CULTURE OF PAVLOVA-LUTHERI (DROOP) GREEN (PRYMNESIOPHYTA) IN DILUTED WASTE-WATER

Cell concentrations in large-scale (14-1) laboratory cultures of Pavlo va lutheri in seawater enriched with a mixture of the effluents of the aerobic digestion of Macrocystis pyrifera and of cow and chicken manu res, were close to 2 x 10(6) cells mL-1, similar to those obtained wit h a conventional medium with nitrogen concentrations about one order o f magnitude higher. The biomass produced had similar protein contents which, in the case of the non-conventional medium, accounted for all t he nitrogen, including organic nitrogen, available in the medium. In 1 25-mL cultures, cell concentrations were significantly higher in the n itrogen-rich medium, showing that P. lutheri was nitrogen-limited in w aste-enriched seawater. Growth in unenriched seawater with nitrogen-ri ch and nitrogen-deficient inocula showed that P. lutheri can store eno ugh nitrogen for about five cell divisions and that it can use dissolv ed nitrogen at concentrations less-than-or-equal-to 0.05 mmol L-1.