Article

Treatment of Phaeodactylum tricornutum cells with papain facilitates lipid extraction

Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK. Electronic address: .
Journal of Biotechnology (Impact Factor: 2.87). 07/2012; 162(1):40-9. DOI: 10.1016/j.jbiotec.2012.06.033
Source: PubMed

ABSTRACT

Triacylglycerols (TAGs) from microalgae have the potential to be used for biodiesel, but several technical and economic hurdles have to be overcome. A major challenge is efficient extraction of intracellular TAGs from algae. Here we investigate the use of enzymes to deconstruct algal cell walls/membranes. We describe a rapid and simple assay that can assess the efficacy of different enzyme treatments on TAG-containing algae. By this means crude papain and bromelain were found to be effective in releasing TAGs from the diatom Phaeodactylum tricornutum, most likely because of their cysteine protease activity. Pre-treating algal biomass with crude papain enabled complete extraction of TAGs using heptane/isopropyl alcohol. Heptane as a single solvent was also effective, although complete recovery of TAG was not obtained. Economic implications of these findings are discussed, with the aim to reduce the complexity of, and energy needed in, TAG extraction.

Download full-text

Full-text

Available from: Alison G Smith
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Many algae species exhibit phenotypes that are of great interest for industrial applications. Systems biology approaches including large-scale metabolic reconstructions can guide and enhance production of biobased commodities such as fuel and human therapeutic proteins. Here we review the existing computational models of metabolism in algal species, as well as the databases and tools that are available to improve the sustainability of algae-to-energy production at industrial scales. As this field has progressed with genome sequencing, computational techniques, novel annotation tools and databases, systems biology will continue to evolve to advance the appeal of algae to a wide array of industries.
    Full-text · Article · Aug 2013 · Industrial Biotechnology
  • [Show abstract] [Hide abstract]
    ABSTRACT: One of the crucial steps in generating biofuel from algae is the separation and recovery of lipids from algal biomass. These lipids are eventually converted into liquid biofuel after processing and refining. This chapter presents an overview of extraction techniques and some of the challenges in applying these techniques to industrial-scale algal biofuel production. Lipids are well-encased inside algal cell walls. The aqueous environment of the cells makes it even more difficult to extract the lipids. Hexane extraction is presently the most economical method. Cell-disrupting methods have been attempted as complementary techniques to hexane extraction. Other methods such as super-critical fluid extraction and microwave extraction that may prove better in future are still in developmental stages. The need to dry the algal biomass is a key challenge in hexane extraction. The development of on-site smaller-capacity technologies can be another vital step to enhance industrial-scale biofuel production.
    No preview · Chapter · Jan 2014
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To improve the economic viability of microalgal biodiesel, it will be essential to optimize the productivity of fuel molecules such as triacylglyceride (TAG) within the microalgal cell. To understand some of the triggers required for the metabolic switch to TAG production, we studied the effect of the carbon supply (acetate or CO2) in Chlamydomonas reinhardtii (wild type and the starchless sta6 mutant) grown under low N availability. As expected, initial rates of TAG production were much higher when acetate was present than under strictly photosynthetic conditions, particularly for the sta6 mutant, which cannot allocate resources to starch. However, in both strains, TAG production plateaued after a few days in mixotrophic cultures, whereas under autotrophic conditions, TAG levels continued to rise. Moreover, the reduced growth of the sta6 mutant meant that the greatest productivity (measured as mg TAG liter−1 day−1) was found in the wild type growing autotrophically. Wild-type cells responded to low N by autophagy, as shown by degradation of polar (membrane) lipids and loss of photosynthetic pigments, and this was less in cells supplied with acetate. In contrast, little or no autophagy was observed in sta6 mutant cells, regardless of the carbon supply. Instead, very high levels of free fatty acids were observed in the sta6 mutant, suggesting considerable alteration in metabolism. These measurements show the importance of carbon supply and strain selection for lipid productivity. Our findings will be of use for industrial cultivation, where it will be preferable to use fast-growing wild-type strains supplied with gaseous CO2 under autotrophic conditions rather than require an exogenous supply of organic carbon.
    Preview · Article · Jan 2014 · Eukaryotic Cell
Show more

We use cookies to give you the best possible experience on ResearchGate. Read our cookies policy to learn more.