Scenedesmus Quadricauda Research Articles

Algicidal efficiency and mechanism of Phanerochaete chrysosporium against harmful algal bloom species

Algal blooms pose serious ecological problems, threaten biological safety, and cause great economic losses. While white-rot fungi have attracted worldwide attention for their ability to inhibit algal blooms, the algicidal efficiency and mechanism of Phanerochaete chrysosporium have not been reported to date. In this study, Cryptomonas obovata FACHB-1301, Oscillatoria sp. FACHB-1083, and Scenedesmus quadricauda FACHB-507 were co-cultured with P. chrysosporium under optimum conditions with a fungal dosage of 250mg−l, pH of 7.0 and dissolved oxygen content of 7.0mg−l. The results showed that the chlorophyll-a content, dehydrogenase activity, and soluble protein content of the three algae decreased, whereas the malondialdehyde content increased after 48h of co-culture. Flow cytometry showed that P. chrysosporium damaged the membranes and nucleic acid of the algal cells, thereby causing cell death. Fourier transform infrared spectroscopy results indicated that the pyrrole ring of chlorophyll-a was degraded, and scanning electron microscopy revealed that the structure of the algal cells was seriously damaged by P. chrysosporium. These results demonstrated that the algal cells were severely damaged by P. chrysosporium and were finally degraded directly by the fungus, which has superior properties as algicidal agent for its low cost and safety compared to physical and chemical methods.

Effect of diethyl aminoethyl hexanoate on the accumulation of high-value biocompounds produced by two novel isolated microalgae

The low productivity of microalgae has restricted scale-up application of microalgae-based biodiesel processes. Diethyl aminoethyl hexanoate (DA-6) was investigated to enhance the biomass and metabolite productivity. At a very low concentration (10−7M) DA-6 made Chlorella ellipsoidea SDEC-11 and Scenedesmus quadricauda SDEC-13 obtain enlarged cell size, 114mgL−1d−1, 101mgL−1d−1 biomass productivity and 39.13mgL−1d−1, 32.69mgL−1d−1 lipid productivity, respectively. Biomass and lipid productivity of SDEC-11 and SDEC-13 were 100mgL−1d−1 and 30.05mgL−1d−1, 94mgL−1d−1 and 28.43mgL−1d−1, respectively, without DA-6. Twice hormone dose in 10−6M DA-6 medium resulted in higher biomass productivity (106mgL−1d−1) and longer exponential growth of SDEC-13. DA-6 also ensured the property of microalgae biodiesel to meet the EN 14214 standard. The current investigation demonstrated that DA-6 accelerated the microalgae growth and simultaneously improved the quality and quantity of lipid for biodiesel production.

Improvement in Oil Production by Increasing Malonyl-CoA and Glycerol-3-Phosphate Pools in Scenedesmus quadricauda.

In recent years, microalgae have attracted considerable interest as a biofuel resource owing to their rapid growth, tolerance to harsh conditions, and ability to accumulate a large amount of triacylglycerols (TAGs). However, the economic effectiveness of algal biofuel is still low. In this study, we attempted to increase oil production of the microalga Scenedesmus quadricauda by elevating intracellular malonyl-CoA and glycerol-3-phosphate (G3P) pools. To increase intracellular oil content, yeast-derived genes encoding acetyl-CoA carboxylase (ACC1), glycerol kinase (GPD1), and glycerol-3-phosphate dehydrogenase (GUT1) were overexpressed under the control of CaMV 35S and NOS promoters with SV40 large T antigen components. Fatty acid profiling, G3P content, and the number of cells with high oil content were analyzed by gas chromatography-mass spectrometry, G3P assay kit, and flow cytometry, respectively. Overexpression of ACC1 increased the total fatty acid content by 1.6-fold. Overexpression of GPD1 and GUT1 increased intracellular G3P content by 1.6- and 1.9-fold, respectively. Multi-gene expression of ACC1, GPD1, and GUT1 increased the number of cells with high oil content by 1.45-fold compared with that observed with the wild-type. This study is the first to report increased oil production by overexpression of the key genes (ACC1, GPD1, and GUT1) for TAG biosynthesis in microalgae.

