Sensitivity and Antioxidant Response of Chlorella sp. MM3 to Used Engine Oil and Its Water Accommodated Fraction

Abstract

We exposed the microalgal strain, Chlorella sp. MM3, to unused or used engine oil, or their water accommodated fractions (WAFs) to determine growth inhibition and response of antioxidant enzymes. Oil type and oil concentration greatly affected the microalgal growth. Used oil at 0.04 % (0.4 g L(-1)) resulted in 50 % inhibition in algal growth, measured in terms of chlorophyll-a, while the corresponding concentration of unused oil was nontoxic. Similarly, used oil WAF showed significant toxicity to the algal growth at 10 % level, whereas WAF from unused oil was nontoxic even at 100 % concentration. Peroxidase enzyme in the microalga significantly increased with used oil at concentrations above 0.04 g L(-1) whereas the induction of superoxide dismutase and catalase was apparent only at 0.06 g L(-1). Activities of the antioxidant enzymes increased significantly when the microalga was exposed to 75 and 100 % WAF obtained from used oil. The used oil toxicity on microalga could be due to the presence of toxic soluble mono- and polyaromatic compounds, heavy metals, and other compounds attained by the oil during its use in the motor engines.

The green tide causative-species Ulva prolifera responding to exposure to oil and dispersant

“…Among our WAF CO treated groups, 3 mg/L crude oil stimulate the growth, pigments, carbohydrate and protein contents of U. prolifera , while 6–12 mg/L crude oil reduce these parameters. This “toxicant excitatory effect” was been confirmed in microalgae and observed in some Ulva species [ 22 , 37 ]. The reason for the growth of algae is that petroleum hydrocarbons can affect the synthesis of proteins, carbohydrate, and other biological macromolecules, and the synthesis rate directly reflects the metabolism and growth of the algae.…”

“…The activity of catalase (CAT) was measured by the amount of product combining by H 2 O 2 and ammonium molybdate. Two antioxidant enzymes were determined as described by Ramadass et al [ 22 ]. Microplate reader was used to measure the spectrophotometric value of the reagent.…”

Physiological changes and rate of resistance of Acrosiphonia arcta (Dillwyn) Gain upon exposure to diesel fuel

“…At the same time, a clear inverse correlation between the oil product concentration and the formation of free radicals and the synthesis of antioxidants was observed, i.e. the higher the petroleum concentration was, the more intensively the enzymatic activity was suppressed ( Ramadass et al., 2016 , 2017 ). The authors note the following dependence of the enzymatic system - POX ≥ SOD > CAT ( Ramadass et al., 2017 ).…”

“…SOD suppression at a diesel fuel concentration of 5 mg/l (which corresponds to our 100 MPC) was shown by other authors in experiments on Chlorella sp. (Ramadass et al, 2016(Ramadass et al, , 2017.…”