Scenedesmus Quadricauda Research Articles

Wastewater valorization adopting the microalgae accelerated growth

Microalgal biomass cultivation as a byproduct of wastewater treatment represents an interesting opportunity for wastewater valorization. Several studies analyzed the growth of microalgae in urban and agricultural wastewaters, evaluating the potential of microalgae strains to remove organic pollutants. To assess the actual environmental impact of such an integrated system, life cycle assessment (LCA) provides the proper tools for a comprehensive and effective analysis. In this study, olive mill wastewaters (OMW) are chosen and the selected microalgal strains are Chlrorella vulgaris and Scenedesmus quadricauda. Technical activities were carried out to obtain, starting from OMW, a cultivation medium with the same composition of the synthetic substrate (BG 11) used to grow the selected microalgal strains. Then, by means of LCA, a comparison between the environmental burden of the different scenarios was performed. Particular attention was devoted to the environmental indicators and a sensitivity analysis was performed to account for the transportation of OMW from olive mills to a centralized OMW treatment plant. The results show that the wastewater valorization can bring about an environmental benefit if the treatment plant is properly located. This is largely due to the avoided impact of the OMW purification treatment.

Effect of Cadmium on Biomass, Pigmentation, Malondialdehyde, and Proline of Scenedesmus quadricauda var. longispina

Effects of cadmium (Cd(2+)) on biomass, pigmentation (chlorophyll a, b, and total carotene), malondialdehyde (MDA), and proline productions by Scenedesmus quadricauda var. longispina were investigated. Cadmium had inhibitory effect on the productions of biomass and pigmentation. Significant differences were found in pigment content among groups. On the other hand, Cd(2+) had a simulative effect on the production of MDA and proline by the alga. FTIR-ATR spectroscopy was used to examine active groups of algal biomass before and after Cd(2+) exposure. Results confirmed that amino, amide, and anionic groups had significant role on the biosorption of Cd(2+) by the alga. Increased accumulation of MDA and proline seemed to be an important strategy for alleviating metal-induced oxidative stress in S. quadricauda var. longispina.

On the polyphasic quenching kinetics of chlorophyll a fluorescence in algae after light pulses of variable length

This study reports on kinetics of the fluorescence decay in a suspension of the alga Scenedesmus quadricauda after actinic illumination. These are monitored as the variable fluorescence signal in the dark following light pulses of variable intensity and duration. The decay reflects the restoration of chlorophyll fluorescence quenching of the photosystem II (PSII) antennas and shows a polyphasic pattern which suggests the involvement of different processes. The overall quenching curve after a fluorescence-saturating pulse (SP) of 250-ms duration, commonly used in pulse amplitude modulation applications as the tool for estimating the maximal fluorescence (F m), has been termed P-O, in which P and O have the same meaning as used in the OJIP induction curve in the light. Deconvolution of this signal shows at least three distinguishable exponential phases with reciprocal rate constants of the order of 10, 10(2), and 10(3)ms. The size of the long (>10(3)ms) and moderate (~10(2)ms) lasting components relative to the complete quenching signal after an SP increases with the duration of the actinic pulse concomitantly with an increase in the reciprocal rate constants of the fast (~10ms) and moderate quenching phases. Fluorescence responses upon single turnover flashes of 30-μs duration (STFs) given at discrete times during the P-O quenching were used as tools for identifying the quencher involved in the P-O quenching phase preceding the STF excitation. Results are difficult to interpret in terms of a single-hit two-state trapping mechanism with distinguishable quenching properties of open and closed reaction centers only. They give support for an earlier hypothesis on a double-hit three-state trapping mechanism in which the so-called semi-closed reaction centers of PSII are considered. In these trapping-competent centers the single reduced acceptor pair [PheQ A](1-), depending on the size of photoelectrochemically induced pH effects on the Q B-binding site, functions as an efficient fluorescence quencher.

Resting Egg Production and Fatty Acid Enhancement in the Waterflea, Ceriodaphnia quadrangula, by Using Combination of Light Regime and Food

