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The Tetraselmis chuii microalgae have a potential as an alternative raw material for producing bioethanol, because of its low lignin and high carbohydrate content. The purpose of this research is to study the kinetics of enzymatic hydrolysis of Tetraselmis chuii using Valjamae model. This experiment was carried out with a variety of enzymes (cellulase, xylanase, and cellulase-xylanase mixture, enzyme concentrations (10, 20, and 30% w/w), times (10, 20, 30, and 40 min), and temperatures (40 and 45 °C). The results show that the activation energy of hydrolysis using cellulase-xylanase mixture is 27,253 J/mol, xylanase 116,121J/mol, and cellulose 140,914 J/mol. At 45 °C, the concentration of the cellulase-xylanase mixture increased (10, 20, and 30% w/w), the reaction rate constants (0.028, 0.110, and 0.171 1/min) as well as the fractal exponents (0.4, 0.6, and 0.7). Thus, the glucose production rate is higher, where at 40 minutes produces higher yields (23.5, 25.5, 28.5, and 32.5%). In this study, the constant rate of Tetraselmis chuii hydrolysis using cellulase-xylanase mixture at 45 °C is 0.1714 1/min; higher than the one conducted at 40°C which is 0.1454 1/min. The kinetic parameters of the enzymatic hydrolysis are expected to help in bioreactor design.

The objective of this techno-economic analysis (TEA) was to define the production cost of the microalga Tetraselmis suecica in a 1-ha plant made of “Green Wall Panel-II” (GWP®-II) photobioreactors. The study was based on an energy analysis carried out for a similar plant located in Tuscany (Italy) and considers the steps from inoculum preparation to the wet algal paste. Costs of equipment and materials were obtained from manufacturers and suppliers, while operating costs and output data (e.g. biomass composition and productivity) were collected during several years of trials at the Fotosintetica & Microbiologica S.r.l. facilities (Florence, Italy). Other data were obtained from Microalghe Camporosso S.r.l. (Imperia, Italy), where a commercial 1500-m2 GWP®-I plant is in operation and two 250-m2 GWP®-II modules were built and used in the framework of the EU project BIOFAT. This TEA shows that, given a productivity of 36 tonnes per hectare per year, T. suecica biomass can be produced at a cost of €12.4 kg− 1 (dry weight). Using conservative assumptions it was estimated that at the 100-ha scale the cost will be €5.1 kg− 1. Locating the plant in more favorable climatic conditions (e.g. in Tunisia) will allow reaching 54 tonnes per hectare annually and reducing cost to €6.2 kg− 1 at the 1-ha scale and to €3.2 kg− 1 at the 100-ha scale. The major cost factors are labor at 1-ha scale in Tuscany and capital expenses in all the other cases. This TEA confirms that microalgal technologies have high potential not only for high-value, but also for medium- and low-value products, while the production of biofuels, protein, food and feed seems currently out of reach. However, the global scenario of agriculture commodities is rapidly changing and other factors (e.g. sustainability), besides a pure economic evaluation, will assume greater importance in the future.

Integrated multi-trophic aquaculture (IMTA) is a promising direction for the sustainable development of aquaculture. Microalgae have good potential to be integrated with recirculating aquaculture systems because they can use the nitrogen excreted from fish and share the same optimal pH value as in aquaculture. As a byproduct, the microalgae biomass can be used for fish feed or biofuel. However, the recirculating fish-microalgae IMTA system is under constant threat from fish pathogens and phytoplankton-lytic bacteria. Therefore, it is necessary to apply proper disinfectants as prophylaxis or treatment which are effective against these threats, but safe to fish and microalgae. For this purpose, peracetic acid (PAA) is a valid option because it is highly effective against fish pathogens and bacteria at low concentrations and degrades spontaneously to harmless residues. In the present study, we exposed the culture of a marine microalgae Tetraselmis chuii once per day for four days to four PAA products with differing hydrogen peroxide (H 2 O 2 )/PAA proportions at two concentrations (1 and 2 mg L −1 PAA). The H 2 O 2 solutions at equivalent total peroxide (H 2 O 2 + PAA) concentrations were tested in parallel. The results show that the growth and photosynthesis of T. chuii were not affected by three of the PAA products (Wofasteril ® E400, Wofasteril ® E250 and Applichem ® 150) and equivalent H 2 O 2 solutions at both concentrations. In contrast, Wofasteril ® Lspez and an equivalent H 2 O 2 solution at both concentrations caused irreversible culture collapse, photosynthesis dysfunction and irreversible cell damage. In conclusion, PAA products with low proportions of H 2 O 2 are optimal disinfectants for fish-microalgae IMTA systems.

Interactions between algae and associated bacterial communities in the phycosphere depend on many factors such as culture age, nutrient availability, and antibiotic production and greatly influence algal survival and growth. The microbial community associated with the marine microalga Tetraselmis suecica F&M-M33 in a laboratory culture and an outdoor mass culture, set up from the laboratory one, run during a whole year was investigated in different seasons through isolation in pure culture of bacteria, amplified ribosomal DNA restriction analysis (ARDRA) of all the isolates, and terminal restriction fragment length polymorphism (T-RFLP) analysis. The total number of bacterial isolates was 152, which clustered in thirty-six 16S rDNA groups by ARDRA. Sequencing of a representative of each ARDRA group permitted identification of bacterial genera never reported before in association with microalgae in outdoor mass cultures, although most of them were previously found to be associated with the marine environment (e.g., seawater, sea sediments). T-RFLP analysis revealed that spring and autumn bacterial community profiles were closely related, while the bacterial laboratory community was considerably different (less than 50 % similarity) from that associated with the outdoor culture in different seasons. T-RFLP results suggest the presence of a core of bacteria that are closely associated with the alga and of a part of the community which varies seasonally.

