Characterization of Fatty Acid EXporters involved in fatty acid transport for oil accumulation in the green alga Chlamydomonas reinhardtii

Abstract

BackgroundIn the past few decades, microalgae biofuel has become one of the most interesting sources of renewable energy. However, the higher cost of microalgae biofuel compared to that of petroleum prevented microalgae biofuel production. Therefore, the research on increasing lipid productivity from microalgae becomes more important. The lipid production source, triacylglycerol biosynthesis in microalgae requires short chain fatty acids as substrates, which are synthesized in chloroplasts. However, the transport mechanism of fatty acids from microalgae chloroplasts to cytosol remains unknown.ResultscDNAs from two homologs of the Arabidopsis fatty acid exporter 1 (FAX1) were cloned from Chlamydomonas reinhardtii and were named crfax1 and crfax2. Both CrFAXs were involved in fatty acid transport, and their substrates were mainly C16 and C18 fatty acids. Overexpression of both CrFAXs increased the accumulation of the total lipid content in algae cells, and the fatty acid compositions were changed under normal TAP or nitrogen deprivation conditions. Overexpression of both CrFAXs also increased the chlorophyll content. The MGDG content was decreased but the TAG, DAG, DGDG and other lipid contents were increased in CrFAXs overexpression strains.ConclusionThese results reveal that CrFAX1 and CrFAX2 were involved in mediating fatty acid export for lipids biosynthesis in C. reinhardtii. In addition, overexpression of both CrFAXs obviously increased the intracellular lipid content, especially the triacylglycerol content in microalgae, which provides a potential technology for the production of more biofuels using microalgae.Electronic supplementary materialThe online version of this article (10.1186/s13068-018-1332-4) contains supplementary material, which is available to authorized users.

Two splice variants of the DsMEK1 mitogen-activated protein kinase kinase (MAPKK) is involved different way in salt stress regulation in Dunaliella salina

“…and DsMEK1-X2 gene were performed in those lines, which confirmed that the related genes were overexpressed or knock down ( Fig. 5C) [35].…”

Morpho-taxonomic, genetic, and biochemical characterization of freshwater microalgae as potential biodiesel feedstock

“…Thus, to use algae as an efficient alternative energy source for biodiesel production, the challenge remains to increase both lipid productivity and biomass concentration. Meanwhile, there have been other efforts to increase biomass production as well as the lipid content of a microalgae through various genomic and proteomic approaches that will uncover the biological implications and pave the future tailored manipulation of microalgae for broader industrial applications (Anand et al 2017;Banerjee et al 2017;Li et al 2019). However, for any kind of modifications to be made at the molecular level, the first step is to screen microalgae strains from different habitats and examine them for their inherent properties to be used as an ideal strain for biodiesel production (Jagadevan et al 2018).…”

Two splice variants of the DsMEK1 mitogen-activated protein kinase kinase (MAPKK) are involved in salt stress regulation in Dunaliella salina in different ways

“…qRT-PCR assays of the DsMEK1-X1 and DsMEK1-X2 genes were performed in those lines, which confirmed that the related genes were overexpressed or knockdown ( Fig. 5c) [28].…”