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Yadav PK, Kumar A, Pandey P, Kumar D, Singh A. Modulations of functional traits of Spinacia oleracea plants exposed to cadmium stress by using H 2S as an antidote: a regulatory mechanism. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2023; 29:2021-2033. [PMID: 38222276 PMCID: PMC10784438 DOI: 10.1007/s12298-023-01389-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 11/06/2023] [Accepted: 11/10/2023] [Indexed: 01/16/2024]
Abstract
The present study is based on the application of H2S as an exogenous antidote in Spinacia oleracea (spinach) plants grown in Cd-contaminated (50 ppm) soil. The different doses of H2S in the form of NaHS (10, 50, 100, 200, and 500 μM) have been applied as a foliar spray to regulate the physiological attributes under Cd toxicity. Over to control, the plants grown in Cd alone showed a reduction in the fresh biomass by 48% with more production of oxidative biomarkers (H2O2, SOR, and MDA content) and antioxidative enzymes (SOD, POD, APX, and GR). Further, with the exogenous application of H2S, among all the doses the fresh biomass was found to be maximally increased at 100 μM dose by 76%, and the Cd content was reduced significantly by 25% in the shoot compared to plants grown in Cd treated soil alone. With the decrease in Cd content in the shoot, the production of H2O2, SOR, and MDA content was reduced by 52%, 40%, and 38% respectively, at 100 μM compared to the plants grown in Cd-treated soil. The activities of estimated antioxidative enzymes showed a reduction in their activities up to 100 μM. Whereas, Glutathione reductase (GR) and Phytochelatins (PCs) showed different trends with their higher values in plants treated with NaHS in the presence of Cd. At 100 μM the GR and PCs, respectively showed 48% and 37% increment over Cd-treated plants alone. At this dose, the relative expression of SOD, POD, APX, GR, and PCS5 (Phytochelatin synthetase enzyme) genes, and other functional activities (SEM and fluorescence kinetics) supported the best performance of plants at 100 μM. Therefore, among all the doses, 100 μM dose of H2S has significantly reduced the Cd toxicity by maintaining the growth and other functional traits of plants. The correlation analysis also supported the result by showing a relationship between H2S application and Cd uptake. So, with this strategy, the plants grown in metal-contaminated fields can be improved qualitatively as well as quantitatively. With further experimentation, the mode of application could be explored to increase its efficiency and to promote this strategy at a wider scale. Supplementary Information The online version contains supplementary material available at 10.1007/s12298-023-01389-3.
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Affiliation(s)
- Pradeep Kumar Yadav
- Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, UP 221005 India
| | - Arun Kumar
- Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, UP 221005 India
| | - Prashasti Pandey
- Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, UP 221005 India
| | - Deepak Kumar
- Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, UP 221005 India
| | - Anita Singh
- Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, UP 221005 India
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Singh RP, Yadav P, Kumar A, Hashem A, Avila-Quezada GD, Abd_Allah EF, Gupta RK. Salinity-Induced Physiochemical Alterations to Enhance Lipid Content in Oleaginous Microalgae Scenedesmus sp. BHU1 via Two-Stage Cultivation for Biodiesel Feedstock. Microorganisms 2023; 11:2064. [PMID: 37630624 PMCID: PMC10459255 DOI: 10.3390/microorganisms11082064] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 08/05/2023] [Accepted: 08/08/2023] [Indexed: 08/27/2023] Open
Abstract
In the recent past, various microalgae have been considered a renewable energy source for biofuel production, and their amount and extent can be enhanced by applying certain types of stress including salinity. Although microalgae growing under salinity stress result in a higher lipid content, they simultaneously reduce in growth and biomass output. To resolve this issue, the physiochemical changes in microalgae Scenedesmus sp. BHU1 have been assessed through two-stage cultivation. In stage-I, the maximum carbohydrate and lipid contents (39.55 and 34.10%) were found at a 0.4 M NaCl concentration, while in stage-II, the maximum carbohydrate and lipid contents (42.16 and 38.10%) were obtained in the 8-day-old culture. However, under increased salinity, Scenedesmus sp. BHU1 exhibited a decrease in photosynthetic attributes, including Chl-a, Chl-b, Fv/Fm, Y(II), Y(NPQ), NPQ, qP, qL, qN, and ETRmax but increased Y(NO) and carotenoids content. Apart from physiological attributes, osmoprotectants, stress biomarkers, and nonenzymatic antioxidants were also studied to elucidate the role of reactive oxygen species (ROS) facilitated lipid synthesis. Furthermore, elemental and mineral ion analysis of microalgal biomass was performed to evaluate the biomass quality for biofuel and cell homeostasis. Based on fluorometry analysis, we found the maximum neutral lipids in the 8-day-old grown culture at stage-II in Scenedesmus sp. BHU1. Furthermore, the use of Fourier-transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy analyses confirmed the presence of higher levels of hydrocarbons and triacylglycerides (TAGs) composed of saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs) in the 8-day-old culture. Therefore, Scenedesmus sp. BHU1 can be a promising microalga for potential biodiesel feedstock.