AbstractCombined effects of different light regimes, 6L:6D and 12L:12D (hours light : hours dark, L:D) and algal foods of Scenedesmus quadricauda (S) and Chlorella vulgaris (C) on ephippia production and fatty acid (FA) profile of Ceriodaphnia quadrangula were investigated. The highest resting egg production, density, and specific growth rate were obtained with 6L:6D+S; followed by 12L:12D+S treatment. The C16:0 varied from 16.2 to 22.16 mg/g dry weight (d.w.); C18:1n−9 from 11.03 to 14.94 mg/g d.w; C18:2n−6 from 9.79 to 20.24 mg/g d.w; and C18:3n−3 from 6.98 to 16.02 mg/g d.w. The amounts of C20:4n−6 (4.36 mg/g d.w) and C20:5n−3 (3.35 mg/g d.w) at 6L:6D+S were highest compared to other treatments. The maximum saturated fatty acids and monounsaturated fatty acids were obtained at 6L:6D+C while maximum polyunsaturated fatty acids observed at 6L:6D+S and 12L:12D+C. The resting egg production and FAs profile could be improved when the frequency of changes from light to dark were increased. Our findings also indicate a significant increase in the quantity of C18:3n−3 in C. quadrangula populations during resting egg formation, hence, implying that manipulation of light regime and algal food can improve performance of C. quadrangula as a live food in aquaculture industries, especially for larval feeding.

Effects of different light/dark regimes and algal food on growth, fecundity, ephippial induction and molting of freshwater cladoceran, Ceriodaphnia quadrangula

Combined effects of different light regimes and algal foods on population growth, ephippia (resting eggs) production, fecundity, molting and body size of Ceriodaphnia quadrangula were investigated. Four light/dark regimes in combination with two algal diets of Scenedesmus quadricauda (S) and Chlorella vulgaris (C) namely: 4L: 4D+S, 6L: 6D+S, 8L: 8D+S, 12L: 12D+S, 4L: 4D+C, 6L: 6D+C, 8L: 8D+C, and 12L: 12D+C were assigned to present study. The highest population density and growth rate were obtained at 12L:12D+C (1860 ind/l and 0.29/day) and 6L:6D+C (1760ind./l and 0.28/day), which were significantly different from other treatments (p<0.05). Ephippium production was affected by light/dark period, decreasing with increasing light duration when fed on S. quadricauda and increasing when fed C. vulgaris. Although the ephippium was observed at all treatments, significantly higher ephippium (285 eggs/l) were recorded at 4L:4D+S (p<0.05). Fecundity ranged between 0.67 and 3.00/female/day, with the lowest value occurring at 4L:4D+S and the highest at 6L:6D+S. The molting rate was significantly (p<0.05) different among the various treatments. The range of molting was 1.59–8.43/female/week, lowest at 4L:4D+C and the highest with 12L:12D+S. Based on our results, 12L:12D+S is recommended for growth and molting, and 4L:4D+S for ephippium production in C. quadrangula.

Ecotoxicological assessment of Inya R. Water and the Belovskoe Reservoir, Kemerovo Province

The results of toxicological analysis of water of the Inya R. and the Belovskoe Reservoir (the cooling pond of the Belovskaya SDPP), obtained in 2001, 2002, and 2008 by bioassaying methods are given. The test objects used in the study included photobacteria (Photobacterium phosphoreum), two types of protococcus algae (Chlorella vulgaris Beijer, Scenedesmus quadricauda (Turp.) Breb.) and two types of entomostracans (Daphnia magna Straus, Ceriodaphnia affinis Lillijeborg). The distribution of water toxicity in the Belovskoe Reservoir and the Inya River, flowing into it, was found to be heterogeneous in both time and space in terms of the response of test objects. The most and least polluted zones in the reservoir and the river are identified, and water quality is estimated. The water of the Inya R. and the Belovskoe Reservoir showed more pronounced effect on the chlorella and ceryodaphnia than on scenedesmus and daphnia.

영산강 수계의 수질과 식물플랑크톤의 계절적 변화

Environmental parameters and phytoplankton community structure were investigated at four sites of Yeongsan River between April 2010 and December 2011. The standing crops of the phytoplankton ranged from 275 cells∙mL to 58,600 cells∙mL with an average of 5,850 cells ∙mL. The dominant species were Cyclotella sp., Stephanodiscus sp., Aulacoseira granulata, Scenedesmus quadricauda, Pediastrum biwae, Coelastrum sp., Aphnizomenon sp., and Oscillatoria sp.. The most dominant species was Stephanodiscus sp.. The concentration of chlorophyll-a ranged from 2.3 mg∙m to 164.2 mg∙m. The phytoplankton community structure of the survey area was influenced by temperature and rainfall.

