How Chlorella sorokiniana and its High Tolerance to Pb Might be a Potential Pb Biosorbent

Abstract

With the dynamic development of industrialization and urbanization, the entrance of heavy metals from industrial discharge, domestic sewage, and atmospheric deposition into natural water, even at low concentrations, has induced a series of potential impacts on both aquatic ecosystems and human health [1]. Being an essential part of primary productivity, algae show high sensitivity to various heavy metals such as Pb [2]. Consequently, algae serve as a testing model to evaluate the quality of freshwater and estimate the toxicity of pollutants. By now, numerous studies have illustrated that most heavy metals, including Cd, Pb, Cu, and Ni, can interfere with the photosynthesis and enzymatic metabolism of algae, which results in growth inhibition and even death. Choudhary et al. found that Pb, Cu, and Zn could generate reactive oxygen species (ROS) and attack biomolecules within the cells, further leading to irreversible adverse effects on Spirulina [3]. The analogous toxic mechanism of Cu on the green Pol. J. Environ. Stud. Vol. 26, No. 3 (2017) AbstractThe link between the acute toxicity of heavy metals on algae and the bioadsorption capacity of heavy metals by algae has seldom been reported. In the present study, an acute toxicity experiment was carried out to assess the toxic effects of Pb, Cu, and Cd for Chlorella sorokiniana, and the 96 h IC 50 values were 0.249 mg/L, 0.485 mg/L, 46.108 mg/L, and 21.00 mg/L for Cu, Cd, Pb (total), and Pb (free ion), respectively, which implied that Chlorella sorokiniana showed high tolerance to Pb compared to Cu and Cd. Pb distribution analysis indicated that 73.40% to 98.15% of free Pb ions were accumulated on the algae cell wall to avoid further intracellular accumulation, resulting in irreversible metabolic disorders. Then the adsorption capacity of Chlorella was explored. It could be found that the Langmuir model (the R 2 were 0.988 and 0.962 for living and lifelss cells, respectively) was fit to explain the adsorption equilibrium data and the q e calculated by this model were 1.54 and 2.97 mg /10 10 cells for living and lifeless cells, respectively, which was consistent with the experimental result. In the competitive adsorption, Chlorella exhibited a greater affinity for Pb with the higher removal rate compared to Cu and Ni. Therefore, the renewable Chlorella sorokiniana and its dramatic resistance to Pb may serve as a potential biosorbent for Pb in the future.

Impact of heavy metals in the microalga Chlorella sorokiniana and assessment of its potential use in cadmium bioremediation

“…This chlorophyte presents a wide range of advantages over other microalgae. Not only can C. sorokiniana tolerate a broad range of temperature (Yoshida et al, 2006), but also can grow under different adverse conditions, including wastewaters or heavy metal wastes (León-Vaz et al, 2019;Liang et al, 2017). In addition, the microalga shows a high growth rate compared to other chlorophytes explored for their use in phycoremediation, such as Chlamydomonas reinhardtii, Chlorella minutissima.…”

Roles and significance of chelating agents for potentially toxic elements (PTEs) phytoremediation in soil: A review

“…was successfully utilised for Cd remediation (Satya et al, 2020). Nevertheless, Chlorella sorokiniana has also been reported to withstand a broad range of temperatures and adverse conditions with Cd accumulation up to 11232 mg kg − 1 (Leon-Vaz et al, 2021;Liang et al, 2017;Raikova et al, 2019) (see Table 3).…”

Magnetic and electric field accelerate Phytoextraction of copper Lemna minor duckweed

“…In [ 39 ] authors investigated the extraction of heavy metal ions such as copper, nickel, cadmium, from drinking water by Chlorella sorokiniana . The processes of sorption of Pb , Cu , and Cd using green algae were studied in [ 40 ]. The microalgae Chlorella sorokiniana , Chlorella vulgaris , and S .…”