Algal Decay Resistance of Conventional and Novel Wood-Based Composites

Measures of the resistance to algal decay of conventional (medium density fiberboard [MDF] and plywood) and novel wood-based composites (WPC) were investigated in the same or varying wood species by using an artificial accelerated test with four mixed algal suspensions (Chlorella vulgaris, Ulothrix sp., Scenedesmus quadricauda, and Oscillatoria sp.). The morphology characterization of the surface and fracture of the specimens was analyzed using scanning electron microscopy (SEM) and a digital instrument. The pH value and the mass loss rate of the different wood species were also tested. The results showed that the algal resistance of the MDF and plywood were superior to that of the WPC of the same wood species. Furthermore, the algal resistance capacity of WPC made from various wood species were ranked as: Liquidambar formosana > Cunninghamia lanceolata and Melaleuca leucadendra > Ricinus communis > Eucalyptus grandis × E. urophylla and Pinus massoniana. There was a close relationship between the pH value and the algal resistance level; as the pH value increased, the alga resistance of the WPC also increased. The algal colonization only had a negative effect on the appearance of the samples.

Salinity tolerance of four freshwater microalgal species and the effects of salinity and nutrient limitation on biochemical profiles

Microalgae are ideal candidates for bioremediation and biotechnological applications. However, salinity and nutrient resource availability vary seasonally and between cultivation sites, potentially impacting on biomass productivity. The aim of this study was to screen pollutant-tolerant freshwater microalgae (Desmodesmus armatus, Mesotaenium sp., Scenedesmus quadricauda and Tetraedron sp.), isolated from Tarong power station ash-dam water, for their tolerance to cultivation at a range of salinities. To determine if biochemical composition could be manipulated, the effects of 4-day nutrient limitation were also determined. Microalgae were cultured at 2, 8, 11 and 18 ppt salinity, and nutrient uptake was monitored daily. Growth, total lipid, fatty acid (FA), and amino acid contents were quantified in biomass harvested while nutrient-replete and, after 4 days, nutrient-deplete. D. armatus showed the highest salinity tolerance actively growing in up to 18 ppt while Mesotaenium sp. was the least halotolerant with decreasing growth rates from 11 ppt. However, Mesotaenium sp. at 2 and 8 ppt had the highest biomass productivity and nutrient requirements of the four species, making it ideal for nutrient remediation of eutrophic freshwater effluents. Salinity and nutrient status had minimal influence on total lipid and FA contents in D. armatus and Mesotaenium sp., while nutrient depletion induced an increase of total lipid and FAs in S. quadricauda and Tetraedron sp., which was further increased with increasing salinity. As none of the growth conditions affected amino acid profiles of the species, these findings provide a basis for species selection based on site-specific salinity conditions and nutrient resource availability.

Dynamic modeling predicts continued bioaccumulation of polybrominated diphenyl ethers (PBDEs) in smallmouth bass (Micropterus dolomiu) post phase-out due to invasive prey and shifts in predation

Unprecedented food chain links between benthic and pelagic organisms are often thought to disrupt traditional contaminant transport and uptake due to changes in predation and mobilization of otherwise sequestered pollutants. A bioaccumulation model for polybrominated diphenyl ethers (PBDEs) is developed to simulate increases in biotic congener loads based upon trophic transfer through diet and gill uptake for a Lake Erie food chain including two invasive species as a benthic-pelagic link. The model utilizes species-specific bioenergetic parameters in a four-level food chain including the green alga Scenedesmus quadricauda, zebra mussels (Dreissena polymorpha), round goby (Appollonia melanostoma), and the smallmouth bass (Micropterus dolomiu). The model was calibrated to current biotic concentrations and predicts an increase in contaminant load by almost 48% in the upper trophic level in two years. Validation to archival data resulted in <2% error from reported values following a two-year simulation.