Allelopathic inhibition of microalgae by the freshwater stonewort, Chara australis, and a submerged angiosperm, Potamogeton crispus

Eutrophication is a major management issue in shallow lakes worldwide. The role of allelopathy in aquatic systems has received increasing attention as a potential means of controlling algal blooms. Macrophytes with allelopathic potential may play an important role in the restoration of eutrophic lakes. Our objective was to investigate the allelopathic effect of the freshwater stonewort, Chara australis, and the submerged angiosperm, Potamogeton crispus, on microalgae. To detect possible allelopathic effects, we compared the growth of a cyanobacterial species, Anabaena variabilis and a green alga, Scenedesmus quadricauda, in the presence and absence of macrophyte extracts, exudates and live material. We found a significant negative effect of all treatments on A. variabilis, with the strongest effect produced by C. australis. In contrast, no effect of macrophyte extracts was evident on the growth of S. quadricauda. This absence of effect confirmed earlier findings that macrophyte allelochemicals are specific to particular target organisms. Our results suggest that allelopathic macrophytes have the potential to mitigate phytoplankton blooms in systems dominated by A. variabilis and perhaps other cyanobacteria.

QSAR Modeling of Toxicity of Acyclic Quaternary Ammonium Compounds on Scenedesmus Quadricauda Using 2D and 3D Descriptors

Optimized calculation of typical acyclic quaternary ammonium compounds (QACs) was performed at B3LYP/6-311G** level using density functional theory (DFT) method. A two- dimensional quantitative structure-activity relationship (2D-QSAR) model was established with the obtained structure parameters as theoretical descriptors. And then three-dimensional quantitative structure-activity relationship (3D-QSAR) models were built using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) methods respectively. The 2D and 3D QSAR models exhibit optimum stability and predictive ability, revealing that steric and electronic effects influence the toxicity of acyclic QACs to Scenedesmus Quadricauda mostly.

PHOTOACCLIMATION, PHOTOSYNTHESIS, AND GROWTH IN PHYTOPLANKTON

ABSTRACT In this study we have followed various aspects of the photoacclimation of Synechococcus leopoliensis, Isocrysis galbana, and Scenedesmus quadricauda grown at different irradiances. These included changes in the biochemistry, physiology, and ecological fitness of the cells. As cells adapted to lower growth-irradiance levels, chlorophyll (chl) a per cell increased 2.3–7.4-fold. The photosynthetic apparatus changed by increasing the photosynthetic unit size, or the number of reaction centers per cell. The values of the in vivo spectral average, effective optical-absorption cross section (°a*) showed an opposite trend, ranging from 0.010 m2 mg−1 chl a at 15 μmole quanta m−2 s−1 to 0.097 m2 mg−1 chi a at 600 μmole quanta m−2 s−1. The maximum quantum yield, Φmax, increased consistently as growth irradiance decreased from 600 to 15 μmole quanta nr−2 s−1. Light-saturated rates of photosynthesis were considerably higher in all high-light grown cultures than in low-light ones. Respiration rate is greater a...

The hydrophobization of photobioreactors intracavitary surfaces under the long-term cultivation of microalgae cell mass

The experiments on the cultivation of algae Chlorella sp. and Scenedesmus quadricauda on flasks showed that from eight commercially available water-repellent recipes to prevent the fouling of glass surfaces the most effective is to use dimethyldichlorosilane as a 5% solution in isopropanol. The procedure of processing the containers is quite simple and consisted of short-term rinsing of the specified drug and further drying under vacuum at a temperature of 100 - 110 degrees Celsius.

Cr(III) and Cr(VI) Removal from Aqueous Solutions by Cheaply Available Fruit Waste and Algal Biomass

This study compared the effectiveness of different biosorbents, viz. materials commonly present in natural treatment systems (Scenedesmus quadricauda and reed) and commonly produced fruit wastes (orange and banana peel) to remove Cr(III) and Cr(VI) from a synthetic wastewater simulating tannery wastewater. The Cr(III) removal efficiency followed the order S. quadricauda>orange peel>banana peel>reed, whereas the Cr(VI) removal followed the order banana peel>S. quadricauda>reed>orange peel. The chromium biosorption kinetics were governed by the intraparticle diffusion mechanism. Isotherm data obtained using the different biosorbents were fitted to the Langmuir, Freundlich, and SIPS models, revealing that the experimental data followed most closely the monolayer sorption theory-based Langmuir model than the other models. The maximum Cr(III) sorption capacity, calculated using the Langmuir model, was found to be 12 and 9 mg/g for S. quadricauda and orange peel, respectively, and the maximum Cr(VI) sorption capacity calculated for banana peel was 3 mg/g. The influence of biosorbent size, pH, solid-liquid ratio, and competing ions were examined for Cr(III) biosorption by S. quadricauda and orange peel and for Cr(VI) sorption by banana peel. The solution pH was found to be the most influential parameter affecting the biosorption process: whereas pH 5 was found to be optimum for maximum removal of Cr(III), Cr(VI) was best removed at a pH as low as 3. Interference to chromium sorption by various ions revealed that Cr(III) binding onto orange peel occurs through electrostatic forces, whereas Cr(VI) binding onto banana peel through non-electrostatic forces.

