Biochemical alterations in duckweed and algae induced by carrier solvents: Selection of an appropriate solvent in toxicity testing

Abstract

Carrier solvents are often used in aquatic toxicity testing for test chemicals with hydrophobic properties. However, the knowledge of solvent effects on test organisms remains limited. The present study aimed to determine the biochemical effects of the 4 common solvents methanol, ethanol, acetone, and dimethyl sulfoxide (DMSO) on 2 test species, Lemna minor and Raphidocelis subcapitata, by applying Fourier transform infrared spectroscopy (FTIR) coupled with multivariate analysis to select appropriate solvents for toxicity testing. The results showed biochemical variations associated with solvent treatments at different doses on test species. From the infrared spectra obtained, the structures of lipid membrane and protein phosphorylation in the test species were found to be sensitive to the solvents. Methanol and ethanol mainly affected the protein secondary structure, whereas acetone and DMSO primarily induced alterations in carbohydrates and proteins in the test species. The FTIR results demonstrated that methanol and ethanol showed higher biochemical alterations in the test species than acetone and DMSO, especially at the high doses (0.1 and 1% v/v). Based on the growth inhibition displayed and FTIR spectroscopy, acetone, and DMSO can be used as carrier solvents in toxicity testing when their doses are lower than 0.1% v/v. Environ Toxicol Chem 2017;36:2631-2639. © 2017 SETAC.

Effect of Organic Solvents on Microalgae Growth, Metabolism and Industrial Bioproduct Extraction: A Review

“…As a contrary, acetone, on a par ( v / v %) with DMSO, was the least toxic solvent towards Chlorella pyrenoidosa , followed by DMF, methanol and ethanol [ 48 ]. It is consistent with another report, where ethanol was stronger inhibitor of Raphidocelis subcapitata growth, than acetone or DMSO [ 77 ]. DMF, at different concentrations, was reported to inhibit or stimulate growth of various microalgae species ( H. akashiwo , I. galbana , D. tertiolecta , S. capricornutum , C. vulgaris , P. subcapitata ) [ 46 , 49 , 73 , 78 , 79 ].…”

Tolerance to allelopathic inhibition by free fatty acids in five biofuel candidate microalgae strains

“…Following methods of previous studies (DellaGreca et al, 2010;McCracken et al, 1980), a non-toxic solvent was used to ensure that the FFAs were soluble in the medium. Specifically, each fatty acid was added to a solution of DMSO; we then combined this solution of dissolved FFAs with COMBO medium such that the final concentration of DMSO was 0.2 % v/v, a concentration that does not affect algae (Hu et al, 2017), and adjusted the pH to 7.5. Each fatty acid was added in various amounts to provide a gradient of eight FFA concentrations: 0, 0.5, 1, 2, 5, 10, 20, and 50 mg L − 1 .…”

The Effect of Ultrasound on the Extraction and Functionality of Proteins from Duckweed (Lemna minor)

“…The pronounced O-H stretching (3600 to 3200 cm −1 ) region is associated with either water or carbohydrates, while the 3000 to 2800 cm −1 region, especially found in the control sample, is attributed to C-H stretching, as well as CH 2 and CH 3 from macromolecules such as fats, carbohydrates, and proteins [ 33 ]. Likewise, the 1750–1700 cm −1 region corresponds to the C=O stretching from lipids and is an indicator of their oxidation degree [ 49 ]. The bands at 1000 and 1100 cm −1 are, respectively, related to the presence of starch and carbohydrates in the sample [ 49 ], which other authors considered between 1250 and 800 cm −1 [ 33 ].…”