Research On The Impact Of Metal Ions And Rhodotorula Glutinis On Growth And Oil Accumulation Of Spirulina

Microbial grease is an important raw material of biodiesel fuel. Spirulina can use the wastewater and waste gas from factories. And Spirulina can also use the alkali lake which other plants can't grow. This makes the cost lower. Besides, Spirulina has advantages such as fast growth, large biomass, low carbon emissions and so on. Rhodotorula glutinis is one of higher oil producing yeast which grows fast. Its growth cycle is short and can use waste of factories such as molasses. Therefore, this article studied on the impact of metal ions and Rhodotorula glutinis on growth and oil accumulation of Spirulina, and the purpose is to improve the oil content of Spirulina. This research did a exploratory research of feasibility of Spirulina as a raw material of biodiesel fuel. The main conclusions are as follows:1. This article studied on and compared several grease content determination method of Spirulina oil content. Acid hydrolysis method is suitable for the determination of Spirulina oil content. Because sampling of this method is liquid, sampling quantity is little and it can fast determination. The study found that Nile red fluorescent cannot measure oil content of Spirulina. When the fluorescent is scanning, characteristic peak did not show at 580nm, but the characteristic peak of Spirulina algae blue protein showed at 640nm. Using Nile red fluorescent as determined of Spirulina algae blue protein content had feasibility to do further research, and has the vital significance for the quicker and easier algae blue protein determination method.2. The temperature had a significant effect not only for the Spirulina growth, but also for its oil content. Under the temperature of 30℃, Spirulina growth and the oil content were the biggest. This showed that changing conditions can get high biomass and high oil content of Spirulina.3. Based on the Spirulina medium, this article researched on 7 kinds of metal ions, and the results showed that increased calcium, the liquor sodium, ferrous ions and zinc ion in different degrees can increase the biomass of Spirulina. The important effect ions (ferrousion ions, zinc ions) and medium pH value is the three factors of orthogonal experiment. The experimental results showed that the main factor which affected the biomass of Spirulina most is ferrous ion concentration of Spirulina medium. The best cultivation condition is that medium pH of 9.0, ferrous ion concentration of 10.8×10-5 mol/L, zinc ion concentration of 7.6×10-7 mol/L. So the article chose medium pH of 9.0, ferrous ion concentration of 10.8×10-5 mol/L, zinc ion concentration of 7.6×10-7 mol/L to obtain larger biomass of Spirulina.4. This article studied on the basis of malt juice medium, and researched on the temperature, medium pH, medium type and medium metal ion content. The results showed that the temperature, medium pH, medium type had large effects on the growth and the oil content of Rhodotorula glutinis. When the temperature for 30℃, medium pH for 5.0, culture medium for medium B made the growth and the oil content of Rhodotorula glutinis were the biggest. This showed that changing conditions can get high biomass and high oil content of Rhodotorula glutinis. Adding 5 kinds of metal ions to the medium B, the results showed that there had no effect on the growth and oil accumulation of Rhodotorula glutinis. That is to say the metal ions of Spirulina medium had no obvious influence of the growth and the oil accumulation of Rhodotorula glutinis. The best cultivation condition is temperature for 30℃, medium pH for 5.0, culture medium for medium B.5. Based on the research of the impact of the culture condition and metal ions to Spirulina and Rhodotorula glutini, mixed these two microbial (in accordance with the different volume ratio) and mixture cultivated 48 hours. The mixed cultivating result showed that mixed cultivating Spirulina and Rhodotorula glutinis can promote the growth and oil accumulation of the mixture. The biomass and oil content of mixture is the highest when the Spirulina and Rhodotorula glutinis mixture ratio is 1:1. The biomass increased from 4.44 g/L to 5.97 g/L, and the grease content increased from 27.36% to 31.12%. Before mixed cultivating Spirulina and Rhodotorula glutinis, the biomass of Spirulina accounted for about 25% of mixture biomass. This is equivalent to increase Spirulina oil content from 6% to 31.12%, and also explains the Spirulina and Rhodotorula glutinis mixed cultivating increase its oil content approach is feasible. This is one reason for increasing oil interaction of the mixture of Spirulina and Rhodotorula glutinis, and it deserves to further study.This article researched on the impact of metal ions and Rhodotorula glutinis on growth and oil accumulation of Spirulina, and optimized the cultivation condition of the Spirulina and Rhodotorula glutinis cultivating conditions, and also mixed the two kinds of microbe cultivated 48 hours to make the biomass and oil content of mixture increased greatly. Then the purpose of promoting the oil accumulation of Spirulina was reached, and this article provided application foundation of oil of Spirulina as the biodiesel raw material. This has important significance to the western development, the use of disused lake, energy conservation and emission reduction, and also the sustainable development of economic and ecological environment.