Scenedesmus Bijugatus Research Articles

Exploring the potential of freshwater algal species for biofuel production

The present study demonstrates the potential of freshwater algal species collected from the natural habitats of Central India for biofuel production. Algal samples were collected from different waterbodies and were microscopically examined in the laboratory. Based on the morphological features using the taxonomic keys, a total of 51 algal species (18 Cyanophyta, 22 Chlorophyta, 7 Bacillariophyta, and 4 Charophyta) were identified. Among them, 18 algal species were successfully purified in the laboratory and tested for their ability to produce biomass and lipid, which are the essential criteria to be qualified as suitable feedstock for biofuel production. The data on specific growth rates suggest that Chlorella vulgaris, Scenedesmus bijugatus, and Nitzschia recta were the fastest growing species, whereas all the members of Cyanophyta showed relatively slower growth. The biomass productivity was higher in C. vulgaris, S. bijugatus, and Anabaena sp., but the lipid production was highest in C. vulgaris followed by Haematococcus sp., whereas the members of Cyanophyta showed the lowest lipid production. Furthermore, we assessed the ability of biomass and lipid production and biochemical parameters of four selected algal species, C. vulgaris, S. bijugatus, Anabaena sp., and N. recta, due to their faster growth, higher biomass and lipid production, and abundance. Based on the cluster analyses of the values of lipid and biomass production of these species against internal N:P ratio, three distinct clusters were noticed, cluster 1: near 50:1, cluster 2: between 30:35, and cluster 3 between 15:20 cellular N:P ratios. High lipid and biomass productivity were observed between the 30:35 N:P ratio. Despite the metabolic significance of N and P for algae, more research is warranted to conclude anything precisely.

Phosphorus deficiency stimulates dominance of Cylindrospermopsis through facilitating cylindrospermopsin-induced alkaline phosphatase secretion: Integrating field and laboratory-based evidences

Potentially toxic Cylindrospermopsis raciborskii blooms are of emerging concerns, as its scale is spreading from tropical regions to high latitudes, increasing the risk of aquatic biota being exposed to cylindrospermopsin (CYN). So far, CYN-producing C. raciborskii strains have only been reported in tropical waters which are commonly phosphorus (P)-deficient, where they can dominate phytoplankton communities. However, the influence of CYN on phytoplankton communities under different P status remains unclear. In this study, we first analyzed the summer observations of 120 tropical reservoirs in Guangdong Province. The proportion of potential CYN-producers was significantly higher in P-deficient and CYN-present reservoirs than that in P-sufficient or CYN-absent ones. This suggested that in P-deficient condition, the potential CYN producers might gain more advantages by the help of CYN. Then, in laboratory experiments we found that upon P deprivation, CYN did not inhibit the cell growth of other algal cells, but significantly stimulates them to secret more alkaline phosphatase (ALP) than in P-sufficient condition. Through transcriptomics, we further revealed that under such P-deficient condition, CYN remarkably induced intracellular nitrogen allocation and protein export system by activating the PIK3/Akt-cGMP/PKG signaling pathways in Scenedesmus bijugatus, thus enhancing its ALP secretion. Our study implies that CYN-induced ALP secretion is facilitated upon P deficiency, thus supporting the dominance of its producers C. raciborskii.

Salinization and wastewater effects on the growth and some cell contents of Scenedesmus bijugatus.