Foraging Inhibition in Two Cladocerans Feeding onMicrocystis aeruginosa

Bloom-forming cyanobacteria are known to negatively affect their herbivores, but the possible reasons leading to the foraging inhibition of different cladoceran species are uncertain and controversial so far. Hence, in order to understand how cyanobacteria affect the feeding behavior of cladocerans with different body sizes, feeding rates (FR) of zooplankton cladocerans Daphnia carinata and Moina macrocopa on the mixture of toxic or non-toxic Microcystis aeruginosa with Scenedesmus quadricauda during a 24-h period was investigated. FR of M. macrocopa was found generally low in the mixed toxic Microcystis diets, except for the sudden increase after 8 h of exposure, while FR of D. carinata decreased continuously in the mixed toxic diets. The dynamics of FR of both cladocerans on specific algae was similar to that of the total FR. There is no apparent selectivity displayed for either of the two cladoceran species on the mixed diets. There is no significant difference between the strains of Microcystis, suggesting that the feeding pattern of M. macrocopa maybe more of avoiding Microcystis rather than feeding inhibition resulted from the toxicity of algae. Unlike M. macrocopa, there was a significant difference in D. carinata between the strains of Microcystis over time. The reason for feeding inhibition of D. carinata might be toxicity after continuous exposure to the toxic cyanobacteria.

Biosorption and toxicity responses to arsenite (As[III]) in Scenedesmus quadricauda

Toxicity and biosorption responses to arsenite (As[III]) were examined in a 96-h exposure study using Scenedesmus quadricauda, one of the most popular green algae distributed in freshwaters in China. Results indicated that the pH-dependent distribution of two arsenite species (H2AsO3- and H3AsO3) played an important role in biosorption and toxicity. The undissociated H3AsO3 was more toxic than its monoanionic H2AsO3- through comparison of algal cell numbers, chlorophyll-a contents, and algal ultrastructural changes observed with transmission electron microscopy. An effective biosorption of 89.0mgg−1 at 100mgL−1 As[III] was found in the treatments with an initial pH of 9.3 and 25.2μgg−1 at 0.03mgL−1 As[III] at an initial pH of 8.2 as a result of the predominant species of H2AsO3- under the ambient pH and Eh conditions. Our results imply that S. quadricauda may provide a new means for the removal of toxic arsenite species present in contaminated surface water.

Changes of metal-induced toxicity by H2O2/NO modulators in Scenedesmus quadricauda (Chlorophyceae)

Effect of nitric oxide donor (sodium nitroprusside, SNP, 500 μM) or hydrogen peroxide scavenger (dithiothreitol, DTT, 500 μM) on cadmium (Cd) or copper (Cu) uptake (150 μM solutions) and toxicity using Scenedesmus quadricauda was studied. Combined treatments (Cd or Cu + DTT or SNP) usually ameliorated metal-induced toxicity at the level of pigments, proteins, and mineral nutrients in comparison with respective metal alone. Viability tests (MTT and TTC) showed the lowest values preferentially in Cu treatments, indicating higher toxicity in comparison with Cd. Cd showed low impact on amino acids while strong Cu-induced depletion was mitigated by DTT and SNP. Amount of ROS and NO showed the most pronounced responses in SNP variants being rather reciprocal than parallel and regulated ascorbate peroxidase activity. Blot gel analyses of hsp70 protein did not reveal extensive changes after given exposure period. Phenols were elevated by DTT alone while all Cu treatments revealed depletion. Total Cu content decreased while total Cd content increased in metal + SNP or metal + DTT. Subsequent experiment using lower Cd, SNP or DTT doses (10 and 100 μM) revealed concentration-dependent impact on Cd uptake. Overall, DTT was found to be more suitable for the amelioration of metal-induced toxicity.

Influencing of Amino Acid Composition of Green Freshwater Algae and Cyanobacterium by Methods of Cultivation

Aim: To determine and evaluate amino acid profiles in algal biomass of green freshwater microalgae Chlorella kessleri, Scenedesmus quadricauda and Chlorella sp. and blue-green micro-alga (cyanobacterium) Spirulina platensis cultivated by various methods. To perform the comparison of amino acid contents in algal biomass originated from cultivation methods. Material and Methods: Selected species of green freshwater micro-algae and blue-green microalgea were cultivated under the autotrophic cultivation in laboratory, in an outdoor open circulating cascade-type cultivation apparatus in a thin-layer, in a solar photobioreactor and under the heterotrophic cultivation regime in a fermenter.

