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Primo TARDC, Vargas LB, Alves RD, de Farias Neves F, Skoronski E. New insights into chicken processing wastewater treatment: the role of the microalgae Parachlorella kessleri on nitrogen removal. ENVIRONMENTAL TECHNOLOGY 2024:1-13. [PMID: 39052955 DOI: 10.1080/09593330.2024.2381643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Accepted: 07/09/2024] [Indexed: 07/27/2024]
Abstract
Microalgal Technologies have recently been employed as an alternative treatment for high nitrogen content wastewater. Nitrogen is an essential nutrient for microalgae growth, and its presence in wastewater may be an alternative source to synthetic medium, contributing to a circular economy. This study aimed to investigate the effect of using Parachlorella kessleri cultivated in wastewater from the thermal processing of chicken meat. Experiments were performed to obtain the ideal sampling site, inoculum dosage, and contact time. P. kessleri had better growth in the sample from the settling basin. Nitrogen removal was 95% (0,15 mg TNK/107 cells) in 9 days, and the final nitrogen concentration was lower than 20 mg/L, and the nitrate concentration was lower than 1 mg/L. However, during the third cycle in the kinetic assay, there was a decline in the microalgae growth, occasioned by the accumulation of nitrite (38,4 mg/L) in the inside of the cell. The study demonstrated that nitrogen concentration is directly related to the cell growth of the algae. Parachlorella kessleri efficiently removed nitrogen from chicken meat thermal processing wastewater and is a potential option for tertiary treatment and valorisation of such effluent as a nitrogen source.
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Affiliation(s)
- Thais Agda R da C Primo
- Department of Environmental and Sanitary Engineering, Laboratory for Water and Waste Treatment, Santa Catarina State University, Lages, Brazil
| | - Luana Búrigo Vargas
- Department of Environmental and Sanitary Engineering, Laboratory for Water and Waste Treatment, Santa Catarina State University, Lages, Brazil
| | - Rafaela Dexcheimer Alves
- Department of Environmental and Sanitary Engineering, Laboratory for Water and Waste Treatment, Santa Catarina State University, Lages, Brazil
| | - Fabio de Farias Neves
- Department of Fisheries Engineering and Biological Sciences, Laboratory of Alga Cultivation and Biotechnology, Santa Catarina State University, Laguna, Brazil
| | - Everton Skoronski
- Department of Environmental and Sanitary Engineering, Laboratory for Water and Waste Treatment, Santa Catarina State University, Lages, Brazil
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Schoeters F, Spit J, Azizah RN, Van Miert S. Pilot-Scale Cultivation of the Snow Alga Chloromonas typhlos in a Photobioreactor. Front Bioeng Biotechnol 2022; 10:896261. [PMID: 35757813 PMCID: PMC9218667 DOI: 10.3389/fbioe.2022.896261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 05/02/2022] [Indexed: 11/13/2022] Open
Abstract
The most studied and cultivated microalgae have a temperature optimum between 20 and 35°C. This temperature range hampers sustainable microalgae growth in countries with colder periods. To overcome this problem, psychrotolerant microalgae, such as the snow alga Chloromonas typhlos, can be cultivated during these colder periods. However, most of the research work has been carried out in the laboratory. The step between laboratory-scale and large-scale cultivation is difficult, making pilot-scale tests crucial to gather more information. Here, we presented a successful pilot-scale growth test of C. typhlos. Seven batch mode growth periods were compared during two longer growth tests in a photobioreactor of 350 L. We demonstrated the potential of this alga to be cultivated at colder ambient temperatures. The tests were performed during winter and springtime to compare ambient temperature and sunlight influences. The growth and CO2 usage were continuously monitored to calculate the productivity and CO2 fixation efficiency. A maximum dry weight of 1.082 g L-1 was achieved while a maximum growth rate and maximum daily volumetric and areal productivities of 0.105 d-1, 0.110 g L-1 d-1, and 2.746 g m-2 d-1, respectively, were measured. Future tests to optimize the cultivation of C. typhlos and production of astaxanthin, for example, will be crucial to explore the potential of biomass production of C. typhlos on a commercial scale.
