Bioethanol production from carbohydrate-enriched residual biomass obtained after lipid extraction of Chlorella sp. KR-1

Bioresour Technol. 2015 Nov:196:22-7. doi: 10.1016/j.biortech.2015.07.040. Epub 2015 Jul 20.

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.

Keywords: Bioethanol fermentation; Chlorella sp. KR-1; Residual biomass; Saccharification.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acids / pharmacology
  • Biofuels / analysis*
  • Biomass*
  • Biotechnology / methods*
  • Carbohydrates / chemistry*
  • Chlorella / metabolism*
  • Ethanol / metabolism*
  • Fermentation / drug effects
  • Hydrogen-Ion Concentration
  • Hydrolysis
  • Lipids / isolation & purification*
  • Microalgae / drug effects
  • Microalgae / metabolism
  • Temperature

Substances

  • Acids
  • Biofuels
  • Carbohydrates
  • Lipids
  • Ethanol