{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,3]],"date-time":"2026-06-03T19:38:42Z","timestamp":1780515522520,"version":"3.54.1"},"reference-count":34,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2010,9,17]],"date-time":"2010-09-17T00:00:00Z","timestamp":1284681600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Algae are becoming a strategic source of fuels, food, feedstocks, and biologically active compounds. This potential has stimulated the development of innovative analytical methods focused on these microorganisms. Algal lipids are among the most promising potential products for fuels as well as for nutrition. The crucial parameter characterizing the algal lipids is the degree of unsaturation of the constituent fatty acids quantified by the iodine value. Here we demonstrate the capacity of the spatially resolved Raman microspectroscopy to determine the effective iodine value in lipid storage bodies of individual living algal cells. The Raman spectra were collected from three selected algal species immobilized in an agarose gel. Prior to immobilization, the algae were cultivated in the stationary phase inducing an overproduction of lipids. We employed the characteristic peaks in the Raman scattering spectra at 1,656 cm\u22121 (cis C=C stretching mode) and 1,445 cm\u22121 (CH2 scissoring mode) as the markers defining the ratio of unsaturated-to-saturated carbon-carbon bonds of the fatty acids in the algal lipids. These spectral features were first quantified for pure fatty acids of known iodine value. The resultant calibration curve was then used to calculate the effective iodine value of storage lipids in the living algal cells from their Raman spectra. We demonstrated that the iodine value differs significantly for the three studied algal species. Our spectroscopic estimations of the iodine value were validated using GC-MS measurements and an excellent agreement was found for the Trachydiscus minutus species. A good agreement was also found with the earlier published data on Botryococcus braunii. Thus, we propose that Raman microspectroscopy can become technique of choice in the rapidly expanding field of algal biotechnology.<\/jats:p>","DOI":"10.3390\/s100908635","type":"journal-article","created":{"date-parts":[[2010,9,19]],"date-time":"2010-09-19T09:41:46Z","timestamp":1284889306000},"page":"8635-8651","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":157,"title":["Raman Microspectroscopy of Individual Algal Cells: Sensing Unsaturation of Storage Lipids in vivo"],"prefix":"10.3390","volume":"10","author":[{"given":"Ota","family":"Samek","sequence":"first","affiliation":[{"name":"Institute of Scientific Instruments of the AS CR, v.v.i., Academy of Sciences of the Czech Republic, Kralovopolska 147, 61264 Brno, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alexandr","family":"Jon\u00e1\u0161","sequence":"additional","affiliation":[{"name":"Institute of Scientific Instruments of the AS CR, v.v.i., Academy of Sciences of the Czech Republic, Kralovopolska 147, 61264 Brno, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zden\u011bk","family":"Pil\u00e1t","sequence":"additional","affiliation":[{"name":"Institute of Scientific Instruments of the AS CR, v.v.i., Academy of Sciences of the Czech Republic, Kralovopolska 147, 61264 Brno, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pavel","family":"Zem\u00e1nek","sequence":"additional","affiliation":[{"name":"Institute of Scientific Instruments of the AS CR, v.v.i., Academy of Sciences of the Czech Republic, Kralovopolska 147, 61264 Brno, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ladislav","family":"Nedbal","sequence":"additional","affiliation":[{"name":"Institute of Systems Biology and Ecology of the AS CR, v.v.i., Academy of Sciences of the Czech Republic, Z\u00e1mek 136, 37333 Nov\u00e9 Hrady, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jan","family":"T\u0159\u00edska","sequence":"additional","affiliation":[{"name":"Institute of Systems Biology and Ecology of the AS CR, v.v.i., Academy of Sciences of the Czech Republic, Z\u00e1mek 136, 37333 Nov\u00e9 Hrady, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Petr","family":"Kotas","sequence":"additional","affiliation":[{"name":"Institute of Systems Biology and Ecology of the AS CR, v.v.i., Academy of Sciences of the Czech Republic, Z\u00e1mek 136, 37333 Nov\u00e9 Hrady, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Martin","family":"Trt\u00edlek","sequence":"additional","affiliation":[{"name":"Photon Systems Instruments, Dr\u00e1sov 470, 664 24 Dr\u00e1sov, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2010,9,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1126\/science.281.5374.237","article-title":"Production