In this study, a combined approach to produce fatty acid methyl esters (FAMEs) and succinic acid from the biomass of the microalga Micractinium sp. IC-44 using ionic liquids (ILs) was presented. After 22 days of cultivation, the biomass productivity was 0.034 ± 0.001 g L-1day-1, and the lipid content was 11.5 ± 0.5%. Direct biomass transesterification using H2SO4 in the presence of IL [BMIM][HSO4] resulted in a FAME yield of 42.0 ± 4.3%, which exceeded the yields obtained after transesterification of extracted lipids (20.5 ± 3.5% using ILs and 27.1 ± 2.4% using methanol/chloroform) and direct biomass transesterification without using ILs (31.6 ± 1.7%). The residual biomass obtained after direct transesterification using ILs was subjected to acid hydrolysis (sugar yield was 81.1 ± 2.4%). The purified hydrolysate was fermented using Actinobacillus succinogenes 130Z to obtain a succinic acid yield of 0.67 g g-1 of fermentable sugars. Therefore, this study demonstrated the successful conversion of the Micractinium sp. IC-44 biomass into biodiesel and succinic acid.
Keywords: Biodiesel; Fermentation; Ionic liquid; Microalgae; Succinic acid.
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