The aim of this study is to determine the effect of salinization and wastewater stresses on the growth, some cellular contents (total soluble proteins, total soluble carbohydrates, nucleic acids, and amino acids composition) and ultrastructure using TEM of unicellular green alga Scenedesmus bijugatus. Treatment of S. bijugatus by NaCl at 10 and 50 mg L−1 significantly increased the growth of this alga and its cellular macro-molecules. While, treatment above this concentration with NaCl significantly inhibited the growth and cellular macro-molecules. On the other hand, treatment by NaCl at the pre-lethal concentration (300 mg L−1) had different effects on its detected amino acids. Whereas, Asp. Acid, Pro, Cys, Val, Iso-leu, leu, Phe.ala and Lys were slightly stimulated with salinization treatment. On contrast the levels of amino acids: Thr, Ser, Glu.acid, Gly, Ala, Mth, His and Arg were markedly inhibited. Ultrastructure examination of treated S. bijugatus by 300 mg L−1 of NaCl for 8 days showed increase of starch granules, shrinkage of cell contents and thickening of cell wall. The recorded data indicated also that treatment by wastewater with all concentrations led to stimulatory effects on their growth and cellular macro-molecules except at 100% wastewater which had inhibitory effects on Asp., Gly., Thr., Ser., Pro., Glu., Ala., Meth., and Cyst., of S. bijugatus. Also, wastewater induced a slight change in the treated S. bijugatus as elevation in starch granules and presence of thylakoid membranes although not clear as in the control.

Nitrogen and phosphate removal by free and immobilised cells of Scenedesmus bijugatus (Kützing) from the Pinang River estuary, Penang, Malaysia

ABSTRACTThis research studied the effects of inorganic nutrient removal by free and immobilized Scenedesmus bijugatus cells, measured by algal growth (i.e., the chlorophyll a concentration) and the efficiency of the uptake of inorganic nutrients by the cells (uptake rate (b) and removal percentage) in water samples from the organically polluted Pinang River estuary (PRE). Water samples from the PRE were collected during low and high tide. S. bijugatus cells had a higher growth rate when incubated in low tide PRE water samples compared to high tide PRE water samples, with a growth rate of 0.29 µgml−1d−1 and 0.06 µgml−1d−1 for free and immobilized cells, respectively. S. bijugatus was able to more efficiently remove nitrogen, especially ammonium (81–94%), compared to phosphate (62–88%) from both low and high tide water samples. S. bijugatus cells in low tide PRE water samples recorded highest phosphate (0.36 mgL−1d−1 and 0.25 mgL−1d−1 for free and immobilized cells, respectively) and ammonium uptake rates (0.44 mgL−1d−1 and 0.29 mgL−1d−1 for free and immobilized cells respectively). Both inorganic nutrient removal and microalgal cell growth were not significantly different between free and immobilized S. bijugatus (p > 0.05). The data obtained indicated that the removal of nutrients by microalgae was affected by salinity and the immobilization technique applied may have good potential for bioremediation.

An integrated approach for biodiesel and bioethanol production from Scenedesmus bijugatus cultivated in a vertical tubular photobioreactor

Algae are considered promising renewable feedstocks for the production of alternative fuels. In this study, an indigenous strain of Scenedesmus bijugatus found commonly in the fresh water bodies was isolated and evaluated for biofuels production. The alga was successfully mass cultivated in the custom made vertical tubular photobioreactor (250L capacity) at semi-continuous mode. During the cultivation period, the volumetric biomass and lipid productivity were assessed. The alga S. bijugatus produced 0.26gL−1d−1 of dry biomass and 63mgL−1d−1 of lipids, respectively. Algal biomass was harvested by a combined harvesting process involving coagulation and flocculation using Iron (III) sulfate and an organic polymer which resulted in 98% harvesting efficiency. Lipid extraction using hexane:diethyl ether (1:2 ratio) resulted in maximum extraction of lipids. This study also examined sequential stages of esterification and transesterification to convert lipids to biodiesel. The maximum biodiesel yield of 0.21g/g of dry biomass was obtained through the acid base catalytic process. The biodiesel fuel properties were tested and observed that most of the properties complying with ASTM D6751 specifications. The lipid extracted residual biomass recorded a yield of 0.158g of bioethanol per g. This study confirmed the potential of lipid extracted biomass for the production of bioethanol to improve the economic feasibility of microalgal biorefinery.