of the biosphere: integrating terrestrial and oceanic components","volume":"281","author":"Field","year":"1998","journal-title":"Science"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1007\/s12155-008-9008-8","article-title":"Second generation biofuels: high-efficiency microalgae for biodiesel production","volume":"1","author":"Schenk","year":"2008","journal-title":"Bioenerg. Res"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"821","DOI":"10.1007\/s10295-009-0559-2","article-title":"Neochloris oleabundans UTEX#1185: A suitable renewable lipid source for biofuel production","volume":"36","author":"Gouveia","year":"2009","journal-title":"J. Ind. Microbiol. Biotechnol"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"269","DOI":"10.1007\/s10295-008-0495-6","article-title":"Microalgae as a raw material for biofuels production","volume":"36","author":"Gouveia","year":"2009","journal-title":"J. Ind. Microbiol. Biotechnol"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"198","DOI":"10.1016\/j.jbiosc.2009.08.004","article-title":"Visualizing \u201cgreen oil\u201d in live algal cells","volume":"109","author":"Cooper","year":"2010","journal-title":"J. Biosci. Bioeng"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1016\/j.mimet.2009.01.001","article-title":"A high throughput Nile red method for quantitative measurement of neutral lipids in microalgae","volume":"77","author":"Chen","year":"2009","journal-title":"J. Microbiol. Meth"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1016\/S0167-7012(02)00127-6","article-title":"Identification of medically relevant microorganisms by vibrational spectroscopy","volume":"51","author":"Maquelin","year":"2002","journal-title":"J. Microbiol. Meth"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1543","DOI":"10.1039\/b507715j","article-title":"Micro-Raman spectroscopic identification of bacterial cells of the genus Staphylococcus and dependence on their cultivation conditions","volume":"130","author":"Harz","year":"2005","journal-title":"Analyst"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"378","DOI":"10.1002\/lapl.200910154","article-title":"The potential of Raman spectroscopy for the identification of biofilm formation by Staphylococcus epidermidis","volume":"5","author":"Samek","year":"2010","journal-title":"Laser Phys. Lett"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1133","DOI":"10.1002\/jrs.1734","article-title":"Reference database of Raman spectra of biological molecules","volume":"38","author":"Vandenabeele","year":"2007","journal-title":"J. Raman Spectrosc"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1343","DOI":"10.3390\/s7081343","article-title":"Raman spectroscopy cell-based biosensors","volume":"7","author":"Notingher","year":"2007","journal-title":"Sensors"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1871","DOI":"10.3390\/s100301871","article-title":"Raman spectroscopy and related techniques in biomedicine","volume":"10","author":"Downes","year":"2010","journal-title":"Sensors"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"493","DOI":"10.1080\/05704920701551530","article-title":"Raman spectroscopy of biological tissues","volume":"42","author":"Movasaghi","year":"2007","journal-title":"Appl. Spectrosc. Rev"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1111\/j.1574-6968.2007.00861.x","article-title":"In vivo prediction of the nutrient status of individual microalgal cells using Raman microspectroscopy","volume":"275","author":"Heraud","year":"2007","journal-title":"FEMS Microbiol. Lett"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1002\/cem.990","article-title":"Effect of pre-processing of Raman spectra on in vivo classification of nutrient status of microalgal cells","volume":"20","author":"Heraud","year":"2006","journal-title":"J. Chemometrics"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"889","DOI":"10.1002\/bit.22617","article-title":"Micro-Raman spectroscopy of algae: Composition analysis and fluorescence background behavior","volume":"105","author":"Huang","year":"2010","journal-title":"Biotechnol. Bioeng"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"265","DOI":"10.1007\/s12223-010-0039-0","article-title":"Trachydiscus minutus, a new biotechnological source of eicosapentaenoic acid","volume":"55","author":"Sigler","year":"2010","journal-title":"Folia Microbiol"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1007\/s12257-008-0171-8","article-title":"Evaluation of extraction methods for recovery of fatty acids from Botryococcus braunii LB572 and Synechocystis sp. PCC 6803","volume":"14","author":"Tran","year":"2009","journal-title":"Biotechnol. Bioprocess