Abstract
Mixotrophic cultivation of microalgae is an economical and environment-friendly approach to benefit biofuel production by increasing biomass. In this study, a novel strategy of gradient addition of carbon source is used in Chlamydomonas reinhardtii to obtain better biomass yields. Gradient strategy leads to low autophagy levels in microalgae, yielding the highest biomass of 9.42 ± 0.21 million cells/mL after 15 days of cultivation. This approach produces highest chlorophyll (36.17 ± 1.74 mg/mL) and carotenoids (8.85 ± 0.52 mg/mL). At 5 g/L sodium acetate, gradient mode results in increased starch accumulation at the stationary phase, while the single-stage produces the highest triacylglycerol (TAG) content at the log phase. TAG production is mediated by the combined action of high autophagy, de novo lipid synthesis, and starch degradation process. Increased autophagy indicates high oxidative stress in single-stage which results in liquid–liquid phase separation (LLPS) of TAG from the cytosol, forming lipid droplets (LDs) for cellular redox maintenance. The LD-cytosol phase coexistence boundary for single-stage reveals complete LD demixing from cytosol above a saturated volume fraction (φsat) due to LD growth. In the gradient mode, LDs are small and dispersed in the cytosol. These differences in LD size and density are attributed to the cell’s proteome and thermodynamic factors. For the first time, LLPS is observed to influence LD biogenesis in Chlamydomonas reinhardtii. Thus, this study unravels the metabolic regulation of mixotrophic biofuel production in Chlamydomonas, demonstrating gradient strategy as a promising approach for improving yields of various bioenergy products.
Similar content being viewed by others
Abbreviations
- NaAc:
-
Sodium acetate
- SS:
-
Single-stage
- Chl:
-
Chlorophyll
- TAG:
-
Triacylglycerol
- LD:
-
Lipid droplet
- LLPS:
-
Liquid–liquid phase separation
References
Khan MI, Shin JH, Kim JD (2018) The promising future of microalgae: current status, challenges, and optimization of a sustainable and renewable industry for biofuels, feed, and other products. Microb Cell Fact 17(1):1–21. https://doi.org/10.1186/s12934-018-0879-x
Demirbas MF (2010) Microalgae as a feedstock for biodiesel. Energy Educ Sci Technol Part A Energy Sci Res 25(1):31–43. https://doi.org/10.1007/978-3-642-17997-6_1
Paliwal C, Mitra M, Bhayani K, Bharadwaj SVV, Ghosh T, Dubey S, Mishra S (2017) Abiotic stresses as tools for metabolites in microalgae. Bioresour Technol 244:1216–1226. https://doi.org/10.1016/j.biortech.2017.05.058
Cakmak T, Angun P, Demiray YE, Ozkan AD, Elibol Z, Tekinay T (2012) Differential effects of nitrogen and sulfur deprivation on growth and biodiesel feedstock production of Chlamydomonas reinhardtii. Biotechnol Bioeng 109(8):1947–1957. https://doi.org/10.1002/bit.24474
Wahidin S, Idris A, Shaleh SRM (2013) The influence of light intensity and photoperiod on the growth and lipid content of microalgae Nannochloropsis sp. Bioresour Technol 129:7–11. https://doi.org/10.1016/j.biortech.2012.11.032
Patil S, Pandit R, Lali A (2017) Photosynthetic acclimation of Chlorella saccharophila to heat stress. Phycol Res 65(2):160–165. https://doi.org/10.1111/pre.12171
Minhas AK, Hodgson P, Barrow CJ, Adholeya A (2016) A review on the assessment of stress conditions for simultaneous production of microalgal lipids and carotenoids. Front Microbiol 7(MAY):1–19. https://doi.org/10.3389/fmicb.2016.00546
Lin TS, Wu JY (2015) Effect of carbon sources on growth and lipid accumulation of newly isolated microalgae cultured under mixotrophic condition. Bioresour Technol 184:100–107. https://doi.org/10.1016/j.biortech.2014.11.005