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Affiliation(s)
- Floris Schoeters
- Radius, Thomas More University of Applied Sciences, Geel, Belgium
| | - Jornt Spit
- Radius, Thomas More University of Applied Sciences, Geel, Belgium
| | - Rahmasari Nur Azizah
- Radius, Thomas More University of Applied Sciences, Geel, Belgium.,I-BioStat, Data Science Institute, Hasselt University, Hasselt, Belgium
| | - Sabine Van Miert
- Radius, Thomas More University of Applied Sciences, Geel, Belgium
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Sarkar S, Manna MS, Bhowmick TK, Gayen K. Effect of different illumination patterns on the growth and biomolecular synthesis of isolated Chlorella Thermophila in a 50 L pilot-scale photobioreactor. Process Biochem 2021. [DOI: 10.1016/j.procbio.2021.07.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Towards industrial production of microalgae without temperature control: The effect of diel temperature fluctuations on microalgal physiology. J Biotechnol 2021; 336:56-63. [PMID: 34146615 DOI: 10.1016/j.jbiotec.2021.06.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 06/10/2021] [Accepted: 06/11/2021] [Indexed: 11/20/2022]
Abstract
Regions that offer high levels of sunlight are ideal to produce microalgae. However, as a result of high light intensities, the temperature in photobioreactors can reach temperatures up to 50 °C. Control of temperature is essential to avoid losses on biomass productivity but should be limited to a minimum to avoid high energy requirements for cooling. Our objective is to develop a production process in which cooling is not required. We studied the behaviour of thermotolerant microalgae Picochlorum sp. (BPE23) under four diel temperature regimes, with peak temperatures from 30 °C up to a maximum of 47.5 °C. The highest growth rate of 0.17 h-1 was obtained when applying a daytime peak temperature of 40 °C. Operating photobioreactors in tropical regions, with a maximal peak temperature of 40 °C, up from 30 °C, reduces microalgae production costs by 26.2 %, based on simulations with a pre-existing techno-economic model. Cell pigmentation was downregulated under increasingly stressful temperatures. The fatty acid composition of cell membranes was altered under increasing temperatures to contain shorter fatty acids with a higher level of saturation. Our findings show that the level of temperature control impacts the biomass yield and composition of the microalgae.
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Growth and fatty acid content of Rhodomonas sp. under day:night cycles of light and temperature. ALGAL RES 2020. [DOI: 10.1016/j.algal.2020.102034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Xiao Y, Guo J, Zhu H, Muhammad A, Deng H, Hu Z, Wu Q. Inhibition of glucose assimilation in Auxenochlorella protothecoides by light. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:146. [PMID: 32831906 PMCID: PMC7437033 DOI: 10.1186/s13068-020-01787-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Accepted: 08/12/2020] [Indexed: 05/06/2023]
Abstract
BACKGROUND The yield of microalgae biomass is the key to affect the accumulation of fatty acids. A few microalgae can assimilate organic carbon to improve biomass yield. In mixotrophic cultivation, microalgae can use organic carbon source and light energy simultaneously. The preference of the main energy source by microalgae determines the biomass yield. Auxenochlorella protothecoides is an oleaginous mixotrophic microalga that can efficiently assimilate glucose and accumulate a large amount of biomass and fatty acids. The current study focused on the effect of light on the growth and glucose assimilation of A. protothecoides. RESULTS In this study, we found that the uptake and metabolism of glucose in A. protothecoides could be inhibited by light, resulting in a reduction of biomass growth and lipid accumulation. We employed comparative proteomics to study the influence of light on the regulation of glucose assimilation in A. protothecoides. Proteomics revealed that proteins involving in gene translation and photosynthesis system were up-regulated in the light, such as ribulose-phosphate 3-epimerase and phosphoribulokinase. Calvin cycle-related proteins were also up-regulated, suggesting that light may inhibit glucose metabolism by enhancing the production of glyceraldehyde-3-phosphate (G3P) in the Calvin cycle. In addition, the redox homeostasis-related proteins such as thioredoxin reductase were up-regulated in the light, indicating that light may regulate glucose uptake by changing the redox balance. Moreover, the increase of NADH levels and redox potential of the medium under illumination might inhibit the activity of the glucose transport system and subsequently reduce glucose uptake. CONCLUSIONS A theoretical model of how glucose assimilation in A. protothecoides is negatively influenced by light was proposed, which will facilitate further studies on the complex mechanisms underlying the transition from autotrophy to heterotrophy for improving biomass accumulation.
