Groth Performance And Biochemical Analysis Of The Genus Spirulina Under Different Environmental Factors

Spirulina is known to be useful to man in virtually all aspects of life including health,food and cosmetics.In the present study,we optimized biomass,chlorophyll a and protein production by varying the combination of a set of physical and chemical parameters,namely different pH levels;different nano MgO concentrations;different nitrogen,phosphorous and carbon sources;different salinity levels and different growing media.Through manipulating environmental condition of the algal growth,one can modify the biomass production.The temperature,light intensity and light/dark cycle were maintained at 30 ? ± 2,4400 Lux and 14:10 respectively throughout the study.At pH 9,the dry weight,protein and chlorophyll a contents were 7.83 ± 0.29 g/L,1.34 ± 0.12 mg/mL and 18.64 ± 0.06 ?g/mL respectively.At 0.8 mM MgO,maximum dry weight,protein and chlorophyll a contents of 3.48 ± 0.12 g/L,3.44±0.312 mg/mL and 4.80±0.12 ?g/mL respectively were obtained.By using NaNO3 as the source of nitrogen,the dry weight was 2.24 ±0.13 g/L while the protein and chlorophyll a contents were 3.24±0.30 mg/mL and 2.53±0.24 pg/mL respectively.For phosphorous,the highest contents were obtained by using K2HPO4 as the source of phosphorous.The dry weight was 2.08 ± 0.17 g/10 mL while the protein and chlorophyll a contents were 2.93 ±0.06 mg/mL and 2.52 ± 0.21?g/mL respectively.When NaHCO3 was used as the carbon source,the highest yields of dry weight(1.18 ± 0.02 g/L),protein(2.97±0.10 mg/mL)and chlorophyll a(1.15± 0.11?tg/ml)were observed.Of the growing media used,Zarrouk's medium yielded the highest biomass(3.48 ± 0.34 g/L),protein(5.26±0.41 mg/mL)and chlorophyll a contents(5.18±0.43 ?g/mL).Finally,under different salinities,the optimal dry weight(1.44 ± 0.06 g/L),protein(117.77 ± 2.00 ?g/ml)and chlorophyll a yields(1.86 ± 0.13 mg/L)were obtained at 2.5%.The highest cell growth rate(0.22 ±0.01 ?m/day)was also observed at 2.5%.The results generated by this study provide the basis for high biomass production of Spirulina which is a promising microalga endowed with many health benefits due to its high protein content.