Fundamentals of Biochemistry - Filippovich, Y. B. 1999

Protein Metabolism
Biosynthesis of Proteins and Essential Amino Acids for Practical Purposes

It is no exaggeration to state that humanity has now entered the era of industrial protein production—the scarcest food product on Earth. On July 11, 1987, the five-billionth citizen of Earth, Matej Gaspar, was born in Zagreb. According to UN estimates, the global population will reach 6.1 billion by 2000. However, even today, 10–15% of the world's population suffers from hunger, while 40% receives an inadequate diet lacking sufficient protein content.

The industrial production of Proteins is currently carried out through three main Methods: The production of fodder Yeast, the preparation of protein-vitamin concentrates, and the extraction of proteins from non-food plant raw Materials.

The production of fodder yeast, which contains over 50% protein and is rich in Vitamins and Trace Elements, is organized using by-products from the woodworking, pulp and paper, sugar, and alcohol industries (such as sawdust and vinasse), as well as agricultural residues (straw, corn cobs, etc.).

Protein-vitamin concentrates are produced from petroleum feedstock. This type of production was first deployed on a small scale in France, with its output utilized not only in animal husbandry but also in the food industry. In our country, plants for the production of protein-vitamin concentrates were commissioned in Svetloyarsk, Kstovo, Tomsk, Novopolotsk, Kirishi, and Kremenchuk. However, their operation has given rise to environmental concerns, the resolution of which encounters both technical difficulties and public emotional resistance.

The extraction of proteins from non-food plant materials—such as tree leaves, inedible beans and seeds, and the like—has been established on an industrial scale abroad. Such protein is used to manufacture artificial meat, synthetic sausages, and other food surrogates that are gaining widespread acceptance as inexpensive substitutes for natural products. Domestically, a method has been developed for extracting food-grade protein from cottonseed. An exceptional source of feed protein is the unicellular alga Chlorella, the production of which is expanding worldwide, including in our country, Bulgaria, Japan, Germany, and others.

The application of feed protein and protein-vitamin concentrates in animal husbandry is exceptionally effective: it improves the utilization of proteins in the basic diet, increases weight gain and growth rates in young livestock, reduces feed consumption per unit of output, and dramatically raises production efficiency. Consequently, a young industry—the industrial production of proteins—faces vast Prospects. Large-scale facilities for the microbiological synthesis of protein based on ethanol and natural gas are being established, with capacities reaching 300–500 thousand tons of product per year. Regulations are also being developed for the industrial cultivation of hydrogen Bacteria, whose biomass is exceptionally rich in protein, reaching concentrations of up to 70%.

The Challenge of supplying humanity with protein is also being addressed on a more global scale. Domestically, this aspect was first examined at the 9th Mendeleev Congress on General and Applied Chemistry (Kyiv, 1965). Academician A. N. Nesmeyanov noted in his congress address that The process of food production through the cultivation of plants and animals has fundamentally changed very little since primitive pastoral and agricultural societies. Yet a century ago, D. I. Mendeleev wrote: "As a chemist, I am convinced of the possibility of obtaining nutrients from a combination of the elements of air, Water, and earth, independent of conventional agriculture—that is, in specialized factories and plants, though The Need for this is still very distant from the modern era..."

According to A. N. Nesmeyanov, the tremendous advances in synthetic chemistry, which is theoretically capable of synthesizing any organic substance, have created a realistic foundation for addressing the issue of industrial food production right now. Of the six essential nutritional components required by humans (water, proteins, CARBOHYDRATES, fats, mineral salts, and vitamins), the first and the last two already exist in nature or can easily be produced in the necessary quantities. Of the remaining three, carbohydrates and fats—which primarily serve as Energy Sources—are interchangeable and readily transform into one another. Their synthetic production or manufacture in unlimited quantities from natural non-food raw materials currently presents no difficulty.

Thus, the problem boils down to the industrial synthesis of eight Essential Amino Acids, which can fully replace dietary protein. There are already a sufficient number of chemical and microbiological methods that can serve as a basis for the commercial production of these amino acids in adequate quantities and at prices lower than protein-containing products.

Academician N. N. Semenov addressed the same problem, albeit from a different perspective, in his address at the anniversary session dedicated to the 250th anniversary of the USSR Academy of Sciences (December 1978). He raised the question of the necessity of modeling the Photosynthesis process—which currently operates at an efficiency of only 1.5%—and raising that efficiency to 30%. This would lay the groundwork for generating energy on artificial energy fields and producing food (mediated by that energy) in factories.

Another crucial aspect of obtaining proteins for practical purposes was outlined by Academician A. S. Spirin in his address at the anniversary session of the USSR Academy of Sciences (March 1987). It involves transcending THE CELLULAR LEVEL of METABOLISM/35.html">Protein Biosynthesis and transitioning to scaled-up synthesis in continuous-mode Cell-free Translation systems operating under flow conditions. This will open up possibilities for producing biologically significant proteins (interferon, Insulin, a₁-antitrypsin) and medical-grade Peptides, enable the design and production of proteins with custom-tailored properties, and elevate The Study of the chemical coevolution of proteins and Nucleic Acids to a new level. A decisive role here is played by generating the required quantities of corresponding mRNAs in systems containing RNA-dependent RNA polymerase, such as phage Q_β replicase. A solid-phase translation apparatus of the continuous Reactor type has already been created and tested using brome mosaic virus RNA-4, phage MS2 RNA, and Calcitonin mRNA. These studies on cell-free Protein Synthesis are being conducted within the framework of the State Scientific and Technical Program "Advanced Methods of Bioengineering." Even today, under laboratory conditions in small bioreactors, this method can yield sufficient quantities of Peptide Hormones, diagnostic Antigens, protein toxins and antitoxins, antiviral protective proteins, and certain Enzymes for further research. The revolution in molecular biology and biotechnology continues.