Study of the changes in the growth, protein, and bioactive profile of Chlorella emersonii KJ725233 in response to sodium and ammonium nitrate

ABSTRACT

India. The alterations in its chlorophyll, protein, and antioxidant content in response to cationic stress were studied.Chlorella emersonii KJ725233 (CEK) was subjected to NaNO3 and NH4 (NO3)2 at concentrations equivalent to0.9 g/l (1×) and 1.8 g/l (2×) in the cultivation media. Qualitative alterations in the bioactives of the microalgawere identified by gas chromatography–high-resolution mass spectrometry (GC-HRMS), while the protein,chlorophyll, and antioxidant manipulations were spectrophotometrically quantified. Doubling of the proteincontent was observed when CEK was grown in 1× NH4+, whereas in 2× NH4+, chlorosis was significant. 2× NH4+also induced oxidative stress on CEK as evident from the 85.72% ± 6.72%, 197.47% ± 7.01%, 22.24% ± 1.78%,and 187.37% ± 1.88% increase in antioxidant potential, ferric reducing capacity, radical scavenging potential, andtotal phenolic content, respectively, as compsared to CEK grown in 1× Na+. These alterations as indicated fromthe GC-HRMS data correlate to the bioactive inductions/variations of/in Vitamin E, phytol, and its isomer in CEKgrown in 2× NH4+. The study thus indicates that manipulations of nitrate salts in the media significantly induce, aswell as alter the concentrations of commercially significant compounds like Vitamin E, phytol, etc.