Abstract
Euglena gracilis (E. gracilis) is a unicellular microalga with various applications in medicine, agriculture, aquaculture, health supplement, and jet fuel production. Euglena possibly solves population growth and exhaustion of fossil resources. Efficient cell harvesting is needed for the industry, and the gravity sedimentation method is low cost and does not require any equipment, although it has low efficiency. This study showed that the gravity sedimentation of E. gracilis cells is improved by cultivation in the presence of ethanol (EtOH). The gravity sedimentation of E. gracilis cells cultivated under 0.5% or 1.0% EtOH conditions was faster than that cultivated without EtOH. The mean calculated cell diameter was also found to be largest in cells cultivated under 0.5% or 1.0% EtOH conditions compared to that in cells cultivated without EtOH. Intracellular paramylon content, cell shapes, and motility differed between cells cultivated under 0.5% or 1.0% EtOH conditions and in the absence of EtOH. The results suggest that E. gracilis cultivation with EtOH leads to increased cell productivity, paramylon production, and efficient cell harvesting.
Key points
• Euglena gracilis is an edible microalga producing value-added metabolites.
• Ethanol addition upregulates E. gracilis growth and paramylon accumulation.
• Gravity sedimentation is accelerated by ethanol-grown E. gracilis cells.
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References
Alkarawi MA, Caldwell GS, Lee JG (2018) Continuous harvesting of microalgae biomass using foam flotation. Algal Res 36:125–138. https://doi.org/10.1016/j.algal.2018.10.018
Babel S, Takizawa S (2010) Microfiltration membrane fouling and cake behavior during algal filtration. Desalination 261(1–2):46–51. https://doi.org/10.1016/j.desal.2010.05.038
Baicha Z, Salar-García MJ, Ortiz-Martínez VM, Hernández-Fernández FJ, De Los Ríos AP, Labjar N, Lotfi E, Elmahi M (2016) A critical review on microalgae as an alternative source for bioenergy production: a promising low cost substrate for microbial fuel cells. Fuel Process Technol 154:104–116. https://doi.org/10.1016/j.fuproc.2016.08.017
Barsanti L, Vismara R, Passarelli V, Gualtieri P (2001) Paramylon (β-1, 3-glucan) content in wild type and WZSL mutant of Euglena gracilis. Effects of growth conditions. J Appl Phycol 13(1):59–65. https://doi.org/10.1023/A:1008105416065
Bentley RW, Mannan SA, Wheeler SJ (2007) Assessing the date of the global oil peak: the need to use 2P reserves. Energy Policy 35(12):6364–6382. https://doi.org/10.1016/j.enpol.2007.08.001
Brennan L, Owende P (2010) Biofuels from microalgae—a review of technologies for production, processing, and extractions of biofuels and co-products. Renew Sustain Energ Rev 14(2):557–577. https://doi.org/10.1016/j.rser.2009.10.009
Brown JS (1980) Absorption and fluorescence spectra of chlorophyll-proteins isolated from Euglena gracilis. Biochim Biophys Acta Bioenerg 591(1):9–21. https://doi.org/10.1016/0005-2728(80)90216-9
Clarke AE, Stone BA (1960) Structure of the paramylon from Euglena gracilis. Biochim Biophys Acta 44:161–163. https://doi.org/10.1016/0006-3002(60)91534-1
Cleveland JS (1995) Regional models for phytoplankton absorption as a function of chlorophyll a concentration. J Geophys Res Oceans 100(C7):13333–13344. https://doi.org/10.1029/95JC00532
Cramer M, Myers J (1952) Growth and photosynthetic characteristics of Euglena gracilis. Archiv Mikrobiol 17(1):384–402. https://doi.org/10.1007/BF00410835
Dubois M, Gilles KA, Hamilton JK, Rebers PT, Smith F (1956) Colorimetric method for determination of sugars and related substances. Anal Chem 28(3):350–356. https://doi.org/10.1021/ac60111a017
Durante G, Basset A, Stanca E, Roselli L (2019) Allometric scaling and morphological variation in sinking rate of phytoplankton. J Phycol 55(6):1386–1393. https://doi.org/10.1111/jpy.12916
Falchuk KH, Fawcett DW, Vallee BL (1975) Role of zinc in cell division of Euglena gracilis. J Cell Sci 17(1):57–78. https://doi.org/10.1242/jcs.17.1.57
