An axenic strain reveals the responses of Phaeodactylum tricornutum to external organic carbon

The model diatom Phaeodactylum tricornutum is considered a promising source of various high value bioproducts,and developing cultivation processes is crucial for its commercialization.Although mixotrophy and heterotrophy have been recommended as effective strategies for microalgal cultivation,previous studies on P.tricornutum have yielded conflicting results in terms of cultivating this microalga.To verify the capacity of this microalga utilizing external organic carbon,both heterotrophic and mixotrophic cultivation with varied carbon sources were performed using an axenic strain.The results demonstrate that glycerol was the only organic carbon that substantially stimulated the growth of P.tricornutum in the presence of light.Sodium acetate(NaAc)at low concentrations could also promote growth,while at high concentrations led to severe inhibition under mixotrophic conditions.The addition of glucose imposed no appreciable impact on either cell density or biomass concentration,confirming that P.tricornutum cannot metabolize external glucose.Subsequently,a comparative analysis between mixotrophy and autotrophy was performed to reveal the influences of glycerol on the cellular metabolism based on growth performances,biochemical compositions,and chlorophyll fluorescence parameters.Results also indicate that the addition of glycerol did not have detrimental effects on the capacity of either pigments biosynthesis or photosynthesis,but enhanced the saturated fatty acids and reduced the unsaturated fatty acids.

Protein Disulfide Isomerase and Its Potential Function on Endoplasmic Reticulum Quality Control in Diatom Phaeodactylum tricornutum

PDI is a molecular chaperone and plays an important role in Endoplasmic Reticulum quality control (ERQC).PDI participates in the refolding of the misfolded/unfolded proteins to maintain cellular homeostasis under differentstresses. However, bioinformatic characteristics and potential functions of PDIs in diatom Phaeodactylumtricornutum (Pt) are still unknown so far. Hence, the genome-wide characteristics of PtPDI proteins in P. tricornutumwere first studied via bioinformatic and transcriptomic methods. 42 PtPDI genes were identified from thegenome of P. tricornutum. The motif, protein structure, classification, number of introns, phylogenetic relationship,and the expression level of 42 PtPDI genes under the tunicamycin stress were analyzed. A pair of tandemduplicated genes (PtPDI15 and PtPDI18) was observed in P. tricornutum. The 42 PtPDIs with different genecharacteristics were divided into three independent clades, indicating different evolutional relationships and functionsof these PtPDIs. The 14 up-regulated PtPDI genes under the tunicamycin treatment might have a positiveeffect on the ER quality control of the unfolded/misfolded proteins, while the 7 down-regulated PtPDIs mightnegatively affect the ERQC. The characteristics of all 42 PtPDIs and their proposed working model here providea comprehensive understanding of the PtPDIs gene family. The differential expression of 21 PtPDIs will be usefulfor further functional study in the ERQC.

Impact of Different Light Characteristics on the Growth and Lipid Content of Diatom Phaeodactylum tricornutum Transconjugant Strains

Light regulates important metabolic processes in microalgal cells, which can further impact the metabolism and the accumulation of biomolecules such as lipids, carbohydrates, and proteins. Different characteristics of light have been studied on various strains of the model diatom Phaeodactylum tricornutum, but not on transconjugant cells and information on wild-type strains is still limited. Therefore, we studied the impact of different light characteristics such as spectral quality, light intensity and light shift on the growth, and the composition in lipids and fatty acids of P. tricornutum cells to provide a comprehensive context for future applications. Initially, we tested the impact of spectral quality and light intensity on P. tricornutum transformed with an episomal vector (Ptev), harboring the resistance gene Sh ble. Results indicated that Ptev cells accumulated more biomass and overall lipids in spectral quality Red 1 (R1: 34% > 600 nm > 66%) more effectively as compared to Red 2 (R2: 8% > 600 nm > 92%). It was also detected that cell granularity was higher in R1 as compared to R2. Furthermore, by testing two light intensities 65 μmol·m-2·s-1 and 145 μmol·m-2·s-1 light, it was observed that 145 μmol·m-2·s-1 led to an increase in growth trend, total biomass and lipid content. Combining spectral qualities and light intensities, we show that the lipid accumulation raised by 2.8-fold. Studying the light intensity and spectral quality allowed us to optimize the light conditions to R1 spectral quality and light intensity 145 μmol·m-2·s-1. These initial results showed that red light R1 at 145 μmol·m-2·s-1 was the best condition for biomass and total lipids accumulation in Ptev cells. Next, we further combined these two-light optimizations with a third light characteristics, i.e. light shift, where the cultures were shifted during the early stationary phase to a different light environment. We studied Red light shift (Rs) to investigate how light condition variations impacted P. tricornutum transconjugants Ptev and with an episomal vector containing the reporter gene YFP (PtYFP). We observed that Rs induced growth and fatty acid eicosapentaenoic acid (EPA) in Ptev as compared to PtYFP. Altogether, the study shows that red light shift of R1 at 145 μmol·m-2·s-1 promoted biomass and total lipids accumulation in Ptev and PtYFP cells. The study provides a comprehensive approach to using different light characteristics with the aim to optimize growth and lipids, as well as to fatty acid production.

