A novel process for enhancing oil production in algae biorefineries through bioconversion of solid by-products

Bioresour Technol. 2012 Jul:116:295-301. doi: 10.1016/j.biortech.2012.03.078. Epub 2012 Mar 30.

Abstract

This paper focuses on a novel process for adding value to algae residue. In current processes oleaginous microalgae are grown and harvested for lipid production leaving a lipid-free algae residue. The process described here includes conversion of the carbohydrate fraction into glucose prior to lipid extraction. This can be fermented to produce up to 15% additional lipids using another oleaginous microorganism. It was found that in situ enzymes can hydrolyze storage carbohydrates in the algae into glucose and that a temperature of 55 °C for about 20 h gave the best glucose yield. Up to 75% of available carbohydrates were converted to a generic fermentation feedstock containing 73 g/L glucose. The bioconversion step was found to increase the free water content by 60% and it was found that when the bioconversion was carried out prior to the extraction step, it improved the solvent extractability of lipids from the algae.

MeSH terms

  • Batch Cell Culture Techniques
  • Biofuels / analysis*
  • Biotechnology / instrumentation
  • Biotechnology / methods*
  • Carbohydrates / analysis
  • Glucose / biosynthesis
  • Kinetics
  • Lipids / analysis
  • Microalgae / growth & development
  • Microalgae / metabolism*
  • Nitrogen / analysis
  • Oils / metabolism*
  • Rheology
  • Salinity
  • Temperature
  • Viscosity

Substances

  • Biofuels
  • Carbohydrates
  • Lipids
  • Oils
  • Glucose
  • Nitrogen