Gong Y, Jiang M. (2011) Biodiesel production with microalgae as feedstock: from strains to biodiesel. Biotechnol Lett Jul 33(7):1269–12684. https://doi.org/10.1007/s10529-011-0574-z
Gualtieri P, Barsanti L, Passarelli V (1988) Chitosan as flocculant for concentrating Euglena gracilis cultures. Ann Inst Pasteur Microbiol 139(6):717–726. https://doi.org/10.1016/0769-2609(88)90076-2
Häder DP, Lebert M (1998) The photoreceptor for phototaxis in the photosynthetic flagellate Euglena gracilis. Photochem Photobiol 68(3):260–265. https://doi.org/10.1111/j.1751-1097.1998.tb09679.x
Inui H, Ishikawa T, Tamoi M (2017) Wax ester fermentation and its application for biofuel production. Adv Exp Med Biol 269–283. https://doi.org/10.1007/978-3-319-54910-1_13
Ishikawa M, Nomura T, Tamaki S, Ozasa K, Suzuki T, Toyooka K, Hirota K, Yamada K, Suzuki K, Mochida K (2022) CRISPR/Cas9-mediated generation of non-motile mutants to improve the harvesting efficiency of mass-cultivated Euglena gracilis. Plant Biotechnol J 20(11):2042–2044. https://doi.org/10.1111/pbi.13904
Jasso-Chávez R, Moreno-Sánchez R (2003) Cytosol–mitochondria transfer of reducing equivalents by a lactate shuttle in heterotrophic Euglena. Eur J Biochem 270(24):4942–4951. https://doi.org/10.1046/j.1432-1033.2003.03896.x
Jasso-Chávez R, García-Cano I, Marín-Hernández Á, Mendoza-Cózatl D, Rendón JL, Moreno-Sánchez R (2005) The bacterial-like lactate shuttle components from heterotrophic Euglena gracilis. Biochim Biophys Acta 1709(2):181–190. https://doi.org/10.1016/j.bbabio.2005.07.007
Kanda Y (2013) Investigation of the freely available easy-to-use software ‘EZR’ for medical statistics. Bone Marrow Transplant 48(3):452–458. https://doi.org/10.1038/bmt.2012.244
Kiss JZ, Richard ET (1988) A comparative study of the storage carbohydrate granules from Euglena (Euglenida) and Pavlova (Prymnesiida) 1, 2. J Protozool 35(2):237–241. https://doi.org/10.1111/j.1550-7408.1988.tb04331.x
Koley S, Prasad S, Bagchi SK, Mallick N (2017) Development of a harvesting technique for large-scale microalgal harvesting for biodiesel production. RSC Adv 7(12):7227–7237. https://doi.org/10.1039/C6RA27286J
Kottuparambil S, Thankamony RL, Agusti S (2019) Euglena as a potential natural source of value-added metabolites. A Review Algal Res 37:154–159. https://doi.org/10.1016/j.algal.2018.11.024
Kusmic C, Barsanti L, Di Lascio N, Faita F, Evangelista V, Gualtieri P (2018) Anti-fibrotic effect of paramylon nanofibers from the WZSL mutant of Euglena gracilis on liver damage induced by CCl4 in mice. J Funct Foods 46:538–545. https://doi.org/10.1016/j.jff.2018.05.021
Lakio S, Heinämäki J, Yliruusi J (2010) Colorful Drying. Aaps Pharmscitech 11(1):46–53. https://doi.org/10.1208/s12249-009-9351-x
Lutz VA, Sathyendranath S, Head EJH (1996) Absorption coefficient of phytoplankton: regional variations in the North Atlantic. Mar Ecol Prog Ser 135:197–213. https://doi.org/10.3354/meps135197
Marchessault RH, Deslandes Y (1979) Fine structure of (1→ 3)-β-d-glucans: curdlan and paramylon. Carbohydr Res 75:231–242. https://doi.org/10.1016/S0008-6215(00)84642-X
Milledge JJ, Heaven S (2013) A review of the harvesting of micro-algae for biofuel production. Rev Environ Sci Bio/technol 12(2):165–178. https://doi.org/10.1007/s11157-012-9301-z
Mortensen A, Skibsted LH (1997) Importance of carotenoid structure in radical-scavenging reactions. J Agric Food Chem 45(8):2970–2977. https://doi.org/10.1021/jf970010s
Nurdogan Y, Oswald WJ (1996) Tube settling of high-rate pond algae. Water Sci Technol 33(7):229–241. https://doi.org/10.1016/0273-1223(96)00358-7
Rodríguez-Zavala JS, Ortiz-Cruz MA, Moreno-Sanchez R (2006) Characterization of an aldehyde dehydrogenase from Euglena gracilis. J Eukaryotic Microbiol 53(1):36–42. https://doi.org/10.1111/j.1550-7408.2005.00070.x
Russo R, Barsanti L, Evangelista V, Frassanito AM, Longo V, Pucci L, Penno G, Gualtieri P (2017) Euglena gracilis paramylon activates human lymphocytes by upregulating pro-inflammatory factors. Food Sci Nutr 5(2):205–214. https://doi.org/10.1002/fsn3.383
