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Niemi C, Gentili FG. Fatty acid analysis in microalgal mono- and polycultures using diffuse reflectance infrared Fourier transform spectroscopy coupled with partial least squares analysis. Heliyon 2024; 10:e33058. [PMID: 38988580 PMCID: PMC11234097 DOI: 10.1016/j.heliyon.2024.e33058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 06/11/2024] [Accepted: 06/13/2024] [Indexed: 07/12/2024] Open
Abstract
Fatty acids are of particular interest for industrial applications of microalgal feedstock, as these have a wide array of different uses such as pharmaceuticals and biofuels. Fourier transform infrared (FTIR) spectroscopic techniques used in combination with multivariate prediction modeling are showing great potential as analytical methods for characterizing microalgal biomass. The present study investigated the use of diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) coupled with partial least squares regression (PLSR) to estimate fatty acid contents in microalgae. A prediction model for microalgal samples was developed using algae cultivated in both Bold's basal medium (BBM) and sterilized municipal wastewater under axenic conditions, as well as algal polycultures cultivated in open raceway ponds using untreated municipal wastewater influent. This universal prediction model was able to accurately predict microalgal samples of either type with high accuracy (RMSEP = 1.38, relative error = 0.14) and reliability (R2 > 0.92). DRIFTS in combination with PLSR is a rapid method for determining fatty acid contents in a wide variety of different microalgal samples with high accuracy. The use of spectral characterization techniques offers a reliable and environmentally friendly alternative to traditional labor intensive techniques based on the use of toxic chemicals.
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Affiliation(s)
- Calle Niemi
- Department of Forest Biomaterials and Technology, Swedish University of Agricultural Sciences, 901 83, Umeå, Sweden
| | - Francesco G. Gentili
- Department of Forest Biomaterials and Technology, Swedish University of Agricultural Sciences, 901 83, Umeå, Sweden
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Toxic Effect of Metal Doping on Diatoms as Probed by Broadband Terahertz Time-Domain Spectroscopy. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27185897. [PMID: 36144633 PMCID: PMC9504612 DOI: 10.3390/molecules27185897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 09/04/2022] [Accepted: 09/06/2022] [Indexed: 11/19/2022]
Abstract
The global marine environment is increasingly affected by human activities causing climate change, eutrophication, and pollution. These factors influence the metabolic mechanisms of phytoplankton species, such as diatoms. Among other pollutant agents, heavy metals can have dramatic effects on diatom viability. Detailed knowledge of the interaction of diatoms with metals is essential from both a fundamental and applicative point of view. To this aim, we assess terahertz time-domain spectroscopy as a tool for sensing the diatoms in aqueous systems which mimic their natural environment. Despite the strong absorption of terahertz radiation in water, we show that diatoms can be sensed by probing the water absorption enhancement in the terahertz range caused by the water–diatom interaction. We reveal that the addition of metal dopants affects this absorption enhancement, thus enabling the monitoring of the toxic effects of metals on diatoms using terahertz spectroscopy. We demonstrate that this technique can detect the detrimental effects of heavy metals earlier than conventional methods such as microscopy, enzymatic assays, and molecular analyses aimed at assessing the overexpression of genes involved in the heavy metal-stress response.
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Deniset-Besseau A, Coat R, Moutel B, Rebois R, Mathurin J, Grizeau D, Dazzi A, Gonçalves O. Revealing Lipid Body Formation and its Subcellular Reorganization in Oleaginous Microalgae Using Correlative Optical Microscopy and Infrared Nanospectroscopy. APPLIED SPECTROSCOPY 2021; 75:1538-1547. [PMID: 34608808 DOI: 10.1177/00037028211050659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The purpose of this work is to develop an integrated imaging approach to characterize without labeling at the sub-cellular level the formation of lipid body droplets (LBs) in microalgae undergoing nitrogen starvation. First conventional optical microscopy approaches, gas chromatography, and turbidimetry measurements allowed to monitor the biomass and the total lipid content in the oleaginous microalgae Parachlorella kesslerii during the starvation process. Then a local analysis of the LBs was proposed using an innovative infrared nanospectroscopy technique called atomic force microscopy-based infrared spectroscopy (AFM-IR). This label-free technique assessed the formation of LBs and allowed to look into the LB composition thanks to the acquisition of local infrared spectra. Last correlative measurements using fluorescence microscopy and AFM-IR were performed to investigate the subcellular reorganization of LB and the chloroplasts.
