Tixing Algae And Single-needle Growth And Study Of Fat Synthesis Factors

Green algae can be utilized to produce clean renewable biodiesel, an alternative to traditional fossil fuels, which may alleviate environmental pollution and energy shortage problem. Lots of studies focused on factors influencing the proliferation of green algae, while few researches investigated how different types and concentration of nutrient elements influencing their oil production. In this article, experiments are designed to investigate multiple factors influencing the growth of Monoraphidium sp. zp-2and Kirchneriella sp. zp-1by AGP (algae growth potential) test, and the effects of nutrient elements on growth and oil production of two strains of microalgae are disscussed.The AGP test investigate the concentration dependent effects of different nutrient ions, including Mg2+、Ca2+、Fe3+、Zn2+、Mn2+、NO3-、HPO42-, and different plant hormones, including indoleacetic acid (IAA), naphthalene acetic acid (NAA) and6-benzylamino purine (6-BA), on growth and oil production of two green aglae strains, Kirchneriella sp. zp-1and Monoraphidium sp. zp-2The AGP test results also indicate the optimal concentration of different nutrient ions and hormones for both strains, repectively. For the Kirchneriella sp.zp-1Kirchneriella sp. zp-1strain, the optimal concentration of Mg2+, Ca2+, Fe3+, Zn2+, Mn2+, NO3-, HPO42-, IAA, NAA, and6-BA are:0.5mmol/L, and0.33mmol/L, and0.035mmol/L, and5×10-3mmol/L, and9.6×10-3mmol/L,3.3mmol/L, and4×10-3mmol/L, and11.4×10-3mmol/L, and4.3×10-3mmol/L, and4.4×10-3mmol/L, respectively; for the Monoraphidium sp. zp-2strain, the optimal concentration of Mg2+, Ca2+, Fe3+, Zn2+, Mn2+, NO3-, HPO42-,IAA, NAA, and6-BA are:1mmol/L, and0.99mmol/L, and0.035mmol/L, and5×10-3mmol/L, and9.6×10-3mmol/L,2mmol/L, and0.4×10-3mmol/L, and4.57×10-3mmol/L, and10.8×10-3mmol/L, and4.4×10-3mmol/L, respectively.The experiment result unravals:(1) The nutrient elements investigated affects the total lipid production of Kirchneriella sp. zp-1Kirchneriella sp. zp-1strain:compared to control experiment, when the concentration of Mg2+reached to1.5mmol/L, total lipid yield had an increase of6%; when the concentration of Ca2+reached to0.33mmol/L, total lipid yield had an increase of18.36%; when the concentration of Fe3+reached to0.021mmol/L, total lipid yield had an increase of9.44%; when the concentration of Zn2+reached to5×10-3mmol/L, total lipid yield had an increase of13.11%; when the concentration of Mn2+reached to9.6×10-3mmol/L, total lipid yield had an increase of12.26%; when the concentration of NO3-reached to3.3mmol/L, total lipid yield had an increase of19.29%; when the concentration of HPO42-reached to0.4×10-3mmol/L, total lipid yield had an increase of25.62%; when the concentrations of IAA reached to4.57×10-3mmol/L, total lipid yield had an increase of11.38%; when the concentration of NAA reached to8.1×10-3mmol/L, total lipid yield had an increase of4.62%; when the concentration of6-BA reached to6.7×10-3mmol/L, total lipid yield had an increase of7.36%;(2) The nutrient elements investigated also affects the total lipid production of Monoraphidium sp. zp-2Monoraphidium sp. zp-2strain:compared to control experiment, when the concentration of Mg2+reached to0.5mmol/L, total lipid yield had an increase of6.25%; when the concentration of Ca2+reached to0.24mmol/L, total lipid yield had an increase of8.8%; when the concentration of Fe3+reached to0.017mmol/L, total lipid yield had an increase of15.95%; when the concentration of Zn2+reached to1Ox10-3mmol/L, total lipid yield had an increase of16.82%; when the concentration of Mn2+reached to9.6×10-3mmol/L, total lipid yield had an increase of8.86%; when the concentration of NO3-reached to3.3mmol/L, and total lipid yield had an increase of16.54%; when the concentration of HPO42-reached to4×10-3mmol/L, total lipid yield had an increase of15.38%; when the concentration of IAA reached to4.57×10-3mmol/L, total lipid yield had an increase of12.42%; when concentration of NAA reached to8.1×10-3mmol/L, and total lipid yield had an increase of3.6%; when the concentration of6-BA reached to3.5×10-3mmol/L, total lipid yield had an increase of3.96%;(3) The experiment results showed that the Mg2+, Fe3+, Zn2+, Mn2+, NO3-and HPO42-are significant factors on algae growth and total lipid yield. The orthogonal experiments indicated that Zn2+is a significant factor influencing total lipid yield and unsaturated fatty acid yield of Kirchneriella sp. zp-1strain. Zn2+and Mg2+are the significant factors affecting total lipid yield of Monoraphidium sp. zp-2strain. On the unsaturated fatty acid yield of Monoraphidium sp. zp-2strain, the intiutive analysis indicated that Zn, Mn, Fe are significant factors, while the Zn in the variance analysis showed that only Zn is significant factor, which is not on accord with the the intiutive analysis results. Unsaturated fatty acids, especilally polyunsaturatedfatty acids, have high oxidization and self-aggregation potential. Byoptimizing the nutirent factors, the pecentiage of unsaturated fatty acids isable to be minimized.(4) The experiments results indicated that algae Kirchneriella sp. zp-1and Monoraphidium sp. zp-2have the ability to grow in water with several nutrient elements and synthesis lipid, which has the protential to be utilized in biodiesel production and purification of eutrophic water.