Investigating the influence of different concentrations of sodium nitrate and sodium bicarbonate ingredients on biomass and lipids production on microalgae;(Neochloris oleoabundans)

Document Type : Research Paper

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Abstract

Carbon and nitrogen sources are considering as the essential substances for microalgae growth. In this study the effects of sodium Nitrate (NaNO3) and sodium bicarbonate (NaHCO3) on the growth rate of N. oleoabundans microalgae in BBM culture medium were investigated. In this regards, different concentrations of NaNO3  as 0, 0.5. 1.0, 2.5, 5 and 10 and NaHCO3 as 0, 0.25, 0.5, 0.75, 1.0 and 1.25 in BBM during 21 days were tested. According to the results, by application of 10 mM NaNO3 the highest number of microalgae as (84.66±0.577)× 106 cells/mL was recorded and in case of nitrogen absence no increase in cell numbers was observed (p <0.05). However, by increasing of the concentration of NaNO3, the lipid production was decreased which the highest amount of lipid was recorded as 1.32±0.27 gL-1 without nitrogen addition (p <0.05).  In case of NaHCO3, by addition of 1.25 gL-1 sodium bicarbonate the highest cell number as (96±1.00)× 106 cell/mL was recorded whereas in its absence the lowest number of (2.00±0.00)× 106 cell/mL was obtained (p <0.05). Similarly, by addition of higher amounts of NaHCo3, the lipid production was decreased as its highest amount as 0.3±0.144 gL-1 was produced at level of 0.25 gL-1 of NaHCO3 (p <0.05). Considering the positive effects of NaHCO3 on growth of N. oleoabundans on BBM, it is recommended to use it for mass production of this microalgae.

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