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Affiliation(s)
- Rahul Prasad Singh
- Laboratory of Algal Research, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India; (R.P.S.); (P.Y.)
| | - Priya Yadav
- Laboratory of Algal Research, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India; (R.P.S.); (P.Y.)
| | - Ajay Kumar
- Amity Institute of Biotechnology, Amity University, Noida 201303, India
| | - Abeer Hashem
- Botany and Microbiology Department, College of Science, King Saud University, P.O. Box. 2460, Riyadh 11451, Saudi Arabia;
| | | | - Elsayed Fathi Abd_Allah
- Plant Production Department, College of Food and Agricultural Sciences, King Saud University, P.O. Box. 2460, Riyadh 11451, Saudi Arabia;
| | - Rajan Kumar Gupta
- Laboratory of Algal Research, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India; (R.P.S.); (P.Y.)
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Ren HY, Song X, Kong F, Song Q, Ren NQ, Liu BF. Lipid production characteristics of a newly isolated microalga Asterarcys quadricellulare R-56 as biodiesel feedstock. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:48339-48350. [PMID: 36757593 DOI: 10.1007/s11356-023-25728-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 01/31/2023] [Indexed: 02/10/2023]
Abstract
In this study, a new microalgal strain, Asterarcys quadricellulare R-56, was isolated for biomass and lipid production. The effects of carbon and nitrogen sources and initial pH on the cell growth and lipid accumulation of strain R-56 were investigated. At 10 g L-1 glucose, 0.6 g L-1 sodium nitrate, and pH 7, the highest biomass of 4.18 g L-1 and lipid content of 43.66% were obtained. Microalgae had a broad pH tolerance in the range of 5-11, and the pH of the culture medium was close to neutral at the end of cultivation. The maximum contents of chlorophyll, carbohydrate, and protein under the recommended culture conditions were 19.47 mg mL-1, 21.80%, and 29.94%, respectively. Palmitic and palmitoleic acid contents in strain R-56 accounted for as high as 83.73% of total fatty acids. This study suggested that strain R-56 was a promising lipid producer for high-quality biodiesel production.
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Affiliation(s)
- Hong-Yu Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, 73 Huanghe Road, Harbin, 150090, China
| | - Xueting Song
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, 73 Huanghe Road, Harbin, 150090, China
| | - Fanying Kong
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, 73 Huanghe Road, Harbin, 150090, China. .,School of Water Conservancy and Civil Engineering, Northeast Agricultural University, Harbin, 150030, China.
| | - Qingqing Song
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, 73 Huanghe Road, Harbin, 150090, China
| | - Nan-Qi Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, 73 Huanghe Road, Harbin, 150090, China
| | - Bing-Feng Liu
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, 73 Huanghe Road, Harbin, 150090, China
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Magwell PFR, Djoudjeu KT, Minyaka E, Tavea MF, Fotsop OW, Tagnikeu RF, Fofou AM, Darelle CKV, Dzoyem CUD, Lehman LG. Sodium Bicarbonate (NaHCO 3) Increases Growth, Protein and Photosynthetic Pigments Production and Alters Carbohydrate Production of Spirulina platensis. Curr Microbiol 2023; 80:63. [PMID: 36595115 DOI: 10.1007/s00284-022-03165-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 12/23/2022] [Indexed: 01/04/2023]
Abstract
Improving the biochemical status of Spirulina platensis will enhance the functional properties of this microalgae. The present study investigated the effects of adding NaHCO3 to the culture medium on the growth rate and biochemical composition, particularly the coproduction of proteins, carbohydrates, and photosynthetic pigments of S. platensis. Spirulina platensis was grown in different NaHCO3 concentrations (0-16 g L-1). NaHCO3 positively affected the biomass production. The growth of S. platensis and biochemical compound content increased with an increase in the NaHCO3 concentration. The microalgae biomass grown on NaHCO3 also contained higher amounts of protein (64.20 ± 4.18% w w-1) and photosynthetic pigments (phycocyanin and chlorophyll a, b, and total). Protein productivity was especially enhanced by approximately 6-25% (from 0.006 ± 0.0030 to 0.025 ± 0.0031 mg L-1 day-1) with the addition of NaHCO3 compared to the control. In contrast, the content of carbohydrates and antioxidant compounds (phenolic, polyphenol oxidase, and peroxidase activities) decreased with culture age and an increase in the NaHCO3 concentration. These results suggest that S. platensis uses NaHCO3 as a carbon source for photosynthesis, biomass production, and acts as a metabolic energy carrier toward the synthesis of proteins and photosynthetic pigments, which are more energy-consuming metabolites than carbohydrates. The addition of NaHCO3 to the culture media is a potentially useful strategy toward improving the protein and photosynthetic pigment productivity of S. platensis.
