Production of linoleic acid‐rich lipids in molasses‐based medium by oleaginous fungus Galactomyces geotrichum TS61

Optimization of inulinase production using Jerusalem artichoke (Helianthus tuberosus) as cheap substrate and comparison with pure chicory inulin

Jerusalem artichoke (JA) is a nutritional vegetable for human diet depending on its natural structure, especially high inulin content and it is the second inulin source for commercial production in the world, after chicory. It was aimed to investigate the inulinase production capability of Galactomyces geotrichum TS61 (GenBank accession: MN749818) using JA as an economical and effective substrate comparing with the pure chicory inulin and to optimize the fermentation using Taguchi design of experiment (DOE) in this study. Besides, the effects of sucrose on inulinase production either combined with JA or in its absence were also studied. Taguchi L16 orthogonal array was employed for optimization. Both of inulinase activities obtained from JA and pure inulin gave the maximum result at the 10th experimental run as 40.21 U/mL and 57.35 U/mL, respectively. The optimum levels were detected for each factor as, 30 g/L JA, 30 g/L sucrose, pH 5.5, and four days for time. The predicted value was found as 41.63 U/mL that was similar to the obtained result as 41.17 U/mL. Finally, inulinase activity was increased approximately 8-folds after optimization. The sucrose-free medium had similar effects with higher concentrations of JA at long incubation time. This is the first investigation about inulinase production by G. geotrichum.

Production, Biosynthesis, and Commercial Applications of Fatty Acids From Oleaginous Fungi

Oleaginous fungi (including fungus-like protists) are attractive in lipid production due to their short growth cycle, large biomass and high yield of lipids. Some typical oleaginous fungi including Galactomyces geotrichum, Thraustochytrids, Mortierella isabellina, and Mucor circinelloides, have been well studied for the ability to accumulate fatty acids with commercial application. Here, we review recent progress toward fermentation, extraction, of fungal fatty acids. To reduce cost of the fatty acids, fatty acid productions from raw materials were also summarized. Then, the synthesis mechanism of fatty acids was introduced. We also review recent studies of the metabolic engineering strategies have been developed as efficient tools in oleaginous fungi to overcome the biochemical limit and to improve production efficiency of the special fatty acids. It also can be predictable that metabolic engineering can further enhance biosynthesis of fatty acids and change the storage mode of fatty acids.