Read this article to learn about the production of single-cell oils.
Microbial Lipids:
Among the microorganisms, the eukaryotes can accumulate triacylglycerol’s. In contrast, prokaryotes predominantly accumulate polyhydroxyalkanoates.
Microorganisms as oil factories:
In general, commercial oils (and fats) used in foodstuffs and cosmetics are obtained from plants and animals. Thus, the traditional sources of oils are plants and animals. In recent years, microbial production of oils is gaining importance.
There is a trend to use microorganisms as oil factories for the following reasons:
1. Plant oils contain residues of pesticides and herbicides that are used in the cultivation of oil seed plants.
2. Fats and fatty acids from animal sources are unacceptable by some sections of the society on moral and/or religious grounds. Further, animal fats have the risk of transfer of disease-causing agents (e.g. prions) to humans.
3. The eukaryotic microorganisms are capable of producing a wide range of polyunsaturated fatty acids. Certain microorganisms can synthesize huge quantities of a single fatty acid which is quite advantageous for large scale production and easy recovery of a particular fatty acid.
4. Microbially produced oils which are devoid of harmful contaminants will be acceptable to the public on moral and ethical grounds also.
Production of Single-Cell Oils:
Oils rich in a particular fatty acid are regarded as single-cell oils. So far, researchers have been successful in producing single-cell oils rich in three polyunsaturated fatty acids. These developments have occurred due to the interest taken by multinational pharmaceutical companies.
Linolenic acid:
Single-cell oil rich in linolenic acid was the first oil produced by the fungus Mucor circinelloides. Its production however, was later discontinued due to cost factor.
Arachidonic acid:
The soil fungus, Mortierella alpina has been used for the production of oils rich in arachidonic acid.
Docosahexaenoic acid:
The marine alga, Crypthecodinium cohnii has been employed for commercial production of decosahexaenoic acid (DHA). Microbial DHA is used for inclusion, in baby foods.
Limitations in the production of single-cell oils:
The fermentation technology used for the production of single-cell oils is very expensive. It is visualised that the day may not be far off to transfer the genes producing single cell oils from microorganisms to plants. These transgenic plants can produce large quantities of single-cell oils more cheaply. But these oils will be genetically engineered, and therefore, it is doubtful whether they will have wide-spread public acceptance.