硝酸钠浓度对三角褐指藻(Phaeodactylum tricornutum)MACC/B226生长及脂肪酸组成的影响

在温度为22±1℃ ,盐度为28,硝酸钠浓度分别为75,375,750,1125,1500,1875mg/L的条件下 ,用F/2培养基对青岛海洋大学微藻种质库保存的三角褐指藻(Phaeodactylumtricor-nutum)MACC/B226进行培养 ,测定了生长及脂肪酸组成。实验结果表明 ,在硝酸钠浓度为1125mg/L时 ,三角褐指藻相对生长率最高。在75～375mg/L之间二十碳五稀酸 (EPA)含量随着硝酸钠浓度的增加而增加 ,在375～1875mg/L之间EPA含量变化不大 ,在1875mg/L时达到最高值 (占总脂肪酸的12.6% )。

三角褐指藻(Phaeodactylum tricornutum)形态及其变异现象的研究

分别对青岛、浙江、上海和厦门四地的三角褐指藻藻种及单个细胞克隆后多个藻株的形态及其变异现象进行了比较研究。青岛、上海藻种短期培养后 ,培养液细胞基本由梭形细胞组成 ;浙江和厦门藻种则基本由三出放射形细胞组成。正常培养液中卵形细胞比例均在 0 .1%以下。特定条件下 ,梭形和三出放射形细胞均能产生卵形细胞 ,卵形细胞也能发育成梭形或三出放射形细胞 ;三出放射形细胞可能经“突变”或“定向变异”转变成梭形细胞 ,而梭形细胞培养液中没有出现三出放射形细胞。培养液比重、温度及光照条件的改变短期内对细胞形态类型的转变没有明显影响 ;淡水和低温 ( 4℃～ 8℃ )的长期胁迫能使梭形和三出放射形藻株发生高比例的卵形细胞。

A comparative analysis of fatty acid composition and fucoxanthin content in six Phaeodactylum tricornutum strains from diff erent origins

Phaeodactylum tricornutum is a potential livestock for the combined production of eicosapentaenoic acid(EPA) and fucoxanthin. In this study, six marine diatom strains identified as P. tricornutum were cultured and their total lipid, fatty acid composition and major photosynthetic pigments determined. It was found that the cell dry weight concentration and mean growth rate ranged between 0.24–0.36 g/L and 0.31–0.33/d, respectively. Among the strains, SCSIO771 presented the highest total lipid content, followed by SCSIO828, and the prominent fatty acids in all strains were C16:0, C16:1, C18:1, and C20:5(EPA). Polyunsaturated fatty acids, including C16:2, C18:2, and EPA, comprised a significant proportion of the total fatty acids. EPA was markedly high in all strains, with the highest in SCSIO828 at 25.65% of total fatty acids. Fucoxanthin was the most abundant pigment in all strains, with the highest in SCSIO828 as well, at 5.50 mg/g. The collective results suggested that strain SCSIO828 could be considered a good candidate for the concurrent production of EPA and fucoxanthin.

Variation of bacterial community associated with Phaeodactylum tricornutum in response to different inorganic nitrogen concentrations

Specific bacterial communities interact with phytoplankton in laboratory algal cultures. These communities influence phytoplankton physiology and metabolism by transforming and exchanging phytoplankton-derived organic matter. Functional bacterial groups may participate in various critical nutrients fluxes within these associations, including nitrogen(N) metabolism. However, it is unclear how bacterial communities and the associated algae respond to changes of phycosphere N conditions. This response may have far-reaching implications for global nutrient cycling, algal bloom formation, and ecosystem function. Here, we identified changes in the bacterial communities associated with Phaeodactylum tricornutum when co-cultured with different forms and concentrations of N based on the Illumina HiSeq sequencing of 16 S rRNA amplicons.Phylogenetic analysis identified Proteobacteria and Bacteroidetes as the dominant phyla, accounting for 99.5% of all sequences. Importantly, bacterial abundance and community structure were more affected by algal abundance than by the form or concentration of inorganic N. The relative abundance of three gammaproteobacterial genera(Marinobacter, Algiphilus and Methylophaga) markedly increased in N-deficient cultures. Thus, some bacterial groups may play a role in the regulation of N metabolism when co-cultured with P.tricornutum.