Moon M, Kim CW, Park WK, Yoo G, Choi YE, Yang JW (2013) Mixotrophic growth with acetate or volatile fatty acids maximizes growth and lipid production in Chlamydomonas reinhardtii. Algal Res 2(4):352–357. https://doi.org/10.1016/j.algal.2013.09.003
Candido C, Lombardi AT (2020) Mixotrophy in green microalgae grown on an organic and nutrient rich waste. World J Microbiol Biotechnol 36(2). https://doi.org/10.1007/s11274-020-2802-y
Park WK, Moon M, Kwak MS, Jeon S, Choi GG, Yang JW, Lee B (2014) Use of orange peel extract for mixotrophic cultivation of Chlorella vulgaris: increased production of biomass and FAMEs. Bioresour Technol 171:343–349. https://doi.org/10.1016/j.biortech.2014.08.109
Singh H, Shukla MR, Chary KVR, Rao BJ (2014) Acetate and bicarbonate assimilation and metabolite formation in Chlamydomonas reinhardtii: A13C-NMR study. PLoS One 9(9). https://doi.org/10.1371/journal.pone.0106457
Puzanskiy R, Shavarda A, Romanyuk D, Shishova M (2021) The role of trophic conditions in the regulation of physiology and metabolism of Chlamydomonas reinhardtii during batch culturing. J Appl Phycol 33(5):2897–2908. https://doi.org/10.1007/s10811-021-02510-3
Liyanaarachchi VC, Premaratne M, Ariyadasa TU, Nimarshana PHV, Malik A (2021) Two-stage cultivation of microalgae for production of high-value compounds and biofuels: A review. Algal Res 57(May):102353. https://doi.org/10.1016/j.algal.2021.102353
Aziz MMA, Kassim KA, Shokravi Z, Jakarni FM, Lieu HY, Zaini N, Tan LS, Islam S and Shokravi H (2020) Two-stage cultivation strategy for simultaneous increases in growth rate and lipid content of microalgae: a review. Renew. Sustain. Energy Rev. 119(November 2019):109621. https://doi.org/10.1016/j.rser.2019.109621.
Yen HW, Chang JT (2013) A two-stage cultivation process for the growth enhancement of Chlorella vulgaris. Bioprocess Biosyst Eng 36(11):1797–1801. https://doi.org/10.1007/s00449-013-0922-6
Chen JH, Kato Y, Matsuda M, Chen CY, Nagarajan D, Hasunuma T, Kondo A, Chang JS (2021) Lutein production with Chlorella sorokiniana MB-1-M12 using novel two-stage cultivation strategies – metabolic analysis and process improvement. Bioresour Technol 334(April):125200. https://doi.org/10.1016/j.biortech.2021.125200
Chen CY, Liu CC (2018) Optimization of lutein production with a two-stage mixotrophic cultivation system with Chlorella sorokiniana MB-1. Bioresour Technol 262(April):74–79. https://doi.org/10.1016/j.biortech.2018.04.024
Li X, Wang M, Liao X, Chen H, Dai Y, Chen B (2015) Two stages of N-deficient cultivation enhance the lipid content of microalga Scenedesmus sp. J Am Oil Chem Soc 92(4):503–512. https://doi.org/10.1007/s11746-015-2613-8
Ho SH, Nakanishi A, Ye X, Chang XJS, Hara K, Hasunuma T, Kondo A (2014) Optimizing biodiesel production in marine Chlamydomonas sp JSC4 through metabolic profiling and an innovative salinity-gradient strategy. Biotechnol Biofuels 7(1):1–16. https://doi.org/10.1186/1754-6834-7-97
Chapman SP, Paget CM, Johnson GN, Schwartz JM (2015) Flux balance analysis reveals acetate metabolism modulates cyclic electron flow and alternative glycolytic pathways in Chlamydomonas reinhardtii. Front Plant Sci 6(JUNE):1–14. https://doi.org/10.3389/fpls.2015.00474
Ran W, Wang H, Liu Y, Qi M, Xiang Q, Yao C, Zhang Y, Lan X (2019) Storage of starch and lipids in microalgae: biosynthesis and manipulation by nutrients. Bioresour Technol 291(June):121894. https://doi.org/10.1016/j.biortech.2019.121894