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Affiliation(s)
- Yibo Xiao
- Guangdong Technology Research Center for Marine Algal Bioengineering, Guangdong Key Laboratory of Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 People’s Republic of China
- Key Laboratory of Optoelectronic Devices and Systems of the Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Jianying Guo
- Key Laboratory of Industrial Biocatalysis of the Ministry of Education and Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing, 100084 People’s Republic of China
| | - Huachang Zhu
- Guangdong Technology Research Center for Marine Algal Bioengineering, Guangdong Key Laboratory of Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Anwar Muhammad
- Guangdong Technology Research Center for Marine Algal Bioengineering, Guangdong Key Laboratory of Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 People’s Republic of China
- Key Laboratory of Optoelectronic Devices and Systems of the Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Haiteng Deng
- Key Laboratory of Industrial Biocatalysis of the Ministry of Education and Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing, 100084 People’s Republic of China
| | - Zhangli Hu
- Guangdong Technology Research Center for Marine Algal Bioengineering, Guangdong Key Laboratory of Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 People’s Republic of China
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Longhua Innovation Institute for Biotechnology, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Qingyu Wu
- Guangdong Technology Research Center for Marine Algal Bioengineering, Guangdong Key Laboratory of Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 People’s Republic of China
- Key Laboratory of Industrial Biocatalysis of the Ministry of Education and Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing, 100084 People’s Republic of China
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Lv H, Wang QE, Qi B, Liu C, Xiao Y, Jia S. Physiological and Metabolic Responses of a Novel Dunaliella salina Strain to Myo-inositol 1. JOURNAL OF PHYCOLOGY 2020; 56:687-698. [PMID: 31975508 DOI: 10.1111/jpy.12973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 01/02/2020] [Indexed: 06/10/2023]
Abstract
Dunaliella salina is well known for its ability to accumulate large amounts of β-carotene. Myo-inositol (MI) enhances the biomass production of D. salina, but the underlying mechanisms were unclear. The present study showed that the concentration of exogenous MI decreased gradually and reached a constant level at the 4th day of cultivation. MI enhanced the contents of total colored carotenoids and the activity of photosystem II. Metabolic profiles were significantly changed after the addition of exogenous MI, as revealed by multivariate statistical analysis. The metabolites could be categorized into four groups based on the relative levels in different samples. Exogenous MI increased the levels of most detected sugars, amino acids, and total saturated and unsaturated fatty acids. Based on the physiological and metabolic analyses, a hypothetical growth-promoting model that MI promotes the growth of D. salina TG by increasing the levels of key metabolites and possibly enhancing photosynthesis, was proposed. This study provides valuable information for understanding the growth-promoting mechanisms of MI in D. salina from the metabolic perspective.