Nuclear Transition Between the Conjunction Cells of Phaeodactylum tricornutum Bohlin (Bacillariophyta)

Phaeodactylum tricornutum is one of the important marine diatoms for oceanic primary production. Its reproduction has profound significance in the life cycle; however, the nuclear behavior during its sexual reproduction was not clear. In this study, we observed the nuclear transition and determined its correlation with cell conjunction. It was found that two cells jointed at their apices first and swung and aligned each other immediately, and nucleus from one cell was able to transfer into another one during cell conjugation. The cell pairs conjugated for nuclear transition were different from those formed in mitosis in hypovalve thickness and cellular arrangement. Our findings proved the existence of sexual reproduction in P. tricornutum.

Metabolomic and proteomic responses of Phaeodactylum tricornutum to hypoxia

Diatoms are important contributors to global net primary productivity,and play a crucial role in the biogeochemical cycles of carbon,phosphorus,nitrogen,iron,and silicon.Currently in some regions in the ocean,there’s a trend that carbon content is high while oxygen concentration is low,and the underlying mechanisms of diatoms’response to low oxygen environments are worth investigating.Phaeodactylum tricornutum is a model diatom whose genome has been sequenced;it provides a universal molecular toolbox and a stable transgenic expression system.Therefore,the study of the responses of P.tricornutum to low oxygen has not only fundamental research significance but also important ecologic al significance.In this study,growth rates were determined and proteomic analysis and metabolomic analysis were performed to examine P.tricornutum responses under different oxygen concentrations(2%oxygen concentration for hypoxic condition and 21%oxygen concentration for the normal condition(sterilized air)).Results show that the hypoxic environment inhibited the growth of P.tricornutum.In the hypoxic conditions,P.tricornutum could reset its metabolism pathways,including enhancement in lipid utilization,replenishment of tricarboxylic acid(TCA)cycle through the glyoxylic acid cycle,and down-regulation of photorespiration to reduce energy waste.Additionally,the stress resistance mechanism was activated to facilitate the adaptation to low oxygen conditions.This study helps to reveal the different metabolic changes to hypoxia of diatom from that of higher plants,which might be ascribed to their different habitats and needs further exploration in the future.

Association of triacylglyceride content and transcript abundance of genes involving in lipid synthesis of nitrogen deficient Phaeodactylum tricornutum

Phaeodactylum tricornutum is a diatom that is rich in lipids. Recently, it has received much attention as a feedstock for biodiesel production. Nitrogen deficiency is widely known to increase the content of neutral lipids （mainly triacylglycerides, or TAGs） of microalgae, including P. tricornutum, but the mechanism is unclear. In this study, we deciphered the correlations between TAG content and nine key enzymatic genes involved in lipid synthesis in P. tricornuturn. After being cultured under nitrogen-free conditions for 0, 4, 24, 48, 72, 120, and 168 h, the TAG contents ofP. tricornutum cells were assayed and the transcript abundances of the target genes were monitored by quantitative real-time PCR. The results show that the abundances of four target gene transcripts （LACS3, G3PDH2, G3PDH3, and G3PDH5） were positively correlated with TAG content, indicating that these genes may be involved in TAG synthesis in P. tricornutum. The findings improve our understanding of the metabolic network and regulation of lipid synthesis and will guide the future genetic improvement of the TAG content ofP. tricornutum.

三角褐指藻(Phaeodactylum tricornutum)通用转化载体的构建

三角褐指藻(Phaeodactylum tricornutum)是开展微藻生物柴油研究的理想材料。克隆了内源fcp基因簇的多个调控序列(启动子、终止子),构建了包括fcpB启动子-bar基因-fcpA终止子、以及fcpA启动子-多克隆位点(MCS)-fcpA终止子两个表达盒的通用转化载体pfcpA-MCS/fcpB-Bar,其特征是以bar基因作为选择标记,MCS区方便插入一至多个目的基因。新载体可用于三角褐指藻的重组蛋白表达、或油脂代谢相关基因的功能验证和代谢调控研究。