We apply Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) for direct characterization of iron-porphyrins in hydrothermal liquefaction (HTL) biocrude oils derived from two algae: Tetraselmis sp. and cyanobacteria. The iron porphyrin compounds are shown to cause catalyst bed plugging during hydroprocessing due to iron deposition. Inductively-coupled plasma optical emission spectrometry (ICP-OES) was utilized for iron quantitation in the plugged catalyst beds formed through hydroprocessing of the two HTL biocrudes and identifies an enrichment of iron in the upper five centimeters of the catalyst bed for Tetraselmis sp. (Fe = 100,728 ppm) and cyanobacteria (Fe = 115,450 ppm). Direct infusion FT-ICR MS analysis of the two HTL biocrudes with optimized instrument conditions facilitates rapid screening and identification of iron porphyrins without prior chromatographic separation. With FT-ICR MS we identify 138 unique iron porphyrin compounds in the two HTL biocrudes that have similar carbon number and double bond equivalent distributions to the metal porphyrins (e.g. Ni and V) reported for petroleum. No iron porphyrins are observed in the cyanobacteria HTL biocrude after hydroprocessing, which indicates that iron porphyrin structures in the HTL biocrude are degraded during hydrotreatment. Hydrodemetallization reactions that occur through hydroprocessing of HTL biocrudes could be responsible for the decomposition of iron porphyrin structures leading to metal deposition in the catalyst bed that result in catalyst deactivation and bed plugging, and must be addressed for effective upgrading of algal HTL biocrudes.

In this study, an alternative approach was proposed where excess seawater would be added only during inoculation (DD) rather than daily addition (FD). Growth and metabolite contents of Tetraselmis sp. weren't affected for daily increase of 2% NaCl salinity. Tetraselmis sp. was then cultured in DD and FD pond. In DD pond, initial culture depth was 23.5 cm and its depth reduced as no water was added; for FD pond, everyday sterilized seawater was added to maintain 20 cm depth. DD pond had higher biomass productivity compared to FD pond, until DD pond was deeper than FD pond; metabolite content and FAME profile of Tetraselmis sp. were also similar in both cultures. Therefore, considering the simplicity in operation, halo tolerant microalgae can be grown in DD pond method. 2016. Scopus

The genus Tetraselmis includes various species that are widely used as food microalgae in aquaculture. However, the mass cultivation of Tetraselmis spp. has been restricted to traditional photoautotrophic culture. Here, we investigated the heterotrophic culture condition for Tetraselmis chuii and assessed growth rate, morphology, and biomass productivity of T. chuii under heterotrophic culture conditions. Protein, polysaccharide, chlorophyll, total lipids, and fatty acid compositions under different initial C/N ratios were also analyzed. Tetraselmis chuii was found to be able to grow using glucose as the sole carbon source under strict heterotrophic conditions. Moreover, T. chuii showed a better heterotrophic growth status in the medium with 10 g L−1 glucose compared to the autotrophic condition. Comparatively high optical density and biomass were obtained at C/N ratios of 16 and 12. The dry weights of T. chuii under C/N ratios of 16 and 12 were 1.37 ± 0.04 and 1.26 ± 0.06 mg mL−1, respectively, significantly higher than those of the autotrophic group. In addition, T. chuii synthesized more polysaccharide under heterotrophic conditions, especially at a C/N ratio of 24. Tetraselmis chuii cultured under C/N ratios of 4 and 8 produced the highest percentages of C16:0 (43.36 %) and C18:1 (47.49 %) fatty acids, and more fatty acids, including C14:0, C18:0, C20:2, and C20:4, were detected in the groups with C/N ratios of 4 and 24. These findings may provide the basis for the mass culture of heterotrophic T. chuii by highlighting sources of plentiful nutrient substances, especially polysaccharides, for aquaculture.

Microalgae are a promising source of lipids for biodiesel production, which has the potential to replace fossil fuels without affecting the supply of foods and crop products. From the production of biodiesel, a solid waste known as lipid-extracted microalgae (LEM) is generated as a byproduct, and it is considered a rich source of antioxidant compounds, mainly polyphenols. In this study, optimization of the process variables of acid-catalyzed hot-water extraction was performed at low temperature in order to increase the production of polyphenols from LEM (Tetraselmis KCTC 12236BP). A statistically based method was used to optimize key variables, including extraction temperature, time, and sulfuric acid concentration. The results indicated that all process variables had significant effects on the extraction of polyphenols (p < 0.05). For instance, polyphenol levels increased in accordance with the increase of the three variables. The most economical optimal conditions were 100°C, 46.8 min, and 0.32 N H2SO4, under which polyphenol yield was 8.04 mg gallic acid equivalent (GAE)/g dry matter (DM), 5.2-fold higher than that from hot-water extraction without optimization.

Biochemical components obtained by microalgal biomass can be induced by specific wavelengths and processed to high value food/feed supplements or pharma- and nutraceuticals. Two biotechnologically relevant microalgae, Nannochloropsis oculata and Tetraselmis chuii, were exposed to non-tailored LEDs light sources emitting either mono- or multichromatic light with low red but significant blue (

SUMMARY To perform effective measurement of the protein contents, it is necessary to apply the most suitable extraction technique. We compared protein extraction techniques for two microalgal species with entirely different cell wall structures, such as diatom Thalassiosira weissflogii and green flagellate Tetraselmis chuii, using mechanical, physical, and chemical extraction methods. Our results showed that in Th. weissflogii, the control treatment without extraction and mechanical disruption using ultrasonication was sufficient to disrupt its brittle cell wall, resulting in the protein yield of 19.03 and 19.46% of dry weight (DW), respectively. In case of Te. chuii, the chemical extraction using 6% trichloroacetic acid at 95°C was the most suitable extraction method, resulting in the protein yield of 23.78% of DW. Therefore, the most suitable extraction technique must be individually selected for each species depending on their cell wall properties.

Mass microalgal culture plays an irreplaceable role in aquaculture, but microalgal productivity is restricted by traditional autotrophic culture conditions. In the present study, a Tetraselmis chuii strain belonging to the phylum Chlorophyta was isolated from south Yellow Sea. The growth rate and biomass productivity of this strain was higher under mixotrophic conditions with different carbon:nitrogen (C:N) ratios than those under autotrophic conditions. When the C:N ratio was 16, the optical density and biomass productivity were 3.7- and 5-fold higher than their corresponding values under autotrophic culture conditions, respectively. Moreover, T. chuii synthesized more polysaccharides and total lipids under mixotrophic conditions. In addition, T. chuii cultured under mixotrophic conditions synthesized more types of fatty acids than autotrophic culture conditions. At a C:N ratio of 16, the percentage of C16:0 and C18:1 reached 30.08% and 24.65% of the total fatty acid (TFA) content, respectively. These findings may provide a basis for large-scale mixotrophic culture of T. chuii, as a potential bait-microalga.

