Why Clostridium ethanol protein has become a "fragrant feast"

The innovation of "breaking through a layer of window paper" in scientific discoveries can sometimes exert great potential, as evidenced by the case of "'Clostridium ethanol protein' becoming a new product of feed raw materials".

On October 30th, the Feed Research Institute of the Chinese Academy of Agricultural Sciences (hereinafter referred to as the Feed Institute) and Beijing Shougang Langze New Energy Technology Co., Ltd. (hereinafter referred to as Shougang Langze) jointly held a press conference to announce the recent breakthrough progress of their cooperative research and development team. For the first time in the world, they have realized a step of industrial biosynthesis from carbon monoxide (CO) to protein, and have formed an industrial production capacity of 10,000 tons. Based on the results of the cooperation, Shougang Langze obtained China's first new feed raw product certificate with Clostridium ethanol protein.

Breaking the "window paper", "waste" is a treasure

"The breakthrough of the innovative 'window paper' stems from the accidental combination of feed institute and Shougang Langze." Xue Min, chief scientist of the feed processing innovation team of the Feed Institute, briefly told the story behind China Science News.

A few years ago, Shougang Langze focused on the research and development of gas bio-fermentation synthesis ethanol process. The researchers found that there was also a "troublesome viscous substance" in the ethanol separation distillation process at the pilot production line, so they separated it out to figure out its composition. After being instructed, Shougang Langze later sent the sample to the feed station.

I don't know. As found in the feed, these viscous substances that are dangerously discarded are mainly proteins (Clostridium ethanol protein).

Clostridium ethanol was first isolated from rabbit guts by Belgian scientists in 1994 and is an anaerobic bacterium that produces ethanol from carbon monoxide. Xue Min told reporters that this bacterium is very special, almost people who pay attention to energy are only concerned about its ability to produce ethanol, and the bacterium itself is discarded as waste; people who focus on protein research face single-cell proteins, and the focus is mainly on traditional edible strains such as yeast, lactic acid bacteria, and microalgae. Therefore, the Clostridium ethanol protein has been "unknown" in the field of proteins for a long time.

Faced with this protein with extraordinary viscosity, the research team of the Feed Institute began to wonder whether it could function in low-starch puffed feed. So they took a step further: the functional characteristics, nutritional value, processing suitability of Clostridium ethanol protein did a systematic study, and found that its crude protein content was as high as 80%, and 18 amino acids accounted for 94% of protein, which was a simple protein type; the content of 10 essential amino acids and their structural ratios were close to fish meal, far better than soybean meal.

In short, the product has excellent feed protein raw material properties. The research team of the Feed Institute conducted experiments with a variety of farmed fish and found that the product was very suitable for use as fish feed.

Knowing this situation, the Feed Institute and Shougang Langze decided to join hands to tackle the problem and retrieve the discarded "treasure".

After 6 years of research and development and demonstration, from an annual output of 300 tons to 5,000 tons to 10,000 tons, Shougang Langze has walked through the industrialization road of new feed raw materials from pilot to large-scale production, and the feed institute has also "inadvertently" promoted the wide application of ethanol Clostridium protein from unknown bacteria to the feed industry.

Industrial exhaust gas as raw material, 22 seconds "one-step biosynthesis"

One of the highlights of this achievement is that one of the raw materials for the synthesis of ethanol Clostridium protein in the project is industrial exhaust, and a large amount of CO in industrial exhaust is an excellent raw material for the production of Clostridium ethanol protein and ethanol. The industrial exhaust gas is not only extremely low cost, but also its source is also very extensive, including steel mills, ferroalloy plants, calcium carbide plants, etc., and the amount of resources is very rich.

According to reports, Beijing Shoulang Biotechnology Co., Ltd. (hereinafter referred to as Shoulang Biotechnology), a subsidiary of Shougang Langze, uses CO-rich industrial exhaust gases to develop a new feed protein product, Clostridium ethanol protein (registered trademark "Fuyule"). The protein product has obtained a new product certificate issued by the Ministry of Agriculture and Rural Affairs on August 27, which is also the first new product certificate for feed raw materials in China.

Of course, biosynthetic proteins require not only a carbon source, but also a nitrogen source. Chao Wei, senior vice president of Shougang Langze, said that Shoulang Bio uses CO in the exhaust gas of steel mills as the carbon source and ammonia as the nitrogen source, and the optimized anaerobic fermentation process realizes rapid conversion in 22 seconds, efficiently produces ethanol and Clostridium ethanol protein, and realizes the one-step conversion of inorganic matter into organic matter.

"This is the most efficient biological carbon sequestration/nitrogen sequestration production model ever discovered internationally." Xue Min said that 22 seconds refers to the time it takes to input CO syngas and biotransform to produce ethanol and bacteria protein mash. Subsequently, the pyrolyc solution is processed into a dry powder.

