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Title: Immobilized algal cells used for hydrogen production

Abstract

This paper explores the use of the photosynthetic green alga Chlamydomonas reinhardtii bound to solid support particles to produce hydrogen in a two-step cycle. Bound cells are more easily cycled between growth mode and hydrogen production mode. The data indicate that the presence of silica particles does not inhibit the growth of the algae in the sulfur rich growth media. Filtration experiments reveal that the algae effectively bind to the silica particles, as high removal efficiencies are observed. The silica particles appear to approach saturation algae at a mass-loading ratio of about 0.035. In hydrogen production mode, the bound algae perform about as well as free-floating algae in terms of cumulative hydrogen production. A full-factorial experiment is described in which algae concentration was deemed to have a significant effect on cumulative hydrogen production.

Authors:
; ;
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1344742
Report Number(s):
NREL/JA-270-42607
Journal ID: ISSN 1369-703X
DOE Contract Number:
AC36-08GO28308
Resource Type:
Journal Article
Resource Relation:
Journal Name: Biochemical Engineering Journal; Journal Volume: 37; Journal Issue: 1
Country of Publication:
United States
Language:
English
Subject:
09 BIOMASS FUELS; 59 BASIC BIOLOGICAL SCIENCES; immobilized cells; bioreactors; filtration; kinetic parameters

Citation Formats

Hahn, John J., Ghirardi, Maria L., and Jacoby, William A.. Immobilized algal cells used for hydrogen production. United States: N. p., 2007. Web. doi:10.1016/j.bej.2007.03.010.
Hahn, John J., Ghirardi, Maria L., & Jacoby, William A.. Immobilized algal cells used for hydrogen production. United States. doi:10.1016/j.bej.2007.03.010.
Hahn, John J., Ghirardi, Maria L., and Jacoby, William A.. 2007. "Immobilized algal cells used for hydrogen production". United States. doi:10.1016/j.bej.2007.03.010.
@article{osti_1344742,
title = {Immobilized algal cells used for hydrogen production},
author = {Hahn, John J. and Ghirardi, Maria L. and Jacoby, William A.},
abstractNote = {This paper explores the use of the photosynthetic green alga Chlamydomonas reinhardtii bound to solid support particles to produce hydrogen in a two-step cycle. Bound cells are more easily cycled between growth mode and hydrogen production mode. The data indicate that the presence of silica particles does not inhibit the growth of the algae in the sulfur rich growth media. Filtration experiments reveal that the algae effectively bind to the silica particles, as high removal efficiencies are observed. The silica particles appear to approach saturation algae at a mass-loading ratio of about 0.035. In hydrogen production mode, the bound algae perform about as well as free-floating algae in terms of cumulative hydrogen production. A full-factorial experiment is described in which algae concentration was deemed to have a significant effect on cumulative hydrogen production.},
doi = {10.1016/j.bej.2007.03.010},
journal = {Biochemical Engineering Journal},
number = 1,
volume = 37,
place = {United States},
year = 2007,
month =
}
  • When cells of Chlamydomonas sp. MGA 161, a marine green alga, were cultivated at a high CO[sub 2] concentration (15% CO[sub 2]) and low temperature (15[degrees]C), the growth lag time was much longer, but the starch accumulated was two times higher than under the basal conditions (5% CO[sub 2] 30[degrees]C). When the cells grown in the high-CO[sub 2]/low-temperature conditions were incubated under dark anaerobic conditions, the degradation of starch and production of hydrogen and ethanol were remarkably higher than those grown under the basal conditions. The lag time of cell growth was shortened, whereas the high capacity of starch accumulationmore » and hydrogen production was maintained, by cultivating the cells alternately every 12 h under the basal and high-CO[sub 2]/low-temperature conditions. Using this dual system, in which the cultivation was alternated between the two conditions, the total productivity was significantly improved. 12 refs., 4 figs., 2 tabs.« less
  • In this contribution, an NMR imaging study of heavy metal absorption in alginate, immobilized-cell biosorbents, and kombu (Laminaria japonica) algal biomass is presented. This method provides the good possibility of directly monitoring the time evolution of the spatial distribution of the ions in the materials. From these results, the authors demonstrate that rare earth ions are absorbed with a steep reaction front that can be described very well with a modified shrinking core model, while copper ions are absorbed with a more diffuse front.
  • Investigations were carried out using immobilized Chlorella cells to determine the diameter, compressibility, tolerance to phosphate chelation, and ability to retain algal cells during incubation of various alginate beads. These physical bead-characteristics were affected by a variety of interactive factors, including multivalent cation type (hardening agent) and cell, cation, and alginate concentration, the latter exhibiting a predominant influence. The susceptibility of alginate beads to phosphate chelation involved a complex interaction of cation type, concentration, and pH of phosphate solution. A scale of response ranging from gel swelling to gel shrinking was observed for a range of conditions. However, stable Camore » alginate beads were maintained in incubation media with a pH of 5.5 and a phosphate concentration of 5 micro M. A preliminary investigation into cell leakage from the beads illustrated the importance of maintaining a stable gel structure and limiting cell growth to reduce leakage.« less
  • A mild method for the immobilization of whole microbial cells has been developed. Cells were suspended in a solution of preformed, linear, water-soluble polyacrylamide chains, partially substituted with acylhydrazide groups. The prepolymerized backbone polymer was crosslinked, in the presence of viable cells, by stoichiometric amounts of dialdehydes such as glyoxal, glutardialdehyde, and periodate-oxidized polyvinyl alcohol. The crosslinking reaction, carried out in cold, neutral physiological conditions resulted in cells entrapped in gels with physical properties similar to those of the common polyacrylamide gels. However, cell damage generally caused by the acrylamide monomer was avoided. Resting Streptomyces clavuligerus cells, possessing a highmore » capacity for antibiotic production, were entrapped according to this procedure. These immobilized cells produced cephalosporins continuously for 96 hours with yields similar to those of free resting cells. The same cells, when immobilized by direct polymerization of acrylamide monomers, yielded significantly lower amounts of antibiotics. (Refs. 19).« less
  • A new technique for immobilizing H{sub 2}-photoproducing green algae within a thin (<400 {micro}m) alginate film has been developed. Alginate films with entrapped sulfur/phosphorus-deprived Chlamydomonas reinhardtii, strain cc124, cells demonstrate (a) higher cell density (up to 2,000 {micro}g Chl mL{sup -1} of matrix), (b) kinetics of H{sub 2} photoproduction similar to sulfur-deprived suspension cultures, (c) higher specific rates (up to 12.5 {micro}mol mg{sup -1} Chl h{sup -1}) of H{sub 2} evolution, (d) light conversion efficiencies to H{sub 2} of over 1% and (e) unexpectedly high resistance of the H{sub 2}-photoproducing system to inactivation by atmospheric O{sub 2}. The algal cells,more » entrapped in alginate and then placed in vials containing 21% O{sub 2} in the headspace, evolved up to 67% of the H{sub 2} gas produced under anaerobic conditions. The results indicate that the lower susceptibility of the immobilized algal H{sub 2}-producing system to inactivation by O{sub 2} depends on two factors: (a) the presence of acetate in the medium, which supports higher rates of respiration and (b) the capability of the alginate polymer itself to effectively separate the entrapped cells from O{sub 2} in the liquid and headspace and restrict O{sub 2} diffusion into the matrix. The strategy presented for immobilizing algal cells within thin polymeric matrices shows the potential for scale-up and possible future applications.« less