Potential Efficiency of Green Algae Scenedesmus quadricauda in Bioremediation of Polycyclic Aromatic Hydrocarbon, Benzo[a] Pyrene(BaP)

Using algae to break down or detoxify dangerous environmental pollutants, thereby changing them into a non-hazardous condition, is known as bioremediation. Investigating the ability of the green algae Scenedesmus quadricauda (Turpin) Brébisson to break a particular polycyclic aromatic hydrocarbon (PAH) known as Benzo[a]pyrene (BaP), Under regulated laboratory circumstances and on BG11 media, the alga was cultivated and exposed to different BaP dosages (0.5, 1, and 1.5 mM). High-performance liquid chromatography (HPLC) study helped to ascertain the BaP concentration. Involving the growth curve, doubling time, photosynthetic pigments, total protein, carbohydrates, and Lipid peroxidation (Malondialdehyde MDA) levels, the research investigated various physiological and biochemical aspects. Furthermore, measured were the levels of catalase (CAT), superoxide dismutase (SOD), and reactive oxygen species (ROS). Whereas the lowest growth rate was 0.00047 on the 15th day at a concentration of 1.5 mM, the maximum growth rate (k) recorded was 0.391 on the 7th day at a concentration of 0.5 mM. Doubling time also varied from 0.00014 throughout the 15th day with 1.5 mM and from 0.1179 throughout the 7th day with 0.5 mM BaP. The results showed a definite influence of the different quantities of BaP degradation by S. quadricauda; the greatest magnitude was 40.13 throughout the 15th with 0.5 mg.L-1, while the lowest magnitude was 0 throughout the 1st day with 0.5 Mm. While the min magnitude was 0.41µg.mL-1 in 0.5 mM throughout 1st day, the max magnitude of chlorophyll-a was 18.71 (µg.mL-1) in 1.5 mM throughout the 15th day. Whereas the greatest magnitude was 9.19 µg.mL-1 in 1.5 mM throughout the 15th day, the lowest magnitude of chlorophyll b was 0.36 µg.mL-1 in 1.5 mM throughout the 1st day. While the min was 0.013 on 1st day with 1 mM, the max magnitude of ROS was 0.28 until the 15th day with 1.5 mM. With 1 mM over 1st day, the carbohydrate showed a max magnitude of 35.13 µm.mL-1, and with 1.5 mM over the 15th day, the min magnitude was 12.25(µm.mL-1). While the min protein content was 1.83 µg.mL-1 in 1.5 Mm throughout the 8th day, the max protein content was 2.14 µg.mL-1 in 1 mM throughout the 8th day; moreover, SOD fluctuated between 22.22 µg.mL-1 in 0.5 mM throughout 1st day, and 60 µg.mL-1 in as the min magnitude throughout 8th day with 1.5 mM. The results show that magnitudes of CAT fluctuated between 13.33 µg.mL-1 in the 8th and 15th mM throughout the 15th day and 73.33 µg.mL-1 in 1 mM throughout the 15th day. MDA showed the largest magnitude 59.92 µmoL.L-1 in 1.5 mM over the 1st day, while the lowest magnitude, 36.58 µmoL.L in 1 mM over the 15th day.