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Tran HD, Ong BN, Ngo VT, Tran DL, Nguyen TC, Tran-Thi BH, Do TT, Nguyen TML, Nguyen XH, Melkonian M. New Angled Twin-layer Porous Substrate Photobioreactors for Cultivation of Nannochloropsis oculata. Protist 2022; 173:125914. [PMID: 36270076 DOI: 10.1016/j.protis.2022.125914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 08/25/2022] [Accepted: 09/25/2022] [Indexed: 12/30/2022]
Abstract
An angled twin-layer porous substrate photobioreactor (TL-PSBR) using LED light was designed to cultivate Nannochloropsis oculata. Flocculation and sedimentation by modification of pH to 11 were determined as the optimal method for harvesting the N. oculata inoculum. The following optimised parameters were found: tilt angle 15°, Kraft 220 g m-2 paper as substrate material, initial inoculum density of 12.5 g m-2, 140 µmol photons m-2 s-1 light intensity, and a light/dark cycle of 6:6 (h). Test cultivation for 14 days was performed under optimised conditions. The total dried biomass standing crop was 75.5 g m-2 growth area with an average productivity of 6.3 g m-2 d-1, the productivity per volume of used culture medium was 126.2 mg/L d-1, total lipid content 21.9% (w/w), and the highest productivity of total lipids was 1.33 g m-2 d-1. The dry algal biomass contained 3% eicosapentaenoic acid (w/w), 3.7% palmitoleic acid (w/w), and 513 mg kg-1 vitamin E. The optimisation of N. oculata cultivation on an angled TL-PSBR system yielded promising results, and applications for commercial products need to be further explored.
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Affiliation(s)
- Hoang-Dung Tran
- Faculty of Biology and Environment, Ho Chi Minh City University of Food Industry, 140 Le Trong Tan Street, Tay Thanh Ward, Tan Phu District, 72009 Ho Chi Minh City, Viet Nam; Institute of Applied Research and Technology Transfer HUFI, Ho Chi Minh City University of Food Industry, 140 Le Trong Tan Street, Tay Thanh Ward, Tan Phu District, 72009 Ho Chi Minh City, Viet Nam.
| | - Binh-Nguyen Ong
- Faculty of Biotechnology, Nguyen-Tat-Thanh University, 298A-300A Nguyen-Tat-Thanh Street, District 04, Hochiminh City 72820, Viet Nam
| | - Vinh-Tuong Ngo
- Institute of Applied Research and Technology Transfer HUFI, Ho Chi Minh City University of Food Industry, 140 Le Trong Tan Street, Tay Thanh Ward, Tan Phu District, 72009 Ho Chi Minh City, Viet Nam
| | - Dai-Long Tran
- Van Lang University, Nguyen Khac Nhu Street, Co Giang Ward, Distric 01, Hochiminh City 72820, Viet Nam
| | - Thanh-Cong Nguyen
- Faculty of Biotechnology, Nguyen-Tat-Thanh University, 298A-300A Nguyen-Tat-Thanh Street, District 04, Hochiminh City 72820, Viet Nam
| | - Bich-Huy Tran-Thi
- Faculty of Biotechnology, Nguyen-Tat-Thanh University, 298A-300A Nguyen-Tat-Thanh Street, District 04, Hochiminh City 72820, Viet Nam
| | - Thanh-Tri Do
- Faculty of Biology, Ho Chi Minh City University of Education, 280 An Duong Vuong Street, District Ho Chi Minh City, Viet Nam
| | - Tran-Minh-Ly Nguyen
- Faculty of Business Administration, TU Bergakademie Freiberg, Akademiestraße 6, Freiberg 09599, Germany
| | - Xuan-Hoang Nguyen
- International Medical Consultants Ltd. Company, No 9, Lot A, Group 100, Hoang Cau, O Cho Dua Ward, Dong Da District, Hanoi 11511, Viet Nam
| | - Michael Melkonian
- Max Planck Institute for Plant Breeding Research, Department of Plant Microbe Interactions, Group Integrative Bioinformatics, Carl-von-Linné-Weg 10, 50829 Cologne, Germany
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Zhao G, Wang X, Hong Y, Liu X, Wang Q, Zhai Q, Zhang H. Attached cultivation of microalgae on rational carriers for swine wastewater treatment and biomass harvesting. BIORESOURCE TECHNOLOGY 2022; 351:127014. [PMID: 35307525 DOI: 10.1016/j.biortech.2022.127014] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 03/10/2022] [Accepted: 03/12/2022] [Indexed: 06/14/2023]
Abstract
Attachment effects of six carrier materials on the cultivation of high-value microalga Scenedesmus sp. LX1 in diluted swine wastewater were investigated. The results showed that when the initial algal densities were 5×105 cells/mL and 1×106 cells/mL in sterilized wastewater with 20-fold dilution, the biomass of microalgae attaching to geotextile was the highest. The contact angle and surface structure of the material affected the attachment of microalgae. Further, among the four dilutions, the highest attached biomass on geotextile was 414.47 mg/L in the sterilized wastewater at 20-fold, but the pollutants removal rate and attached biomass were higher in the non-sterile wastewater in the other three dilutions (original wastewater, 5-fold, 10-fold). Next, the microalgae were able to remove pollutants with the highest removal rates of COD, TN, NH4+-N and TP reaching to 86.92%, 60.75%, 71.81% and 96.13%. Moreover, the microalga was found to accumulate high-value products especially protein as high as 44.57%.
