Production of Polyunsaturated Fatty Acids by Fungal Biofactories and Their Application in Food Industries

Lipids form an important constituent of our diet. Polyunsaturated fatty acids (PUFAs) are a class of lipids that are generally considered as safe and often recommended by dieticians and nutritionists. They are known to regulate a number of biological activities in humans. Therefore, PUFA supplementation in processed food has been commercially exploited especially in infant nutrition where lipid concentrations of formula milk are made to mimic breast milk by addition of commercially prepared PUFA. Plants and animals had been the conventional sources of PUFAs in food. However, with rising population, this demand is difficult to be met only by these sources. The discovery of lipid-producing fungi and yeast especially oleaginous fungi which can accumulate 20% or more of their cell dry weight as lipids has opened a new domain for PUFA production. Therefore, production of PUFAs from fungi is currently viewed as an attractive field of biotechnological importance. However, industrial application of fungi is still limited by high fermentation cost. Currently, utilization of agro-industrial wastes to reduce substrate cost is a highly explored area in microbial lipid research. Further, research is also directed towards development of robust fungal strains that are non-toxic and can accumulate high amount of food grade lipids and easy to cultivate with more efficient downstream extraction processes. An understanding of the underlying principles of lipid synthesis in fungi is therefore required to achieve the desired results. In future, emerging technologies in the field of synthetic and system biology can provide more meaningful insight into fungal lipid metabolism which can make it much easier to manipulate them.