Utilization of recovered nitrogen from hydrothermal carbonization process by Arthrospira platensis
Abstract
In the context of sustainable cultivation of microalgae, the present study focused on the use of nitrogen from the hot-water extracted biomass residue of Arthrospira platensis by hydrothermal carbonization (HTC) and the sequential cultivation of the same alga with the HTC aqueous phase (AP). Nearly 90% of the nitrogen recovered from HTC into AP was in the organic form. Under nitrogen-limited condition with HTCAP as nitrogen source the yield and content of carbohydrate were enhanced by 21% and 15% respectively compared with that under the same nitrogen level provided by NaNO3, which entitled HTCAP for the substitution of conventional nitrate. In the same way pilot-scale cultivation of A. platensis in raceway ponds outdoors demonstrated that carbohydrate content of 43.8% DW and productivity of 10.3g/m(2)/d was achieved. Notably 54% of organic nitrogen in the HTCAP could be recycled by cultivation of pre-nitrogen starved A. platensis as seeds under nitrogen limitation.
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Some studies have reached 60% DW glycogen under N-limitation.
“The proportion of carbohydrates in Arthrospira platensis cells can reach up to 50% dry weight (DW) by optimizing the cultivation conditions [17]; some studies have even reached 60% DW of glycogen under the N-limitation condition [31].”
From Arthrospira platensis as a Feasible Feedstock for Bioethanol Production (2021) · cites this paper as [31]
Cites
Chlorophyll Fluorescence: A Probe of Photosynthesis In Vivo
Baker, N. R. (2008) · Annual Review of Plant Biology · doi:10.1146/annurev.arplant.59.032607.092759 · Cited by 4,672 · see citing works
Rapid colorimetric determination of nitrate in plant tissue by nitration of salicylic acid
Cataldo, D. A., Maroon, M., SCHRADER, L. E., & Youngs, V. L. (1975) · Communications in Soil Science and Plant Analysis · doi:10.1080/00103627509366547 · Cited by 3,337 · see citing works
A modified ninhydrin colorimetric analysis for amino acids
Rosen, H. (1957) · Archives of Biochemistry and Biophysics · doi:10.1016/0003-9861(57)90241-2 · Cited by 2,239 · see citing works
An outlook on microalgal biofuels
Wijffels, R. H., & Barbosa, M. J. (2010) · Science · doi:10.1126/science.1189003 · Cited by 1,886 · see citing works
Heterotrophic cultures of microalgae: Metabolism and potential products
Perez‐Garcia, O., Escalante, F. M. E., de‐Bashan, L. E., & Yoav Bashan, A. (2010) · Water Research · doi:10.1016/j.watres.2010.08.037 · Cited by 1,766 · see citing works
Microalgae biofuels: A critical review of issues, problems and the way forward
Lam, M. K., & Lee, K. T. (2011) · Biotechnology Advances · doi:10.1016/j.biotechadv.2011.11.008 · Cited by 938 · see citing works
Constraints to Commercialization of Algal Fuels
Chisti, Y. (2013) · Journal of Biotechnology · doi:10.1016/j.jbiotec.2013.07.020 · Cited by 719 · see citing works
López Barreiro, D., Prins, W., Ronsse, F., & Brilman, W. (2013) · Biomass and Bioenergy · doi:10.1016/j.biombioe.2012.12.029 · Cited by 695 · see citing works
Protein measurements of microalgal and cyanobacterial biomass
