Investigating the Role of GABA (gamma-aminobutyric acid) in Mitigating UV-C Light Exposure on Pseudochlorella pringsheimii Microalgae

The study aimed to investigate the impact of GABA in overcoming ultraviolet (UV)-C light exposure for 15, 30, and 45 min on Pseudochlorella pringsheimii microalgae. UV-C exposure for 45 min is the most lethal to microalgae growth. Among different combinations, the maximum biomass (0.98 g/L), pigments (chl a- 4.36 µg/mL; chl b- 2.04 µg/mL; car- 2.03 µg/mL) and lipid content (23.10%) was observed under treatment with UV-C for 15 min coupled with 2.5 mM GABA, whereas, the control groups attained 0.76 g/L of biomass, 3.45, 1.49, and 1.63 µg/mL of chl a, chl b, and car and 21.73% of lipid content. However, a decrease in biomass, lipid and pigment content was found under treatment with UV-C (no GABA). The carbohydrate content was observed to be maximum (43.88%) in microalgae cells treated with UV-C, whereas the protein content was lower in both the treatments i.e., 20.02% under UV-C and 23.46% under UV-C + GABA, as compared with that of control (33.09%). Therefore, the current study might be a new approach for enhancing the production of essential components in microalga under exposure to stress conditions.