We report the results of survival and growth in size and dry mass of spat of the Caribbean pearl oyster Pinctada imbricata cultivated under outdoor (field culture) and indoor (Laboratory) conditions. Field group fed on environmental seston. Laboratory groups were fed with mono, binary and ternary mixtures of three cultivated algae: Isochrysis galbana (Ig), Tetraselmis chuii (Ig) and the Chaetoceros sp. (Ch-A, isolated from north-eastern Venezuela). After 30 days of trial, fatty acid profiles of spat were determined along with growth in length and height shell, adductor muscle and soft tissue dry mass. During the field grow-out phase (field culture), samplings were performed at days 1, 15 and 30 to measure environmental variables of phytoplankton biomass (chlorophyll a), dissolved oxygen, seston, temperature and salinity. A significant increase in size and soft tissue mass occurred in spat fed the diets including the tropical diatom (Chaetoceros sp.). In contrast, monoalgal diets of Tc and Ig yielded no significant differences in size and mass of spat, compared with the field culture. These results suggest that nutritional requirements of cultivated spat for specific fatty acids of physiological importance for marine bivalves, such as: 16:0, 16:1n-7, 18:2n-6, 20:4n-6, 18:3n-3 and 20:5n-3, were satisfied from microalgal diets with Ch-A, alone or in combination, compared with spat fed from the field culture.

Culturing microalgae using commercial media is expensive. Proliferation of aquaculture is generating high amount of wastewater containing nitrogen and phosphorus and this could be a source of nutrient for cultivating microalgae thereby reducing the production costs. This study compared the growth, productivity, and proximate composition of Chaetoceros calcitrans, Nannochloris maculate, and Tetraselmis chuii cultured in aquaculture wastewater and Conway medium. Results indicated that selected microalgae cultivated in wastewater and Conway medium did not show any significant differences (p > 0.05) in terms of cell density, optical density, and biomass. Further, volumetric and areal productivity showed similar trend for all the three species. But lipid productivity (LP) in N. maculate was significantly higher (p 0.05) for C. calcitrans and T. chuii in terms of LP when cultivated in the...

Pemantauan pertumbuhan mikroalga ( Tetraselmis sp. dan Nannochloropsis sp.) merupakan salah satu faktor penting dalam budidaya ikan dan udang. Tujuan penelitian ini adalah untuk mengetahui karakteristik pertumbuhan Tetraselmis sp. dan Nannochloropsis sp. dengan mengukur kerapatan optik menggunakan metode spektrofotometri. Penyerapan 600 nm digunakan untuk kedua spesies. Hasil penelitian menunjukkan bahwa pertumbuhan maksimum dicapai pada hari ke 6 untuk kedua mikroalga dengan nilai OD masing-masing 1,734 ± 0,013 dan 1,329 ± 0,002 untuk Tetraselmis sp. dan Nannochloropsis sp.. Tetraselmis sp. memiliki tingkat pertumbuhan maksimum 0,74/hari dan waktu penggandaan 22,43 jam sedangkan Nannochloropsis sp. memiliki tingkat pertumbuhan maksimum 0,86/hari dan waktu penggandaan 19,25 jam. Penelitian ini menunjukkan bahwa absorbansi 600 nm cocok untuk mengetahui pertumbuhan mikroalga hijau dan metode spektrofotometri yang dapat digunakan secara efisien untuk memantau pertumbuhan mikroalga.

Biocrude was produced from Tetraselmis sp. - a marine alga and Arthrospira platensis - a fresh water alga using hydrothermal liquefaction (HTL) process. Considering the constraints in cultivating algae for replacing 100% petrocrude, this study evaluated the option of blending and co-processing algal biocrude with petrocrude. Biocrudes obtained from algal strains cultivated in fresh water and sea water were blended with petrocrude at 10% concentration and the characteristics were studied using FT-IR and CNS SIMDIST. True Boiling Point (TBP) distillation was carried out to assess yields and properties of distillates of blended biocrudes. Biocrudes obtained from both algae were light crudes and the blended crudes recorded distillate yields of 76-77 wt%. The yield of light naphtha fraction of biocrude blends was 29-30%; whereas the yield of diesel fraction was about 18%. This study proposes blending and co-processing of algal biocrude with petrocrude to produce drop-in biofuels.

Culturing microalgae in the ocean has potentials that may reduce the production cost and provide an option for an economic biofuel production from microalgae. The ocean holds great potentials for mass microalgal cultivation with its high specific heat, mixing energy from waves, and large cultivable area. Suitable photobioreactors (PBRs) that are capable of integrating marine energy into the culture systems need to be developed for the successful ocean cultivation. In this study, prototype floating PBRs were designed and constructed using transparent low-density polyethylene film for microalgal culture in the ocean. To improve the mixing efficiency, various types of internal partitions were introduced within PBRs. Three different types of internal partitions were evaluated for their effects on the mixing efficiency in terms of mass transfer (k(L)a) and mixing time in the PBRs. The partition type with the best mixing efficiency was selected, and the number of partitions was varied from one to three for investigation of its effect on mixing efficiency. When the number of partitions is increased, mass transfer increased in proportion to the number of partitions. However, mixing time was not directly related to the number of partitions. When a green microalga, Tetraselmis sp. was cultivated using PBRs with the selected partition under semi-continuous mode in the ocean, biomass and fatty acid productivities in the PBRs were increased by up to 50 % and 44% at high initial cell density, respectively, compared to non-partitioned ones. The results of internally partitioned PBRs demonstrated potentials for culturing microalgae by efficiently utilizing ocean wave energy into culture mixing in the ocean.

Demand for long chain ω-3 fatty acids from non-fish source for vegetarians has increased recently. Marine microalgae are the primary producers of EPA/DHA and promising alternatives for fish oil. Tropical areas have abundant sunlight throughout the year for microalgal cultivation but this practice can be hindered by high temperature. Discovery of heat-tolerant marine microalgae that can synthesize EPA/DHA will solve these problems. A new species of microalga was isolated from a high temperature lagoon and identified as Tetraselmis sp. DS3. These cells could grow at 40 °C, the highest temperature for marine microalgal growth ever reported. Its ω-3 fatty acids and EPA accounted for 33 and 10% of total lipids, respectively, grown in nitrogen-depleted conditions. These cells also accumulated more than 5% β-carotene and 0.48% lutein in biomass. This new microalga can be cultivated for long chain ω-3 fatty acids and lutein production in the tropical areas.

