An investigation on the development of P. catenata, Chlorella sp., S. bacillaris, and S. acutus in mixed cultures showed that in 7 out of 11 variants of these cultures the dominating species was that whose specific growth rate was higher in monoculture. This phenomenon was not observed in the bialgal culture of Chlorella sp. and S. bacillaris and in 3 mixed cultures which, apart from other algae, included P. catenata and S. acutus. In the latter P. catenata always dominated, its growth being much faster than in the monoculture.
BCF1 (bioconcentration factor after the one day of exposition) value of BaP [benzo(a)pyrene] in strain A-8, Chlorella vulgaris Beijerinck 1890 (Chlorella BB) was studied. The algae were cultured in a modified Ku¨hl-Lorentzen liquid medium at room temperature, under continuous illumination and stirring for 24 hours. The final average value of BCF1 equalled 2100 ± 140 for BaP initial concentrations in the range from 0.005 to 0.5 mg/cm3 in the culture medium. Statistical analysis of the results revealed independence of the bioconcentration factor from initial concentration of BaP. The BaP amount determined in the samples after the experiment differed markedly from the initial amount introduced to the mediums.