Monday, January 21, 2019

Methanogenesis, Synthetic Biology and the Biogas Industry

Methanogenesis or biomethanation in a biogas plant is an important process resulting in the formation of methane. The methane can be collected and used as biogas, a renewable fuel.

Most of this biogas is produced from biomass on farms, but biogas can also be produced during anaerobic wastewater treatment. Wastewater treatment methods include methanogenic anaerobic digestion, and when used this technology results in the production of biogas and clarified effluent.

But, to be effective in producing biogas in quantity, anaerobic digestion needs to be conducted within the ranges which existed for millennia in nature, and these are called the mesophilic and thermophilic temperature ranges.

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Methanogenic compositions in biogas reactors and methanogenic communities in reactors are only established in fully anaerobic conditions, and currently only when operated at those optimum temperatures.

But, does it always have to be like this? Could we alter when biogas is made, including make biogas efficiently a low temperatures.

There would be massive benefits from this, especially for cold climate regions.

To go any further, let us explain a little about the all-important bugs (methanogens) needed to make biogas:

Methanogens are microorganisms that produce methane as a metabolic byproduct in hypoxic conditions. They are prokaryotic and belong to the domain of archaea. They are common in wetlands, where they are responsible for marsh gas, and in the digestive tracts of animals such as ruminants and humans, where they are responsible for the methane content of belching in ruminants and flatulence in humans.

The methanogenic archaea populations play an indispensable role in anaerobic wastewater treatments. via Wikipedia

Image shows featured image for synthetic biology to alter thermophilic and mesophilic methanogenesis conditions.
To create genetically engineered existing DNA sequences, through synthetic biology would allow scientists to build entirely new sequences of DNA and put them to work in cells.

This would allow the building of novel biological devices that would never exist in nature. This is known as synthetic biology.

Synthetic Biology and the Biogas Industry

Essentially a process operating by living organisms, the biogas industry is a natural target for synthetic biology. In terms of their genetic content, organisms are classified into three natural groups, Archaea, Bacteria and Eukarya. Most microbes are Archaea and Bacteria, while humans are Eukarya.

In an anaerobic digester, many different types of Bacteria convert the complex organic matter in waste or biomass to hydrogen gas, carbon dioxide, formate and acetate. A unique group of methanogenic Archaea then produce the invaluable part of biogas, methane, by eating hydrogen and carbon dioxide, formate or acetate.

One can imagine creating a super microbe to convert the complex organic matter directly into biogas, thus making anaerobic digestion faster, more efficient and easier-to-manipulate. Making a synthetic microbial community by reprogramming key microbes may also help them work together when a tough job (i.e., eating extremely complex waste) needs to be done.

Among numerous microbes in anaerobic digester, methanogenic Archaea are one of a few microbial groups that have been extensively studied, and a number of genetic tools are available for engineering via synthetic biology.

Therefore, scientists have begun to reprogram methanogenic archaea, allowing them to eat organic matter such as sugars and directly produce methane. If they succeed, they may engineer a super microbe that never existed in nature and revolutionize the biogas industry by making anaerobic digestion much simpler and more efficient.

Concluding - The Huge Potential for Synthetic Biology in the Biogas Industry


Synthetic biology, applied to methanogenesis, holds great potentials to revolutionize the biogas industry.

To achieve this goal, joint efforts between the biogas industry and academia must be made.

The former side needs to understand what synthetic biology can achieve, while the latter side should identify which parts of the process in the biogas industry can be re-designed and optimized by synthetic biology. via BioEnergy Consult

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