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Affiliation(s)
- Pierre Fils Rodrigue Magwell
- Biochemistry Laboratory, Faculty of Science, University of Douala, P.O. Box 24157, Douala, Cameroon.,Institute of Agricultural Research for Development, Nko'olong Station, Kribi, Cameroon
| | - Kennedy Tchoffo Djoudjeu
- Biochemistry Laboratory, Faculty of Science, University of Douala, P.O. Box 24157, Douala, Cameroon
| | - Emile Minyaka
- Biochemistry Laboratory, Faculty of Science, University of Douala, P.O. Box 24157, Douala, Cameroon.
| | - Marie-Frédéric Tavea
- Biochemistry Laboratory, Faculty of Science, University of Douala, P.O. Box 24157, Douala, Cameroon
| | - Oscar Wamba Fotsop
- Laboratory of Plant Biology, Faculty of Science, University of Douala, Douala, Cameroon
| | - Romeo Fobasso Tagnikeu
- Biochemistry Laboratory, Faculty of Science, University of Douala, P.O. Box 24157, Douala, Cameroon
| | - Apollin Medueghue Fofou
- Biochemistry Laboratory, Faculty of Science, University of Douala, P.O. Box 24157, Douala, Cameroon
| | | | - Camille Ulrich Dzokouo Dzoyem
- CARBAP-African Center for Research on Bananas and Plantains, Njombe, Cameroon.,Institute of Agricultural Research for Development, Multipurpose Station of Njombe, Yaoundé, Cameroon
| | - Léopold Gustave Lehman
- Laboratory of Animal Biology and Physiology, Faculty of Science, University of Douala, Douala, Cameroon
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Oxygen stress mitigation for microalgal biomass productivity improvement in outdoor raceway ponds. ALGAL RES 2022. [DOI: 10.1016/j.algal.2022.102901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Fungal Contamination in Microalgal Cultivation: Biological and Biotechnological Aspects of Fungi-Microalgae Interaction. J Fungi (Basel) 2022; 8:jof8101099. [PMID: 36294664 PMCID: PMC9605242 DOI: 10.3390/jof8101099] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 10/12/2022] [Accepted: 10/15/2022] [Indexed: 11/17/2022] Open
Abstract
In the last few decades, the increasing interest in microalgae as sources of new biomolecules and environmental remediators stimulated scientists’ investigations and industrial applications. Nowadays, microalgae are exploited in different fields such as cosmeceuticals, nutraceuticals and as human and animal food supplements. Microalgae can be grown using various cultivation systems depending on their final application. One of the main problems in microalgae cultivations is the possible presence of biological contaminants. Fungi, among the main contaminants in microalgal cultures, are able to influence the production and quality of biomass significantly. Here, we describe fungal contamination considering both shortcomings and benefits of fungi-microalgae interactions, highlighting the biological aspects of this interaction and the possible biotechnological applications.
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Singh RP, Yadav P, Kumar A, Hashem A, Al-Arjani ABF, Abd Allah EF, Rodríguez Dorantes A, Gupta RK. Physiological and Biochemical Responses of Bicarbonate Supplementation on Biomass and Lipid Content of Green Algae Scenedesmus sp. BHU1 Isolated From Wastewater for Renewable Biofuel Feedstock. Front Microbiol 2022; 13:839800. [PMID: 35444634 PMCID: PMC9015788 DOI: 10.3389/fmicb.2022.839800] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 02/15/2022] [Indexed: 11/15/2022] Open
Abstract
In the present study, different microalgae were isolated from wastewater environment and evaluated for higher growth and lipid accumulation. The growth adaptability of all the isolated microalgae were tested for carbon source with supplementation of sodium bicarbonate in BG-11 N+ medium. Further based on the uptake rate of sodium bicarbonate and growth behavior, microalgal strains were selected for biofuel feedstock. During the study, growth parameters of all the isolates were screened after supplementation with various carbon sources, in which strain Scenedesmus sp. BHU1 was found highly effective among all. The efficacy of Scenedesmus sp. BHU1 strain under different sodium bicarbonate (4–20 mM) concentration, in which higher growth 1.4 times greater than control was observed at the concentration 12 mM sodium bicarbonate. In addition, total chlorophyll content (Chl-a + Chl-b), chlorophyll fluorescence (Fv/Fm, Y(II), ETR max, and NPQmax), and biomass productivity were found to be 11.514 μg/ml, 0.673, 0.675, and 31.167 μmol electrons m−2 s−1, 1.399, 59.167 mg/L/day, respectively, at the 12 mM sodium bicarbonate. However, under optimum sodium bicarbonate supplementation, 56.920% carbohydrate and 34.693% lipid content were accumulated, which showed potential of sodium bicarbonate supplementation in renewable biofuel feedstock by using Scenedesmus sp. BHU1 strain.