The accumulation of atmospheric CO2, primarily due to combustion of fossil fuels, has been implicated in potential global climate change. The high rate of CO2 bioremediation by microalgae has emerged as a favourable method for reducing coal-fired power plant emissions. However, coal-fired power station flue gas contains other chemicals such as SOx which can inhibit microalgal growth. In the current study, the effect of untreated flue gas as a source of inorganic carbon on the growth of Tetraselmis in a 1000 L industrial-scale split-cylinder internal-loop airlift photobioreactor was examined. The culture medium was recycled after each harvest. Tetraselmis suecica grew very well in this airlift photobioreactor during the 7-month experiment using recycled medium from an electroflocculation harvesting unit. Increased medium SO4 2− concentration as high as 870 mg SO4 2− L−1 due to flue gas addition and media recycling had no negative effect on the overall growth and productivity of this alga. The potential organic biomass productivity and carbon sequestration using an industrial-scale airlift PBR at International Power Hazelwood, Gippsland, Victoria, Australia, are 178.9 ± 30 mg L−1 day−1 and 89.15 ± 20 mg ‘C’ L−1 day−1, respectively. This study clearly indicates the potential of growing Tetraselmis on untreated flue gas and using recycled medium for the purpose of biofuel and CO2 bioremediation.

The prasinophytes (early diverging Chlorophyta), consisting of simple unicellular green algae, occupy a critical position at the base of the green algal tree of life, with some of its representatives viewed as the cell form most similar to the first green alga, the 'ancestral green flagellate'. Relatively large-celled unicellular eukaryotic phytoflagellates (such as Tetraselmis and Scherffelia), traditionally placed in Prasinophyceae but now considered as members of Chlorodendrophyceae (core Chlorophyta), have retained some primitive characteristics of prasinophytes. These organisms share several ultrastructural features with the other core chlorophytes (Trebouxiophyceae, Ulvophyceae and Chlorophyceae). However, the role of Chlorodendrophycean algae as the evolutionary link between cellular individuality and cellular cooperation has been largely unstudied. Here, we show that clonal populations of a unicellular chlorophyte, Tetraselmis indica, consist of morphologically and ultrastructurally variant cells which arise through asymmetric cell division. These cells also differ in their physiological properties. The structural and physiological differences in the clonal cell population correlate to a certain extent with the longevity and function of cells.

Harvesting of oleaginous marine microalgae by dewatering is an important step for cost-effective algal biomass feedstock production. This paper reports separation of marine microalgae (Tetraselmis sp. M8) from aqueous medium by froth flotation using various collectors (surfactants) with equal carbon chain length, such as dodecyl pyridinium chloride (DPC), N-dodecylpropane-1,3-diamine hydrochloride (DN2), dodecyl amine hydrochloride (DAH), and sodium dodecyl sulphate (SDS), at different pHs. Algal hydrophobicity, froth stability, and surfactant precipitation were characterised. The laboratory-scale mechanical flotation tests showed that at natural pH 9.5 and a lower pH, DPC outperformed DAH, DN2 and SDS in separating Tetraselmis sp. M8 from seawater. DPC was capable of rendering the microalgae hydrophobic, producing metastable froth, and dissolving readily in water, which are all desirable features of a collector for flotation separation of microalgae from water. Use of DPC at 15 ppm in pilot-scale Jameson cell flotation tests for M8 after outdoor cultivation led to a 23-fold increase in algal concentration with over 99% algal recovery. (C) 2015 Elsevier B.V. All rights reserved.

As the accumulation of microplastics continues to rise in the marine environment, more knowledge on their potential toxic effects on marine organisms is needed to assess their risks to environmental and human health. Thus, the goal of the present study was to investigate the effects of fluorescent red polyethylene plastic micro-spheres 1–5 μm diameter (used as microplastic model and hereafter indicated as MP), alone and in mixture with copper, on the population growth of the marine microalgae Tetraselmis chuii . Two null hypotheses were tested: (H 01 ) Exposure to MP concentrations in ppb range does not affect the average specific growth rate of T. chuii ; (H 02 ) MP do not interact with the toxicity of copper to T. chuii . In laboratory bioassays, T. chuii cultures were exposed for 96 h to MP concentrations ranging from 0.046 to 1.472 mg/l), concentrations of copper alone ranging from 0.02 to 0.64 mg/l, and the same concentrations of copper in the presence of 0.184 mg/l of MP in test media. No significant effects of MP on T. chuii population growth were found (p > 0.05), leading to the acceptance of H 01 . Copper alone significantly decreased the population growth of T. chuii with EC 10 , EC 20 and EC 50 of 0.009, 0.023 and 0.139 mg/l, respectively. The corresponding values in the presence of MP were 0.012, 0.029 and 0.145 mg/l, respectively. Moreover, the study found no significant differences between the toxicity curves of copper in the presence and absence of MP (p > 0.05), leading to the acceptance of H 02 . Despite these findings, because microplastics are known to adsorb and accumulate copper, aged pellets more than virgin ones, and the toxicity of smaller particles may be higher, further studies on the combined effects of copper and microplastics on microalgae should be performed, especially under long-term exposures to nano-sized aged microplastics.

One of larvae feed can be used is Brachionus plicatilis but necessary an enrichment for review adding nutritional values of the Brachionus plicatilis . Some phytoplankton frequently used type food by Brachionus plicatilis between lay Tetraselmis sp., Skeletonema costatum , Chlorella sp., Dunaliella salina and Spirulina sp. (Isnansetyo And Kurniastuty, 1995). In this time, many parlors seed microalgae replace with yeast bread, beside that yeast bread serves as a probiotic too (Winasuria, 1993). This study aims to determine the effect feeding review form a combination of yeast bread and Chlorella sp. against population growth and protein content of Brachionus plicatilis . The research method used is an experimental method with completely randomized design as design of Experiments. The treatment used is a combination of yeast and Chlorella sp. with different period, that was treatment A ( Chlorella sp. 100%), treatment B ( Chlorella sp. 25% and 75% baker's yeast), treatment C ( Chlorella sp. 50% and 50 % of baker's yeast), treatment D ( Chlorella sp. 75% and 25% baker's yeast), each treatment was repeated 5 times. The main parameter observed is population growth, growth rate and protein content. The supporting parameters observed parameter is water quality. Data analysis using variant analysis (ANOVA) and to review the best treatment, Duncan's Multiple Range Test performed. Results Provision combination of baker's yeast and Chlorella sp. with term certain showed significant differences (p