纳米二氧化钛(nTiO2)对三角褐指藻(Phaeodactylum tricornutum)光合系统的影响

随着人工纳米材料(MNMs)的大规模使用,其环境暴露风险也随之升高。MNMs中纳米二氧化钛(nTiO2)产量最大,应用广泛,其环境与健康风险备受关注。已有大量研究关注短期暴露下nTiO2的毒性效应,但对暴露过程中浮游植物的应激机制仍缺乏认识;以往的研究发现nTiO2干扰浮游植物叶绿体的正常光合作用,但与浮游植物光合作用相关的基因表达在nTiO2胁迫下如何变化尚不清楚。该研究通过分析浮游植物光合系统相关指标如叶绿素a、Fv/Fm、光合作用基因的表达等,试图探究不同浓度nTiO2(0、5、10、20、50、100 mg·L-1)对三角褐指藻(Phaeodactylum tricornutum)的毒性效应及其潜在机制。叶绿素a的测定结果表明nTiO2对三角褐指藻的抑制效应较微弱,暴露于10 mg·L^-1 nTiO248 h后,三角褐指藻叶绿素a含量约为对照组的76.35%;暴露120 h后恢复至对照组的94%。此外,Fv/Fm在暴露48 h前后具有类似的趋势,暴露组在48 h前Fv/Fm显著低于对照(P<0.05),但48 h后并没有明显变化。这些结果表明nTiO2对三角褐指藻的毒性效应随时间逐渐减弱,推测三角褐指藻可能对nTiO2存在一定的抗性。进一步的研究发现,与光合作用相关基因rbcS和LcyB在三角褐指藻暴露48 h后显著下调,但处理120 h后,显著高于对照组。这一变化可能是叶绿素a含量先下降后恢复的分子机制。该研究结果为探讨nTiO2对海洋微藻的光合毒性效应以及海洋微藻在nTiO2暴露下的响应机制提供基础。

紫外辐射(UVB)胁迫下南极硅藻Phaeodactylumtricornutum ICE-H的生理生化与抗氧化活性响应

对分离自南极海冰的南极硅藻Phaeodactylum tricornutum ICE-H实施一定强度的中波紫外线(UVB)(70μw/cm2)辐射(0~7 d),研究了其生理生化指标的变化情况,并了解了UVB辐射对其生长及生物组成的影响。结果表明:(1)在UVB胁迫下,该南极硅藻生长速率下降,干重减少,总蛋白含量降低,总脂含量增加;(2)总单不饱和脂肪酸(MUFA)含量降低,总多不饱和脂肪酸(PUFA)含量升高;(3)叶绿素a、叶绿素b及总叶绿素含量均降低;(4)抗氧化系统作用相应明显,活性氧自由基(ROS)生成速率增加,丙二醛(MDA)大量产生及总超氧化物歧化酶(SOD)大量累积。本研究为进一步认识南极硅藻Phaeodactylum tricornutum ICE-H应对UVB辐射的机理以及南极生态系统对UV-B辐射响应提供启示。

三角褐指藻(Phaeodactylum tricornutum)油脂富集培养的研究

探讨了营养盐铁、硅及植物激素脱落酸(ABA)单因子对三角褐指藻(Phaeodactylumtricornutum)的生长、油脂含量(%干重)及油脂产量的影响.采用光密度值OD_(450)评价微藻的生长状况,以溶剂浸提法提取油脂.结果表明:(1)铁处理组中,铁浓度在0～46.57umol/L范围内时,藻的生长速率随铁浓度提高而增大;铁浓度为11.64μmol/L时,油脂含量达30%,高于其它铁浓度培养;当铁浓度为11.64μmol/L时,油脂产量最高——是无铁培养的2.8倍;(2)硅处理组中,低含量硅盐(4.6μmol/L)不仅促进了藻的生长而且提高了油脂含量,油脂产量比高含量硅盐(42.6μmol/L)培养提高了40%;(3)ABA处理组中,1 mg/L ABA不仅促进了藻的生长而且提高了油脂含量,油脂产量比对照提高了50%;5 mg/L ABA虽提高了油脂含量但却抑制了藻的生长,油脂产量和对照相当;15 mg/L ABA抑制了藻的生长、降低了油脂含量.用气相色谱分析微藻的脂肪酸组成,结果显示:1 mg/L ABA明显影响了三角褐指藻的脂肪酸组成,以高产量油脂(4.6μmol/L硅盐、1 mg/L ABA培养)为原料制备出的生物柴油的质量将会提高.