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Affiliation(s)
- Hexin Lv
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, China
- Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, Tianjin University of Science & Technology, Tianjin, 300457, China
| | - Qiao-E Wang
- Beijing Key Lab of Plant Resource Research and Development, Beijing Technology and Business University, Beijing, 100048, China
| | - Bingbing Qi
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, China
| | - Cuihua Liu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, China
| | - Yupeng Xiao
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, China
| | - Shiru Jia
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, China
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Oostlander P, van Houcke J, Wijffels R, Barbosa M. Optimization of Rhodomonas sp. under continuous cultivation for industrial applications in aquaculture. ALGAL RES 2020. [DOI: 10.1016/j.algal.2020.101889] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Roles J, Yarnold J, Wolf J, Stephens E, Hussey K, Hankamer B. Charting a development path to deliver cost competitive microalgae-based fuels. ALGAL RES 2020. [DOI: 10.1016/j.algal.2019.101721] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Influence of Photoperiods on Microalgae Biofilm: Photosynthetic Performance, Biomass Yield, and Cellular Composition. ENERGIES 2019. [DOI: 10.3390/en12193724] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Microalgae have immense potential as biological sources to produce biofuels and high-value biomolecules. Biofilm-based microalgae cultivation has attracted much interest recently because of its high biomass productivity, reduced water use, and low cost of harvesting. This study aimed to understand the effect of photoperiod on three microalgae biofilms, including Nannochloris oculata, Chlorella sp., and Chlorella pyrenoidosa. The examined photoperiods were 3:3 s, 5:5 s, 30:30 min, 12:12 h (light-period-to-dark-period ratio), and continuous lighting. By determining the maximum quantum yield and relative electron transport rate of photosystem II, we found that photoperiods on the seconds scale improved photosynthetic performance of microalgae biofilm. Biomass yield and lipid content of these three microalgae cultured under the photoperiod with the seconds scale increased by 11%–24% and 7%–22%, respectively, compared with those cultured under continuous lighting. In addition, the photoperiods of 3:3 s, 5:5 s, 30:30 min, and 12:12 h were beneficial for protein synthesis. These results have important implications in establishing suitable light regimes for microalgae biofilm-based cultivation systems.
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Torres-Romero I, Kong F, Légeret B, Beisson F, Peltier G, Li-Beisson Y. Chlamydomonas cell cycle mutant crcdc5 over-accumulates starch and oil. Biochimie 2019; 169:54-61. [PMID: 31563539 DOI: 10.1016/j.biochi.2019.09.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Accepted: 09/23/2019] [Indexed: 10/25/2022]
Abstract
The use of algal biomass for biofuel production requires improvements in both biomass productivity and its energy density. Green microalgae store starch and oil as two major forms of carbon reserves. Current strategies to increase the amount of carbon reserves often compromise algal growth. To better understand the cellular mechanisms connecting cell division to carbon storage, we examined starch and oil accumulation in two Chlamydomonas mutants deficient in a gene encoding a homolog of the Arabidopsis Cell Division Cycle 5 (CDC5), a MYB DNA binding protein known to be involved in cell cycle in higher plants. The two crcdc5 mutants (crcdc5-1 and crcdc5-2) were found to accumulate significantly higher amount of starch and oil than their corresponding parental lines. Flow cytometry analysis on synchronized cultures cultivated in a diurnal light/dark cycle revealed an abnormal division of the two mutants, characterized by a prolonged S/M phase, therefore demonstrating its implication in cell cycle in Chlamydomonas. Taken together, these results suggest that the energy saved by a slowdown in cell division is used for the synthesis of reserve compounds. This work highlights the importance in understanding the interplay between cell cycle and starch/oil homeostasis, which should have a critical impact on improving lipid/starch productivity.
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Affiliation(s)
- Ismael Torres-Romero
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, 13108, Saint Paul-Lez-Durance, France
| | - Fantao Kong
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, 13108, Saint Paul-Lez-Durance, France
| | - Bertrand Légeret
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, 13108, Saint Paul-Lez-Durance, France
| | - Fred Beisson
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, 13108, Saint Paul-Lez-Durance, France
| | - Gilles Peltier
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, 13108, Saint Paul-Lez-Durance, France
| | - Yonghua Li-Beisson
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, 13108, Saint Paul-Lez-Durance, France.