González–López, C. V., Cerón-García, M. C., Acién, F. G., Bustos, C. S., Yusuf Chisti, B., & Fernández-Sevilla, J. M. (2010) · Bioresource Technology · doi:10.1016/j.biortech.2010.04.077 · Cited by 649 · see citing works
A manual colorimetric procedure for measuring ammonium nitrogen in soil and plant Kjeldahl digests
Baethgen, W., & Alley, M. M. (1989) · Communications in Soil Science and Plant Analysis · doi:10.1080/00103628909368129 · Cited by 492 · see citing works
Biller, P., Ross, A. B., Skill, S. C., Lea-Langton, A., Balasundaram, B., Hall, C., Riley, R., & Llewellyn, C. A. (2012) · Algal Research · doi:10.1016/j.algal.2012.02.002 · Cited by 486 · see citing works
Gai, C., Zhang, Y., Chen, W.-T., Zhang, P., & Dong, Y. (2015) · Energy Conversion and Management · doi:10.1016/j.enconman.2015.02.056 · Cited by 297 · see citing works
Jena, U., Vaidyanathan, N., Chinnasamy, S., & Das, K. C. (2010) · Bioresource Technology · doi:10.1016/j.biortech.2010.09.111 · Cited by 268 · see citing works
Yao, C., Ai, J., Cao, X., Xue, S., & Zhang, W. (2012) · Bioresource Technology · doi:10.1016/j.biortech.2012.05.030 · Cited by 213 · see citing works
Microalgae growth on the aqueous phase from Hydrothermal Liquefaction of the same microalgae
Alba, L. G., Torri, C., Fabbri, D., Kersten, S. R. A., & Brilman, D. W. F. (2013) · Chemical Engineering Journal · doi:10.1016/j.cej.2013.04.097 · Cited by 208 · see citing works
Bioethanol Production by Carbohydrate-Enriched Biomass of Arthrospira (Spirulina) platensis
Μάρκου, Γ., Angelidaki, İ., Nerantzis, E. T., & Georgakakis, D. (2013) · Energies · doi:10.3390/en6083937 · Cited by 207 · see citing works
Nitrogen supply is an important driver of sustainable microalgae biofuel production
Peccia, J., HAZNEDAROĞLU, B. Z., Gutierrez, J., & Zimmerman, J. B. (2013) · Trends in biotechnology · doi:10.1016/j.tibtech.2013.01.010 · Cited by 201 · see citing works
Du, Z., Hu, B., Shi, A., Ma, X., Cheng, Y., Chen, P. L., Liu, Y., Lin, X., & Ruan, R. R. (2012) · Bioresource Technology · doi:10.1016/j.biortech.2012.09.062 · Cited by 163 · see citing works
Hydrothermal carbonization of microalgae II. Fatty acid, char, and algal nutrient products
Heilmann, S. M., Jader, L. R., Harned, L. A., Sadowsky, M. J., Schendel, F. J., Lefebvre, P. A., von Keitz, M. G., & Valentas, K. J. (2011) · Applied Energy · doi:10.1016/j.apenergy.2010.12.041 · Cited by 163 · see citing works
Hasunuma, T., Kikuyama, F., Matsuda, M., Aikawa, S., Izumi, Y., & Kondo, A. (2013) · Journal of Experimental Botany · doi:10.1093/jxb/ert134 · Cited by 160 · see citing works
Aikawa, S., Izumi, Y., Matsuda, F., Hasunuma, T., Chang, J.-S., & Kondo, A. (2012) · Bioresource Technology · doi:10.1016/j.biortech.2012.01.004 · Cited by 136 · see citing works
Cultivation of microalgae with recovered nutrients after hydrothermal liquefaction
López Barreiro, D., Bauer, M., Hornung, U., Posten, C., Kruse, A., & Prins, W. (2015) · Algal Research · doi:10.1016/j.algal.2015.03.007 · Cited by 133 · see citing works
Du, Z., Mohr, M., Ma, X., Cheng, Y., Lin, X., Liu, Y., Zhou, W., Chen, P. L., & Ruan, R. R. (2012) · Bioresource Technology · doi:10.1016/j.biortech.2012.06.007 · Cited by 129 · see citing works
Direct conversion of Spirulina to ethanol without pretreatment or enzymatic hydrolysis processes