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Affiliation(s)
- Rahul Prasad Singh
- Laboratory of Algal Research, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Priya Yadav
- Laboratory of Algal Research, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Ajay Kumar
- Laboratory of Algal Research, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Abeer Hashem
- Botany and Microbiology Department, College of Science, King Saud University, Riyadh, Saudi Arabia
| | | | - Elsayed Fathi Abd Allah
- Plant Production Department, College of Food and Agricultural Sciences, King Saud University, Riyadh, Saudi Arabia
| | | | - Rajan Kumar Gupta
- Laboratory of Algal Research, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, India
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Yadav N, Gupta N, Singh DP. Ameliorating Effect of Bicarbonate on Salinity Induced Changes in the Growth, Nutrient Status, Cell Constituents and Photosynthetic Attributes of Microalga Chlorella vulgaris. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2022; 108:491-499. [PMID: 33594450 DOI: 10.1007/s00128-021-03135-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 01/29/2021] [Indexed: 06/12/2023]
Abstract
The cells of Chlorella vulgaris exhibited NaCl (0-400 mM) induced decrease in the growth, protein, chlorophyll, carbohydrate and total organic carbon, whereas total lipid and proline content increased with rising level of NaCl. Addition of NaHCO3 (20 mM) exhibited antagonistic effect against the adverse effect of salinity on the growth, level of macromolecules except proline. The SEM-EDS analysis of NaCl treated cells exhibited morphological variations as well as reduced accumulation of Na and Cl due to the presence of NaHCO3. The results on chlorophyll fluorescence induction kinetics revealed NaCl induced decline in the photosynthetic performance and quantum yield, while non-photochemical quenching of chlorophyll was enhanced, particularly at lower concentrations of NaCl. Addition of NaHCO3 to NaCl treated cells exhibited further increase in the non-photochemical quenching values. Thus, these results demonstrated that adverse impact of NaCl on the C. vulgaris cells was significantly mitigated in the presence of bicarbonate.
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Affiliation(s)
- Nisha Yadav
- Department of Environmental Science, BabasahebBhimraoAmbedkar University, VidyaVihar, Raebareli Road, Lucknow, UP, 226025, India
| | - Neha Gupta
- Department of Environmental Science, BabasahebBhimraoAmbedkar University, VidyaVihar, Raebareli Road, Lucknow, UP, 226025, India
| | - D P Singh
- Department of Environmental Science, BabasahebBhimraoAmbedkar University, VidyaVihar, Raebareli Road, Lucknow, UP, 226025, India.
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Enhancement of Pigments Production by Nannochloropsis oculata Cells in Response to Bicarbonate Supply. SUSTAINABILITY 2021. [DOI: 10.3390/su132111904] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In this study, the effects of bicarbonate addition on growth and pigment contents of the unicellular microalga Nannochloropsis oculata, were evaluated. N. oculata represents an interesting source of biomolecules widely used for food supplements and nutraceuticals. The bicarbonate was supplemented to microalgae cultures at concentrations of 0, 6, 18, 30, 42 and 60 mM. The cultures supplemented with salt at highest concentrations (42 and 60 mM) showed a significant increase in algal growth, demonstrated by the optical density spread. The intracellular content of pigments such as chlorophyll a and total carotenoids reached the highest values in cells from cultures supplied with bicarbonate. In fact, concentrations of bicarbonate from 30 to 60 mM strongly improved, for a short period of only 72 h, the cellular levels of chlorophylls and carotenoids. These are interesting pigments with commercial applications. The utilization of bicarbonate could represent an interesting sustainable opportunity to improve microalgae cultivation for cellular growth and pigment contents.
