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Bentahar J, Deschênes JS. A reliable multi-nutrient model for the rapid production of high-density microalgal biomass over a broad spectrum of mixotrophic conditions. Bioresour Technol 2023; 381:129162. [PMID: 37178778 DOI: 10.1016/j.biortech.2023.129162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/04/2023] [Accepted: 05/08/2023] [Indexed: 05/15/2023]
Abstract
The superior microalgal biomass productivities obtained under mixotrophic conditions have been widely demonstrated. However, to attain the full potential of the method, optimal conditions for biomass production and resource utilization need to be determined and successfully exploited throughout the process operation. Detailed kinetic mathematical models have often proved most efficient tools for predicting process behavior and governing its overall operation. This paper presents an extensive study for obtaining a highly reliable model for mixotrophic production of microalgae covering a wide set and range of nutritional conditions (10-fold the concentration range of Bold's Basal Medium) and biomass yields up to 6.68 g.L-1 after only 6 days. The final reduced model includes a total of five state variables and nine parameters: model calibration resulted in very small 95% confidence intervals and relative errors below 5% for all parameters. Model validation showed high reliability with R2 correlation values between 0.77 and 0.99.
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Affiliation(s)
- Jihed Bentahar
- Département de mathématiques, d'informatique et de génie, Collectif de recherche appliquée aux bioprocédés et à la chimie de l'environnement (CRABE), Université du Québec à Rimouski, 300, Allée des Ursulines, Rimouski, Québec G5L 3A1, Canada; Département des sciences des aliments, Institut sur la Nutrition et les Aliments Fonctionnels (INAF), Faculté des sciences de l'agriculture et de l'alimentation, Université Laval, 2425, rue de l'Agriculture, Québec, Québec G1V 0A6, Canada.
| | - Jean-Sébastien Deschênes
- Département de mathématiques, d'informatique et de génie, Collectif de recherche appliquée aux bioprocédés et à la chimie de l'environnement (CRABE), Université du Québec à Rimouski, 300, Allée des Ursulines, Rimouski, Québec G5L 3A1, Canada; Département des sciences des aliments, Institut sur la Nutrition et les Aliments Fonctionnels (INAF), Faculté des sciences de l'agriculture et de l'alimentation, Université Laval, 2425, rue de l'Agriculture, Québec, Québec G1V 0A6, Canada
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Bosman CE, van Wyk P, Pott RWM, Bradshaw SM. The effect of diurnal light cycles on biohydrogen production in a thermosiphon photobioreactor. AMB Express 2023; 13:26. [PMID: 36867285 PMCID: PMC9984629 DOI: 10.1186/s13568-023-01534-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 02/24/2023] [Indexed: 03/04/2023] Open
Abstract
Hydrogen production via microbial photofermentation shows great promise as a method for sustainable hydrogen production; however, operating costs associated with photofermentative hydrogen production need to be reduced. Costs can be reduced using a passive circulation system like the thermosiphon photobioreactor, and by operating it under natural sunlight. In this study, an automated system was implemented to investigate the effect of diurnal light cycles on the hydrogen productivity and growth of Rhodopseudomonas palustris and on the operation of a thermosiphon photobioreactor, under controlled conditions. Diurnal light cycles, simulating daylight times, were found to reduce hydrogen production in the thermosiphon photobioreactor demonstrating a low maximum production rate of 0.015 mol m-3 h-1 (± 0.002 mol m-3 h-1) as compared to 0.180 mol m-3 h-1 (± 0.0003 mol m-3 h-1) under continuous illumination. Glycerol consumption as well as hydrogen yield also decreased under diurnal light cycles. Nonetheless, hydrogen production in a thermosiphon photobioreactor under outdoor conditions was demonstrated as possible avenue for further investigation.
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Affiliation(s)
- Catharine Elizabeth Bosman
- grid.11956.3a0000 0001 2214 904XDepartment of Process Engineering, Stellenbosch University, Banghoek Road, Stellenbosch, 7600 South Africa ,grid.11956.3a0000 0001 2214 904XDepartment of Process Engineering, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch, 7602 South Africa
| | - Petrie van Wyk
- grid.11956.3a0000 0001 2214 904XDepartment of Process Engineering, Stellenbosch University, Banghoek Road, Stellenbosch, 7600 South Africa ,grid.11956.3a0000 0001 2214 904XDepartment of Process Engineering, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch, 7602 South Africa
| | - Robert William McClelland Pott
- Department of Process Engineering, Stellenbosch University, Banghoek Road, Stellenbosch, 7600, South Africa. .,Department of Process Engineering, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch, 7602, South Africa.
