Table 1. Determination of effective antibiotic concentrations.

Antibiotic	Salt concentration	Antibiotic concentration (μg/ml)	Results		Ind. Repl.
			3 Weeks	5 Weeks
Blasticidin-S	1/2	2	Lawn	Lawn	6
	1/2	4, 6	Scattered	Scattered	6
	1/2	8, 10	No	No	6
	1/4	0.5, 1, 1.5, 2, 2.5	Lawn	Lawn	10
	1/4	3	Scattered	Scattered	10
	1/4	3.5	No	No	4
	1/4	4	No	No	24
	1/4	6	No	No	2
Tunicamycin	1/2	0.075, 0.15, 0.3, 0.6	Lawn	Lawn	1
	1/2	1.25, 2.5	Scattered	Scattered	1
	1/2	5, 10	No	Scattered	6
	1/4	5	No	No	6
	1/4	10	No	No	2
Voriconazole	1/2	0.4, 0.7, 1.1, 3.5, 7, 10.5, 35, 70, 105	Lawn	Lawn	1

Note:

2.5 × 10⁷ P. tricornutum cells were plated on each agar plate containing different concentrations of antibiotics. Tunicamycin and blasticidin-S were tested both on 50% and 25% sea salinity plates. Growth was checked after 3 and 5 weeks of incubation. “Ind. repl.” = independent replicates, “no” = no growth, “scattered” = growth in single colonies, “lawn” = lawn growth.