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Utilisation of CO2 from Sodium Bicarbonate to Produce Chlorella vulgaris Biomass in Tubular Photobioreactors for Biofuel Purposes. SUSTAINABILITY 2021. [DOI: 10.3390/su13169118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Microalgae are one of the most promising sources of renewable substrates used for energy purposes. Biomass and components accumulated in their cells can be used to produce a wide range of biofuels, but the profitability of their production is still not at a sufficient level. Significant costs are generated, i.a., during the cultivation of microalgae, and are connected with providing suitable culture conditions. This study aims to evaluate the possibility of using sodium bicarbonate as an inexpensive alternative CO2 source in the culture of Chlorella vulgaris, promoting not only the increase of microalgae biomass production but also lipid accumulation. The study was carried out at technical scale using 100 L photobioreactors. Gravimetric and spectrophotometric methods were used to evaluate biomass growth. Lipid content was determined using a mixture of chloroform and methanol according to the Blight and Dyer method, while the carbon content and CO2 fixation rate were measured according to the Walkley and Black method. In batch culture, even a small addition of bicarbonate resulted in a significant (p ≤ 0.05) increase in the amount of biomass, productivity and optical density compared to non-bicarbonate cultures. At 2.0 g∙L–1, biomass content was 572 ± 4 mg·L−1, the maximum productivity was 7.0 ± 1.0 mg·L–1·d–1, and the optical density was 0.181 ± 0.00. There was also an increase in the lipid content (26 ± 4%) and the carbon content in the biomass (1322 ± 0.062 g∙dw–1), as well as a higher rate of carbon dioxide fixation (0.925 ± 0.073 g·L–1·d–1). The cultivation of microalgae in enlarged scale photobioreactors provides a significant technological challenge. The obtained results can be useful to evaluate the efficiency of biomass and valuable cellular components production in closed systems realized at industrial scale.
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Ammonium Utilization in Microalgae: A Sustainable Method for Wastewater Treatment. SUSTAINABILITY 2021. [DOI: 10.3390/su13020956] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
In plant cells, ammonium is considered the most convenient nitrogen source for cell metabolism. However, despite ammonium being the preferred N form for microalgae, at higher concentrations, it can be toxic, and can cause growth inhibition. Microalgae’s tolerance to ammonium depends on the species, with various taxa showing different thresholds of tolerability and symptoms of toxicity. In the environment, ammonium at high concentrations represents a dangerous pollutant. It can affect water quality, causing numerous environmental problems, including eutrophication of downstream waters. For this reason, it is important to treat wastewater and remove nutrients before discharging it into rivers, lakes, or seas. A valid and sustainable alternative to conventional treatments could be provided by microalgae, coupling the nutrient removal from wastewater with the production of valuable biomass. This review is focused on ammonium and its importance in algal nutrition, but also on its problematic presence in aquatic systems such as wastewaters. The aim of this work is to provide recent information on the exploitation of microalgae in ammonium removal and the role of ammonium in microalgae metabolism.
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Chlorella sorokiniana Dietary Supplementation Increases Antioxidant Capacities and Reduces Ros Release in Mitochondria of Hyperthyroid Rat Liver. Antioxidants (Basel) 2020; 9:antiox9090883. [PMID: 32957734 PMCID: PMC7555375 DOI: 10.3390/antiox9090883] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 09/02/2020] [Accepted: 09/15/2020] [Indexed: 01/06/2023] Open
Abstract
The ability of aerobic organisms to cope with the attack of radicals and other reactive oxygen species improves by feeding on foods containing antioxidants. Microalgae contain many molecules showing in vitro antioxidant capacity, and their food consumption can protect cells from oxidative insults. We evaluated the capacity of dietary supplementation with 1% dried Chlorella sorokiniana strain 211/8k, an alga rich in glutathione, α-tocopherol, and carotenoids, to counteract an oxidative attack in vivo. We used the hyperthyroid rat as a model of oxidative stress, in which the increase in metabolic capacities is associated with an increase in the release of mitochondrial reactive oxygen species (ROS) and the susceptibility to oxidative insult. Chlorella sorokiniana supplementation prevents the increases in oxidative stress markers and basal oxygen consumption in hyperthyroid rat livers. It also mitigates the thyroid hormone-induced increase in maximal aerobic capacities, the mitochondrial ROS release, and the susceptibility to oxidative stress. Finally, alga influences the thyroid hormone-induced changes in the factors involved in mitochondrial biogenesis peroxisomal proliferator-activated receptor-γ coactivator (PGC1-1) and nuclear respiratory factor 2 (NRF-2). Our results suggest that Chlorella sorokiniana dietary supplementation has beneficial effects in counteracting oxidative stress and that it works primarily by preserving mitochondrial function. Thus, it can be useful in preventing dysfunctions in which mitochondrial oxidative damage and ROS production play a putative role.
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