Simultaneous treatment (cell disruption and lipid extraction) of wet microalgae using hydrodynamic cavitation for enhancing the lipid yield

Biodiesel production from microalgae is one of the solution of the future energy problem, but its production cost is still high. One of the costly stages of this process is the lipid extraction process. It can be reduced by microalgae cell disruption. One of the mechanical method to cell disruption with the lowest energy requirement is hydrodynamic cavitation. This aim of this study is to evaluate the distribution coefficient and the mass transfer coefficient value of lipid extraction of Nannochloropsis sp. assisted by hydrodynamic cavitation and compare with conventional extraction. The hydrodynamic cavitation extraction was done at 34 °C, 1 atm. The conventional extraction was done at 34 °C, 1 atm with stirring speed 260 and 1000 rpm. The experimental result shows that the distribution coefficient dependent on the temperature with the values for 50, 44, 38 and 34 °C were 0.502, 0.394, 0.349, and 0.314 respectively. And it was according to Van’ Hoff equation with the values of ΔH° was 20.718 kJ/mol and ΔS° was 58.05 J/mol/K. The hydrodynamic cavitation extraction was faster than conventional. The mass transfer coefficient values for hydrodynamic cavitation, conventional 260 rpm and 1000 rpm were 7.373, 0.534 and 0.121 1/s respectively.

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Effect of different cell disruption methods on lipid yield of Schizochytrium sp.

10.22541/au.162389516.65563022/v1 ◽

2021 ◽

Author(s):

Mustafa Hac İsa ◽

Cansu Metin ◽

Ertan Ercan ◽

Yunus Alparslan

Keyword(s):

Fatty Acids ◽

Osmotic Shock ◽

Lipid Extraction ◽

Extraction Methods ◽

Cell Disruption ◽

Health Indices ◽

Lipid Yield ◽

Atherogenicity Index ◽

Total Fatty Acids ◽

Enzyme Application

In this study, it was investigated to increase the lipid yield of the microalgae Schizochytrium sp., by applying different cell disruption methods. Therefore, acid treatment with HCl, osmotic shock, enzyme applications and ultrasonic homogenizer were tried in this algae species combined with the Bligh and Dyer and Soxhlet methods as an alternative to classical lipid extraction methods. As a result of the study, the highest lipid value (21.72 ± 0.74%) was obtained in enzyme application with Bligh and Dyer method (BDE). The cell disruption processes increased the lipid yield compared to the control groups. The highest PUFA DHA was found in the range of 4.58 ± 2.44-19.25 ± 0.09%, and the highest value was observed in the BDE group. Highest SFA was palmitic acid. Effective results were observed in the Bligh and Dyer applied groups in terms of both total lipid and total fatty acids. In cell disruption methods, particularly in enzyme and HCl extraction, good results were obtained in terms of fatty acids. The highest total fatty acids and the highest lipid content were detected in the Bligh and Dyer enzyme (BDE). Enzyme applications are also advantageous because of being environmentally friendly. Lipid health indices such as n-6/n-3, PUFA/SFA, Atherogenicity index (AI), Thrombogenicity index (TI) and hypocholesterolemic/hypercholesterolemic ratios (HH) were almost favorable. With this study, an appropriate lipid extraction methods were determined to provide an economical and environmental friendly suggestion for future studies to be used in areas such as food, feed and cosmetics.

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