title: Bioethanol production from carbohydrate-enriched residual biomass obtained after lipid extraction of Chlorella sp. KR-1.
abstract: The residual biomass of Chlorella sp. KR-1 obtained after lipid extraction was used for saccharification and bioethanol production. The carbohydrate was saccharified using simple enzymatic and chemical methods using Pectinex at pH 5.5 and 45°C and 0.3N HCl at 121°C for 15min with 76.9% and 98.2% yield, respectively, without any pretreatment. The residual biomass contained 49.7% carbohydrate consisting of 82.4% fermentable sugar and 17.6% non-fermentable sugar, which is valuable for bioethanol fermentation. Approximately 98.2% of the total carbohydrate was converted into monosaccharide (fermentable+non-fermentable sugar) using dilute acid saccharification. The fermentable sugar was subsequently fermented to bioethanol through separate hydrolysis and fermentation with a fermentation yield of 79.3%. Overall, 0.4g ethanol/g fermentable sugar and 0.16g ethanol/g residual biomass were produced.
authors.affiliation: Department of Chemical Engineering, Kyung Hee University, Gyeonggi-do 446-701, Republic of Korea.
authors.forename: Ok Kyung
authors.initials: OK
authors.lastname: Lee
authors.affiliation: Clean Fuel Department, Korea Institute of Energy Research, Daejeon 305-343, Republic of Korea.
authors.forename: You-Kwan
authors.initials: YK
authors.lastname: Oh
authors.affiliation: Department of Chemical Engineering, Kyung Hee University, Gyeonggi-do 446-701, Republic of Korea. Electronic address: eunylee@khu.ac.kr.
authors.forename: Eun Yeol
authors.initials: EY
authors.lastname: Lee
mesh_terms: D000143:Acids / Q000494:pharmacology; D056804:Biofuels / Q000032:analysis*; D018533:Biomass; D001709:Biotechnology / Q000379:methods*; D002241:Carbohydrates / Q000737:chemistry*; D002708:Chlorella / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008055:Lipids / Q000302:isolation & purification*; D058086:Microalgae / Q000187:drug effects / Q000378:metabolism; D013696:Temperature
chemical_list: D000143:Acids; D056804:Biofuels; D002241:Carbohydrates; D008055:Lipids; D000431:Ethanol
keywords: Bioethanol fermentation; Chlorella sp. KR-1; Residual biomass; Saccharification