Toxicological assessment of hospital wastewater in different treatment processes.

This study surveyed the hospital wastewater characters focusing on antibiotic contamination in seven hospitals in Bangkok. It detected 19 antibiotics of which the high-frequent detection were quinolones such as ofloxacin + levofloxacin, norfloxacin, ciprofloxacin including sulfamethoxazole. Norfloxacin and ciprofloxacin appeared the highest concentrations of 12.11 and 9.60μg/L, respectively. Most antibiotic concentrations in the wastewaters of the studied hospitals gave a good correlation (r 2 = 0.77-0.99) to the amount of usage. In this study, batch acute toxicity tests were performed to assess the toxicity of hospital wastewater on mixed liquor, freshwater algae (Chlorella vulgaris and Scenedesmus quadricauda), and microcrustacean (Moina macrocopa). The hospital wastewaters could inhibit the mixed liquor growth and gave similar toxic levels among test species: algae and microcrustacean (9.81-13.63 and 2.62-3.09TU, respectively). The conventional activated sludge (CAS) and rotating biological contactor (RBC) could remove fluoroquinolones and tetracycline via biomass adsorption. After treatment, most of treatment could reduce the toxicity. Nevertheless, the effluent gave slight toxicity on some test species which might be caused from chlorination and a common toxicant (NH3-N).

Chronic effects of the ionic liquid [C4mim][Cl] towards the microalga Scenedesmus quadricauda

Chronic effects of the ionic liquid [C4mim][Cl] (mp 73 °C) towards the microalga, Scenedesmus quadricauda were studied by flow cytometry, monitoring multiple endpoints of cell density, esterase activity, membrane integrity, reactive oxygen species and chlorophyll fluorescence. Toxicity was clearly in evidence, and although increased esterase activity indicated hormesis during initial exposure to [C4mim][Cl], inhibition of both esterase activity and chlorophyll fluorescence became apparent after 3 days. Cell density was also decreased by culturing with [C4mim][Cl], but this effect was clearly concentration-dependent and only became significant during the second half of the experiment. In contrast, [C4mim][Cl] had only a modest effect on reactive oxygen species (ROS) and caused little damage to cell membranes.

Comparing Acute Effects of a Nano-TiO2 Pigment on Cosmopolitan Freshwater Phototrophic Microbes Using High-Throughput Screening.

Production of titanium-dioxide nanomaterials (nano-TiO2) is increasing, leading to potential risks associated with unintended release of these materials into aquatic ecosystems. We investigated the acute effects of nano-TiO2 on metabolic activity and viability of algae and cyanobacteria using high-throughput screening. The responses of three diatoms (Surirella angusta, Cocconeis placentula, Achnanthidium lanceolatum), one green alga (Scenedesmus quadricauda), and three cyanobacteria (Microcystis aeruginosa, Gloeocapsa sp., Synechococcus cedrorum) to short-term exposure (15 to 60 min) to a common nano-TiO2 pigment (PW6; average crystallite size 81.5 nm) with simulated solar illumination were assessed. Five concentrations of nano-TiO2 (0.5, 2.5, 5, 10, and 25 mg L-1) were tested and a fluorescent reporter (fluorescein diacetate) was used to assess metabolic activity. Algae were sensitive to nano-TiO2, with all showing decreased metabolic activity after 30-min exposure to the lowest tested concentration. Microscopic observation of algae revealed increased abundance of dead cells with nano-TiO2 exposure. Cyanobacteria were less sensitive to nano-TiO2 than algae, with Gloeocapsa showing no significant decrease in activity with nano-TiO2 exposure and Synechococcus showing an increase in activity. These results suggest that nanomaterial contamination has the potential to alter the distribution of phototrophic microbial taxa within freshwater ecosystems. The higher resistance of cyanobacteria could have significant implications as cyanobacteria represent a less nutritious food source for higher trophic levels and some cyanobacteria can produce toxins and contribute to harmful algal blooms.

