BIOTECHNOLOGY - V. H. Herasymenko - 2006

Part II. Special Biotechnologies

Chapter 21. BIOTECHNOLOGY OF PROTEIN PRODUCTION

21.4. PRODUCTION OF MICROBIAL PROTEIN FROM PETROLEUM REFINING BY-PRODUCTS

Until recently, petroleum Hydrocarbons (purified n-paraffins and petroleum distillates) served as a promising raw material source for feed protein production. They are assimilated by a specific group of microorganisms comprising at least a thousand species. Scientists have established that The ability to utilize petroleum and petroleum products is shared by numerous Bacteria and microscopic Fungi naturally occurring in the soils of oil fields and extraction sites.

In the 1960s, Western oil companies developed a technology for cultivating the Yeast biomass Candida lipolytica on purified n-paraffins (n-alkanes) extracted from petroleum. By 1973, the Soviet Union had launched the world's first industrial plant for producing feed yeast from petroleum n-alkanes, with an annual capacity of 70,000 tons. As of 1988, there were 86 operating facilities across the country producing microbial protein.

While either yeast or bacterial cultures can be employed as producers, Yeasts belonging to the genus Candida—such as C. guilliermondii, C. maltosa, and C. sake—have become the most widely adopted. Under optimal cultivation conditions, these microorganisms are capable of achieving a high substrate (n-alkane) assimilation rate of up to 40% and accumulating substantial amounts of protein (exceeding 60%).

The resulting protein product derived from liquid paraffins or n-alkanes (known as paprin) contains approximately 60% crude protein, up to 5% fats, 10–20% easily digestible CARBOHYDRATES, 5–8% mineral matter, as well as B-group Vitamins and ergosterol.

However, due to limited raw material resources and rising costs, this technology is no longer utilized for large-scale industrial protein production.

Alternative substrates for microbial protein production include methane-containing gases, lower alcohols (methanol, ethanol), plant-derived carbohydrates, and, looking forward, hydrogen.