Aikawa, S., Joseph, A., Yamada, R., Izumi, Y., Yamagishi, T., Matsuda, F., Kawai, H., Chang, J.-S., Hasunuma, T., & Kondo, A. (2013) · Energy & Environmental Science · doi:10.1039/c3ee40305j · Cited by 124 · see citing works
Μάρκου, Γ., Chatzipavlidis, I., & Georgakakis, D. (2012) · BioEnergy Research · doi:10.1007/s12155-012-9205-3 · Cited by 114 · see citing works
Spirulina (Arthrospira) industry in Inner Mongolia of China: current status and prospects
Lu, Y., Xiang, W., & Wen, Y.-H. (2010) · Journal of Applied Phycology · doi:10.1007/s10811-010-9552-4 · Cited by 86 · see citing works
Carrier-mediated Uptake of Arginine and Urea by Chlamydomonas reinhardtii
Kirk, D. L., & Kirk, M. M. (1978) · PLANT PHYSIOLOGY · doi:10.1104/pp.61.4.556 · Cited by 84 · see citing works
The use of hydrothermal carbonization to recycle nutrients in algal biofuel production
Levine, R. B., Sierra, C. O. S., Hockstad, R., Obeid, W., Hatcher, P. G., & Savage, P. E. (2013) · Environmental Progress & Sustainable Energy · doi:10.1002/ep.11812 · Cited by 73 · see citing works
Selvaratnam, T., Reddy, H., Muppaneni, T., Holguin, F. O., Nirmalakhandan, N., Lammers, P. J., & Deng, S. (2015) · Algal Research · doi:10.1016/j.algal.2015.07.007 · Cited by 50 · see citing works
Amino Acids, Peptides, and Proteins
Marshall, W. E. (1994) · Springer eBooks · doi:10.1007/978-1-4615-2073-3_12 · Cited by 35 · see citing works
Recycling Nutrients in Algae Biorefinery
Alba, L. G., Vos, M. P., Torri, C., Fabbri, D., Kersten, S. R. A., & Brilman, D. W. F. (2013) · ChemSusChem · doi:10.1002/cssc.201200988 · Cited by 31 · see citing works
Chi, L., Yao, C., Cao, X., & Xue, S. (2015) · Bioresource Technology · doi:10.1016/j.biortech.2015.10.059 · Cited by 27 · see citing works
Study of amino acids as nitrogen source in Chlamydomonas reinhardtii
Zuo, Z., Rong, Q., Chen, K., Yang, L., Chen, Z., Peng, K., Zhu, Y., Bai, Y., & Wang, Y. (2012) · Phycological Research · doi:10.1111/j.1440-1835.2012.00646.x · Cited by 20 · see citing works
Enhancement ofSpirulina biomass productivity by a protein hydrolysate
Singh, G., Kothari, R. M., Sharma, R. K., & Ramamurthy, V. (1995) · Applied Biochemistry and Biotechnology · doi:10.1007/bf02788098 · Cited by 18 · see citing works
Lochab, S., Kumar, P. A., & Raghuram, N. (2014) · Archives of Microbiology · doi:10.1007/s00203-014-0973-3 · Cited by 8 · see citing works
Flagged first, then by citations
Cited by
Sorted by citations
Nitrogen containing functional groups of biochar: An overview
Leng, L., Xu, S., Liu, R., Yu, T., Zhuo, X., Leng, S., Xiong, Q., & Huang, H. (2020) · Bioresource Technology · doi:10.1016/j.biortech.2019.122286 · Cited by 532 · see citing works
Leng, L., Li, J., Wen, Z., & Zhou, W. (2018) · Bioresource Technology · doi:10.1016/j.biortech.2018.01.121 · Cited by 251 · see citing works
Influence of temperature on nitrogen fate during hydrothermal carbonization of food waste
Wang, T., Zhai, Y., Zhu, Y., Peng, C. X., Xu, B., Wang, T., Li, C., & Zeng, G. (2017) · Bioresource Technology · doi:10.1016/j.biortech.2017.09.076 · Cited by 236 · see citing works
Recycling nutrients contained in human excreta to agriculture: Pathways, processes, and products
Harder, R., Wielemaker, R., Larsen, T. A., Zeeman, G., & Öberg, G. (2019) · Critical Reviews in Environmental Science and Technology · doi:10.1080/10643389.2018.1558889 · Cited by 227 · see citing works
