Applicability of water from the Bay of Gdańsk as a growth medium for mixotrophic culture of Platymonas subcordiformis.

P. subcordiformis is a potentially promising species with commercial, environmental and technological viability for industrial applications. The great potential of these microalgae lies in their fast biomass growth, pollution resistance, and compatibility with different culture media. This study aimed to determine the efficiency of P. subcordiformis biomass production in a medium prepared with water from the Bay of Gdańsk. The tested medium supported high biomass growth rates which reached 317.58 ± 42.31 mgV⁢S/dm3⋅d in the best-performing variant, with a final concentration of 3493.3 ± 465.4 mgV⁢S/dm3⋅d. In the autotrophic culture, nitrogen and phosphorus removal exceeded 98%. Amending the mixotrophic culture with glucose did not affect P. subcordiformis concentrations. However, it did significantly limit the demand for nutrients in the biomass and reduced chlorophyll a production in the cells.