Comparison of Lipid Extraction from Microalgae and Soybeans with Aqueous Isopropanol

Abstract

The extraction efficiency of microalgae lipids with aqueous isopropanol (IPA) was investigated and compared with the extraction of oil from full‐fat soy flour. The effects of the type of microalgae (Scenedesmus sp. and Schizochytrium limacinum), cell rupture, and IPA concentration on the yield of oil and non‐lipid biomass were determined. The oil yield from intact cells of Scenedesmus was 86–93 % with 70, 88, or 95 % (by wt) IPA. Ultrasonic cell rupture prior to oil extraction decreased the oil yield of Scenedesmus to 74 % when extracting with 70 % IPA. The oil yield from intact cells of S. limacinum was <23 % regardless of the IPA concentration, but ruptured cells gave a 94–96 % oil yield with 88 or 95 % IPA. The different response of the two microalgae to extraction with IPA is possibly caused by differences in the cell wall structure and type and amount of polar lipids. The oil yield from soy flour with 88 and 95 % IPA was 93–95 %, which was significantly greater than yields with 50 and 70 % IPA. Cell rupture had no effect on soy flour extraction. In general, the oil yield from the ruptured cells of both microalgae and soy flour increased with increasing IPA concentration.

Triacylglyceride Production and Autophagous Responses in Chlamydomonas reinhardtii Depend on Resource Allocation and Carbon Source

“…The lower chloroform phase was dried in a solvent evaporator (45°C; GeneVac EZ-2; SP Scientific, Ipswich, United Kingdom) and resuspended in 200 l nheptane (27). To test whether lipase activity was influencing the lipid profiles, especially the free fatty acids (FFAs), a lipase inhibitor (100 l isopropanol) was added to the pelleted samples of WT-12 and sta6 mutant cultures (day 8 of 0.1N treatment in TAP) during storage at Ϫ80°C (30).…”

Assessment and comparison of the properties of biodiesel synthesized from three different types of wet microalgal biomass

“…However, it is not selective for triacylglycerols (TAG), co-extracting other molecules such as glycolipids, phospholipids, and pigments, thus explaining the high IPA yields obtained. Nevertheless, the use of aqueous IPA (70 %) has several advantages (Yao et al 2012(Yao et al , 2013, and the present study): (i) it is an attractive alternative to toxic solvents (e.g., hexane, chloroform, and methanol); (ii) being a food-grade solvent, IPA enables the use of the residual biomass in food/feed applications;(iii) it minimizes drying costs because extraction can be done directly from wet biomass; and (iv) high lipid yields obtained suggest that stirring the biomass at reflux temperature could be sufficient to extract the lipids without any physical pretreatment to induce cell lysis (e.g., sonication or microwaves). Transesterification was performed using H2SO4, methanol, and THF, and produced biodiesel samples were further distilled under vacuum to remove all non-volatile compounds.…”

Extractive production of microbial oil using hydrophobic adsorbents: A comparative study

“…The wet cell biomass, obtained as a pellet after centrifugation of the oil production broth at 8000 rpm in an ultracentrifuge at 20 • C for 15 minutes, was used for intracellular lipid extraction. The oil extraction from these wet cells was carried as per the method described by Yao et al 18 by using Propan-2-ol:chloroform in a proportion of 1:1 (v v −1 ) as extracting solvents. The nonlipid cellular material was separated by centrifugal separation, and the supernatant was distilled in a preweighed flask to assess the intracellular oil content.…”