Study On The Fermentation And Omics Of Rhodosporidium Toruloides

Rhodosporidium toruloides is a bioengineering strain with great development and utilization potential,which can be used to produce bio-oils and carotenoids.The bio-oil produced is mainly 16-and 18-carbon fatty acids that can be used as biodiesel.The carotenoids produced are mainly torularhodin,torulene,β-carotene and a small amount ofγ-carotene.These carotenoids contain a large number of conjugated double bonds,so they have good antioxidant properties and are widely used in anti-tumor,medical care,food addition,cosmetics addition and other fields.The main research contents and results of this article are as follows:First,the morphological observation of three strains of Rhodosporidium toruloides WT,M14 and M18,the color of the three strains in the nitrogen-limited medium gradually deepened,WT turned orange-yellow,M14 turned orange-red,M18 became brick-red,spots appear in individual cells.The pigments and oils were extracted by mechanical grinding method,and the three pigments in Rhodosporidium toruloides were qualitatively determined by HPLC standard products as torularhodin,torulene andβ-carotene.The qualitative analysis of fatty acids by GC-MS was 13 Species include C14:0,C15: 0,C16: 0,C16: 1,C17: 0,C18: 0,C18: 1,C18: 2,C18: 3,C20: 0,C20: 1,C22: 0,C24: 0,using GC to quantitatively find that the main fatty acids are C16: 0,C18: 0,C18:1,C18: 2,M18 has the best fat production capacity,and M14 contains more C18: 2.The second-and third-generation simultaneous sequencing of the excellent performance pigment-producing and oil-producing strain M18 resulted in a genome size of 21.31 M and a GC content of 61.79%.Functional annotations were made to the genome.A total of 7539 codeable genes,173 non-coding RNAs,and 219 transcription factors were obtained.Transcriptome sequencing of 12samples obtained a total of 35.4G data,with an average Q30 of 94.55%.The number of expressed genes in all 12 samples was 79,027,and the number of genes expressed in each sample was more than 6000.Nuclear density curve analysis,box plot analysis,and cluster analysis between samples show that the samples have good repeatability.Differentially expressed genes were analyzed for 1d-WT and 1d-M18,and a total of 6621 effective differentially expressed genes were obtained,of which 3240 were up-regulated genes and 3381 were down-regulated genes.GO analysis,KEGG analysis,and WGCNA analysis were carried out on the differentially expressed genes,and finally the gene modules related to the metabolism of torularhodin,torulene,β-carotene,and oil metabolism were determined.Using molasses instead of glucose for deep fermentation of strain M18,glucose fermentation is superior to molasses fermentation in the production of 3 kinds of carotene and 12 kinds of fatty acids,but from the perspective of economic cost,it is cheaper to use molasses fermentation to produce β-carotene,total oil and C17:0.The maximum yields of torularhodin,torulene and β-carotene in nitrogen-limited medium are(9.03±0.15)mg /L,(14.74±0.43)mg/L and(573.14±17.09)mg/L phase,respectively.Compared with the molasses medium,it was increased by 4.56 times,2.74 times,and 1.29 times,respectively.The highest yield of C14:0,C15:0,C16:0,C16:1,C17:0,C18:0,C18:1,C18:2,C20:0,C18:3,C20:1,C22:0 in nitrogen limited medium were(25.35±1.78)mg/L,(4.71±0.42)mg/L,and(537.27±27.47))mg/L,(18.99±1.01)mg/L,(12.02±0.41)mg/L,(198.40±12.76)mg/L,(1173.31±55.68)mg/L,(135.75±2.70)mg/L,(54.94±3.76)mg/L,(20.71±0.77)mg/L,(4.53±0.16)mg/L,(9.33±0.57)mg/L were increased by 4.41 times,* times,3.88 times,* times,1.16 times,2.16 times,3.53 times,7.61 times,3.03 times *Times,2.34 times,2.39 times,respectively,compared with molasses medium(*Times indicated that the fatty acids were not detected in the molasses medium).