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

Abstract

In this review, the effect of organic solvents on microalgae cultures from molecular to industrial scale is presented. Traditional organic solvents and solvents of new generation-ionic liquids (ILs), are considered. Alterations in microalgal cell metabolism and synthesis of target products (pigments, proteins, lipids), as a result of exposure to organic solvents, are summarized. Applications of organic solvents as a carbon source for microalgal growth and production of target molecules are discussed. Possible implementation of various industrial effluents containing organic solvents into microalgal cultivation media, is evaluated. The effect of organic solvents on extraction of target compounds from microalgae is also considered. Techniques for lipid and carotenoid extraction from viable microalgal biomass (milking methods) and dead microalgal biomass (classical methods) are depicted. Moreover, the economic survey of lipid and carotenoid extraction from microalgae biomass, by means of different techniques and solvents, is conducted.

Differential Effects of the Allelochemical Juglone on Growth of Harmful and Non-Target Freshwater Algae

“…These survival strategies stimulate the growth of green algae if allelochemical concentrations are below a certain threshold. Additionally, some organic solvents were reported to affect algal growth in both inhibiting and stimulating manners depending on different concentrations and algae [47]. Therefore, there might be a potential effect of methanol on our results.…”

Microalgal–bacterial aggregates with flue gas supply as a platform for the treatment of anaerobic digestion centrate

“…Thus, turbidity of the liquid medium was not a limiting factor for nutrients removal under the working conditions investigated since CO 2 was widely available for microalgal growth. Furthermore, the influence of the presence of ethanol in the cultivation medium on nutrients removal was also negligible under the concentrations tested (1725 ± 32 mg L −1 and 852 ± 65 mg L −1 in D1/5 and D1/10 wileyonlinelibrary.com/jctb 27 showed that, in general terms, microalgal growth is not inhibited up to ethanol concentrations of 3000 mg L −1 . In this context, air supply has been proposed as a strategy to enhance nutrients removal from centrates or other nutrient-rich effluents in microalgal-bacterial photobioreactors.…”

A review on microalgae cultivation and harvesting, and their biomass extraction processing using ionic liquids

“…Examples of such carotenoids which are widely used in pharmaceutical and food industries as nutritive supplements and coloring agents are β-carotene and astaxanthin that are mainly extracted from D. salina and Haematococcus pluvialis, respectively [115,116]. The use of 1-ethyl-3-methylimidazolium dibutylphosphate for the extraction of astaxanthin from H. pluvialis certainly aids the industry in fulfilling the need of the market via vastly improving the extraction yield at a lower energy demand and production cost which in turn makes the product to be more competitive even with the presence of artificially synthesized astaxanthin in the market [117,118]. Other microalgae metabolites of interest include tocopherols, phenolics compounds, flavonoids, and vitamins that have been previously found in microalgae extracts of different species and may be potentially extracted using ILs [119][120][121].…”