Enzymes photosynthesizing fuels, organic chemical industrial feedstocks, and bulk macronutrients (fats, sugars and amino acids) from air, seawater and sunlight will be readily developed by mechanomeric selection (MeSe).
The critical argument with regard to mechanomeric selection is presented here.
A very concise report giving the background to that argument, the argument itself, a technological description of mechanomeric selection, and a small number of brief descriptions of medical and industrial applications of that technology, including artificial photosynthesis, is presented here
And a more expansive and easier-going introduction to mechanomeric selection in the form of a pseudoblog/FAQ is presented here (start with the earliest post, in blog fashion).
Seawater should be used for artificial photosynthesis wherever possible to minimize usage of and impact on freshwater.
Such photosynthesis should not use the ordinary biological photosynthetic frequencies (blue and red) on land, to avoid competition with natural photosynthesis, and should probably best use solar UV both on land and at sea, to avoid such competition and since UV penetrates cloud well and is high-energy.
And such photosynthesis should be as decentralized as possible (eg, every building/complex, municipality, etc., should generate its own fuel as much as possible, for electrical and vehicle-fleet use), not least in implementation in the form of specialized ocean-going photosynthetic barge-fleets(which barges should be transparently-bottomed, to allow unused sunlight to pass through).
The mechanomeric selection of a photoenzyme for such photosynthesis will involve matricial mechanomeric selection (see the referenced report and pseudoblog/FAQ): matriciating (usually meaning chromatographically two-dimensionally arraying) replicated random mechanomers (functional copolymers) of some artificial class (to avoid unintended consequences), say polyesters or polysulfonamides; overlaying the replicated random mechanomer matrix so produced with seawater and if desired or needed a mixture of metal ions and organic chemicals (chromophores and electrophores) facilitating photonic absorption and electronic transmission and/or some desired substrate or reactant; exposing the functional matrix so produced to sunlight; and examining that matrix for the emergence of the desired product (best using mechanomeric indication by a previously-developed enzyme, an indicase, and its substrate or indicator together reacting to and therefore indicating the presence of that product by catalyzing an indicating reaction causing a color-change—see the referenced report and pseudoblog/FAQ); followed by extraction of the mechanomers from locations where that product is being produced; replication of those mechanomers; and their further testing for the desired catalysis, for example by further selections using different matriciations.
Desired photosyntheses might be broken down into sequences of simpler reactions and the enzymes (photosynthetic or otherwise) catalyzing those separately selected, but there should usually be at least an initial or parallel attempt at the easiest one-shot selection of a necessarily more complex enzyme (and therefore one occurring less frequently in random mechanomer stocks) capable of catalyzing all those reactions in sequence and therefore the entire sequence from air, seawater and sunlight to final product, such enzyme being simplest to use in practice.
Similarly, where such simpler enzymes are selected, it might be best to select them in order of needed catalytic sequence, and use each enzyme/complex selected as an additional component of the next selective matrix, in an attempt in each selection to select an enzyme which complexes with the previously-selected enzyme or complex and catalyzes the growing sequence of reactions most efficiently.
One of the most important artificial photosynthetic products will be glucose, for use in cellophane (biodegradable bagging/wrapping plastic), (cellulose) paper, and the textile rayon.
And another will be lignin precursors or equivalents for use in lignin and artificial wood syntheses for light and medium construction.
Note that selection and use of such enzymes for such photosynthesis of fuels, organic chemical industrial feedstocks, and bulk macronutrients will not only halt the alarming present-day massive industrial crustal-carbon fossil-fuel extraction and burning and consequent carbon dioxide emission and greenhouse warming, but will also remove carbon dioxide from the atmosphere and "fix" it into fuel and other stocks, helping palliate the impact of previous extraction and burning and emission and warming.
And once the fuel, organic chemical and food industries are retooled away from use of petroleum to that of photosynthetic products, we will have finally established the sustainable photosynthetic economy or photonomy.
Keywords: bionanotechnology, enzymes, mechanomeric selection, mechanomers, MeSe, photonomics, photonomy, photosynthesis, Singularity, sustainability