Microbial oil triacylglycerol (TAG) from the renewable feedstock attract much attention. The oleaginous yeast Yarrowia lipolytica has become the most studied for lipid biosynthesis. Fatty acid desaturases catalyze the introduction of a double bond into fatty-acid hydrocarbon chains to produce unsaturated fatty acids. Desaturases are known to enhance lipid accumulation. In this study, we have achieved a significant increase in lipid production and increase the unsaturated fatty acids content in Y. lipolytica. By comparing the expression of the native genes of-9 stearoyl-CoA desaturase (SCD) and 12 desaturase (12D), and an exogenous 15 desaturase (15D) from flax in the strain with deleted peroxisomal biogenesis factor 10 (PEX10) and overexpressed diacylglyceride acyl-transferase (DGA1), we found that the strain with overexpressed 15 desaturase accumulated 30.7% lipid. Simultaneously, we explored the effect of two copies of desaturase genes (12D-SCD, 15D-SCD, 12D-15D) on lipid production, and found co-expression of 12D and 15D accumulated 42.6% lipid. The lipid content was further increased by 56.3% through the deletion of the multifunctional enzyme (MFE1) and the overexpression of acetyl-CoA carboxylase (ACC1). Finally, the lipid productivity of 50 g/L and maximal lipid content of 77.8% DCW are obtained using a 5-L stirred-tank bioreactor during the stationary phase in the engineered YL-10. Our result demonstrated that the 12 and 15 desaturases play an important role in lipid production in Y. lipolytica and provides an effective strategy for biodiesel development.

With the development of wireless sensor network (WSN), Internet of Things (IOT) has been widely adopted by different fields. Cultural heritages preservation is one of the typical application scenes in these fields. The cultural heritages are always in the special environments, such as open land or damp tomb cave, which is very suitable for IOT. In this paper, some current preservation technologies and solutions are analyzed, and existing problems are described. Finally, a novel cultural heritage preservation solution based on IOT is proposed, and a corresponding prototype system is introduced and verified.