Biofuel production particularly biodiesel has been a subject of investigation worldwide in order to envisage an ecofriendly, renewable source of fuel. Microalgae are one of the key organisms to be utilized in biodiesel production. In the present study, Tetraselmis sp., marine microalgae was investigated for its biodiesel production using the two-stage process optimization method. The first stage consisted of nutrient supplementation with optimization of media (dilution of F/2 media with simulated dairy wastewater) while in second stage, stress factors (nutrient starvation, salinity, pH) were employed with the optimization of factors using response surface methodology. Tetraselmis sp. was grown on different percentage of dairy wastewater and 75% dilution served as better media for growth. The experimental results highlighted that the interaction of nutrient starvation along with salinity was important (p

Microalgae feed production is a major cost in bivalve aquaculture. Its efficiency is increased by scaling it up under automated control of environmental conditions. The initial cost of commercially available systems can be prohibitive. Therefore, a large volume full-scale photobioreactor built of low-cost, readily available materials was developed and tested. A cone-bottom, polyethylene tank was internally illuminated with submersible fluorescent lamps and equipped with a monitoring and control system that measured temperature, pH and optical density of the microalgal culture. Injection of CO2 was automated to maintain pH within a target range. System performance was evaluated by growing four batch cultures of Tetraselmis chuii. Temperature inside the photobioreactor was 29.5 ± 2.38 °C (mean ± SD, range 21−35 °C) and pH was 7.56 ± 0.87 (mean ± SD, range 5.29–8.97). Optimal harvest time was after 300 h (12.5 days) of growth, yielding 1700 L of microalgae at a density of 2500 cells/ μl (1200 cells/ μl/ m2 illuminated surface area). With 24 h illumination, the fluorescent lights, air pump and monitoring/ control device consumed 14.9, 1.9 and 0.1kwh/ day, respectively. Assuming the microalgae are harvested at their optimal density after 12.5 days, each batch would consume 211kwh or 0.124kwh/ liter. The photobioreactor described provides an economical option for growing large amounts of microalgae for aquaculture feed and other purposes.

Wastewater from the leather finishing step in tanneries contains high nutrient loads and toxic compounds, such as dyes, acids, toxic metals among others. To our best knowledge, for the first time, the influence of light period on the treatment of wet-end and finishing leather wastewaters with a microalgae consortium containing mainly Tetraselmis sp. was investigated. In this work, a microalgae consortium present the ability to grow well in this kind of tannery wastewater and was used for reducing nitrogen, phosphorus, ammonium, chemical and biochemical oxygen demands. Additionally, the wastewater presents high turbidity, which has an influence on the penetration of light, during the cultivations. Therefore, the influence of the illumination period was also studied: continuous light (24-light), 12 h light/dark (12-light) and without light (0-light); in addition to the influence of compositions, 50% and 75% of raw wastewater. The maximum concentration of biomass in the wastewater was observed in the 24-light culture: 50R50S (1.40 gL-1) and 75R25S (1.04 gL-1), with maximum removals of total nitrogen (71.74%), total phosphorus (97.64%), total organic carbon (31.35%), chemical oxygen demand (56.70%), biological oxygen demand (20.68%) and ammonium (100%). These results show that this microalgae consortium is a promising alternative treatment for wastewaters of the leather wet-end and finishing steps.

The catalytic effect of TiO2 during the pyrolysis of Tetraselmis chuii (T.chuii) microalgae was studied using a thermal analyzer. Pyrolysis experiment was occupied on the sample that was a mixture of 10 mg microalgae and 5% TiO2 and the result was compared with microalgae and microalgae with 3% TiO2. The presence of 5% TiO2 into the microalgae affected decreasing the initial and final temperatures of degradation by approximately 17 °C (at Stage 2) and 35 °C (at Stage 3) respectively. The activation energy that was evaluated using the Coats-Redfern method for Stage 2 indicated the decreasing value of around 18.39 kJ/mol and increases in Stage 3 by 3.27 kJ/mol. The overall results indicated that addition of TiO2 has significantly influenced the conversion process of T. chuii microalgae.

A marine green microalga, Tetraselmis sp., has been studied for the production of biomass and lipids in seawater culture. Since carbohydrate and lipid biosynthesis are competitive metabolic pathways, we attempted to increase lipid synthesis in Tetraselmis by inhibiting carbohydrate synthesis. The main regulatory enzyme in the starch synthesis pathway is ADP-glucose pyrophosphorylase (AGP). AGP loss-of-function mutants were developed using the CRISPR-Cas9 ribonucleoprotein (RNP) delivery system. AGP mutants showed a slight decrease in growth. However, the lipid content in two AGP mutants was significantly enhanced by 2.7 and 3.1 fold (21.1% and 24.1% of DCW), respectively, compared to that in the wild type (7.68% of DCW) under nitrogen starvation. This study is an example of metabolic engineering by genetic editing using the CRISPR-Cas9 RNP method in marine green microalgae. Consequently, starchless Tetraselmis mutants might be considered potential producers of lipids in seawater cultures.

The Deepwater Horizon oil spill released millions of barrels of crude oil into the Gulf of Mexico, and saw widespread use of the chemical dispersant Corexit. We assessed the role of traits, such as cell size, cell wall, motility, and mixotrophy on the growth and photosynthetic response of 15 phytoplankton taxa to oil and Corexit. We collected growth and photosynthetic data on five algal cultures. These responses could be separated into resistant (Tetraselmis astigmatica, Ochromonas sp., Heterocapsa pygmaea) and sensitive (Micromonas pusilla, Prorocentrum minimum). We combined this data with 10 species previously studied and found that cell size is most important in determining the biomass response to oil, whereas motility/mixotrophy is more important in the dispersed oil. Our analysis accounted for a third of the variance observed, so further work is needed to identify other factors that contribute to oil resistance.