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Affiliation(s)
- Guangpu Zhao
- Beijing Key Laboratory for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Xiaoyan Wang
- Beijing Key Laboratory for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Yu Hong
- Beijing Key Laboratory for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
| | - Xiaoya Liu
- Beijing Key Laboratory for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Qiao Wang
- Beijing Key Laboratory for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Qingyu Zhai
- Beijing Key Laboratory for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Hongkai Zhang
- Beijing Key Laboratory for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
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Abstract
In view of high energy cost and water consumption in microalgae cultivation, microalgal-biofilm-based cultivation system has been advocated as a solution toward a more sustainable and resource friendlier system for microalgal biomass production. Algal-derived extracellular polymeric substances (EPS) form cohesive network to interconnect the cells and substrates; however, their interactions within the biofilm are poorly understood. This scenario impedes the biofilm process development toward resource recovery. Herein, this review elucidates on various biofilm cultivation modes and contribution of EPS toward biofilm adhesion. Immobilized microalgae can be envisioned by the colloid interactions in terms of a balance of both dispersive and polar interactions among three interfaces (cells, mediums and substrates). Last portion of this review is dedicated to the future perspectives and challenges on the EPS; with regard to the biopolymers extraction, biopolymers’ functional description and cross-referencing between model biofilms and full-scale biofilm systems are evaluated. This review will serve as an informative reference for readers having interest in microalgal biofilm phenomenon by incorporating the three main players in attached cultivation systems: microalgae, EPS and supporting materials. The ability to mass produce these miniature cellular biochemical factories via immobilized biofilm technology will lay the groundwork for a more sustainable and feasible production.
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Affiliation(s)
- Yi Tong Cheah
- School of Chemical Engineering, Engineering Campus, University of Science Malaysia, Nibong Tebal, Penang, Malaysia
| | - Derek Juinn Chieh Chan
- School of Chemical Engineering, Engineering Campus, University of Science Malaysia, Nibong Tebal, Penang, Malaysia
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4
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Immobilising Microalgae and Cyanobacteria as Biocomposites: New Opportunities to Intensify Algae Biotechnology and Bioprocessing. ENERGIES 2021. [DOI: 10.3390/en14092566] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
There is a groundswell of interest in applying phototrophic microorganisms, specifically microalgae and cyanobacteria, for biotechnology and ecosystem service applications. However, there are inherent challenges associated with conventional routes to their deployment (using ponds, raceways and photobioreactors) which are synonymous with suspension cultivation techniques. Cultivation as biofilms partly ameliorates these issues; however, based on the principles of process intensification, by taking a step beyond biofilms and exploiting nature inspired artificial cell immobilisation, new opportunities become available, particularly for applications requiring extensive deployment periods (e.g., carbon capture and wastewater bioremediation). We explore the rationale for, and approaches to immobilised cultivation, in particular the application of latex-based polymer immobilisation as living biocomposites. We discuss how biocomposites can be optimised at the design stage based on mass transfer limitations. Finally, we predict that biocomposites will have a defining role in realising the deployment of metabolically engineered organisms for real world applications that may tip the balance of risk towards their environmental deployment.
