Metabolite Quantification by Fourier Transform Infrared Spectroscopy in Diatoms: Proof of Concept on Phaeodactylum tricornutum

Abstract

Diatoms are feedstock for the production of sustainable biocommodities, including biofuel. The biochemical characterization of newly isolated or genetically modified strains is seminal to identify the strains that display interesting features for both research and industrial applications. Biochemical quantification of organic macromolecules cellular quotas are time-consuming methodologies which often require large amount of biological sample. Vibrational spectroscopy is an essential tool applied in several fields of research. A Fourier transform infrared (FTIR) microscopy-based imaging protocol was developed for the simultaneous cellular quota quantification of lipids, carbohydrates, and proteins of the diatom Phaeodactylum tricornutum. The low amount of sample required for the quantification allows the high throughput quantification on small volume cultures. A proof of concept was performed (1) on nitrogen-starved experimental cultures and (2) on three different P. tricornutum wild-type strains. The results are supported by the observation in situ of lipid droplets by confocal and brightfield microscopy. The results show that major differences exist in the regulation of lipid metabolism between ecotypes of P. tricornutum.

Romanian Viscum album L.—Untargeted Low-Molecular Metabolomic Approach to Engineered Viscum–AuNPs Carrier Assembly

“…The spectra of nanoparticle carrier assembly ( Figure 3 a) show the characteristic absorption bands of the viscum sample as well as the AuNPs coated with a surfactant (trisodium citrate) ( Figure 3 a,b). In addition, the peaks at 1622, 1371, 1258, 1114, and 660 cm −1 were found in the synthesized AuNP solution ( Figure 3 a) and are shifted to higher wavenumbers (1641, 1382, 1267, 1153 and 671 cm −1 ), indicating binding of nanoparticles to the functional groups O–H, C=O, C–N, C–S, and C–O belonging to the various phytoconstituents ( Figure 3 a,b and Table 3 ) [ 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 ]. In particular, the hydroxyl group is considered to be involved in the binding of AuNPs [ 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 ].…”

“…In addition, the peaks at 1622, 1371, 1258, 1114, and 660 cm −1 were found in the synthesized AuNP solution (Figure 3a) and are shifted to higher wavenumbers (1641, 1382, 1267, 1153 and 671 cm −1 ), indicating binding of nanoparticles to the functional groups O-H, C=O, C-N, C-S, and C-O belonging to the various phytoconstituents (Figure 3a,b and Table 3) [79][80][81][82][83][84][85][86][87][88][89][90][91]. In particular, the hydroxyl group is considered to be involved in the binding of AuNPs [85][86][87][88][89][90][91][92][93][94][95][96][97][98]. 3) [79][80][81][82][83][84][85][86][87][88][89][90][91].…”

“…In particular, the hydroxyl group is considered to be involved in the binding of AuNPs [85][86][87][88][89][90][91][92][93][94][95][96][97][98]. 3) [79][80][81][82][83][84][85][86][87][88][89][90][91]. In particular, the hydroxyl group is considered to be involved in the binding of AuNPs [85][86][87][88][89][90][91][92][93][94][95][96][97][98].…”

“…3) [79][80][81][82][83][84][85][86][87][88][89][90][91]. In particular, the hydroxyl group is considered to be involved in the binding of AuNPs [85][86][87][88][89][90][91][92][93][94][95][96][97][98]. Figure 4a shows the specific XRD spectrum of AuNPs.…”

Comparative Proteomic Analysis of the Diatom Phaeodactylum tricornutum Reveals New Insights Into Intra- and Extra-Cellular Protein Contents of Its Oval, Fusiform, and Triradiate Morphotypes

“…Previous studies attempted to understand P. tricornutum polymorphism and demonstrated that such morphogenesis is not dependent on P. tricornutum genotype but can be induced by environmental factors ( De Martino et al, 2007 ). Several works investigated recently the functional diversity of the ten ecotypes isolated from P. tricornutum that might also be a factor influencing the polymorphism ( Rastogi et al, 2018 , 2020 ; Song et al, 2020 ; Scarsini et al, 2021 ). The fusiform morphotype is the most frequent one in natural waters and in vitro cultures ( Volcani, 1981 ; De Martino et al, 2007 ).…”