Goncalves EC, Wilkie AC, Kirst M, Rathinasabapathi B (2016) Metabolic regulation of triacylglycerol accumulation in the green algae: identification of potential targets for engineering to improve oil yield. Plant Biotechnol J 14(8):1649–1660. https://doi.org/10.1111/pbi.12523
Li-Beisson Y, Beisson F, Riekhof W (2015) Metabolism of acyl-lipids in Chlamydomonas reinhardtii. Plant J 82(3):504–522. https://doi.org/10.1111/tpj.12787
Fan J, Yan C, Andre C, Shanklin J, Schwender J, Xu C (2012) Oil accumulation is controlled by carbon precursor supply for fatty acid synthesis in Chlamydomonas reinhardtii. Plant Cell Physiol 53(8):1380–1390. https://doi.org/10.1093/pcp/pcs082
Li-Beisson Y, Kong F, Wang P, Lee Y, Kang BH (2021) The disassembly of lipid droplets in Chlamydomonas. New Phytol 231(4):1359–1364. https://doi.org/10.1111/nph.17505
Henne M, Goodman JM, Hariri H (2020) Spatial compartmentalization of lipid droplet biogenesis Biochim. Biophys Acta Mol Cell Biol Lipids 1865(1):158499. https://doi.org/10.1016/j.bbalip.2019.07.008
Walther TC, Chung J, Farese RV (2017) Lipid droplet biogenesis. Annu Rev Cell Dev Biol 33(1):491–510. https://doi.org/10.1146/annurev-cellbio-100616-060608
Hyman AA, Weber CA, Jülicher F (2014) Liquid-liquid phase separation in biology. Annu Rev Cell Dev Biol 30:39–58. https://doi.org/10.1146/annurev-cellbio-100913-013325
Kim HS, Guzman AR, Thapa HR, Devarenne TP, Han A (2016) A droplet microfluidics platform for rapid microalgal growth and oil production analysis. Biotechnol Bioeng 113(8):1691–1701. https://doi.org/10.1002/bit.25930
Khan MU, Mitchell K (1987) Chlorophylls carotenoids 148:350–382
Black SK, Smolinski SL, Feehan C, Pienkos PT, Jarvis EE, Laurens LML (2013) New method for discovery of starch phenotypes in growing microalgal colonies. Anal Biochem 432(2):71–73. https://doi.org/10.1016/j.ab.2012.09.018
Chen W, Zhang C, Song L, Sommerfeld M, Hu Q (2009) A high throughput Nile red method for quantitative measurement of neutral lipids in microalgae. J Microbiol Methods 77(1):41–47. https://doi.org/10.1016/j.mimet.2009.01.001
Kou Z, Bei S, Sun J, Pan J (2013) Fluorescent measurement of lipid content in the model organism Chlamydomonas reinhardtii. J Appl Phycol 25(6):1633–1641. https://doi.org/10.1007/s10811-013-0011-x
Bell SA, Shen C, Brown A and Hunt AG (2016) Experimental genome-wide determination of RNA polyadenylation in Chlamydomonasreinhardtii.https://doi.org/10.1371/journal.pone.0146107
Lv H, Qu G, Qi X, Lu L, Tian C, Ma Y (2013) Transcriptome analysis of Chlamydomonas reinhardtii during the process of lipid accumulation. Genomics 101(4):229–237. https://doi.org/10.1016/j.ygeno.2013.01.004
Pérez-Pérez M, Couso I, Heredia-Martínez L, Crespo J (2017) Monitoring autophagy in the model green microalga Chlamydomonas reinhardtii 6(4):36. https://doi.org/10.3390/cells6040036
Zhang Z, Sun D (2017) Cheng KW and Chen F (2018) Inhibition of autophagy modulates astaxanthin and total fatty acid biosynthesis in Chlorella zofingiensis under nitrogen starvation. Bioresour Technol 247:610–615. https://doi.org/10.1016/j.biortech.2017.09.133
Kajikawa M, Fukuzawa H (2020) Algal autophagy is necessary for the regulation of carbon metabolism under nutrient deficiency. Front Plant Sci 11(February):1–6. https://doi.org/10.3389/fpls.2020.00036
Zhao L, Dai J and Wu Q (2014) Autophagy-like processes are involved in lipid droplet degradation in Auxenochlorella protothecoides during the heterotrophy-autotrophy transition. Front. Plant Sci. 5(AUG):1–12 https://doi.org/10.3389/fpls.2014.00400.
Upadhyaya S and Nagar N (2018) Short title : corresponding author : 2018.