Phytoplankton dynamics and species diversity in a shallow eutrophic, natural mid-altitude lake in Himachal Pradesh (India): role of physicochemical factors

Rewalsar Lake, a mid-altitude, shallow and recreational water body located in the north-western Himalayas, Himachal Pradesh (India) was studied through monthly surveys in two consecutive years (March 2008 to February 2010). Forty-seven species belonging to seven groups of phytoplankton were identified from the lake. Microcystis aeruginosa and Synedra ulna exhibited a perennial habit. Ankistrodesmus falcatus, Chlorella vulgaris, Scenedesmus bijugatus, Chlamydomonas reinhardi, Eudorina elegans, Navicula cuspidate, Synedra ulna, Euglena acus, Euglena oxyuris, Spirulina gomontii, Oscillatoria princeps and Arthrospira khannae were abundant, and Oscillatoria limosa and Microcystis aeruginosa were highly abundant. Twenty-one important criteria were studied, for example, temperature, free carbon dioxide, biochemical oxygen demand, total alkalinity, nitrate, silicate and phosphate, which provide an idea of the portability of water for irrigation and drinking purposes as per the permissible limits given in World Health Organization, Indian Council of Medical Research and Indian Standards Institute standards. Pearson's correlation revealed a significant relationship between physicochemical parameters and different algal groups. Both plankton and chlorophyll a showed a bimodal pattern of fluctuation. High annual mean concentrations of chlorophyll a (mg L−1) were recorded as 11.44 in 2008–09, and 11.04 in 2009–10. As per the Palmer pollution index, 13 pollution-tolerant algal species with a pollution score of 37 were observed. The Central Pollution Control Board categorised the water at Rewalsar Lake as ‘D–E’.

Fresh Water Algae from Vena River Hinganghat Dist. Wardha Maharashtra, India

The present work is a part of survey conducted to study the fresh water algal flora of Vena River of Hinganghat tahsil of Dist. Wardha (M.S,), Twenty one taxa of class Chlorophyceae, Cyanophyceae and Bacillariophyceae were identified from 6 samples. Cosmarium reniforme (Ralf) Arch. and Roth. And Scenedesmus bijugatus (Turp.) Kuetz. were the dominant green algae followed by the remaining other rare species of Scenedesmus Meyen and Staurastrum Meyen ex Ralfs. All these taxa constitute new records for the

Assessment of Changes in the Algal Diversity of Chilika Lagoon after Opening of New Mouth to Bay of Bengal

Eighty one algal taxa comprising of 24 species of Cyanophyta, 2 Rhodophyta, 19 Chlorophyta, 6 Euglenophyta and 30 Bacillariophyceae under Heterokontophyta were recorded in Chilika lagoon in different seasons of 2010-2011 in a survey after opening of new mouth to Bay of Bengal. Of these Cyanobacterium diachlloros, Aphanocapsa marina, Microsystis aeruginosa, Microsystis wesenbergii, Pseudanabena limnetica, Arthospira ambiguum, Oscillatoria perornata, Oscillatoria proteus, Oscillatoria simplicissima under Cyanophyta, Scenedesmus bijugatus, Urenema elongatum under Chlorophyata, Trachelomonas abrupt, Trachelomonas hispida under Euglenopyta and Coscinodiscus subtilis, Navicula amphirhynchus, Navicula major, Gomphonema micropus, Gomphonema olivaceu, Gomphonema sphaerophorum, Cyclotella meneghiniana, Pinnularia subsimilis, Pleurosigma javanicum, Stephanophyxis turris, Synendra tabulata, Stauroneis pusilla and Cymbella affinis under Bacillariophyceae of Heterokontophyta recorded in the survey have not been reported in the lake before opening of the mouth. Maximum number of algal species was observed in winter followed by summer and post monsoon seasons. Northern sector showed maximum algal diversity followed by Central, Southern and Outer channel sectors. The Cyanophytes followed by Chlorophytes were rich in Northern, Central and Southern sectors where as the diatoms were abundant in Outer channel sector and Northern sector. The agarophyte Gracilaria verrucosa recorded in the Outer channel sector of the lagoon for the first time showing extended distribution of the species due to increase in salinity coupled with consistent wave action in the lagoon after opening of the new mouth.