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Affiliation(s)
| | - Rémy Coat
- LUNAM Université, Université de Nantes, GEPEA, UMR CNRS-6144, Saint-Nazaire Cedex, France
| | - Benjamin Moutel
- LUNAM Université, Université de Nantes, GEPEA, UMR CNRS-6144, Saint-Nazaire Cedex, France
| | - Rolando Rebois
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR 8000, Orsay, France
| | - Jérémie Mathurin
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR 8000, Orsay, France
| | - Dominique Grizeau
- LUNAM Université, Université de Nantes, GEPEA, UMR CNRS-6144, Saint-Nazaire Cedex, France
| | - Alexandre Dazzi
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR 8000, Orsay, France
| | - Olivier Gonçalves
- LUNAM Université, Université de Nantes, GEPEA, UMR CNRS-6144, Saint-Nazaire Cedex, France
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Bouillaud D, Drouin D, Charrier B, Jacquemmoz C, Farjon J, Giraudeau P, Gonçalves O. Using benchtop NMR spectroscopy as an online non-invasive in vivo lipid sensor for microalgae cultivated in photobioreactors. Process Biochem 2020. [DOI: 10.1016/j.procbio.2020.03.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Cointet E, Wielgosz-Collin G, Bougaran G, Rabesaotra V, Gonçalves O, Méléder V. Effects of light and nitrogen availability on photosynthetic efficiency and fatty acid content of three original benthic diatom strains. PLoS One 2019; 14:e0224701. [PMID: 31694047 PMCID: PMC6834396 DOI: 10.1371/journal.pone.0224701] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 10/19/2019] [Indexed: 12/17/2022] Open
Abstract
Microalgal biotechnology has gained considerable importance in recent decades. Applications range from simple biomass production for food and animal feed to valuable products for fuel, pharmaceuticals, health, biomolecules and materials relevant to nanotechnology. There are few reports of the exploration of wider microalgae biodiversity in the literature on high value microalgal compounds, however, because it is believed that there is little to be gained in terms of biomass productivity by examining new strains. Still, without diversity, innovation in biotechnology applications is currently limited. Using microalgal diversity is a very promising way to match species and processes for a specific biotechnological application. In this context, three benthic marine diatom strains (Entomoneis paludosa NCC18.2, Nitzschia alexandrina NCC33, and Staurosira sp NCC182) were selected for their lipid production and growth capacities. Using PAM fluorometry and FTIR spectroscopy, this study investigated the impact of nitrogen repletion and depletion as well as light intensity (30, 100, and 400 μmol.photons.m-2.s-1) on their growth, photosynthetic performance and macromolecular content, with the aim of improving the quality of their lipid composition. Results suggest that under high light and nitrogen limitation, the photosynthetic machinery is negatively impacted, leading cells to reduce their growth and accumulate lipids and/or carbohydrates. However, increasing lipid content under stressful conditions does not increase the production of lipids of interest: PUFA, ARA and EPA production decreases. Culture conditions to optimize production of such fatty acids in these three original strains led to a balance between economic and ecophysiological constraints: low light and no nitrogen limitation led to better photosynthetic capacities associated with energy savings, and hence a more profitable approach.
