Isolation Of Energy Microalgae And Research On Its Bio-fuel Production

With deeper development of industrialization and dramatic increase of global population, the world is faced with energy crisis. The energy supply has become a significant restraint factor for the development of economy and eco-environment. A new energy pattern of sustainable, renewable, high-efficiency and low-cost is required to substitute the traditional fossil fuels. Biofuel, produced by biomass, is a promising substitute to fulfill the future energy demand. Marine microalgae are a primary provider of organic matter and energy in the marine ecosystem. Compared with other energy sources, it has advantages of being of high fat content, short growth period and high production. It has drawn more and more attention worldwide.The research aims to establish an effective protocol to find out the microalgae species of high biomass, high cellulose content or high grease from the collections of microalgae in natural waters to benefit the energy research, and to lay a foundation for further biomass-energy research.In this study, the water samples collected from south part of the Yellow Sea. The microalgae were isolated and purified from the water samples using micro-pippette method. 240 microalgae strains were obtained in total, Then 8 algae strains with abundant biomass were selected after expanding culture, centrifugation and lyophilization. The strach, cellulose, total fat and soluble sugar content of the algae powder were quantified to sift the target energy microalgae species.The experimental results show that the oil content of Navicula sp. TW-2 reaches 41.33%, and Its growth rate is highest, biomass content is bigger. So the algae stain Navicula sp.NB-2 is suitable for processing biodiesel.The soluble sugar content of algae strains Nannochloropsis sp. NB-2 is 22.3%, the cellulose content is 9.61%, the starch content is 11%, and its biomass is biggest, which has a val ue for further study. Then applying the acquisition chlorella powder orthogonal test to determine the optimal conditions for microalgae pretreatment: 120 s blasting time, 4% concentration of sulfuric acid, 121 °C for 60 min hydrolysis. Under the conditions, the Nannochloropsis sp. NB-3 produced ethanol and the concentration reached 0.723 mg/100 ml. The ethanol yield is 5.75%, so the algae strains Nannochloropsis sp. NB-2 is the excellent algae strains to produce bio-fuel ethanol.