Isolation of Two Green Algal Species from Ornamental Fish Hatchery Unit, Biochemical Characterization and Relevance to Fish Sustenance

Algae being already reported to be a pigment and growth enhancers for many ornamental fishes hence a preliminary investigation on algal accrual in the ornamental fish rearing tanks was done. Chlorella vulgaris and Scenedesmus quadricauda were found to be most dominant in the fish tanks. Thus to develop a better understanding of these two algae they were isolated and screened for their growth performance in culture media along with their biochemical and pigment profile. A comparative account on the arrival of certain algal species and the physicochemical characteristics of water in the fish rearing tanks in which the algae were thriving has also been analyzed.

Optimization of malachite green biosorption by green microalgae—Scenedesmus quadricauda and Chlorella vulgaris: Application of response surface methodology

The present study was carried out to optimize the various experimental conditions for biosorption of malachite green (MG) dye onto Scenedesmus quadricauda and Chlorella vulgaris biomass by applying response surface method (RSM). The effects of process parameters, viz. initial MG dye concentration (mg/L), initial solution pH, algae amount (mg/L) and contact time (min) on the dye biosorption were analyzed using Box–Behnken design. The maximum experimental dye removal efficiency of 73.49 and 91.61% for S. quadricauda and C. vulgaris, respectively, was obtained, which was in agreement with calculated values. The FT-IR analysis confirmed the presence of different functional groups on the surface of biosorbents which were responsible for sorption of MG dye. Kinetic studies revealed that experimental data fitted well with the pseudo-second order model. In addition, thermodynamic parameters for dye biosorption were calculated, and negative ΔG° values indicated spontaneous nature of biosorption.

Biodiesel production from microalgal isolates of southern Pakistan and quantification of FAMEs by GC-MS/MS analysis

BackgroundMicroalgae have attracted major interest as a sustainable source for biodiesel production on commercial scale. This paper describes the screening of six microalgal species, Scenedesmus quadricauda, Scenedesmus acuminatus, Nannochloropsis sp., Anabaena sp., Chlorella sp. and Oscillatoria sp., isolated from fresh and marine water resources of southern Pakistan for biodiesel production and the GC-MS/MS analysis of their fatty acid methyl esters (FAMEs).ResultsGrowth rate, biomass productivity and oil content of each algal species have been investigated under autotrophic condition. Biodiesel was produced from algal oil by acid catalyzed transesterification reaction and resulting fatty acid methyl esters (FAMEs) content was analyzed by GC/MS. Fatty acid profiling of the biodiesel, obtained from various microalgal oils showed high content of C-16:0, C-18:0, cis-Δ9C-18:1, cis-Δ11C-18:1 (except Scenedesmus quadricauda) and 10-hydroxyoctadecanoic (except Scenedesmus acuminatus). Absolute amount of C-14:0, C-16:0 and C-18:0 by a validated GC-MS/MS method were found to be 1.5-1.7, 15.0-42.5 and 4.2-18.4 mg/g, respectively, in biodiesel obtained from various microalgal oils. Biodiesel was also characterized in terms of cetane number, kinematic viscosity, density and higher heating value and compared with the standard values.ConclusionSix microalgae of local origin were screened for biodiesel production. A method for absolute quantification of three important saturated fatty acid methyl esters (C-14, C-16 and C-18) by gas chromatography-tandem mass spectrometry (GC-MS/MS), using multiple reactions monitoring (MRM) mode, was employed for the identification and quantification of biodiesels obtained from various microalgal oils. The results suggested that locally found microalgae can be sustainably harvested for the production of biodiesel. This offers the tremendous economic opportunity for an energy-deficient nation.

Influence of barley straw (Hordeum vulgare L.) extract on phytoplankton dominated by Scenedesmus species in laboratory conditions: the importance of the extraction duration

The response of a natural phytoplankton assemblage dominated by algae of the genus Scenedesmus to the addition of barley straw extract was studied in a laboratory experiment. The aim of the study was to compare the inhibiting effect of water extracts obtained by soaking the straw for 1, 2 and 3 months. We analysed the response of four species, Scenedesmus subspicatus, Scenedesmus ecornis, Scenedesmus quadricauda and Scenedesmus acuminatus, during 14 days of their exposure to different types of barley straw extract. S. subspicatus and S. ecornis responded with decreasing numbers only to the addition of the 3-month solution (ANOVA; F = 290.1, p <0.001; and F = 11.8, p <0.01, respectively); the two other species were inhibited by all types of extracts. The results indicate the need for more research on the importance of extraction duration to the inhibitory abilities of barley straw which can be applied in the management of water quality in water bodies.