Eng"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"494","DOI":"10.1007\/BF02582487","article-title":"Raman spectroscopic analysis of the cis\/trans isomer composition of edible vegetable oils","volume":"49","author":"Bailey","year":"1972","journal-title":"J. Am. Oil. Chem. Soc"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"483","DOI":"10.1007\/BF02540752","article-title":"Determination of the total unsaturation in oils and margarines by Fourier Transform Raman spectroscopy","volume":"67","author":"Hendra","year":"1990","journal-title":"J. Am. Oil. Chem. Soc"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1503","DOI":"10.1366\/000370292789619368","article-title":"Potential of near-infrared Fourier Transform Raman spectroscopy in food analysis","volume":"46","author":"Ozaki","year":"1992","journal-title":"Appl. Spectrosc"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1002\/lite.200700091","article-title":"Iodine value and biodiesel: Is limitation still appropriate?","volume":"19","author":"Schober","year":"2007","journal-title":"Lipid Techn"},{"key":"ref_23","unstructured":"Setlik, I (1966). Contamination of algal cultures by heterotrophic microorganisms and its prevention. Ann Rep Algol Trebon, 89\u2013100."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"965","DOI":"10.1083\/jcb.100.3.965","article-title":"Nile red: A selective fluorescent stain for intracellular lipid droplets","volume":"100","author":"Greenspan","year":"1995","journal-title":"J. Cell Biol"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"639","DOI":"10.1016\/j.mimet.2006.11.008","article-title":"Fluorescent measurement of microalgal neutral lipids","volume":"68","author":"Elsey","year":"2007","journal-title":"J. Microbiol. Meth"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1023\/A:1007972214462","article-title":"Characterization of the growth and lipid content of the diatom Chaetoceros muelleri","volume":"9","author":"McGinnis","year":"1997","journal-title":"J. Appl. Phycol"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"714111","DOI":"10.1117\/12.822382","article-title":"Raman microspectrometry of optically trapped micro- and nanoobjects","volume":"7141","author":"Jonas","year":"2008","journal-title":"Proc. SPIE"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Pawley, JB (2006). Handbook of Biological Confocal Microscopy, Springer Science. [3rd ed].","DOI":"10.1007\/978-0-387-45524-2"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2391","DOI":"10.1105\/tpc.108.064154","article-title":"Defining the far-red limit of photosystem II in Spinach","volume":"21","author":"Thapper","year":"2009","journal-title":"Plant Cell"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"288","DOI":"10.1366\/000370206776342553","article-title":"Optimization of the rolling-circle filter for Raman background subtraction","volume":"60","author":"Brandt","year":"2006","journal-title":"Appl. Spectrosc"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1445","DOI":"10.1007\/s11746-998-0197-2","article-title":"Calculating the iodine Value for marine oils fatty acid profiles","volume":"75","author":"Ham","year":"1998","journal-title":"J. Am. Oil. Chem. Soc"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1146","DOI":"10.1016\/j.cep.2009.03.006","article-title":"Effect of temperature and nitrogen concentration on the growth and lipid content of Nannochloropsis oculata and Chlorella vulgaris for biodiesel production","volume":"48","author":"Converti","year":"2009","journal-title":"Chem. Eng. Proc"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"4717","DOI":"10.1016\/j.biortech.2007.09.073","article-title":"Effect of iron on growth and lipid accumulation in Chlorella vulgaris","volume":"99","author":"Liu","year":"2008","journal-title":"Biores. Technol"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"87","DOI":"10.1016\/j.biombioe.2006.05.001","article-title":"Autotrophic cultivation of Botryococcus braunii for the production of hydrocarbons and exopolysaccharides in various media","volume":"31","author":"Dayanandaa","year":"2007","journal-title":"Biomass Bioenerg"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/10\/9\/8635\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T22:03:23Z","timestamp":1760220203000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/10\/9\/8635"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2010,9,17]]},"references-count":34,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2010,9]]}},"alternative-id":["s100908635"],"URL":"https:\/\/doi.org\/10.3390\/s100908635","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2010,9,17]]}}}