Effects of rare earth elements on growth rate, lipids, fatty acids and pigments in microalgae

0479289 - MBÚ 2018 RIV US eng J - Journal Article
Goecke, Franz - Vítová, Milada - Lukavský, Jaromír - Nedbalová, L. - Řezanka, Tomáš - Zachleder, Vilém
Effects of rare earth elements on growth rate, lipids, fatty acids and pigments in microalgae.
Phycological Research. Roč. 65, č. 3 (2017), s. 226-234. ISSN 1322-0829. E-ISSN 1440-1835
R&D Projects: GA MŠMT(CZ) LO1416; GA TA ČR TE01020080; GA TA ČR TA03011027; GA ČR GA14-00227S
Institutional support: RVO:61388971 ; RVO:67985939
Keywords : carotenoids * chlorophylls * lanthanides
OECD category: Microbiology; Bioproducts (products that are manufactured using biological material as feedstock) biomaterials, bioplastics, biofuels, bioderived bulk and fine chemicals, bio-derived novel materials (BU-J)
Impact factor: 1.275, year: 2017

The extensive exploitation of rare earth elements (REEs), particularly in electronic technologies and agriculture has concomitantly raised the environmental load. Their resulting effects on primary producers such as microalgae are, however, poorly understood. We have studied these effects on two microalgae of biotechnological interest. The yellow-green alga Trachydiscus minutus (Eustigmatophyceae, Ochrophyta), and the green alga Parachlorella kessleri (Trebouxiophyceae, Chlorophyta) were cultivated in mineral medium supplemented with 10molL(-1) chlorides of REEs: cerium, gadolinium, lanthanum, lutetium, praseodymium, scandium, and with monazite, which is a mineral rich in those elements. We observed growth rates at different mean light intensities (20, 50, 150 and 300molm(-2)s(-1)). The high growth rate of P. kessleri was not affected by the presence of any lanthanide, and decreased proportionally with light intensity (from 0.2 to 0.04 doublings per hour). In contrast, the growth rate of T. minutus was about three times lower compared with P. kessleri, with an optimum at 50molm(-2)s(-1) and decreased at higher or lower light intensities. In the presence of Ce3+, La3+ and Sc3+, the growth rate markedly increased to a value that corresponded to the growth rate in P. kessleri at the same light intensity. The composition and content of pigments and lipids were followed at the optimum light intensity for both species. The lipid content (percentage of dry weight) varied only slightly in the presence of individual rare earths. There was, however, an increase in saturated fatty acids at the expense of polyunsaturated fatty acids. The effect of REEs on pigments was variable: the presence of Ce3+, Gd3+, La3+ and Sc3+ caused an increase in the concentrations of major pigments such as lutein, violaxanthin, -carotene or chlorophylls, while Pr3+ and Lu3+ reduced them.
Permanent Link: http://hdl.handle.net/11104/0275293