Scartazza A, Picciarelli P, Mariotti L, Curadi M, Barsanti L, Gualtieri P (2017) The role of Euglena gracilis paramylon in modulating xylem hormone levels, photosynthesis and water-use efficiency in Solanum lycopersicum L. Physiol Plant 161(4):486–501. https://doi.org/10.1111/ppl.12611
Shen Y, Yuan W, Pei ZJ, Wu Q, Mao E (2009) Microalgae mass production methods. Trans ASABE 52(4):1275–1287. https://doi.org/10.13031/2013.27771
Stephens E, Ross IL, Mussgnug JH, Wagner LD, Borowitzka MA, Posten C, Kruse O, Hankamer B (2010) Future prospects of microalgal biofuel production systems. Trends Plant Sci 15(10):554–564. https://doi.org/10.1016/j.tplants.2010.06.003
Takaichi S (2011) Carotenoids in algae: distributions, biosynthesis and functions. Mar Drugs 9(6):1101–1118. https://doi.org/10.3390/md9061101
Thomas AL (1983) Regulation of cell shape in Euglena gracilis: I Involvement of the biological clock, respiration, photosynthesis, and cytoskeleton. Plant Physiol 71(4):719–730. https://doi.org/10.1104/pp.71.4.719
Tomita Y, Takeya M, Suzuki K, Nitta N, Higuchi C, Marukawa-Hashimoto Y, Osanai T (2019) Amino acid excretion from Euglena gracilis cells in dark and anaerobic conditions. Algal Res 37:169–177. https://doi.org/10.1016/j.algal.2018.11.017
Vismara R, Vestri S, Frassanito AM, Barsanti L, Gualtieri P (2004) Stress resistance induced by paramylon treatment in Artemia sp. J Appl Phycol 16(1):61–67. https://doi.org/10.1023/B:JAPH.0000019113.77013.0d
Vogel K, Hemmersbach-Krause R, Kühnel C, Häder D (1993) Swimming behavior of the unicellular flagellate, Euglena gracilis, in simulated and real microgravity. Microgravity Sci Technol 4:232–237. https://elib.dlr.de/26797/
Wang L, Pan B, Gao Y, Li C, Ye J, Yang L, Chen Y, Hu Q, Zhang X (2019) Efficient membrane microalgal harvesting: pilot-scale performance and techno-economic analysis. J Cleaner Prod 218:83–95. https://doi.org/10.1016/j.jclepro.2019.01.321
Wu M, Li J, Qin H, Lei A, Zhu H, Hu Z, Wang J (2020) Pre-concentration of microalga Euglena gracilis by alkalescent pH treatment and flocculation mechanism of Ca3(PO4)2, Mg3 (PO4)2, and derivatives. Biotechnol Biofuels 13(1):1–13. https://doi.org/10.1186/s13068-020-01734-8
Yokojima S, Takashima R, Miyahara T (2015) Effects of particle shape on settling behavior of particle cluster. J Japan Soc Civil Eng Ser A2 71(2):I_719-I_730. https://doi.org/10.2208/jscejam.71.I_719
Zimba PV, Moeller PD, Beauchesne K, Lane HE, Triemer RE (2010) Identification of euglenophycin–a toxin found in certain euglenoids. Toxicon 55(1):100–104. https://doi.org/10.1016/j.toxicon.2009.07.004
Acknowledgements
The authors would like to thank Enago (www.enago.jp) for the English-language review.
Funding
This work was supported by the following grants to T.O.: JSPS KAKENHI Grant-in-Aid for Scientific Research (B) (grant number 20H02905) and JST-ALCA of the Japan Science and Technology Agency (grant number JPMJAL1306). This study was also funded by euglena Co., Ltd. (Tokyo, Japan). However, the funding sources did not affect the interpretation of the results of this study.
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Y.T. designed the study, performed the experiments, analyzed the data, and wrote the manuscript. Kosuke S. helped run some of the experiments. C.T. and Kengo S. helped design the study. T.O. analyzed the data and wrote the manuscript with Y.T.
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Takashi Osanai declares that this study was funded by euglena Co., Ltd.; however, the funding sources did not affect the interpretation of the results of this study. The other authors declare that they have no conflict of interest.
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Takahashi, Y., Shimamoto, K., Toyokawa, C. et al. Gravity sedimentation of eukaryotic algae Euglena gracilis accelerated by ethanol cultivation. Appl Microbiol Biotechnol 107, 3021–3032 (2023). https://doi.org/10.1007/s00253-023-12476-6
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DOI: https://doi.org/10.1007/s00253-023-12476-6