The way out of the energy crisis is to divert national energy needs with the use of new and renewable energy. Bioenergy such as biodiesel is the expected one of those. Algae which has the potential to be used as raw material for making biodiesel is microalgae because it is easier in its cultivation. The microalgae used in this study were Nannochloropsis oculata and Tetraselmis chuii. Microalgae that have been harvested in the pasta form are extracted to obtain the oil then processed into biodiesel with an ultrasonic device. The transesterification reaction ran at 65oC with a 1% K2CO3 catalyst. The variables applied were the ratio of oil: methanol (1:5; 1:10; 1:15) and reaction time (1 and 3 hours). The biodiesel produced was then tested for acid numbers, %FFA, density, viscosity, and GC-MS analysis. The amount of N. oculata and T. chuii obtained from harvesting was 591.75 and 460.11 grams, respectively. The yield of oil extracted from N. oculata and T. chuii was 46.47% and 39.31%. Biodiesel yield obtained from N. oculata between 72.19-74.33% with the highest yield for N3 sample, meanwhile in T. chuii between 69-72.95% with the highest gain for T3 sample. In general, biodiesel samples meet national standard SNI for Biodiesel in density, viscosity and acid number. The methyl ester content of the GC-MS test in the best biodiesel samples is N1 sample at 68.4% and T6 sample at 79.49%.

This study evaluated the survival, growth, and larval quality of the spotted rose snapper L. guttatus during a critical developmental period when mass mortalities often occur (at 15 to 24 days post-hatch, DPH), from eating live food to beginning of formulated feed consumption. At first feeding, a large batch of snapper larvae was fed a mixture of the microalgae Tetraselmis and Isochrysis, the rotifer B. plicatilis, and the copepod P. crassirostris. Thereafter (15 DPH), a total of 1800 larvae (5.3 ± 1.3 mm total length) were randomly selected from the large batch and assigned to three dietary treatment groups in 300 L triplicate tanks at a density of 200 larvae tank−1: Group 1 was fed the copepod Cyclopina sp. (CY) only, but they (the copepods) were an assortment of life stages and sizes. Group 2 was fed a mixture of both copepods (CY) and enriched Artemia nauplii (Mx), and Group 3 was fed only enriched Artemia sp. nauplii (AR). Larval quality was evaluated as the tolerance of 24 DPH larvae to a short-term (1.5 min) air exposure stress test. The percent survival of larvae was significantly (p 0.05), were observed in lengths measurements of the larvae fed the different diets. The higher survival estimates found in our studies were attributed primarily to the prominent jerky swimming movement of the copepods, and the wide variety of sizes in the copepod culture available for the snapper larvae to prey on, thus increasing capture of the copepods and reducing cannibalism.

The industrial microalga Tetraselmis sp. CTP4 is a promising candidate for aquaculture feed, novel food, cosmeceutical and nutraceutical due to its balanced biochemical profile. To further upgrade its biomass value, carotenogenesis was investigated by testing four environmental factors, namely temperature, light intensity, salinity and nutrient availability over different growth stages. The most important factor for carotenoid induction in this species is a sufficient supply of nitrates leading to an exponential growth of the cells. Furthermore, high temperatures of over 30 degrees C compared to lower temperatures (10 and 20 degrees C) induced the accumulation of carotenoids in this species. Remarkably, the two different branches of carotenoid synthesis were regulated depending on different light intensities. Contents of beta-carotene were 3-fold higher under low light intensities (33 mu mol m(-2) s(-1)) while lutein contents increased 1.5-fold under higher light intensities (170 and 280 mu mol m(-2) s(-1)). Nevertheless, highest contents of carotenoids (8.48 +/- 0.47 mg g(-1) DW) were found upon a thermal upshift from 20 degrees C to 35 degrees C after only two days at a light intensity of 170 mu mol m(-2) s(-1). Under these conditions, high contents of both lutein and beta-carotene were reached accounting for 3.17 +/- 0.18 and 3.21 +/- 0.18 mg g(-1) DW, respectively. This study indicates that Tetraselmis sp. CTP4 could be a sustainable source of lutein and beta-carotene at locations where a robust, euryhaline, thermotolerant microalgal strain is required. Funding Agency Portuguese Foundation for Science and Technology UID/Multi/04326/2019 SFRH/BD/115325/2016 SFRH/BD/140143/2018 SFRH/BD/105541/2014 0055 ALGARED+ 05 INTERREG V-A -Espana Portugal project national Portuguese funding PPBI-POCI-01-0145-FEDER-22122 Nord University info:eu-repo/semantics/publishedVersion

Antimicrobial screening programmes have shown that microalgae constitute a rich source of secondary metabolites exhibiting antimicrobial activity against human and aquaculture pathogens. In this study, extracts from 80 newly isolated marine and freshwater microalgae strains were tested for antimicrobial activity against 6 pathogens (Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus and Candida albicans). Principal Component Analysis and Hierarchical Clustering analyses (PCA-HC) of 4320 disc diffusion inhibition zones defined three main groups comprising strains with polar fractions inhibiting gram-positive bacteria, strains which exhibited broad spectrum activity and strains with non-polar fractions inhibiting gram-positive bacteria and C. albicans. Minimum Inhibitory Concentration (MIC) values were determined for 23 promising strains, which returned an activity threshold ≥15 mm inhibition zone diameter by disc diffusion method for at least one pathogen. The relationship between spectral quality and antimicrobial activity was further investigated for 5 promising strains (diatom Stauroneis sp. LACW_24, haptophyte Prymnesium sp. DMGCW_41, and chlorophytes cf. Chlorococcum sp. DMGCW_43, cf. Micractinium sp. LACW_01 and Tetraselmis sp. LACW_06), indicating a significantly higher bioactivity under blue light for the chlorophytes and red light for the diatom Stauroneis sp. LACW_24. Polar fractions from cf. Chlorococcum sp. DMGCW_43 and Stauroneis sp. LACW_24 possessed broad spectrum antibacterial activity with MIC values of 157 μg/mL and 875 μg/mL against P. aeruginosa, 157 μg/mL and 1000 μg/mL against E. coli, 438 μg/mL and 875 μg/mL against B. subtilis and E. faecalis, 110 μg/mL and 219 μg/mL, against S. aureus, respectively. This screening programme has led to the identification of several strains with promising antimicrobial activity. In addition, the manipulation of LED-based spectral quality to enhance the bioactivity of antimicrobial components within several candidate strains is described for the first time.