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Qi F, Pei H, Mu R, Ma G, Wu D, Han Q. Characterization and optimization of endogenous lipid accumulation in Chlorella vulgaris SDEC-3M ability to rapidly accumulate lipid for reversing nightly lipid loss. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:151. [PMID: 31236138 PMCID: PMC6580531 DOI: 10.1186/s13068-019-1493-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Accepted: 06/09/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND During inevitable light/dark cycle, lipid productivity of outdoor microalgae photoautotrophic cultivation is lowered by nightly biomass and lipid loss. To minimize, or even reverse the nightly lipid loss, it was expected that lipid accumulation would not cease, even if at night. Without relying on photosynthesis and organic matter in media, endogenous lipid accumulation that consumes energy and carbon sources derived from cells themselves, namely endogenous accumulation, is the only way for lipid production. The main aims of the present study was to characteristic endogenously accumulated lipid, confirm feasibility to reverse nightly lipid loss, and determine optimal conditions and its quality suitability for biodiesel feedstock production under stress conditions. RESULTS Chlorella vulgaris SDEC-3M ability to rapidly accumulated lipid under stress conditions was cultivated for 12 h in darkness, and the effects of various conditions on lipid accumulation and biomass loss were analyzed. Under non-stress conditions, lipid contents dropped. Under certain stress conditions, conversely, the lipid contents were substantially improved so that net nightly endogenous lipid accumulation was observed. Under the optimal conditions (aeration mode with 0.10 vvm and 15% CO2, 5-10 mg L-1 of NO3 --N, 30-35 °C, approximate 2500 mg L-1 of biomass), the lipid content was doubled and increased lipid was approximately 180 mg L-1. Among stress conditions, N-deficiency had the most significant effect on endogenous lipid accumulation, and the optimum results were characterized under relatively low-N concentrations. Higher consistency between loss in carbohydrate and gain in lipid confirmed accumulated lipid endogenously conversed from carbohydrate. Based on the analyses of fatty acids profiles and prediction of kinematic viscosity, specific gravity, cloud point, cetane number and iodine value, it was confirmed that the quality of lipid obtained under optimal conditions complied with biodiesel quality standards. CONCLUSION Via triggering endogenous lipid accumulation by stress conditions, even in darkness, SDEC-3M can synthesize enough lipid suitable for biodiesel feedstock. It implies that the lipid accumulation phase in two-phase strategy can be scheduled at night, and following biomass production stage in light, which should be a solution to improve the lipid yield and quality of large-scale outdoor photoautotrophic microalgae cultivation for biodiesel production.
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Affiliation(s)
- Feng Qi
- School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan, 250101 China
- Shandong Provincial Engineering Centre on Environmental Science and Technology, Jinan, 250061 China
- Shandong Co-innovation Center of Green Building, Jinan, 250101 China
| | - Haiyan Pei
- Shandong Provincial Engineering Centre on Environmental Science and Technology, Jinan, 250061 China
- School of Environmental Science and Engineering, Shandong University, Qingdao, 266237 China
| | - Ruimin Mu
- School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan, 250101 China
- Shandong Co-innovation Center of Green Building, Jinan, 250101 China
| | - Guixia Ma
- School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan, 250101 China
| | - Daoji Wu
- School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan, 250101 China
| | - Qiang Han
- Jinan Urban Construction Group Co., Ltd, Jinan, 250031 China
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Kato Y, Fujihara Y, Vavricka CJ, Chang JS, Hasunuma T, Kondo A. Light/dark cycling causes delayed lipid accumulation and increased photoperiod-based biomass yield by altering metabolic flux in oleaginous Chlamydomonas sp. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:39. [PMID: 30828384 PMCID: PMC6383270 DOI: 10.1186/s13068-019-1380-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 02/16/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Light/dark cycling is an inevitable outdoor culture condition for microalgal biofuel production; however, the influence of this cycling on cellular lipid production has not been clearly established. The general aim of this study was to determine the influence of light/dark cycling on microalgal biomass production and lipid accumulation. To achieve this goal, specific causative mechanisms were investigated using a metabolomics approach. Laboratory scale photoautotrophic cultivations of the oleaginous green microalga Chlamydomonas sp. JSC4 were performed under