Making meat out of nothing, can industrial exhaust gas also be turned into "four dishes and one soup"? ! 丨 Great Power Technology Fan

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A few days ago, the promotion and introduction of artificial meat was overwhelming and hotly discussed by major media. However, almost at the same time, China also "quietly" announced a major breakthrough - using industrial exhaust gas to produce protein and completed a production capacity of 10,000 tons!

When I first heard the news, I couldn't help but imagine many apocalyptic scenes, with severe air pollution, withered things, and people scrambling for food resources. If this technology can be fully realized in the future, does it mean that industrial exhaust gas can also be recycled ?

Source: Movie "Escape from the End"

On the bright side, in the interstellar travel constructed in science fiction movies, there are similar black technology scenes. As long as you confirm the name of the food with the computer, you can directly get all kinds of food and drinks. So, in the future space travel, do we not have to worry about food reserves?

Source: American TV series "The Orville" After all, in the industrial age, there is no shortage of exhaust gas...

But wait a minute... artificial meat has been so controversial so far, not to mention the toxic-sounding industrial exhaust gas. Is it really okay to produce something like this?

This matter has to start with what kind of protein it produces.

Where does protein come from?

The protein produced is nothing new. In fact, it is a biological metabolite. However, this protein is different from the previous starch synthesized from carbon dioxide or artificial meat. It is not an artificially synthesized industrial product, but a metabolite directly produced by microbial fermentation technology, just like yogurt.

The microorganism it uses is called Clostridium ethanolum , a common strain of bacteria used in industrial ethanol production. It can react with carbon-containing industrial tail gas to produce ethanol mash, and finally obtain ethanol through distillation. Source of Clostridium ethanolum | Photo provided by the Feed Research Institute of the Chinese Academy of Agricultural Sciences But! Everyone should remember one sentence: Nothing is garbage, it’s just resources used in the wrong place!

In previous industrial production, people often found that a very sticky paste in the distillation tower blocked the tower plate, causing the operation of the distillation pipeline system to be blocked and the yield to be seriously affected. The technicians have been trying to solve this tricky thing and find a way to remove it. A Beijing ethanol production company put forward a constructive suggestion to separate it out and test whether it has any use value.

At this point, a brand new corner of the world's "New World" has been revealed.

Source: China Biotechnology Network

After the researchers conducted a large number of experiments and separated the protein, it was sent to the National Feed Quality Supervision and Inspection Center (Beijing) for testing. The results showed that the main component of the paste is called Clostridium acetate protein . Its protein structure is simple, the crude protein content is over 83%, and 18 kinds of amino acids account for 94% of the protein. The content and structural ratio of 10 essential amino acids are close to fish meal and far better than soybean meal, and the heavy metal content does not exceed the standard.

In addition, after conducting experiments on a variety of common fish, the researchers found that adding 3%-4.5% of Clostridium acetate protein to the feed can significantly improve the gastrointestinal and liver functions of fish; when the proportion is increased to about 18%, there is no adverse effect on the growth, blood biochemical indicators and liver and intestine tissue morphology of fish. In addition, its fluidity, viscosity, water solubility and other indicators are also good, and it has good feed processing conditions.

In other words, this protein is a relatively safe protein feed raw material.

The turnaround of Clostridium ethanolica

Next, when we introduce the produced protein, we need to review its "mother" - Clostridium ethanolum. Since it is a natural biological metabolite, why is its use not discovered until now?

It can only be said that it is the inertial thinking that causes the problem.

Ethanol Clostridium was originally isolated from the intestines of rabbits by Belgian scientists, and used as a fermentation strain to produce ethanol using carbon monoxide or carbon dioxide as a carbon source. This research has been carried out for many years in various countries.

Rabbit source: Wikipedia

Most energy research focuses on the use of carbon monoxide to ferment chemicals such as acetic acid and ethanol, and there is very little research on proteins synthesized by microbial strains and their functions. Even scientists who specialize in microbial protein focus their research on yeast, lactic acid bacteria, microalgae and other strains that are traditionally considered edible, which has led to microbial proteins such as ethanol Clostridium becoming "passersby" or "garbage" in the protein field for a long time.

As for the significance of this research and the use of the fish feed developed, we have to start with the "ration" of animals in my country - feed.

Whether you have raised poultry or livestock or not, you must have a certain understanding of the ingredients of animal feed. There are two indispensable things in it: corn and soybean meal , which represent energy feed and protein feed.

To support my country's huge breeding industry, my country's feed output reached 290 million tons in 2021, ranking first in the world, and the annual feed consumption is about 450 million tons. If energy feed is not taken into account, a simple estimate shows that 80 million tons of pure protein feed will be needed.

In recent years, my country has been extremely short of high-quality protein raw materials for feed and has had to import a large amount of them, with foreign dependence remaining above 70% for a long time. my country imports about 1.5 million tons of fish meal and about 100 million tons of soybeans each year, and consumes about 70 million tons of soybean meal for feed each year.

Source: Wikipedia

Due to the high price of animal protein and the fact that plant protein is affected by factors such as small cultivated land area, changeable climatic conditions, long production cycle, and low material and energy conversion efficiency, it is difficult to significantly increase production capacity. For a period of time, my country will not be able to get rid of the situation of importing feed protein raw materials.

Assuming that 10 million tons of ethanol Clostridium protein (protein content 83%) are produced industrially, it is equivalent to 28 million tons of imported soybean equivalent, which is equivalent to one-third of China's annual soybean imports . This will help China get rid of the "soybean import dependence syndrome."

In addition, China produces at least 1.2 trillion cubic meters of CO2-rich industrial exhaust gas each year. If these industrial exhaust gases are efficiently and cleanly utilized using bio-fermentation technology, 10 million tons of ethanol clostridial protein can be produced annually, which is equivalent to reducing carbon dioxide emissions by 250 million tons.

Soybean source | Wikipedia

However, it should also be noted that new feed protein sources such as ethanol Clostridium protein still need to be further studied to further improve their quality and utilization efficiency. It is now urgent to further reduce costs and increase protein production by improving strains and production processes.

Although the total amount of ethanol Clostridium protein is not yet at the level of replacing soybeans, it would be great if it could solve the dependence on protein feed imports in the future. At least there is technology to use industrial exhaust such as carbon monoxide to produce bacterial protein, which will have endless possibilities.

Under the call of the "dual carbon" goal, this technology that both reduces carbon emissions and protects the environment will surely help achieve "carbon neutrality" as soon as possible.

In addition, it should be noted here that automobile exhaust contains not only carbon-containing gases, but also harmful gases such as nitrogen oxides, sulfur oxides, lead compounds, etc. How to remove them and whether they will affect the conversion of carbon-containing gases into proteins by Clostridium ethanolum are all issues that we must consider in reality.