Choudhary, P., Assemany, P. P., Naaz, F., Bhattacharya, A., Castro, J. D. S., do Couto, E. D. A., Calijuri, M. L., Pant, K. K., & Malik, A. (2020) · The Science of The Total Environment · doi:10.1016/j.scitotenv.2020.137961 · Cited by 154 · see citing works
Fate of Nitrogen during Hydrothermal Carbonization
Kruse, A., Koch, F., Stelzl, K., Wüst, D., & Zeller, M. (2016) · Energy & Fuels · doi:10.1021/acs.energyfuels.6b01312 · Cited by 135 · see citing works
Langone, M., & Basso, D. (2020) · International Journal of Environmental Research and Public Health · doi:10.3390/ijerph17186618 · Cited by 121 · see citing works
Leng, L., Zhang, W., Leng, S., Chen, J., Yang, L., Li, H., Jiang, S., & Huang, H. (2020) · The Science of The Total Environment · doi:10.1016/j.scitotenv.2020.142383 · Cited by 120 · see citing works
Dai, L., Yang, B., Li, H., Tan, F., Zhu, N., Zhu, Q., He, M., Ran, Y., & Hu, G. (2017) · Bioresource Technology · doi:10.1016/j.biortech.2017.07.016 · Cited by 99 · see citing works
Speciation and transformation of nitrogen for spirulina hydrothermal carbonization
Xiao, H., Zhai, Y., Xie, J., Wang, T., Wang, B., Li, S., & Li, C. (2019) · Bioresource Technology · doi:10.1016/j.biortech.2019.121385 · Cited by 89 · see citing works
Mixotrophic and heterotrophic growth of microalgae using acetate from different production processes
Tocca, G. P., Agostino, V., Menin, B., Tommasi, T., Fino, D., & Caprio, F. D. (2024) · Reviews in Environmental Science and Bio/Technology · doi:10.1007/s11157-024-09682-7 · Cited by 88 · see citing works
Kozyatnyk, I., Benavente, V., Weidemann, E., Gentili, F. G., & Jansson, S. (2023) · Scientific Reports · doi:10.1038/s41598-023-35331-0 · Cited by 74 · see citing works
Nutrients recovery and recycling in algae processing for biofuels production
Barbera, E., Bertucco, A., & Kumar, S. (2018) · Renewable and Sustainable Energy Reviews · doi:10.1016/j.rser.2018.03.004 · Cited by 72 · see citing works
Hydrothermal carbonization of Chinese fan palm
Yao, Z., & Ma, X. (2019) · Bioresource Technology · doi:10.1016/j.biortech.2019.02.130 · Cited by 63 · see citing works
Hydrothermal production of algal biochar for environmental and fertilizer applications: a review
Karthik, V., Kumar, P. S., Vo, D. N., Sindhu, J., Sneka, D., Subhashini, B., Saravanan, K., & Jeyanthi, J. (2020) · Environmental Chemistry Letters · doi:10.1007/s10311-020-01139-x · Cited by 59 · see citing works
Jiajia, Y., Hu, H., Wu, X., Wang, C., Zhou, T., Liu, Y., Ruan, R. R., & Zheng, H. (2019) · Bioresource Technology · doi:10.1016/j.biortech.2019.121420 · Cited by 53 · see citing works
Liu, Q., Yao, C., Sun, Y., Chen, W., Tan, H., Cao, X., Xue, S., & Yin, H. (2019) · Biotechnology for Biofuels · doi:10.1186/s13068-019-1470-3 · Cited by 52 · see citing works
Self-citationYao, C., Wu, P., Pan, Y., Lu, H., Chi, L., Meng, Y., Cao, X., Xue, S., & Yang, X. (2016) · Bioresource Technology · doi:10.1016/j.biortech.2016.05.110 · Cited by 48 · see citing works
Langone, M., Sabia, G., Petta, L., Zanetti, L. K., Leoni, P., & Basso, D. (2021) · Journal of Environmental Management · doi:10.1016/j.jenvman.2021.113561 · Cited by 47 · see citing works
Tarhan, S. Z., Koçer, A. T., Özçimen, D. B., & Gökalp, İ. (2020) · Journal of Water Process Engineering · doi:10.1016/j.jwpe.2020.101783 · Cited by 44 · see citing works