Hormesis-like growth and photosynthetic physiology of marine diatom Phaeodactylum tricornutum Bohlin exposed to polystyrene microplastics

The effects of pristine polystyrene microplastics(pMPs)without any pretreatment at different concentrations(0,10,20,50,and 100 mg/L)on Phaeodactylum tricornutum Bohlin at two initial algae densities(105 and 106 cells/mL)were assessed in this study.Hormesis-like effects were found when microalgae grew with pMPs.The results showed that pMPs inhibited microalgae growth under a high concentration of microplastics tolerated by individual algal cell(low initial algae density)(up to-80.189.71%)but promoted growth when the situation was opposite(up to 15.273.66%).The contents of photosynthetic pigments including chlorophyll a,chlorophyll c and carotenoids showed resistance to pMPs stress under a low initial algae density and increased with time,but the opposite was true under a high initial algae density.Compared with the low initial algae density group,Qp received less inhibition,and NPQ(heat dissipation)also decreased under the high initial algae density.Under the low initial algae density,OJIP parameters such as Sm,N,Area,Pi Abs,ѱo,φEo,TRo/RC and ETo/RC were more perturbed initially and returned to the levels of the control group(without pMPs)over time,but they remained stable throughout the experiment at high initial algae density.These results show that microplastics in the marine environment may have different toxic effects on P.tricornutum at different growth stages,which is of great significance for understanding the impact of microplastics on marine microalgae and aquatic ecosystems.

Effects of Glycerol on the Fluorescence Spectra and Chloroplast Ultrastructure of Phaeodactylum tricornutum(Bacillariophyta)

Responses of the photosynthetic activity of Phaeodactylum tricornutum （Bacillariophyta） to organic carbon glycerol were investigated. The growth rate, photosynthetic pigments, 77 K fluorescence spectra, and chloroplast ultrastructure of P. tricornutum were examined under photoautotrophic, mixotrophic, and photoheterotrophic conditions. The results showed that the specific growth rate was the fastest under mixotrophic conditions. The cell photosynthetic pigment content and values of Chl a/Chl c were reduced under mixotrophic and photoheterotrophic conditions. The value of carotenoid/Chl a was enhanced under mixotrophic conditions, but was decreased under photoheterotrophic conditions. In comparison with photoautotrophic conditions, the fluorescence emission peaks and fluorescence excitation peaks were not shifted. The relative fluorescence of photosystem （PS） Ⅰ and PS Ⅱ and the values of F685/F710 and F685/F738 were decreased. Chloroplast thylakoid pairs were less packed under mixotrophic and photoheterotrophic conditions. There was a strong correlation between degree of chloroplast thylakoid packing and the excitation energy kept in PS Ⅱ. These results suggested that the PS Ⅱ activity was reduced by glycerol under mixotrophic conditions, thereby leading to repression of the photosynthetic activity.

Bioaccumulation and transformation of cadmium by Phaeodactylum tricornutum

In this paper,we report the bioaccumulation and transformation of cadmium (Cd) by Phaeodactylum tricornutum in the presence of ethylenediamine tetra acetic acid (EDTA) and cysteine (Cys). Both EDTA and Cys can alleviate the toxicity of Cd to P. tricornutum. Short term intracellular uptake and extracellular adsorption experiments using ICP-MS indicated that the amounts of Cd accumulated on the cell surface of P. tricornutum and inside the cell decreased along with the increase of EDTA concentration,which conformed to the prediction of the Free Ion Activity Model (FIAM). However,extracellular adsorption of Cd increased at first and then decreased along with the increase in the concentration of Cys,while intracellular uptake increased under Cys concentrations from the blank value to 4.45 μmol/L,and then tended to remain at the same level when the Cys concentration was greater than 4.45 μmol/L,and this deviated remarkably from the FIAM. The interactions of Cd with _Si_OH,_C_OH and NH2(CO) _OH on the cell wall were confirmed using FT-IR and XPS studies. The results obtained using HPLC of the phytochelatins (PCs) produced by P. tricornutum under CdCl2,Cd_EDTA and Cd_Cys stress suggested that the main reason for the different effects of EDTA and Cys on the bioaccumulation and transformation of Cd by P. tricornutum was that Cys is not only a complexing ligand to Cd,as is EDTA,but also it is a precursor of the intracellular synthesizing PCs participating in the cellular defense mechanism against Cd. Furthermore,the discovery of in vivo PCs and oxidized_PCs as well as Cd-PC2 in P. tricornutum using ESI-IT-MS provided the evidence for deactivation of Cd by the PCs,reducing Cd-toxicity to P. tricornutum.

