Jingjing Zhan1, Yu Hong1, Hongying Hu2. 1. Beijing Key Laboratory for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, P.R. China. 2. Environmental Simulation and Pollution Control State Key Joint Laboratory, School of Environment, Tsinghua University, Beijing 100084, P.R. China.
Abstract
Microalgae are being researched for their potential as attractive biofuel feedstock, particularly for their lipid production. For maximizing biofuel production, it is necessary to explore the effects of environmental factors on algal lipid-producing potential. In this study, the effects of nitrogen (N) sources (NO2-N, NO3-N, urea-N, NH4-N, and N-deficiency) and carbon-to-nitrogen ratios (C/N= 0, 1.0, 3.0, and 5.0) on algal lipid-producing potential of Chlorella sp. HQ were investigated. The results showed that for Chlorella growth and lipid accumulation potential, NO2-N was the best amongst the nitrogen sources, and NO3-N and urea-N also contributed to algal growth and lipid accumulation potential, but NH4-N and N-deficiency instead caused inhibitory effects. Moreover, the results indicated that algal lipid-producing potential was related to C/N ratios. With NO2-N treatment and carbon addition (C/N = 1.0, 3.0, and 5.0), total lipid yield was enhanced by 12.96-20.37%, but triacylglycerol (TAG) yields decreased by 25.52-94.31%. As for NO3-N treatment, carbon addition led to a 17.82-57.43%/ 25.86-82.67% reduction of total lipid/TAG yields. When NH4-N was used as the nitrogen source, total lipid/TAG yields were increased by 46.67-113.33%/28.99-74.76% with carbon addition. The total lipid/TAG yields of urea-N treatment varied with C/N ratios. Overall, the highest TAG yield (TAG yield: 38.75 ± 5.21 mg/l; TAG content: 44.16 ± 4.35%) was achieved under NO2-N treatment without carbon addition (C/N = 0), the condition that had merit for biofuel production.
Microalgae are being researched for their potential as attractive biofuel feedstock, particularly for their lipid production. For maximizing biofuel production, it is necessary to explore the effects of environmental factors on algal n class="Chemical">lipid-producing potential. In this study, the effects of nitrogen (N) sources (NO2-N, NO3-N, urea-N, NH4-N, and N-deficiency) and carbon-to-nitrogen ratios (C/N= 0, 1.0, 3.0, and 5.0) on algal lipid-producing potential of Chlorella sp. HQ were investigated. The results showed that for Chlorella growth and lipid accumulation potential, NO2-N was the best amongst the nitrogen sources, and NO3-N and urea-N also contributed to algal growth and lipid accumulation potential, but NH4-N and N-deficiency instead caused inhibitory effects. Moreover, the results indicated that algal lipid-producing potential was related to C/N ratios. With NO2-N treatment and carbon addition (C/N = 1.0, 3.0, and 5.0), total lipid yield was enhanced by 12.96-20.37%, but triacylglycerol (TAG) yields decreased by 25.52-94.31%. As for NO3-N treatment, carbon addition led to a 17.82-57.43%/ 25.86-82.67% reduction of total lipid/TAG yields. When NH4-N was used as the nitrogen source, total lipid/TAG yields were increased by 46.67-113.33%/28.99-74.76% with carbon addition. The total lipid/TAG yields of urea-N treatment varied with C/N ratios. Overall, the highest TAG yield (TAG yield: 38.75 ± 5.21 mg/l; TAG content: 44.16 ± 4.35%) was achieved under NO2-N treatment without carbon addition (C/N = 0), the condition that had merit for biofuel production.
Authors: Aline D Batista; Rinamara M Rosa; Mariana Machado; Alan S Magalhães; Bárbara A Shalaguti; Priscilla F Gomes; Lidiane Covell; Marcelo G M V Vaz; Wagner L Araújo; Adriano Nunes-Nesi Journal: Metabolomics Date: 2019-02-28 Impact factor: 4.290