continuous light (LL) and light/dark (LD) conditions. RESULTS Lipid accumulation and carbohydrate degradation were delayed under the LD condition compared with that under the LL condition. Metabolomic analysis revealed accumulation of phosphoenolpyruvate and decrease of glycerol 3-phosphate under the LD condition, suggesting that the imbalance of these metabolites is a source of delayed lipid accumulation. When accounting for light dosage, biomass yield under the LD condition was significantly higher than that under the LL condition. Dynamic metabolic profiling showed higher levels of lipid/carbohydrate anabolism (including production of 3-phosphoglycerate, fructose 6-phosphate, glucose 6-phosphate, phosphoenolpyruvate and acetyl-CoA) from CO2 under the LD condition, indicating higher CO2 fixation than that of the LL condition. CONCLUSIONS Photoperiods define lipid accumulation and biomass production, and light/dark cycling was determined as a critical obstacle for lipid production in JSC4. Conversions of phosphoenolpyruvate to pyruvate and 3-phosphoglycerate to glycerol 3-phosphate are the candidate rate-limiting steps responsible for delayed lipid accumulation. The accumulation of substrates including ribulose 5-phosphate could be explained by the close relationship of increased biomass yield with enhanced CO2 fixation. The present study investigated the influence of light/dark cycling on lipid production by direct comparison with continuous illumination for the first time, and revealed underlying metabolic mechanisms and candidate metabolic rate-limiting steps during light/dark cycling. These findings suggest promising targets to metabolically engineer improved lipid production.
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Affiliation(s)
- Yuichi Kato
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, 657-8501 Japan
| | - Yusuke Fujihara
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, 657-8501 Japan
| | - Christopher J. Vavricka
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, 657-8501 Japan
| | - Jo-Shu Chang
- Department of Chemical Engineering, National Cheng Kung University, Tainan, 701 Taiwan
- Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan, 701 Taiwan
| | - Tomohisa Hasunuma
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, 657-8501 Japan
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, 657-8501 Japan
| | - Akihiko Kondo
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, 657-8501 Japan
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, 657-8501 Japan
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, 657-8501 Japan
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Sivakaminathan S, Hankamer B, Wolf J, Yarnold J. High-throughput optimisation of light-driven microalgae biotechnologies. Sci Rep 2018; 8:11687. [PMID: 30076312 PMCID: PMC6076246 DOI: 10.1038/s41598-018-29954-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 07/19/2018] [Indexed: 12/18/2022] Open
Abstract
Microalgae biotechnologies are rapidly developing into new commercial settings. Several high value products already exist on the market, and systems development is focused on cost reduction to open up future economic opportunities for food, fuel and freshwater production. Light is a key environmental driver for photosynthesis and optimising light capture is therefore critical for low cost, high efficiency systems. Here a novel high-throughput screen that simulates fluctuating light regimes in mass cultures is presented. The data was used to model photosynthetic efficiency (PEµ, mol photon-1 m2) and chlorophyll fluorescence of two green algae, Chlamydomonas reinhardtii and Chlorella sp. Response surface methodology defined the effect of three key variables: density factor (Df, 'culture density'), cycle time (tc, 'mixing rate'), and maximum incident irradiance (Imax). Both species exhibited a large rise in PEµ with decreasing Imax and a minimal effect of tc (between 3-20 s). However, the optimal Df of 0.4 for Chlamydomonas and 0.8 for Chlorella suggested strong preferences for dilute and dense cultures respectively. Chlorella had a two-fold higher optimised PEµ than Chlamydomonas, despite its higher light sensitivity. These results demonstrate species-specific light preferences within the green algae clade. Our high-throughput screen enables rapid strain selection and process optimisation.
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Affiliation(s)
- Shwetha Sivakaminathan
- The University of Queensland, Institute for Molecular Bioscience, 306 Carmody Road, St Lucia, Australia
| | - Ben Hankamer
- The University of Queensland, Institute for Molecular Bioscience, 306 Carmody Road, St Lucia, Australia
| | - Juliane Wolf
- The University of Queensland, Institute for Molecular Bioscience, 306 Carmody Road, St Lucia, Australia.
| | - Jennifer Yarnold
- The University of Queensland, Institute for Molecular Bioscience, 306 Carmody Road, St Lucia, Australia.
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