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Chu FJ, Wan TJ, Pai TY, Lin HW, Liu SH, Huang CF. Use of magnetic fields and nitrate concentration to optimize the growth and lipid yield of Nannochloropsis oculata. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2020; 253:109680. [PMID: 31634748 DOI: 10.1016/j.jenvman.2019.109680] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 09/28/2019] [Accepted: 10/05/2019] [Indexed: 06/10/2023]
Abstract
Microalgae produce increased lipid content accompanied by a significant decrease in cell density with decreasing nitrate concentration. Magnetic fields (MF) have been reported as a factor that could accelerate metabolism and growth in microalgae culture. Thus, this study aimed to optimize the influence of MF and nitrate concentration (sodium nitrate, N) on the growth and lipid productivity of Nannochloropsis oculata. A single-factor experiment integrated with response surface methodology (RSM) via central composite design (CCD) was performed. The results showed that the maximum specific growth rate (0.24 d-1) and maximum lipid productivity (38 mg L-1 d-1) obtained in this study were higher than those of the control culture (by 166% and 103%, respectively). This study also found that the two-way interaction term MF × N had a significant effect on cell growth but not on lipid production. It was concluded that to design appropriate MF for enhanced lipid productivity due to cell growth, further research must focus on developing an understanding of the relationship between the bioeffects of the magnetic field and the proteomic changes involved in lipid accumulation strategies. This approach would enable the design of conditions to obtain inexpensive high-value products from N. oculata.
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Affiliation(s)
- Feng-Jen Chu
- Graduate School of Engineering Science and Technology, National Yunlin University of Science and Technology, Douliou, 64002, Yunlin, Taiwan
| | - Terng-Jou Wan
- Department of Safety, Health and Environment Engineering, National Yunlin University of Science and Technology, Douliou, 64002, Yunlin, Taiwan.
| | - Tzu-Yi Pai
- Master Program of Environmental Education and Management, Department of Science Education and Application, National Taichung University of Education, Taichung, 40306, Taiwan
| | - Hsiao-Wen Lin
- Department of Safety, Health and Environment Engineering, National Yunlin University of Science and Technology, Douliou, 64002, Yunlin, Taiwan
| | - Shang-Hao Liu
- Department of Chemical Engineering, Anhui University of Science and Technology, Huainan, 232001, Anhui, China
| | - Chung-Fu Huang
- School of Environmental and Chemical Engineering, Zhaoqing University, Zhaoqing, 526061, Guangdong, China
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Mantzorou A, Ververidis F. Microalgal biofilms: A further step over current microalgal cultivation techniques. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 651:3187-3201. [PMID: 30463168 DOI: 10.1016/j.scitotenv.2018.09.355] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 09/24/2018] [Accepted: 09/28/2018] [Indexed: 05/15/2023]
Abstract
The scientific community has turned its interest to microalgae lately, because of their countless applications such as wastewater treatment and pharmaceutical industry. Nevertheless, so far applied cultivation methods are still prohibitive. Ordinary cultivation techniques in which microalgae are suspended in liquid medium suffer from many bottlenecks, such as low biomass productivities, difficulty in biomass harvesting and recovery, high installation and operating cost, high water requirements etc. Although, microalgal biofilms are known to be a nuisance because of surfaces fouling, they have emerged as an innovative technology with which microalgae are developed attached to a solid surface. This technique seems to be advantageous as compared to conventional cultivation systems. Microalgal biofilm systems could resolve the problematic aspects of ordinary cultivation techniques such as low biomass productivities, water management and biomass recovery. A detailed description of this technique with respect to the parameters affecting them is reviewed in this work.
