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 nitratesalts in the media significantly induce, aswell as alter the concentrations of commercially significant compounds like Vitamin E, phytol, etc.