EurAsian Journal of BioSciences Eurasia J Biosci 14, 7101-7109 (2020) Combined effect of temperature, pH and salinity variation on the growth rate of Gloeocapsa sp. in batch culture method using Aiba and Ogawa medium Houria Bouazzara 1,2*, Farouk Benaceur 1,2, Rachid Chaibi 1,2, Ibtihel Boussebci 2, Laura Bruno 3 1 Department of Biology, Faculty of Sciences, University of Amar Telidji, 03000 Laghouat, ALGERIA 2 Laboratory of Biological and Agricultural Sciences (LSBA), Amar Thelidji university, Laghouat (UATL), 03000, ALGERIA 3 LBA-Laboratory of Biology of Algae, Dept. of Biology, University of Rome “Tor Vergata”, via Cracovia 1, 00133 Rome, ITALY *Corresponding author:
[email protected] Abstract The development of cyanobacterial cultures is influenced by many environmental factors. In this analysis, the effect of pH, salinity and temperature on the growth of Gloeocapsa sp. isolated from Tadjmout dam, Laghouat province (Algeria) was investigated. The axenic cultures were maintained in sterilized culture media (Aiba and Ogawa). pH of the media was adjusted to 6, 7 and 10 using NaOH and HCl, while salinity was adjusted to 0.1%, 0.3%, 0.6% and 0.9% by varying the amount of NaCl in the media. The effect of temperature was studied by incubating the cultures at 25˚C, and 50˚C. The growth of Gloeocapsa sp. were determined by measuring its optical density and its chlorophyll-a content. Gloeocapsa sp. preferred alkaline pH. Low pH levels adversely affect the growth of Gloeocapsa sp. and substantially decreased at pH 6 despite sustained low biomass growth at pH 6 and 7.