The effects of accumulation of chromium (VI) on cell number, chlorophyll, growth rate, protein and sugar contents of Chlorella vulgaris

ABSTRACTMSc THESISTHE EFFECTS OF ACCUMULATION OF CHROMIUM (VI) ON CELLNUMBER, CHLOROPHYLL, GROWTH RATE, PROTEIN AND SUGARCONTENTS OF Chlorella vulgarisÖzge ÖZDİŞDEPARTMENT OF BIOLOGYINSTITUTE OF NATURAL AND APPLIED SCIENCESUNIVERSITY OF ÇUKUROVASupervisor: Assoc.Prof.Dr. Saadet SAYGIDEĞERYear: 2005, Pages: 101Jury : Assoc.Prof.Dr. Saadet SAYGIDEĞERProf.Dr. Cahit ERDEMAssist. Prof.Dr. Fatma ÇEVİKAccumulation of chromium (VI) in Chlorella vulgaris and the effects of chromium(VI) on bioconcentration factors (BCF), cell number, growth rate, protein, sugar,chlorophyll-a, chlorophyll-b and pH of Chlorella vulgaris were investigated over nine daysperiod at concentrations of 0.1, 1, 5, 10, 25 and 50 mg/L.The analysis of chromium (VI) accumulation, BCF, cell numbers, chlorophyll a andb and pH were determined each day, protein and sugar contents were determined at 1, 3, 6and 9 days. BCF rates were over 1 at all concentrations except 10 and 25 mg/L. Cell number,growth rate, chlorophyll-a and b, protein and sugar contents decreased under chromium (VI)exposure. The toxic effects of chromium (VI) on these processes were observed at highmedium concentrations (10, 25 and 50 mg/L) rather than at low medium concentrations. (0.1,1 and 5 mg/L)It was determined that chromium (VI) effects on physiological and biochemical of C.vulgaris were directly related with chromium (VI) accumulation by the algae and inhibitionin this process increased with increasing of chromium (VI) accumulation in the algae. pH ofmedium decreased due to chromium (VI) concentrations too.It was determined that C. vulgaris was rather sensitive to chromium (VI) and it canbe used as bioindicator to assess the effects chromium (VI) toxic in mediumKey Words: Chromium (VI), Chlorella vulgaris, algae, physiological effect, biochemicaleffect.II