Biohydrogen production beyond the Thauer limit by precision design of artificial microbial consortia

Abstract

Dark fermentative biohydrogen (H 2) production could become a key technology for providing renewable energy. Until now, the H 2 yield is restricted to 4 moles of H 2 per mole of glucose, referred to as the "Thauer limit". Here we show, that precision design of artificial microbial consortia increased the H 2 yield to 5.6 mol mol −1 glucose, 40% higher than the Thauer limit. In addition, the volumetric H 2 production rates of our defined artificial consortia are superior compared to any mono-, co-or multi-culture system reported to date. We hope this study to be a major leap forward in the engineering of artificial microbial consortia through precision design and provide a breakthrough in energy science, biotechnology and ecology. Constructing artificial consortia with this drawing-board approach could in future increase volumetric production rates and yields of other bioprocesses. Our artificial consortia engineering blueprint might pave the way for the development of a H 2 production bioindustry.

Control of synthetic microbial consortia in time, space, and composition

“…Modern engineered biological systems are able to solve more complex problems than ever before. Bioproduction is increasingly able to synthesize valuable plant-based products, significantly reducing production time [1][2][3]. Novel gene circuit topologies continue to increase in complexity as our understanding of the genetic code and its regulation deepens [4,5].…”

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.…”

“…Although it has a relatively high yield, the yield of H 2 per substrate consumed (Y (H2/S) ) is limited by metabolic constraints of dark fermentative microorganisms, following the theoretical limit, known as "Thauer limit." [128,129] Thus, these systems still present some drawbacks that need to be overcome to make it more suitable. [144] Photo-Fermentation: Photo-fermentation is a process in which a photosynthetic microorganism uses light (sun or artificial) and consumes reducing sugars and organic acids, producing hydrogen.…”

A Review of Enhancement of Biohydrogen Productions by Chemical Addition Using a Supervised Machine Learning Method

“…For microbes to initiate their metabolism, elements such as Mg 2+ , Na + , NH 4 + , and K + are essential [82][83][84]. These elements usually act as the major components of active centers in many enzymes [85][86][87]. Ensuring a sufficient amount of these necessary elements will facilitate the smooth and fast transition from the lagging phase to the growth phase [88][89][90].…”