Combined effect of atrazine and copper on the growth, biomass production, morphology and antioxidant response of Scenedesmus quadricauda

:In recent years, various investigations have been carried out on the toxic effects of atrazine to different algae. However, none of these studies have considered the combined effects of metals and atrazine on any microalga. The toxicity of atrazine to microalgae depends on its interaction with the physical and chemical conditions prevalent in the aquatic ecosystem at the time of exposure. The aim of this study was to investigate the combined effect of copper (Cu) and atrazine on the growth, biomass production, morphological variation, protein production and antioxidant enzyme responses of Scenedesmus quadricauda under controlled laboratory conditions. The combination of Cu and atrazine resulted in significantly lower growth and biomass production than Cu or atrazine alone. The ability of the alga to produce multicellular coenobia was significantly compromised after exposure to Cu and atrazine, while the proportion of unicells increased. Copper/atrazine stress stimulated total protein production and up-regulated the activity of superoxide dismutase, catalase, peroxidase and glutathione S transferase. The combination of Cu and atrazine was very toxic to S. quadricauda as it inhibited its growth, biomass production, and morphology, but increased antioxidant enzyme activities.

Effects of far red light on the induction changes of prompt and delayed fluorescence and the redox state of P700 in Scenedesmus quadricauda

The spectral composition of sunlight in natural aquatic habitats depends on the depth of submergence and the solar time. Changes in the fractional amount of far-red light (FRL) in the total photon flux are associated with the redistribution of light energy absorbed by the two photosystems of photosynthesis. Experiments with a culture of Scenedesmus quadricauda revealed the influence of FRL preillumination on photosynthetic electron transport and associated processes in microalgae. The plant efficiency analyzer M-PEA-2 was used to measure simultaneously the induction curves of prompt fluorescence, delayed fluorescence, and the redox transients of chlorophyll P700. The results are discussed in terms of the action of FRL preillumination on cyclic and noncyclic electron flows with account for relocation of the mobile light-harvesting complex of photosystem II during reversible State 1–State 2 transitions. Essential similarities and substantial distinctions have been revealed in the effects of FRL on photosynthetic electron flows in microalgae and higher plant leaves.

Enhanced lipid accumulation and biomass yield of Scenedesmus quadricauda under nitrogen starved condition

The experimental results revealed that the 2.27-fold lipid yield was enhanced in nitrogen-depleted condition (226mg/L) when compared to nitrogen rich condition (99.33mg/L). Since specific growth rate (SGR) is the single most criteria to decide the biomass yield of microalgae, SGR was analyzed. SGR of 0.33day−1 was observed with 0.47 doubling per day under nitrogen rich condition. However, low growth rate of 0.14day−1 with a doubling of 0.20 per day was recorded under nitrogen depleted condition. In accordance with SGR, the dry biomass yield was ranged from 0.055±0.005 to 1.394±0.010g/L in the presence of nitrogen, indicating the essentiality of major nutrient in the growth medium. The enhanced lipid accumulation under nitrogen starved condition by Scenedesmus quadricauda was perhaps achieved by adopting adverse environmental condition and possible increment in cell size in terms of length/breadth ratio (1.11).

Response of a phytoplanktonic assemblage to copper and zinc enrichment in microcosm.

The response of a laboratory-raised phytoplankton assemblage to copper and zinc enrichment was studied. Higher intracellular accumulation of both the test metals caused disappearance of metal sensitive species, loss of diversity and species richness, reduced growth rate, Chl a and biovolume; however, the community could recover after 14days of incubation. Cyanobacteria showed marked sensitivity to both the test metals besides some diatoms, such as, Cyclotella meneghiniana and Melosira granulata. Metal enrichment enhanced the relative abundance of species like Scenedesmus quadricauda, Oocystis borgei, Achnanthes exigua, Fragilaria capucina and Nitzschia amphibia, and these were apparently metal tolerant. Cu and Zn stress induces formation of lipid bodies (bigger in size as well as in number) and morphological abnormalities in diatoms. Among these two metals, Cu impact was higher than Zn despite the fact that the intracellular accumulation of Zn was higher than Cu. Deformed raphe and mixed deformities in diatoms were exclusively found under heavy metal stress which was well supported by regression analysis. Finally the present study gives new insight for using diatoms as an effective tool for biomonitoring and biofuel production.