New reports on anti-bacterial and anti-candidal activities of fatty acid methyl esters (FAME) obtained from Scenedesmus bijugatus var. bicellularis biomass

The present study evaluates the efficiency of fatty acid methyl esters (FAMEs) obtained from microalgal (Scenedesmus bijugatus var bicellularis) biomass as an antimicrobial agent against Staphylococcus aureus, Escherichia coli and Candida albicans. The FAME profiles were determined through Gas Chromatography (GC) with a Flame Ionization detector (FID). The FAMEs showed inhibitory activity against all three microorganisms and thereby exhibited both anti-bacterial and anti-candidal activity. GC-FID analysis reveals about 30 different FAMEs. Out of these, various pharmacologically active FAMEs like stearic acid methyl ester (C18:0) (0.6% w/w), oleic acid methyl ester (C18:1) (1% w/w), linoleic acid methyl ester (C18:2) (1.40% w/w), linolenic acid methyl ester (C18:3) (6.26%), eicosapentanoic acid methyl ester (C20:5) (1.13% w/w), erucic acid methyl ester (C22:1) (1.03% w/w) and docosahexenoic acid methyl ester (C22:6) (2.27% w/w) were detected, which accounted for the bioactivity. These results clearly indicate that the FAMEs of S. bijugatus var. bicellularis have strong antimicrobial properties and could thus be used as an effective source against microbial diseases.

Changes in the carbon metabolism in nitrophenolgrown cultures of Nostoc linckia and Scenedesmus bijugatus, isolated from rice soil

The response of photosynthetic metabolism of carbon towards nitrophenol treatment in cultures of Nostoc linckia and Scenedesmus bijugatus was assessed by examining the cellular contents and activities of the enzymes. The starch content and non-reducing sugars were significantly lower in nitrophenol-grown cultures. The alterations were marked in activities of the enzymes involved in starch metabolism. The enhancement in the activity of phosphorylase clearly supports the observed reduction in accumulation of both starch as well als non-reducing sugars. The decreased activities of fructose 1,6-biphosphatase and sucrose phosphate synthase, and the enhanced activity of invertase resulted in low level accumulation of non-reducing sugars. The observed high activity of acid phosphatase resulted in concomitant decrease in levels of starch.

Responses of glutathione cycle enzymes and glutathione metabolism to copper stress in Scenedesmus bijugatus

Enzymes of glutathione metabolism and GSH content in copper-treated Scenedesmus bijugatus cells and the synthesis of metal-binding peptides are reported in this investigation. Progressive depletion of GSH content in the cells was observed with increasing concentrations of copper. There was an increase in the protein thiol content while the non-protein thiol content decreased. There was an initial elevation and later decrease in the hydrogen peroxide level in the cells. Copper stress increased the activities of γ-glutamylcysteine synthetase, GSH S-transferase and GSH-peroxidase and decreased the activity of GSSG-reductase. These results suggest that copper alters the equilibrium between synthesis and utilization of GSH either due to its antioxidant role or by serving as a precursor in the synthesis of phytochelatins.

Algal Flora of Egyptian Soils 1. The occurrence of Cyanobacteria and Algae in some habitats