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Affiliation(s)
- Antonia Mantzorou
- Plant Biochemistry and Biotechnology Group, Biological and Biotechnological Applications Laboratory, Department of Agriculture, School of Agriculture, Food and Nutrition, Technological Educational Institute of Crete, Heraklion, Greece
| | - Filippos Ververidis
- Plant Biochemistry and Biotechnology Group, Biological and Biotechnological Applications Laboratory, Department of Agriculture, School of Agriculture, Food and Nutrition, Technological Educational Institute of Crete, Heraklion, Greece.
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7
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Attached culture of Chlamydomonas sp. JSC4 for biofilm production and TN/TP/Cu(II) removal. Biochem Eng J 2019. [DOI: 10.1016/j.bej.2018.09.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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8
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Enhanced CO2 biofixation and protein production by microalgae biofilm attached on modified surface of nickel foam. Bioprocess Biosyst Eng 2018; 42:521-528. [DOI: 10.1007/s00449-018-2055-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 11/21/2018] [Indexed: 12/11/2022]
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9
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Enhancing lipid production in attached culture of a thermotolerant microalga Desmodesmus sp. F51 using light-related strategies. Biochem Eng J 2018. [DOI: 10.1016/j.bej.2017.09.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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Xu XQ, Wang JH, Zhang TY, Dao GH, Wu GX, Hu HY. Attached microalgae cultivation and nutrients removal in a novel capillary-driven photo-biofilm reactor. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.08.028] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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11
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Huang Y, Xiong W, Liao Q, Fu Q, Xia A, Zhu X, Sun Y. Comparison of Chlorella vulgaris biomass productivity cultivated in biofilm and suspension from the aspect of light transmission and microalgae affinity to carbon dioxide. BIORESOURCE TECHNOLOGY 2016; 222:367-373. [PMID: 27741475 DOI: 10.1016/j.biortech.2016.09.099] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 09/23/2016] [Accepted: 09/24/2016] [Indexed: 06/06/2023]
Abstract
To investigate light transmission and cells affinity to CO2, Chlorellavulgaris was attached to microfiltration membrane that laid on the solidified BG11 medium compared to that in suspended cultivation mode in this study. The results showed that C. vulgaris showed a 30.4% higher biomass production (103gm-2) in attached than in suspend system. The upper layer of biofilm with a thickness of 41.31μm (the corresponding areal density of 40gm-2) was effectively illuminated under light intensity of 120μmolm-2s-1 and more than 40% of the microalgal cells were in light even the areal density was high to 100gm-2. While only 2.5% of the cells were effectively illuminated in the suspended cultivation system. Furthermore, microalgae cells in biofilm showed a higher affinity to CO2 compared with that in suspension, and CO2 saturation point of microalgae cells in biofilm was 1.5% but 4.5% in suspension.
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Affiliation(s)
- Yun Huang
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400044, China; Institute of Engineering Thermophysics, Chongqing University, Chongqing 400044, China
| | - Wei Xiong
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400044, China; Institute of Engineering Thermophysics, Chongqing University, Chongqing 400044, China
| | - Qiang Liao
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400044, China; Institute of Engineering Thermophysics, Chongqing University, Chongqing 400044, China.