| | - Steven Martin Bradshaw
- grid.11956.3a0000 0001 2214 904XDepartment of Process Engineering, Stellenbosch University, Banghoek Road, Stellenbosch, 7600 South Africa ,grid.11956.3a0000 0001 2214 904XDepartment of Process Engineering, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch, 7602 South Africa
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Struk M, Sepúlveda-Muñoz CA, Kushkevych I, Muñoz R. Photoautotrophic removal of hydrogen sulfide from biogas using purple and green sulfur bacteria. J Hazard Mater 2023; 443:130337. [PMID: 36370482 DOI: 10.1016/j.jhazmat.2022.130337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 10/31/2022] [Accepted: 11/04/2022] [Indexed: 06/16/2023]
Abstract
Biogas desulfurization based on anoxygenic photosynthetic processes represents an alternative to physicochemical technologies, decreasing the risk of O2 and N2 contamination. This work aimed at assessing the potential of Allochromatium vinosum and Chlorobium limicola for biogas desulfurization under different light intensities (10 and 25 klx) and H2S concentrations (1 %, 1.5 % and 2 %) in batch photobioreactors. In addition, the influence of rising biogas flow rates (2.9, 5.8 and 11.5 L d-1 in stage I, II and III, respectively) on the desulfurization performance in a 2.3 L photobioreactor utilizing C. limicola under continuous mode was assessed. The light intensity of 25 klx negatively influenced the growth of A. vinosum and C. limicola, resulting in decreased H2S removal capacity. An increase in H2S concentrations resulted in higher volumetric H2S removal rates in C. limicola (2.9-5.3 mg L-1 d-1) tests compared to A. vinosum (2.4-4.6 mg L-1 d-1) tests. The continuous photobioreactor completely removed H2S from biogas in stage I and II. The highest flow rate in stage III induced a deterioration in the desulfurization activity of C. limicola. Overall, the high H2S tolerance of A. vinosum and C. limicola supports their use in H2S desulfurization from biogas.
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Affiliation(s)
- Martin Struk
- Department of Experimental Biology, Faculty of Science, Masaryk University in Brno, Kamenice 735/5, 625 00 Brno, Czech Republic; Institute of Sustainable Processes, Dr. Mergelina s/n, 47011 Valladolid, Spain; Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid, Spain
| | - Cristian A Sepúlveda-Muñoz
- Institute of Sustainable Processes, Dr. Mergelina s/n, 47011 Valladolid, Spain; Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid, Spain
| | - Ivan Kushkevych
- Department of Experimental Biology, Faculty of Science, Masaryk University in Brno, Kamenice 735/5, 625 00 Brno, Czech Republic
| | - Raúl Muñoz
- Institute of Sustainable Processes, Dr. Mergelina s/n, 47011 Valladolid, Spain; Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid, Spain.
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Liu Q, Chang F, Xie P, Zhang Y, Duan L, Li H, Zhang X, Zhang Y, Li D, Zhang H. Microbiota assembly patterns and diversity of nine plateau lakes in Yunnan, southwestern China. Chemosphere 2023; 314:137700. [PMID: 36587916 DOI: 10.1016/j.chemosphere.2022.137700] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 12/23/2022] [Accepted: 12/28/2022] [Indexed: 06/17/2023]
Abstract
Microbes serve as important components of ecosystem services and biogeochemical processes in plateau lakes. However, the features of microbiota assembly, abundance and diversity in plateau lakes remain unclear. The microbial communities in surface water from nine plateau lakes in Yunnan Plateau, southwestern China, in the dry and rainy seasons were explored using 16S rRNA gene and 18S rRNA gene sequencing. The results showed that the bacterial community compositions were homogeneous while those of micro-eukaryotes were heterogeneous in plateau lakes. In both seasons, the bacterial phyla of Proteobacteria and Actinobacteriota predominated in oligotrophic lakes. The mesotrophic lakes were dominated by Proteobacteria, Actinobacteriota, Bacteroidota and Cyanobacteria. The eutrophic lakes were mainly dominated by Proteobacteria, Actinobacteriota and Cyanobacteria. The phylum SAR_k_norank had the major micro-eukaryotes in these plateau lakes. The alpha-diversity of bacteria declined in the rainy season, while that of micro-eukaryotes varied from lake to lake. The drivers of microbiotic community assembly in the dry season were identified as nutrient level-related factors. In the rainy season, however, the microbiota in oligotrophic lakes were related to nutrient levels. Microbial communities were driven by precipitation in mesotrophic and eutrophic lakes with large water volumes, while those in lakes with small water volumes were regulated by nutrient level-related factors. Our findings pose first and unique insights into the microbiota of the nine plateau lakes in Yunnan Plateau, providing important ecological knowledge for these lakes with different characteristics.