Johnson X, Alric J (2013) Central carbon metabolism and electron transport in Chlamydomonas reinhardtii: metabolic constraints for carbon partitioning between oil and starch. Eukaryot Cell 12(6):776–793. https://doi.org/10.1128/EC.00318-12
Ho SH, Nakanishi A, Kato Y, Yamasaki H, Chang JS, Misawa N, Hirose Y, Minagawa J, Hasunuma T and Kondo A (2017) Dynamic metabolic profiling together with transcription analysis reveals salinity-induced starch-To-lipid biosynthesis in alga Chlamydomonas sp. JSC4. Sci. Rep. 7(April):1–7. https://doi.org/10.1038/srep45471.
Saito Y, Kimura W (2021) Roles of phase separation for cellular redox maintenance 12(July):1–15. https://doi.org/10.3389/fgene.2021.691946
Maneechote W and Cheirsilp B (2021) Stepwise-incremental physicochemical factors induced acclimation and tolerance in oleaginous microalgae to crucial outdoor stresses and improved properties as biodiesel feedstocks. Bioresour. Technol. 328(December 2020):124850. https://doi.org/10.1016/j.biortech.2021.124850.
Heifetz PB, Förster B, Osmond CB, Giles LJ, Boynton JE (2000) Effects of acetate on facultative autotrophy in Chlamydomonas reinhardtii assessed by photosynthetic measurements and stable isotope analyses. Plant Physiol 122(4):1439–1445. https://doi.org/10.1104/pp.122.4.1439
Boyle NR, Morgan JA (2009) Flux balance analysis of primary metabolism in Chlamydomonas reinhardtii. BMC Syst Biol 3:1–14. https://doi.org/10.1186/1752-0509-3-4
Fields FJ (March 2017) Ostrand JT and Mayfield SP (2018) Fed-batch mixotrophic cultivation of Chlamydomonas reinhardtii for high-density cultures. Algal Res 33:109–117. https://doi.org/10.1016/j.algal.2018.05.006
Bogaert KA, Perez E, Rumin J, Giltay A, Carone M, Coosemans N, Radoux M, Eppe G, Levine RD, Remacle F and Remacle C (2019) Metabolic, physiological, and transcriptomics analysis of batch cultures of the green microalga Chlamydomonas grown on different acetate concentrations. 8(11):.1–21. https://doi.org/10.3390/cells8111367.
Smith RT, Gilmour DJ (2018) The influence of exogenous organic carbon assimilation and photoperiod on the carbon and lipid metabolism of Chlamydomonas reinhardtii. Algal Res 31:2018. https://doi.org/10.1016/j.algal.2018.01.020
Chouhan N, Devadasu E, Yadav RM and Subramanyam R (2022) Autophagy Induced Accumulation of Lipids in pgrl1 and pgr5 of Chlamydomonas reinhardtii Under High Light. Front. Plant Sci. 12(January) https://doi.org/10.3389/fpls.2021.752634
Roach T (1827) Sedoud A and Krieger-Liszkay A (2013) Acetate in mixotrophic growth medium affects photosystem II in Chlamydomonas reinhardtii and protects against photoinhibition. Biochim Biophys Acta - Bioenerg 10:1183–1190. https://doi.org/10.1016/j.bbabio.2013.06.004
Puzanskiy RK, Romanyuk DA, Shishova MF (2020) Shift in expression of the genes of primary metabolism and chloroplast transporters in Chlamydomonas reinhardtii under different trophic conditions. Russ J Plant Physiol 67(5):867–878. https://doi.org/10.1134/S102144372005012X
Pang N, Gu X, Chen S, Kirchhoff H, Lei H, Roje S (2019) Exploiting mixotrophy for improving productivities of biomass and co-products of microalgae. Renew Sustain Energy Rev 112(June):450–460. https://doi.org/10.1016/j.rser.2019.06.001
Xie Y, Li J, Ma R, Ho SH, Shi X, Liu L, Chen J (2019) Bioprocess operation strategies with mixotrophy/photoinduction to enhance lutein production of microalga Chlorella sorokiniana FZU60. Bioresour Technol 290(June):121798. https://doi.org/10.1016/j.biortech.2019.121798
Pérez-Pérez ME, Couso I, Crespo JL (2012) Carotenoid deficiency triggers autophagy in the model green alga Chlamydomonas reinhardtii. Autophagy 8(3):376–388. https://doi.org/10.4161/auto.8.3.18864
