Study On Catoteniod Production With Dregs Fermentation By Rhodotorula And Neurospora Sitophila

The study aims to product carotenoids, reduce the dregs crude fibre content and increase the protein content by the fermentation of Rhodotorula and Neurospora Sitophila, so as to improve the nutritional value of dregs and the effectiveness of forage. The study contains four main aspects. First, it was authenticated the isolated yeast from the preliminary experiment by cell morphology observation, physiological and biochemical characteristics analysis and molecular biology identification. The result showed that yeast lawn was orange-red, and most cells were circular or ovoid. There were various carbon sources and nitrogen sources which could be assimilated if taken budding as a reproductive pattern. The similarity of its 26S rDNA D1/D2 section sequencing results and the NCBI related sequence (registration number:in the NCBI FJ795010(Rhodotorula sp.M13) was 100%. Therefore, it could be determined as Rhodotorula. Second, the optimization of tofukasu acidolysis condition and the fermentation of Rhodotorula's tofukasu condition had achieved by single factor and orthogonal experiment. The results showed that:The optimal acidolysis conditions were that hydrochloric acid concentration was 1mol/L, in which the temperature was around 100?, acidolysis lasted 3.5 hours and the ratio of material to liquid was 1:10. Reducing sugar content was 29.1% in tofukasu acidolysis solution. The optimal fermentation conditions were that inoculating age was 48 hours, inoculation amount was 10%, fermentation temperature was 30?, pH was 6.0, speed was 250rpm, fermentation time lasted 120 hours, and the liquid volume was 80ml/250ml within a triangle flask. In this case, the red yeast biomass had reached 12.31g/L, carotenoid production had reached 2.67mg/L, and the carotenoid content had reached 216.90?g/g of biomass. Third, the optimization of the fermentation condition was by utilizing the red yeast fermentation dregs. The results were as follows. The optimal proportion of the mixed fermentation among apple, pear and tofu dregs was 3:1:1. The optimal fermentation conditions were that inoculating age was 48 hours, dry basis quantity was 7ml/10g, fermentation temperature was 28?, natural pH (measured pH6.0), the proportion of water content was 70%, fermentation time lasted 120 hours, bottling volume was 8g/250ml in terms of a triangle flask. Under this condition, the biomass quantity of the Rhodotoula fermentation was up to 82.24mg/g, carotenoid production was up to 7.56ug/g, and the carotenoid content was up to 91.93ug/g of biomass. Lastly, applying Rhodotoula and Neurospora sitophila fermentation dregs. The experiment result showed that Neurospora sitophila fermentation, Neurospora sitophila and Rhodotoula cooperative fermentation could all be produce high carotenoids. In addtion, Neurospora sitophila and Rhodotoula fermentation vinegar residue could make 49.22mg/g of biomass, the carotenoid production was up to 28.03?g/g and the its content was up to 569.48?g/g of biomass. By comparing Neurospora sitophila fermentation vinegar residue and fermentation control group, it was found that the CF total quantity reduced by 15.2%, ADF total quantity reduced by 15.7%, NDF total quantity reduced by 14.9%, which showed a significant difference (P<0.01). Total quantity of true protein increased by 5.1%, which implied a significant difference (P<0.05). The comparison of the mix fermention vinegar residue and the control group indicated that CF total quantity reduced by 22.2%, ADF total quantity reduced by 23.9%, NDF total quantity reduced by 22.8%, which also indicated a significant difference (P<0.01), crude protein total quantity increased by 3.4%, a significant difference (P<0.05), true protein total quantity increased by 9.9%, a significant difference (P<0.01).The above results showed that the fermentation by Rhodotorula could contributes to highly-yield carotenoid. The cooperation of Rhodotorula and Neurospora Sitophila fermentation could not only increaseed the true protein content of the dregs significantly, more importantly, it could lead to a high yield of carotenoid. This study had laid a solid foundation for high added value and carotenoid functional biological forage of the development of cheap and shoddy dregs.