The culturing of reclaimed soils (from Burg El-Arab and Modiriya El-Tahrir areas) and old soils of Nile Valley (from Dakahlia , Giza and Luxor areas) on Myre's, Chu's No 10 and Beijerinck's artifiial media contributed to the isolation and identification of 78 algal taxa related to 31 genera belonging to Cyanophycophyta (52.6 %), Chlorophycophyta (28.2%), Xanthophycophyta (8.9 %), Bacillariophycophyta (7.7 %) and Euglenophycophyta (2.6 %). No single region contains all taxa recorded in the investigated soils. Although, each soil had its own characteristic algal flora and edaphic factors , they participated mostly in the production of Chlamydomonas komma Skuja, followed by Amorphonostoc punctiforme (Kutz.) Elenk., Stratonostoc linckia f. spongiaeforme (Ag.) Kutz, Calothrix elenkinii Kossinsk., Hantzschia amphioxys f. capitata O. Mull., Chlorocloster raphidioides Patch., Chlorella vulgaris Beij. and Scenedesmus bijugatus (Turp.) Kutz. The edaphic properties showed that slightly alkaline to alkaline pH reaction favoured the prevailence of members of Cyanobacteria in the investigated soils. The representation of iron - tolerated taxon Chloridella ferruginea Pasch. between the yellow green algae recorded in Dakahlia emphasized the relativley high level of iron in this soil. The presentwork added 38 new taxa to Egyptian algal flora. However, full descriptions as well as expressive illustrations and / or photos of the new reccords will be the subject of a future publication.

Effects of Nutrients at Different Salinities on Growth of the Freshwater Green Alga Scenedesmus bijugatus in Water of Narendra Pond, Puri, Orissa

AbstractThe growth and biochemical composition of Scenedesmus bijugatus grown in normal and nutrient enriched Narendra Pond water was evaluated at different levels of salinity. In normal pond water (NPW) the growth was enhanced when the initial salinity of the water was doubled (to 7.2 mmol/l) but further salinity increase caused growth retardation. In nutrient enriched pond water (NEW), however, the maximum growth occurred in the culture containing 29 mmol/l of NaCl. At growth retarding salt concentrations the chlorophyll, carbohydrate, protein and lipid contents per cell decreased in both NPW and NEW while the proline content first increased and was then reduced. All nutrients, taken separately or in combination, caused growth enhancement of the alga at the three selected salinity levels. The alga showed a better halotolerance when enriched with nitrogen or phosphorus.

Effective Concentrations of Nitrophenolics Toward Growth Yield of Selected Microalgae and Cyanobacteria Isolated from Soil

The effective concentrations (EC), which cause a certain percentage of inhibition in growth yield, of four nitrophenolics ( o-nitrophenol, m-nitrophenol, p-nitrophenol (PNP), and 2,4-dinitrophenol) and the major metabolites of PNP reduction ( p-nitrosophenol and p-aminophenol) toward growth of two microalgae ( Chlorella vulgaris and Scenedesmus bijugatus) and two cyanobacteria ( Nostoc muscorum and Nostoc linckia), all isolated from soil, were determined following linear regression analysis. The EC 50 values of the selected toxicants toward the test organisms were in the range of 32 to 227 μg ml −1. Such a wide range in EC figures emphasizes the need for a prior determination of EC values of a toxicant before establishing its toxicity pattern toward a nontarget microorganism.

Salt induced changes in the growth of Chlorococcum humicolo and Scenedesmus bijugatus under nutrient limited cultures.

Due to climatic changes in tropics, saline water bodies are often subject to natural fluctuations of salinity through precipitation, dessication, drought conditions or anthropogenic interference. Growth and persistence of algae under these conditions require physiological tolerance and/or resistant stages in the life cycle. Salinity, which ranges from 95.9-174.7 mg/L as NaCI, is considered as an important parameter for the Indradyumna pond (485 x 396 sq ft, maximum depth 5 m) of Puri, Orissa for it is located at a distance of 1 km from the Bay of Bengal. The fluctuation of salinity level of the pond has been observed during 1988-1991 mostly due to excessive use by innumerable number of pilgrims all over the year (Dash 1992). Increased salinity favors growth of cyanobacteria because this is the only group of photoautotrophic plankton taxa requiring Na + for growth (Allen and Arnon 1955). Green algal species like halotolerant planktonic algae (Hellebust and Le Gresley 1985), Chlorella, Ankistrodesmus and Scenedesmus (Kessler 1980) have also been found to be favored by increased salinity. However, the rationale of studying salinity tolerance of algae under nutrient limited conditions seems to be more appropriate in the bioassay method because it is established that the susceptibility / resistance characteristic of an algal species to external stress is nutritionally determined (Herbert and Bradley 1989; Mohapatra and Mohanty 1992). Accordingly, it was decided to see the effects of salinity stress on two indigenous phytoplankton species viz., Chlorococcum humicolo (Nag) Rabenh. and Scenedem~us bijugatus KUtz. in culture with differential nutrient enrichment using the sterile pond water as medium.

