THE EVALUATION OF THE GROWTH PERFORMANCE OF A CYANOBACTERIAL ISOLATE PHORMIDIUM LUCIDUM (KÜTZİNG EX GOMONT 1892) GROWN UNDER DIFFERENT ENVIRONMENTAL CONDITIONS AND ITS USE AS A DIETARY SOURCE FOR DAPHNIA MAGNA (STRAUS 1820)

Abstract

This study presents the effect of cyanobacterium isolated from BollukLake (Konya, Türkiye) which is a saline lake on the growth performance of Daphniamagna. Isolated cyanobacteria species were identified as Phormidium lucidumaccording to its 16S rDNA sequences. The effects of different growth conditionsincluding pH (7.18, 8.15, 9.17 and 10.26), light intensity (1200, 2400, 3600 and 4800lux), temperature (10, 20, 25 and 30°C) and nitrogen concentrations (0.25, 0.5, 1.0 and1.5 g/L) on P. lucidum was studied. Effects of each environmental factor onbiochemical composition (total protein, total lipid and chlorophyll-a concentration) ofP. lucidum were also studied. The optimum growth conditions were found as pH 7.18,ambient temperature 20°C, nitrogen 0.25 g/L and light intensity 3600 lux, after a 2-week incubation period. The effects of various mixtures of the cyanobacteria andChlorella vulgaris which is a common feed for Daphniids were also evaluated for theireffects on the growth rates of D. magna. The best growth rate for D. magna wasobtained in the medium containing 100% P. lucidum at the end of the 13ᵗ ͪ day.