Artificial leaf device for hydrogen generation from immobilised C. reinhardtii microalgae

Abstract

We have engineered a hydrogen generating device replicating the function of a leaf undergoing photosynthesis based on fabric-immobilized microalgae culture with controlled perfusion with nutrients and collection of hydrogen through parallel microchannel networks.

Fabrication of living soft matter by symbiotic growth of unicellular microorganisms

“…The immobilisation of the microalgae was done in real time along with the bacterial cellulose production. Since the microalgae C. reinhardtii have the ability to produce hydrogen under nutrient deprived conditions, such living soft matter may have advantages like improved hydrogen production 13 and various other metabolite extractions. In the past, microalgae C. reinhardtii (cc124 strain) were immobilised in the alginate gel in order to increase their hydrogen production efficiency compared to suspension culture.…”

“…In the past, microalgae C. reinhardtii (cc124 strain) were immobilised in the alginate gel in order to increase their hydrogen production efficiency compared to suspension culture. 13 The developed microalgae immobilisation procedure can be used to produce natural microalgae biofilms to be potentially integrated in the artificial leaf devices. 13 The described approach of combining unicellular microorganisms working in symbiosis by passing metabolites to each other can lead to the development of other symbiotic pairs, where one type of cells builds the extracellular matrix in which the other type of cells integrates and provides essential metabolites.…”

“…12 In our case, the immobilisation of the microalgae was done in real time during the production of the bacterial cellulose gel along with a symbiotic relationship with the acetobacter which results in the growth and proliferation of the living biomaterial. It has been previously reported that the microalgae C. reinhardtii have the ability to produce biohydrogen in suspension culture as well as immobilised culture with the latter found to be more efficient, 13 hence the living soft matter may have advantages like improved hydrogen production from immobilised culture and various other metabolite extractions.…”

Microalgal hydrogen production research

“…Entrapment of C. reinhardtii in alginate films was proposed to be a useful method in the screening of transformants for the H 2 -production properties of the different lines [86]. In this vein, Das et al [101] used immobilized C. reinhardtii cells on polyester fabric and sodium alginate hydrogel composites for the development of a horizontal and rectangular microfluidic bioreactor, a so-called artificial leaf device, that allowed for ease of nutrient delivery from the bottom channels of the microfluidic bioreactor and H 2 collection from the headspace. They observed significantly higher H 2 -production rates for the immobilized cells grown in this bioreactor (0.58 mL H 2 h À1 g À1 dcw) in comparison with their suspended batch reactor counterparts (0.08 H 2 h À1 g À1 dcw).…”

“…They observed significantly higher H 2 -production rates for the immobilized cells grown in this bioreactor (0.58 mL H 2 h À1 g À1 dcw) in comparison with their suspended batch reactor counterparts (0.08 H 2 h À1 g À1 dcw). This approach also provided an easier cell harvesting step in the course of the experiment, and easier transitions from the S-replete to the S-depleted stage [101].…”