Identification and bioinformatics analysis of pseudogenes from whole genome sequence of Phaeodactylum tricornutum

Pseudogenes share sequence similarities with functional genes,but in general they have lost their protein-coding ability.The identification of pseudogenes is a very important step in genome annotation.Phaeodactylum tricornutum is a marine diatom that is rich in polyunsaturated fatty acids(PUFAs).The genome of P.tricornutum has been completely sequenced.To identify pseudogenes in P.tricornutum,we developed a pipeline to discover and characterize pseudogenes.We identified a total of 1654 'true' processed pseudogenes,714 duplicated pseudogenes and 4729 pseudogene fragments.The results of the bioinformatics analysis indicated that the genome sequence of P.tricornutum contained many pseudogenes and pseudogene fragments.

尿苷二磷酸葡萄糖促进三角褐指藻岩藻黄素积累的研究

岩藻黄素(Fucoxanthin)是自然界中丰富的类胡萝卜素,为提高微藻中岩藻黄素的含量,本实验主要通过叶绿素荧光参数法、高效液相色谱法等探究了外源添加不同浓度的尿苷二磷酸葡萄糖(UDPG)对三角褐指藻光合作用能力及岩藻黄素含量的影响。研究表明,150μmol/L UDPG显著提高了三角褐指藻的光合作用能力,促进了三角褐指藻中岩藻黄素积累,其含量达到(9.57±0.81)mg/g,比对照组提高了161.76%。此外,硅甲藻黄素、硅藻黄素、β-胡萝卜素、紫黄质、叶绿素a和叶绿素c 2的含量分别比对照组提高了84.31%、79.73%、164.74%、123.04%、358.35%和2260.09%。研究结果表明,外源添加150μmol/L UDPG可显著促进三角褐指藻积累岩藻黄素。

New Insights in the Biodegradability and the Ecotoxicological Effects of Solar Products Containing Mineral and Chemical UV-Filters on Marine Zoo- and Phytoplanktons: An in silico and in vitro Study

Background: Cosmetic formulations, and particularly solar products which contain mineral and chemical UV-filters, are often suspected of causing harmful effects on marine fauna and flora. After the publication of our work in 2019 concerning the ecotoxicological effects of such formulations on corals (Seriatopora hystrix), we here provide some new information about the biodegradability and the ecotoxicological effects of these products on marine zoo- and phytoplankton. Therefore, we choose to realize in silico and in vitro studies of the biodegradability of several solar products but also to evaluate the ecotoxicological effects of these products on one phytoplankton, i.e. Phaeodactylum tricornutum, and one zooplankton, i.e. Acartia tonsa, of a great importance for sea species survival (notably as sources of food). Materials and methods: Two different approaches were used to study the biodegradability of the tested products: One in silico method and an in vitro one. 2 solar products were involved in the in silico study which consisted in the determination of the degradation factor (DF) of each ingredient of the tested formulas in order to finally obtain their estimated biodegradability percentage. Already available data concerning each ingredient coupled to a computer model developed with one of our partners were used to achieve this study. The in vitro study involved 8 formulas containing UV-filters and was led by following the OECD 301 F guidelines. Ecotoxicological studies of 7 of the formulas containing UV-filters were for their part realized by following the ISO 10253 guidelines for the experiments led with Phaeodactylum tricornutum, and the ISO 14669 guidelines for the experiments led with Acartia tonsa. In these studies, the effect of each tested product on crustaceans’ mortality and algal growth inhibition was assessed. Results: The in silico study predicted that formulas containing chemical UV-filters display a high biodegradability (superior to the threshold value of 60% given by the OECD 301 F guidelines). In the in vitro part of our work, the 8 tested formulas showed a biodegradability slightly inferior to the one predicted in the in silico experiments. Therefore, in order to evaluate if these calculated biodegradability value could have significant harmful effects on zoo- or phytoplankton, we studied the effect of our products regarding the growth inhibition on Phaeodactylum tricornutum and the mortality on Acartia tonsa. In this last part of the study, all the tested products were classified as “non ecotoxic” following an internal classification based on Part 4 entitled “Environmental Hazards” of Globally Harmonized System of Classification and Labelling of Chemicals (GHS), 9th edition (2021). Conclusions: These results are notably in line with those published by our teams in 2019 on the effects of solar cosmetic products on corals and seem to confirm that formulas containing mineral and chemical UV-filters can be daily used without displaying significant noxious effects on marine fauna and flora. .