Indigenous microalgae strains characterization for a sustainable biodiesel production

Microalgae are considered to be a promising group of organisms for fuel production, waste processing, pharmaceutical applications, and as a source of food components. Unicellular algae are worth being considered because of their capacity to produce comparatively large amounts of lipids, proteins, and vitamins while requiring little room for growth. They can also grow on waste and fix CO2 and nitrogen compounds. However, production costs limit the industrial use of microalgae to the most profitable applications including micronutrient production and fish farming. Therefore, novel microalgae based technologies require an increase of the production efficiencies or values. Here we review the recent studies focused on getting strains with novel characteristics or cultivating techniques that improve production's robustness or efficiency and categorize these findings according to the fundamental factors that determine microalgae growth. Improvements of light and nutrient delivery, as well as other aspects of photobioreactor design, have shown the highest average increase in productivity. Other methods, such as an improvement of phosphorus or CO2 fixation and temperature adaptation have been found to be less effective. Furthermore, interactions with particular bacteria may promote the growth of microalgae, although bacterial and grazer contaminations must be managed to avoid culture failure. The competitiveness of the algal products will increase if these discoveries are applied to industrial settings.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Recent advances and fundamentals of microalgae cultivation technology

Rozenberg,

Sorokin,

Mukhambetova

et al. 2024

“…[8,11] Selecting fast-growing Thraustochytrid species and implementing efficient downstream processing are key factors for unlocking the potential of this oleaginous protist for economical biodiesel production. [12][13][14] While extensive research has been conducted to optimize lipid and DHA production from Thraustochytrids, there is a lack of information regarding downstream processing for biodiesel and DHA purification from Thraustochytrid biomass. [5,11,12] Downstream processing encompasses various steps, including harvesting, drying, oil extraction, transesterification, oil bleaching, degumming, deodorization and purification, utilizing techniques like fractional distillation, urea crystallization, and chromatography.…”

Section: Introductionmentioning

confidence: 99%

Extraction, separation and purification of fatty acid ethyl esters for biodiesel and DHA from Thraustochytrid biomass

Singh,

Rani,

Sharma

et al. 2023

A novel approach for in situ transesterification, extraction, separation, and purification of fatty acid ethyl esters (FAEE) for biodiesel and docosahexaenoic acid (DHA) from Thraustochytrid biomass has been developed. The downstream processing of Thraustochytrids oil necessitates optimization, considering the higher content of polyunsaturated fatty acids (PUFA). While two‐step methods are commonly employed for extracting and transesterifying oil from oleaginous microbes, this may result in oxidation/epoxidation of omega‐3 oil due to prolonged exposure to heat and oxygen. To address this issue, a rapid single‐step method was devised for in situ transesterification of Thraustochytrid oil. Through further process optimization, a 50% reduction in solvent requirement was achieved without significantly impacting fatty acid recovery or composition. Scale‐up studies in a 4 L reactor demonstrated complete FAEE recovery (99.98% of total oil) from biomass, concurrently enhancing DHA yield from 16% to nearly 22%. The decolorization of FAEE oil with fuller's earth effectively removed impurities such as pigments, secondary metabolites, and waxes, resulting in a clear, shiny appearance. High‐performance liquid chromatography (HPLC) analysis indicated that the eluted DHA was over 94.5% pure, as corroborated by GC‐FID analysis.

Bicarbonate concentration influences carbon utilization rates and biochemical profiles of freshwater and marine microalgae

Kusi,

McGee,

Tabraiz

et al. 2024

Selecting the optimal microalgal strain for carbon capture and biomass production is crucial for ensuring the commercial viability of microalgae‐based biorefinery processes. This study aimed to evaluate the impact of varying bicarbonate concentrations on the growth rates, inorganic carbon (IC) utilization, and biochemical composition of three freshwater and two marine microalgal species. Parachlorella kessleri, Vischeria cf. stellata, and Porphyridium purpureum achieved the highest carbon removal efficiency (>85%) and biomass production at 6 g L−1 sodium bicarbonate (NaHCO3), while Phaeodactylum tricornutum showed optimal performance at 1 g L−1 NaHCO3. The growth and carbon removal rate of Scenedesmus quadricauda increased with increasing NaHCO3 concentrations, although its highest carbon removal efficiency (∼70%) was lower than the other species. Varying NaHCO3 levels significantly impacted the biochemical composition of P. kessleri, S. quadricauda, and P. purpureum but did not affect the composition of the remaining species. The fatty acid profiles of the microalgae were dominated by C16 and C18 fatty acids, with P. purpureum and P. tricornutum yielding relatively high polyunsaturated fatty acid content ranging between 14% and 30%. Furthermore, bicarbonate concentration had a species‐specific effect on the fatty acid and chlorophyll‐a content. This study demonstrates the potential of bicarbonate as an effective IC source for microalgal cultivation, highlighting its ability to select microalgal species for various applications based on their carbon capture efficiency and biochemical composition.