Wpływ niektórych detergentów na przyrost biomasy Solanum lycopersicum i Scenedesmus quadricauda oraz na akumulację składników mineralnych u tych roślin [The effect of some detergents on the increase in biomass and the accumulation of mineral components in Solanum lycopersicum and Scenedesmus quadricauda

The investigation on water cultures of tomato seedlings and &lt;em&gt;Scenedesmus quadricauda&lt;/em&gt; colonies have shown that low doses of the detergents stimulate the growth of these plants. An intensified accumulation of N, P, Ca, Mg, Fe and a reduced accumulation of K-ions have been observed.

Phytoplankton community structure and water quality assessment of Hejiang River, a branch of Xijiang River, Pearl River drainage basin

为了解珠江流域西江支流贺江浮游藻类的分布并评价其水质情况,于2013年丰水期和枯水期对贺江的浮游藻类群落结构进行调查和分析,结果表明:调查期间共检出浮游藻类7门130种,其中丰水期7门63种,枯水期5门103种,浮游藻类群落组成以绿藻门、硅藻门和蓝藻门为主,丰水期绿藻门居多,硅藻门次之,藻细胞丰度平均值为2.13×10⁶cells/L;枯水期硅藻门最多,藻细胞丰度平均值为3.71×10⁶cells/L;优势种主要有水华微囊藻、卷曲鱼腥藻、小颤藻、啮蚀隐藻、短小舟形藻、变异直链藻、颗粒直链藻、四尾栅藻、集星藻、小球衣藻和小球藻.RDA分析表明,影响贺江浮游藻类群落分布的主要环境因子是氮、磷营养盐,综合营养状态指数显示贺江处于中营养水平.;To study the distribution of phytoplankton and evaluate water quality of Hejiang River, a branch of Xijiang River, Pearl River drainage basin, the community structure of phytoplankton was investigated and analyzed in wet and dry seasons in 2013.The results showed that a total of 130 species belonging to seven phyla of phytoplankton was identified.Including 63 species of seven phyla in wet season and 103 species of five phyla in dry season, phytoplankton community structure in Hejiang River was represented by Chlorophyta, Bacillariophyta and Cyanophyta.Chlorophyta was dominant in wet season, followed by Bacillariophyta.The mean value of phytoplankton density was 2.13×10⁶ cells/L.Bacillariophyta dominated the phytoplankton in dry season, and the mean value of phytoplankton density was 3.71×10⁶cells/L.The dominant species were Microcystis flos-aquae, Anabaena circinalis, Oscillatoria tenuis, Cryptomonas erosa, Navicula exigua, Melosira varians, Melosira granulata, Scenedesmus quadricauda, Actinastrum hantzschii, Chlamydomonas microsphaera and Chlorella valgaris.Based on RDA analysis, nitrogen and phosphorus were important environmental factors that affected the distribution of phytoplankton in Hejiang River.The river was classified as mesotrophic according to comprehensive trophic state index.

Capillary Electrophoresis Single-Strand Conformational Polymorphisms as a Method to Differentiate Algal Species.

Capillary electrophoresis single-strand conformational polymorphism (CE-SSCP) was explored as a fast and inexpensive method to differentiate both prokaryotic (blue-green) and eukaryotic (green and brown) algae. A selection of two blue-green algae (Nostoc muscorum and Anabaena inaequalis), five green algae (Chlorella vulgaris, Oedogonium foveolatum, Mougeotia sp., Scenedesmus quadricauda, and Ulothrix fimbriata), and one brown algae (Ectocarpus sp.) were examined and CE-SSCP electropherogram “fingerprints” were compared to each other for two variable regions of either the 16S or 18S rDNA gene. The electropherogram patterns were remarkably stable and consistent for each particular species. The patterns were unique to each species, although some common features were observed between the different types of algae. CE-SSCP could be a useful method for monitoring changes in an algae species over time as potential shifts in species occurred.