Assessing the environmental impact of resource recovery from dairy manure
Glover, C. J., McDonnell, A., Rollins, K., Hiibel, S. R., & Cornejo, P. K. (2023) · Journal of Environmental Management · doi:10.1016/j.jenvman.2022.117150 · Cited by 40 · see citing works
Li, C., Zhong, F., Liang, X., Xu, W., Yuan, Q., Niu, W., & HaiBo, M. (2023) · Energy Conversion and Management · doi:10.1016/j.enconman.2023.117192 · Cited by 32 · see citing works
Liu, H., Chen, Y., Yang, H., Hu, J., Wang, X., & Chen, H. (2022) · Algal Research · doi:10.1016/j.algal.2022.102759 · Cited by 30 · see citing works
Zhang, Q., Mu, K., Han, J. W., Qin, L., Zhao, B. Y., & Yi, L. (2023) · Energy · doi:10.1016/j.energy.2023.128012 · Cited by 28 · see citing works
Lang, Q., Luo, H., Li, Y., Li, D., Liu, Z., & Yang, T. (2019) · Sustainable Energy & Fuels · doi:10.1039/c9se00332k · Cited by 27 · see citing works
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Mustapha, S. I., & Isa, Y. M. (2025) · ChemBioEng Reviews · doi:10.1002/cben.202400035 · Cited by 27 · see citing works
Ran, W., Qi, X., Pan, Y., Xie, T., Zhang, Y., & Yao, C. (2020) · Industrial & Engineering Chemistry Research · doi:10.1021/acs.iecr.0c00398 · Cited by 25 · see citing works
Kassim, M. A. B. M., Kaus, N. H. M., Imam, S. S., Sagadevan, S., & Salaeh, S. (2023) · Inorganic Chemistry Communications · doi:10.1016/j.inoche.2023.111156 · Cited by 24 · see citing works
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Gonzalez Bautista, E., & Laroche, C. (2021) · Applied Sciences · doi:10.3390/app11156756 · Cited by 22 · see citing works
Zhang, Q., Wang, B., Feng, Y., Feng, Y., Li, J., Ding, S., He, H., & Xie, H. (2023) · Journal of Cleaner Production · doi:10.1016/j.jclepro.2023.136486 · Cited by 21 · see citing works
Ayaz, I., Rizwan, M., Ullman, J. L., Haroon, H., Qayyum, A., Ahmed, N., Elesawy, B. H., Askary, A. E., Gharib, A. F., & Ismail, K. A. (2022) · Polymers · doi:10.3390/polym14040715 · Cited by 19 · see citing works
Zhong, J., Zhu, W., Sun, J., Mu, B., Wang, X., Xue, Z., & Cao, J. (2023) · Chemosphere · doi:10.1016/j.chemosphere.2023.140504 · Cited by 18 · see citing works
Hupfauf, B., Süß, M., Dumfort, A., & Fuessl‐Le, H. (2016) · ChemBioEng Reviews · doi:10.1002/cben.201600008 · Cited by 18 · see citing works
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Asomaning, J., Omidghane, M., Chae, M. S., & Bressler, D. C. (2016) · Current Opinion in Green and Sustainable Chemistry · doi:10.1016/j.cogsc.2016.08.005 · Cited by 16 · see citing works
Niu, Z., Wang, Z., Wang, J., Huang, H., Liu, W., Zhu, H., YiFei, W., & Liu, X. (2021) · Environmental Science and Pollution Research · doi:10.1007/s11356-021-14697-6 · Cited by 14 · see citing works
Xie, H., Li, Q., Wang, M., Feng, Y., & Wang, B. (2024) · Journal of Hazardous Materials · doi:10.1016/j.jhazmat.2024.133946 · Cited by 14 · see citing works
Liu, J., Yao, C., Meng, Y., Cao, X., Wu, P., & Xue, S. (2018) · Biotechnology for Biofuels · doi:10.1186/s13068-018-1168-y · Cited by 14 · see citing works
Monogalactosyldiacylglycerols with High PUFA Content From Microalgae for Value-Added Products
Junpeng, J., Cao, X., Miao, Y., & Song, X. (2019) · Applied Biochemistry and Biotechnology · doi:10.1007/s12010-019-03159-y · Cited by 11 · see citing works
