Process development for hydrogen production with Chlamydomonas reinhardtii based on growth and product formation kinetics (original) (raw)
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Advances in the biotechnology of hydrogen production with the microalga Chlamydomonas reinhardtii
Critical Reviews in Biotechnology, 2014
Biological hydrogen production is being evaluated for use as a fuel, since it is a promising substitute for carbonaceous fuels owing to its high conversion efficiency and high specific energy content. The basic advantages of biological hydrogen production over other ''green'' energy sources are that it does not compete for agricultural land use, and it does not pollute, as water is the only by-product of the combustion. These characteristics make hydrogen a suitable fuel for the future. Among several biotechnological approaches, photobiological hydrogen production carried out by green microalgae has been intensively investigated in recent years. A select group of photosynthetic organisms has evolved the ability to harness light energy to drive hydrogen gas production from water. Of these, the microalga Chlamydomonas reinhardtii is considered one of the most promising eukaryotic H 2 producers. In this model microorganism, light energy, H 2 O and H 2 are linked by two excellent catalysts, the photosystem 2 (PSII) and the [FeFe]-hydrogenase, in a pathway usually referred to as direct biophotolysis. This review summarizes the main advances made over the past decade as an outcome of the discovery of the sulfur-deprivation process. Both the scientific and technical barriers that need to be overcome before H 2 photoproduction can be scaled up to an industrial level are examined. Actual and theoretical limits of the efficiency of the process are also discussed. Particular emphasis is placed on algal biohydrogen production outdoors, and guidelines for an optimal photobioreactor design are suggested.
Materials Science for Energy Technologies, 2019
Hydrogen production by microalgae is a promising technology to achieve sustainable and clean energy. Among various photosynthetic microalgae able to produce hydrogen, Chlamydomonas reinhardtii is a model organism widely used to study hydrogen production. Oxygen produced by photosynthesis activity of microalgae has an inhibitory effect on both expression and activity of hydrogenases which are responsible for hydrogen production. Chlamydomonas can reach anoxia and produce hydrogen at low light intensity. Here, the effect of bacteria co-cultivation on hydrogen produced by Chlamydomonas at low light intensity was studied. Results indicated that however co-culturing Escherichia coli, Pseudomonas stutzeri and Pseudomonas putida reduced the growth of Chlamydomonas, it enhanced hydrogen production up to 24%, 46% and 32%, respectively due to higher respiration rate in the bioreactors at low light intensity. Chlamydomonas could grow properly in presence of an unknown bacterial consortium and hydrogen evolution improved up to 56% in these co-cultures.
Outdoor cultivation of Chlamydomonas reinhardtii for photobiological hydrogen production
Journal of Applied Phycology, 2011
Hydrogen photo-production by a wild type and two engineered strains of Chlamydomonas reinhardtii was investigated. Growth rate values and hydrogen yields attained as the concentration of acetate and nitrogen vary were compared. In the analysis of microalgal growth, the interaction between organic carbon (acetate) and nitrogen (nitrate) was investigated by recourse to an experimental factorial design. This analysis evidenced the existence of a statistically significant interaction between organic carbon and nitrate. Hydrogen production was attained by cultivating microalgae previously grown in mixotrophic regime with sulphur deprived medium. The influence of varying the photobioreactor headspace on hydrogen production was investigated. This analysis revealed an increase in the hydrogen produced per unit volume of culture of about one order of magnitude when the headspace volume is modified from 100 to 350 mL. This result provides valuable indications on how to design and operate photobioreactors for hydrogen production optimization and was thoroughly discussed in terms of the metabolic pathways activated by sulphur depletion.
International Journal of Bio-Science and Bio-Technology
Concerns about increasing greenhouse gas emissions are driving many countries to develop renewable energy sources. Enormous efforts are being directed towards the transition from fossil fuels to nonpolluting and renewable energy sources, one of which is bio-hydrogen. This paper explores the use of photosynthetic green microalgae Chlamydomonas reinhardtii immobilized in chitosan and co-cultured with ragi tapai to produce bio-hydrogen in a two-step process. Results show that the immobilization and presence of ragi tapai did not deter the microalgae from production of bio-hydrogen. It in fact enhanced the bio-hydrogen yield by microalgae plus it eases the process of cycling the microalgae cells between growth mode and hydrogen production mode. The maximum amount of bio-hydrogen produced by the microalgae when co-cultured with ragi tapai was 650000 ppm and the best ratio was 1:0.25 (2 g microalgae:0.5 g ragi tapai).
