Metabolic and genetic engineering of cyanobacteria for enhanced hydrogen production

Microalgal Systems Biology Through Genome-Scale Metabolic Reconstructions for Industrial Applications

“…It is known to interact with NADH:plastoquinone oxidoreductase and transport electrons from photosystem I during photosynthesis (Schmitz et al, 2002). Studies of hydrogen production systems have been accelerated using this hydrogenase (Khetkorn et al, 2013;McNeely et al, 2014;Navarro et al, 2009;Ortega-Ramos et al, 2014;Pinto et al, 2012;Schmitz et al, 2002). Moreover, the green microalgae Chlamydomonas reinhardtii has also garnered attention as the best eukaryotic hydrogen producer due to its transformation ability (Chochois et al, 2009).…”

Microalgal Hydrogen Production

“…Hydrogenases directly generate hydrogen to reduce protons by the accepted electrons, while nitrogenases produce hydrogen as a by‐product in the process of fixing nitrogen in the atmosphere. Another enzyme in cyanobacteria related to hydrogen metabolism is Hup uptake hydrogenase, which uptakes hydrogen instead of generating hydrogen …”

“…Nitrogenase is a multiprotein complex consisting of two parts: one is dinitrogenase (MoFe protein or protein I) and the other is dinitrogenase reductase (Fe protein or protein II). The dinitrogenase is an α2β2 heterotetramer . The α subunit and the β subunit are encoded by the genes of NifD and NifK , respectively, and the derived proteins with molecular weights of about 220–240 kDa.…”

“…V‐nitrogenase and Fe‐nitrogenase are enzyme homologs, which have significant identities with their molybdenum counterparts in terms of protein sequence and cluster composition, and lack of additional subunits (VnfG or AnfG) in the components. These three nitrogenases have different hydrogen evolution efficiency (Equations –) …”

8 Engineering of cyanobacteria for increased hydrogen production

“…This is followed by chemical synthesis of the purpose-designed DNA (2), which are assembled in selected genetic vehicles (3). In addition to the existing solar cells generating electricity, there are several options to generate solar fuels.…”