Effect of herbicides on photosynthetic electron transport and on the growth of the alga Scenedesmus quadricauda

The inhibitory effect of herbicides on the Hill reaction (with 2,6-dichloro-phenol-indophenol as acceptor) and their influence on development of the alga &lt;i&gt;Scenedesmus quadricauda&lt;/i&gt; was studied. The following herbicides were tested: 2,4-D, Gramoxone, Afalon, Kresamone, CIPC and Simazine. The results are discussed in terms of the mechanism of action of the investigated herbicides.

The influence of gibberellic acid and kinetin on the growth of Scenedesmus quadricauda (Turp.) Breb.

The influence of gibberellic acid (GA&lt;sub&gt;3&lt;/sub&gt;) and of kinetin (6-furfurylamino purine) on the increment of cell number increase in dry weight and upon protein level in &lt;i&gt;Scenedesmus quadricauda&lt;/i&gt; (Turp.) Bréb. was studied. It was found that 10&lt;sup&gt;-7&lt;/sup&gt; M GA&lt;sub&gt;3&lt;/sub&gt; stimulates at the same time cell growth and dry weight increase of the algae. No influence of GA&lt;sub&gt;3&lt;/sub&gt; upon the protein content was observed. Kinetin of 10&lt;sup&gt;-&lt;/sup&gt; M concentration stimulates in the initial growth phase cell multiplication and increases the protein level. This substance promotes the increment in dry weight however in the later phase of growth. Furthermore kinetin prolongs the viability of algae, extending the growth phase.

Removal of three and hexavalent chromium from aqueous solutions using a microalgae biomass‐derived biosorbent

Dry biomass of green microalgae, Scenedesmus quadricauda (Chlorophyta), was used as a biosorbent to remove Cr(III) and Cr(VI) from aqueous solutions using batch experiments. The biomass composed of 43.5% protein, 20.2% carbohydrate, and 9.2% lipid. Different functional groups including hydroxyl, amine and sulfoxide were observed in the biosorbent. The equilibrium time for the removal of Cr(III and VI) was 120 min. The maximum adsorption was obtained at pH 6 (98.3%) and pH 1 (47.6%) for Cr(III) and Cr(VI), respectively. The kinetics data was better fitted by the pseudo‐second‐order model for both Cr species. The biosorption of Cr(III) was described by the Langmuir and that of Cr(IV) by the Freundlich isotherm models. According to the Langmuir model, the maximum biosorption capacity was 58.47 and 46.51 mg g−1 for Cr(III) and Cr(VI), respectively. The regeneration of biosorbent was achieved by HNO3 (85%) for Cr(III) and NaOH (60%) solutions for Cr(VI). The application of dry microalgae biomass could be suitable as an alternative technology for the heavy metal removal from wastewater, especially for the small and medium industry. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 949–956, 2015

Integrated campus sewage treatment and biomass production by Scenedesmus quadricauda SDEC-13

The notion of wastewater treatment combined with biomass production is potential and prospective. Campus sewage was utilized twice in procession to cultivate the newly isolated microalgae Scenedesmus quadricauda SDEC-13. Nutrients was efficiently removed with the phosphorus and nitrogen removal efficiency nearly 100% and more than 70% respectively in twice use of campus sewage. Ammonium was consumed rapidly within five days in 1st use. There was no significant difference in the lipid and protein content but distinct difference in their respective productivity which is ascribed to the lower biomass productivity caused by limited nutrients in 2nd use. The diverse nutrient concentration in twice use of campus sewage and BG-11 had effects on the composition of fatty acids and amino acids. SDEC-13 performed better biodiesel quality compared with BG-11 medium and produced high quality protein when cultivated in campus sewage. Finally, the campus sewage after twice use reached the corresponding discharge standard.