An investigation on the effects of varying calcium concentrations on the growth and biomass of Chlorella vulgaris

Abstract

The likely effects of varying calcium concentrations on the growth and biomass production of Chlorella vulgaris algae have been studied during 2003-2004 in Guilan province, Iran. We cultured pure Chlorella vulgaris stocks in Zinder media applying seven calcium concentrations as treatments, 3 replicates for each treatment and one control. The laboratory experiments lasted 96 hours during which the temperature and light intensity were kept at 25 plus or minus 2 degrees centigrade and 3500 plus or minus 350 lux respectively. Spectrophotometer assessment of the samples at a wavelength of 750nm and visual counting at the start and end of the experiments were carried out to assess the growth and biomass of the green algae, Chlorella vulgaris. Statistical analysis of the results in SPSS software showed the effective calcium concentration to be between 0.1 to 15 mg/l while the highest growth of the algae was reached at 2.8 mg/l where as in control group (Z - 8 plus or minus N) the amounts was 9.2 mg/l. Density of the algae was 17575675 cells per milliliter of the culture medium and the absorption rate was 0.542 and algae biomass was 17676 cells per milliliter. Calcium concentrations values more than these rates can have negative effects on the growth and biomass production of the algae.