly on calciumacetate, although cell vitality progressively decreased since long exposures of alginate to calcium ions increased the rigidity andmechanical resistance of immobilisates and produced cell plasmolysis.Ampicillin slightly improved the production of rhodocladonic acid, probably by impeding the competition of bacterial populations using acetate as a source for growth and the use of rhodocladonic acid by lowly specific redox enzymes.