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Affiliation(s)
- Eva Cointet
- Université de Nantes, Laboratoire Mer Molécules Santé, Nantes, France
- * E-mail:
| | | | | | - Vony Rabesaotra
- Université de Nantes, Laboratoire Mer Molécules Santé, Nantes, France
| | | | - Vona Méléder
- Université de Nantes, Laboratoire Mer Molécules Santé, Nantes, France
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Benchtop flow NMR spectroscopy as an online device for the in vivo monitoring of lipid accumulation in microalgae. ALGAL RES 2019. [DOI: 10.1016/j.algal.2019.101624] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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7
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Cointet E, Wielgosz-Collin G, Méléder V, Gonçalves O. Lipids in benthic diatoms: A new suitable screening procedure. ALGAL RES 2019. [DOI: 10.1016/j.algal.2019.101425] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Podevin M, Fotidis IA, Angelidaki I. Microalgal process-monitoring based on high-selectivity spectroscopy tools: status and future perspectives. Crit Rev Biotechnol 2017; 38:704-718. [DOI: 10.1080/07388551.2017.1398132] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Michael Podevin
- Department of Environmental Engineering, Technical University of Denmark, Lyngby, Denmark
| | - Ioannis A. Fotidis
- Department of Environmental Engineering, Technical University of Denmark, Lyngby, Denmark
| | - Irini Angelidaki
- Department of Environmental Engineering, Technical University of Denmark, Lyngby, Denmark
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Compositional profiles of Rhodosporidium toruloides cells under nutrient limitation. Appl Microbiol Biotechnol 2017; 101:3801-3809. [DOI: 10.1007/s00253-017-8157-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 01/21/2017] [Accepted: 01/25/2017] [Indexed: 01/18/2023]
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10
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Pulsed electric field and pH assisted selective extraction of intracellular components from microalgae Nannochloropsis. ALGAL RES 2015. [DOI: 10.1016/j.algal.2015.01.014] [Citation(s) in RCA: 140] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Havlik I, Scheper T, Reardon KF. Monitoring of Microalgal Processes. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2015; 153:89-142. [PMID: 26289537 DOI: 10.1007/10_2015_328] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Process monitoring, which can be defined as the measurement of process variables with the smallest possible delay, is combined with process models to form the basis for successful process control. Minimizing the measurement delay leads inevitably to employing online, in situ sensors where possible, preferably using noninvasive measurement methods with stable, low-cost sensors. Microalgal processes have similarities to traditional bioprocesses but also have unique monitoring requirements. In general, variables to be monitored in microalgal processes can be categorized as physical, chemical, and biological, and they are measured in gaseous, liquid, and solid (biological) phases. Physical and chemical process variables can be usually monitored online using standard industrial sensors. The monitoring of biological process variables, however, relies mostly on sensors developed and validated using laboratory-scale systems or uses offline methods because of difficulties in developing suitable online sensors. Here, we review current technologies for online, in situ monitoring of all types of process parameters of microalgal cultivations, with a focus on monitoring of biological parameters. We discuss newly introduced methods for measuring biological parameters that could be possibly adapted for routine online use, should be preferably noninvasive, and are based on approaches that have been proven in other bioprocesses. New sensor types for measuring physicochemical parameters using optical methods or ion-specific field effect transistor (ISFET) sensors are also discussed. Reviewed methods with online implementation or online potential include measurement of irradiance, biomass concentration by optical density and image analysis, cell count, chlorophyll fluorescence, growth rate, lipid concentration by infrared spectrophotometry, dielectric scattering, and nuclear magnetic resonance. Future perspectives are discussed, especially in the field of image analysis using in situ microscopy, infrared spectrophotometry, and software sensor systems.
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Affiliation(s)
- Ivo Havlik
- Institute of Technical Chemistry, Leibniz University Hannover, Callinstrasse 5, 30167, Hannover, Germany.
| | - Thomas Scheper
- Institute of Technical Chemistry, Leibniz University Hannover, Callinstrasse 5, 30167, Hannover, Germany
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