Chen, Z., Tan, L., Yang, B., Wu, J., Li, T., Wu, H., Wu, H., & Xiang, W. (2021) · Algal Research · doi:10.1016/j.algal.2021.102562 · Cited by 11 · see citing works
Kamal, R., Huang, Q., Li, Q., Chu, Y., Yu, X., Limtong, S., Xue, S., & Zhao, Z. K. (2021) · ACS Sustainable Chemistry & Engineering · doi:10.1021/acssuschemeng.1c02196 · Cited by 10 · see citing works
Zhang, Q., Mu, K., Zhao, B., & Yi, L. (2023) · Molecules · doi:10.3390/molecules28114408 · Cited by 5 · see citing works
Nutrient recovery by microalgae in aqueous product of hydrothermal carbonization of dairy manure
Silva, N. A., Glover, C. J., & Hiibel, S. R. (2023) · Cleaner Waste Systems · doi:10.1016/j.clwas.2023.100110 · Cited by 6 · see citing works
He, Y., He, Q., Pruski, K., Acharya, B., & Abbey, L. (2021) · Sustainable Agriculture Research · doi:10.5539/sar.v10n4p1 · Cited by 4 · see citing works
Fertile cities : Nutrient flows from new sanitation to urban agriculture
Wielemaker, R. (2019) · doi:10.18174/500300 · Cited by 3 · see citing works
Kabakcı, H., Koçer, A. T., & Balkanlı, D. (2026) · Journal of Applied Phycology · doi:10.1007/s10811-026-03888-8 · Cited by 2 · see citing works
Okoro, O. V., Santos-Bastilla, F. A., Amenaghawon, A. N., Nie, L., & Shavandi, A. (2025) · Process Safety and Environmental Protection · doi:10.1016/j.cherd.2025.11.007 · Cited by 1 · see citing works
Zhong, X., Wang, B., Sun, K., Xie, H., Tian, W., & Feng, Y. (2025) · Agricultural Ecology and Environment · doi:10.48130/aee-0025-0012 · Cited by 1 · see citing works
Improvement of nutritional quality of ruminant feed composed of soybean straw and ryegrass hay
Zen, C. K., Sartor, K. B., da Silva, R. V., Colla, L. M., & Reinehr, C. O. (2021) · Scientia Plena · doi:10.14808/sci.plena.2020.123103 · Cited by 1 · see citing works
- Authors
- Yao, C., Pan, Y., Lu, H., Wu, P., Meng, Y., Cao, X., & Xue, S.
- Affiliations
- Dalian Institute of Chemical Physics (CN)
- Corresponding author
- Xue, Song
- Venue
- Bioresource Technology
- Publisher
- Elsevier BV
- Published
- 2016-07
- Volume
- 212
- Pages
- 26-34
- ISSN
- 0960-8524 (ISSN-L)
- OpenAlex
- W2332626816
- Cited by
- 49
- References
- 35
- Citations by year
- 2026: 1 · 2025: 3 · 2024: 2 · 2023: 9 · 2022: 3 · 2021: 7 · 2020: 6 · 2019: 9 · 2018: 3 · 2017: 2 · 2016: 4
- FWCI
- 1.63
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Bioresource Technology (publishedVersion)
- PubMed (publishedVersion)
- Dalian Institute of Chemical Physics, CAS Institutional Repository (submittedVersion)
- Funders
- National Natural Science Foundation of China (41406177)
- Topics
- Physical Sciences › Energy › Renewable Energy, Sustainability and the Environment › Algal biology and biofuel production
- Physical Sciences › Earth and Planetary Sciences › Oceanography › Marine and coastal plant biology
- Physical Sciences › Earth and Planetary Sciences › Oceanography › Marine and coastal ecosystems
- Keywords
- Spirulina platensis, hydrothermal carbonization, nitrogen recovery, microalgae cultivation, nitrogen recycling, carbohydrate yield, nitrogen limitation, raceway ponds, biomass residues, organic nitrogen
- MeSH terms
- Carbon, Nitrates, Nitrogen, Biomass, Spirulina, Microalgae
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