| | - Qian Fu
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400044, China; Institute of Engineering Thermophysics, Chongqing University, Chongqing 400044, China
| | - Ao Xia
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400044, China; Institute of Engineering Thermophysics, Chongqing University, Chongqing 400044, China
| | - Xun Zhu
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400044, China; Institute of Engineering Thermophysics, Chongqing University, Chongqing 400044, China
| | - Yahui Sun
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400044, China; Institute of Engineering Thermophysics, Chongqing University, Chongqing 400044, China
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12
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Shin WS, Lee H, Sung MG, Hwang KT, Jung SM, Kwon JH. Enrichment as a screening method for a high-growth-rate microalgal strain under continuous cultivation system. BIOTECHNOL BIOPROC E 2016. [DOI: 10.1007/s12257-015-0716-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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13
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Shen Y, Zhu W, Chen C, Nie Y, Lin X. Biofilm formation in attached microalgal reactors. Bioprocess Biosyst Eng 2016; 39:1281-8. [DOI: 10.1007/s00449-016-1606-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 04/05/2016] [Indexed: 11/29/2022]
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14
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Shen Y, Zhu W, Chen C, Nie Y. Glycine induced culture-harvesting strategy for Botryococcus braunii. J Biosci Bioeng 2016; 121:424-30. [DOI: 10.1016/j.jbiosc.2015.08.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 06/25/2015] [Accepted: 08/06/2015] [Indexed: 10/22/2022]
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Zhang L, Chen L, Wang J, Chen Y, Gao X, Zhang Z, Liu T. Attached cultivation for improving the biomass productivity of Spirulina platensis. BIORESOURCE TECHNOLOGY 2015; 181:136-42. [PMID: 25647023 DOI: 10.1016/j.biortech.2015.01.025] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 01/06/2015] [Accepted: 01/08/2015] [Indexed: 05/26/2023]
Abstract
To improve cultivation efficiency for microalgae Spirulina platensis is related to increase its potential use as food source and as an effective alternative for CO2 fixation. The present work attempted to establish a technique, namely attached cultivation, for S. platensis. Laboratory experiments were made firstly to investigate optimal conditions on attached cultivation. The optimal conditions were found: 25 g m(-2) for initial inoculum density using electrostatic flocking cloth as substrata, light intensity lower than 200 μmol m(-2) s(-1), CO2 enriched air flow (0.5%) at a superficial aeration rate of 0.0056 m s(-1) in a NaHCO3-free Zarrouk medium. An outdoor attached cultivation bench-scale bioreactor was built and a 10d culture of S. platensis was carried out with daily harvesting. A high footprint areal biomass productivity of 60 g m(-2) d(-1) was obtained. The nutrition of S. platensis with attached cultivation is identical to that with conventional liquid cultivation.
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Affiliation(s)
- Lanlan Zhang
- College of Food Science and Engineering, Ocean University of China, Qingdao, Shandong 266101, PR China; Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, PR China
| | - Lin Chen
- Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, PR China
| | - Junfeng Wang
- Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, PR China
| | - Yu Chen
- Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, PR China
| | - Xin Gao
- College of Food Science and Engineering, Ocean University of China, Qingdao, Shandong 266101, PR China
| | - Zhaohui Zhang
- College of Food Science and Engineering, Ocean University of China, Qingdao, Shandong 266101, PR China.
| | - Tianzhong Liu
- Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, PR China.
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An auto-flocculation strategy for Chlorella vulgaris. Biotechnol Lett 2014; 37:75-80. [PMID: 25208747 DOI: 10.1007/s10529-014-1655-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 08/27/2014] [Indexed: 10/24/2022]
Abstract
Extracellular polymeric substances (EPS) excreted by microalgae are effective for microalgal flocculation. An auto-flocculation strategy was conducted by adding adequate glycine into the medium, stimulating EPS secretion to achieve auto-flocculation, and recycling the supernatant medium for further cultivation. Bound EPS positively corresponded with the solid concentration achieved. Increasing the mixing time enhanced the secretion of bound EPS but the influence of glycine was affected by light intensity. Increasing the glycine dose decreased the production of bound EPS with light intensity of 250 μmol m(-2) s(-1), but increased the production of bound EPS with light intensity of 125 μmol m(-2) s(-1). Maximum solid concentration of 21.2 g l(-1) with biomass recovery rate of 71 % was achieved under light intensity of 250 μmol m(-2) s(-1), mixing time of 3 days and glycine at 0.1 g l(-1).
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