Effects of Environmental Factors and Nutrient Availability on the Biochemical Composition of Algae for Biofuels Production: A Review

Abstract

Due to significant lipid and carbohydrate production as well as other useful properties such as high production of useful biomolecular substrates (e.g., lipids) and the ability to grow using non-potable water sources, algae are being explored as a potential high-yield feedstock for biofuels production. In both natural and engineered systems, algae can be exposed to a variety of environmental conditions that affect growth rate and cellular composition. With respect to the latter, the amount of carbon fixed in lipids and carbohydrates (e.g., starch) is highly influenced by environmental factors and nutrient availability. Understanding synergistic interactions between multiple environmental variables and nutritional factors is required to develop sustainable high productivity bioalgae systems, which are essential for commercial biofuel production. This article reviews the effects of environmental factors (i.e., temperature, light and pH) and nutrient availability (e.g., carbon, nitrogen, phosphorus, potassium, and trace metals) as well as cross-interactions on the biochemical composition of algae with a special focus on carbon fixation and partitioning of carbon from a biofuels perspective.

Protein and Lipid Content of Microalgae Scenedesmus sp. Biomass Grown in Wet Market Wastewater

“…The stress condition triggered due to the nutrient content of nitrogen and phosphorus as both a particular key for protein and lipid accumulation in microalgae cells. It is likely known that the aspects of this stress conditions are tightly linked to the available amount of nutrients; limitation of nitrogen, phosphorus, and the presence of other microorganisms [18]. Moreover, the trend value of protein and lipid were similar to the values reported by Markou et al [19] who cultivated microalgae using slaughterhouse wastewater and revealed that this phenomenon could be explained to …”

Effect of nutrients on total lipid content and fatty acids profile of Scenedesmus obliquus

“…The quantity and quality of fatty acids content as well as the entire biochemical composition varies in response to environmental conditions 8,20,24,25,38,39 . Particularly, under unfavorable environmental or stress conditions for growth, such as salinity, temperature, pH, and nutrient levels, many algae alter their lipid biosynthetic pathways towards the formation and accumulation of neutral lipids to control intracellular stress 13,40 .…”

“…PUFAs are one of the most nutritionally important and essential fatty acids because they are key nutrients in animal nutrition, and the most algae are rich in these acids 43 . Nitrogen and phosphate are two important macronutrients for phospholipids because nitrogen and phosphorus starvation shifts the lipid metabolism from membrane lipid synthesis to neutral lipid storage 39,[44][45][46] . Results of the present study also showed clearly that peaks in PUFAs are related to nitrogen and phosphorus, but its correlation with potassium and magnesium was more evident.…”

Nonlinear Relationship of Near-Bed Velocity and Growth of Riverbed Periphyton

“…An identical analysis using DM data showed similar performance to AFDM, but higher B max values. This can be explained by inorganic matter in the samples [2,54].…”