Tetraselmis is a genus of quadriflagellated single-celled green algae belonging to the Phylum Chlorophyta, commonly used in aquaculture with very promising biotechnological potential. The varied morphological characteristics, in some cases, have led to confusion in taxonomic identification. To solve this problem, new techniques based on molecular markers and restriction enzymes can ensure the identification of microalgae without sequencing. This study aimed to compare in silico modeling with an experimental restriction pattern based on the 18S rDNA gene for the identification of a microalgae strain. The strain grew in a culture medium, based on organic fertilizer. Theoretical analyses allowed the design of three primers based on the alignment of eight sequences obtained from NCBI, applying the Geneious Prime® 2019 and V1.3 and Oligo Calculator version 3.2. programs. The in silico restriction patterns was obtained with the NEBcutter v2.0 program. Experimental analyses began with the extraction of the DNA using the TENS protocol, then PCR amplification using PM-016F/PM-016R and PM-001F/PM-016R primers of 18S rDNA and finally the product was digested with BbvCI and Eco53kI; BstUI, RsaI and MspI enzymes. The DNA concentration extraction reached 3200 ng µl-1 and a purity of 2.0. The PCR amplified two products: 950 bp and 1400 bp, which brought us closer to identifying the microalgae. The in silico modeling and experimental restriction patterns showed similar fragments. In this way, the efficient response of restriction enzymes was demonstrated by confirming that the PM013 strain corresponds to the Tetraselmis genus. This method can be considered as a fast and safe alternative to identify wild microalgae in a basic molecular biology laboratory.

Dinoflagellate paralytic shellfish toxin (PST) production is mediated by several abiotic and biotic factors. This study compared the relative importance of nitrogen source and concentration, prey alarm cues and grazer presence on toxin production of the marine dinoflagellate Alexandrium catenella (Group I, strain BF-5). In separate assays run under either nutrient-replete (F/2 medium) or nutrient-depleted (filtered seawater) conditions, PST production of A. catenella was measured as a function of varying concentrations of added nitrogen sources (ammonium and urea), alarm cues from lysed conspecific (A. catenella Group I strains) and interspecific (the diatom, Thalassiosira weissflogii, and the green flagellate, Tetraselmis sp.) algae, and the presence of a grazer (the copepod Acartia hudsonica). Results showed that addition of ammonium or urea did not increase PST production. Unexpectedly, interspecific alarm cues increased toxin production but conspecific ones did not. Grazer presence dramatically induced PST production in A. catenella, irrespective of nutrient conditions, and this effect was an order of magnitude greater than any of the other variables tested. These results corroborate previous studies on grazer-induced PST production, and support the hypothesis that grazer-induced toxin production is not an experimental artifact, but rather a prey defense mechanism.

In the process of modernization and development, a human being always needed energy, which increased the dependency on the available sources of fossil fuel. Tetraselmis,a green algal genus belong to the order Chlorodendrales, are described by their strong green coloured chloroplast, flagellated cell bodies, and the occurrence of a pyrenoid within the chloroplast. In this study, four different strains of Tetraselmis species were successfully isolated from the saltpans Kovelong, Chennai, Tamil Nadu, India. The isolated strains were cultured in the normal basal medium and their morphological features were subsequently studied. The species of Tetraselmis straiata (T. straiata) Butcher BBRR1 was confirmed using molecular identification of 18S rRNA gene analysis and its observed systematic position. Among the four different isolates, T. straiata Butcher BBRR1 recorded a highest biomass concentration of 0.58 ± 0.021 g L-1, 15% lipids, 19% proteins and 17% carbohydrates when it grown under laboratory condition. Whereas, in open raceway ponds, T. straiata BBRR1 produced 0.95 ± 0.06 g L-1 biomass, 19% lipids, 28% proteins and 21% carbohydrates in an modified CFTRI I medium. The fatty acids profile of T. straiata Butcher BBRR1showed the presence of 33.14 % Palmitic acid, 22.64% 11- Octadecenoic acid and 21.94% Heptadecanoic acid. Since T. straiata BBRR1 can be cultivated in open ponds without a major contaminations, this species can be used as novel biomass feedstock to produce biofuels. This study may suggest the potential of T. straiata BBRR1 for biofuel production and could compete the energy demand in the future. In addition, this species contains healthful components of carotenoids, lipids and proteins, all these may provide a health benefits beyond basic nutrition.

Biomass harvesting is one of the most expensive steps of the whole microalgal production pipeline. Therefore, the present work aimed to understand the effect of salinity on the growth performance, biochemical composition and sedimentation velocity of Tetraselmis sp. CTP4, in order to establish an effective low-cost pilot-scale harvesting system for this strain. At lab scale, similar growth performance was obtained in cultures grown at salinities of 5, 10 and 20 g L-1 NaCl. In addition, identical settling velocities (2.4-3.6 cm h-1) were observed on all salinities under study, regardless of the growth stage. However, higher salinities (20 g L-1) promoted a significant increase in lipid contents in this strain compared to when this microalga was cultivated at 5 or 10 g L-1 NaCl. At pilot-scale, cultures were cultivated semi-continuously in 2.5-m3 tubular photobioreactors, fed every four days, and stored in a 1-m3 harvesting tank. Upon a 24-hour settling step, natural sedimentation of the microalgal cells resulted in the removal of 93% of the culture medium in the form of a clear liquid containing only vestigial amounts of biomass (0.07 ± 0.02 g L-1 dry weight; DW). The remaining culture was recovered as a highly concentrated culture (19.53 ± 4.83 g L-1 DW) and wet microalgal paste (272.7 ± 18.5 g L-1 DW). Overall, this method provided an effective recovery of 97% of the total biomass, decreasing significantly the harvesting costs. Agência financiadora Portuguese national budget P2020 Foundation for Science and Technology (FCT) CMAR/Multi/04326/2013 ALGARED+ 1398 EP - INTERREG V-A Espana Portugal project ALGACO2 project 023310 COST Action 1408 - European Network for Bio-products FCT SFRH/BD/105541/2014 info:eu-repo/semantics/publishedVersion

Aims To describe the biofilm microbiota associated with various feeding phases during larval common dentex (Dentex dentex) culture. Methods and results A targeted metagenomic (metagenetic) study was performed by means of 16S rRNA gene-based PCR and NextGen pyrosequencing. The resulting dataset was scrutinized with microbial community analysis software (r packages) using r/Rstudio. While median observed and estimated alpha-diversities were 171 ± 38 and 207 ± 27 taxa, respectively, 72·1-85·8% of individual biofilm communities comprised only 27-46 taxa. Members of the genus Methylobacterium and family Rhodobacteraceae dominated biofilms formed during all feeding phases while genera Nannochloropsis and Tetraselmis microalgae were major constituents of biofilms during rotifer live feeding. Both potential fish pathogenic genera, for example, Vibrio and putatively probiotic taxa, for example, Phaeobacter gallaeciensis were identified. Conclusions Relatively stable biofilm communities were identified during each feeding phase but varied significantly between feeding phases, most likely in response to the introduction of live feed/microalgae-associated bacteria into rearing tanks. Significance and impact of the study The structure of the bacterial communities identified represents a 'template' for successful larval dentex culture and provides a foundation for future investigations into failed production cycles.