Couso I, Pérez-Pérez ME, Martínez-Force E, Kim HS, He Y, Umen JG, Crespo JL (2018) Autophagic flux is required for the synthesis of triacylglycerols and ribosomal protein turnover in Chlamydomonas. J Exp Bot 69(6):1355–1367. https://doi.org/10.1093/jxb/erx372
Li Y, Han D, Hu G, Sommerfeld M, Hu Q (2010) Inhibition of starch synthesis results in overproduction of lipids in Chlamydomonas reinhardtii. Biotechnol Bioeng 107(2):258–268. https://doi.org/10.1002/bit.22807
Ramanan R, Kim BH, Cho DH, Ko SR, Oh HM, Kim HS (2013) Lipid droplet synthesis is limited by acetate availability in starchless mutant of Chlamydomonas reinhardtii. FEBS Lett 587(4):370–377. https://doi.org/10.1016/j.febslet.2012.12.020
Zoni V, Khaddaj R, Campomanes P, Thiam R, Schneiter R and Vanni S (2020) Lipid droplet biogenesis is driven by liquid-liquid phase separation. SSRN Electron. J.1–30. https://doi.org/10.2139/ssrn.3526890.
Lu Y, Wang X, Balamurugan S, Yang WD, Liu JS, Dong HP, Li HY (2017) Identification of a putative seipin ortholog involved in lipid accumulation in marine microalga Phaeodactylum tricornutum. J Appl Phycol 29(6):2821–2829. https://doi.org/10.1007/s10811-017-1173-8
Yu W, Ansari W, Schoepp NG, Hannon MJ, Mayfield SP and Burkart MD (2011) Modifications of the metabolic pathways of lipid and triacylglycerol production in microalgae.1–11.
Moser BR (2009) Biodiesel production, properties, and feedstocks. Vitr Cell Dev Biol - Plant 45(3):229–266. https://doi.org/10.1007/s11627-009-9204-z
Acknowledgements
D.B. acknowledges the funding received from Gujarat State Biotechnology Mission, Gujarat, India (GSBTM/JDR&D/608/2020/462). S.P. acknowledges University Grants Commission, UGC for fellowship and contingency. Authors are grateful for the infrastructure support to the Department of Microbiology and Biotechnology Centre from the DST-FIST program of Govt. of India. S.P., P.K., and S.D. acknowledge Ms. Juliya Thomas and Ms. Janvi Jain (Dept. of Microbiology and Biotechnology Centre, The M.S. University of Baroda) for their help in designing and validating primers and for other support in qPCR-based study.
Funding
This work was supported by funds from Gujarat State Biotechnology Mission, Gujarat, India (GSBTM/JDR&D/608/2020/462).
Author information
Authors and Affiliations
Contributions
Conceptualization: Shubhangi Pandey, Archana Gattupalli, Debjani Bagchi. Methodology: Shubhangi Pandey, Archana Gattupalli, Debjani Bagchi. Investigation: Shubhangi Pandey, Palak Kumar, Swarnali Dasgupta. Formal analysis: Shubhangi Pandey, Palak Kumar, Swarnali Dasgupta, Debjani Bagchi. Writing — original draft preparation: Shubhangi Pandey, Debjani Bagchi. Writing — review and editing: Shubhangi Pandey, Palak Kumar, Swarnali Dasgupta, Archana Gattupalli, Debjani Bagchi. Funding acquisition: Archana Gattupalli, Debjani Bagchi. Resources: Archana Gattupalli, Debjani Bagchi. Supervision: Archana Gattupalli, Debjani Bagchi.
Corresponding authors
Ethics declarations
Competing Interests
The authors declare no competing interests.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary Information
Below is the link to the electronic supplementary material.
Rights and permissions
About this article
Cite this article
Pandey, S., Kumar, P., Dasgupta, S. et al. Gradient Strategy for Mixotrophic Cultivation of Chlamydomonas reinhardtii: Small Steps, a Large Impact on Biofuel Potential and Lipid Droplet Morphology. Bioenerg. Res. 16, 163–176 (2023). https://doi.org/10.1007/s12155-022-10454-w
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12155-022-10454-w