Removal of nitrogen and phosphorus by immobilized cells of Chlorella vulgaris and Scenedesmus bijugatus isolated from soil

The efficiency in removal of ammoniacal-nitrogen and orthophosphate-phosphorus from continuous flow cultures was determined using two soil microalgae, Chlorella vulgaris and Scenedesmus bijugatus, entrapped in 4-mm calcium-alginate beads. Beads each stocked with 10 8 cells of both cultures removed 71 to 79% more nitrogen and 52 to 82% more phosphorus within 6 h compared to those with a stocking density of 10 5 cells bead −1. C. vulgaris was more efficient in the removal of both nutrients than S. bijugatus. Exponentially growing cells of the two isolates effected greater uptake of phosphorus, whereas the age of the cultures was found to have no direct impact on the removal of nitrogen.

The use of unicellular soil green algae for insecticide bioassay

Two unicellular green algae, Chorella vulgaris and Scenedesmus bijugatus, isolated from soil, were evaluated for their use in the insecticide bioassay employing agar diffusion technique. The minimum detection limits for quinalphos, cypermethrin, fenvalerate, carbofuran and carbaryl, as evidenced by a clear zone around the diffusion source on algal lawn, were in the range of 2–4 μg while monocrotophos could be detected only at >20-μg levels. The results of the present assay are comparable to those of the other toxicity tests.

Effects of carbofuran and carbaryl on the growth of a green alga and two cyanobacteria isolated from a rice soil

Two methylcarbamate insecticides, carbofuran and carbaryl, were assessed for their effects on a green unicellular alga, Scenedesmus bijugatus, and two cyanobacteria, Synechococcus elongatus and Nostoc linckia, all isolated from a rice soil. In laboratory studies, both insecticides up to 20 μg ml −1 concentration significantly increased the cell number of S. bijugatus. Synechococcus elongatus was highly sensitive, 5 μg ml −1 of each chemical being lethal. Concentrations, up to 20 or 50 μg ml −1, of the two insecticides initially increased chlorophyll a in N. linckia significantly, which again led to a subsequent inhibition. In general, carbaryl was more toxic than carbofuran to all the test organisms.

Physiology of phytoplankton in relation to metal concentration Effect of cadmium on Scenedesmus bijugatus and Nitzschia palea

The effect of Cd at sublethal concentrations on pure cultures of S. bijugatus and N. palea was studied with special reference to their physiology during exponential growth phase. Photosynthetic productivity, respiration, pH, biomass, pigments, carbohydrate, protein, lipid as well as nutrient uptake were selected to study the comprehensive effect of the metal. The physiology of the species was significantly affected by Cd during the exponential growth phase and altered the ratio of carbohydrate, protein and lipid in the test species.

Influence of cypermethrin and fenvalerate on a green alga and three cyanobacteria isolated from soil

The effects of two pyrethroid insecticides, cypermethrin and fenvalerate, on a green alga ( Scenedesmus bijugatus) and three species of cyanobacteria ( Synechococcus elongatus, Nostoc linckia, and Phormidium tenue), all isolated from a black cotton soil, were studied using either cell number or chlorophyll a as toxicity criterion. All the four species were either unaffected or stimulated at 5 μg ml −1. Of the two insecticides, cypermethrin, at 10 to 50 μg ml −1, inhibited S. bijugatus while these concentrations stimulated or only slightly inhibited the growth of S. elongatus. There was a significant inhibition in the growth of S. bijugatus and stimulation in S. elongatus with 10 to 50 μg ml −1 fenvalerate. The growth of N. linckia was enhanced by both insecticides while P. tenue was significantly affected.