The use of microalgae in biotechnological processes has received much attention worldwide. This is primarily due to the fact that they are inexpensive to grow, requiring only sunlight and CO2, whilst lending themselves to a range of uses, such as to reduce CO2 levels, as fish feed, in biofuel production, for the generation of secondary metabolites of interest, and in bioremediation. These features mean that microalgae are excellent candidates for the implementation of a range of eco-friendly technologies. Here, we investigated the behavior and feasibility of the use of the microalgal strain Tetraselmis marina AC16-MESO against heavy metal contamination focused on potential use in bioremediation. The following key parameters were recorded: (i) the sedimentation efficiency, which reached 95.6% after five hours of decantation; (ii) the ion tolerance (Ca2+, Co2+, Cu2+, Fe3+, Mn2+ and Ni2+) at concentrations of 0.1, 1.0, 5.0, 10.0 and 20.0 mg*L−1 and (iii) ion removal efficiency (Cu2+, Fe3+ and Mn2+). Our results indicated a higher tolerance for iron and calcium (20 ± 1.10 mg*L−1; 100 ± 8.10 mg*L−1), partial to nickel, manganese and copper (4.4 ± 0.10 mg*L−1; 4.4 ± 0.15 mg*L−1; 5 ± 1.25 mg*L−1) and less for cobalt (0.1 ± 0.20 mg*L−1). Moreover, removal efficiency of 40–90% for Cu2+, 100% for Fe3+, and 20–50% for Mn2+ over a 72 hours period, for ion concentrations of 1.0 and 5.0 mg*L−1.

High-throughput sequencing of ocean biomes has revealed vast eukaryotic microbial diversity, a significant proportion of which remains uncharacterized. Here we use a temporal approach to understanding eukaryotic diversity at the Scripps Pier, La Jolla, California, USA, via high-throughput amplicon sequencing of the 18S rRNA gene, the abundances of both Synechococcus and Synechococcus grazers, and traditional oceanographic parameters. We also exploit our ability to track operational taxonomic units (OTUs) temporally to evaluate the ability of 18S sequence-based OTU assignments to meaningfully reflect ecological dynamics. The eukaryotic community is highly dynamic in terms of both species richness and composition, although proportional representation of higher-order taxa remains fairly consistent over time. Synechococcus abundance fluctuates throughout the year. OTUs unique to dates of Synechococcus blooms and crashes or enriched in Synechococcus addition incubation experiments suggest that the prasinophyte Tetraselmis sp. and Gymnodinium-like dinoflagellates are likely Synechococcus grazers under certain conditions, and may play an important role in their population fluctuations.

An intense bloom of Tetraselmis sp., producing strong water discoloration was observed from December 28th of 2005 through January 10th of 2006 in the Valparaiso Bay (32Âo 57’S; 71Âo 33’W). Blooms of Tetraselmis sp. have never been reported in this bay, or along the coast of Chile. The confluence of a series of environmental conditions observed before and during the bloom such as: high solar radiation, anomalous UV radiation levels, high sea surface temperatures, water stratification and high nutrient concentrations may have contributed to the development of this unique event.

Due to the possible depletion of fossil fuels in the near future and the necessity of finding new food sources for a growing world population, marine microalgae constitutes a very promising alternative resource, which can also contribute to carbon dioxide fixation. Thus, seven species (Chaetoceros calcitrans, Chaetoceros gracilis, Isochrysis galbana, Nannochloropsis gaditana, Dunaliella salina, Tetraselmis suecica, and Tetraselmis chuii) were grown in five serial batch cultures at a bench scale under continuous illumination. The batch cultures were inoculated with an aliquot that was extracted from a larger-scale culture in order to obtain growth data valid for the entire growth cycle with guaranteed reproducibility. Thus, measurements of optical density at several wavelengths and cell counting with a haemocytometer (Neubauer chamber) were performed every one or two days for 22 days in the five batch cultures of each specie. Modeling of cell growth, the relationship between optical density (OD) and cell concentration and the effect of wavelength on OD was performed. The results of this study showed the highest and lowest growth rate for N. gaditana and T. suecica, respectively. Furthermore, a simple and accurate discrimination method by performing direct single OD measurements of microalgae culture aliquots was developed and is already available for free on internet. PRUCV2017-162-001 grant from the Universidad Católica de Valencia San Vicente Mártir PRUCV2018-231-001 grant from the Universidad Católica de Valencia San Vicente Mártir PRUCV2017-231-001 grant from the Universidad Católica de Valencia San Vicente Mártir PRUCV2018-162-001 grant from the Universidad Católica de Valencia San Vicente Mártir Ciencias del Mar

Vampyrellids (Vampyrellida, Rhizaria) are a major group of predatory amoebae known primarily from freshwater and soil. Environmental sequence data indicate that there is also a considerable diversity of vampyrellids inhabiting marine ecosystems, but their phenotypic traits and ecology remain largely unexplored. We discovered algivorous vampyrellids of the filoflabellate morphotype in coastal habitats in Atlantic Canada, established cultures by single-cell isolation, and characterised three strains using light microscopy, SSU rRNA gene sequencing, feeding experiments and growth experiments at various salinities. These strains exhibit orange, discoid trophozoites with ventral filopodia, moving granules ("membranosomes"), and rolling locomotion, similar to freshwater species previously assigned to Hyalodiscus Hertwig & Lesser, but here moved to Placopus Schulze (due to homonymy with Hyalodiscus Ehrenberg). SSU rRNA gene phylogenies place our strains in two distinct positions within "lineage B3" (here referred to as Placopodidae). Based on these morphological, habitat and molecular data, we describe two new species, Placopus melkoniani sp. nov. and Placopus pusillus sp. nov., both of which feed on chlorophyte flagellates (Tetraselmis, Pyramimonas) and the cryptophyte Chroomonas. They perforate the theca of Tetraselmis to extract the protoplast, and thereby represent the first vampyrellids known to degrade the biochemically exotic cell wall of the Chlorodendrales (Chlorophyta, Viridiplantae).