Photosynthesis is the ultimate natural process that supports all the biofuels generation. Photosyntetic production of hydrogen by microalgae is very attractive from the renewability point of view. Moreover, it faces several challenges: since the process itself has a low yield, a large number of considerations should be studied to optimize the hydrogen production at the lowest cost. In this work, wild-type Chlamydomonas reinhartii was grown outdoors in the Yucatan peninsula. Three different diameters of tubular photobioreactors (PBRs), two autotrophic culture media, as well as two seasons of the year were analyzed. From these variables, it was determined that the best biomass yield was during the winter season and with the Sueoka culture medium. Statistical significance differences were not found for the diameters of the PBRs. During growth, the biomass was exposed to natural light-dark cycles and at the end of the exponential phase of growth it was harvested with superabsorbent polymers. This biomass was able to produce hydrogen under anaerobic conditions in Tris-Acetate-Phosphate culture medium in indoor PBRs exposed to continuous artificial illumination. Experiments with different initial biomass concentrations in the anaerobic PBRs showed direct relationship with the hydrogen production profile.
Hydrogen production by sulfur-deprived Chlamydomonas reinhardtii under photoautotrophic conditions
International Journal of Hydrogen Energy, 2006
Thus far, all experiments leading to H-2 production by sulfur-deprived cultures of microalga have been done with photoheterotrophic cultures in the presence of acetate, which increases the cost of the H-2 produced. This study demonstrates that sustained H-2 photoproduction by a sulfur-deprived green alga, Chlamydomonas reinhardtii, is possible under strictly photoautotrophic conditions in the absence of acetate or any other
Parameters affecting the growth and hydrogen production of the green alga Chlamydomonas reinhardtii
International Journal of Hydrogen Energy, 2011
The unicellular green alga Chlamydomonas reinhardtii has the ability to photosynthetically produce molecular hydrogen under anaerobic conditions. It offers a biological route to renewable, carbon-neutral hydrogen production from sunlight and water. A better understanding of the parameters affecting the algal growth and hydrogen production kinetics is required in order to develop appropriate system parameters and design photobioreactors. It is essential to grow algal biomass efficiently and economically, and to attain high cell densities for effective hydrogen production. The nutrient requirements and process conditions that encourage the growth of dense and healthy algal cultures were explored. Anaerobic conditions were imposed by sulphur deprivation, which requires an exchange of the algal growth medium by centrifugation, dilution or ultra-filtration. A tubular-flow photobioreactor featuring a large surface-to-volume ratio and excellent light penetration through the system was commissioned. It was used to monitor and control the key parameters in the hydrogen production process, including pH, pO 2 , optical density, temperature, agitation and light intensity. Analytical techniques are being developed to characterise the reactor products, including dissolved hydrogen measurement by membrane inlet mass spectrometry. An overall H 2 yield of 3.1±0.3ml/l was measured in the tubular-flow photobioreactor. This information was used to design a novel 1l flat-plate reactor system for further detailed kinetic analysis of the hydrogen production process.
International Journal of Hydrogen Energy, 2008
Chlamydomonas reinhardtii is able to produce molecular hydrogen in a clean way. Overall H 2 release is the result of complex, interacting and transient intracellular mechanisms. To relate the dynamic coupling between culture conditions and biological responses, an original lab-scale setup has been developed. Such device enables culture conditions to be highly controlled and provides on-line mass-spectrometric measurement of gas production. A first validation was conducted with the well-known protocol of sulfur deprivation. Biochemical analysis combined with gas flow control enabled instantaneous productivities to be calculated, and kinetic evolutions of successive physiological states to be obtained. An energetic study was also conducted. A maximal energetic yield of light conversion to H 2 energy of 0.125% was achieved, far from the photosynthesis potential and usual photobioreactor efficiencies reported for biomass application (around 10%). However, the designed photobioreactor connected with data acquisition system is an innovative tool for future methodical optimization of H 2 production using photosynthetic microorganisms, integrating both bioprocess and physiological aspects.
International Journal of Hydrogen Energy, 2012
This work presents the results of a two-stage (carbon fixation and hydrogen production) experimental study for hydrogen production from microalgae using optical fiber as an internal light source. Effect of absence and presence of light on Chlamydomonas reinhardtii culture's pH shift is also evaluated. The culture pH value is a function of light intensity; the pH in the alkaline range changes from 7.5 to 9.5 in the presence and absence of optical fiber respectively. The maximum rate of hydrogen production in the presence of exogenic glucose and optical fiber is 6 mL/L cult/hour, which is higher than other reported values. This study has also revealed that the presence of light reduces the lag time for hydrogen production from 12 to 5 h. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. http://www.sciencedirect.com/science/article/pii/S0360319911028382