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Affiliation(s)
- Qi Liu
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan, 650500, China
| | - Fengqin Chang
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan, 650500, China
| | - Ping Xie
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan, 650500, China; Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, CAS, Wuhan, 430072, China
| | - Yang Zhang
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan, 650500, China
| | - Lizeng Duan
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan, 650500, China
| | - Haoyu Li
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan, 650500, China
| | - Xiaonan Zhang
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan, 650500, China
| | - Yun Zhang
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan, 650500, China
| | - Donglin Li
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan, 650500, China
| | - Hucai Zhang
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan, 650500, China.
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Bosman CE, Pott RWM, Bradshaw SM. Modelling and testing of a light reflector system for the enhancement of biohydrogen production in a thermosiphon photobioreactor. J Biotechnol 2023; 361:57-65. [PMID: 36462618 DOI: 10.1016/j.jbiotec.2022.11.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 09/21/2022] [Accepted: 11/28/2022] [Indexed: 12/02/2022]
Abstract
One of the main factors affecting hydrogen production and growth of photofermentative microorganisms is light; low light penetration and utilization are significant bottlenecks in photofermentative hydrogen production systems. In this study, light distribution in a thermosiphon photobioreactor operated with Rhodopseudomonas palustris was investigated. Radiation fields were modelled and simulated using computational fluid dynamics (ANSYS® Fluent, 2019 R2) and a reflector system was evaluated for the enhancement of light distribution in a thermosiphon photobioreactor. The effect of the reflector system was investigated experimentally in terms of hydrogen production, carbon substrate consumption and biomass circulation in the reactor. With the addition of the reflector system, hydrogen production was increased by 48% while glycerol consumption was increased from approximately 24% to 32%. After 336 h, the concentration of R. palustris cells still in suspension ranged from 0.13 to 0.18 g∙L-1, with no discernible difference in concentration between the systems with and without reflectors. Collectively, the reflector system was shown to be a viable option in enhancing light distribution in photobioreactors, with an associated increase in both hydrogen production as well as glycerol consumption.
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Affiliation(s)
- Catharine Elizabeth Bosman
- Department of Process Engineering, Stellenbosch University, Banghoek Road, Stellenbosch 7600, South Africa.
| | | | - Steven Martin Bradshaw
- Department of Process Engineering, Stellenbosch University, Banghoek Road, Stellenbosch 7600, South Africa.
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Bosman CE, McClelland Pott RW, Bradshaw SM. A Thermosiphon Photobioreactor for Photofermentative Hydrogen Production by Rhodopseudomonas palustris. Bioengineering (Basel) 2022; 9:344. [PMID: 35892758 DOI: 10.3390/bioengineering9080344] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/22/2022] [Accepted: 07/22/2022] [Indexed: 11/20/2022]
Abstract
A thermosiphon photobioreactor (TPBR) can potentially be used for biohydrogen production, circumventing the requirement for external mixing energy inputs. In this study, a TPBR is evaluated for photofermentative hydrogen production by Rhodopseudomonas palustris (R. palustris). Experiments were conducted in a TPBR, and response surface methodology (RSM), varying biomass concentration, and light intensity and temperature were employed to determine the operating conditions for the enhancement of both hydrogen production as well as biomass suspension. Biomass concentration was found to have had the most pronounced effect on both hydrogen production as well as biomass suspension. RSM models predicted maximum specific hydrogen production rates of 0.17 mol m−3h−1 and 0.21 mmol gCDW−1h−1 at R. palustris concentrations of 1.21 and 0.4 g L−1, respectively. The experimentally measured hydrogen yield was in the range of 45 to 77% (±3.8%), and the glycerol consumption was 8 to 19% (±0.48). At a biomass concentration of 0.40 g L−1, the highest percentage of biomass (72.3%), was predicted to remain in suspension in the TPBR. Collectively, the proposed novel photobioreactor was shown to produce hydrogen as well as passively circulate biomass.
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