Insights on biological hydrogen production routes and potential microorganisms for high hydrogen yield

Hydrogen Environmental Benefits Depend on the Way of Production: An Overview of the Main Processes Production and Challenges by 2050

“…Besides being eco-friendly and carbon-free, biohydrogen has the advantage of being able to use a wide range of substrates to produce hydrogen, from biomass, to different types of organic wastes, which increases the range of applications for biohydrogen production. [128][129][130] The fundamental basis of microbial H 2 production is that the microorganisms act as the catalysts for the reaction, forasmuch as they can use redox reactions to obtain hydrogen. In general, they use protons (H þ ) and electrons (e À ) that are generated in some internal enzyme's reaction, to combine and form H 2 , as it is shown in the following equation.…”

“…In general, they use protons (H þ ) and electrons (e À ) that are generated in some internal enzyme's reaction, to combine and form H 2 , as it is shown in the following equation. [128,131] 4 H þ þ 4 e À ! 2 H 2 (12) The different processes of biohydrogen production will change in terms of electron donor types, redox potentials, the substrate type, and the microorganism that will be responsible for carrying out the overall processes.…”

“…These processes will be briefly discussed subsequently, and Table 1 summarizes the main advantage and disadvantage for each process. [128,[131][132][133] Direct Biophotolysis: Direct biophotolysis for biohydrogen production is based on the photosynthesis system, a complex redox process that can be accomplished during the metabolic cycle in green algae and plants cells. [128,134] In this process, a microbial photosynthesis mechanism uses solar energy to convert a water molecule into molecular hydrogen and oxygen, being a combination of biological and chemical processes.…”

“…[128,[131][132][133] Direct Biophotolysis: Direct biophotolysis for biohydrogen production is based on the photosynthesis system, a complex redox process that can be accomplished during the metabolic cycle in green algae and plants cells. [128,134] In this process, a microbial photosynthesis mechanism uses solar energy to convert a water molecule into molecular hydrogen and oxygen, being a combination of biological and chemical processes. During the mechanism, photosystem I (PSI) and photosystem II (PSII) play an important part in the H 2 production process.…”

Effect of Superficial Gas Velocity on Continuous Hydrogen Production by Anabaena sp. in an Internal-loop Airlift Bioreactor

“…A signi cant number of bacteria, cyanobacteria and green algae such as Chlamydomonas, Scenedesmus, Chlorella, Tetraspora are able to produce biological hydrogen [10,11]. Anaerobic cultures of microorganisms such as Clostridium, whose carbon source is supplied by carbohydrates such as glucose, are able to produce hydrogen gas during the fermentation process [12,13]. Photosynthetic bacteria such as Rhodobacter have the ability to use carbon sources such as lactic acid and acetic acid as energy sources and produce hydrogen gas under light conditions [14].…”