In addition, because Clostridium ethanol can be fully inactivated by air exposure, the body is concentrated by centrifugation and spray dried as a Clostridium ethanol protein product, and the production cost is much lower than that of single-cell protein products such as yeast and microalgae. This also means that the use of this result for the efficient synthesis of protein by microorganisms has a significant cost-effective advantage.

Killing three birds with one stone, the protein "out of nothing" is of great significance

At the press conference, Yin Yulong, an animal nutritionist and academician of the Chinese Academy of Engineering, affirmed the breakthrough of the achievement through video connection: "The significance of the achievement to achieve industrialization is great, and I hope that the team will further expand production." ”

Dai Xiaofeng, director of the Feed Institute, told China Science News that the industrial production of biosynthetic feed proteins in one step will help China get rid of the "soybean import dependence syndrome" and achieve "carbon neutrality".

It is estimated that China can produce at least about 1.2 trillion cubic meters of CO-rich industrial exhaust every year, and if these industrial exhaust gases are used for efficient and clean utilization by biological fermentation technology, it can produce 10 million tons of ethanol protein per year, replacing fishmeal and soybean protein.

Dai Xiaofeng said that in the industrial production of 10 million tons of ethanol Clostridium protein (protein content of 83%), equivalent to 28 million tons of imported soybean equivalent, that is, 1/3 of China's annual soybean imports. At the same time, industrial biosynthetic protein also opens up a new way to "produce high-quality feed protein from low-cost non-traditional animal and plant resources", and every 10 million tons of this protein produced is equivalent to reducing carbon dioxide emissions by 250 million tons.

Li Aike, chief researcher of the Scientific Research Institute of the State Grain and Material Reserve Administration, believes that the biggest highlight of the achievement is "to solve the problem of protein shortage with microbial protein production".

He said that China has listed "microbial protein production" as a research topic since the 1980s, and the international community has long been studying the problem of synthesizing proteins from carbon compounds, but it has not been able to achieve industrialization, and the joint research and development team has made this idea a reality. He said that if a larger-scale industrialization of biosynthetic protein can be realized, it will be of great significance to China's feed protein supply and food security.

Lin Min, a researcher at the Institute of Biotechnology of the Chinese Academy of Agricultural Sciences, compared the results with biological nitrogen fixation. He suggested that the international community likes to compare biological nitrogen fixation to "air bread", so perhaps biosynthetic proteins that do not depend on plants can be compared to "producing wine and meat in tin cans".

10,000 tons of industrial production capacity has been formed, and there are still scientific problems to be solved

For the approval of Clostridium ethanol protein as a new product of feed protein, Huang Qingsheng, director of the Feed Forage Division of the Animal Husbandry and Veterinary Bureau of the Ministry of Agriculture and Rural Affairs, said that the product passed the approval of the National Feed Review Committee on its safety, effectiveness and environmental impact assessment, "worth issuing China's first new feed raw material product certificate".

Chao Wei revealed at the press conference that at present, based on the achievements of this technology and after years of layout, Shoulang Bio has achieved a three-year stable production of biosynthetic Clostridium ethanol protein pilot, and completed the construction of the production line of 10,000 tons of protein production capacity this year. Moreover, in 2022, it will further expand production and "move to 30,000 tons of production capacity.".

Chao Wei told China Science News that the reason for the rapid expansion of production capacity is "idealism" on the one hand, hoping that the large number of new feed protein products can effectively reduce the foreign dependence of China's soybeans and help "carbon neutrality"; on the other hand, "real demand", since some enterprises have evaluated and tried new products and found their advantages, the "appetite" has increased greatly, and now Clostridium ethanol protein is "in short supply".

From October 21st to 27th, Shougang Langze Bio-carbon Sequestration Technology, as one of the representative technologies in the field of "carbon neutrality", was invited to participate in the exhibition "Beautiful China Exhibition Area" of the National "13th Five-Year Plan" Scientific and Technological Innovation Achievement Exhibition.

However, Dai Xiaofeng said that although the current joint research and development team has achieved important research results, it is still only "a group of lucky children who have picked up beautiful shells on the beach", and in the future, they will carry out in-depth research on the theoretical mechanism and molecular effect of carbon monoxide biosynthetic proteins.

Xue Min also told China Science News that although he and Shougang Langze have previously conducted research on "substitution of Clostridium ethanol protein for soybean meal" and "nutritional analysis of Clostridium ethanol protein on aquatic animals" in the research framework of the "Blue Granary" project of the National Key Research and Development Program of the Ministry of Science and Technology, and have published papers in the domestic journal "Journal of Animal Nutrition" and the international journal "Aquaculture Research" and "Animal Feed Science and Technology", there is still a lot of scientific work to be carried out. She said that in the future, in the process of taking into account the research of scientific problems, we will also pay attention to breakthroughs in engineering problems and further promote the transformation of scientific and technological achievements into the main battlefield of the economy. (Reporter Zhao Guangli)

Source: China Science Daily